auto import from //depot/cupcake/@135843

69 files changed, 0 insertions, 12768 deletions

diff --git a/contrib/gregbook/COPYING b/contrib/gregbook/COPYING
deleted file mode 100644
index d60c31a..0000000
--- a/contrib/gregbook/COPYING
+++ /dev/null
@@ -1,340 +0,0 @@
-		    GNU GENERAL PUBLIC LICENSE
-		       Version 2, June 1991
-
- Copyright (C) 1989, 1991 Free Software Foundation, Inc.
-     59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
- Everyone is permitted to copy and distribute verbatim copies
- of this license document, but changing it is not allowed.
-
-			    Preamble
-
-  The licenses for most software are designed to take away your
-freedom to share and change it.  By contrast, the GNU General Public
-License is intended to guarantee your freedom to share and change free
-software--to make sure the software is free for all its users.  This
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-Foundation's software and to any other program whose authors commit to
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-the GNU Library General Public License instead.)  You can apply it to
-your programs, too.
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-
-		    GNU GENERAL PUBLIC LICENSE
-   TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
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-  0. This License applies to any program or other work which contains
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-This section is intended to make thoroughly clear what is believed to
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-
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-  9. The Free Software Foundation may publish revised and/or new versions
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-later version", you have the option of following the terms and conditions
-either of that version or of any later version published by the Free
-Software Foundation.  If the Program does not specify a version number of
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-  10. If you wish to incorporate parts of the Program into other free
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-			    NO WARRANTY
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-  11. BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY
-FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW.  EXCEPT WHEN
-OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES
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-  12. IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
-WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR
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-INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING
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-PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE
-POSSIBILITY OF SUCH DAMAGES.
-
-		     END OF TERMS AND CONDITIONS
-
-	    How to Apply These Terms to Your New Programs
-
-  If you develop a new program, and you want it to be of the greatest
-possible use to the public, the best way to achieve this is to make it
-free software which everyone can redistribute and change under these terms.
-
-  To do so, attach the following notices to the program.  It is safest
-to attach them to the start of each source file to most effectively
-convey the exclusion of warranty; and each file should have at least
-the "copyright" line and a pointer to where the full notice is found.
-
-    <one line to give the program's name and a brief idea of what it does.>
-    Copyright (C) <year>  <name of author>
-
-    This program is free software; you can redistribute it and/or modify
-    it under the terms of the GNU General Public License as published by
-    the Free Software Foundation; either version 2 of the License, or
-    (at your option) any later version.
-
-    This program is distributed in the hope that it will be useful,
-    but WITHOUT ANY WARRANTY; without even the implied warranty of
-    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-    GNU General Public License for more details.
-
-    You should have received a copy of the GNU General Public License
-    along with this program; if not, write to the Free Software
-    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
-
-
-Also add information on how to contact you by electronic and paper mail.
-
-If the program is interactive, make it output a short notice like this
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-    Gnomovision version 69, Copyright (C) year  name of author
-    Gnomovision comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
-    This is free software, and you are welcome to redistribute it
-    under certain conditions; type `show c' for details.
-
-The hypothetical commands `show w' and `show c' should show the appropriate
-parts of the General Public License.  Of course, the commands you use may
-be called something other than `show w' and `show c'; they could even be
-mouse-clicks or menu items--whatever suits your program.
-
-You should also get your employer (if you work as a programmer) or your
-school, if any, to sign a "copyright disclaimer" for the program, if
-necessary.  Here is a sample; alter the names:
-
-  Yoyodyne, Inc., hereby disclaims all copyright interest in the program
-  `Gnomovision' (which makes passes at compilers) written by James Hacker.
-
-  <signature of Ty Coon>, 1 April 1989
-  Ty Coon, President of Vice
-
-This General Public License does not permit incorporating your program into
-proprietary programs.  If your program is a subroutine library, you may
-consider it more useful to permit linking proprietary applications with the
-library.  If this is what you want to do, use the GNU Library General
-Public License instead of this License.
diff --git a/contrib/gregbook/LICENSE b/contrib/gregbook/LICENSE
deleted file mode 100644
index d956717..0000000
--- a/contrib/gregbook/LICENSE
+++ /dev/null
@@ -1,50 +0,0 @@
-  ---------------------------------------------------------------------------
-
-      Copyright (c) 1998-2008 Greg Roelofs.  All rights reserved.
-
-      This software is provided "as is," without warranty of any kind,
-      express or implied.  In no event shall the author or contributors
-      be held liable for any damages arising in any way from the use of
-      this software.
-
-      The contents of this file are DUAL-LICENSED.  You may modify and/or
-      redistribute this software according to the terms of one of the
-      following two licenses (at your option):
-
-
-      LICENSE 1 ("BSD-like with advertising clause"):
-
-      Permission is granted to anyone to use this software for any purpose,
-      including commercial applications, and to alter it and redistribute
-      it freely, subject to the following restrictions:
-
-      1. Redistributions of source code must retain the above copyright
-         notice, disclaimer, and this list of conditions.
-      2. Redistributions in binary form must reproduce the above copyright
-         notice, disclaimer, and this list of conditions in the documenta-
-         tion and/or other materials provided with the distribution.
-      3. All advertising materials mentioning features or use of this
-         software must display the following acknowledgment:
-
-            This product includes software developed by Greg Roelofs
-            and contributors for the book, "PNG: The Definitive Guide,"
-            published by O'Reilly and Associates.
-
-
-      LICENSE 2 (GNU GPL v2 or later):
-
-      This program is free software; you can redistribute it and/or modify
-      it under the terms of the GNU General Public License as published by
-      the Free Software Foundation; either version 2 of the License, or
-      (at your option) any later version.
-
-      This program is distributed in the hope that it will be useful,
-      but WITHOUT ANY WARRANTY; without even the implied warranty of
-      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-      GNU General Public License for more details.
-
-      You should have received a copy of the GNU General Public License
-      along with this program; if not, write to the Free Software Foundation,
-      Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
-
-  ---------------------------------------------------------------------------
diff --git a/contrib/gregbook/Makefile.mingw32 b/contrib/gregbook/Makefile.mingw32
deleted file mode 100644
index e70a59a..0000000
--- a/contrib/gregbook/Makefile.mingw32
+++ /dev/null
@@ -1,130 +0,0 @@
-# Sample makefile for rpng-win / rpng2-win / wpng using mingw32-gcc and make.
-# Greg Roelofs
-# Last modified:  2 June 2007
-#
-#	The programs built by this makefile are described in the book,
-#	"PNG:  The Definitive Guide," by Greg Roelofs (O'Reilly and
-#	Associates, 1999).  Go buy a copy, eh?  Well, OK, it's not
-#	generally for sale anymore, but it's the thought that counts,
-#	right?  (Hint:  http://www.libpng.org/pub/png/book/ )
-#
-# Invoke this makefile from a DOS-prompt window via:
-#
-#	make -f Makefile.mingw32
-#
-# This makefile assumes libpng and zlib have already been built or downloaded
-# and are in subdirectories at the same level as the current subdirectory
-# (as indicated by the PNGDIR and ZDIR macros below).  It makes no assumptions
-# at all about the mingw32 installation tree (W32DIR).  Edit as appropriate.
-#
-# Note that the names of the dynamic and static libpng and zlib libraries
-# used below may change in later releases of the libraries.  This makefile
-# builds both statically and dynamically linked executables by default.
-# (You need only one set, but for testing it can be handy to have both.)
-
-
-# macros --------------------------------------------------------------------
-
-#PNGDIR = ../..#		for libpng-x.y.z/contrib/gregbook builds
-PNGDIR = ../libpng-win32
-PNGINC = -I$(PNGDIR)
-PNGLIBd = $(PNGDIR)/libpng.dll.a	# dynamically linked
-PNGLIBs = $(PNGDIR)/libpng.a		# statically linked, local libpng
-
-#ZDIR = ../../../zlib-win32#	for libpng-x.y.z/contrib/gregbook builds
-ZDIR = ../zlib-win32
-ZINC = -I$(ZDIR)
-ZLIBd = $(ZDIR)/libzdll.a
-ZLIBs = $(ZDIR)/libz.a
-
-# change this to be the path where mingw32 installs its stuff:
-W32DIR =
-#W32DIR = /usr/local/cross-tools/i386-mingw32msvc
-W32INC = -I$(W32DIR)/include
-W32LIB = $(W32DIR)/lib/libuser32.a $(W32DIR)/lib/libgdi32.a
-
-CC = gcc
-#CC = i386-mingw32msvc-gcc #	e.g., Linux -> Win32 cross-compilation
-LD = $(CC)
-RM = rm -f
-CFLAGS = -O -Wall $(INCS) $(MINGW_CCFLAGS)
-# [note that -Wall is a gcc-specific compilation flag ("most warnings on")]
-# [-ansi, -pedantic and -W can also be used]
-LDFLAGS = $(MINGW_LDFLAGS)
-O = .o
-E = .exe
-
-INCS = $(PNGINC) $(ZINC) $(W32INC)
-RLIBSd = $(PNGLIBd) $(ZLIBd) $(W32LIB) -lm
-RLIBSs = $(PNGLIBs) $(ZLIBs) $(W32LIB) -lm
-WLIBSd = $(PNGLIBd) $(ZLIBd)
-WLIBSs = $(PNGLIBs) $(ZLIBs)
-
-RPNG   = rpng-win
-RPNG2  = rpng2-win
-WPNG   = wpng
-
-ROBJSd  = $(RPNG)$(O) readpng.pic$(O)
-ROBJS2d = $(RPNG2)$(O) readpng2.pic$(O)
-WOBJSd  = $(WPNG)$(O) writepng.pic$(O)
-
-RPNGs  = $(RPNG)-static
-RPNG2s = $(RPNG2)-static
-WPNGs  = $(WPNG)-static
-
-ROBJSs  = $(RPNG)$(O) readpng$(O)
-ROBJS2s = $(RPNG2)$(O) readpng2$(O)
-WOBJSs  = $(WPNG)$(O) writepng$(O)
-
-STATIC_EXES  = $(RPNGs)$(E) $(RPNG2s)$(E) $(WPNGs)$(E)
-DYNAMIC_EXES = $(RPNG)$(E) $(RPNG2)$(E) $(WPNG)$(E)
-
-EXES = $(STATIC_EXES) $(DYNAMIC_EXES)
-
-
-# implicit make rules -------------------------------------------------------
-
-.c$(O):
-	$(CC) -c $(CFLAGS) $<
-
-%.pic$(O): %.c
-	$(CC) -c $(CFLAGS) -DPNG_BUILD_DLL -o $@ $<
-
-
-# dependencies --------------------------------------------------------------
-
-all:  $(EXES)
-
-$(RPNGs)$(E): $(ROBJSs)
-	$(LD) $(LDFLAGS) -o $@ $(ROBJSs) $(RLIBSs)
-
-$(RPNG)$(E): $(ROBJSd)
-	$(LD) $(LDFLAGS) -o $@ $(ROBJSd) $(RLIBSd)
-
-$(RPNG2s)$(E): $(ROBJS2s)
-	$(LD) $(LDFLAGS) -o $@ $(ROBJS2s) $(RLIBSs)
-
-$(RPNG2)$(E): $(ROBJS2d)
-	$(LD) $(LDFLAGS) -o $@ $(ROBJS2d) $(RLIBSd)
-
-$(WPNGs)$(E): $(WOBJSs)
-	$(LD) $(LDFLAGS) -o $@ $(WOBJSs) $(WLIBSs)
-
-$(WPNG)$(E): $(WOBJSd)
-	$(LD) $(LDFLAGS) -o $@ $(WOBJSd) $(WLIBSd)
-
-$(RPNG)$(O):	$(RPNG).c readpng.h
-$(RPNG2)$(O):	$(RPNG2).c readpng2.h
-$(WPNG)$(O):	$(WPNG).c writepng.h
-
-readpng$(O) readpng.pic$(O):	readpng.c readpng.h
-readpng2$(O) readpng2.pic$(O):	readpng2.c readpng2.h
-writepng$(O) writepng.pic$(O):	writepng.c writepng.h
-
-
-# maintenance ---------------------------------------------------------------
-
-clean:
-	$(RM) $(EXES)
-	$(RM) $(ROBJSs) $(ROBJS2s) $(WOBJSs)
-	$(RM) $(ROBJSd) $(ROBJS2d) $(WOBJSd)
diff --git a/contrib/gregbook/Makefile.sgi b/contrib/gregbook/Makefile.sgi
deleted file mode 100644
index e3ca6ce..0000000
--- a/contrib/gregbook/Makefile.sgi
+++ /dev/null
@@ -1,104 +0,0 @@
-# Sample makefile for rpng-x / rpng2-x / wpng for SGI using cc and make.
-# Greg Roelofs
-# Last modified:  7 March 2002
-#
-#	The programs built by this makefile are described in the book,
-#	"PNG:  The Definitive Guide," by Greg Roelofs (O'Reilly and
-#	Associates, 1999).  Go buy a copy, eh?  Buy some for friends
-#	and family, too.  (Not that this is a blatant plug or anything.)
-#
-# Invoke this makefile from a shell prompt in the usual way; for example:
-#
-#	make -f Makefile.sgi
-#
-# This makefile assumes libpng and zlib have already been built or downloaded
-# and are both installed in /usr/local/{include,lib} (as indicated by the
-# PNG* and Z* macros below).  Edit as appropriate--choose only ONE each of
-# the PNGINC, PNGLIB, ZINC and ZLIB lines.
-#
-# This makefile builds dynamically linked executables (against libpng and zlib,
-# that is), but that can be changed by uncommenting the appropriate PNGLIB and
-# ZLIB lines.
-
-
-# macros --------------------------------------------------------------------
-
-PNGINC = -I/usr/local/include/libpng12
-PNGLIB = -L/usr/local/lib -lpng12	  # dynamically linked against libpng
-#PNGLIB = /usr/local/lib/libpng12.a # statically linked against libpng
-# or:
-#PNGINC = -I../..
-#PNGLIB = -L../.. -lpng
-#PNGLIB = ../../libpng.a
-
-ZINC = -I/usr/local/include
-ZLIB = -L/usr/local/lib -lz		# dynamically linked against zlib
-#ZLIB = /usr/local/lib/libz.a		# statically linked against zlib
-#ZINC = -I../zlib
-#ZLIB = -L../zlib -lz
-#ZLIB = ../../../zlib/libz.a
-
-XINC = -I/usr/include/X11		# old-style, stock X distributions
-XLIB = -L/usr/lib/X11 -lX11
-#XINC = -I/usr/openwin/include    	# Sun workstations (OpenWindows)
-#XLIB = -L/usr/openwin/lib -lX11
-#XINC = -I/usr/X11R6/include		# new X distributions (XFree86, etc.)
-#XLIB = -L/usr/X11R6/lib -lX11
-
-INCS = $(PNGINC) $(ZINC) $(XINC)
-RLIBS = $(PNGLIB) $(ZLIB) $(XLIB) -lm
-WLIBS = $(PNGLIB) $(ZLIB)
-
-CC = cc
-LD = cc
-RM = rm -f
-# ABI must be the same as that used to build libpng.
-ABI=
-CFLAGS = $(ABI) -O -fullwarn $(INCS)
-LDFLAGS = $(ABI)
-O = .o
-E =
-
-RPNG  = rpng-x
-RPNG2 = rpng2-x
-WPNG  = wpng
-
-ROBJS  = $(RPNG)$(O) readpng$(O)
-ROBJS2 = $(RPNG2)$(O) readpng2$(O)
-WOBJS  = $(WPNG)$(O) writepng$(O)
-
-EXES = $(RPNG)$(E) $(RPNG2)$(E) $(WPNG)$(E)
-
-
-# implicit make rules -------------------------------------------------------
-
-.c$(O):
-	$(CC) -c $(CFLAGS) $<
-
-
-# dependencies --------------------------------------------------------------
-
-all:  $(EXES)
-
-$(RPNG)$(E): $(ROBJS)
-	$(LD) $(LDFLAGS) -o $@ $(ROBJS) $(RLIBS)
-
-$(RPNG2)$(E): $(ROBJS2)
-	$(LD) $(LDFLAGS) -o $@ $(ROBJS2) $(RLIBS)
-
-$(WPNG)$(E): $(WOBJS)
-	$(LD) $(LDFLAGS) -o $@ $(WOBJS) $(WLIBS)
-
-$(RPNG)$(O):	$(RPNG).c readpng.h
-$(RPNG2)$(O):	$(RPNG2).c readpng2.h
-$(WPNG)$(O):	$(WPNG).c writepng.h
-
-readpng$(O):	readpng.c readpng.h
-readpng2$(O):	readpng2.c readpng2.h
-writepng$(O):	writepng.c writepng.h
-
-
-# maintenance ---------------------------------------------------------------
-
-clean:
-	$(RM) $(EXES) $(ROBJS) $(ROBJS2) $(WOBJS)
diff --git a/contrib/gregbook/Makefile.unx b/contrib/gregbook/Makefile.unx
deleted file mode 100644
index 7ff65bf..0000000
--- a/contrib/gregbook/Makefile.unx
+++ /dev/null
@@ -1,132 +0,0 @@
-# Sample makefile for rpng-x / rpng2-x / wpng using gcc and make.
-# Greg Roelofs
-# Last modified:  2 June 2007
-#
-#	The programs built by this makefile are described in the book,
-#	"PNG:  The Definitive Guide," by Greg Roelofs (O'Reilly and
-#	Associates, 1999).  Go buy a copy, eh?  Well, OK, it's not
-#	generally for sale anymore, but it's the thought that counts,
-#	right?  (Hint:  http://www.libpng.org/pub/png/book/ )
-#
-# Invoke this makefile from a shell prompt in the usual way; for example:
-#
-#	make -f Makefile.unx
-#
-# This makefile assumes libpng and zlib have already been built or downloaded
-# and are installed in /usr/local/{include,lib} or as otherwise indicated by
-# the PNG* and Z* macros below.  Edit as appropriate--choose only ONE each of
-# the PNGINC, PNGLIBd, PNGLIBs, ZINC, ZLIBd and ZLIBs lines.
-#
-# This makefile builds both dynamically and statically linked executables
-# (against libpng and zlib, that is), but that can be changed by modifying
-# the "EXES =" line.  (You need only one set, but for testing it can be handy
-# to have both.)
-
-
-# macros --------------------------------------------------------------------
-
-#PNGDIR = /usr/local/lib
-#PNGINC = -I/usr/local/include/libpng12
-#PNGLIBd = -L$(PNGDIR) -lpng12 # dynamically linked, installed libpng
-#PNGLIBs = $(PNGDIR)/libpng12.a # statically linked, installed libpng
-# or:
-PNGDIR = ../..#	this one is for libpng-x.y.z/contrib/gregbook builds
-#PNGDIR = ../libpng
-PNGINC = -I$(PNGDIR)
-PNGLIBd = -Wl,-rpath,$(PNGDIR) -L$(PNGDIR) -lpng12	# dynamically linked
-PNGLIBs = $(PNGDIR)/libpng.a		# statically linked, local libpng
-
-ZDIR = /usr/local/lib
-#ZDIR = /usr/lib64
-ZINC = -I/usr/local/include
-ZLIBd = -L$(ZDIR) -lz			# dynamically linked against zlib
-ZLIBs = $(ZDIR)/libz.a			# statically linked against zlib
-# or:
-#ZDIR = ../zlib
-#ZINC = -I$(ZDIR)
-#ZLIBd = -Wl,-rpath,$(ZDIR) -L$(ZDIR) -lz  # -rpath allows in-place testing
-#ZLIBs = $(ZDIR)/libz.a
-
-#XINC = -I/usr/include			# old-style, stock X distributions
-#XLIB = -L/usr/lib/X11 -lX11		#  (including SGI IRIX)
-#XINC = -I/usr/openwin/include		# Sun workstations (OpenWindows)
-#XLIB = -L/usr/openwin/lib -lX11
-XINC = -I/usr/X11R6/include		# new X distributions (X.org, etc.)
-XLIB = -L/usr/X11R6/lib -lX11
-#XLIB = -L/usr/X11R6/lib64 -lX11	# e.g., Red Hat on AMD64
-
-INCS = $(PNGINC) $(ZINC) $(XINC)
-RLIBSd = $(PNGLIBd) $(ZLIBd) $(XLIB) -lm
-RLIBSs = $(PNGLIBs) $(ZLIBs) $(XLIB) -lm
-WLIBSd = $(PNGLIBd) $(ZLIBd) -lm
-WLIBSs = $(PNGLIBs) $(ZLIBs)
-
-CC = gcc
-LD = gcc
-RM = rm -f
-CFLAGS = -O -Wall $(INCS) -DFEATURE_LOOP
-# [note that -Wall is a gcc-specific compilation flag ("most warnings on")]
-# [-ansi, -pedantic and -W can also be used]
-LDFLAGS =
-O = .o
-E =
-
-RPNG   = rpng-x
-RPNG2  = rpng2-x
-WPNG   = wpng
-
-RPNGs  = $(RPNG)-static
-RPNG2s = $(RPNG2)-static
-WPNGs  = $(WPNG)-static
-
-ROBJS  = $(RPNG)$(O) readpng$(O)
-ROBJS2 = $(RPNG2)$(O) readpng2$(O)
-WOBJS  = $(WPNG)$(O) writepng$(O)
-
-STATIC_EXES  = $(RPNGs)$(E) $(RPNG2s)$(E) $(WPNGs)$(E)
-DYNAMIC_EXES = $(RPNG)$(E) $(RPNG2)$(E) $(WPNG)$(E)
-
-EXES = $(STATIC_EXES) $(DYNAMIC_EXES)
-
-
-# implicit make rules -------------------------------------------------------
-
-.c$(O):
-	$(CC) -c $(CFLAGS) $<
-
-
-# dependencies --------------------------------------------------------------
-
-all:  $(EXES)
-
-$(RPNGs)$(E): $(ROBJS)
-	$(LD) $(LDFLAGS) -o $@ $(ROBJS) $(RLIBSs)
-
-$(RPNG)$(E): $(ROBJS)
-	$(LD) $(LDFLAGS) -o $@ $(ROBJS) $(RLIBSd)
-
-$(RPNG2s)$(E): $(ROBJS2)
-	$(LD) $(LDFLAGS) -o $@ $(ROBJS2) $(RLIBSs)
-
-$(RPNG2)$(E): $(ROBJS2)
-	$(LD) $(LDFLAGS) -o $@ $(ROBJS2) $(RLIBSd)
-
-$(WPNGs)$(E): $(WOBJS)
-	$(LD) $(LDFLAGS) -o $@ $(WOBJS) $(WLIBSs)
-
-$(WPNG)$(E): $(WOBJS)
-	$(LD) $(LDFLAGS) -o $@ $(WOBJS) $(WLIBSd)
-
-$(RPNG)$(O):	$(RPNG).c readpng.h
-$(RPNG2)$(O):	$(RPNG2).c readpng2.h
-$(WPNG)$(O):	$(WPNG).c writepng.h
-
-readpng$(O):	readpng.c readpng.h
-readpng2$(O):	readpng2.c readpng2.h
-writepng$(O):	writepng.c writepng.h
-
-
-# maintenance ---------------------------------------------------------------
-
-clean:
-	$(RM) $(EXES) $(ROBJS) $(ROBJS2) $(WOBJS)
diff --git a/contrib/gregbook/Makefile.w32 b/contrib/gregbook/Makefile.w32
deleted file mode 100644
index 3c08085..0000000
--- a/contrib/gregbook/Makefile.w32
+++ /dev/null
@@ -1,113 +0,0 @@
-# Sample makefile for rpng-win / rpng2-win / wpng using MSVC and NMAKE.
-# Greg Roelofs
-# Last modified:  2 June 2007
-#
-#	The programs built by this makefile are described in the book,
-#	"PNG:  The Definitive Guide," by Greg Roelofs (O'Reilly and
-#	Associates, 1999).  Go buy a copy, eh?  Well, OK, it's not
-#	generally for sale anymore, but it's the thought that counts,
-#	right?  (Hint:  http://www.libpng.org/pub/png/book/ )
-#
-# Invoke this makefile from a DOS prompt window via:
-#
-#	%devstudio%\vc\bin\vcvars32.bat
-#	nmake -nologo -f Makefile.w32
-#
-# where %devstudio% is the installation directory for MSVC / DevStudio.  If
-# you get "environment out of space" errors, create a desktop shortcut with
-# "c:\windows\command.com /e:4096" as the program command line and set the
-# working directory to this directory.  Then double-click to open the new
-# DOS-prompt window with a bigger environment and retry the commands above.
-# 
-# This makefile assumes libpng and zlib have already been built or downloaded
-# and are in subdirectories at the same level as the current subdirectory
-# (as indicated by the PNGPATH and ZPATH macros below).  Edit as appropriate.
-#
-# Note that the names of the dynamic and static libpng and zlib libraries
-# used below may change in later releases of the libraries.  This makefile
-# builds statically linked executables, but that can be changed by uncom-
-# menting the appropriate PNGLIB and ZLIB lines.
-
-!include <ntwin32.mak>
-
-
-# macros --------------------------------------------------------------------
-
-PNGPATH = ../libpng
-PNGINC = -I$(PNGPATH)
-#PNGLIB = $(PNGPATH)/pngdll.lib
-PNGLIB = $(PNGPATH)/libpng.lib
-
-ZPATH = ../zlib
-ZINC = -I$(ZPATH)
-#ZLIB = $(ZPATH)/zlibdll.lib
-ZLIB = $(ZPATH)/zlibstat.lib
-
-WINLIBS = -defaultlib:user32.lib gdi32.lib
-# ["real" apps may also need comctl32.lib, comdlg32.lib, winmm.lib, etc.]
-
-INCS = $(PNGINC) $(ZINC)
-RLIBS = $(PNGLIB) $(ZLIB) $(WINLIBS)
-WLIBS = $(PNGLIB) $(ZLIB)
-
-CC = cl
-LD = link
-RM = del
-CFLAGS = -nologo -O -W3 $(INCS) $(cvars)
-# [note that -W3 is an MSVC-specific compilation flag ("all warnings on")]
-# [see %devstudio%\vc\include\win32.mak for cvars macro definition]
-O = .obj
-E = .exe
-
-RLDFLAGS = -nologo -subsystem:windows
-WLDFLAGS = -nologo
-
-RPNG  = rpng-win
-RPNG2 = rpng2-win
-WPNG  = wpng
-
-ROBJS  = $(RPNG)$(O) readpng$(O)
-ROBJS2 = $(RPNG2)$(O) readpng2$(O)
-WOBJS  = $(WPNG)$(O) writepng$(O)
-
-EXES = $(RPNG)$(E) $(RPNG2)$(E) $(WPNG)$(E)
-
-
-# implicit make rules -------------------------------------------------------
-
-.c$(O):
-	$(CC) -c $(CFLAGS) $<
-
-
-# dependencies --------------------------------------------------------------
-
-all:  $(EXES)
-
-$(RPNG)$(E): $(ROBJS)
-	$(LD) $(RLDFLAGS) -out:$@ $(ROBJS) $(RLIBS)
-
-$(RPNG2)$(E): $(ROBJS2)
-	$(LD) $(RLDFLAGS) -out:$@ $(ROBJS2) $(RLIBS)
-
-$(WPNG)$(E): $(WOBJS)
-	$(LD) $(WLDFLAGS) -out:$@ $(WOBJS) $(WLIBS)
-
-$(RPNG)$(O):	$(RPNG).c readpng.h
-$(RPNG2)$(O):	$(RPNG2).c readpng2.h
-$(WPNG)$(O):	$(WPNG).c writepng.h
-
-readpng$(O):	readpng.c readpng.h
-readpng2$(O):	readpng2.c readpng2.h
-writepng$(O):	writepng.c writepng.h
-
-
-# maintenance ---------------------------------------------------------------
-
-clean:
-#	ideally we could just do this:
-#	$(RM) $(EXES) $(ROBJS) $(ROBJS2) $(WOBJS)
-#	...but the Windows "DEL" command is none too bright, so:
-	$(RM) r*$(E)
-	$(RM) w*$(E)
-	$(RM) r*$(O)
-	$(RM) w*$(O)
diff --git a/contrib/gregbook/README b/contrib/gregbook/README
deleted file mode 100644
index cb6e525..0000000
--- a/contrib/gregbook/README
+++ /dev/null
@@ -1,186 +0,0 @@
-                     ===========================
-                      PNG: The Definitive Guide
-                     ===========================
-
-                             Source Code
-
-Chapters 13, 14 and 15 of "PNG: The Definitive Guide" discuss three free,
-cross-platform demo programs that show how to use the libpng reference
-library:  rpng, rpng2 and wpng.  rpng and rpng2 are viewers; the first is
-a very simple example that that shows how a standard file-viewer might use
-libpng, while the second is designed to process streaming data and shows
-how a web browser might be written.  wpng is a simple command-line program
-that reads binary PGM and PPM files (the ``raw'' grayscale and RGB subsets
-of PBMPLUS/NetPBM) and converts them to PNG.
-
-The source code for all three demo programs currently compiles under
-Unix, OpenVMS, and 32-bit Windows.  (Special thanks to Martin Zinser,
-zinser@decus.de, for making the necessary changes for OpenVMS and for
-providing an appropriate build script.)  Build instructions can be found
-below.
-
-Files:
-
-   README             this file
-   LICENSE            terms of distribution and reuse (BSD-like or GNU GPL)
-   COPYING            GNU General Public License (GPL)
-
-   Makefile.unx       Unix makefile
-   Makefile.w32       Windows (MSVC) makefile
-   makevms.com        OpenVMS build script
-
-   rpng-win.c         Windows front end for the basic viewer
-   rpng-x.c           X Window System (Unix, OpenVMS) front end
-   readpng.c          generic back end for the basic viewer
-   readpng.h          header file for the basic viewer
-
-   rpng2-win.c        Windows front end for the progressive viewer
-   rpng2-x.c          X front end for the progressive viewer
-   readpng2.c         generic back end for the progressive viewer
-   readpng2.h         header file for the progressive viewer
-
-   wpng.c             generic (text) front end for the converter
-   writepng.c         generic back end for the converter
-   writepng.h         header file for the converter
-
-   toucan.png         transparent PNG for testing (by Stefan Schneider)
-
-Note that, although the programs are designed to be functional, their
-primary purpose is to illustrate how to use libpng to add PNG support to
-other programs.  As such, their user interfaces are crude and definitely
-are not intended for everyday use.
-
-Please see http://www.libpng.org/pub/png/pngbook.html for further infor-
-mation and links to the latest version of the source code, and Chapters
-13-15 of the book for detailed discussion of the three programs.
-
-Greg Roelofs
-http://pobox.com/~newt/greg_contact.html
-16 March 2008
-
-
-BUILD INSTRUCTIONS
-
- - Prerequisites (in order of compilation):
-
-      - zlib		http://zlib.net/
-      - libpng		http://www.libpng.org/pub/png/libpng.html
-      - pngbook		http://www.libpng.org/pub/png/book/sources.html
-
-     The pngbook demo programs are explicitly designed to demonstrate proper
-     coding techniques for using the libpng reference library.  As a result,
-     you need to download and build both zlib (on which libpng depends) and
-     libpng.  A common build setup is to place the zlib, libpng and pngbook
-     subdirectory trees ("folders") in the same parent directory.  Then the
-     libpng build can refer to files in ../zlib (or ..\zlib or [-.zlib]),
-     and similarly for the pngbook build.
-
-     Note that all three packages are designed to be built from a command
-     line by default; those who wish to use a graphical or other integrated
-     development environments are on their own.
-
-
- - Unix:
-
-     Unpack the latest pngbook sources (which should correspond to this
-     README file) into a directory and change into that directory.
-
-     Copy Makefile.unx to Makefile and edit the PNG* and Z* variables
-     appropriately (possibly also the X* variables if necessary).
-
-     make
-
-     There is no "install" target, so copy the three executables somewhere
-     in your path or run them from the current directory.  All three will
-     print a basic usage screen when run without any command-line arguments;
-     see the book for more details.
-
-
- - Windows:
-
-     Unpack the latest pngbook sources (which should correspond to this
-     README file) into a folder, open a "DOS shell" or "command prompt"
-     or equivalent command-line window, and cd into the folder where you
-     unpacked the source code.
-
-     For MSVC, set up the necessary environment variables by invoking
- 
-        %devstudio%\vc\bin\vcvars32.bat
-
-     where where %devstudio% is the installation directory for MSVC /
-     DevStudio.  If you get "environment out of space" errors under 95/98,
-     create a desktop shortcut with "c:\windows\command.com /e:4096" as
-     the program command line and set the working directory to the pngbook
-     directory.  Then double-click to open the new DOS-prompt window with
-     a bigger environment and retry the commands above.
-
-     Copy Makefile.w32 to Makefile and edit the PNGPATH and ZPATH variables
-     appropriately (possibly also the "INC" and "LIB" variables if needed).
-     Note that the names of the dynamic and static libpng and zlib libraries
-     used in the makefile may change in later releases of the libraries.
-     Also note that, as of libpng version 1.0.5, MSVC DLL builds do not work.
-     This makefile therefore builds statically linked executables, but if
-     the DLL problems ever get fixed, uncommenting the appropriate PNGLIB
-     and ZLIB lines will build dynamically linked executables instead.
-
-     Do the build by typing
-
-        nmake
-
-     The result should be three executables:  rpng-win.exe, rpng2-win.exe,
-     and wpng.exe.  Copy them somewhere in your PATH or run them from the
-     current folder.  Like the Unix versions, the two windowed programs
-     (rpng and rpng2) now display a usage screen in a console window when
-     invoked without command-line arguments; this is new behavior as of
-     the June 2001 release.  Note that the programs use the Unix-style "-"
-     character to specify options, instead of the more common DOS/Windows
-     "/" character.  (For example:  "rpng2-win -bgpat 4 foo.png", not
-     "rpng2-win /bgpat 4 foo.png")
-
-
- - OpenVMS:
-
-     Unpack the pngbook sources into a subdirectory and change into that
-     subdirectory.
-
-     Edit makevms.com appropriately, specifically the zpath and pngpath
-     variables.
-
-     @makevms
-
-     To run the programs, they probably first need to be set up as "foreign
-     symbols," with "disk" and "dir" set appropriately:
-
-     $ rpng  == "$disk:[dir]rpng-x.exe"
-     $ rpng2 == "$disk:[dir]rpng2-x.exe"
-     $ wpng  == "$disk:[dir]wpng.exe"
-
-     All three will print a basic usage screen when run without any command-
-     line arguments; see the book for more details.  Note that the options
-     style is Unix-like, i.e., preceded by "-" rather than "/".
-
-
-RUNNING THE PROGRAMS:  (VERY) BRIEF INTRO
-
-     rpng is a simple PNG viewer that can display transparent PNGs with a
-     specified background color; for example,
-
-	rpng -bgcolor #ff0000 toucan.png
-
-     would display the image with a red background.  rpng2 is a progressive
-     viewer that simulates a web browser in some respects; it can display
-     images against either a background color or a dynamically generated
-     background image.  For example:
-
-	rpng2 -bgpat 16 toucan.png
-
-     wpng is a purely command-line image converter from binary PBMPLUS/NetPBM
-     format (.pgm or .ppm) to PNG; for example,
-
-	wpng -time < toucan-notrans.ppm > toucan-notrans.png
-
-     would convert the specified PPM file (using redirection) to PNG, auto-
-     matically setting the PNG modification-time chunk.
-
-     All options can be abbreviated to the shortest unique value; for example,
-     "-bgc" for -bgcolor (versus "-bgp" for -bgpat), or "-g" for -gamma.
diff --git a/contrib/gregbook/makevms.com b/contrib/gregbook/makevms.com
deleted file mode 100644
index bd37dc0..0000000
--- a/contrib/gregbook/makevms.com
+++ /dev/null
@@ -1,132 +0,0 @@
-$!------------------------------------------------------------------------------
-$! make "PNG: The Definitive Guide" demo programs (for X) under OpenVMS
-$!
-$! Script created by Martin Zinser for libpng; modified by Greg Roelofs
-$! for standalone pngbook source distribution.
-$!
-$!
-$!    Set locations where zlib and libpng sources live.
-$!
-$ zpath   = ""
-$ pngpath = ""
-$!
-$ if f$search("[---.zlib]zlib.h").nes."" then zpath = "[---.zlib]"
-$ if f$search("[--]png.h").nes."" then pngpath = "[--]"
-$!
-$ if f$search("[-.zlib]zlib.h").nes."" then zpath = "[-.zlib]"
-$ if f$search("[-.libpng]png.h").nes."" then pngpath = "[-.libpng]"
-$!
-$ if zpath .eqs. ""
-$ then
-$   write sys$output "zlib include not found. Exiting..."
-$   exit 2
-$ endif 
-$!
-$ if pngpath .eqs. ""
-$ then
-$   write sys$output "libpng include not found. Exiting..."
-$   exit 2
-$ endif 
-$!
-$!    Look for the compiler used.
-$!
-$ ccopt="/include=(''zpath',''pngpath')"
-$ if f$getsyi("HW_MODEL").ge.1024
-$ then
-$  ccopt = "/prefix=all"+ccopt
-$  comp  = "__decc__=1"
-$  if f$trnlnm("SYS").eqs."" then define sys sys$library:
-$ else
-$  if f$search("SYS$SYSTEM:DECC$COMPILER.EXE").eqs.""
-$   then
-$    if f$trnlnm("SYS").eqs."" then define sys sys$library:
-$    if f$search("SYS$SYSTEM:VAXC.EXE").eqs.""
-$     then
-$      comp  = "__gcc__=1"
-$      CC :== GCC
-$     else
-$      comp = "__vaxc__=1"
-$     endif
-$   else
-$    if f$trnlnm("SYS").eqs."" then define sys decc$library_include:
-$    ccopt = "/decc/prefix=all"+ccopt
-$    comp  = "__decc__=1"
-$  endif
-$ endif
-$ open/write lopt lib.opt
-$ write lopt "''pngpath'libpng.olb/lib"
-$ write lopt "''zpath'libz.olb/lib"
-$ close lopt
-$ open/write xopt x11.opt
-$ write xopt "sys$library:decw$xlibshr.exe/share"
-$ close xopt
-$!
-$!    Build 'em.
-$!
-$ write sys$output "Compiling PNG book programs ..."
-$   CALL MAKE readpng.OBJ "cc ''CCOPT' readpng" -
-	readpng.c readpng.h
-$   CALL MAKE readpng2.OBJ "cc ''CCOPT' readpng2" -
-	readpng2.c readpng2.h
-$   CALL MAKE writepng.OBJ "cc ''CCOPT' writepng" -
-	writepng.c writepng.h
-$   write sys$output "Building rpng-x..."
-$   CALL MAKE rpng-x.OBJ "cc ''CCOPT' rpng-x" -
-	rpng-x.c readpng.h
-$   call make rpng-x.exe -
-	"LINK rpng-x,readpng,lib.opt/opt,x11.opt/opt" -
-	rpng-x.obj readpng.obj
-$   write sys$output "Building rpng2-x..."
-$   CALL MAKE rpng2-x.OBJ "cc ''CCOPT' rpng2-x" -
-	rpng2-x.c readpng2.h
-$   call make rpng2-x.exe -
-	"LINK rpng2-x,readpng2,lib.opt/opt,x11.opt/opt" -
-	rpng2-x.obj readpng2.obj
-$   write sys$output "Building wpng..."
-$   CALL MAKE wpng.OBJ "cc ''CCOPT' wpng" -
-	wpng.c writepng.h
-$   call make wpng.exe -
-	"LINK wpng,writepng,lib.opt/opt" -
-	wpng.obj writepng.obj
-$ exit
-$!
-$!
-$MAKE: SUBROUTINE   !SUBROUTINE TO CHECK DEPENDENCIES
-$ V = 'F$Verify(0)
-$! P1 = What we are trying to make
-$! P2 = Command to make it
-$! P3 - P8  What it depends on
-$
-$ If F$Search(P1) .Eqs. "" Then Goto Makeit
-$ Time = F$CvTime(F$File(P1,"RDT"))
-$arg=3
-$Loop:
-$       Argument = P'arg
-$       If Argument .Eqs. "" Then Goto Exit
-$       El=0
-$Loop2:
-$       File = F$Element(El," ",Argument)
-$       If File .Eqs. " " Then Goto Endl
-$       AFile = ""
-$Loop3:
-$       OFile = AFile
-$       AFile = F$Search(File)
-$       If AFile .Eqs. "" .Or. AFile .Eqs. OFile Then Goto NextEl
-$       If F$CvTime(F$File(AFile,"RDT")) .Ges. Time Then Goto Makeit
-$       Goto Loop3
-$NextEL:
-$       El = El + 1
-$       Goto Loop2
-$EndL:
-$ arg=arg+1
-$ If arg .Le. 8 Then Goto Loop
-$ Goto Exit
-$
-$Makeit:
-$ VV=F$VERIFY(0)
-$ write sys$output P2
-$ 'P2
-$ VV='F$Verify(VV)
-$Exit:
-$ If V Then Set Verify
-$ENDSUBROUTINE
diff --git a/contrib/gregbook/readpng.c b/contrib/gregbook/readpng.c
deleted file mode 100644
index d87f6c7..0000000
--- a/contrib/gregbook/readpng.c
+++ /dev/null
@@ -1,304 +0,0 @@
-/*---------------------------------------------------------------------------
-
-   rpng - simple PNG display program                              readpng.c
-
-  ---------------------------------------------------------------------------
-
-      Copyright (c) 1998-2007 Greg Roelofs.  All rights reserved.
-
-      This software is provided "as is," without warranty of any kind,
-      express or implied.  In no event shall the author or contributors
-      be held liable for any damages arising in any way from the use of
-      this software.
-
-      The contents of this file are DUAL-LICENSED.  You may modify and/or
-      redistribute this software according to the terms of one of the
-      following two licenses (at your option):
-
-
-      LICENSE 1 ("BSD-like with advertising clause"):
-
-      Permission is granted to anyone to use this software for any purpose,
-      including commercial applications, and to alter it and redistribute
-      it freely, subject to the following restrictions:
-
-      1. Redistributions of source code must retain the above copyright
-         notice, disclaimer, and this list of conditions.
-      2. Redistributions in binary form must reproduce the above copyright
-         notice, disclaimer, and this list of conditions in the documenta-
-         tion and/or other materials provided with the distribution.
-      3. All advertising materials mentioning features or use of this
-         software must display the following acknowledgment:
-
-            This product includes software developed by Greg Roelofs
-            and contributors for the book, "PNG: The Definitive Guide,"
-            published by O'Reilly and Associates.
-
-
-      LICENSE 2 (GNU GPL v2 or later):
-
-      This program is free software; you can redistribute it and/or modify
-      it under the terms of the GNU General Public License as published by
-      the Free Software Foundation; either version 2 of the License, or
-      (at your option) any later version.
-
-      This program is distributed in the hope that it will be useful,
-      but WITHOUT ANY WARRANTY; without even the implied warranty of
-      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-      GNU General Public License for more details.
-
-      You should have received a copy of the GNU General Public License
-      along with this program; if not, write to the Free Software Foundation,
-      Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
-
-  ---------------------------------------------------------------------------*/
-
-#include <stdio.h>
-#include <stdlib.h>
-
-#include "png.h"        /* libpng header; includes zlib.h */
-#include "readpng.h"    /* typedefs, common macros, public prototypes */
-
-/* future versions of libpng will provide this macro: */
-#ifndef png_jmpbuf
-#  define png_jmpbuf(png_ptr)   ((png_ptr)->jmpbuf)
-#endif
-
-
-static png_structp png_ptr = NULL;
-static png_infop info_ptr = NULL;
-
-png_uint_32  width, height;
-int  bit_depth, color_type;
-uch  *image_data = NULL;
-
-
-void readpng_version_info(void)
-{
-    fprintf(stderr, "   Compiled with libpng %s; using libpng %s.\n",
-      PNG_LIBPNG_VER_STRING, png_libpng_ver);
-    fprintf(stderr, "   Compiled with zlib %s; using zlib %s.\n",
-      ZLIB_VERSION, zlib_version);
-}
-
-
-/* return value = 0 for success, 1 for bad sig, 2 for bad IHDR, 4 for no mem */
-
-int readpng_init(FILE *infile, ulg *pWidth, ulg *pHeight)
-{
-    uch sig[8];
-
-
-    /* first do a quick check that the file really is a PNG image; could
-     * have used slightly more general png_sig_cmp() function instead */
-
-    fread(sig, 1, 8, infile);
-    if (!png_check_sig(sig, 8))
-        return 1;   /* bad signature */
-
-
-    /* could pass pointers to user-defined error handlers instead of NULLs: */
-
-    png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
-    if (!png_ptr)
-        return 4;   /* out of memory */
-
-    info_ptr = png_create_info_struct(png_ptr);
-    if (!info_ptr) {
-        png_destroy_read_struct(&png_ptr, NULL, NULL);
-        return 4;   /* out of memory */
-    }
-
-
-    /* we could create a second info struct here (end_info), but it's only
-     * useful if we want to keep pre- and post-IDAT chunk info separated
-     * (mainly for PNG-aware image editors and converters) */
-
-
-    /* setjmp() must be called in every function that calls a PNG-reading
-     * libpng function */
-
-    if (setjmp(png_jmpbuf(png_ptr))) {
-        png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
-        return 2;
-    }
-
-
-    png_init_io(png_ptr, infile);
-    png_set_sig_bytes(png_ptr, 8);  /* we already read the 8 signature bytes */
-
-    png_read_info(png_ptr, info_ptr);  /* read all PNG info up to image data */
-
-
-    /* alternatively, could make separate calls to png_get_image_width(),
-     * etc., but want bit_depth and color_type for later [don't care about
-     * compression_type and filter_type => NULLs] */
-
-    png_get_IHDR(png_ptr, info_ptr, &width, &height, &bit_depth, &color_type,
-      NULL, NULL, NULL);
-    *pWidth = width;
-    *pHeight = height;
-
-
-    /* OK, that's all we need for now; return happy */
-
-    return 0;
-}
-
-
-
-
-/* returns 0 if succeeds, 1 if fails due to no bKGD chunk, 2 if libpng error;
- * scales values to 8-bit if necessary */
-
-int readpng_get_bgcolor(uch *red, uch *green, uch *blue)
-{
-    png_color_16p pBackground;
-
-
-    /* setjmp() must be called in every function that calls a PNG-reading
-     * libpng function */
-
-    if (setjmp(png_jmpbuf(png_ptr))) {
-        png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
-        return 2;
-    }
-
-
-    if (!png_get_valid(png_ptr, info_ptr, PNG_INFO_bKGD))
-        return 1;
-
-    /* it is not obvious from the libpng documentation, but this function
-     * takes a pointer to a pointer, and it always returns valid red, green
-     * and blue values, regardless of color_type: */
-
-    png_get_bKGD(png_ptr, info_ptr, &pBackground);
-
-
-    /* however, it always returns the raw bKGD data, regardless of any
-     * bit-depth transformations, so check depth and adjust if necessary */
-
-    if (bit_depth == 16) {
-        *red   = pBackground->red   >> 8;
-        *green = pBackground->green >> 8;
-        *blue  = pBackground->blue  >> 8;
-    } else if (color_type == PNG_COLOR_TYPE_GRAY && bit_depth < 8) {
-        if (bit_depth == 1)
-            *red = *green = *blue = pBackground->gray? 255 : 0;
-        else if (bit_depth == 2)
-            *red = *green = *blue = (255/3) * pBackground->gray;
-        else /* bit_depth == 4 */
-            *red = *green = *blue = (255/15) * pBackground->gray;
-    } else {
-        *red   = (uch)pBackground->red;
-        *green = (uch)pBackground->green;
-        *blue  = (uch)pBackground->blue;
-    }
-
-    return 0;
-}
-
-
-
-
-/* display_exponent == LUT_exponent * CRT_exponent */
-
-uch *readpng_get_image(double display_exponent, int *pChannels, ulg *pRowbytes)
-{
-    double  gamma;
-    png_uint_32  i, rowbytes;
-    png_bytepp  row_pointers = NULL;
-
-
-    /* setjmp() must be called in every function that calls a PNG-reading
-     * libpng function */
-
-    if (setjmp(png_jmpbuf(png_ptr))) {
-        png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
-        return NULL;
-    }
-
-
-    /* expand palette images to RGB, low-bit-depth grayscale images to 8 bits,
-     * transparency chunks to full alpha channel; strip 16-bit-per-sample
-     * images to 8 bits per sample; and convert grayscale to RGB[A] */
-
-    if (color_type == PNG_COLOR_TYPE_PALETTE)
-        png_set_expand(png_ptr);
-    if (color_type == PNG_COLOR_TYPE_GRAY && bit_depth < 8)
-        png_set_expand(png_ptr);
-    if (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS))
-        png_set_expand(png_ptr);
-    if (bit_depth == 16)
-        png_set_strip_16(png_ptr);
-    if (color_type == PNG_COLOR_TYPE_GRAY ||
-        color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
-        png_set_gray_to_rgb(png_ptr);
-
-
-    /* unlike the example in the libpng documentation, we have *no* idea where
-     * this file may have come from--so if it doesn't have a file gamma, don't
-     * do any correction ("do no harm") */
-
-    if (png_get_gAMA(png_ptr, info_ptr, &gamma))
-        png_set_gamma(png_ptr, display_exponent, gamma);
-
-
-    /* all transformations have been registered; now update info_ptr data,
-     * get rowbytes and channels, and allocate image memory */
-
-    png_read_update_info(png_ptr, info_ptr);
-
-    *pRowbytes = rowbytes = png_get_rowbytes(png_ptr, info_ptr);
-    *pChannels = (int)png_get_channels(png_ptr, info_ptr);
-
-    if ((image_data = (uch *)malloc(rowbytes*height)) == NULL) {
-        png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
-        return NULL;
-    }
-    if ((row_pointers = (png_bytepp)malloc(height*sizeof(png_bytep))) == NULL) {
-        png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
-        free(image_data);
-        image_data = NULL;
-        return NULL;
-    }
-
-    Trace((stderr, "readpng_get_image:  channels = %d, rowbytes = %ld, height = %ld\n", *pChannels, rowbytes, height));
-
-
-    /* set the individual row_pointers to point at the correct offsets */
-
-    for (i = 0;  i < height;  ++i)
-        row_pointers[i] = image_data + i*rowbytes;
-
-
-    /* now we can go ahead and just read the whole image */
-
-    png_read_image(png_ptr, row_pointers);
-
-
-    /* and we're done!  (png_read_end() can be omitted if no processing of
-     * post-IDAT text/time/etc. is desired) */
-
-    free(row_pointers);
-    row_pointers = NULL;
-
-    png_read_end(png_ptr, NULL);
-
-    return image_data;
-}
-
-
-void readpng_cleanup(int free_image_data)
-{
-    if (free_image_data && image_data) {
-        free(image_data);
-        image_data = NULL;
-    }
-
-    if (png_ptr && info_ptr) {
-        png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
-        png_ptr = NULL;
-        info_ptr = NULL;
-    }
-}
diff --git a/contrib/gregbook/readpng.h b/contrib/gregbook/readpng.h
deleted file mode 100644
index fad9fe3..0000000
--- a/contrib/gregbook/readpng.h
+++ /dev/null
@@ -1,88 +0,0 @@
-/*---------------------------------------------------------------------------
-
-   rpng - simple PNG display program                              readpng.h
-
-  ---------------------------------------------------------------------------
-
-      Copyright (c) 1998-2007 Greg Roelofs.  All rights reserved.
-
-      This software is provided "as is," without warranty of any kind,
-      express or implied.  In no event shall the author or contributors
-      be held liable for any damages arising in any way from the use of
-      this software.
-
-      The contents of this file are DUAL-LICENSED.  You may modify and/or
-      redistribute this software according to the terms of one of the
-      following two licenses (at your option):
-
-
-      LICENSE 1 ("BSD-like with advertising clause"):
-
-      Permission is granted to anyone to use this software for any purpose,
-      including commercial applications, and to alter it and redistribute
-      it freely, subject to the following restrictions:
-
-      1. Redistributions of source code must retain the above copyright
-         notice, disclaimer, and this list of conditions.
-      2. Redistributions in binary form must reproduce the above copyright
-         notice, disclaimer, and this list of conditions in the documenta-
-         tion and/or other materials provided with the distribution.
-      3. All advertising materials mentioning features or use of this
-         software must display the following acknowledgment:
-
-            This product includes software developed by Greg Roelofs
-            and contributors for the book, "PNG: The Definitive Guide,"
-            published by O'Reilly and Associates.
-
-
-      LICENSE 2 (GNU GPL v2 or later):
-
-      This program is free software; you can redistribute it and/or modify
-      it under the terms of the GNU General Public License as published by
-      the Free Software Foundation; either version 2 of the License, or
-      (at your option) any later version.
-
-      This program is distributed in the hope that it will be useful,
-      but WITHOUT ANY WARRANTY; without even the implied warranty of
-      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-      GNU General Public License for more details.
-
-      You should have received a copy of the GNU General Public License
-      along with this program; if not, write to the Free Software Foundation,
-      Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
-
-  ---------------------------------------------------------------------------*/
-
-#ifndef TRUE
-#  define TRUE 1
-#  define FALSE 0
-#endif
-
-#ifndef MAX
-#  define MAX(a,b)  ((a) > (b)? (a) : (b))
-#  define MIN(a,b)  ((a) < (b)? (a) : (b))
-#endif
-
-#ifdef DEBUG
-#  define Trace(x)  {fprintf x ; fflush(stderr); fflush(stdout);}
-#else
-#  define Trace(x)  ;
-#endif
-
-typedef unsigned char   uch;
-typedef unsigned short  ush;
-typedef unsigned long   ulg;
-
-
-/* prototypes for public functions in readpng.c */
-
-void readpng_version_info(void);
-
-int readpng_init(FILE *infile, ulg *pWidth, ulg *pHeight);
-
-int readpng_get_bgcolor(uch *bg_red, uch *bg_green, uch *bg_blue);
-
-uch *readpng_get_image(double display_exponent, int *pChannels,
-                       ulg *pRowbytes);
-
-void readpng_cleanup(int free_image_data);
diff --git a/contrib/gregbook/readpng2.c b/contrib/gregbook/readpng2.c
deleted file mode 100644
index 9215042..0000000
--- a/contrib/gregbook/readpng2.c
+++ /dev/null
@@ -1,645 +0,0 @@
-/*---------------------------------------------------------------------------
-
-   rpng2 - progressive-model PNG display program                 readpng2.c
-
-  ---------------------------------------------------------------------------
-
-      Copyright (c) 1998-2007 Greg Roelofs.  All rights reserved.
-
-      This software is provided "as is," without warranty of any kind,
-      express or implied.  In no event shall the author or contributors
-      be held liable for any damages arising in any way from the use of
-      this software.
-
-      The contents of this file are DUAL-LICENSED.  You may modify and/or
-      redistribute this software according to the terms of one of the
-      following two licenses (at your option):
-
-
-      LICENSE 1 ("BSD-like with advertising clause"):
-
-      Permission is granted to anyone to use this software for any purpose,
-      including commercial applications, and to alter it and redistribute
-      it freely, subject to the following restrictions:
-
-      1. Redistributions of source code must retain the above copyright
-         notice, disclaimer, and this list of conditions.
-      2. Redistributions in binary form must reproduce the above copyright
-         notice, disclaimer, and this list of conditions in the documenta-
-         tion and/or other materials provided with the distribution.
-      3. All advertising materials mentioning features or use of this
-         software must display the following acknowledgment:
-
-            This product includes software developed by Greg Roelofs
-            and contributors for the book, "PNG: The Definitive Guide,"
-            published by O'Reilly and Associates.
-
-
-      LICENSE 2 (GNU GPL v2 or later):
-
-      This program is free software; you can redistribute it and/or modify
-      it under the terms of the GNU General Public License as published by
-      the Free Software Foundation; either version 2 of the License, or
-      (at your option) any later version.
-
-      This program is distributed in the hope that it will be useful,
-      but WITHOUT ANY WARRANTY; without even the implied warranty of
-      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-      GNU General Public License for more details.
-
-      You should have received a copy of the GNU General Public License
-      along with this program; if not, write to the Free Software Foundation,
-      Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
-
-  ---------------------------------------------------------------------------*/
-
-
-#include <stdlib.h>     /* for exit() prototype */
-
-#include "png.h"        /* libpng header; includes zlib.h and setjmp.h */
-#include "readpng2.h"   /* typedefs, common macros, public prototypes */
-
-
-/* local prototypes */
-
-static void readpng2_info_callback(png_structp png_ptr, png_infop info_ptr);
-static void readpng2_row_callback(png_structp png_ptr, png_bytep new_row,
-                                 png_uint_32 row_num, int pass);
-static void readpng2_end_callback(png_structp png_ptr, png_infop info_ptr);
-static void readpng2_error_handler(png_structp png_ptr, png_const_charp msg);
-
-
-
-
-void readpng2_version_info(void)
-{
-#if defined(PNG_ASSEMBLER_CODE_SUPPORTED) && \
-    (defined(__i386__) || defined(_M_IX86) || defined(__x86_64__)) && \
-    defined(PNG_LIBPNG_VER) && (PNG_LIBPNG_VER >= 10200)
-    /*
-     * WARNING:  This preprocessor approach means that the following code
-     *           cannot be used with a libpng DLL older than 1.2.0--the
-     *           compiled-in symbols for the new functions will not exist.
-     *           (Could use dlopen() and dlsym() on Unix and corresponding
-     *           calls for Windows, but not portable...)
-     */
-    {
-        int mmxsupport = png_mmx_support();
-        if (mmxsupport < 0)
-            fprintf(stderr, "   Compiled with libpng %s; using libpng %s "
-              "without MMX support.\n", PNG_LIBPNG_VER_STRING, png_libpng_ver);
-        else {
-            int compilerID;
-            png_uint_32 mmx_mask = png_get_mmx_flagmask(
-              PNG_SELECT_READ | PNG_SELECT_WRITE, &compilerID);
-
-            fprintf(stderr, "   Compiled with libpng %s; using libpng %s "
-              "with MMX support\n   (%s version).", PNG_LIBPNG_VER_STRING,
-              png_libpng_ver, compilerID == 1? "MSVC++" :
-              (compilerID == 2? "GNU C" : "unknown"));
-            fprintf(stderr, "  Processor (x86%s) %s MMX instructions.\n",
-#if defined(__x86_64__)
-              "_64",
-#else
-              "",
-#endif
-              mmxsupport? "supports" : "does not support");
-            if (mmxsupport > 0) {
-                int num_optims = 0;
-
-                fprintf(stderr,
-                  "      Potential MMX optimizations supported by libpng:\n");
-                if (mmx_mask & PNG_ASM_FLAG_MMX_READ_FILTER_SUB)
-                    ++num_optims;
-                if (mmx_mask & PNG_ASM_FLAG_MMX_READ_FILTER_UP)
-                    ++num_optims;
-                if (mmx_mask & PNG_ASM_FLAG_MMX_READ_FILTER_AVG)
-                    ++num_optims;
-                if (mmx_mask & PNG_ASM_FLAG_MMX_READ_FILTER_PAETH)
-                    ++num_optims;
-                if (num_optims)
-                    fprintf(stderr,
-                      "         decoding %s row filters (reading)\n",
-                      (num_optims == 4)? "all non-trivial" : "some");
-                if (mmx_mask & PNG_ASM_FLAG_MMX_READ_COMBINE_ROW) {
-                    fprintf(stderr, "         combining rows (reading)\n");
-                    ++num_optims;
-                }
-                if (mmx_mask & PNG_ASM_FLAG_MMX_READ_INTERLACE) {
-                    fprintf(stderr,
-                      "         expanding interlacing (reading)\n");
-                    ++num_optims;
-                }
-                mmx_mask &= ~( PNG_ASM_FLAG_MMX_READ_COMBINE_ROW  \
-                             | PNG_ASM_FLAG_MMX_READ_INTERLACE    \
-                             | PNG_ASM_FLAG_MMX_READ_FILTER_SUB   \
-                             | PNG_ASM_FLAG_MMX_READ_FILTER_UP    \
-                             | PNG_ASM_FLAG_MMX_READ_FILTER_AVG   \
-                             | PNG_ASM_FLAG_MMX_READ_FILTER_PAETH );
-                if (mmx_mask) {
-                    fprintf(stderr, "         other (unknown)\n");
-                    ++num_optims;
-                }
-                if (num_optims == 0)
-                    fprintf(stderr, "         (none)\n");
-            }
-        }
-    }
-#else
-    fprintf(stderr, "   Compiled with libpng %s; using libpng %s "
-      "without MMX support.\n", PNG_LIBPNG_VER_STRING, png_libpng_ver);
-#endif
-
-    fprintf(stderr, "   Compiled with zlib %s; using zlib %s.\n",
-      ZLIB_VERSION, zlib_version);
-}
-
-
-
-
-int readpng2_check_sig(uch *sig, int num)
-{
-    return png_check_sig(sig, num);
-}
-
-
-
-
-/* returns 0 for success, 2 for libpng problem, 4 for out of memory */
-
-int readpng2_init(mainprog_info *mainprog_ptr)
-{
-    png_structp  png_ptr;       /* note:  temporary variables! */
-    png_infop  info_ptr;
-
-
-    /* could also replace libpng warning-handler (final NULL), but no need: */
-
-    png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, mainprog_ptr,
-      readpng2_error_handler, NULL);
-    if (!png_ptr)
-        return 4;   /* out of memory */
-
-    info_ptr = png_create_info_struct(png_ptr);
-    if (!info_ptr) {
-        png_destroy_read_struct(&png_ptr, NULL, NULL);
-        return 4;   /* out of memory */
-    }
-
-
-    /* we could create a second info struct here (end_info), but it's only
-     * useful if we want to keep pre- and post-IDAT chunk info separated
-     * (mainly for PNG-aware image editors and converters) */
-
-
-    /* setjmp() must be called in every function that calls a PNG-reading
-     * libpng function, unless an alternate error handler was installed--
-     * but compatible error handlers must either use longjmp() themselves
-     * (as in this program) or exit immediately, so here we are: */
-
-    if (setjmp(mainprog_ptr->jmpbuf)) {
-        png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
-        return 2;
-    }
-
-
-#ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
-    /* prepare the reader to ignore all recognized chunks whose data won't be
-     * used, i.e., all chunks recognized by libpng except for IHDR, PLTE, IDAT,
-     * IEND, tRNS, bKGD, gAMA, and sRGB (small performance improvement) */
-    {
-        /* These byte strings were copied from png.h.  If a future libpng
-         * version recognizes more chunks, add them to this list.  If a
-         * future version of readpng2.c recognizes more chunks, delete them
-         * from this list. */
-        static const png_byte chunks_to_ignore[] = {
-             99,  72,  82,  77, '\0',  /* cHRM */
-            104,  73,  83,  84, '\0',  /* hIST */
-            105,  67,  67,  80, '\0',  /* iCCP */
-            105,  84,  88, 116, '\0',  /* iTXt */
-            111,  70,  70, 115, '\0',  /* oFFs */
-            112,  67,  65,  76, '\0',  /* pCAL */
-            112,  72,  89, 115, '\0',  /* pHYs */
-            115,  66,  73,  84, '\0',  /* sBIT */
-            115,  67,  65,  76, '\0',  /* sCAL */
-            115,  80,  76,  84, '\0',  /* sPLT */
-            115,  84,  69,  82, '\0',  /* sTER */
-            116,  69,  88, 116, '\0',  /* tEXt */
-            116,  73,  77,  69, '\0',  /* tIME */
-            122,  84,  88, 116, '\0'   /* zTXt */
-        };
-
-        png_set_keep_unknown_chunks(png_ptr, 1 /* PNG_HANDLE_CHUNK_NEVER */,
-          chunks_to_ignore, sizeof(chunks_to_ignore)/5);
-    }
-#endif /* PNG_UNKNOWN_CHUNKS_SUPPORTED */
-
-
-    /* instead of doing png_init_io() here, now we set up our callback
-     * functions for progressive decoding */
-
-    png_set_progressive_read_fn(png_ptr, mainprog_ptr,
-      readpng2_info_callback, readpng2_row_callback, readpng2_end_callback);
-
-
-    /*
-     * may as well enable or disable MMX routines here, if supported;
-     *
-     * to enable all:  mask = png_get_mmx_flagmask (
-     *                   PNG_SELECT_READ | PNG_SELECT_WRITE, &compilerID);
-     *                 flags = png_get_asm_flags (png_ptr);
-     *                 flags |= mask;
-     *                 png_set_asm_flags (png_ptr, flags);
-     *
-     * to disable all:  mask = png_get_mmx_flagmask (
-     *                   PNG_SELECT_READ | PNG_SELECT_WRITE, &compilerID);
-     *                  flags = png_get_asm_flags (png_ptr);
-     *                  flags &= ~mask;
-     *                  png_set_asm_flags (png_ptr, flags);
-     */
-
-#if (defined(__i386__) || defined(_M_IX86) || defined(__x86_64__)) && \
-    defined(PNG_LIBPNG_VER) && (PNG_LIBPNG_VER >= 10200)
-    /*
-     * WARNING:  This preprocessor approach means that the following code
-     *           cannot be used with a libpng DLL older than 1.2.0--the
-     *           compiled-in symbols for the new functions will not exist.
-     *           (Could use dlopen() and dlsym() on Unix and corresponding
-     *           calls for Windows, but not portable...)
-     */
-    {
-#ifdef PNG_ASSEMBLER_CODE_SUPPORTED
-        png_uint_32 mmx_disable_mask = 0;
-        png_uint_32 asm_flags, mmx_mask;
-        int compilerID;
-
-        if (mainprog_ptr->nommxfilters)
-            mmx_disable_mask |= ( PNG_ASM_FLAG_MMX_READ_FILTER_SUB   \
-                                | PNG_ASM_FLAG_MMX_READ_FILTER_UP    \
-                                | PNG_ASM_FLAG_MMX_READ_FILTER_AVG   \
-                                | PNG_ASM_FLAG_MMX_READ_FILTER_PAETH );
-        if (mainprog_ptr->nommxcombine)
-            mmx_disable_mask |= PNG_ASM_FLAG_MMX_READ_COMBINE_ROW;
-        if (mainprog_ptr->nommxinterlace)
-            mmx_disable_mask |= PNG_ASM_FLAG_MMX_READ_INTERLACE;
-        asm_flags = png_get_asm_flags(png_ptr);
-        png_set_asm_flags(png_ptr, asm_flags & ~mmx_disable_mask);
-
-
-        /* Now query libpng's asm settings, just for yuks.  Note that this
-         * differs from the querying of its *potential* MMX capabilities
-         * in readpng2_version_info(); this is true runtime verification. */
-
-        asm_flags = png_get_asm_flags(png_ptr);
-        mmx_mask = png_get_mmx_flagmask(PNG_SELECT_READ | PNG_SELECT_WRITE,
-          &compilerID);
-        if (asm_flags & PNG_ASM_FLAG_MMX_SUPPORT_COMPILED)
-            fprintf(stderr,
-              "  MMX support (%s version) is compiled into libpng\n",
-              compilerID == 1? "MSVC++" :
-              (compilerID == 2? "GNU C" : "unknown"));
-        else
-            fprintf(stderr, "  MMX support is not compiled into libpng\n");
-        fprintf(stderr, "  MMX instructions are %ssupported by CPU\n",
-          (asm_flags & PNG_ASM_FLAG_MMX_SUPPORT_IN_CPU)? "" : "not ");
-        fprintf(stderr, "  MMX read support for combining rows is %sabled\n",
-          (asm_flags & PNG_ASM_FLAG_MMX_READ_COMBINE_ROW)? "en" : "dis");
-        fprintf(stderr,
-          "  MMX read support for expanding interlacing is %sabled\n",
-          (asm_flags & PNG_ASM_FLAG_MMX_READ_INTERLACE)? "en" : "dis");
-        fprintf(stderr, "  MMX read support for \"sub\" filter is %sabled\n",
-          (asm_flags & PNG_ASM_FLAG_MMX_READ_FILTER_SUB)? "en" : "dis");
-        fprintf(stderr, "  MMX read support for \"up\" filter is %sabled\n",
-          (asm_flags & PNG_ASM_FLAG_MMX_READ_FILTER_UP)? "en" : "dis");
-        fprintf(stderr, "  MMX read support for \"avg\" filter is %sabled\n",
-          (asm_flags & PNG_ASM_FLAG_MMX_READ_FILTER_AVG)? "en" : "dis");
-        fprintf(stderr, "  MMX read support for \"Paeth\" filter is %sabled\n",
-          (asm_flags & PNG_ASM_FLAG_MMX_READ_FILTER_PAETH)? "en" : "dis");
-        asm_flags &= (mmx_mask & ~( PNG_ASM_FLAG_MMX_READ_COMBINE_ROW  \
-                                  | PNG_ASM_FLAG_MMX_READ_INTERLACE    \
-                                  | PNG_ASM_FLAG_MMX_READ_FILTER_SUB   \
-                                  | PNG_ASM_FLAG_MMX_READ_FILTER_UP    \
-                                  | PNG_ASM_FLAG_MMX_READ_FILTER_AVG   \
-                                  | PNG_ASM_FLAG_MMX_READ_FILTER_PAETH ));
-        if (asm_flags)
-            fprintf(stderr,
-              "  additional MMX support is also enabled (0x%02lx)\n",
-              asm_flags);
-#else  /* !PNG_ASSEMBLER_CODE_SUPPORTED */
-        fprintf(stderr, "  MMX querying is disabled in libpng.\n");
-#endif /* ?PNG_ASSEMBLER_CODE_SUPPORTED */
-    }
-#endif
-
-
-    /* make sure we save our pointers for use in readpng2_decode_data() */
-
-    mainprog_ptr->png_ptr = png_ptr;
-    mainprog_ptr->info_ptr = info_ptr;
-
-
-    /* and that's all there is to initialization */
-
-    return 0;
-}
-
-
-
-
-/* returns 0 for success, 2 for libpng (longjmp) problem */
-
-int readpng2_decode_data(mainprog_info *mainprog_ptr, uch *rawbuf, ulg length)
-{
-    png_structp png_ptr = (png_structp)mainprog_ptr->png_ptr;
-    png_infop info_ptr = (png_infop)mainprog_ptr->info_ptr;
-
-
-    /* setjmp() must be called in every function that calls a PNG-reading
-     * libpng function */
-
-    if (setjmp(mainprog_ptr->jmpbuf)) {
-        png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
-        mainprog_ptr->png_ptr = NULL;
-        mainprog_ptr->info_ptr = NULL;
-        return 2;
-    }
-
-
-    /* hand off the next chunk of input data to libpng for decoding */
-
-    png_process_data(png_ptr, info_ptr, rawbuf, length);
-
-    return 0;
-}
-
-
-
-
-static void readpng2_info_callback(png_structp png_ptr, png_infop info_ptr)
-{
-    mainprog_info  *mainprog_ptr;
-    int  color_type, bit_depth;
-    double  gamma;
-
-
-    /* setjmp() doesn't make sense here, because we'd either have to exit(),
-     * longjmp() ourselves, or return control to libpng, which doesn't want
-     * to see us again.  By not doing anything here, libpng will instead jump
-     * to readpng2_decode_data(), which can return an error value to the main
-     * program. */
-
-
-    /* retrieve the pointer to our special-purpose struct, using the png_ptr
-     * that libpng passed back to us (i.e., not a global this time--there's
-     * no real difference for a single image, but for a multithreaded browser
-     * decoding several PNG images at the same time, one needs to avoid mixing
-     * up different images' structs) */
-
-    mainprog_ptr = png_get_progressive_ptr(png_ptr);
-
-    if (mainprog_ptr == NULL) {         /* we be hosed */
-        fprintf(stderr,
-          "readpng2 error:  main struct not recoverable in info_callback.\n");
-        fflush(stderr);
-        return;
-        /*
-         * Alternatively, we could call our error-handler just like libpng
-         * does, which would effectively terminate the program.  Since this
-         * can only happen if png_ptr gets redirected somewhere odd or the
-         * main PNG struct gets wiped, we're probably toast anyway.  (If
-         * png_ptr itself is NULL, we would not have been called.)
-         */
-    }
-
-
-    /* this is just like in the non-progressive case */
-
-    png_get_IHDR(png_ptr, info_ptr, &mainprog_ptr->width,
-      &mainprog_ptr->height, &bit_depth, &color_type, NULL, NULL, NULL);
-
-
-    /* since we know we've read all of the PNG file's "header" (i.e., up
-     * to IDAT), we can check for a background color here */
-
-    if (mainprog_ptr->need_bgcolor &&
-        png_get_valid(png_ptr, info_ptr, PNG_INFO_bKGD))
-    {
-        png_color_16p pBackground;
-
-        /* it is not obvious from the libpng documentation, but this function
-         * takes a pointer to a pointer, and it always returns valid red,
-         * green and blue values, regardless of color_type: */
-        png_get_bKGD(png_ptr, info_ptr, &pBackground);
-
-        /* however, it always returns the raw bKGD data, regardless of any
-         * bit-depth transformations, so check depth and adjust if necessary */
-        if (bit_depth == 16) {
-            mainprog_ptr->bg_red   = pBackground->red   >> 8;
-            mainprog_ptr->bg_green = pBackground->green >> 8;
-            mainprog_ptr->bg_blue  = pBackground->blue  >> 8;
-        } else if (color_type == PNG_COLOR_TYPE_GRAY && bit_depth < 8) {
-            if (bit_depth == 1)
-                mainprog_ptr->bg_red = mainprog_ptr->bg_green =
-                  mainprog_ptr->bg_blue = pBackground->gray? 255 : 0;
-            else if (bit_depth == 2)
-                mainprog_ptr->bg_red = mainprog_ptr->bg_green =
-                  mainprog_ptr->bg_blue = (255/3) * pBackground->gray;
-            else /* bit_depth == 4 */
-                mainprog_ptr->bg_red = mainprog_ptr->bg_green =
-                  mainprog_ptr->bg_blue = (255/15) * pBackground->gray;
-        } else {
-            mainprog_ptr->bg_red   = (uch)pBackground->red;
-            mainprog_ptr->bg_green = (uch)pBackground->green;
-            mainprog_ptr->bg_blue  = (uch)pBackground->blue;
-        }
-    }
-
-
-    /* as before, let libpng expand palette images to RGB, low-bit-depth
-     * grayscale images to 8 bits, transparency chunks to full alpha channel;
-     * strip 16-bit-per-sample images to 8 bits per sample; and convert
-     * grayscale to RGB[A] */
-
-    if (color_type == PNG_COLOR_TYPE_PALETTE)
-        png_set_expand(png_ptr);
-    if (color_type == PNG_COLOR_TYPE_GRAY && bit_depth < 8)
-        png_set_expand(png_ptr);
-    if (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS))
-        png_set_expand(png_ptr);
-    if (bit_depth == 16)
-        png_set_strip_16(png_ptr);
-    if (color_type == PNG_COLOR_TYPE_GRAY ||
-        color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
-        png_set_gray_to_rgb(png_ptr);
-
-
-    /* Unlike the basic viewer, which was designed to operate on local files,
-     * this program is intended to simulate a web browser--even though we
-     * actually read from a local file, too.  But because we are pretending
-     * that most of the images originate on the Internet, we follow the recom-
-     * mendation of the sRGB proposal and treat unlabelled images (no gAMA
-     * chunk) as existing in the sRGB color space.  That is, we assume that
-     * such images have a file gamma of 0.45455, which corresponds to a PC-like
-     * display system.  This change in assumptions will have no effect on a
-     * PC-like system, but on a Mac, SGI, NeXT or other system with a non-
-     * identity lookup table, it will darken unlabelled images, which effec-
-     * tively favors images from PC-like systems over those originating on
-     * the local platform.  Note that mainprog_ptr->display_exponent is the
-     * "gamma" value for the entire display system, i.e., the product of
-     * LUT_exponent and CRT_exponent. */
-
-    if (png_get_gAMA(png_ptr, info_ptr, &gamma))
-        png_set_gamma(png_ptr, mainprog_ptr->display_exponent, gamma);
-    else
-        png_set_gamma(png_ptr, mainprog_ptr->display_exponent, 0.45455);
-
-
-    /* we'll let libpng expand interlaced images, too */
-
-    mainprog_ptr->passes = png_set_interlace_handling(png_ptr);
-
-
-    /* all transformations have been registered; now update info_ptr data and
-     * then get rowbytes and channels */
-
-    png_read_update_info(png_ptr, info_ptr);
-
-    mainprog_ptr->rowbytes = (int)png_get_rowbytes(png_ptr, info_ptr);
-    mainprog_ptr->channels = png_get_channels(png_ptr, info_ptr);
-
-
-    /* Call the main program to allocate memory for the image buffer and
-     * initialize windows and whatnot.  (The old-style function-pointer
-     * invocation is used for compatibility with a few supposedly ANSI
-     * compilers that nevertheless barf on "fn_ptr()"-style syntax.) */
-
-    (*mainprog_ptr->mainprog_init)();
-
-
-    /* and that takes care of initialization */
-
-    return;
-}
-
-
-
-
-
-static void readpng2_row_callback(png_structp png_ptr, png_bytep new_row,
-                                  png_uint_32 row_num, int pass)
-{
-    mainprog_info  *mainprog_ptr;
-
-
-    /* first check whether the row differs from the previous pass; if not,
-     * nothing to combine or display */
-
-    if (!new_row)
-        return;
-
-
-    /* retrieve the pointer to our special-purpose struct so we can access
-     * the old rows and image-display callback function */
-
-    mainprog_ptr = png_get_progressive_ptr(png_ptr);
-
-
-    /* save the pass number for optional use by the front end */
-
-    mainprog_ptr->pass = pass;
-
-
-    /* have libpng either combine the new row data with the existing row data
-     * from previous passes (if interlaced) or else just copy the new row
-     * into the main program's image buffer */
-
-    png_progressive_combine_row(png_ptr, mainprog_ptr->row_pointers[row_num],
-      new_row);
-
-
-    /* finally, call the display routine in the main program with the number
-     * of the row we just updated */
-
-    (*mainprog_ptr->mainprog_display_row)(row_num);
-
-
-    /* and we're ready for more */
-
-    return;
-}
-
-
-
-
-
-static void readpng2_end_callback(png_structp png_ptr, png_infop info_ptr)
-{
-    mainprog_info  *mainprog_ptr;
-
-
-    /* retrieve the pointer to our special-purpose struct */
-
-    mainprog_ptr = png_get_progressive_ptr(png_ptr);
-
-
-    /* let the main program know that it should flush any buffered image
-     * data to the display now and set a "done" flag or whatever, but note
-     * that it SHOULD NOT DESTROY THE PNG STRUCTS YET--in other words, do
-     * NOT call readpng2_cleanup() either here or in the finish_display()
-     * routine; wait until control returns to the main program via
-     * readpng2_decode_data() */
-
-    (*mainprog_ptr->mainprog_finish_display)();
-
-
-    /* all done */
-
-    return;
-}
-
-
-
-
-
-void readpng2_cleanup(mainprog_info *mainprog_ptr)
-{
-    png_structp png_ptr = (png_structp)mainprog_ptr->png_ptr;
-    png_infop info_ptr = (png_infop)mainprog_ptr->info_ptr;
-
-    if (png_ptr && info_ptr)
-        png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
-
-    mainprog_ptr->png_ptr = NULL;
-    mainprog_ptr->info_ptr = NULL;
-}
-
-
-
-
-
-static void readpng2_error_handler(png_structp png_ptr, png_const_charp msg)
-{
-    mainprog_info  *mainprog_ptr;
-
-    /* This function, aside from the extra step of retrieving the "error
-     * pointer" (below) and the fact that it exists within the application
-     * rather than within libpng, is essentially identical to libpng's
-     * default error handler.  The second point is critical:  since both
-     * setjmp() and longjmp() are called from the same code, they are
-     * guaranteed to have compatible notions of how big a jmp_buf is,
-     * regardless of whether _BSD_SOURCE or anything else has (or has not)
-     * been defined. */
-
-    fprintf(stderr, "readpng2 libpng error: %s\n", msg);
-    fflush(stderr);
-
-    mainprog_ptr = png_get_error_ptr(png_ptr);
-    if (mainprog_ptr == NULL) {         /* we are completely hosed now */
-        fprintf(stderr,
-          "readpng2 severe error:  jmpbuf not recoverable; terminating.\n");
-        fflush(stderr);
-        exit(99);
-    }
-
-    longjmp(mainprog_ptr->jmpbuf, 1);
-}
diff --git a/contrib/gregbook/readpng2.h b/contrib/gregbook/readpng2.h
deleted file mode 100644
index fbfffb4..0000000
--- a/contrib/gregbook/readpng2.h
+++ /dev/null
@@ -1,121 +0,0 @@
-/*---------------------------------------------------------------------------
-
-   rpng2 - progressive-model PNG display program                 readpng2.h
-
-  ---------------------------------------------------------------------------
-
-      Copyright (c) 1998-2008 Greg Roelofs.  All rights reserved.
-
-      This software is provided "as is," without warranty of any kind,
-      express or implied.  In no event shall the author or contributors
-      be held liable for any damages arising in any way from the use of
-      this software.
-
-      The contents of this file are DUAL-LICENSED.  You may modify and/or
-      redistribute this software according to the terms of one of the
-      following two licenses (at your option):
-
-
-      LICENSE 1 ("BSD-like with advertising clause"):
-
-      Permission is granted to anyone to use this software for any purpose,
-      including commercial applications, and to alter it and redistribute
-      it freely, subject to the following restrictions:
-
-      1. Redistributions of source code must retain the above copyright
-         notice, disclaimer, and this list of conditions.
-      2. Redistributions in binary form must reproduce the above copyright
-         notice, disclaimer, and this list of conditions in the documenta-
-         tion and/or other materials provided with the distribution.
-      3. All advertising materials mentioning features or use of this
-         software must display the following acknowledgment:
-
-            This product includes software developed by Greg Roelofs
-            and contributors for the book, "PNG: The Definitive Guide,"
-            published by O'Reilly and Associates.
-
-
-      LICENSE 2 (GNU GPL v2 or later):
-
-      This program is free software; you can redistribute it and/or modify
-      it under the terms of the GNU General Public License as published by
-      the Free Software Foundation; either version 2 of the License, or
-      (at your option) any later version.
-
-      This program is distributed in the hope that it will be useful,
-      but WITHOUT ANY WARRANTY; without even the implied warranty of
-      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-      GNU General Public License for more details.
-
-      You should have received a copy of the GNU General Public License
-      along with this program; if not, write to the Free Software Foundation,
-      Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
-
-  ---------------------------------------------------------------------------*/
-
-#ifndef TRUE
-#  define TRUE 1
-#  define FALSE 0
-#endif
-
-#ifndef MAX
-#  define MAX(a,b)  ((a) > (b)? (a) : (b))
-#  define MIN(a,b)  ((a) < (b)? (a) : (b))
-#endif
-
-#ifdef DEBUG
-#  define Trace(x)  {fprintf x ; fflush(stderr); fflush(stdout);}
-#else
-#  define Trace(x)  ;
-#endif
-
-enum rpng2_states {
-    kPreInit = 0,
-    kWindowInit,
-    kDone
-};
-
-typedef unsigned char   uch;
-typedef unsigned short  ush;
-typedef unsigned long   ulg;
-
-typedef struct _mainprog_info {
-    double display_exponent;
-    ulg width;
-    ulg height;
-    void *png_ptr;
-    void *info_ptr;
-    void (*mainprog_init)(void);
-    void (*mainprog_display_row)(ulg row_num);
-    void (*mainprog_finish_display)(void);
-    uch *image_data;
-    uch **row_pointers;
-    jmp_buf jmpbuf;
-    int passes;              /* not used */
-    int pass;
-    int rowbytes;
-    int channels;
-    int need_bgcolor;
-#if (defined(__i386__) || defined(_M_IX86) || defined(__x86_64__))
-    int nommxfilters;
-    int nommxcombine;
-    int nommxinterlace;
-#endif
-    int state;
-    uch bg_red;
-    uch bg_green;
-    uch bg_blue;
-} mainprog_info;
-
-
-/* prototypes for public functions in readpng2.c */
-
-void readpng2_version_info(void);
-
-int readpng2_check_sig(uch *sig, int num);
-
-int readpng2_init(mainprog_info *mainprog_ptr);
-
-int readpng2_decode_data(mainprog_info *mainprog_ptr, uch *rawbuf, ulg length);
-
-void readpng2_cleanup(mainprog_info *mainprog_ptr);
diff --git a/contrib/gregbook/readppm.c b/contrib/gregbook/readppm.c
deleted file mode 100644
index be9a56d..0000000
--- a/contrib/gregbook/readppm.c
+++ /dev/null
@@ -1,179 +0,0 @@
-/*---------------------------------------------------------------------------
-
-   rpng - simple PNG display program                              readppm.c
-
-  ---------------------------------------------------------------------------
-
-   This is a special-purpose replacement for readpng.c that allows binary
-   PPM files to be used in place of PNG images.
-
-  ---------------------------------------------------------------------------
-
-      Copyright (c) 1998-2007 Greg Roelofs.  All rights reserved.
-
-      This software is provided "as is," without warranty of any kind,
-      express or implied.  In no event shall the author or contributors
-      be held liable for any damages arising in any way from the use of
-      this software.
-
-      The contents of this file are DUAL-LICENSED.  You may modify and/or
-      redistribute this software according to the terms of one of the
-      following two licenses (at your option):
-
-
-      LICENSE 1 ("BSD-like with advertising clause"):
-
-      Permission is granted to anyone to use this software for any purpose,
-      including commercial applications, and to alter it and redistribute
-      it freely, subject to the following restrictions:
-
-      1. Redistributions of source code must retain the above copyright
-         notice, disclaimer, and this list of conditions.
-      2. Redistributions in binary form must reproduce the above copyright
-         notice, disclaimer, and this list of conditions in the documenta-
-         tion and/or other materials provided with the distribution.
-      3. All advertising materials mentioning features or use of this
-         software must display the following acknowledgment:
-
-            This product includes software developed by Greg Roelofs
-            and contributors for the book, "PNG: The Definitive Guide,"
-            published by O'Reilly and Associates.
-
-
-      LICENSE 2 (GNU GPL v2 or later):
-
-      This program is free software; you can redistribute it and/or modify
-      it under the terms of the GNU General Public License as published by
-      the Free Software Foundation; either version 2 of the License, or
-      (at your option) any later version.
-
-      This program is distributed in the hope that it will be useful,
-      but WITHOUT ANY WARRANTY; without even the implied warranty of
-      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-      GNU General Public License for more details.
-
-      You should have received a copy of the GNU General Public License
-      along with this program; if not, write to the Free Software Foundation,
-      Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
-
-  ---------------------------------------------------------------------------*/
-
-#include <stdio.h>
-#include <stdlib.h>
-
-#include "readpng.h"    /* typedefs, common macros, public prototypes */
-
-
-ulg  width, height;
-int  bit_depth, color_type, channels;
-uch  *image_data = NULL;
-FILE *saved_infile;
-
-
-void readpng_version_info()
-{
-    fprintf(stderr, "   Compiled without libpng, zlib or PBMPLUS/NetPBM.\n");
-}
-
-
-/* return value = 0 for success, 1 for bad sig, 2 for bad IHDR, 4 for no mem */
-
-int readpng_init(FILE *infile, ulg *pWidth, ulg *pHeight)
-{
-    static uch ppmline[256];
-    int maxval;
-
-
-    saved_infile = infile;
-
-    fgets(ppmline, 256, infile);
-    if (ppmline[0] != 'P' || ppmline[1] != '6') {
-        fprintf(stderr, "ERROR:  not a PPM file\n");
-        return 1;
-    }
-    /* possible color types:  P5 = grayscale (0), P6 = RGB (2), P8 = RGBA (6) */
-    if (ppmline[1] == '6') {
-        color_type = 2;
-        channels = 3;
-    } else if (ppmline[1] == '8') {
-        color_type = 6;
-        channels = 4;
-    } else /* if (ppmline[1] == '5') */ {
-        color_type = 0;
-        channels = 1;
-    }
-
-    do {
-        fgets(ppmline, 256, infile);
-    } while (ppmline[0] == '#');
-    sscanf(ppmline, "%lu %lu", &width, &height);
-
-    do {
-        fgets(ppmline, 256, infile);
-    } while (ppmline[0] == '#');
-    sscanf(ppmline, "%d", &maxval);
-    if (maxval != 255) {
-        fprintf(stderr, "ERROR:  maxval = %d\n", maxval);
-        return 2;
-    }
-    bit_depth = 8;
-
-    *pWidth = width;
-    *pHeight = height;
-
-    return 0;
-}
-
-
-
-
-/* returns 0 if succeeds, 1 if fails due to no bKGD chunk, 2 if libpng error;
- * scales values to 8-bit if necessary */
-
-int readpng_get_bgcolor(uch *red, uch *green, uch *blue)
-{
-    return 1;
-}
-
-
-
-
-/* display_exponent == LUT_exponent * CRT_exponent */
-
-uch *readpng_get_image(double display_exponent, int *pChannels, ulg *pRowbytes)
-{
-    ulg  rowbytes;
-
-
-    /* expand palette images to RGB, low-bit-depth grayscale images to 8 bits,
-     * transparency chunks to full alpha channel; strip 16-bit-per-sample
-     * images to 8 bits per sample; and convert grayscale to RGB[A] */
-
-    /* GRR WARNING:  grayscale needs to be expanded and channels reset! */
-
-    *pRowbytes = rowbytes = channels*width;
-    *pChannels = channels;
-
-    if ((image_data = (uch *)malloc(rowbytes*height)) == NULL) {
-        return NULL;
-    }
-
-    Trace((stderr, "readpng_get_image:  rowbytes = %ld, height = %ld\n", rowbytes, height));
-
-
-    /* now we can go ahead and just read the whole image */
-
-    fread(image_data, 1L, rowbytes*height, saved_infile);
-
-
-    return image_data;
-}
-
-
-void readpng_cleanup(int free_image_data)
-{
-    if (free_image_data && image_data) {
-        free(image_data);
-        image_data = NULL;
-    }
-}
diff --git a/contrib/gregbook/rpng-win.c b/contrib/gregbook/rpng-win.c
deleted file mode 100644
index 2020961..0000000
--- a/contrib/gregbook/rpng-win.c
+++ /dev/null
@@ -1,684 +0,0 @@
-/*---------------------------------------------------------------------------
-
-   rpng - simple PNG display program                             rpng-win.c
-
-   This program decodes and displays PNG images, with gamma correction and
-   optionally with a user-specified background color (in case the image has
-   transparency).  It is very nearly the most basic PNG viewer possible.
-   This version is for 32-bit Windows; it may compile under 16-bit Windows
-   with a little tweaking (or maybe not).
-
-   to do:
-    - handle quoted command-line args (especially filenames with spaces)
-    - have minimum window width:  oh well
-    - use %.1023s to simplify truncation of title-bar string?
-
-  ---------------------------------------------------------------------------
-
-   Changelog:
-    - 1.00:  initial public release
-    - 1.01:  modified to allow abbreviated options; fixed long/ulong mis-
-              match; switched to png_jmpbuf() macro
-    - 1.02:  added extra set of parentheses to png_jmpbuf() macro; fixed
-              command-line parsing bug
-    - 1.10:  enabled "message window"/console (thanks to David Geldreich)
-    - 2.00:  dual-licensed (added GNU GPL)
-    - 2.01:  fixed improper display of usage screen on PNG error(s)
-
-  ---------------------------------------------------------------------------
-
-      Copyright (c) 1998-2008 Greg Roelofs.  All rights reserved.
-
-      This software is provided "as is," without warranty of any kind,
-      express or implied.  In no event shall the author or contributors
-      be held liable for any damages arising in any way from the use of
-      this software.
-
-      The contents of this file are DUAL-LICENSED.  You may modify and/or
-      redistribute this software according to the terms of one of the
-      following two licenses (at your option):
-
-
-      LICENSE 1 ("BSD-like with advertising clause"):
-
-      Permission is granted to anyone to use this software for any purpose,
-      including commercial applications, and to alter it and redistribute
-      it freely, subject to the following restrictions:
-
-      1. Redistributions of source code must retain the above copyright
-         notice, disclaimer, and this list of conditions.
-      2. Redistributions in binary form must reproduce the above copyright
-         notice, disclaimer, and this list of conditions in the documenta-
-         tion and/or other materials provided with the distribution.
-      3. All advertising materials mentioning features or use of this
-         software must display the following acknowledgment:
-
-            This product includes software developed by Greg Roelofs
-            and contributors for the book, "PNG: The Definitive Guide,"
-            published by O'Reilly and Associates.
-
-
-      LICENSE 2 (GNU GPL v2 or later):
-
-      This program is free software; you can redistribute it and/or modify
-      it under the terms of the GNU General Public License as published by
-      the Free Software Foundation; either version 2 of the License, or
-      (at your option) any later version.
-
-      This program is distributed in the hope that it will be useful,
-      but WITHOUT ANY WARRANTY; without even the implied warranty of
-      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-      GNU General Public License for more details.
-
-      You should have received a copy of the GNU General Public License
-      along with this program; if not, write to the Free Software Foundation,
-      Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
-
-  ---------------------------------------------------------------------------*/
-
-#define PROGNAME  "rpng-win"
-#define LONGNAME  "Simple PNG Viewer for Windows"
-#define VERSION   "2.01 of 16 March 2008"
-
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <time.h>
-#include <windows.h>
-#include <conio.h>      /* only for _getch() */
-
-/* #define DEBUG  :  this enables the Trace() macros */
-
-#include "readpng.h"    /* typedefs, common macros, readpng prototypes */
-
-
-/* could just include png.h, but this macro is the only thing we need
- * (name and typedefs changed to local versions); note that side effects
- * only happen with alpha (which could easily be avoided with
- * "ush acopy = (alpha);") */
-
-#define alpha_composite(composite, fg, alpha, bg) {               \
-    ush temp = ((ush)(fg)*(ush)(alpha) +                          \
-                (ush)(bg)*(ush)(255 - (ush)(alpha)) + (ush)128);  \
-    (composite) = (uch)((temp + (temp >> 8)) >> 8);               \
-}
-
-
-/* local prototypes */
-static int        rpng_win_create_window(HINSTANCE hInst, int showmode);
-static int        rpng_win_display_image(void);
-static void       rpng_win_cleanup(void);
-LRESULT CALLBACK  rpng_win_wndproc(HWND, UINT, WPARAM, LPARAM);
-
-
-static char titlebar[1024];
-static char *progname = PROGNAME;
-static char *appname = LONGNAME;
-static char *filename;
-static FILE *infile;
-
-static char *bgstr;
-static uch bg_red=0, bg_green=0, bg_blue=0;
-
-static double display_exponent;
-
-static ulg image_width, image_height, image_rowbytes;
-static int image_channels;
-static uch *image_data;
-
-/* Windows-specific variables */
-static ulg wimage_rowbytes;
-static uch *dib;
-static uch *wimage_data;
-static BITMAPINFOHEADER *bmih;
-
-static HWND global_hwnd;
-
-
-
-
-int WINAPI WinMain(HINSTANCE hInst, HINSTANCE hPrevInst, PSTR cmd, int showmode)
-{
-    char *args[1024];                 /* arbitrary limit, but should suffice */
-    char *p, *q, **argv = args;
-    int argc = 0;
-    int rc, alen, flen;
-    int error = 0;
-    int have_bg = FALSE;
-    double LUT_exponent;              /* just the lookup table */
-    double CRT_exponent = 2.2;        /* just the monitor */
-    double default_display_exponent;  /* whole display system */
-    MSG msg;
-
-
-    filename = (char *)NULL;
-
-
-    /* First reenable console output, which normally goes to the bit bucket
-     * for windowed apps.  Closing the console window will terminate the
-     * app.  Thanks to David.Geldreich@realviz.com for supplying the magical
-     * incantation. */
-
-    AllocConsole();
-    freopen("CONOUT$", "a", stderr);
-    freopen("CONOUT$", "a", stdout);
-
-
-    /* Next set the default value for our display-system exponent, i.e.,
-     * the product of the CRT exponent and the exponent corresponding to
-     * the frame-buffer's lookup table (LUT), if any.  This is not an
-     * exhaustive list of LUT values (e.g., OpenStep has a lot of weird
-     * ones), but it should cover 99% of the current possibilities.  And
-     * yes, these ifdefs are completely wasted in a Windows program... */
-
-#if defined(NeXT)
-    LUT_exponent = 1.0 / 2.2;
-    /*
-    if (some_next_function_that_returns_gamma(&next_gamma))
-        LUT_exponent = 1.0 / next_gamma;
-     */
-#elif defined(sgi)
-    LUT_exponent = 1.0 / 1.7;
-    /* there doesn't seem to be any documented function to get the
-     * "gamma" value, so we do it the hard way */
-    infile = fopen("/etc/config/system.glGammaVal", "r");
-    if (infile) {
-        double sgi_gamma;
-
-        fgets(tmpline, 80, infile);
-        fclose(infile);
-        sgi_gamma = atof(tmpline);
-        if (sgi_gamma > 0.0)
-            LUT_exponent = 1.0 / sgi_gamma;
-    }
-#elif defined(Macintosh)
-    LUT_exponent = 1.8 / 2.61;
-    /*
-    if (some_mac_function_that_returns_gamma(&mac_gamma))
-        LUT_exponent = mac_gamma / 2.61;
-     */
-#else
-    LUT_exponent = 1.0;   /* assume no LUT:  most PCs */
-#endif
-
-    /* the defaults above give 1.0, 1.3, 1.5 and 2.2, respectively: */
-    default_display_exponent = LUT_exponent * CRT_exponent;
-
-
-    /* If the user has set the SCREEN_GAMMA environment variable as suggested
-     * (somewhat imprecisely) in the libpng documentation, use that; otherwise
-     * use the default value we just calculated.  Either way, the user may
-     * override this via a command-line option. */
-
-    if ((p = getenv("SCREEN_GAMMA")) != NULL)
-        display_exponent = atof(p);
-    else
-        display_exponent = default_display_exponent;
-
-
-    /* Windows really hates command lines, so we have to set up our own argv.
-     * Note that we do NOT bother with quoted arguments here, so don't use
-     * filenames with spaces in 'em! */
-
-    argv[argc++] = PROGNAME;
-    p = cmd;
-    for (;;) {
-        if (*p == ' ')
-            while (*++p == ' ')
-                ;
-        /* now p points at the first non-space after some spaces */
-        if (*p == '\0')
-            break;    /* nothing after the spaces:  done */
-        argv[argc++] = q = p;
-        while (*q && *q != ' ')
-            ++q;
-        /* now q points at a space or the end of the string */
-        if (*q == '\0')
-            break;    /* last argv already terminated; quit */
-        *q = '\0';    /* change space to terminator */
-        p = q + 1;
-    }
-    argv[argc] = NULL;   /* terminate the argv array itself */
-
-
-    /* Now parse the command line for options and the PNG filename. */
-
-    while (*++argv && !error) {
-        if (!strncmp(*argv, "-gamma", 2)) {
-            if (!*++argv)
-                ++error;
-            else {
-                display_exponent = atof(*argv);
-                if (display_exponent <= 0.0)
-                    ++error;
-            }
-        } else if (!strncmp(*argv, "-bgcolor", 2)) {
-            if (!*++argv)
-                ++error;
-            else {
-                bgstr = *argv;
-                if (strlen(bgstr) != 7 || bgstr[0] != '#')
-                    ++error;
-                else
-                    have_bg = TRUE;
-            }
-        } else {
-            if (**argv != '-') {
-                filename = *argv;
-                if (argv[1])   /* shouldn't be any more args after filename */
-                    ++error;
-            } else
-                ++error;   /* not expecting any other options */
-        }
-    }
-
-    if (!filename)
-        ++error;
-
-
-    /* print usage screen if any errors up to this point */
-
-    if (error) {
-        int ch;
-
-        fprintf(stderr, "\n%s %s:  %s\n\n", PROGNAME, VERSION, appname);
-        readpng_version_info();
-        fprintf(stderr, "\n"
-          "Usage:  %s [-gamma exp] [-bgcolor bg] file.png\n"
-          "    exp \ttransfer-function exponent (``gamma'') of the display\n"
-          "\t\t  system in floating-point format (e.g., ``%.1f''); equal\n"
-          "\t\t  to the product of the lookup-table exponent (varies)\n"
-          "\t\t  and the CRT exponent (usually 2.2); must be positive\n"
-          "    bg  \tdesired background color in 7-character hex RGB format\n"
-          "\t\t  (e.g., ``#ff7700'' for orange:  same as HTML colors);\n"
-          "\t\t  used with transparent images\n"
-          "\nPress Q, Esc or mouse button 1 after image is displayed to quit.\n"
-          "Press Q or Esc to quit this usage screen.\n"
-          "\n", PROGNAME, default_display_exponent);
-        do
-            ch = _getch();
-        while (ch != 'q' && ch != 'Q' && ch != 0x1B);
-        exit(1);
-    }
-
-
-    if (!(infile = fopen(filename, "rb"))) {
-        fprintf(stderr, PROGNAME ":  can't open PNG file [%s]\n", filename);
-        ++error;
-    } else {
-        if ((rc = readpng_init(infile, &image_width, &image_height)) != 0) {
-            switch (rc) {
-                case 1:
-                    fprintf(stderr, PROGNAME
-                      ":  [%s] is not a PNG file: incorrect signature\n",
-                      filename);
-                    break;
-                case 2:
-                    fprintf(stderr, PROGNAME
-                      ":  [%s] has bad IHDR (libpng longjmp)\n", filename);
-                    break;
-                case 4:
-                    fprintf(stderr, PROGNAME ":  insufficient memory\n");
-                    break;
-                default:
-                    fprintf(stderr, PROGNAME
-                      ":  unknown readpng_init() error\n");
-                    break;
-            }
-            ++error;
-        }
-        if (error)
-            fclose(infile);
-    }
-
-
-    if (error) {
-        int ch;
-
-        fprintf(stderr, PROGNAME ":  aborting.\n");
-        do
-            ch = _getch();
-        while (ch != 'q' && ch != 'Q' && ch != 0x1B);
-        exit(2);
-    } else {
-        fprintf(stderr, "\n%s %s:  %s\n", PROGNAME, VERSION, appname);
-        fprintf(stderr,
-          "\n   [console window:  closing this window will terminate %s]\n\n",
-          PROGNAME);
-    }
-
-
-    /* set the title-bar string, but make sure buffer doesn't overflow */
-
-    alen = strlen(appname);
-    flen = strlen(filename);
-    if (alen + flen + 3 > 1023)
-        sprintf(titlebar, "%s:  ...%s", appname, filename+(alen+flen+6-1023));
-    else
-        sprintf(titlebar, "%s:  %s", appname, filename);
-
-
-    /* if the user didn't specify a background color on the command line,
-     * check for one in the PNG file--if not, the initialized values of 0
-     * (black) will be used */
-
-    if (have_bg) {
-        unsigned r, g, b;   /* this approach quiets compiler warnings */
-
-        sscanf(bgstr+1, "%2x%2x%2x", &r, &g, &b);
-        bg_red   = (uch)r;
-        bg_green = (uch)g;
-        bg_blue  = (uch)b;
-    } else if (readpng_get_bgcolor(&bg_red, &bg_green, &bg_blue) > 1) {
-        readpng_cleanup(TRUE);
-        fprintf(stderr, PROGNAME
-          ":  libpng error while checking for background color\n");
-        exit(2);
-    }
-
-
-    /* do the basic Windows initialization stuff, make the window and fill it
-     * with the background color */
-
-    if (rpng_win_create_window(hInst, showmode))
-        exit(2);
-
-
-    /* decode the image, all at once */
-
-    Trace((stderr, "calling readpng_get_image()\n"))
-    image_data = readpng_get_image(display_exponent, &image_channels,
-      &image_rowbytes);
-    Trace((stderr, "done with readpng_get_image()\n"))
-
-
-    /* done with PNG file, so clean up to minimize memory usage (but do NOT
-     * nuke image_data!) */
-
-    readpng_cleanup(FALSE);
-    fclose(infile);
-
-    if (!image_data) {
-        fprintf(stderr, PROGNAME ":  unable to decode PNG image\n");
-        exit(3);
-    }
-
-
-    /* display image (composite with background if requested) */
-
-    Trace((stderr, "calling rpng_win_display_image()\n"))
-    if (rpng_win_display_image()) {
-        free(image_data);
-        exit(4);
-    }
-    Trace((stderr, "done with rpng_win_display_image()\n"))
-
-
-    /* wait for the user to tell us when to quit */
-
-    printf(
-      "Done.  Press Q, Esc or mouse button 1 (within image window) to quit.\n");
-    fflush(stdout);
-
-    while (GetMessage(&msg, NULL, 0, 0)) {
-        TranslateMessage(&msg);
-        DispatchMessage(&msg);
-    }
-
-
-    /* OK, we're done:  clean up all image and Windows resources and go away */
-
-    rpng_win_cleanup();
-
-    return msg.wParam;
-}
-
-
-
-
-
-static int rpng_win_create_window(HINSTANCE hInst, int showmode)
-{
-    uch *dest;
-    int extra_width, extra_height;
-    ulg i, j;
-    WNDCLASSEX wndclass;
-
-
-/*---------------------------------------------------------------------------
-    Allocate memory for the display-specific version of the image (round up
-    to multiple of 4 for Windows DIB).
-  ---------------------------------------------------------------------------*/
-
-    wimage_rowbytes = ((3*image_width + 3L) >> 2) << 2;
-
-    if (!(dib = (uch *)malloc(sizeof(BITMAPINFOHEADER) +
-                              wimage_rowbytes*image_height)))
-    {
-        return 4;   /* fail */
-    }
-
-/*---------------------------------------------------------------------------
-    Initialize the DIB.  Negative height means to use top-down BMP ordering
-    (must be uncompressed, but that's what we want).  Bit count of 1, 4 or 8
-    implies a colormap of RGBX quads, but 24-bit BMPs just use B,G,R values
-    directly => wimage_data begins immediately after BMP header.
-  ---------------------------------------------------------------------------*/
-
-    memset(dib, 0, sizeof(BITMAPINFOHEADER));
-    bmih = (BITMAPINFOHEADER *)dib;
-    bmih->biSize = sizeof(BITMAPINFOHEADER);
-    bmih->biWidth = image_width;
-    bmih->biHeight = -((long)image_height);
-    bmih->biPlanes = 1;
-    bmih->biBitCount = 24;
-    bmih->biCompression = 0;
-    wimage_data = dib + sizeof(BITMAPINFOHEADER);
-
-/*---------------------------------------------------------------------------
-    Fill in background color (black by default); data are in BGR order.
-  ---------------------------------------------------------------------------*/
-
-    for (j = 0;  j < image_height;  ++j) {
-        dest = wimage_data + j*wimage_rowbytes;
-        for (i = image_width;  i > 0;  --i) {
-            *dest++ = bg_blue;
-            *dest++ = bg_green;
-            *dest++ = bg_red;
-        }
-    }
-
-/*---------------------------------------------------------------------------
-    Set the window parameters.
-  ---------------------------------------------------------------------------*/
-
-    memset(&wndclass, 0, sizeof(wndclass));
-
-    wndclass.cbSize = sizeof(wndclass);
-    wndclass.style = CS_HREDRAW | CS_VREDRAW;
-    wndclass.lpfnWndProc = rpng_win_wndproc;
-    wndclass.hInstance = hInst;
-    wndclass.hIcon = LoadIcon(NULL, IDI_APPLICATION);
-    wndclass.hCursor = LoadCursor(NULL, IDC_ARROW);
-    wndclass.hbrBackground = (HBRUSH)GetStockObject(DKGRAY_BRUSH);
-    wndclass.lpszMenuName = NULL;
-    wndclass.lpszClassName = progname;
-    wndclass.hIconSm = LoadIcon(NULL, IDI_APPLICATION);
-
-    RegisterClassEx(&wndclass);
-
-/*---------------------------------------------------------------------------
-    Finally, create the window.
-  ---------------------------------------------------------------------------*/
-
-    extra_width  = 2*(GetSystemMetrics(SM_CXBORDER) +
-                      GetSystemMetrics(SM_CXDLGFRAME));
-    extra_height = 2*(GetSystemMetrics(SM_CYBORDER) +
-                      GetSystemMetrics(SM_CYDLGFRAME)) +
-                      GetSystemMetrics(SM_CYCAPTION);
-
-    global_hwnd = CreateWindow(progname, titlebar, WS_OVERLAPPEDWINDOW,
-      CW_USEDEFAULT, CW_USEDEFAULT, image_width+extra_width,
-      image_height+extra_height, NULL, NULL, hInst, NULL);
-
-    ShowWindow(global_hwnd, showmode);
-    UpdateWindow(global_hwnd);
-
-    return 0;
-
-} /* end function rpng_win_create_window() */
-
-
-
-
-
-static int rpng_win_display_image()
-{
-    uch *src, *dest;
-    uch r, g, b, a;
-    ulg i, row, lastrow;
-    RECT rect;
-
-
-    Trace((stderr, "beginning display loop (image_channels == %d)\n",
-      image_channels))
-    Trace((stderr, "(width = %ld, rowbytes = %ld, wimage_rowbytes = %d)\n",
-      image_width, image_rowbytes, wimage_rowbytes))
-
-
-/*---------------------------------------------------------------------------
-    Blast image data to buffer.  This whole routine takes place before the
-    message loop begins, so there's no real point in any pseudo-progressive
-    display...
-  ---------------------------------------------------------------------------*/
-
-    for (lastrow = row = 0;  row < image_height;  ++row) {
-        src = image_data + row*image_rowbytes;
-        dest = wimage_data + row*wimage_rowbytes;
-        if (image_channels == 3) {
-            for (i = image_width;  i > 0;  --i) {
-                r = *src++;
-                g = *src++;
-                b = *src++;
-                *dest++ = b;
-                *dest++ = g;   /* note reverse order */
-                *dest++ = r;
-            }
-        } else /* if (image_channels == 4) */ {
-            for (i = image_width;  i > 0;  --i) {
-                r = *src++;
-                g = *src++;
-                b = *src++;
-                a = *src++;
-                if (a == 255) {
-                    *dest++ = b;
-                    *dest++ = g;
-                    *dest++ = r;
-                } else if (a == 0) {
-                    *dest++ = bg_blue;
-                    *dest++ = bg_green;
-                    *dest++ = bg_red;
-                } else {
-                    /* this macro (copied from png.h) composites the
-                     * foreground and background values and puts the
-                     * result into the first argument; there are no
-                     * side effects with the first argument */
-                    alpha_composite(*dest++, b, a, bg_blue);
-                    alpha_composite(*dest++, g, a, bg_green);
-                    alpha_composite(*dest++, r, a, bg_red);
-                }
-            }
-        }
-        /* display after every 16 lines */
-        if (((row+1) & 0xf) == 0) {
-            rect.left = 0L;
-            rect.top = (LONG)lastrow;
-            rect.right = (LONG)image_width;      /* possibly off by one? */
-            rect.bottom = (LONG)lastrow + 16L;   /* possibly off by one? */
-            InvalidateRect(global_hwnd, &rect, FALSE);
-            UpdateWindow(global_hwnd);     /* similar to XFlush() */
-            lastrow = row + 1;
-        }
-    }
-
-    Trace((stderr, "calling final image-flush routine\n"))
-    if (lastrow < image_height) {
-        rect.left = 0L;
-        rect.top = (LONG)lastrow;
-        rect.right = (LONG)image_width;      /* possibly off by one? */
-        rect.bottom = (LONG)image_height;    /* possibly off by one? */
-        InvalidateRect(global_hwnd, &rect, FALSE);
-        UpdateWindow(global_hwnd);     /* similar to XFlush() */
-    }
-
-/*
-    last param determines whether or not background is wiped before paint
-    InvalidateRect(global_hwnd, NULL, TRUE);
-    UpdateWindow(global_hwnd);
- */
-
-    return 0;
-}
-
-
-
-
-
-static void rpng_win_cleanup()
-{
-    if (image_data) {
-        free(image_data);
-        image_data = NULL;
-    }
-
-    if (dib) {
-        free(dib);
-        dib = NULL;
-    }
-}
-
-
-
-
-
-LRESULT CALLBACK rpng_win_wndproc(HWND hwnd, UINT iMsg, WPARAM wP, LPARAM lP)
-{
-    HDC         hdc;
-    PAINTSTRUCT ps;
-    int rc;
-
-    switch (iMsg) {
-        case WM_CREATE:
-            /* one-time processing here, if any */
-            return 0;
-
-        case WM_PAINT:
-            hdc = BeginPaint(hwnd, &ps);
-                    /*                    dest                          */
-            rc = StretchDIBits(hdc, 0, 0, image_width, image_height,
-                    /*                    source                        */
-                                    0, 0, image_width, image_height,
-                                    wimage_data, (BITMAPINFO *)bmih,
-                    /*              iUsage: no clue                     */
-                                    0, SRCCOPY);
-            EndPaint(hwnd, &ps);
-            return 0;
-
-        /* wait for the user to tell us when to quit */
-        case WM_CHAR:
-            switch (wP) {      /* only need one, so ignore repeat count */
-                case 'q':
-                case 'Q':
-                case 0x1B:     /* Esc key */
-                    PostQuitMessage(0);
-            }
-            return 0;
-
-        case WM_LBUTTONDOWN:   /* another way of quitting */
-        case WM_DESTROY:
-            PostQuitMessage(0);
-            return 0;
-    }
-
-    return DefWindowProc(hwnd, iMsg, wP, lP);
-}
diff --git a/contrib/gregbook/rpng-x.c b/contrib/gregbook/rpng-x.c
deleted file mode 100644
index 0a98170..0000000
--- a/contrib/gregbook/rpng-x.c
+++ /dev/null
@@ -1,904 +0,0 @@
-/*---------------------------------------------------------------------------
-
-   rpng - simple PNG display program                               rpng-x.c
-
-   This program decodes and displays PNG images, with gamma correction and
-   optionally with a user-specified background color (in case the image has
-   transparency).  It is very nearly the most basic PNG viewer possible.
-   This version is for the X Window System (tested by author under Unix and
-   by Martin Zinser under OpenVMS; may work under OS/2 with some tweaking).
-
-   to do:
-    - 8-bit (colormapped) X support
-    - use %.1023s to simplify truncation of title-bar string?
-
-  ---------------------------------------------------------------------------
-
-   Changelog:
-    - 1.01:  initial public release
-    - 1.02:  modified to allow abbreviated options; fixed long/ulong mis-
-              match; switched to png_jmpbuf() macro
-    - 1.10:  added support for non-default visuals; fixed X pixel-conversion
-    - 1.11:  added extra set of parentheses to png_jmpbuf() macro; fixed
-              command-line parsing bug
-    - 1.12:  fixed some small X memory leaks (thanks to François Petitjean)
-    - 1.13:  fixed XFreeGC() crash bug (thanks to Patrick Welche)
-    - 1.14:  added support for X resources (thanks to Gerhard Niklasch)
-    - 2.00:  dual-licensed (added GNU GPL)
-    - 2.01:  fixed improper display of usage screen on PNG error(s)
-
-  ---------------------------------------------------------------------------
-
-      Copyright (c) 1998-2008 Greg Roelofs.  All rights reserved.
-
-      This software is provided "as is," without warranty of any kind,
-      express or implied.  In no event shall the author or contributors
-      be held liable for any damages arising in any way from the use of
-      this software.
-
-      The contents of this file are DUAL-LICENSED.  You may modify and/or
-      redistribute this software according to the terms of one of the
-      following two licenses (at your option):
-
-
-      LICENSE 1 ("BSD-like with advertising clause"):
-
-      Permission is granted to anyone to use this software for any purpose,
-      including commercial applications, and to alter it and redistribute
-      it freely, subject to the following restrictions:
-
-      1. Redistributions of source code must retain the above copyright
-         notice, disclaimer, and this list of conditions.
-      2. Redistributions in binary form must reproduce the above copyright
-         notice, disclaimer, and this list of conditions in the documenta-
-         tion and/or other materials provided with the distribution.
-      3. All advertising materials mentioning features or use of this
-         software must display the following acknowledgment:
-
-            This product includes software developed by Greg Roelofs
-            and contributors for the book, "PNG: The Definitive Guide,"
-            published by O'Reilly and Associates.
-
-
-      LICENSE 2 (GNU GPL v2 or later):
-
-      This program is free software; you can redistribute it and/or modify
-      it under the terms of the GNU General Public License as published by
-      the Free Software Foundation; either version 2 of the License, or
-      (at your option) any later version.
-
-      This program is distributed in the hope that it will be useful,
-      but WITHOUT ANY WARRANTY; without even the implied warranty of
-      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-      GNU General Public License for more details.
-
-      You should have received a copy of the GNU General Public License
-      along with this program; if not, write to the Free Software Foundation,
-      Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
-
-  ---------------------------------------------------------------------------*/
-
-#define PROGNAME  "rpng-x"
-#define LONGNAME  "Simple PNG Viewer for X"
-#define VERSION   "2.01 of 16 March 2008"
-#define RESNAME   "rpng"	/* our X resource application name */
-#define RESCLASS  "Rpng"	/* our X resource class name */
-
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <time.h>
-#include <X11/Xlib.h>
-#include <X11/Xutil.h>
-#include <X11/Xos.h>
-#include <X11/keysym.h>
-
-/* #define DEBUG  :  this enables the Trace() macros */
-
-#include "readpng.h"   /* typedefs, common macros, readpng prototypes */
-
-
-/* could just include png.h, but this macro is the only thing we need
- * (name and typedefs changed to local versions); note that side effects
- * only happen with alpha (which could easily be avoided with
- * "ush acopy = (alpha);") */
-
-#define alpha_composite(composite, fg, alpha, bg) {               \
-    ush temp = ((ush)(fg)*(ush)(alpha) +                          \
-                (ush)(bg)*(ush)(255 - (ush)(alpha)) + (ush)128);  \
-    (composite) = (uch)((temp + (temp >> 8)) >> 8);               \
-}
-
-
-/* local prototypes */
-static int  rpng_x_create_window(void);
-static int  rpng_x_display_image(void);
-static void rpng_x_cleanup(void);
-static int  rpng_x_msb(ulg u32val);
-
-
-static char titlebar[1024], *window_name = titlebar;
-static char *appname = LONGNAME;
-static char *icon_name = PROGNAME;
-static char *res_name = RESNAME;
-static char *res_class = RESCLASS;
-static char *filename;
-static FILE *infile;
-
-static char *bgstr;
-static uch bg_red=0, bg_green=0, bg_blue=0;
-
-static double display_exponent;
-
-static ulg image_width, image_height, image_rowbytes;
-static int image_channels;
-static uch *image_data;
-
-/* X-specific variables */
-static char *displayname;
-static XImage *ximage;
-static Display *display;
-static int depth;
-static Visual *visual;
-static XVisualInfo *visual_list;
-static int RShift, GShift, BShift;
-static ulg RMask, GMask, BMask;
-static Window window;
-static GC gc;
-static Colormap colormap;
-
-static int have_nondefault_visual = FALSE;
-static int have_colormap = FALSE;
-static int have_window = FALSE;
-static int have_gc = FALSE;
-/*
-ulg numcolors=0, pixels[256];
-ush reds[256], greens[256], blues[256];
- */
-
-
-
-
-int main(int argc, char **argv)
-{
-#ifdef sgi
-    char tmpline[80];
-#endif
-    char *p;
-    int rc, alen, flen;
-    int error = 0;
-    int have_bg = FALSE;
-    double LUT_exponent;               /* just the lookup table */
-    double CRT_exponent = 2.2;         /* just the monitor */
-    double default_display_exponent;   /* whole display system */
-    XEvent e;
-    KeySym k;
-
-
-    displayname = (char *)NULL;
-    filename = (char *)NULL;
-
-
-    /* First set the default value for our display-system exponent, i.e.,
-     * the product of the CRT exponent and the exponent corresponding to
-     * the frame-buffer's lookup table (LUT), if any.  This is not an
-     * exhaustive list of LUT values (e.g., OpenStep has a lot of weird
-     * ones), but it should cover 99% of the current possibilities. */
-
-#if defined(NeXT)
-    LUT_exponent = 1.0 / 2.2;
-    /*
-    if (some_next_function_that_returns_gamma(&next_gamma))
-        LUT_exponent = 1.0 / next_gamma;
-     */
-#elif defined(sgi)
-    LUT_exponent = 1.0 / 1.7;
-    /* there doesn't seem to be any documented function to get the
-     * "gamma" value, so we do it the hard way */
-    infile = fopen("/etc/config/system.glGammaVal", "r");
-    if (infile) {
-        double sgi_gamma;
-
-        fgets(tmpline, 80, infile);
-        fclose(infile);
-        sgi_gamma = atof(tmpline);
-        if (sgi_gamma > 0.0)
-            LUT_exponent = 1.0 / sgi_gamma;
-    }
-#elif defined(Macintosh)
-    LUT_exponent = 1.8 / 2.61;
-    /*
-    if (some_mac_function_that_returns_gamma(&mac_gamma))
-        LUT_exponent = mac_gamma / 2.61;
-     */
-#else
-    LUT_exponent = 1.0;   /* assume no LUT:  most PCs */
-#endif
-
-    /* the defaults above give 1.0, 1.3, 1.5 and 2.2, respectively: */
-    default_display_exponent = LUT_exponent * CRT_exponent;
-
-
-    /* If the user has set the SCREEN_GAMMA environment variable as suggested
-     * (somewhat imprecisely) in the libpng documentation, use that; otherwise
-     * use the default value we just calculated.  Either way, the user may
-     * override this via a command-line option. */
-
-    if ((p = getenv("SCREEN_GAMMA")) != NULL)
-        display_exponent = atof(p);
-    else
-        display_exponent = default_display_exponent;
-
-
-    /* Now parse the command line for options and the PNG filename. */
-
-    while (*++argv && !error) {
-        if (!strncmp(*argv, "-display", 2)) {
-            if (!*++argv)
-                ++error;
-            else
-                displayname = *argv;
-        } else if (!strncmp(*argv, "-gamma", 2)) {
-            if (!*++argv)
-                ++error;
-            else {
-                display_exponent = atof(*argv);
-                if (display_exponent <= 0.0)
-                    ++error;
-            }
-        } else if (!strncmp(*argv, "-bgcolor", 2)) {
-            if (!*++argv)
-                ++error;
-            else {
-                bgstr = *argv;
-                if (strlen(bgstr) != 7 || bgstr[0] != '#')
-                    ++error; 
-                else 
-                    have_bg = TRUE;
-            }
-        } else {
-            if (**argv != '-') {
-                filename = *argv;
-                if (argv[1])   /* shouldn't be any more args after filename */
-                    ++error;
-            } else
-                ++error;   /* not expecting any other options */
-        }
-    }
-
-    if (!filename)
-        ++error;
-
-
-    /* print usage screen if any errors up to this point */
-
-    if (error) {
-        fprintf(stderr, "\n%s %s:  %s\n", PROGNAME, VERSION, appname);
-        readpng_version_info();
-        fprintf(stderr, "\n"
-          "Usage:  %s [-display xdpy] [-gamma exp] [-bgcolor bg] file.png\n"
-          "    xdpy\tname of the target X display (e.g., ``hostname:0'')\n"
-          "    exp \ttransfer-function exponent (``gamma'') of the display\n"
-          "\t\t  system in floating-point format (e.g., ``%.1f''); equal\n"
-          "\t\t  to the product of the lookup-table exponent (varies)\n"
-          "\t\t  and the CRT exponent (usually 2.2); must be positive\n"
-          "    bg  \tdesired background color in 7-character hex RGB format\n"
-          "\t\t  (e.g., ``#ff7700'' for orange:  same as HTML colors);\n"
-          "\t\t  used with transparent images\n"
-          "\nPress Q, Esc or mouse button 1 (within image window, after image\n"
-          "is displayed) to quit.\n"
-          "\n", PROGNAME, default_display_exponent);
-        exit(1);
-    }
-
-
-    if (!(infile = fopen(filename, "rb"))) {
-        fprintf(stderr, PROGNAME ":  can't open PNG file [%s]\n", filename);
-        ++error;
-    } else {
-        if ((rc = readpng_init(infile, &image_width, &image_height)) != 0) {
-            switch (rc) {
-                case 1:
-                    fprintf(stderr, PROGNAME
-                      ":  [%s] is not a PNG file: incorrect signature\n",
-                      filename);
-                    break;
-                case 2:
-                    fprintf(stderr, PROGNAME
-                      ":  [%s] has bad IHDR (libpng longjmp)\n", filename);
-                    break;
-                case 4:
-                    fprintf(stderr, PROGNAME ":  insufficient memory\n");
-                    break;
-                default:
-                    fprintf(stderr, PROGNAME
-                      ":  unknown readpng_init() error\n");
-                    break;
-            }
-            ++error;
-        } else {
-            display = XOpenDisplay(displayname);
-            if (!display) {
-                readpng_cleanup(TRUE);
-                fprintf(stderr, PROGNAME ":  can't open X display [%s]\n",
-                  displayname? displayname : "default");
-                ++error;
-            }
-        }
-        if (error)
-            fclose(infile);
-    }
-
-
-    if (error) {
-        fprintf(stderr, PROGNAME ":  aborting.\n");
-        exit(2);
-    }
-
-
-    /* set the title-bar string, but make sure buffer doesn't overflow */
-
-    alen = strlen(appname);
-    flen = strlen(filename);
-    if (alen + flen + 3 > 1023)
-        sprintf(titlebar, "%s:  ...%s", appname, filename+(alen+flen+6-1023));
-    else
-        sprintf(titlebar, "%s:  %s", appname, filename);
-
-
-    /* if the user didn't specify a background color on the command line,
-     * check for one in the PNG file--if not, the initialized values of 0
-     * (black) will be used */
-
-    if (have_bg) {
-        unsigned r, g, b;   /* this approach quiets compiler warnings */
-
-        sscanf(bgstr+1, "%2x%2x%2x", &r, &g, &b);
-        bg_red   = (uch)r;
-        bg_green = (uch)g;
-        bg_blue  = (uch)b;
-    } else if (readpng_get_bgcolor(&bg_red, &bg_green, &bg_blue) > 1) {
-        readpng_cleanup(TRUE);
-        fprintf(stderr, PROGNAME
-          ":  libpng error while checking for background color\n");
-        exit(2);
-    }
-
-
-    /* do the basic X initialization stuff, make the window and fill it
-     * with the background color */
-
-    if (rpng_x_create_window())
-        exit(2);
-
-
-    /* decode the image, all at once */
-
-    Trace((stderr, "calling readpng_get_image()\n"))
-    image_data = readpng_get_image(display_exponent, &image_channels,
-      &image_rowbytes);
-    Trace((stderr, "done with readpng_get_image()\n"))
-
-
-    /* done with PNG file, so clean up to minimize memory usage (but do NOT
-     * nuke image_data!) */
-
-    readpng_cleanup(FALSE);
-    fclose(infile);
-
-    if (!image_data) {
-        fprintf(stderr, PROGNAME ":  unable to decode PNG image\n");
-        exit(3);
-    }
-
-
-    /* display image (composite with background if requested) */
-
-    Trace((stderr, "calling rpng_x_display_image()\n"))
-    if (rpng_x_display_image()) {
-        free(image_data);
-        exit(4);
-    }
-    Trace((stderr, "done with rpng_x_display_image()\n"))
-
-
-    /* wait for the user to tell us when to quit */
-
-    printf(
-      "Done.  Press Q, Esc or mouse button 1 (within image window) to quit.\n");
-    fflush(stdout);
-
-    do
-        XNextEvent(display, &e);
-    while (!(e.type == ButtonPress && e.xbutton.button == Button1) &&
-           !(e.type == KeyPress &&    /*  v--- or 1 for shifted keys */
-             ((k = XLookupKeysym(&e.xkey, 0)) == XK_q || k == XK_Escape) ));
-
-
-    /* OK, we're done:  clean up all image and X resources and go away */
-
-    rpng_x_cleanup();
-
-    return 0;
-}
-
-
-
-
-
-static int rpng_x_create_window(void)
-{
-    uch *xdata;
-    int need_colormap = FALSE;
-    int screen, pad;
-    ulg bg_pixel = 0L;
-    ulg attrmask;
-    Window root;
-    XEvent e;
-    XGCValues gcvalues;
-    XSetWindowAttributes attr;
-    XTextProperty windowName, *pWindowName = &windowName;
-    XTextProperty iconName, *pIconName = &iconName;
-    XVisualInfo visual_info;
-    XSizeHints *size_hints;
-    XWMHints *wm_hints;
-    XClassHint *class_hints;
-
-
-    screen = DefaultScreen(display);
-    depth = DisplayPlanes(display, screen);
-    root = RootWindow(display, screen);
-
-#ifdef DEBUG
-    XSynchronize(display, True);
-#endif
-
-#if 0
-/* GRR:  add 8-bit support */
-    if (/* depth != 8 && */ depth != 16 && depth != 24 && depth != 32) {
-        fprintf(stderr,
-          "screen depth %d not supported (only 16-, 24- or 32-bit TrueColor)\n",
-          depth);
-        return 2;
-    }
-
-    XMatchVisualInfo(display, screen, depth,
-      (depth == 8)? PseudoColor : TrueColor, &visual_info);
-    visual = visual_info.visual;
-#else
-    if (depth != 16 && depth != 24 && depth != 32) {
-        int visuals_matched = 0;
-
-        Trace((stderr, "default depth is %d:  checking other visuals\n",
-          depth))
-
-        /* 24-bit first */
-        visual_info.screen = screen;
-        visual_info.depth = 24;
-        visual_list = XGetVisualInfo(display,
-          VisualScreenMask | VisualDepthMask, &visual_info, &visuals_matched);
-        if (visuals_matched == 0) {
-/* GRR:  add 15-, 16- and 32-bit TrueColor visuals (also DirectColor?) */
-            fprintf(stderr, "default screen depth %d not supported, and no"
-              " 24-bit visuals found\n", depth);
-            return 2;
-        }
-        Trace((stderr, "XGetVisualInfo() returned %d 24-bit visuals\n",
-          visuals_matched))
-        visual = visual_list[0].visual;
-        depth = visual_list[0].depth;
-/*
-        colormap_size = visual_list[0].colormap_size;
-        visual_class = visual->class;
-        visualID = XVisualIDFromVisual(visual);
- */
-        have_nondefault_visual = TRUE;
-        need_colormap = TRUE;
-    } else {
-        XMatchVisualInfo(display, screen, depth, TrueColor, &visual_info);
-        visual = visual_info.visual;
-    }
-#endif
-
-    RMask = visual->red_mask;
-    GMask = visual->green_mask;
-    BMask = visual->blue_mask;
-
-/* GRR:  add/check 8-bit support */
-    if (depth == 8 || need_colormap) {
-        colormap = XCreateColormap(display, root, visual, AllocNone);
-        if (!colormap) {
-            fprintf(stderr, "XCreateColormap() failed\n");
-            return 2;
-        }
-        have_colormap = TRUE;
-    }
-    if (depth == 15 || depth == 16) {
-        RShift = 15 - rpng_x_msb(RMask);    /* these are right-shifts */
-        GShift = 15 - rpng_x_msb(GMask);
-        BShift = 15 - rpng_x_msb(BMask);
-    } else if (depth > 16) {
-#define NO_24BIT_MASKS
-#ifdef NO_24BIT_MASKS
-        RShift = rpng_x_msb(RMask) - 7;     /* these are left-shifts */
-        GShift = rpng_x_msb(GMask) - 7;
-        BShift = rpng_x_msb(BMask) - 7;
-#else
-        RShift = 7 - rpng_x_msb(RMask);     /* these are right-shifts, too */
-        GShift = 7 - rpng_x_msb(GMask);
-        BShift = 7 - rpng_x_msb(BMask);
-#endif
-    }
-    if (depth >= 15 && (RShift < 0 || GShift < 0 || BShift < 0)) {
-        fprintf(stderr, "rpng internal logic error:  negative X shift(s)!\n");
-        return 2;
-    }
-
-/*---------------------------------------------------------------------------
-    Finally, create the window.
-  ---------------------------------------------------------------------------*/
-
-    attr.backing_store = Always;
-    attr.event_mask = ExposureMask | KeyPressMask | ButtonPressMask;
-    attrmask = CWBackingStore | CWEventMask;
-    if (have_nondefault_visual) {
-        attr.colormap = colormap;
-        attr.background_pixel = 0;
-        attr.border_pixel = 1;
-        attrmask |= CWColormap | CWBackPixel | CWBorderPixel;
-    }
-
-    window = XCreateWindow(display, root, 0, 0, image_width, image_height, 0,
-      depth, InputOutput, visual, attrmask, &attr);
-
-    if (window == None) {
-        fprintf(stderr, "XCreateWindow() failed\n");
-        return 2;
-    } else
-        have_window = TRUE;
-
-    if (depth == 8)
-        XSetWindowColormap(display, window, colormap);
-
-    if (!XStringListToTextProperty(&window_name, 1, pWindowName))
-        pWindowName = NULL;
-    if (!XStringListToTextProperty(&icon_name, 1, pIconName))
-        pIconName = NULL;
-
-    /* OK if any hints allocation fails; XSetWMProperties() allows NULLs */
-
-    if ((size_hints = XAllocSizeHints()) != NULL) {
-        /* window will not be resizable */
-        size_hints->flags = PMinSize | PMaxSize;
-        size_hints->min_width = size_hints->max_width = (int)image_width;
-        size_hints->min_height = size_hints->max_height = (int)image_height;
-    }
-
-    if ((wm_hints = XAllocWMHints()) != NULL) {
-        wm_hints->initial_state = NormalState;
-        wm_hints->input = True;
-     /* wm_hints->icon_pixmap = icon_pixmap; */
-        wm_hints->flags = StateHint | InputHint  /* | IconPixmapHint */ ;
-    }
-
-    if ((class_hints = XAllocClassHint()) != NULL) {
-        class_hints->res_name = res_name;
-        class_hints->res_class = res_class;
-    }
-
-    XSetWMProperties(display, window, pWindowName, pIconName, NULL, 0,
-      size_hints, wm_hints, class_hints);
-
-    /* various properties and hints no longer needed; free memory */
-    if (pWindowName)
-       XFree(pWindowName->value);
-    if (pIconName)
-       XFree(pIconName->value);
-    if (size_hints)
-        XFree(size_hints);
-    if (wm_hints)
-       XFree(wm_hints);
-    if (class_hints)
-       XFree(class_hints);
-
-    XMapWindow(display, window);
-
-    gc = XCreateGC(display, window, 0, &gcvalues);
-    have_gc = TRUE;
-
-/*---------------------------------------------------------------------------
-    Fill window with the specified background color.
-  ---------------------------------------------------------------------------*/
-
-    if (depth == 24 || depth == 32) {
-        bg_pixel = ((ulg)bg_red   << RShift) |
-                   ((ulg)bg_green << GShift) |
-                   ((ulg)bg_blue  << BShift);
-    } else if (depth == 16) {
-        bg_pixel = ((((ulg)bg_red   << 8) >> RShift) & RMask) |
-                   ((((ulg)bg_green << 8) >> GShift) & GMask) |
-                   ((((ulg)bg_blue  << 8) >> BShift) & BMask);
-    } else /* depth == 8 */ {
-
-        /* GRR:  add 8-bit support */
-
-    }
-
-    XSetForeground(display, gc, bg_pixel);
-    XFillRectangle(display, window, gc, 0, 0, image_width, image_height);
-
-/*---------------------------------------------------------------------------
-    Wait for first Expose event to do any drawing, then flush.
-  ---------------------------------------------------------------------------*/
-
-    do
-        XNextEvent(display, &e);
-    while (e.type != Expose || e.xexpose.count);
-
-    XFlush(display);
-
-/*---------------------------------------------------------------------------
-    Allocate memory for the X- and display-specific version of the image.
-  ---------------------------------------------------------------------------*/
-
-    if (depth == 24 || depth == 32) {
-        xdata = (uch *)malloc(4*image_width*image_height);
-        pad = 32;
-    } else if (depth == 16) {
-        xdata = (uch *)malloc(2*image_width*image_height);
-        pad = 16;
-    } else /* depth == 8 */ {
-        xdata = (uch *)malloc(image_width*image_height);
-        pad = 8;
-    }
-
-    if (!xdata) {
-        fprintf(stderr, PROGNAME ":  unable to allocate image memory\n");
-        return 4;
-    }
-
-    ximage = XCreateImage(display, visual, depth, ZPixmap, 0,
-      (char *)xdata, image_width, image_height, pad, 0);
-
-    if (!ximage) {
-        fprintf(stderr, PROGNAME ":  XCreateImage() failed\n");
-        free(xdata);
-        return 3;
-    }
-
-    /* to avoid testing the byte order every pixel (or doubling the size of
-     * the drawing routine with a giant if-test), we arbitrarily set the byte
-     * order to MSBFirst and let Xlib worry about inverting things on little-
-     * endian machines (like Linux/x86, old VAXen, etc.)--this is not the most
-     * efficient approach (the giant if-test would be better), but in the
-     * interest of clarity, we take the easy way out... */
-
-    ximage->byte_order = MSBFirst;
-
-    return 0;
-
-} /* end function rpng_x_create_window() */
-
-
-
-
-
-static int rpng_x_display_image(void)
-{
-    uch *src;
-    char *dest;
-    uch r, g, b, a;
-    ulg i, row, lastrow = 0;
-    ulg pixel;
-    int ximage_rowbytes = ximage->bytes_per_line;
-/*  int bpp = ximage->bits_per_pixel;  */
-
-
-    Trace((stderr, "beginning display loop (image_channels == %d)\n",
-      image_channels))
-    Trace((stderr, "   (width = %ld, rowbytes = %ld, ximage_rowbytes = %d)\n",
-      image_width, image_rowbytes, ximage_rowbytes))
-    Trace((stderr, "   (bpp = %d)\n", ximage->bits_per_pixel))
-    Trace((stderr, "   (byte_order = %s)\n", ximage->byte_order == MSBFirst?
-      "MSBFirst" : (ximage->byte_order == LSBFirst? "LSBFirst" : "unknown")))
-
-    if (depth == 24 || depth == 32) {
-        ulg red, green, blue;
-
-        for (lastrow = row = 0;  row < image_height;  ++row) {
-            src = image_data + row*image_rowbytes;
-            dest = ximage->data + row*ximage_rowbytes;
-            if (image_channels == 3) {
-                for (i = image_width;  i > 0;  --i) {
-                    red   = *src++;
-                    green = *src++;
-                    blue  = *src++;
-#ifdef NO_24BIT_MASKS
-                    pixel = (red   << RShift) |
-                            (green << GShift) |
-                            (blue  << BShift);
-                    /* recall that we set ximage->byte_order = MSBFirst above */
-                    /* GRR BUG:  this assumes bpp == 32, but may be 24: */
-                    *dest++ = (char)((pixel >> 24) & 0xff);
-                    *dest++ = (char)((pixel >> 16) & 0xff);
-                    *dest++ = (char)((pixel >>  8) & 0xff);
-                    *dest++ = (char)( pixel        & 0xff);
-#else
-                    red   = (RShift < 0)? red   << (-RShift) : red   >> RShift;
-                    green = (GShift < 0)? green << (-GShift) : green >> GShift;
-                    blue  = (BShift < 0)? blue  << (-BShift) : blue  >> BShift;
-                    pixel = (red & RMask) | (green & GMask) | (blue & BMask);
-                    /* recall that we set ximage->byte_order = MSBFirst above */
-                    *dest++ = (char)((pixel >> 24) & 0xff);
-                    *dest++ = (char)((pixel >> 16) & 0xff);
-                    *dest++ = (char)((pixel >>  8) & 0xff);
-                    *dest++ = (char)( pixel        & 0xff);
-#endif
-                }
-            } else /* if (image_channels == 4) */ {
-                for (i = image_width;  i > 0;  --i) {
-                    r = *src++;
-                    g = *src++;
-                    b = *src++;
-                    a = *src++;
-                    if (a == 255) {
-                        red   = r;
-                        green = g;
-                        blue  = b;
-                    } else if (a == 0) {
-                        red   = bg_red;
-                        green = bg_green;
-                        blue  = bg_blue;
-                    } else {
-                        /* this macro (from png.h) composites the foreground
-                         * and background values and puts the result into the
-                         * first argument */
-                        alpha_composite(red,   r, a, bg_red);
-                        alpha_composite(green, g, a, bg_green);
-                        alpha_composite(blue,  b, a, bg_blue);
-                    }
-                    pixel = (red   << RShift) |
-                            (green << GShift) |
-                            (blue  << BShift);
-                    /* recall that we set ximage->byte_order = MSBFirst above */
-                    *dest++ = (char)((pixel >> 24) & 0xff);
-                    *dest++ = (char)((pixel >> 16) & 0xff);
-                    *dest++ = (char)((pixel >>  8) & 0xff);
-                    *dest++ = (char)( pixel        & 0xff);
-                }
-            }
-            /* display after every 16 lines */
-            if (((row+1) & 0xf) == 0) {
-                XPutImage(display, window, gc, ximage, 0, (int)lastrow, 0,
-                  (int)lastrow, image_width, 16);
-                XFlush(display);
-                lastrow = row + 1;
-            }
-        }
-
-    } else if (depth == 16) {
-        ush red, green, blue;
-
-        for (lastrow = row = 0;  row < image_height;  ++row) {
-            src = image_data + row*image_rowbytes;
-            dest = ximage->data + row*ximage_rowbytes;
-            if (image_channels == 3) {
-                for (i = image_width;  i > 0;  --i) {
-                    red   = ((ush)(*src) << 8);
-                    ++src;
-                    green = ((ush)(*src) << 8);
-                    ++src;
-                    blue  = ((ush)(*src) << 8);
-                    ++src;
-                    pixel = ((red   >> RShift) & RMask) |
-                            ((green >> GShift) & GMask) |
-                            ((blue  >> BShift) & BMask);
-                    /* recall that we set ximage->byte_order = MSBFirst above */
-                    *dest++ = (char)((pixel >>  8) & 0xff);
-                    *dest++ = (char)( pixel        & 0xff);
-                }
-            } else /* if (image_channels == 4) */ {
-                for (i = image_width;  i > 0;  --i) {
-                    r = *src++;
-                    g = *src++;
-                    b = *src++;
-                    a = *src++;
-                    if (a == 255) {
-                        red   = ((ush)r << 8);
-                        green = ((ush)g << 8);
-                        blue  = ((ush)b << 8);
-                    } else if (a == 0) {
-                        red   = ((ush)bg_red   << 8);
-                        green = ((ush)bg_green << 8);
-                        blue  = ((ush)bg_blue  << 8);
-                    } else {
-                        /* this macro (from png.h) composites the foreground
-                         * and background values and puts the result back into
-                         * the first argument (== fg byte here:  safe) */
-                        alpha_composite(r, r, a, bg_red);
-                        alpha_composite(g, g, a, bg_green);
-                        alpha_composite(b, b, a, bg_blue);
-                        red   = ((ush)r << 8);
-                        green = ((ush)g << 8);
-                        blue  = ((ush)b << 8);
-                    }
-                    pixel = ((red   >> RShift) & RMask) |
-                            ((green >> GShift) & GMask) |
-                            ((blue  >> BShift) & BMask);
-                    /* recall that we set ximage->byte_order = MSBFirst above */
-                    *dest++ = (char)((pixel >>  8) & 0xff);
-                    *dest++ = (char)( pixel        & 0xff);
-                }
-            }
-            /* display after every 16 lines */
-            if (((row+1) & 0xf) == 0) {
-                XPutImage(display, window, gc, ximage, 0, (int)lastrow, 0,
-                  (int)lastrow, image_width, 16);
-                XFlush(display);
-                lastrow = row + 1;
-            }
-        }
-
-    } else /* depth == 8 */ {
-
-        /* GRR:  add 8-bit support */
-
-    }
-
-    Trace((stderr, "calling final XPutImage()\n"))
-    if (lastrow < image_height) {
-        XPutImage(display, window, gc, ximage, 0, (int)lastrow, 0,
-          (int)lastrow, image_width, image_height-lastrow);
-        XFlush(display);
-    }
-
-    return 0;
-}
-
-
-
-
-static void rpng_x_cleanup(void)
-{
-    if (image_data) {
-        free(image_data);
-        image_data = NULL;
-    }
-
-    if (ximage) {
-        if (ximage->data) {
-            free(ximage->data);           /* we allocated it, so we free it */
-            ximage->data = (char *)NULL;  /*  instead of XDestroyImage() */
-        }
-        XDestroyImage(ximage);
-        ximage = NULL;
-    }
-
-    if (have_gc)
-        XFreeGC(display, gc);
-
-    if (have_window)
-        XDestroyWindow(display, window);
-
-    if (have_colormap)
-        XFreeColormap(display, colormap);
-
-    if (have_nondefault_visual)
-        XFree(visual_list);
-}
-
-
-
-
-
-static int rpng_x_msb(ulg u32val)
-{
-    int i;
-
-    for (i = 31;  i >= 0;  --i) {
-        if (u32val & 0x80000000L)
-            break;
-        u32val <<= 1;
-    }
-    return i;
-}
diff --git a/contrib/gregbook/rpng2-win.c b/contrib/gregbook/rpng2-win.c
deleted file mode 100644
index 9f7ad78..0000000
--- a/contrib/gregbook/rpng2-win.c
+++ /dev/null
@@ -1,1225 +0,0 @@
-/*---------------------------------------------------------------------------
-
-   rpng2 - progressive-model PNG display program                rpng2-win.c
-
-   This program decodes and displays PNG files progressively, as if it were
-   a web browser (though the front end is only set up to read from files).
-   It supports gamma correction, user-specified background colors, and user-
-   specified background patterns (for transparent images).  This version is
-   for 32-bit Windows; it may compile under 16-bit Windows with a little
-   tweaking (or maybe not).  Thanks to Adam Costello and Pieter S. van der
-   Meulen for the "diamond" and "radial waves" patterns, respectively.
-
-   to do (someday, maybe):
-    - handle quoted command-line args (especially filenames with spaces)
-    - finish resizable checkerboard-gradient (sizes 4-128?)
-    - use %.1023s to simplify truncation of title-bar string?
-    - have minimum window width:  oh well
-
-  ---------------------------------------------------------------------------
-
-   Changelog:
-    - 1.01:  initial public release
-    - 1.02:  fixed cut-and-paste error in usage screen (oops...)
-    - 1.03:  modified to allow abbreviated options
-    - 1.04:  removed bogus extra argument from usage fprintf() [Glenn R-P?];
-              fixed command-line parsing bug
-    - 1.10:  enabled "message window"/console (thanks to David Geldreich)
-    - 1.20:  added runtime MMX-enabling/disabling and new -mmx* options
-    - 1.21:  made minor tweak to usage screen to fit within 25-line console
-    - 1.22:  added AMD64/EM64T support (__x86_64__)
-    - 2.00:  dual-licensed (added GNU GPL)
-    - 2.01:  fixed 64-bit typo in readpng2.c
-    - 2.02:  fixed improper display of usage screen on PNG error(s); fixed
-              unexpected-EOF and file-read-error cases
-
-  ---------------------------------------------------------------------------
-
-      Copyright (c) 1998-2008 Greg Roelofs.  All rights reserved.
-
-      This software is provided "as is," without warranty of any kind,
-      express or implied.  In no event shall the author or contributors
-      be held liable for any damages arising in any way from the use of
-      this software.
-
-      The contents of this file are DUAL-LICENSED.  You may modify and/or
-      redistribute this software according to the terms of one of the
-      following two licenses (at your option):
-
-
-      LICENSE 1 ("BSD-like with advertising clause"):
-
-      Permission is granted to anyone to use this software for any purpose,
-      including commercial applications, and to alter it and redistribute
-      it freely, subject to the following restrictions:
-
-      1. Redistributions of source code must retain the above copyright
-         notice, disclaimer, and this list of conditions.
-      2. Redistributions in binary form must reproduce the above copyright
-         notice, disclaimer, and this list of conditions in the documenta-
-         tion and/or other materials provided with the distribution.
-      3. All advertising materials mentioning features or use of this
-         software must display the following acknowledgment:
-
-            This product includes software developed by Greg Roelofs
-            and contributors for the book, "PNG: The Definitive Guide,"
-            published by O'Reilly and Associates.
-
-
-      LICENSE 2 (GNU GPL v2 or later):
-
-      This program is free software; you can redistribute it and/or modify
-      it under the terms of the GNU General Public License as published by
-      the Free Software Foundation; either version 2 of the License, or
-      (at your option) any later version.
-
-      This program is distributed in the hope that it will be useful,
-      but WITHOUT ANY WARRANTY; without even the implied warranty of
-      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-      GNU General Public License for more details.
-
-      You should have received a copy of the GNU General Public License
-      along with this program; if not, write to the Free Software Foundation,
-      Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
-
-  ---------------------------------------------------------------------------*/
-
-#define PROGNAME  "rpng2-win"
-#define LONGNAME  "Progressive PNG Viewer for Windows"
-#define VERSION   "2.02 of 16 March 2008"
-
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <setjmp.h>    /* for jmpbuf declaration in readpng2.h */
-#include <time.h>
-#include <math.h>      /* only for PvdM background code */
-#include <windows.h>
-#include <conio.h>     /* only for _getch() */
-
-/* all for PvdM background code: */
-#ifndef PI
-#  define PI             3.141592653589793238
-#endif
-#define PI_2             (PI*0.5)
-#define INV_PI_360       (360.0 / PI)
-#define MAX(a,b)         (a>b?a:b)
-#define MIN(a,b)         (a<b?a:b)
-#define CLIP(a,min,max)  MAX(min,MIN((a),max))
-#define ABS(a)           ((a)<0?-(a):(a))
-#define CLIP8P(c)        MAX(0,(MIN((c),255)))   /* 8-bit pos. integer (uch) */
-#define ROUNDF(f)        ((int)(f + 0.5))
-
-#define rgb1_max   bg_freq
-#define rgb1_min   bg_gray
-#define rgb2_max   bg_bsat
-#define rgb2_min   bg_brot
-
-/* #define DEBUG */     /* this enables the Trace() macros */
-
-#include "readpng2.h"   /* typedefs, common macros, readpng2 prototypes */
-
-
-/* could just include png.h, but this macro is the only thing we need
- * (name and typedefs changed to local versions); note that side effects
- * only happen with alpha (which could easily be avoided with
- * "ush acopy = (alpha);") */
-
-#define alpha_composite(composite, fg, alpha, bg) {               \
-    ush temp = ((ush)(fg)*(ush)(alpha) +                          \
-                (ush)(bg)*(ush)(255 - (ush)(alpha)) + (ush)128);  \
-    (composite) = (uch)((temp + (temp >> 8)) >> 8);               \
-}
-
-
-#define INBUFSIZE 4096   /* with pseudo-timing on (1 sec delay/block), this
-                          *  block size corresponds roughly to a download
-                          *  speed 10% faster than theoretical 33.6K maximum
-                          *  (assuming 8 data bits, 1 stop bit and no other
-                          *  overhead) */
-
-/* local prototypes */
-static void       rpng2_win_init(void);
-static int        rpng2_win_create_window(void);
-static int        rpng2_win_load_bg_image(void);
-static void       rpng2_win_display_row(ulg row);
-static void       rpng2_win_finish_display(void);
-static void       rpng2_win_cleanup(void);
-LRESULT CALLBACK  rpng2_win_wndproc(HWND, UINT, WPARAM, LPARAM);
-
-
-static char titlebar[1024];
-static char *progname = PROGNAME;
-static char *appname = LONGNAME;
-static char *filename;
-static FILE *infile;
-
-static mainprog_info rpng2_info;
-
-static uch inbuf[INBUFSIZE];
-static int incount;
-
-static int pat = 6;         /* must be less than num_bgpat */
-static int bg_image = 0;
-static int bgscale = 16;
-static ulg bg_rowbytes;
-static uch *bg_data;
-
-static struct rgb_color {
-    uch r, g, b;
-} rgb[] = {
-    {  0,   0,   0},    /*  0:  black */
-    {255, 255, 255},    /*  1:  white */
-    {173, 132,  57},    /*  2:  tan */
-    { 64, 132,   0},    /*  3:  medium green */
-    {189, 117,   1},    /*  4:  gold */
-    {253, 249,   1},    /*  5:  yellow */
-    {  0,   0, 255},    /*  6:  blue */
-    {  0,   0, 120},    /*  7:  medium blue */
-    {255,   0, 255},    /*  8:  magenta */
-    { 64,   0,  64},    /*  9:  dark magenta */
-    {255,   0,   0},    /* 10:  red */
-    { 64,   0,   0},    /* 11:  dark red */
-    {255, 127,   0},    /* 12:  orange */
-    {192,  96,   0},    /* 13:  darker orange */
-    { 24,  60,   0},    /* 14:  dark green-yellow */
-    { 85, 125, 200}     /* 15:  ice blue */
-};
-/* not used for now, but should be for error-checking:
-static int num_rgb = sizeof(rgb) / sizeof(struct rgb_color);
- */
-
-/*
-    This whole struct is a fairly cheesy way to keep the number of
-    command-line options to a minimum.  The radial-waves background
-    type is a particularly poor fit to the integer elements of the
-    struct...but a few macros and a little fixed-point math will do
-    wonders for ya.
-
-    type bits:
-       F E D C B A 9 8 7 6 5 4 3 2 1 0
-                             | | | | |
-                             | | +-+-+-- 0 = sharp-edged checkerboard
-                             | |         1 = soft diamonds
-                             | |         2 = radial waves
-                             | |       3-7 = undefined
-                             | +-- gradient #2 inverted?
-                             +-- alternating columns inverted?
- */
-static struct background_pattern {
-    ush type;
-    int rgb1_max, rgb1_min;     /* or bg_freq, bg_gray */
-    int rgb2_max, rgb2_min;     /* or bg_bsat, bg_brot (both scaled by 10)*/
-} bg[] = {
-    {0+8,   2,0,  1,15},        /* checkered:  tan/black vs. white/ice blue */
-    {0+24,  2,0,  1,0},         /* checkered:  tan/black vs. white/black */
-    {0+8,   4,5,  0,2},         /* checkered:  gold/yellow vs. black/tan */
-    {0+8,   4,5,  0,6},         /* checkered:  gold/yellow vs. black/blue */
-    {0,     7,0,  8,9},         /* checkered:  deep blue/black vs. magenta */
-    {0+8,  13,0,  5,14},        /* checkered:  orange/black vs. yellow */
-    {0+8,  12,0, 10,11},        /* checkered:  orange/black vs. red */
-    {1,     7,0,  8,0},         /* diamonds:  deep blue/black vs. magenta */
-    {1,    12,0, 11,0},         /* diamonds:  orange vs. dark red */
-    {1,    10,0,  7,0},         /* diamonds:  red vs. medium blue */
-    {1,     4,0,  5,0},         /* diamonds:  gold vs. yellow */
-    {1,     3,0,  0,0},         /* diamonds:  medium green vs. black */
-    {2,    16, 100,  20,   0},  /* radial:  ~hard radial color-beams */
-    {2,    18, 100,  10,   2},  /* radial:  soft, curved radial color-beams */
-    {2,    16, 256, 100, 250},  /* radial:  very tight spiral */
-    {2, 10000, 256,  11,   0}   /* radial:  dipole-moire' (almost fractal) */
-};
-static int num_bgpat = sizeof(bg) / sizeof(struct background_pattern);
-
-
-/* Windows-specific global variables (could go in struct, but messy...) */
-static ulg wimage_rowbytes;
-static uch *dib;
-static uch *wimage_data;
-static BITMAPINFOHEADER *bmih;
-
-static HWND global_hwnd;
-static HINSTANCE global_hInst;
-static int global_showmode;
-
-
-
-
-int WINAPI WinMain(HINSTANCE hInst, HINSTANCE hPrevInst, PSTR cmd, int showmode)
-{
-    char *args[1024];                 /* arbitrary limit, but should suffice */
-    char **argv = args;
-    char *p, *q, *bgstr = NULL;
-    int argc = 0;
-    int rc, alen, flen;
-    int error = 0;
-    int timing = FALSE;
-    int have_bg = FALSE;
-    double LUT_exponent;              /* just the lookup table */
-    double CRT_exponent = 2.2;        /* just the monitor */
-    double default_display_exponent;  /* whole display system */
-    MSG msg;
-
-
-    /* First initialize a few things, just to be sure--memset takes care of
-     * default background color (black), booleans (FALSE), pointers (NULL),
-     * etc. */
-
-    global_hInst = hInst;
-    global_showmode = showmode;
-    filename = (char *)NULL;
-    memset(&rpng2_info, 0, sizeof(mainprog_info));
-
-
-    /* Next reenable console output, which normally goes to the bit bucket
-     * for windowed apps.  Closing the console window will terminate the
-     * app.  Thanks to David.Geldreich@realviz.com for supplying the magical
-     * incantation. */
-
-    AllocConsole();
-    freopen("CONOUT$", "a", stderr);
-    freopen("CONOUT$", "a", stdout);
-
-
-    /* Set the default value for our display-system exponent, i.e., the
-     * product of the CRT exponent and the exponent corresponding to
-     * the frame-buffer's lookup table (LUT), if any.  This is not an
-     * exhaustive list of LUT values (e.g., OpenStep has a lot of weird
-     * ones), but it should cover 99% of the current possibilities.  And
-     * yes, these ifdefs are completely wasted in a Windows program... */
-
-#if defined(NeXT)
-    /* third-party utilities can modify the default LUT exponent */
-    LUT_exponent = 1.0 / 2.2;
-    /*
-    if (some_next_function_that_returns_gamma(&next_gamma))
-        LUT_exponent = 1.0 / next_gamma;
-     */
-#elif defined(sgi)
-    LUT_exponent = 1.0 / 1.7;
-    /* there doesn't seem to be any documented function to
-     * get the "gamma" value, so we do it the hard way */
-    infile = fopen("/etc/config/system.glGammaVal", "r");
-    if (infile) {
-        double sgi_gamma;
-
-        fgets(tmpline, 80, infile);
-        fclose(infile);
-        sgi_gamma = atof(tmpline);
-        if (sgi_gamma > 0.0)
-            LUT_exponent = 1.0 / sgi_gamma;
-    }
-#elif defined(Macintosh)
-    LUT_exponent = 1.8 / 2.61;
-    /*
-    if (some_mac_function_that_returns_gamma(&mac_gamma))
-        LUT_exponent = mac_gamma / 2.61;
-     */
-#else
-    LUT_exponent = 1.0;   /* assume no LUT:  most PCs */
-#endif
-
-    /* the defaults above give 1.0, 1.3, 1.5 and 2.2, respectively: */
-    default_display_exponent = LUT_exponent * CRT_exponent;
-
-
-    /* If the user has set the SCREEN_GAMMA environment variable as suggested
-     * (somewhat imprecisely) in the libpng documentation, use that; otherwise
-     * use the default value we just calculated.  Either way, the user may
-     * override this via a command-line option. */
-
-    if ((p = getenv("SCREEN_GAMMA")) != NULL)
-        rpng2_info.display_exponent = atof(p);
-    else
-        rpng2_info.display_exponent = default_display_exponent;
-
-
-    /* Windows really hates command lines, so we have to set up our own argv.
-     * Note that we do NOT bother with quoted arguments here, so don't use
-     * filenames with spaces in 'em! */
-
-    argv[argc++] = PROGNAME;
-    p = cmd;
-    for (;;) {
-        if (*p == ' ')
-            while (*++p == ' ')
-                ;
-        /* now p points at the first non-space after some spaces */
-        if (*p == '\0')
-            break;    /* nothing after the spaces:  done */
-        argv[argc++] = q = p;
-        while (*q && *q != ' ')
-            ++q;
-        /* now q points at a space or the end of the string */
-        if (*q == '\0')
-            break;    /* last argv already terminated; quit */
-        *q = '\0';    /* change space to terminator */
-        p = q + 1;
-    }
-    argv[argc] = NULL;   /* terminate the argv array itself */
-
-
-    /* Now parse the command line for options and the PNG filename. */
-
-    while (*++argv && !error) {
-        if (!strncmp(*argv, "-gamma", 2)) {
-            if (!*++argv)
-                ++error;
-            else {
-                rpng2_info.display_exponent = atof(*argv);
-                if (rpng2_info.display_exponent <= 0.0)
-                    ++error;
-            }
-        } else if (!strncmp(*argv, "-bgcolor", 4)) {
-            if (!*++argv)
-                ++error;
-            else {
-                bgstr = *argv;
-                if (strlen(bgstr) != 7 || bgstr[0] != '#')
-                    ++error;
-                else {
-                    have_bg = TRUE;
-                    bg_image = FALSE;
-                }
-            }
-        } else if (!strncmp(*argv, "-bgpat", 4)) {
-            if (!*++argv)
-                ++error;
-            else {
-                pat = atoi(*argv) - 1;
-                if (pat < 0 || pat >= num_bgpat)
-                    ++error;
-                else {
-                    bg_image = TRUE;
-                    have_bg = FALSE;
-                }
-            }
-        } else if (!strncmp(*argv, "-timing", 2)) {
-            timing = TRUE;
-#if (defined(__i386__) || defined(_M_IX86) || defined(__x86_64__))
-        } else if (!strncmp(*argv, "-nommxfilters", 7)) {
-            rpng2_info.nommxfilters = TRUE;
-        } else if (!strncmp(*argv, "-nommxcombine", 7)) {
-            rpng2_info.nommxcombine = TRUE;
-        } else if (!strncmp(*argv, "-nommxinterlace", 7)) {
-            rpng2_info.nommxinterlace = TRUE;
-        } else if (!strcmp(*argv, "-nommx")) {
-            rpng2_info.nommxfilters = TRUE;
-            rpng2_info.nommxcombine = TRUE;
-            rpng2_info.nommxinterlace = TRUE;
-#endif
-        } else {
-            if (**argv != '-') {
-                filename = *argv;
-                if (argv[1])   /* shouldn't be any more args after filename */
-                    ++error;
-            } else
-                ++error;   /* not expecting any other options */
-        }
-    }
-
-    if (!filename)
-        ++error;
-
-
-    /* print usage screen if any errors up to this point */
-
-    if (error) {
-        int ch;
-
-        fprintf(stderr, "\n%s %s:  %s\n\n", PROGNAME, VERSION, appname);
-        readpng2_version_info();
-        fprintf(stderr, "\n"
-          "Usage:  %s [-gamma exp] [-bgcolor bg | -bgpat pat] [-timing]\n"
-#if (defined(__i386__) || defined(_M_IX86) || defined(__x86_64__))
-          "        %*s [[-nommxfilters] [-nommxcombine] [-nommxinterlace] | -nommx]\n"
-#endif
-          "        %*s file.png\n\n"
-          "    exp \ttransfer-function exponent (``gamma'') of the display\n"
-          "\t\t  system in floating-point format (e.g., ``%.1f''); equal\n"
-          "\t\t  to the product of the lookup-table exponent (varies)\n"
-          "\t\t  and the CRT exponent (usually 2.2); must be positive\n"
-          "    bg  \tdesired background color in 7-character hex RGB format\n"
-          "\t\t  (e.g., ``#ff7700'' for orange:  same as HTML colors);\n"
-          "\t\t  used with transparent images; overrides -bgpat option\n"
-          "    pat \tdesired background pattern number (1-%d); used with\n"
-          "\t\t  transparent images; overrides -bgcolor option\n"
-          "    -timing\tenables delay for every block read, to simulate modem\n"
-          "\t\t  download of image (~36 Kbps)\n"
-#if (defined(__i386__) || defined(_M_IX86) || defined(__x86_64__))
-          "    -nommx*\tdisable optimized MMX routines for decoding row filters,\n"
-          "\t\t  combining rows, and expanding interlacing, respectively\n"
-#endif
-          "\nPress Q, Esc or mouse button 1 after image is displayed to quit.\n"
-          "Press Q or Esc to quit this usage screen. ",
-          PROGNAME,
-#if (defined(__i386__) || defined(_M_IX86) || defined(__x86_64__))
-          (int)strlen(PROGNAME), " ",
-#endif
-          (int)strlen(PROGNAME), " ", default_display_exponent, num_bgpat);
-        fflush(stderr);
-        do
-            ch = _getch();
-        while (ch != 'q' && ch != 'Q' && ch != 0x1B);
-        exit(1);
-    }
-
-
-    if (!(infile = fopen(filename, "rb"))) {
-        fprintf(stderr, PROGNAME ":  can't open PNG file [%s]\n", filename);
-        ++error;
-    } else {
-        incount = fread(inbuf, 1, INBUFSIZE, infile);
-        if (incount < 8 || !readpng2_check_sig(inbuf, 8)) {
-            fprintf(stderr, PROGNAME
-              ":  [%s] is not a PNG file: incorrect signature\n",
-              filename);
-            ++error;
-        } else if ((rc = readpng2_init(&rpng2_info)) != 0) {
-            switch (rc) {
-                case 2:
-                    fprintf(stderr, PROGNAME
-                      ":  [%s] has bad IHDR (libpng longjmp)\n", filename);
-                    break;
-                case 4:
-                    fprintf(stderr, PROGNAME ":  insufficient memory\n");
-                    break;
-                default:
-                    fprintf(stderr, PROGNAME
-                      ":  unknown readpng2_init() error\n");
-                    break;
-            }
-            ++error;
-        }
-        if (error)
-            fclose(infile);
-    }
-
-
-    if (error) {
-        int ch;
-
-        fprintf(stderr, PROGNAME ":  aborting.\n");
-        do
-            ch = _getch();
-        while (ch != 'q' && ch != 'Q' && ch != 0x1B);
-        exit(2);
-    } else {
-        fprintf(stderr, "\n%s %s:  %s\n", PROGNAME, VERSION, appname);
-        fprintf(stderr,
-          "\n   [console window:  closing this window will terminate %s]\n\n",
-          PROGNAME);
-        fflush(stderr);
-    }
-
-
-    /* set the title-bar string, but make sure buffer doesn't overflow */
-
-    alen = strlen(appname);
-    flen = strlen(filename);
-    if (alen + flen + 3 > 1023)
-        sprintf(titlebar, "%s:  ...%s", appname, filename+(alen+flen+6-1023));
-    else
-        sprintf(titlebar, "%s:  %s", appname, filename);
-
-
-    /* set some final rpng2_info variables before entering main data loop */
-
-    if (have_bg) {
-        unsigned r, g, b;   /* this approach quiets compiler warnings */
-
-        sscanf(bgstr+1, "%2x%2x%2x", &r, &g, &b);
-        rpng2_info.bg_red   = (uch)r;
-        rpng2_info.bg_green = (uch)g;
-        rpng2_info.bg_blue  = (uch)b;
-    } else
-        rpng2_info.need_bgcolor = TRUE;
-
-    rpng2_info.state = kPreInit;
-    rpng2_info.mainprog_init = rpng2_win_init;
-    rpng2_info.mainprog_display_row = rpng2_win_display_row;
-    rpng2_info.mainprog_finish_display = rpng2_win_finish_display;
-
-
-    /* OK, this is the fun part:  call readpng2_decode_data() at the start of
-     * the loop to deal with our first buffer of data (read in above to verify
-     * that the file is a PNG image), then loop through the file and continue
-     * calling the same routine to handle each chunk of data.  It in turn
-     * passes the data to libpng, which will invoke one or more of our call-
-     * backs as decoded data become available.  We optionally call Sleep() for
-     * one second per iteration to simulate downloading the image via an analog
-     * modem. */
-
-    for (;;) {
-        Trace((stderr, "about to call readpng2_decode_data()\n"))
-        if (readpng2_decode_data(&rpng2_info, inbuf, incount))
-            ++error;
-        Trace((stderr, "done with readpng2_decode_data()\n"))
-
-        if (error || incount != INBUFSIZE || rpng2_info.state == kDone) {
-            if (rpng2_info.state == kDone) {
-                Trace((stderr, "done decoding PNG image\n"))
-            } else if (ferror(infile)) {
-                fprintf(stderr, PROGNAME
-                  ":  error while reading PNG image file\n");
-                exit(3);
-            } else if (feof(infile)) {
-                fprintf(stderr, PROGNAME ":  end of file reached "
-                  "(unexpectedly) while reading PNG image file\n");
-                exit(3);
-            } else /* if (error) */ {
-                // will print error message below
-            }
-            break;
-        }
-
-        if (timing)
-            Sleep(1000L);
-
-        incount = fread(inbuf, 1, INBUFSIZE, infile);
-    }
-
-
-    /* clean up PNG stuff and report any decoding errors */
-
-    fclose(infile);
-    Trace((stderr, "about to call readpng2_cleanup()\n"))
-    readpng2_cleanup(&rpng2_info);
-
-    if (error) {
-        fprintf(stderr, PROGNAME ":  libpng error while decoding PNG image\n");
-        exit(3);
-    }
-
-
-    /* wait for the user to tell us when to quit */
-
-    while (GetMessage(&msg, NULL, 0, 0)) {
-        TranslateMessage(&msg);
-        DispatchMessage(&msg);
-    }
-
-
-    /* we're done:  clean up all image and Windows resources and go away */
-
-    Trace((stderr, "about to call rpng2_win_cleanup()\n"))
-    rpng2_win_cleanup();
-
-    return msg.wParam;
-}
-
-
-
-
-
-/* this function is called by readpng2_info_callback() in readpng2.c, which
- * in turn is called by libpng after all of the pre-IDAT chunks have been
- * read and processed--i.e., we now have enough info to finish initializing */
-
-static void rpng2_win_init()
-{
-    ulg i;
-    ulg rowbytes = rpng2_info.rowbytes;
-
-    Trace((stderr, "beginning rpng2_win_init()\n"))
-    Trace((stderr, "  rowbytes = %d\n", rpng2_info.rowbytes))
-    Trace((stderr, "  width  = %ld\n", rpng2_info.width))
-    Trace((stderr, "  height = %ld\n", rpng2_info.height))
-
-    rpng2_info.image_data = (uch *)malloc(rowbytes * rpng2_info.height);
-    if (!rpng2_info.image_data) {
-        readpng2_cleanup(&rpng2_info);
-        return;
-    }
-
-    rpng2_info.row_pointers = (uch **)malloc(rpng2_info.height * sizeof(uch *));
-    if (!rpng2_info.row_pointers) {
-        free(rpng2_info.image_data);
-        rpng2_info.image_data = NULL;
-        readpng2_cleanup(&rpng2_info);
-        return;
-    }
-
-    for (i = 0;  i < rpng2_info.height;  ++i)
-        rpng2_info.row_pointers[i] = rpng2_info.image_data + i*rowbytes;
-
-/*---------------------------------------------------------------------------
-    Do the basic Windows initialization stuff, make the window, and fill it
-    with the user-specified, file-specified or default background color.
-  ---------------------------------------------------------------------------*/
-
-    if (rpng2_win_create_window()) {
-        readpng2_cleanup(&rpng2_info);
-        return;
-    }
-
-    rpng2_info.state = kWindowInit;
-}
-
-
-
-
-
-static int rpng2_win_create_window()
-{
-    uch bg_red   = rpng2_info.bg_red;
-    uch bg_green = rpng2_info.bg_green;
-    uch bg_blue  = rpng2_info.bg_blue;
-    uch *dest;
-    int extra_width, extra_height;
-    ulg i, j;
-    WNDCLASSEX wndclass;
-    RECT rect;
-
-
-/*---------------------------------------------------------------------------
-    Allocate memory for the display-specific version of the image (round up
-    to multiple of 4 for Windows DIB).
-  ---------------------------------------------------------------------------*/
-
-    wimage_rowbytes = ((3*rpng2_info.width + 3L) >> 2) << 2;
-
-    if (!(dib = (uch *)malloc(sizeof(BITMAPINFOHEADER) +
-                              wimage_rowbytes*rpng2_info.height)))
-    {
-        return 4;   /* fail */
-    }
-
-/*---------------------------------------------------------------------------
-    Initialize the DIB.  Negative height means to use top-down BMP ordering
-    (must be uncompressed, but that's what we want).  Bit count of 1, 4 or 8
-    implies a colormap of RGBX quads, but 24-bit BMPs just use B,G,R values
-    directly => wimage_data begins immediately after BMP header.
-  ---------------------------------------------------------------------------*/
-
-    memset(dib, 0, sizeof(BITMAPINFOHEADER));
-    bmih = (BITMAPINFOHEADER *)dib;
-    bmih->biSize = sizeof(BITMAPINFOHEADER);
-    bmih->biWidth = rpng2_info.width;
-    bmih->biHeight = -((long)rpng2_info.height);
-    bmih->biPlanes = 1;
-    bmih->biBitCount = 24;
-    bmih->biCompression = 0;
-    wimage_data = dib + sizeof(BITMAPINFOHEADER);
-
-/*---------------------------------------------------------------------------
-    Fill window with the specified background color (default is black), but
-    defer loading faked "background image" until window is displayed (may be
-    slow to compute).  Data are in BGR order.
-  ---------------------------------------------------------------------------*/
-
-    if (bg_image) {   /* just fill with black for now */
-        memset(wimage_data, 0, wimage_rowbytes*rpng2_info.height);
-    } else {
-        for (j = 0;  j < rpng2_info.height;  ++j) {
-            dest = wimage_data + j*wimage_rowbytes;
-            for (i = rpng2_info.width;  i > 0;  --i) {
-                *dest++ = bg_blue;
-                *dest++ = bg_green;
-                *dest++ = bg_red;
-            }
-        }
-    }
-
-/*---------------------------------------------------------------------------
-    Set the window parameters.
-  ---------------------------------------------------------------------------*/
-
-    memset(&wndclass, 0, sizeof(wndclass));
-
-    wndclass.cbSize = sizeof(wndclass);
-    wndclass.style = CS_HREDRAW | CS_VREDRAW;
-    wndclass.lpfnWndProc = rpng2_win_wndproc;
-    wndclass.hInstance = global_hInst;
-    wndclass.hIcon = LoadIcon(NULL, IDI_APPLICATION);
-    wndclass.hCursor = LoadCursor(NULL, IDC_ARROW);
-    wndclass.hbrBackground = (HBRUSH)GetStockObject(DKGRAY_BRUSH);
-    wndclass.lpszMenuName = NULL;
-    wndclass.lpszClassName = progname;
-    wndclass.hIconSm = LoadIcon(NULL, IDI_APPLICATION);
-
-    RegisterClassEx(&wndclass);
-
-/*---------------------------------------------------------------------------
-    Finally, create the window.
-  ---------------------------------------------------------------------------*/
-
-    extra_width  = 2*(GetSystemMetrics(SM_CXBORDER) +
-                      GetSystemMetrics(SM_CXDLGFRAME));
-    extra_height = 2*(GetSystemMetrics(SM_CYBORDER) +
-                      GetSystemMetrics(SM_CYDLGFRAME)) +
-                      GetSystemMetrics(SM_CYCAPTION);
-
-    global_hwnd = CreateWindow(progname, titlebar, WS_OVERLAPPEDWINDOW,
-      CW_USEDEFAULT, CW_USEDEFAULT, rpng2_info.width+extra_width,
-      rpng2_info.height+extra_height, NULL, NULL, global_hInst, NULL);
-
-    ShowWindow(global_hwnd, global_showmode);
-    UpdateWindow(global_hwnd);
-
-/*---------------------------------------------------------------------------
-    Now compute the background image and display it.  If it fails (memory
-    allocation), revert to a plain background color.
-  ---------------------------------------------------------------------------*/
-
-    if (bg_image) {
-        static const char *msg = "Computing background image...";
-        int x, y, len = strlen(msg);
-        HDC hdc = GetDC(global_hwnd);
-        TEXTMETRIC tm;
-
-        GetTextMetrics(hdc, &tm);
-        x = (rpng2_info.width - len*tm.tmAveCharWidth)/2;
-        y = (rpng2_info.height - tm.tmHeight)/2;
-        SetBkMode(hdc, TRANSPARENT);
-        SetTextColor(hdc, GetSysColor(COLOR_HIGHLIGHTTEXT));
-        /* this can still begin out of bounds even if x is positive (???): */
-        TextOut(hdc, ((x < 0)? 0 : x), ((y < 0)? 0 : y), msg, len);
-        ReleaseDC(global_hwnd, hdc);
-
-        rpng2_win_load_bg_image();   /* resets bg_image if fails */
-    }
-
-    if (!bg_image) {
-        for (j = 0;  j < rpng2_info.height;  ++j) {
-            dest = wimage_data + j*wimage_rowbytes;
-            for (i = rpng2_info.width;  i > 0;  --i) {
-                *dest++ = bg_blue;
-                *dest++ = bg_green;
-                *dest++ = bg_red;
-            }
-        }
-    }
-
-    rect.left = 0L;
-    rect.top = 0L;
-    rect.right = (LONG)rpng2_info.width;       /* possibly off by one? */
-    rect.bottom = (LONG)rpng2_info.height;     /* possibly off by one? */
-    InvalidateRect(global_hwnd, &rect, FALSE);
-    UpdateWindow(global_hwnd);                 /* similar to XFlush() */
-
-    return 0;
-
-} /* end function rpng2_win_create_window() */
-
-
-
-
-
-static int rpng2_win_load_bg_image()
-{
-    uch *src, *dest;
-    uch r1, r2, g1, g2, b1, b2;
-    uch r1_inv, r2_inv, g1_inv, g2_inv, b1_inv, b2_inv;
-    int k, hmax, max;
-    int xidx, yidx, yidx_max = (bgscale-1);
-    int even_odd_vert, even_odd_horiz, even_odd;
-    int invert_gradient2 = (bg[pat].type & 0x08);
-    int invert_column;
-    ulg i, row;
-
-/*---------------------------------------------------------------------------
-    Allocate buffer for fake background image to be used with transparent
-    images; if this fails, revert to plain background color.
-  ---------------------------------------------------------------------------*/
-
-    bg_rowbytes = 3 * rpng2_info.width;
-    bg_data = (uch *)malloc(bg_rowbytes * rpng2_info.height);
-    if (!bg_data) {
-        fprintf(stderr, PROGNAME
-          ":  unable to allocate memory for background image\n");
-        bg_image = 0;
-        return 1;
-    }
-
-/*---------------------------------------------------------------------------
-    Vertical gradients (ramps) in NxN squares, alternating direction and
-    colors (N == bgscale).
-  ---------------------------------------------------------------------------*/
-
-    if ((bg[pat].type & 0x07) == 0) {
-        uch r1_min  = rgb[bg[pat].rgb1_min].r;
-        uch g1_min  = rgb[bg[pat].rgb1_min].g;
-        uch b1_min  = rgb[bg[pat].rgb1_min].b;
-        uch r2_min  = rgb[bg[pat].rgb2_min].r;
-        uch g2_min  = rgb[bg[pat].rgb2_min].g;
-        uch b2_min  = rgb[bg[pat].rgb2_min].b;
-        int r1_diff = rgb[bg[pat].rgb1_max].r - r1_min;
-        int g1_diff = rgb[bg[pat].rgb1_max].g - g1_min;
-        int b1_diff = rgb[bg[pat].rgb1_max].b - b1_min;
-        int r2_diff = rgb[bg[pat].rgb2_max].r - r2_min;
-        int g2_diff = rgb[bg[pat].rgb2_max].g - g2_min;
-        int b2_diff = rgb[bg[pat].rgb2_max].b - b2_min;
-
-        for (row = 0;  row < rpng2_info.height;  ++row) {
-            yidx = row % bgscale;
-            even_odd_vert = (row / bgscale) & 1;
-
-            r1 = r1_min + (r1_diff * yidx) / yidx_max;
-            g1 = g1_min + (g1_diff * yidx) / yidx_max;
-            b1 = b1_min + (b1_diff * yidx) / yidx_max;
-            r1_inv = r1_min + (r1_diff * (yidx_max-yidx)) / yidx_max;
-            g1_inv = g1_min + (g1_diff * (yidx_max-yidx)) / yidx_max;
-            b1_inv = b1_min + (b1_diff * (yidx_max-yidx)) / yidx_max;
-
-            r2 = r2_min + (r2_diff * yidx) / yidx_max;
-            g2 = g2_min + (g2_diff * yidx) / yidx_max;
-            b2 = b2_min + (b2_diff * yidx) / yidx_max;
-            r2_inv = r2_min + (r2_diff * (yidx_max-yidx)) / yidx_max;
-            g2_inv = g2_min + (g2_diff * (yidx_max-yidx)) / yidx_max;
-            b2_inv = b2_min + (b2_diff * (yidx_max-yidx)) / yidx_max;
-
-            dest = bg_data + row*bg_rowbytes;
-            for (i = 0;  i < rpng2_info.width;  ++i) {
-                even_odd_horiz = (i / bgscale) & 1;
-                even_odd = even_odd_vert ^ even_odd_horiz;
-                invert_column =
-                  (even_odd_horiz && (bg[pat].type & 0x10));
-                if (even_odd == 0) {         /* gradient #1 */
-                    if (invert_column) {
-                        *dest++ = r1_inv;
-                        *dest++ = g1_inv;
-                        *dest++ = b1_inv;
-                    } else {
-                        *dest++ = r1;
-                        *dest++ = g1;
-                        *dest++ = b1;
-                    }
-                } else {                     /* gradient #2 */
-                    if ((invert_column && invert_gradient2) ||
-                        (!invert_column && !invert_gradient2))
-                    {
-                        *dest++ = r2;        /* not inverted or */
-                        *dest++ = g2;        /*  doubly inverted */
-                        *dest++ = b2;
-                    } else {
-                        *dest++ = r2_inv;
-                        *dest++ = g2_inv;    /* singly inverted */
-                        *dest++ = b2_inv;
-                    }
-                }
-            }
-        }
-
-/*---------------------------------------------------------------------------
-    Soft gradient-diamonds with scale = bgscale.  Code contributed by Adam
-    M. Costello.
-  ---------------------------------------------------------------------------*/
-
-    } else if ((bg[pat].type & 0x07) == 1) {
-
-        hmax = (bgscale-1)/2;   /* half the max weight of a color */
-        max = 2*hmax;           /* the max weight of a color */
-
-        r1 = rgb[bg[pat].rgb1_max].r;
-        g1 = rgb[bg[pat].rgb1_max].g;
-        b1 = rgb[bg[pat].rgb1_max].b;
-        r2 = rgb[bg[pat].rgb2_max].r;
-        g2 = rgb[bg[pat].rgb2_max].g;
-        b2 = rgb[bg[pat].rgb2_max].b;
-
-        for (row = 0;  row < rpng2_info.height;  ++row) {
-            yidx = row % bgscale;
-            if (yidx > hmax)
-                yidx = bgscale-1 - yidx;
-            dest = bg_data + row*bg_rowbytes;
-            for (i = 0;  i < rpng2_info.width;  ++i) {
-                xidx = i % bgscale;
-                if (xidx > hmax)
-                    xidx = bgscale-1 - xidx;
-                k = xidx + yidx;
-                *dest++ = (k*r1 + (max-k)*r2) / max;
-                *dest++ = (k*g1 + (max-k)*g2) / max;
-                *dest++ = (k*b1 + (max-k)*b2) / max;
-            }
-        }
-
-/*---------------------------------------------------------------------------
-    Radial "starburst" with azimuthal sinusoids; [eventually number of sinu-
-    soids will equal bgscale?].  This one is slow but very cool.  Code con-
-    tributed by Pieter S. van der Meulen (originally in Smalltalk).
-  ---------------------------------------------------------------------------*/
-
-    } else if ((bg[pat].type & 0x07) == 2) {
-        uch ch;
-        int ii, x, y, hw, hh, grayspot;
-        double freq, rotate, saturate, gray, intensity;
-        double angle=0.0, aoffset=0.0, maxDist, dist;
-        double red=0.0, green=0.0, blue=0.0, hue, s, v, f, p, q, t;
-
-        fprintf(stderr, "%s:  computing radial background...",
-          PROGNAME);
-        fflush(stderr);
-
-        hh = rpng2_info.height / 2;
-        hw = rpng2_info.width / 2;
-
-        /* variables for radial waves:
-         *   aoffset:  number of degrees to rotate hue [CURRENTLY NOT USED]
-         *   freq:  number of color beams originating from the center
-         *   grayspot:  size of the graying center area (anti-alias)
-         *   rotate:  rotation of the beams as a function of radius
-         *   saturate:  saturation of beams' shape azimuthally
-         */
-        angle = CLIP(angle, 0.0, 360.0);
-        grayspot = CLIP(bg[pat].bg_gray, 1, (hh + hw));
-        freq = MAX((double)bg[pat].bg_freq, 0.0);
-        saturate = (double)bg[pat].bg_bsat * 0.1;
-        rotate = (double)bg[pat].bg_brot * 0.1;
-        gray = 0.0;
-        intensity = 0.0;
-        maxDist = (double)((hw*hw) + (hh*hh));
-
-        for (row = 0;  row < rpng2_info.height;  ++row) {
-            y = row - hh;
-            dest = bg_data + row*bg_rowbytes;
-            for (i = 0;  i < rpng2_info.width;  ++i) {
-                x = i - hw;
-                angle = (x == 0)? PI_2 : atan((double)y / (double)x);
-                gray = (double)MAX(ABS(y), ABS(x)) / grayspot;
-                gray = MIN(1.0, gray);
-                dist = (double)((x*x) + (y*y)) / maxDist;
-                intensity = cos((angle+(rotate*dist*PI)) * freq) *
-                  gray * saturate;
-                intensity = (MAX(MIN(intensity,1.0),-1.0) + 1.0) * 0.5;
-                hue = (angle + PI) * INV_PI_360 + aoffset;
-                s = gray * ((double)(ABS(x)+ABS(y)) / (double)(hw + hh));
-                s = MIN(MAX(s,0.0), 1.0);
-                v = MIN(MAX(intensity,0.0), 1.0);
-
-                if (s == 0.0) {
-                    ch = (uch)(v * 255.0);
-                    *dest++ = ch;
-                    *dest++ = ch;
-                    *dest++ = ch;
-                } else {
-                    if ((hue < 0.0) || (hue >= 360.0))
-                        hue -= (((int)(hue / 360.0)) * 360.0);
-                    hue /= 60.0;
-                    ii = (int)hue;
-                    f = hue - (double)ii;
-                    p = (1.0 - s) * v;
-                    q = (1.0 - (s * f)) * v;
-                    t = (1.0 - (s * (1.0 - f))) * v;
-                    if      (ii == 0) { red = v; green = t; blue = p; }
-                    else if (ii == 1) { red = q; green = v; blue = p; }
-                    else if (ii == 2) { red = p; green = v; blue = t; }
-                    else if (ii == 3) { red = p; green = q; blue = v; }
-                    else if (ii == 4) { red = t; green = p; blue = v; }
-                    else if (ii == 5) { red = v; green = p; blue = q; }
-                    *dest++ = (uch)(red * 255.0);
-                    *dest++ = (uch)(green * 255.0);
-                    *dest++ = (uch)(blue * 255.0);
-                }
-            }
-        }
-        fprintf(stderr, "done.\n");
-        fflush(stderr);
-    }
-
-/*---------------------------------------------------------------------------
-    Blast background image to display buffer before beginning PNG decode;
-    calling function will handle invalidation and UpdateWindow() call.
-  ---------------------------------------------------------------------------*/
-
-    for (row = 0;  row < rpng2_info.height;  ++row) {
-        src = bg_data + row*bg_rowbytes;
-        dest = wimage_data + row*wimage_rowbytes;
-        for (i = rpng2_info.width;  i > 0;  --i) {
-            r1 = *src++;
-            g1 = *src++;
-            b1 = *src++;
-            *dest++ = b1;
-            *dest++ = g1;   /* note reverse order */
-            *dest++ = r1;
-        }
-    }
-
-    return 0;
-
-} /* end function rpng2_win_load_bg_image() */
-
-
-
-
-
-static void rpng2_win_display_row(ulg row)
-{
-    uch bg_red   = rpng2_info.bg_red;
-    uch bg_green = rpng2_info.bg_green;
-    uch bg_blue  = rpng2_info.bg_blue;
-    uch *src, *src2=NULL, *dest;
-    uch r, g, b, a;
-    ulg i;
-    static int rows=0;
-    static ulg firstrow;
-
-/*---------------------------------------------------------------------------
-    rows and firstrow simply track how many rows (and which ones) have not
-    yet been displayed; alternatively, we could call InvalidateRect() for
-    every row and not bother with the records-keeping.
-  ---------------------------------------------------------------------------*/
-
-    Trace((stderr, "beginning rpng2_win_display_row()\n"))
-
-    if (rows == 0)
-        firstrow = row;   /* first row not yet displayed */
-
-    ++rows;   /* count of rows received but not yet displayed */
-
-/*---------------------------------------------------------------------------
-    Aside from the use of the rpng2_info struct and the lack of an outer
-    loop (over rows), this routine is identical to rpng_win_display_image()
-    in the non-progressive version of the program.
-  ---------------------------------------------------------------------------*/
-
-    src = rpng2_info.image_data + row*rpng2_info.rowbytes;
-    if (bg_image)
-        src2 = bg_data + row*bg_rowbytes;
-    dest = wimage_data + row*wimage_rowbytes;
-
-    if (rpng2_info.channels == 3) {
-        for (i = rpng2_info.width;  i > 0;  --i) {
-            r = *src++;
-            g = *src++;
-            b = *src++;
-            *dest++ = b;
-            *dest++ = g;   /* note reverse order */
-            *dest++ = r;
-        }
-    } else /* if (rpng2_info.channels == 4) */ {
-        for (i = rpng2_info.width;  i > 0;  --i) {
-            r = *src++;
-            g = *src++;
-            b = *src++;
-            a = *src++;
-            if (bg_image) {
-                bg_red   = *src2++;
-                bg_green = *src2++;
-                bg_blue  = *src2++;
-            }
-            if (a == 255) {
-                *dest++ = b;
-                *dest++ = g;
-                *dest++ = r;
-            } else if (a == 0) {
-                *dest++ = bg_blue;
-                *dest++ = bg_green;
-                *dest++ = bg_red;
-            } else {
-                /* this macro (copied from png.h) composites the
-                 * foreground and background values and puts the
-                 * result into the first argument; there are no
-                 * side effects with the first argument */
-                alpha_composite(*dest++, b, a, bg_blue);
-                alpha_composite(*dest++, g, a, bg_green);
-                alpha_composite(*dest++, r, a, bg_red);
-            }
-        }
-    }
-
-/*---------------------------------------------------------------------------
-    Display after every 16 rows or when on last row.  (Region may include
-    previously displayed lines due to interlacing--i.e., not contiguous.)
-  ---------------------------------------------------------------------------*/
-
-    if ((rows & 0xf) == 0 || row == rpng2_info.height-1) {
-        RECT rect;
-
-        rect.left = 0L;
-        rect.top = (LONG)firstrow;
-        rect.right = (LONG)rpng2_info.width;       /* possibly off by one? */
-        rect.bottom = (LONG)row + 1L;              /* possibly off by one? */
-        InvalidateRect(global_hwnd, &rect, FALSE);
-        UpdateWindow(global_hwnd);                 /* similar to XFlush() */
-        rows = 0;
-    }
-
-} /* end function rpng2_win_display_row() */
-
-
-
-
-
-static void rpng2_win_finish_display()
-{
-    Trace((stderr, "beginning rpng2_win_finish_display()\n"))
-
-    /* last row has already been displayed by rpng2_win_display_row(), so
-     * we have nothing to do here except set a flag and let the user know
-     * that the image is done */
-
-    rpng2_info.state = kDone;
-    printf(
-      "Done.  Press Q, Esc or mouse button 1 (within image window) to quit.\n");
-    fflush(stdout);
-}
-
-
-
-
-
-static void rpng2_win_cleanup()
-{
-    if (bg_image && bg_data) {
-        free(bg_data);
-        bg_data = NULL;
-    }
-
-    if (rpng2_info.image_data) {
-        free(rpng2_info.image_data);
-        rpng2_info.image_data = NULL;
-    }
-
-    if (rpng2_info.row_pointers) {
-        free(rpng2_info.row_pointers);
-        rpng2_info.row_pointers = NULL;
-    }
-
-    if (dib) {
-        free(dib);
-        dib = NULL;
-    }
-}
-
-
-
-
-
-LRESULT CALLBACK rpng2_win_wndproc(HWND hwnd, UINT iMsg, WPARAM wP, LPARAM lP)
-{
-    HDC         hdc;
-    PAINTSTRUCT ps;
-    int rc;
-
-    switch (iMsg) {
-        case WM_CREATE:
-            /* one-time processing here, if any */
-            return 0;
-
-        case WM_PAINT:
-            hdc = BeginPaint(hwnd, &ps);
-            rc = StretchDIBits(hdc, 0, 0, rpng2_info.width, rpng2_info.height,
-                                    0, 0, rpng2_info.width, rpng2_info.height,
-                                    wimage_data, (BITMAPINFO *)bmih,
-                                    0, SRCCOPY);
-            EndPaint(hwnd, &ps);
-            return 0;
-
-        /* wait for the user to tell us when to quit */
-        case WM_CHAR:
-            switch (wP) {       /* only need one, so ignore repeat count */
-                case 'q':
-                case 'Q':
-                case 0x1B:      /* Esc key */
-                    PostQuitMessage(0);
-            }
-            return 0;
-
-        case WM_LBUTTONDOWN:    /* another way of quitting */
-        case WM_DESTROY:
-            PostQuitMessage(0);
-            return 0;
-    }
-
-    return DefWindowProc(hwnd, iMsg, wP, lP);
-}
diff --git a/contrib/gregbook/rpng2-x.c b/contrib/gregbook/rpng2-x.c
deleted file mode 100644
index 873af23..0000000
--- a/contrib/gregbook/rpng2-x.c
+++ /dev/null
@@ -1,2127 +0,0 @@
-/*---------------------------------------------------------------------------
-
-   rpng2 - progressive-model PNG display program                  rpng2-x.c
-
-   This program decodes and displays PNG files progressively, as if it were
-   a web browser (though the front end is only set up to read from files).
-   It supports gamma correction, user-specified background colors, and user-
-   specified background patterns (for transparent images).  This version is
-   for the X Window System (tested by the author under Unix and by Martin
-   Zinser under OpenVMS; may work under OS/2 with a little tweaking).
-
-   Thanks to Adam Costello and Pieter S. van der Meulen for the "diamond"
-   and "radial waves" patterns, respectively.
-
-   to do (someday, maybe):
-    - fix expose/redraw code:  don't draw entire row if only part exposed
-    - 8-bit (colormapped) X support
-    - finish resizable checkerboard-gradient (sizes 4-128?)
-    - use %.1023s to simplify truncation of title-bar string?
-
-  ---------------------------------------------------------------------------
-
-   Changelog:
-    - 1.01:  initial public release
-    - 1.02:  modified to allow abbreviated options; fixed char/uchar mismatch
-    - 1.10:  added support for non-default visuals; fixed X pixel-conversion
-    - 1.11:  added -usleep option for demos; fixed command-line parsing bug
-    - 1.12:  added -pause option for demos and testing
-    - 1.20:  added runtime MMX-enabling/disabling and new -mmx* options
-    - 1.21:  fixed some small X memory leaks (thanks to François Petitjean)
-    - 1.22:  fixed XFreeGC() crash bug (thanks to Patrick Welche)
-    - 1.23:  added -bgpat 0 mode (std white/gray checkerboard, 8x8 squares)
-    - 1.30:  added -loop option for -bgpat (ifdef FEATURE_LOOP); fixed bpp =
-              24; added support for X resources (thanks to Gerhard Niklasch)
-    - 1.31:  added code to skip unused chunks (thanks to Glenn Randers-Pehrson)
-    - 1.32:  added AMD64/EM64T support (__x86_64__); added basic expose/redraw
-              handling
-    - 2.00:  dual-licensed (added GNU GPL)
-    - 2.01:  fixed 64-bit typo in readpng2.c; fixed -pause usage description
-    - 2.02:  fixed improper display of usage screen on PNG error(s); fixed
-              unexpected-EOF and file-read-error cases; fixed Trace() cut-and-
-              paste bugs
-
-  ---------------------------------------------------------------------------
-
-      Copyright (c) 1998-2008 Greg Roelofs.  All rights reserved.
-
-      This software is provided "as is," without warranty of any kind,
-      express or implied.  In no event shall the author or contributors
-      be held liable for any damages arising in any way from the use of
-      this software.
-
-      The contents of this file are DUAL-LICENSED.  You may modify and/or
-      redistribute this software according to the terms of one of the
-      following two licenses (at your option):
-
-
-      LICENSE 1 ("BSD-like with advertising clause"):
-
-      Permission is granted to anyone to use this software for any purpose,
-      including commercial applications, and to alter it and redistribute
-      it freely, subject to the following restrictions:
-
-      1. Redistributions of source code must retain the above copyright
-         notice, disclaimer, and this list of conditions.
-      2. Redistributions in binary form must reproduce the above copyright
-         notice, disclaimer, and this list of conditions in the documenta-
-         tion and/or other materials provided with the distribution.
-      3. All advertising materials mentioning features or use of this
-         software must display the following acknowledgment:
-
-            This product includes software developed by Greg Roelofs
-            and contributors for the book, "PNG: The Definitive Guide,"
-            published by O'Reilly and Associates.
-
-
-      LICENSE 2 (GNU GPL v2 or later):
-
-      This program is free software; you can redistribute it and/or modify
-      it under the terms of the GNU General Public License as published by
-      the Free Software Foundation; either version 2 of the License, or
-      (at your option) any later version.
-
-      This program is distributed in the hope that it will be useful,
-      but WITHOUT ANY WARRANTY; without even the implied warranty of
-      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-      GNU General Public License for more details.
-
-      You should have received a copy of the GNU General Public License
-      along with this program; if not, write to the Free Software Foundation,
-      Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
-
-  ---------------------------------------------------------------------------*/
-
-#define PROGNAME  "rpng2-x"
-#define LONGNAME  "Progressive PNG Viewer for X"
-#define VERSION   "2.02 of 16 March 2008"
-#define RESNAME   "rpng2"	/* our X resource application name */
-#define RESCLASS  "Rpng"	/* our X resource class name */
-
-#include <stdio.h>
-#include <stdlib.h>
-#include <ctype.h>
-#include <string.h>
-#include <setjmp.h>       /* for jmpbuf declaration in readpng2.h */
-#include <time.h>
-#include <math.h>         /* only for PvdM background code */
-#include <X11/Xlib.h>
-#include <X11/Xutil.h>
-#include <X11/Xos.h>
-#include <X11/keysym.h>   /* defines XK_* macros */
-
-#ifdef VMS
-#  include <unistd.h>
-#endif
-
-/* all for PvdM background code: */
-#ifndef PI
-#  define PI             3.141592653589793238
-#endif
-#define PI_2             (PI*0.5)
-#define INV_PI_360       (360.0 / PI)
-#define MAX(a,b)         (a>b?a:b)
-#define MIN(a,b)         (a<b?a:b)
-#define CLIP(a,min,max)  MAX(min,MIN((a),max))
-#define ABS(a)           ((a)<0?-(a):(a))
-#define CLIP8P(c)        MAX(0,(MIN((c),255)))   /* 8-bit pos. integer (uch) */
-#define ROUNDF(f)        ((int)(f + 0.5))
-
-#define QUIT(e,k) ((e.type == ButtonPress && e.xbutton.button == Button1) ||  \
-                  (e.type == KeyPress &&   /*  v--- or 1 for shifted keys */  \
-                  ((k = XLookupKeysym(&e.xkey, 0)) == XK_q || k == XK_Escape)))
-
-#define NO_24BIT_MASKS	/* undef case not fully written--only for redisplay() */
-
-#define rgb1_max   bg_freq
-#define rgb1_min   bg_gray
-#define rgb2_max   bg_bsat
-#define rgb2_min   bg_brot
-
-/* #define DEBUG */     /* this enables the Trace() macros */
-
-#include "readpng2.h"   /* typedefs, common macros, readpng2 prototypes */
-
-
-/* could just include png.h, but this macro is the only thing we need
- * (name and typedefs changed to local versions); note that side effects
- * only happen with alpha (which could easily be avoided with
- * "ush acopy = (alpha);") */
-
-#define alpha_composite(composite, fg, alpha, bg) {               \
-    ush temp = ((ush)(fg)*(ush)(alpha) +                          \
-                (ush)(bg)*(ush)(255 - (ush)(alpha)) + (ush)128);  \
-    (composite) = (uch)((temp + (temp >> 8)) >> 8);               \
-}
-
-
-#define INBUFSIZE 4096   /* with pseudo-timing on (1 sec delay/block), this
-                          *  block size corresponds roughly to a download
-                          *  speed 10% faster than theoretical 33.6K maximum
-                          *  (assuming 8 data bits, 1 stop bit and no other
-                          *  overhead) */
-
-/* local prototypes */
-static void rpng2_x_init (void);
-static int  rpng2_x_create_window (void);
-static int  rpng2_x_load_bg_image (void);
-static void rpng2_x_display_row (ulg row);
-static void rpng2_x_finish_display (void);
-static void rpng2_x_redisplay_image (ulg startcol, ulg startrow,
-                                     ulg width, ulg height);
-#ifdef FEATURE_LOOP
-static void rpng2_x_reload_bg_image (void);
-static int  is_number (char *p);
-#endif
-static void rpng2_x_cleanup (void);
-static int  rpng2_x_msb (ulg u32val);
-
-
-static char titlebar[1024], *window_name = titlebar;
-static char *appname = LONGNAME;
-static char *icon_name = PROGNAME;
-static char *res_name = RESNAME;
-static char *res_class = RESCLASS;
-static char *filename;
-static FILE *infile;
-
-static mainprog_info rpng2_info;
-
-static uch inbuf[INBUFSIZE];
-static int incount;
-
-static int pat = 6;        /* must be less than num_bgpat */
-static int bg_image = 0;
-static int bgscale, bgscale_default = 16;
-static ulg bg_rowbytes;
-static uch *bg_data;
-
-int pause_after_pass = FALSE;
-int demo_timing = FALSE;
-ulg usleep_duration = 0L;
-
-static struct rgb_color {
-    uch r, g, b;
-} rgb[] = {
-    {  0,   0,   0},    /*  0:  black */
-    {255, 255, 255},    /*  1:  white */
-    {173, 132,  57},    /*  2:  tan */
-    { 64, 132,   0},    /*  3:  medium green */
-    {189, 117,   1},    /*  4:  gold */
-    {253, 249,   1},    /*  5:  yellow */
-    {  0,   0, 255},    /*  6:  blue */
-    {  0,   0, 120},    /*  7:  medium blue */
-    {255,   0, 255},    /*  8:  magenta */
-    { 64,   0,  64},    /*  9:  dark magenta */
-    {255,   0,   0},    /* 10:  red */
-    { 64,   0,   0},    /* 11:  dark red */
-    {255, 127,   0},    /* 12:  orange */
-    {192,  96,   0},    /* 13:  darker orange */
-    { 24,  60,   0},    /* 14:  dark green-yellow */
-    { 85, 125, 200},    /* 15:  ice blue */
-    {192, 192, 192}     /* 16:  Netscape/Mosaic gray */
-};
-/* not used for now, but should be for error-checking:
-static int num_rgb = sizeof(rgb) / sizeof(struct rgb_color);
- */
-
-/*
-    This whole struct is a fairly cheesy way to keep the number of
-    command-line options to a minimum.  The radial-waves background
-    type is a particularly poor fit to the integer elements of the
-    struct...but a few macros and a little fixed-point math will do
-    wonders for ya.
-
-    type bits:
-       F E D C B A 9 8 7 6 5 4 3 2 1 0
-                             | | | | |
-                             | | +-+-+-- 0 = sharp-edged checkerboard
-                             | |         1 = soft diamonds
-                             | |         2 = radial waves
-                             | |       3-7 = undefined
-                             | +-- gradient #2 inverted?
-                             +-- alternating columns inverted?
- */
-static struct background_pattern {
-    ush type;
-    int rgb1_max, rgb1_min;     /* or bg_freq, bg_gray */
-    int rgb2_max, rgb2_min;     /* or bg_bsat, bg_brot (both scaled by 10)*/
-} bg[] = {
-    {0,     1,1, 16,16},        /* checkered:  white vs. light gray (basic) */
-    {0+8,   2,0,  1,15},        /* checkered:  tan/black vs. white/ice blue */
-    {0+24,  2,0,  1,0},         /* checkered:  tan/black vs. white/black */
-    {0+8,   4,5,  0,2},         /* checkered:  gold/yellow vs. black/tan */
-    {0+8,   4,5,  0,6},         /* checkered:  gold/yellow vs. black/blue */
-    {0,     7,0,  8,9},         /* checkered:  deep blue/black vs. magenta */
-    {0+8,  13,0,  5,14},        /* checkered:  orange/black vs. yellow */
-    {0+8,  12,0, 10,11},        /* checkered:  orange/black vs. red */
-    {1,     7,0,  8,0},         /* diamonds:  deep blue/black vs. magenta */
-    {1,    12,0, 11,0},         /* diamonds:  orange vs. dark red */
-    {1,    10,0,  7,0},         /* diamonds:  red vs. medium blue */
-    {1,     4,0,  5,0},         /* diamonds:  gold vs. yellow */
-    {1,     3,0,  0,0},         /* diamonds:  medium green vs. black */
-    {2,    16, 100,  20,   0},  /* radial:  ~hard radial color-beams */
-    {2,    18, 100,  10,   2},  /* radial:  soft, curved radial color-beams */
-    {2,    16, 256, 100, 250},  /* radial:  very tight spiral */
-    {2, 10000, 256,  11,   0}   /* radial:  dipole-moire' (almost fractal) */
-};
-static int num_bgpat = sizeof(bg) / sizeof(struct background_pattern);
-
-
-/* X-specific variables */
-static char *displayname;
-static XImage *ximage;
-static Display *display;
-static int depth;
-static Visual *visual;
-static XVisualInfo *visual_list;
-static int RShift, GShift, BShift;
-static ulg RMask, GMask, BMask;
-static Window window;
-static GC gc;
-static Colormap colormap;
-
-static int have_nondefault_visual = FALSE;
-static int have_colormap = FALSE;
-static int have_window = FALSE;
-static int have_gc = FALSE;
-
-
-
-
-int main(int argc, char **argv)
-{
-#ifdef sgi
-    char tmpline[80];
-#endif
-    char *p, *bgstr = NULL;
-    int rc, alen, flen;
-    int error = 0;
-    int timing = FALSE;
-    int have_bg = FALSE;
-#ifdef FEATURE_LOOP
-    int loop = FALSE;
-    long loop_interval = -1;		/* seconds (100,000 max) */
-#endif
-    double LUT_exponent;                /* just the lookup table */
-    double CRT_exponent = 2.2;          /* just the monitor */
-    double default_display_exponent;    /* whole display system */
-    XEvent e;
-    KeySym k;
-
-
-    /* First initialize a few things, just to be sure--memset takes care of
-     * default background color (black), booleans (FALSE), pointers (NULL),
-     * etc. */
-
-    displayname = (char *)NULL;
-    filename = (char *)NULL;
-    memset(&rpng2_info, 0, sizeof(mainprog_info));
-
-
-    /* Set the default value for our display-system exponent, i.e., the
-     * product of the CRT exponent and the exponent corresponding to
-     * the frame-buffer's lookup table (LUT), if any.  This is not an
-     * exhaustive list of LUT values (e.g., OpenStep has a lot of weird
-     * ones), but it should cover 99% of the current possibilities. */
-
-#if defined(NeXT)
-    /* third-party utilities can modify the default LUT exponent */
-    LUT_exponent = 1.0 / 2.2;
-    /*
-    if (some_next_function_that_returns_gamma(&next_gamma))
-        LUT_exponent = 1.0 / next_gamma;
-     */
-#elif defined(sgi)
-    LUT_exponent = 1.0 / 1.7;
-    /* there doesn't seem to be any documented function to
-     * get the "gamma" value, so we do it the hard way */
-    infile = fopen("/etc/config/system.glGammaVal", "r");
-    if (infile) {
-        double sgi_gamma;
-
-        fgets(tmpline, 80, infile);
-        fclose(infile);
-        sgi_gamma = atof(tmpline);
-        if (sgi_gamma > 0.0)
-            LUT_exponent = 1.0 / sgi_gamma;
-    }
-#elif defined(Macintosh)
-    LUT_exponent = 1.8 / 2.61;
-    /*
-    if (some_mac_function_that_returns_gamma(&mac_gamma))
-        LUT_exponent = mac_gamma / 2.61;
-     */
-#else
-    LUT_exponent = 1.0;   /* assume no LUT:  most PCs */
-#endif
-
-    /* the defaults above give 1.0, 1.3, 1.5 and 2.2, respectively: */
-    default_display_exponent = LUT_exponent * CRT_exponent;
-
-
-    /* If the user has set the SCREEN_GAMMA environment variable as suggested
-     * (somewhat imprecisely) in the libpng documentation, use that; otherwise
-     * use the default value we just calculated.  Either way, the user may
-     * override this via a command-line option. */
-
-    if ((p = getenv("SCREEN_GAMMA")) != NULL)
-        rpng2_info.display_exponent = atof(p);
-    else
-        rpng2_info.display_exponent = default_display_exponent;
-
-
-    /* Now parse the command line for options and the PNG filename. */
-
-    while (*++argv && !error) {
-        if (!strncmp(*argv, "-display", 2)) {
-            if (!*++argv)
-                ++error;
-            else
-                displayname = *argv;
-        } else if (!strncmp(*argv, "-gamma", 2)) {
-            if (!*++argv)
-                ++error;
-            else {
-                rpng2_info.display_exponent = atof(*argv);
-                if (rpng2_info.display_exponent <= 0.0)
-                    ++error;
-            }
-        } else if (!strncmp(*argv, "-bgcolor", 4)) {
-            if (!*++argv)
-                ++error;
-            else {
-                bgstr = *argv;
-                if (strlen(bgstr) != 7 || bgstr[0] != '#')
-                    ++error;
-                else {
-                    have_bg = TRUE;
-                    bg_image = FALSE;
-                }
-            }
-        } else if (!strncmp(*argv, "-bgpat", 4)) {
-            if (!*++argv)
-                ++error;
-            else {
-                pat = atoi(*argv);
-                if (pat >= 0 && pat < num_bgpat) {
-                    bg_image = TRUE;
-                    have_bg = FALSE;
-                } else
-                    ++error;
-            }
-        } else if (!strncmp(*argv, "-usleep", 2)) {
-            if (!*++argv)
-                ++error;
-            else {
-                usleep_duration = (ulg)atol(*argv);
-                demo_timing = TRUE;
-            }
-        } else if (!strncmp(*argv, "-pause", 2)) {
-            pause_after_pass = TRUE;
-        } else if (!strncmp(*argv, "-timing", 2)) {
-            timing = TRUE;
-#ifdef FEATURE_LOOP
-        } else if (!strncmp(*argv, "-loop", 2)) {
-            loop = TRUE;
-            if (!argv[1] || !is_number(argv[1]))
-                loop_interval = 2;
-            else {
-                ++argv;
-                loop_interval = atol(*argv);
-                if (loop_interval < 0)
-                    loop_interval = 2;
-                else if (loop_interval > 100000)   /* bit more than one day */
-                    loop_interval = 100000;
-            }
-#endif
-#if (defined(__i386__) || defined(_M_IX86) || defined(__x86_64__))
-        } else if (!strncmp(*argv, "-nommxfilters", 7)) {
-            rpng2_info.nommxfilters = TRUE;
-        } else if (!strncmp(*argv, "-nommxcombine", 7)) {
-            rpng2_info.nommxcombine = TRUE;
-        } else if (!strncmp(*argv, "-nommxinterlace", 7)) {
-            rpng2_info.nommxinterlace = TRUE;
-        } else if (!strcmp(*argv, "-nommx")) {
-            rpng2_info.nommxfilters = TRUE;
-            rpng2_info.nommxcombine = TRUE;
-            rpng2_info.nommxinterlace = TRUE;
-#endif
-        } else {
-            if (**argv != '-') {
-                filename = *argv;
-                if (argv[1])   /* shouldn't be any more args after filename */
-                    ++error;
-            } else
-                ++error;   /* not expecting any other options */
-        }
-    }
-
-    if (!filename)
-        ++error;
-
-
-    /* print usage screen if any errors up to this point */
-
-    if (error) {
-        fprintf(stderr, "\n%s %s:  %s\n\n", PROGNAME, VERSION, appname);
-        readpng2_version_info();
-        fprintf(stderr, "\n"
-          "Usage:  %s [-display xdpy] [-gamma exp] [-bgcolor bg | -bgpat pat]\n"
-#if (defined(__i386__) || defined(_M_IX86) || defined(__x86_64__))
-          "        %*s [[-nommxfilters] [-nommxcombine] [-nommxinterlace] | -nommx]\n"
-#endif
-#ifdef FEATURE_LOOP
-          "        %*s [-usleep dur | -timing] [-pause] [-loop [sec]] file.png\n\n"
-#else
-          "        %*s [-usleep dur | -timing] [-pause] file.png\n\n"
-#endif
-          "    xdpy\tname of the target X display (e.g., ``hostname:0'')\n"
-          "    exp \ttransfer-function exponent (``gamma'') of the display\n"
-          "\t\t  system in floating-point format (e.g., ``%.1f''); equal\n"
-          "\t\t  to the product of the lookup-table exponent (varies)\n"
-          "\t\t  and the CRT exponent (usually 2.2); must be positive\n"
-          "    bg  \tdesired background color in 7-character hex RGB format\n"
-          "\t\t  (e.g., ``#ff7700'' for orange:  same as HTML colors);\n"
-          "\t\t  used with transparent images; overrides -bgpat\n"
-          "    pat \tdesired background pattern number (0-%d); used with\n"
-          "\t\t  transparent images; overrides -bgcolor\n"
-#ifdef FEATURE_LOOP
-          "    -loop\tloops through background images after initial display\n"
-          "\t\t  is complete (depends on -bgpat)\n"
-          "    sec \tseconds to display each background image (default = 2)\n"
-#endif
-#if (defined(__i386__) || defined(_M_IX86) || defined(__x86_64__))
-          "    -nommx*\tdisable optimized MMX routines for decoding row filters,\n"
-          "\t\t  combining rows, and expanding interlacing, respectively\n"
-#endif
-          "    dur \tduration in microseconds to wait after displaying each\n"
-          "\t\t  row (for demo purposes)\n"
-          "    -timing\tenables delay for every block read, to simulate modem\n"
-          "\t\t  download of image (~36 Kbps)\n"
-          "    -pause\tpauses after displaying each pass until mouse clicked\n"
-          "\nPress Q, Esc or mouse button 1 (within image window, after image\n"
-          "is displayed) to quit.\n"
-          "\n", PROGNAME,
-#if (defined(__i386__) || defined(_M_IX86) || defined(__x86_64__))
-          (int)strlen(PROGNAME), " ",
-#endif
-          (int)strlen(PROGNAME), " ", default_display_exponent, num_bgpat-1);
-        exit(1);
-    }
-
-
-    if (!(infile = fopen(filename, "rb"))) {
-        fprintf(stderr, PROGNAME ":  can't open PNG file [%s]\n", filename);
-        ++error;
-    } else {
-        incount = fread(inbuf, 1, INBUFSIZE, infile);
-        if (incount < 8 || !readpng2_check_sig(inbuf, 8)) {
-            fprintf(stderr, PROGNAME
-              ":  [%s] is not a PNG file: incorrect signature\n",
-              filename);
-            ++error;
-        } else if ((rc = readpng2_init(&rpng2_info)) != 0) {
-            switch (rc) {
-                case 2:
-                    fprintf(stderr, PROGNAME
-                      ":  [%s] has bad IHDR (libpng longjmp)\n", filename);
-                    break;
-                case 4:
-                    fprintf(stderr, PROGNAME ":  insufficient memory\n");
-                    break;
-                default:
-                    fprintf(stderr, PROGNAME
-                      ":  unknown readpng2_init() error\n");
-                    break;
-            }
-            ++error;
-        } else {
-            Trace((stderr, "about to call XOpenDisplay()\n"))
-            display = XOpenDisplay(displayname);
-            if (!display) {
-                readpng2_cleanup(&rpng2_info);
-                fprintf(stderr, PROGNAME ":  can't open X display [%s]\n",
-                  displayname? displayname : "default");
-                ++error;
-            }
-        }
-        if (error)
-            fclose(infile);
-    }
-
-
-    if (error) {
-        fprintf(stderr, PROGNAME ":  aborting.\n");
-        exit(2);
-    }
-
-
-    /* set the title-bar string, but make sure buffer doesn't overflow */
-
-    alen = strlen(appname);
-    flen = strlen(filename);
-    if (alen + flen + 3 > 1023)
-        sprintf(titlebar, "%s:  ...%s", appname, filename+(alen+flen+6-1023));
-    else
-        sprintf(titlebar, "%s:  %s", appname, filename);
-
-
-    /* set some final rpng2_info variables before entering main data loop */
-
-    if (have_bg) {
-        unsigned r, g, b;   /* this approach quiets compiler warnings */
-
-        sscanf(bgstr+1, "%2x%2x%2x", &r, &g, &b);
-        rpng2_info.bg_red   = (uch)r;
-        rpng2_info.bg_green = (uch)g;
-        rpng2_info.bg_blue  = (uch)b;
-    } else
-        rpng2_info.need_bgcolor = TRUE;
-
-    rpng2_info.state = kPreInit;
-    rpng2_info.mainprog_init = rpng2_x_init;
-    rpng2_info.mainprog_display_row = rpng2_x_display_row;
-    rpng2_info.mainprog_finish_display = rpng2_x_finish_display;
-
-
-    /* OK, this is the fun part:  call readpng2_decode_data() at the start of
-     * the loop to deal with our first buffer of data (read in above to verify
-     * that the file is a PNG image), then loop through the file and continue
-     * calling the same routine to handle each chunk of data.  It in turn
-     * passes the data to libpng, which will invoke one or more of our call-
-     * backs as decoded data become available.  We optionally call sleep() for
-     * one second per iteration to simulate downloading the image via an analog
-     * modem. */
-
-    for (;;) {
-        Trace((stderr, "about to call readpng2_decode_data()\n"))
-        if (readpng2_decode_data(&rpng2_info, inbuf, incount))
-            ++error;
-        Trace((stderr, "done with readpng2_decode_data()\n"))
-
-        if (error || incount != INBUFSIZE || rpng2_info.state == kDone) {
-            if (rpng2_info.state == kDone) {
-                Trace((stderr, "done decoding PNG image\n"))
-            } else if (ferror(infile)) {
-                fprintf(stderr, PROGNAME
-                  ":  error while reading PNG image file\n");
-                exit(3);
-            } else if (feof(infile)) {
-                fprintf(stderr, PROGNAME ":  end of file reached "
-                  "(unexpectedly) while reading PNG image file\n");
-                exit(3);
-            } else /* if (error) */ {
-                // will print error message below
-            }
-            break;
-        }
-
-        if (timing)
-            sleep(1);
-
-        incount = fread(inbuf, 1, INBUFSIZE, infile);
-    }
-
-
-    /* clean up PNG stuff and report any decoding errors */
-
-    fclose(infile);
-    Trace((stderr, "about to call readpng2_cleanup()\n"))
-    readpng2_cleanup(&rpng2_info);
-
-    if (error) {
-        fprintf(stderr, PROGNAME ":  libpng error while decoding PNG image\n");
-        exit(3);
-    }
-
-
-#ifdef FEATURE_LOOP
-
-    if (loop && bg_image) {
-        Trace((stderr, "entering -loop loop (FEATURE_LOOP)\n"))
-        for (;;) {
-            int i, use_sleep;
-            struct timeval now, then;
-
-            /* get current time and add loop_interval to get target time */
-            if (gettimeofday(&then, NULL) == 0) {
-                then.tv_sec += loop_interval;
-                use_sleep = FALSE;
-            } else
-                use_sleep = TRUE;
-
-            /* do quick check for a quit event but don't wait for it */
-            /* GRR BUG:  should also check for Expose events and redraw... */
-            if (XCheckMaskEvent(display, KeyPressMask | ButtonPressMask, &e))
-                if (QUIT(e,k))
-                    break;
-
-            /* generate next background image */
-            if (++pat >= num_bgpat)
-                pat = 0;
-            rpng2_x_reload_bg_image();
-
-            /* wait for timeout, using whatever means are available */
-            if (use_sleep || gettimeofday(&now, NULL) != 0) {
-                for (i = loop_interval;  i > 0;  --i) {
-                    sleep(1);
-                    /* GRR BUG:  also need to check for Expose (and redraw!) */
-                    if (XCheckMaskEvent(display, KeyPressMask | ButtonPressMask,
-                        &e) && QUIT(e,k))
-                        break;
-                }
-            } else {
-                /* Y2038 BUG! */
-                if (now.tv_sec < then.tv_sec ||
-                    (now.tv_sec == then.tv_sec && now.tv_usec < then.tv_usec))
-                {
-                    int quit = FALSE;
-                    long seconds_to_go = then.tv_sec - now.tv_sec;
-                    long usleep_usec;
-
-                    /* basically chew up most of remaining loop-interval with
-                     *  calls to sleep(1) interleaved with checks for quit
-                     *  events, but also recalc time-to-go periodically; when
-                     *  done, clean up any remaining time with usleep() call
-                     *  (could also use SIGALRM, but signals are a pain...) */
-                    while (seconds_to_go-- > 1) {
-                        int seconds_done = 0;
-
-                        for (i = seconds_to_go;  i > 0 && !quit;  --i) {
-                            sleep(1);
-                            /* GRR BUG:  need to check for Expose and redraw */
-                            if (XCheckMaskEvent(display, KeyPressMask |
-                                ButtonPressMask, &e) && QUIT(e,k))
-                                quit = TRUE;
-                            if (++seconds_done > 1000)
-                                break;   /* time to redo seconds_to_go meas. */
-                        }
-                        if (quit)
-                            break;
-
-                        /* OK, more than 1000 seconds since last check:
-                         *  correct the time-to-go measurement for drift */
-                        if (gettimeofday(&now, NULL) == 0) {
-                            if (now.tv_sec >= then.tv_sec)
-                                break;
-                            seconds_to_go = then.tv_sec - now.tv_sec;
-                        } else
-                            ++seconds_to_go;  /* restore what we subtracted */
-                    }
-                    if (quit)
-                        break;   /* breaks outer do-loop, skips redisplay */
-
-                    /* since difference between "now" and "then" is already
-                     *  eaten up to within a couple of seconds, don't need to
-                     *  worry about overflow--but might have overshot (neg.) */
-                    if (gettimeofday(&now, NULL) == 0) {
-                        usleep_usec = 1000000L*(then.tv_sec - now.tv_sec) +
-                          then.tv_usec - now.tv_usec;
-                        if (usleep_usec > 0)
-                            usleep((ulg)usleep_usec);
-                    }
-                }
-            }
-
-            /* composite image against new background and display (note that
-             *  we do not take into account the time spent doing this...) */
-            rpng2_x_redisplay_image (0, 0, rpng2_info.width, rpng2_info.height);
-        }
-
-    } else /* FALL THROUGH and do the normal thing */
-
-#endif /* FEATURE_LOOP */
-
-    /* wait for the user to tell us when to quit */
-
-    if (rpng2_info.state >= kWindowInit) {
-        Trace((stderr, "entering final wait-for-quit-event loop\n"))
-        do {
-            XNextEvent(display, &e);
-            if (e.type == Expose) {
-                XExposeEvent *ex = (XExposeEvent *)&e;
-                rpng2_x_redisplay_image (ex->x, ex->y, ex->width, ex->height);
-            }
-        } while (!QUIT(e,k));
-    } else {
-        fprintf(stderr, PROGNAME ":  init callback never called:  probable "
-          "libpng error while decoding PNG metadata\n");
-        exit(4);
-    }
-
-
-    /* we're done:  clean up all image and X resources and go away */
-
-    Trace((stderr, "about to call rpng2_x_cleanup()\n"))
-    rpng2_x_cleanup();
-
-    return 0;
-}
-
-
-
-
-
-/* this function is called by readpng2_info_callback() in readpng2.c, which
- * in turn is called by libpng after all of the pre-IDAT chunks have been
- * read and processed--i.e., we now have enough info to finish initializing */
-
-static void rpng2_x_init(void)
-{
-    ulg i;
-    ulg rowbytes = rpng2_info.rowbytes;
-
-    Trace((stderr, "beginning rpng2_x_init()\n"))
-    Trace((stderr, "  rowbytes = %d\n", rpng2_info.rowbytes))
-    Trace((stderr, "  width  = %ld\n", rpng2_info.width))
-    Trace((stderr, "  height = %ld\n", rpng2_info.height))
-
-    rpng2_info.image_data = (uch *)malloc(rowbytes * rpng2_info.height);
-    if (!rpng2_info.image_data) {
-        readpng2_cleanup(&rpng2_info);
-        return;
-    }
-
-    rpng2_info.row_pointers = (uch **)malloc(rpng2_info.height * sizeof(uch *));
-    if (!rpng2_info.row_pointers) {
-        free(rpng2_info.image_data);
-        rpng2_info.image_data = NULL;
-        readpng2_cleanup(&rpng2_info);
-        return;
-    }
-
-    for (i = 0;  i < rpng2_info.height;  ++i)
-        rpng2_info.row_pointers[i] = rpng2_info.image_data + i*rowbytes;
-
-
-    /* do the basic X initialization stuff, make the window, and fill it with
-     * the user-specified, file-specified or default background color or
-     * pattern */
-
-    if (rpng2_x_create_window()) {
-
-        /* GRR TEMPORARY HACK:  this is fundamentally no different from cases
-         * above; libpng should longjmp() back to us when png_ptr goes away.
-         * If we/it segfault instead, seems like a libpng bug... */
-
-        /* we're here via libpng callback, so if window fails, clean and bail */
-        readpng2_cleanup(&rpng2_info);
-        rpng2_x_cleanup();
-        exit(2);
-    }
-
-    rpng2_info.state = kWindowInit;
-}
-
-
-
-
-
-static int rpng2_x_create_window(void)
-{
-    ulg bg_red   = rpng2_info.bg_red;
-    ulg bg_green = rpng2_info.bg_green;
-    ulg bg_blue  = rpng2_info.bg_blue;
-    ulg bg_pixel = 0L;
-    ulg attrmask;
-    int need_colormap = FALSE;
-    int screen, pad;
-    uch *xdata;
-    Window root;
-    XEvent e;
-    XGCValues gcvalues;
-    XSetWindowAttributes attr;
-    XTextProperty windowName, *pWindowName = &windowName;
-    XTextProperty iconName, *pIconName = &iconName;
-    XVisualInfo visual_info;
-    XSizeHints *size_hints;
-    XWMHints *wm_hints;
-    XClassHint *class_hints;
-
-
-    Trace((stderr, "beginning rpng2_x_create_window()\n"))
-
-    screen = DefaultScreen(display);
-    depth = DisplayPlanes(display, screen);
-    root = RootWindow(display, screen);
-
-#ifdef DEBUG
-    XSynchronize(display, True);
-#endif
-
-    if (depth != 16 && depth != 24 && depth != 32) {
-        int visuals_matched = 0;
-
-        Trace((stderr, "default depth is %d:  checking other visuals\n",
-          depth))
-
-        /* 24-bit first */
-        visual_info.screen = screen;
-        visual_info.depth = 24;
-        visual_list = XGetVisualInfo(display,
-          VisualScreenMask | VisualDepthMask, &visual_info, &visuals_matched);
-        if (visuals_matched == 0) {
-/* GRR:  add 15-, 16- and 32-bit TrueColor visuals (also DirectColor?) */
-            fprintf(stderr, "default screen depth %d not supported, and no"
-              " 24-bit visuals found\n", depth);
-            return 2;
-        }
-        Trace((stderr, "XGetVisualInfo() returned %d 24-bit visuals\n",
-          visuals_matched))
-        visual = visual_list[0].visual;
-        depth = visual_list[0].depth;
-/*
-        colormap_size = visual_list[0].colormap_size;
-        visual_class = visual->class;
-        visualID = XVisualIDFromVisual(visual);
- */
-        have_nondefault_visual = TRUE;
-        need_colormap = TRUE;
-    } else {
-        XMatchVisualInfo(display, screen, depth, TrueColor, &visual_info);
-        visual = visual_info.visual;
-    }
-
-    RMask = visual->red_mask;
-    GMask = visual->green_mask;
-    BMask = visual->blue_mask;
-
-/* GRR:  add/check 8-bit support */
-    if (depth == 8 || need_colormap) {
-        colormap = XCreateColormap(display, root, visual, AllocNone);
-        if (!colormap) {
-            fprintf(stderr, "XCreateColormap() failed\n");
-            return 2;
-        }
-        have_colormap = TRUE;
-        if (depth == 8)
-            bg_image = FALSE;   /* gradient just wastes palette entries */
-    }
-    if (depth == 15 || depth == 16) {
-        RShift = 15 - rpng2_x_msb(RMask);    /* these are right-shifts */
-        GShift = 15 - rpng2_x_msb(GMask);
-        BShift = 15 - rpng2_x_msb(BMask);
-    } else if (depth > 16) {
-        RShift = rpng2_x_msb(RMask) - 7;     /* these are left-shifts */
-        GShift = rpng2_x_msb(GMask) - 7;
-        BShift = rpng2_x_msb(BMask) - 7;
-    }
-    if (depth >= 15 && (RShift < 0 || GShift < 0 || BShift < 0)) {
-        fprintf(stderr, "rpng2 internal logic error:  negative X shift(s)!\n");
-        return 2;
-    }
-
-/*---------------------------------------------------------------------------
-    Finally, create the window.
-  ---------------------------------------------------------------------------*/
-
-    attr.backing_store = Always;
-    attr.event_mask = ExposureMask | KeyPressMask | ButtonPressMask;
-    attrmask = CWBackingStore | CWEventMask;
-    if (have_nondefault_visual) {
-        attr.colormap = colormap;
-        attr.background_pixel = 0;
-        attr.border_pixel = 1;
-        attrmask |= CWColormap | CWBackPixel | CWBorderPixel;
-    }
-
-    window = XCreateWindow(display, root, 0, 0, rpng2_info.width,
-      rpng2_info.height, 0, depth, InputOutput, visual, attrmask, &attr);
-
-    if (window == None) {
-        fprintf(stderr, "XCreateWindow() failed\n");
-        return 2;
-    } else
-        have_window = TRUE;
-
-    if (depth == 8)
-        XSetWindowColormap(display, window, colormap);
-
-    if (!XStringListToTextProperty(&window_name, 1, pWindowName))
-        pWindowName = NULL;
-    if (!XStringListToTextProperty(&icon_name, 1, pIconName))
-        pIconName = NULL;
-
-    /* OK if either hints allocation fails; XSetWMProperties() allows NULLs */
-
-    if ((size_hints = XAllocSizeHints()) != NULL) {
-        /* window will not be resizable */
-        size_hints->flags = PMinSize | PMaxSize;
-        size_hints->min_width = size_hints->max_width = (int)rpng2_info.width;
-        size_hints->min_height = size_hints->max_height =
-          (int)rpng2_info.height;
-    }
-
-    if ((wm_hints = XAllocWMHints()) != NULL) {
-        wm_hints->initial_state = NormalState;
-        wm_hints->input = True;
-     /* wm_hints->icon_pixmap = icon_pixmap; */
-        wm_hints->flags = StateHint | InputHint  /* | IconPixmapHint */ ;
-    }
-
-    if ((class_hints = XAllocClassHint()) != NULL) {
-        class_hints->res_name = res_name;
-        class_hints->res_class = res_class;
-    }
-
-    XSetWMProperties(display, window, pWindowName, pIconName, NULL, 0,
-      size_hints, wm_hints, class_hints);
-
-    /* various properties and hints no longer needed; free memory */
-    if (pWindowName)
-       XFree(pWindowName->value);
-    if (pIconName)
-       XFree(pIconName->value);
-    if (size_hints)
-        XFree(size_hints);
-    if (wm_hints)
-       XFree(wm_hints);
-    if (class_hints)
-       XFree(class_hints);
-
-    XMapWindow(display, window);
-
-    gc = XCreateGC(display, window, 0, &gcvalues);
-    have_gc = TRUE;
-
-/*---------------------------------------------------------------------------
-    Allocate memory for the X- and display-specific version of the image.
-  ---------------------------------------------------------------------------*/
-
-    if (depth == 24 || depth == 32) {
-        xdata = (uch *)malloc(4*rpng2_info.width*rpng2_info.height);
-        pad = 32;
-    } else if (depth == 16) {
-        xdata = (uch *)malloc(2*rpng2_info.width*rpng2_info.height);
-        pad = 16;
-    } else /* depth == 8 */ {
-        xdata = (uch *)malloc(rpng2_info.width*rpng2_info.height);
-        pad = 8;
-    }
-
-    if (!xdata) {
-        fprintf(stderr, PROGNAME ":  unable to allocate image memory\n");
-        return 4;
-    }
-
-    ximage = XCreateImage(display, visual, depth, ZPixmap, 0,
-      (char *)xdata, rpng2_info.width, rpng2_info.height, pad, 0);
-
-    if (!ximage) {
-        fprintf(stderr, PROGNAME ":  XCreateImage() failed\n");
-        free(xdata);
-        return 3;
-    }
-
-    /* to avoid testing the byte order every pixel (or doubling the size of
-     * the drawing routine with a giant if-test), we arbitrarily set the byte
-     * order to MSBFirst and let Xlib worry about inverting things on little-
-     * endian machines (e.g., Linux/x86, old VAXen, etc.)--this is not the
-     * most efficient approach (the giant if-test would be better), but in
-     * the interest of clarity, we'll take the easy way out... */
-
-    ximage->byte_order = MSBFirst;
-
-/*---------------------------------------------------------------------------
-    Fill window with the specified background color (default is black) or
-    faked "background image" (but latter is disabled if 8-bit; gradients
-    just waste palette entries).
-  ---------------------------------------------------------------------------*/
-
-    if (bg_image)
-        rpng2_x_load_bg_image();    /* resets bg_image if fails */
-
-    if (!bg_image) {
-        if (depth == 24 || depth == 32) {
-            bg_pixel = (bg_red   << RShift) |
-                       (bg_green << GShift) |
-                       (bg_blue  << BShift);
-        } else if (depth == 16) {
-            bg_pixel = (((bg_red   << 8) >> RShift) & RMask) |
-                       (((bg_green << 8) >> GShift) & GMask) |
-                       (((bg_blue  << 8) >> BShift) & BMask);
-        } else /* depth == 8 */ {
-
-            /* GRR:  add 8-bit support */
-
-        }
-        XSetForeground(display, gc, bg_pixel);
-        XFillRectangle(display, window, gc, 0, 0, rpng2_info.width,
-          rpng2_info.height);
-    }
-
-/*---------------------------------------------------------------------------
-    Wait for first Expose event to do any drawing, then flush and return.
-  ---------------------------------------------------------------------------*/
-
-    do
-        XNextEvent(display, &e);
-    while (e.type != Expose || e.xexpose.count);
-
-    XFlush(display);
-
-    return 0;
-
-} /* end function rpng2_x_create_window() */
-
-
-
-
-
-static int rpng2_x_load_bg_image(void)
-{
-    uch *src;
-    char *dest;
-    uch r1, r2, g1, g2, b1, b2;
-    uch r1_inv, r2_inv, g1_inv, g2_inv, b1_inv, b2_inv;
-    int k, hmax, max;
-    int xidx, yidx, yidx_max;
-    int even_odd_vert, even_odd_horiz, even_odd;
-    int invert_gradient2 = (bg[pat].type & 0x08);
-    int invert_column;
-    int ximage_rowbytes = ximage->bytes_per_line;
-    ulg i, row;
-    ulg pixel;
-
-/*---------------------------------------------------------------------------
-    Allocate buffer for fake background image to be used with transparent
-    images; if this fails, revert to plain background color.
-  ---------------------------------------------------------------------------*/
-
-    bg_rowbytes = 3 * rpng2_info.width;
-    bg_data = (uch *)malloc(bg_rowbytes * rpng2_info.height);
-    if (!bg_data) {
-        fprintf(stderr, PROGNAME
-          ":  unable to allocate memory for background image\n");
-        bg_image = 0;
-        return 1;
-    }
-
-    bgscale = (pat == 0)? 8 : bgscale_default;
-    yidx_max = bgscale - 1;
-
-/*---------------------------------------------------------------------------
-    Vertical gradients (ramps) in NxN squares, alternating direction and
-    colors (N == bgscale).
-  ---------------------------------------------------------------------------*/
-
-    if ((bg[pat].type & 0x07) == 0) {
-        uch r1_min  = rgb[bg[pat].rgb1_min].r;
-        uch g1_min  = rgb[bg[pat].rgb1_min].g;
-        uch b1_min  = rgb[bg[pat].rgb1_min].b;
-        uch r2_min  = rgb[bg[pat].rgb2_min].r;
-        uch g2_min  = rgb[bg[pat].rgb2_min].g;
-        uch b2_min  = rgb[bg[pat].rgb2_min].b;
-        int r1_diff = rgb[bg[pat].rgb1_max].r - r1_min;
-        int g1_diff = rgb[bg[pat].rgb1_max].g - g1_min;
-        int b1_diff = rgb[bg[pat].rgb1_max].b - b1_min;
-        int r2_diff = rgb[bg[pat].rgb2_max].r - r2_min;
-        int g2_diff = rgb[bg[pat].rgb2_max].g - g2_min;
-        int b2_diff = rgb[bg[pat].rgb2_max].b - b2_min;
-
-        for (row = 0;  row < rpng2_info.height;  ++row) {
-            yidx = (int)(row % bgscale);
-            even_odd_vert = (int)((row / bgscale) & 1);
-
-            r1 = r1_min + (r1_diff * yidx) / yidx_max;
-            g1 = g1_min + (g1_diff * yidx) / yidx_max;
-            b1 = b1_min + (b1_diff * yidx) / yidx_max;
-            r1_inv = r1_min + (r1_diff * (yidx_max-yidx)) / yidx_max;
-            g1_inv = g1_min + (g1_diff * (yidx_max-yidx)) / yidx_max;
-            b1_inv = b1_min + (b1_diff * (yidx_max-yidx)) / yidx_max;
-
-            r2 = r2_min + (r2_diff * yidx) / yidx_max;
-            g2 = g2_min + (g2_diff * yidx) / yidx_max;
-            b2 = b2_min + (b2_diff * yidx) / yidx_max;
-            r2_inv = r2_min + (r2_diff * (yidx_max-yidx)) / yidx_max;
-            g2_inv = g2_min + (g2_diff * (yidx_max-yidx)) / yidx_max;
-            b2_inv = b2_min + (b2_diff * (yidx_max-yidx)) / yidx_max;
-
-            dest = (char *)bg_data + row*bg_rowbytes;
-            for (i = 0;  i < rpng2_info.width;  ++i) {
-                even_odd_horiz = (int)((i / bgscale) & 1);
-                even_odd = even_odd_vert ^ even_odd_horiz;
-                invert_column =
-                  (even_odd_horiz && (bg[pat].type & 0x10));
-                if (even_odd == 0) {        /* gradient #1 */
-                    if (invert_column) {
-                        *dest++ = r1_inv;
-                        *dest++ = g1_inv;
-                        *dest++ = b1_inv;
-                    } else {
-                        *dest++ = r1;
-                        *dest++ = g1;
-                        *dest++ = b1;
-                    }
-                } else {                    /* gradient #2 */
-                    if ((invert_column && invert_gradient2) ||
-                        (!invert_column && !invert_gradient2))
-                    {
-                        *dest++ = r2;       /* not inverted or */
-                        *dest++ = g2;       /*  doubly inverted */
-                        *dest++ = b2;
-                    } else {
-                        *dest++ = r2_inv;
-                        *dest++ = g2_inv;   /* singly inverted */
-                        *dest++ = b2_inv;
-                    }
-                }
-            }
-        }
-
-/*---------------------------------------------------------------------------
-    Soft gradient-diamonds with scale = bgscale.  Code contributed by Adam
-    M. Costello.
-  ---------------------------------------------------------------------------*/
-
-    } else if ((bg[pat].type & 0x07) == 1) {
-
-        hmax = (bgscale-1)/2;   /* half the max weight of a color */
-        max = 2*hmax;           /* the max weight of a color */
-
-        r1 = rgb[bg[pat].rgb1_max].r;
-        g1 = rgb[bg[pat].rgb1_max].g;
-        b1 = rgb[bg[pat].rgb1_max].b;
-        r2 = rgb[bg[pat].rgb2_max].r;
-        g2 = rgb[bg[pat].rgb2_max].g;
-        b2 = rgb[bg[pat].rgb2_max].b;
-
-        for (row = 0;  row < rpng2_info.height;  ++row) {
-            yidx = (int)(row % bgscale);
-            if (yidx > hmax)
-                yidx = bgscale-1 - yidx;
-            dest = (char *)bg_data + row*bg_rowbytes;
-            for (i = 0;  i < rpng2_info.width;  ++i) {
-                xidx = (int)(i % bgscale);
-                if (xidx > hmax)
-                    xidx = bgscale-1 - xidx;
-                k = xidx + yidx;
-                *dest++ = (k*r1 + (max-k)*r2) / max;
-                *dest++ = (k*g1 + (max-k)*g2) / max;
-                *dest++ = (k*b1 + (max-k)*b2) / max;
-            }
-        }
-
-/*---------------------------------------------------------------------------
-    Radial "starburst" with azimuthal sinusoids; [eventually number of sinu-
-    soids will equal bgscale?].  This one is slow but very cool.  Code con-
-    tributed by Pieter S. van der Meulen (originally in Smalltalk).
-  ---------------------------------------------------------------------------*/
-
-    } else if ((bg[pat].type & 0x07) == 2) {
-        uch ch;
-        int ii, x, y, hw, hh, grayspot;
-        double freq, rotate, saturate, gray, intensity;
-        double angle=0.0, aoffset=0.0, maxDist, dist;
-        double red=0.0, green=0.0, blue=0.0, hue, s, v, f, p, q, t;
-
-        fprintf(stderr, "%s:  computing radial background...",
-          PROGNAME);
-        fflush(stderr);
-
-        hh = (int)(rpng2_info.height / 2);
-        hw = (int)(rpng2_info.width / 2);
-
-        /* variables for radial waves:
-         *   aoffset:  number of degrees to rotate hue [CURRENTLY NOT USED]
-         *   freq:  number of color beams originating from the center
-         *   grayspot:  size of the graying center area (anti-alias)
-         *   rotate:  rotation of the beams as a function of radius
-         *   saturate:  saturation of beams' shape azimuthally
-         */
-        angle = CLIP(angle, 0.0, 360.0);
-        grayspot = CLIP(bg[pat].bg_gray, 1, (hh + hw));
-        freq = MAX((double)bg[pat].bg_freq, 0.0);
-        saturate = (double)bg[pat].bg_bsat * 0.1;
-        rotate = (double)bg[pat].bg_brot * 0.1;
-        gray = 0.0;
-        intensity = 0.0;
-        maxDist = (double)((hw*hw) + (hh*hh));
-
-        for (row = 0;  row < rpng2_info.height;  ++row) {
-            y = (int)(row - hh);
-            dest = (char *)bg_data + row*bg_rowbytes;
-            for (i = 0;  i < rpng2_info.width;  ++i) {
-                x = (int)(i - hw);
-                angle = (x == 0)? PI_2 : atan((double)y / (double)x);
-                gray = (double)MAX(ABS(y), ABS(x)) / grayspot;
-                gray = MIN(1.0, gray);
-                dist = (double)((x*x) + (y*y)) / maxDist;
-                intensity = cos((angle+(rotate*dist*PI)) * freq) *
-                  gray * saturate;
-                intensity = (MAX(MIN(intensity,1.0),-1.0) + 1.0) * 0.5;
-                hue = (angle + PI) * INV_PI_360 + aoffset;
-                s = gray * ((double)(ABS(x)+ABS(y)) / (double)(hw + hh));
-                s = MIN(MAX(s,0.0), 1.0);
-                v = MIN(MAX(intensity,0.0), 1.0);
-
-                if (s == 0.0) {
-                    ch = (uch)(v * 255.0);
-                    *dest++ = ch;
-                    *dest++ = ch;
-                    *dest++ = ch;
-                } else {
-                    if ((hue < 0.0) || (hue >= 360.0))
-                        hue -= (((int)(hue / 360.0)) * 360.0);
-                    hue /= 60.0;
-                    ii = (int)hue;
-                    f = hue - (double)ii;
-                    p = (1.0 - s) * v;
-                    q = (1.0 - (s * f)) * v;
-                    t = (1.0 - (s * (1.0 - f))) * v;
-                    if      (ii == 0) { red = v; green = t; blue = p; }
-                    else if (ii == 1) { red = q; green = v; blue = p; }
-                    else if (ii == 2) { red = p; green = v; blue = t; }
-                    else if (ii == 3) { red = p; green = q; blue = v; }
-                    else if (ii == 4) { red = t; green = p; blue = v; }
-                    else if (ii == 5) { red = v; green = p; blue = q; }
-                    *dest++ = (uch)(red * 255.0);
-                    *dest++ = (uch)(green * 255.0);
-                    *dest++ = (uch)(blue * 255.0);
-                }
-            }
-        }
-        fprintf(stderr, "done.\n");
-        fflush(stderr);
-    }
-
-/*---------------------------------------------------------------------------
-    Blast background image to display buffer before beginning PNG decode.
-  ---------------------------------------------------------------------------*/
-
-    if (depth == 24 || depth == 32) {
-        ulg red, green, blue;
-        int bpp = ximage->bits_per_pixel;
-
-        for (row = 0;  row < rpng2_info.height;  ++row) {
-            src = bg_data + row*bg_rowbytes;
-            dest = ximage->data + row*ximage_rowbytes;
-            if (bpp == 32) {	/* slightly optimized version */
-                for (i = rpng2_info.width;  i > 0;  --i) {
-                    red   = *src++;
-                    green = *src++;
-                    blue  = *src++;
-                    pixel = (red   << RShift) |
-                            (green << GShift) |
-                            (blue  << BShift);
-                    /* recall that we set ximage->byte_order = MSBFirst above */
-                    *dest++ = (char)((pixel >> 24) & 0xff);
-                    *dest++ = (char)((pixel >> 16) & 0xff);
-                    *dest++ = (char)((pixel >>  8) & 0xff);
-                    *dest++ = (char)( pixel        & 0xff);
-                }
-            } else {
-                for (i = rpng2_info.width;  i > 0;  --i) {
-                    red   = *src++;
-                    green = *src++;
-                    blue  = *src++;
-                    pixel = (red   << RShift) |
-                            (green << GShift) |
-                            (blue  << BShift);
-                    /* recall that we set ximage->byte_order = MSBFirst above */
-                    /* GRR BUG?  this assumes bpp == 24 & bits are packed low */
-                    /*           (probably need to use RShift, RMask, etc.) */
-                    *dest++ = (char)((pixel >> 16) & 0xff);
-                    *dest++ = (char)((pixel >>  8) & 0xff);
-                    *dest++ = (char)( pixel        & 0xff);
-                }
-            }
-        }
-
-    } else if (depth == 16) {
-        ush red, green, blue;
-
-        for (row = 0;  row < rpng2_info.height;  ++row) {
-            src = bg_data + row*bg_rowbytes;
-            dest = ximage->data + row*ximage_rowbytes;
-            for (i = rpng2_info.width;  i > 0;  --i) {
-                red   = ((ush)(*src) << 8);  ++src;
-                green = ((ush)(*src) << 8);  ++src;
-                blue  = ((ush)(*src) << 8);  ++src;
-                pixel = ((red   >> RShift) & RMask) |
-                        ((green >> GShift) & GMask) |
-                        ((blue  >> BShift) & BMask);
-                /* recall that we set ximage->byte_order = MSBFirst above */
-                *dest++ = (char)((pixel >>  8) & 0xff);
-                *dest++ = (char)( pixel        & 0xff);
-            }
-        }
-
-    } else /* depth == 8 */ {
-
-        /* GRR:  add 8-bit support */
-
-    }
-
-    XPutImage(display, window, gc, ximage, 0, 0, 0, 0, rpng2_info.width,
-      rpng2_info.height);
-
-    return 0;
-
-} /* end function rpng2_x_load_bg_image() */
-
-
-
-
-
-static void rpng2_x_display_row(ulg row)
-{
-    uch bg_red   = rpng2_info.bg_red;
-    uch bg_green = rpng2_info.bg_green;
-    uch bg_blue  = rpng2_info.bg_blue;
-    uch *src, *src2=NULL;
-    char *dest;
-    uch r, g, b, a;
-    int ximage_rowbytes = ximage->bytes_per_line;
-    ulg i, pixel;
-    static int rows=0, prevpass=(-1);
-    static ulg firstrow;
-
-/*---------------------------------------------------------------------------
-    rows and firstrow simply track how many rows (and which ones) have not
-    yet been displayed; alternatively, we could call XPutImage() for every
-    row and not bother with the records-keeping.
-  ---------------------------------------------------------------------------*/
-
-    Trace((stderr, "beginning rpng2_x_display_row()\n"))
-
-    if (rpng2_info.pass != prevpass) {
-        if (pause_after_pass && rpng2_info.pass > 0) {
-            XEvent e;
-            KeySym k;
-
-            fprintf(stderr,
-              "%s:  end of pass %d of 7; click in image window to continue\n",
-              PROGNAME, prevpass + 1);
-            do
-                XNextEvent(display, &e);
-            while (!QUIT(e,k));
-        }
-        fprintf(stderr, "%s:  pass %d of 7\r", PROGNAME, rpng2_info.pass + 1);
-        fflush(stderr);
-        prevpass = rpng2_info.pass;
-    }
-
-    if (rows == 0)
-        firstrow = row;   /* first row that is not yet displayed */
-
-    ++rows;   /* count of rows received but not yet displayed */
-
-/*---------------------------------------------------------------------------
-    Aside from the use of the rpng2_info struct, the lack of an outer loop
-    (over rows) and moving the XPutImage() call outside the "if (depth)"
-    tests, this routine is identical to rpng_x_display_image() in the non-
-    progressive version of the program.
-  ---------------------------------------------------------------------------*/
-
-    if (depth == 24 || depth == 32) {
-        ulg red, green, blue;
-        int bpp = ximage->bits_per_pixel;
-
-        src = rpng2_info.image_data + row*rpng2_info.rowbytes;
-        if (bg_image)
-            src2 = bg_data + row*bg_rowbytes;
-        dest = ximage->data + row*ximage_rowbytes;
-        if (rpng2_info.channels == 3) {
-            for (i = rpng2_info.width;  i > 0;  --i) {
-                red   = *src++;
-                green = *src++;
-                blue  = *src++;
-                pixel = (red   << RShift) |
-                        (green << GShift) |
-                        (blue  << BShift);
-                /* recall that we set ximage->byte_order = MSBFirst above */
-                if (bpp == 32) {
-                    *dest++ = (char)((pixel >> 24) & 0xff);
-                    *dest++ = (char)((pixel >> 16) & 0xff);
-                    *dest++ = (char)((pixel >>  8) & 0xff);
-                    *dest++ = (char)( pixel        & 0xff);
-                } else {
-                    /* GRR BUG?  this assumes bpp == 24 & bits are packed low */
-                    /*           (probably need to use RShift, RMask, etc.) */
-                    *dest++ = (char)((pixel >> 16) & 0xff);
-                    *dest++ = (char)((pixel >>  8) & 0xff);
-                    *dest++ = (char)( pixel        & 0xff);
-                }
-            }
-        } else /* if (rpng2_info.channels == 4) */ {
-            for (i = rpng2_info.width;  i > 0;  --i) {
-                r = *src++;
-                g = *src++;
-                b = *src++;
-                a = *src++;
-                if (bg_image) {
-                    bg_red   = *src2++;
-                    bg_green = *src2++;
-                    bg_blue  = *src2++;
-                }
-                if (a == 255) {
-                    red   = r;
-                    green = g;
-                    blue  = b;
-                } else if (a == 0) {
-                    red   = bg_red;
-                    green = bg_green;
-                    blue  = bg_blue;
-                } else {
-                    /* this macro (from png.h) composites the foreground
-                     * and background values and puts the result into the
-                     * first argument */
-                    alpha_composite(red,   r, a, bg_red);
-                    alpha_composite(green, g, a, bg_green);
-                    alpha_composite(blue,  b, a, bg_blue);
-                }
-                pixel = (red   << RShift) |
-                        (green << GShift) |
-                        (blue  << BShift);
-                /* recall that we set ximage->byte_order = MSBFirst above */
-                if (bpp == 32) {
-                    *dest++ = (char)((pixel >> 24) & 0xff);
-                    *dest++ = (char)((pixel >> 16) & 0xff);
-                    *dest++ = (char)((pixel >>  8) & 0xff);
-                    *dest++ = (char)( pixel        & 0xff);
-                } else {
-                    /* GRR BUG?  this assumes bpp == 24 & bits are packed low */
-                    /*           (probably need to use RShift, RMask, etc.) */
-                    *dest++ = (char)((pixel >> 16) & 0xff);
-                    *dest++ = (char)((pixel >>  8) & 0xff);
-                    *dest++ = (char)( pixel        & 0xff);
-                }
-            }
-        }
-
-    } else if (depth == 16) {
-        ush red, green, blue;
-
-        src = rpng2_info.row_pointers[row];
-        if (bg_image)
-            src2 = bg_data + row*bg_rowbytes;
-        dest = ximage->data + row*ximage_rowbytes;
-        if (rpng2_info.channels == 3) {
-            for (i = rpng2_info.width;  i > 0;  --i) {
-                red   = ((ush)(*src) << 8);
-                ++src;
-                green = ((ush)(*src) << 8);
-                ++src;
-                blue  = ((ush)(*src) << 8);
-                ++src;
-                pixel = ((red   >> RShift) & RMask) |
-                        ((green >> GShift) & GMask) |
-                        ((blue  >> BShift) & BMask);
-                /* recall that we set ximage->byte_order = MSBFirst above */
-                *dest++ = (char)((pixel >>  8) & 0xff);
-                *dest++ = (char)( pixel        & 0xff);
-            }
-        } else /* if (rpng2_info.channels == 4) */ {
-            for (i = rpng2_info.width;  i > 0;  --i) {
-                r = *src++;
-                g = *src++;
-                b = *src++;
-                a = *src++;
-                if (bg_image) {
-                    bg_red   = *src2++;
-                    bg_green = *src2++;
-                    bg_blue  = *src2++;
-                }
-                if (a == 255) {
-                    red   = ((ush)r << 8);
-                    green = ((ush)g << 8);
-                    blue  = ((ush)b << 8);
-                } else if (a == 0) {
-                    red   = ((ush)bg_red   << 8);
-                    green = ((ush)bg_green << 8);
-                    blue  = ((ush)bg_blue  << 8);
-                } else {
-                    /* this macro (from png.h) composites the foreground
-                     * and background values and puts the result back into
-                     * the first argument (== fg byte here:  safe) */
-                    alpha_composite(r, r, a, bg_red);
-                    alpha_composite(g, g, a, bg_green);
-                    alpha_composite(b, b, a, bg_blue);
-                    red   = ((ush)r << 8);
-                    green = ((ush)g << 8);
-                    blue  = ((ush)b << 8);
-                }
-                pixel = ((red   >> RShift) & RMask) |
-                        ((green >> GShift) & GMask) |
-                        ((blue  >> BShift) & BMask);
-                /* recall that we set ximage->byte_order = MSBFirst above */
-                *dest++ = (char)((pixel >>  8) & 0xff);
-                *dest++ = (char)( pixel        & 0xff);
-            }
-        }
-
-    } else /* depth == 8 */ {
-
-        /* GRR:  add 8-bit support */
-
-    }
-
-
-/*---------------------------------------------------------------------------
-    Display after every 16 rows or when on one of last two rows.  (Region
-    may include previously displayed lines due to interlacing--i.e., not
-    contiguous.  Also, second-to-last row is final one in interlaced images
-    with odd number of rows.)  For demos, flush (and delay) after every 16th
-    row so "sparse" passes don't go twice as fast.
-  ---------------------------------------------------------------------------*/
-
-    if (demo_timing && (row - firstrow >= 16 || row >= rpng2_info.height-2)) {
-        XPutImage(display, window, gc, ximage, 0, (int)firstrow, 0,
-          (int)firstrow, rpng2_info.width, row - firstrow + 1);
-        XFlush(display);
-        rows = 0;
-        usleep(usleep_duration);
-    } else
-    if (!demo_timing && ((rows & 0xf) == 0 || row >= rpng2_info.height-2)) {
-        XPutImage(display, window, gc, ximage, 0, (int)firstrow, 0,
-          (int)firstrow, rpng2_info.width, row - firstrow + 1);
-        XFlush(display);
-        rows = 0;
-    }
-
-}
-
-
-
-
-
-static void rpng2_x_finish_display(void)
-{
-    Trace((stderr, "beginning rpng2_x_finish_display()\n"))
-
-    /* last row has already been displayed by rpng2_x_display_row(), so we
-     * have nothing to do here except set a flag and let the user know that
-     * the image is done */
-
-    rpng2_info.state = kDone;
-    printf(
-      "Done.  Press Q, Esc or mouse button 1 (within image window) to quit.\n");
-    fflush(stdout);
-}
-
-
-
-
-
-static void rpng2_x_redisplay_image(ulg startcol, ulg startrow,
-                                    ulg width, ulg height)
-{
-    uch bg_red   = rpng2_info.bg_red;
-    uch bg_green = rpng2_info.bg_green;
-    uch bg_blue  = rpng2_info.bg_blue;
-    uch *src, *src2=NULL;
-    char *dest;
-    uch r, g, b, a;
-    ulg i, row, lastrow = 0;
-    ulg pixel;
-    int ximage_rowbytes = ximage->bytes_per_line;
-
-
-    Trace((stderr, "beginning display loop (image_channels == %d)\n",
-      rpng2_info.channels))
-    Trace((stderr, "   (width = %ld, rowbytes = %d, ximage_rowbytes = %d)\n",
-      rpng2_info.width, rpng2_info.rowbytes, ximage_rowbytes))
-    Trace((stderr, "   (bpp = %d)\n", ximage->bits_per_pixel))
-    Trace((stderr, "   (byte_order = %s)\n", ximage->byte_order == MSBFirst?
-      "MSBFirst" : (ximage->byte_order == LSBFirst? "LSBFirst" : "unknown")))
-
-/*---------------------------------------------------------------------------
-    Aside from the use of the rpng2_info struct and of src2 (for background
-    image), this routine is identical to rpng_x_display_image() in the non-
-    progressive version of the program--for the simple reason that redisplay
-    of the image against a new background happens after the image is fully
-    decoded and therefore is, by definition, non-progressive.
-  ---------------------------------------------------------------------------*/
-
-    if (depth == 24 || depth == 32) {
-        ulg red, green, blue;
-        int bpp = ximage->bits_per_pixel;
-
-        for (lastrow = row = startrow;  row < startrow+height;  ++row) {
-            src = rpng2_info.image_data + row*rpng2_info.rowbytes;
-            if (bg_image)
-                src2 = bg_data + row*bg_rowbytes;
-            dest = ximage->data + row*ximage_rowbytes;
-            if (rpng2_info.channels == 3) {
-                for (i = rpng2_info.width;  i > 0;  --i) {
-                    red   = *src++;
-                    green = *src++;
-                    blue  = *src++;
-#ifdef NO_24BIT_MASKS
-                    pixel = (red   << RShift) |
-                            (green << GShift) |
-                            (blue  << BShift);
-                    /* recall that we set ximage->byte_order = MSBFirst above */
-                    if (bpp == 32) {
-                        *dest++ = (char)((pixel >> 24) & 0xff);
-                        *dest++ = (char)((pixel >> 16) & 0xff);
-                        *dest++ = (char)((pixel >>  8) & 0xff);
-                        *dest++ = (char)( pixel        & 0xff);
-                    } else {
-                        /* this assumes bpp == 24 & bits are packed low */
-                        /* (probably need to use RShift, RMask, etc.) */
-                        *dest++ = (char)((pixel >> 16) & 0xff);
-                        *dest++ = (char)((pixel >>  8) & 0xff);
-                        *dest++ = (char)( pixel        & 0xff);
-                    }
-#else
-                    red   = (RShift < 0)? red   << (-RShift) : red   >> RShift;
-                    green = (GShift < 0)? green << (-GShift) : green >> GShift;
-                    blue  = (BShift < 0)? blue  << (-BShift) : blue  >> BShift;
-                    pixel = (red & RMask) | (green & GMask) | (blue & BMask);
-                    /* recall that we set ximage->byte_order = MSBFirst above */
-                    if (bpp == 32) {
-                        *dest++ = (char)((pixel >> 24) & 0xff);
-                        *dest++ = (char)((pixel >> 16) & 0xff);
-                        *dest++ = (char)((pixel >>  8) & 0xff);
-                        *dest++ = (char)( pixel        & 0xff);
-                    } else {
-                        /* GRR BUG */
-                        /* this assumes bpp == 24 & bits are packed low */
-                        /* (probably need to use RShift/RMask/etc. here, too) */
-                        *dest++ = (char)((pixel >> 16) & 0xff);
-                        *dest++ = (char)((pixel >>  8) & 0xff);
-                        *dest++ = (char)( pixel        & 0xff);
-                    }
-#endif
-                }
-
-            } else /* if (rpng2_info.channels == 4) */ {
-                for (i = rpng2_info.width;  i > 0;  --i) {
-                    r = *src++;
-                    g = *src++;
-                    b = *src++;
-                    a = *src++;
-                    if (bg_image) {
-                        bg_red   = *src2++;
-                        bg_green = *src2++;
-                        bg_blue  = *src2++;
-                    }
-                    if (a == 255) {
-                        red   = r;
-                        green = g;
-                        blue  = b;
-                    } else if (a == 0) {
-                        red   = bg_red;
-                        green = bg_green;
-                        blue  = bg_blue;
-                    } else {
-                        /* this macro (from png.h) composites the foreground
-                         * and background values and puts the result into the
-                         * first argument */
-                        alpha_composite(red,   r, a, bg_red);
-                        alpha_composite(green, g, a, bg_green);
-                        alpha_composite(blue,  b, a, bg_blue);
-                    }
-#ifdef NO_24BIT_MASKS
-                    pixel = (red   << RShift) |
-                            (green << GShift) |
-                            (blue  << BShift);
-                    /* recall that we set ximage->byte_order = MSBFirst above */
-                    if (bpp == 32) {
-                        *dest++ = (char)((pixel >> 24) & 0xff);
-                        *dest++ = (char)((pixel >> 16) & 0xff);
-                        *dest++ = (char)((pixel >>  8) & 0xff);
-                        *dest++ = (char)( pixel        & 0xff);
-                    } else {
-                        /* this assumes bpp == 24 & bits are packed low */
-                        /* (probably need to use RShift, RMask, etc.) */
-                        *dest++ = (char)((pixel >> 16) & 0xff);
-                        *dest++ = (char)((pixel >>  8) & 0xff);
-                        *dest++ = (char)( pixel        & 0xff);
-                    }
-#else
-                    red   = (RShift < 0)? red   << (-RShift) : red   >> RShift;
-                    green = (GShift < 0)? green << (-GShift) : green >> GShift;
-                    blue  = (BShift < 0)? blue  << (-BShift) : blue  >> BShift;
-                    pixel = (red & RMask) | (green & GMask) | (blue & BMask);
-                    /* recall that we set ximage->byte_order = MSBFirst above */
-                    if (bpp == 32) {
-                        *dest++ = (char)((pixel >> 24) & 0xff);
-                        *dest++ = (char)((pixel >> 16) & 0xff);
-                        *dest++ = (char)((pixel >>  8) & 0xff);
-                        *dest++ = (char)( pixel        & 0xff);
-                    } else {
-                        /* GRR BUG */
-                        /* this assumes bpp == 24 & bits are packed low */
-                        /* (probably need to use RShift/RMask/etc. here, too) */
-                        *dest++ = (char)((pixel >> 16) & 0xff);
-                        *dest++ = (char)((pixel >>  8) & 0xff);
-                        *dest++ = (char)( pixel        & 0xff);
-                    }
-#endif
-                }
-            }
-            /* display after every 16 lines */
-            if (((row+1) & 0xf) == 0) {
-                XPutImage(display, window, gc, ximage, 0, (int)lastrow, 0,
-                  (int)lastrow, rpng2_info.width, 16);
-                XFlush(display);
-                lastrow = row + 1;
-            }
-        }
-
-    } else if (depth == 16) {
-        ush red, green, blue;
-
-        for (lastrow = row = startrow;  row < startrow+height;  ++row) {
-            src = rpng2_info.row_pointers[row];
-            if (bg_image)
-                src2 = bg_data + row*bg_rowbytes;
-            dest = ximage->data + row*ximage_rowbytes;
-            if (rpng2_info.channels == 3) {
-                for (i = rpng2_info.width;  i > 0;  --i) {
-                    red   = ((ush)(*src) << 8);
-                    ++src;
-                    green = ((ush)(*src) << 8);
-                    ++src;
-                    blue  = ((ush)(*src) << 8);
-                    ++src;
-                    pixel = ((red   >> RShift) & RMask) |
-                            ((green >> GShift) & GMask) |
-                            ((blue  >> BShift) & BMask);
-                    /* recall that we set ximage->byte_order = MSBFirst above */
-                    *dest++ = (char)((pixel >>  8) & 0xff);
-                    *dest++ = (char)( pixel        & 0xff);
-                }
-            } else /* if (rpng2_info.channels == 4) */ {
-                for (i = rpng2_info.width;  i > 0;  --i) {
-                    r = *src++;
-                    g = *src++;
-                    b = *src++;
-                    a = *src++;
-                    if (bg_image) {
-                        bg_red   = *src2++;
-                        bg_green = *src2++;
-                        bg_blue  = *src2++;
-                    }
-                    if (a == 255) {
-                        red   = ((ush)r << 8);
-                        green = ((ush)g << 8);
-                        blue  = ((ush)b << 8);
-                    } else if (a == 0) {
-                        red   = ((ush)bg_red   << 8);
-                        green = ((ush)bg_green << 8);
-                        blue  = ((ush)bg_blue  << 8);
-                    } else {
-                        /* this macro (from png.h) composites the foreground
-                         * and background values and puts the result back into
-                         * the first argument (== fg byte here:  safe) */
-                        alpha_composite(r, r, a, bg_red);
-                        alpha_composite(g, g, a, bg_green);
-                        alpha_composite(b, b, a, bg_blue);
-                        red   = ((ush)r << 8);
-                        green = ((ush)g << 8);
-                        blue  = ((ush)b << 8);
-                    }
-                    pixel = ((red   >> RShift) & RMask) |
-                            ((green >> GShift) & GMask) |
-                            ((blue  >> BShift) & BMask);
-                    /* recall that we set ximage->byte_order = MSBFirst above */
-                    *dest++ = (char)((pixel >>  8) & 0xff);
-                    *dest++ = (char)( pixel        & 0xff);
-                }
-            }
-            /* display after every 16 lines */
-            if (((row+1) & 0xf) == 0) {
-                XPutImage(display, window, gc, ximage, 0, (int)lastrow, 0,
-                  (int)lastrow, rpng2_info.width, 16);
-                XFlush(display);
-                lastrow = row + 1;
-            }
-        }
-
-    } else /* depth == 8 */ {
-
-        /* GRR:  add 8-bit support */
-
-    }
-
-    Trace((stderr, "calling final XPutImage()\n"))
-    if (lastrow < startrow+height) {
-        XPutImage(display, window, gc, ximage, 0, (int)lastrow, 0,
-          (int)lastrow, rpng2_info.width, rpng2_info.height-lastrow);
-        XFlush(display);
-    }
-
-} /* end function rpng2_x_redisplay_image() */
-
-
-
-
-
-#ifdef FEATURE_LOOP
-
-static void rpng2_x_reload_bg_image(void)
-{
-    char *dest;
-    uch r1, r2, g1, g2, b1, b2;
-    uch r1_inv, r2_inv, g1_inv, g2_inv, b1_inv, b2_inv;
-    int k, hmax, max;
-    int xidx, yidx, yidx_max;
-    int even_odd_vert, even_odd_horiz, even_odd;
-    int invert_gradient2 = (bg[pat].type & 0x08);
-    int invert_column;
-    ulg i, row;
-
-
-    bgscale = (pat == 0)? 8 : bgscale_default;
-    yidx_max = bgscale - 1;
-
-/*---------------------------------------------------------------------------
-    Vertical gradients (ramps) in NxN squares, alternating direction and
-    colors (N == bgscale).
-  ---------------------------------------------------------------------------*/
-
-    if ((bg[pat].type & 0x07) == 0) {
-        uch r1_min  = rgb[bg[pat].rgb1_min].r;
-        uch g1_min  = rgb[bg[pat].rgb1_min].g;
-        uch b1_min  = rgb[bg[pat].rgb1_min].b;
-        uch r2_min  = rgb[bg[pat].rgb2_min].r;
-        uch g2_min  = rgb[bg[pat].rgb2_min].g;
-        uch b2_min  = rgb[bg[pat].rgb2_min].b;
-        int r1_diff = rgb[bg[pat].rgb1_max].r - r1_min;
-        int g1_diff = rgb[bg[pat].rgb1_max].g - g1_min;
-        int b1_diff = rgb[bg[pat].rgb1_max].b - b1_min;
-        int r2_diff = rgb[bg[pat].rgb2_max].r - r2_min;
-        int g2_diff = rgb[bg[pat].rgb2_max].g - g2_min;
-        int b2_diff = rgb[bg[pat].rgb2_max].b - b2_min;
-
-        for (row = 0;  row < rpng2_info.height;  ++row) {
-            yidx = (int)(row % bgscale);
-            even_odd_vert = (int)((row / bgscale) & 1);
-
-            r1 = r1_min + (r1_diff * yidx) / yidx_max;
-            g1 = g1_min + (g1_diff * yidx) / yidx_max;
-            b1 = b1_min + (b1_diff * yidx) / yidx_max;
-            r1_inv = r1_min + (r1_diff * (yidx_max-yidx)) / yidx_max;
-            g1_inv = g1_min + (g1_diff * (yidx_max-yidx)) / yidx_max;
-            b1_inv = b1_min + (b1_diff * (yidx_max-yidx)) / yidx_max;
-
-            r2 = r2_min + (r2_diff * yidx) / yidx_max;
-            g2 = g2_min + (g2_diff * yidx) / yidx_max;
-            b2 = b2_min + (b2_diff * yidx) / yidx_max;
-            r2_inv = r2_min + (r2_diff * (yidx_max-yidx)) / yidx_max;
-            g2_inv = g2_min + (g2_diff * (yidx_max-yidx)) / yidx_max;
-            b2_inv = b2_min + (b2_diff * (yidx_max-yidx)) / yidx_max;
-
-            dest = (char *)bg_data + row*bg_rowbytes;
-            for (i = 0;  i < rpng2_info.width;  ++i) {
-                even_odd_horiz = (int)((i / bgscale) & 1);
-                even_odd = even_odd_vert ^ even_odd_horiz;
-                invert_column =
-                  (even_odd_horiz && (bg[pat].type & 0x10));
-                if (even_odd == 0) {        /* gradient #1 */
-                    if (invert_column) {
-                        *dest++ = r1_inv;
-                        *dest++ = g1_inv;
-                        *dest++ = b1_inv;
-                    } else {
-                        *dest++ = r1;
-                        *dest++ = g1;
-                        *dest++ = b1;
-                    }
-                } else {                    /* gradient #2 */
-                    if ((invert_column && invert_gradient2) ||
-                        (!invert_column && !invert_gradient2))
-                    {
-                        *dest++ = r2;       /* not inverted or */
-                        *dest++ = g2;       /*  doubly inverted */
-                        *dest++ = b2;
-                    } else {
-                        *dest++ = r2_inv;
-                        *dest++ = g2_inv;   /* singly inverted */
-                        *dest++ = b2_inv;
-                    }
-                }
-            }
-        }
-
-/*---------------------------------------------------------------------------
-    Soft gradient-diamonds with scale = bgscale.  Code contributed by Adam
-    M. Costello.
-  ---------------------------------------------------------------------------*/
-
-    } else if ((bg[pat].type & 0x07) == 1) {
-
-        hmax = (bgscale-1)/2;   /* half the max weight of a color */
-        max = 2*hmax;           /* the max weight of a color */
-
-        r1 = rgb[bg[pat].rgb1_max].r;
-        g1 = rgb[bg[pat].rgb1_max].g;
-        b1 = rgb[bg[pat].rgb1_max].b;
-        r2 = rgb[bg[pat].rgb2_max].r;
-        g2 = rgb[bg[pat].rgb2_max].g;
-        b2 = rgb[bg[pat].rgb2_max].b;
-
-        for (row = 0;  row < rpng2_info.height;  ++row) {
-            yidx = (int)(row % bgscale);
-            if (yidx > hmax)
-                yidx = bgscale-1 - yidx;
-            dest = (char *)bg_data + row*bg_rowbytes;
-            for (i = 0;  i < rpng2_info.width;  ++i) {
-                xidx = (int)(i % bgscale);
-                if (xidx > hmax)
-                    xidx = bgscale-1 - xidx;
-                k = xidx + yidx;
-                *dest++ = (k*r1 + (max-k)*r2) / max;
-                *dest++ = (k*g1 + (max-k)*g2) / max;
-                *dest++ = (k*b1 + (max-k)*b2) / max;
-            }
-        }
-
-/*---------------------------------------------------------------------------
-    Radial "starburst" with azimuthal sinusoids; [eventually number of sinu-
-    soids will equal bgscale?].  This one is slow but very cool.  Code con-
-    tributed by Pieter S. van der Meulen (originally in Smalltalk).
-  ---------------------------------------------------------------------------*/
-
-    } else if ((bg[pat].type & 0x07) == 2) {
-        uch ch;
-        int ii, x, y, hw, hh, grayspot;
-        double freq, rotate, saturate, gray, intensity;
-        double angle=0.0, aoffset=0.0, maxDist, dist;
-        double red=0.0, green=0.0, blue=0.0, hue, s, v, f, p, q, t;
-
-        hh = (int)(rpng2_info.height / 2);
-        hw = (int)(rpng2_info.width / 2);
-
-        /* variables for radial waves:
-         *   aoffset:  number of degrees to rotate hue [CURRENTLY NOT USED]
-         *   freq:  number of color beams originating from the center
-         *   grayspot:  size of the graying center area (anti-alias)
-         *   rotate:  rotation of the beams as a function of radius
-         *   saturate:  saturation of beams' shape azimuthally
-         */
-        angle = CLIP(angle, 0.0, 360.0);
-        grayspot = CLIP(bg[pat].bg_gray, 1, (hh + hw));
-        freq = MAX((double)bg[pat].bg_freq, 0.0);
-        saturate = (double)bg[pat].bg_bsat * 0.1;
-        rotate = (double)bg[pat].bg_brot * 0.1;
-        gray = 0.0;
-        intensity = 0.0;
-        maxDist = (double)((hw*hw) + (hh*hh));
-
-        for (row = 0;  row < rpng2_info.height;  ++row) {
-            y = (int)(row - hh);
-            dest = (char *)bg_data + row*bg_rowbytes;
-            for (i = 0;  i < rpng2_info.width;  ++i) {
-                x = (int)(i - hw);
-                angle = (x == 0)? PI_2 : atan((double)y / (double)x);
-                gray = (double)MAX(ABS(y), ABS(x)) / grayspot;
-                gray = MIN(1.0, gray);
-                dist = (double)((x*x) + (y*y)) / maxDist;
-                intensity = cos((angle+(rotate*dist*PI)) * freq) *
-                  gray * saturate;
-                intensity = (MAX(MIN(intensity,1.0),-1.0) + 1.0) * 0.5;
-                hue = (angle + PI) * INV_PI_360 + aoffset;
-                s = gray * ((double)(ABS(x)+ABS(y)) / (double)(hw + hh));
-                s = MIN(MAX(s,0.0), 1.0);
-                v = MIN(MAX(intensity,0.0), 1.0);
-
-                if (s == 0.0) {
-                    ch = (uch)(v * 255.0);
-                    *dest++ = ch;
-                    *dest++ = ch;
-                    *dest++ = ch;
-                } else {
-                    if ((hue < 0.0) || (hue >= 360.0))
-                        hue -= (((int)(hue / 360.0)) * 360.0);
-                    hue /= 60.0;
-                    ii = (int)hue;
-                    f = hue - (double)ii;
-                    p = (1.0 - s) * v;
-                    q = (1.0 - (s * f)) * v;
-                    t = (1.0 - (s * (1.0 - f))) * v;
-                    if      (ii == 0) { red = v; green = t; blue = p; }
-                    else if (ii == 1) { red = q; green = v; blue = p; }
-                    else if (ii == 2) { red = p; green = v; blue = t; }
-                    else if (ii == 3) { red = p; green = q; blue = v; }
-                    else if (ii == 4) { red = t; green = p; blue = v; }
-                    else if (ii == 5) { red = v; green = p; blue = q; }
-                    *dest++ = (uch)(red * 255.0);
-                    *dest++ = (uch)(green * 255.0);
-                    *dest++ = (uch)(blue * 255.0);
-                }
-            }
-        }
-    }
-
-} /* end function rpng2_x_reload_bg_image() */
-
-
-
-
-
-static int is_number(char *p)
-{
-    while (*p) {
-        if (!isdigit(*p))
-            return FALSE;
-        ++p;
-    }
-    return TRUE;
-}
-
-#endif /* FEATURE_LOOP */
-
-
-
-
-
-static void rpng2_x_cleanup(void)
-{
-    if (bg_image && bg_data) {
-        free(bg_data);
-        bg_data = NULL;
-    }
-
-    if (rpng2_info.image_data) {
-        free(rpng2_info.image_data);
-        rpng2_info.image_data = NULL;
-    }
-
-    if (rpng2_info.row_pointers) {
-        free(rpng2_info.row_pointers);
-        rpng2_info.row_pointers = NULL;
-    }
-
-    if (ximage) {
-        if (ximage->data) {
-            free(ximage->data);           /* we allocated it, so we free it */
-            ximage->data = (char *)NULL;  /*  instead of XDestroyImage() */
-        }
-        XDestroyImage(ximage);
-        ximage = NULL;
-    }
-
-    if (have_gc)
-        XFreeGC(display, gc);
-
-    if (have_window)
-        XDestroyWindow(display, window);
-
-    if (have_colormap)
-        XFreeColormap(display, colormap);
-
-    if (have_nondefault_visual)
-        XFree(visual_list);
-}
-
-
-
-
-
-static int rpng2_x_msb(ulg u32val)
-{
-    int i;
-
-    for (i = 31;  i >= 0;  --i) {
-        if (u32val & 0x80000000L)
-            break;
-        u32val <<= 1;
-    }
-    return i;
-}
diff --git a/contrib/gregbook/toucan.png b/contrib/gregbook/toucan.png
deleted file mode 100644
index 03960d4..0000000
--- a/contrib/gregbook/toucan.png
+++ /dev/null
diff --git a/contrib/gregbook/wpng.c b/contrib/gregbook/wpng.c
deleted file mode 100644
index a06e352..0000000
--- a/contrib/gregbook/wpng.c
+++ /dev/null
@@ -1,853 +0,0 @@
-/*---------------------------------------------------------------------------
-
-   wpng - simple PNG-writing program                                 wpng.c
-
-   This program converts certain NetPBM binary files (grayscale and RGB,
-   maxval = 255) to PNG.  Non-interlaced PNGs are written progressively;
-   interlaced PNGs are read and written in one memory-intensive blast.
-
-   Thanks to Jean-loup Gailly for providing the necessary trick to read
-   interactive text from the keyboard while stdin is redirected.  Thanks
-   to Cosmin Truta for Cygwin fixes.
-
-   NOTE:  includes provisional support for PNM type "8" (portable alphamap)
-          images, presumed to be a 32-bit interleaved RGBA format; no pro-
-          vision for possible interleaved grayscale+alpha (16-bit) format.
-          THIS IS UNLIKELY TO BECOME AN OFFICIAL NETPBM ALPHA FORMAT!
-
-   to do:
-    - delete output file if quit before calling any writepng routines
-    - process backspace with -text option under DOS/Win? (currently get ^H)
-
-  ---------------------------------------------------------------------------
-
-   Changelog:
-    - 1.01:  initial public release
-    - 1.02:  modified to allow abbreviated options
-    - 1.03:  removed extraneous character from usage screen; fixed bug in
-              command-line parsing
-    - 1.04:  fixed DOS/OS2/Win32 detection, including partial Cygwin fix
-              (see http://home.att.net/~perlspinr/diffs/GregBook_cygwin.diff)
-    - 2.00:  dual-licensed (added GNU GPL)
-
-        [REPORTED BUG (win32 only):  "contrib/gregbook/wpng.c - cmd line
-         dose not work!  In order to do something useful I needed to redirect
-         both input and output, with cygwin and with bcc32 as well.  Under
-         Linux, the same wpng appears to work fine.  I don't know what is
-         the problem."]
-
-  ---------------------------------------------------------------------------
-
-      Copyright (c) 1998-2007 Greg Roelofs.  All rights reserved.
-
-      This software is provided "as is," without warranty of any kind,
-      express or implied.  In no event shall the author or contributors
-      be held liable for any damages arising in any way from the use of
-      this software.
-
-      The contents of this file are DUAL-LICENSED.  You may modify and/or
-      redistribute this software according to the terms of one of the
-      following two licenses (at your option):
-
-
-      LICENSE 1 ("BSD-like with advertising clause"):
-
-      Permission is granted to anyone to use this software for any purpose,
-      including commercial applications, and to alter it and redistribute
-      it freely, subject to the following restrictions:
-
-      1. Redistributions of source code must retain the above copyright
-         notice, disclaimer, and this list of conditions.
-      2. Redistributions in binary form must reproduce the above copyright
-         notice, disclaimer, and this list of conditions in the documenta-
-         tion and/or other materials provided with the distribution.
-      3. All advertising materials mentioning features or use of this
-         software must display the following acknowledgment:
-
-            This product includes software developed by Greg Roelofs
-            and contributors for the book, "PNG: The Definitive Guide,"
-            published by O'Reilly and Associates.
-
-
-      LICENSE 2 (GNU GPL v2 or later):
-
-      This program is free software; you can redistribute it and/or modify
-      it under the terms of the GNU General Public License as published by
-      the Free Software Foundation; either version 2 of the License, or
-      (at your option) any later version.
-
-      This program is distributed in the hope that it will be useful,
-      but WITHOUT ANY WARRANTY; without even the implied warranty of
-      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-      GNU General Public License for more details.
-
-      You should have received a copy of the GNU General Public License
-      along with this program; if not, write to the Free Software Foundation,
-      Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
-
-  ---------------------------------------------------------------------------*/
-
-#define PROGNAME  "wpng"
-#define VERSION   "2.00 of 2 June 2007"
-#define APPNAME   "Simple PGM/PPM/PAM to PNG Converter"
-
-#if defined(__MSDOS__) || defined(__OS2__)
-#  define DOS_OS2_W32
-#elif defined(WIN32) || defined(_WIN32) || defined(__WIN32__)
-#  ifndef __GNUC__   /* treat Win32 native ports of gcc as Unix environments */
-#    define DOS_OS2_W32
-#  endif
-#endif
-
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <setjmp.h>     /* for jmpbuf declaration in writepng.h */
-#include <time.h>
-
-#ifdef DOS_OS2_W32
-#  include <io.h>       /* for isatty(), setmode() prototypes */
-#  include <fcntl.h>    /* O_BINARY for fdopen() without text translation */
-#  ifdef __EMX__
-#    ifndef getch
-#      define getch() _read_kbd(0, 1, 0)    /* need getche() */
-#    endif
-#  else /* !__EMX__ */
-#    ifdef __GO32__
-#      include <pc.h>
-#      define getch() getkey()  /* GRR:  need getche() */
-#    else
-#      include <conio.h>        /* for getche() console input */
-#    endif
-#  endif /* ?__EMX__ */
-#  define FGETS(buf,len,stream)  dos_kbd_gets(buf,len)
-#else
-#  include <unistd.h>           /* for isatty() prototype */
-#  define FGETS fgets
-#endif
-
-/* #define DEBUG  :  this enables the Trace() macros */
-
-/* #define FORBID_LATIN1_CTRL  :  this requires the user to re-enter any
-   text that includes control characters discouraged by the PNG spec; text
-   that includes an escape character (27) must be re-entered regardless */
-
-#include "writepng.h"   /* typedefs, common macros, writepng prototypes */
-
-
-
-/* local prototypes */
-
-static int  wpng_isvalid_latin1(uch *p, int len);
-static void wpng_cleanup(void);
-
-#ifdef DOS_OS2_W32
-   static char *dos_kbd_gets(char *buf, int len);
-#endif
-
-
-
-static mainprog_info wpng_info;   /* lone global */
-
-
-
-int main(int argc, char **argv)
-{
-#ifndef DOS_OS2_W32
-    FILE *keybd;
-#endif
-#ifdef sgi
-    FILE *tmpfile;      /* or we could just use keybd, since no overlap */
-    char tmpline[80];
-#endif
-    char *inname = NULL, outname[256];
-    char *p, pnmchar, pnmline[256];
-    char *bgstr, *textbuf = NULL;
-    ulg rowbytes;
-    int rc, len = 0;
-    int error = 0;
-    int text = FALSE;
-    int maxval;
-    double LUT_exponent;                /* just the lookup table */
-    double CRT_exponent = 2.2;          /* just the monitor */
-    double default_display_exponent;    /* whole display system */
-    double default_gamma = 0.0;
-
-
-    wpng_info.infile = NULL;
-    wpng_info.outfile = NULL;
-    wpng_info.image_data = NULL;
-    wpng_info.row_pointers = NULL;
-    wpng_info.filter = FALSE;
-    wpng_info.interlaced = FALSE;
-    wpng_info.have_bg = FALSE;
-    wpng_info.have_time = FALSE;
-    wpng_info.have_text = 0;
-    wpng_info.gamma = 0.0;
-
-
-    /* First get the default value for our display-system exponent, i.e.,
-     * the product of the CRT exponent and the exponent corresponding to
-     * the frame-buffer's lookup table (LUT), if any.  If the PNM image
-     * looks correct on the user's display system, its file gamma is the
-     * inverse of this value.  (Note that this is not an exhaustive list
-     * of LUT values--e.g., OpenStep has a lot of weird ones--but it should
-     * cover 99% of the current possibilities.  This section must ensure
-     * that default_display_exponent is positive.) */
-
-#if defined(NeXT)
-    /* third-party utilities can modify the default LUT exponent */
-    LUT_exponent = 1.0 / 2.2;
-    /*
-    if (some_next_function_that_returns_gamma(&next_gamma))
-        LUT_exponent = 1.0 / next_gamma;
-     */
-#elif defined(sgi)
-    LUT_exponent = 1.0 / 1.7;
-    /* there doesn't seem to be any documented function to
-     * get the "gamma" value, so we do it the hard way */
-    tmpfile = fopen("/etc/config/system.glGammaVal", "r");
-    if (tmpfile) {
-        double sgi_gamma;
-
-        fgets(tmpline, 80, tmpfile);
-        fclose(tmpfile);
-        sgi_gamma = atof(tmpline);
-        if (sgi_gamma > 0.0)
-            LUT_exponent = 1.0 / sgi_gamma;
-    }
-#elif defined(Macintosh)
-    LUT_exponent = 1.8 / 2.61;
-    /*
-    if (some_mac_function_that_returns_gamma(&mac_gamma))
-        LUT_exponent = mac_gamma / 2.61;
-     */
-#else
-    LUT_exponent = 1.0;   /* assume no LUT:  most PCs */
-#endif
-
-    /* the defaults above give 1.0, 1.3, 1.5 and 2.2, respectively: */
-    default_display_exponent = LUT_exponent * CRT_exponent;
-
-
-    /* If the user has set the SCREEN_GAMMA environment variable as suggested
-     * (somewhat imprecisely) in the libpng documentation, use that; otherwise
-     * use the default value we just calculated.  Either way, the user may
-     * override this via a command-line option. */
-
-    if ((p = getenv("SCREEN_GAMMA")) != NULL) {
-        double exponent = atof(p);
-
-        if (exponent > 0.0)
-            default_gamma = 1.0 / exponent;
-    }
-
-    if (default_gamma == 0.0)
-        default_gamma = 1.0 / default_display_exponent;
-
-
-    /* Now parse the command line for options and the PNM filename. */
-
-    while (*++argv && !error) {
-        if (!strncmp(*argv, "-i", 2)) {
-            wpng_info.interlaced = TRUE;
-        } else if (!strncmp(*argv, "-time", 3)) {
-            wpng_info.modtime = time(NULL);
-            wpng_info.have_time = TRUE;
-        } else if (!strncmp(*argv, "-text", 3)) {
-            text = TRUE;
-        } else if (!strncmp(*argv, "-gamma", 2)) {
-            if (!*++argv)
-                ++error;
-            else {
-                wpng_info.gamma = atof(*argv);
-                if (wpng_info.gamma <= 0.0)
-                    ++error;
-                else if (wpng_info.gamma > 1.01)
-                    fprintf(stderr, PROGNAME
-                      " warning:  file gammas are usually less than 1.0\n");
-            }
-        } else if (!strncmp(*argv, "-bgcolor", 4)) {
-            if (!*++argv)
-                ++error;
-            else {
-                bgstr = *argv;
-                if (strlen(bgstr) != 7 || bgstr[0] != '#')
-                    ++error;
-                else {
-                    unsigned r, g, b;  /* this way quiets compiler warnings */
-
-                    sscanf(bgstr+1, "%2x%2x%2x", &r, &g, &b);
-                    wpng_info.bg_red   = (uch)r;
-                    wpng_info.bg_green = (uch)g;
-                    wpng_info.bg_blue  = (uch)b;
-                    wpng_info.have_bg = TRUE;
-                }
-            }
-        } else {
-            if (**argv != '-') {
-                inname = *argv;
-                if (argv[1])   /* shouldn't be any more args after filename */
-                    ++error;
-            } else
-                ++error;   /* not expecting any other options */
-        }
-    }
-
-
-    /* open the input and output files, or register an error and abort */
-
-    if (!inname) {
-        if (isatty(0)) {
-            fprintf(stderr, PROGNAME
-              ":  must give input filename or provide image data via stdin\n");
-            ++error;
-        } else {
-#ifdef DOS_OS2_W32
-            /* some buggy C libraries require BOTH setmode() and fdopen(bin) */
-            setmode(fileno(stdin), O_BINARY);
-            setmode(fileno(stdout), O_BINARY);
-#endif
-            if ((wpng_info.infile = fdopen(fileno(stdin), "rb")) == NULL) {
-                fprintf(stderr, PROGNAME
-                  ":  unable to reopen stdin in binary mode\n");
-                ++error;
-            } else
-            if ((wpng_info.outfile = fdopen(fileno(stdout), "wb")) == NULL) {
-                fprintf(stderr, PROGNAME
-                  ":  unable to reopen stdout in binary mode\n");
-                fclose(wpng_info.infile);
-                ++error;
-            } else
-                wpng_info.filter = TRUE;
-        }
-    } else if ((len = strlen(inname)) > 250) {
-        fprintf(stderr, PROGNAME ":  input filename is too long [%d chars]\n",
-          len);
-        ++error;
-    } else if (!(wpng_info.infile = fopen(inname, "rb"))) {
-        fprintf(stderr, PROGNAME ":  can't open input file [%s]\n", inname);
-        ++error;
-    }
-
-    if (!error) {
-        fgets(pnmline, 256, wpng_info.infile);
-        if (pnmline[0] != 'P' || ((pnmchar = pnmline[1]) != '5' &&
-            pnmchar != '6' && pnmchar != '8'))
-        {
-            fprintf(stderr, PROGNAME
-              ":  input file [%s] is not a binary PGM, PPM or PAM file\n",
-              inname);
-            ++error;
-        } else {
-            wpng_info.pnmtype = (int)(pnmchar - '0');
-            if (wpng_info.pnmtype != 8)
-                wpng_info.have_bg = FALSE;  /* no need for bg if opaque */
-            do {
-                fgets(pnmline, 256, wpng_info.infile);  /* lose any comments */
-            } while (pnmline[0] == '#');
-            sscanf(pnmline, "%ld %ld", &wpng_info.width, &wpng_info.height);
-            do {
-                fgets(pnmline, 256, wpng_info.infile);  /* more comment lines */
-            } while (pnmline[0] == '#');
-            sscanf(pnmline, "%d", &maxval);
-            if (wpng_info.width <= 0L || wpng_info.height <= 0L ||
-                maxval != 255)
-            {
-                fprintf(stderr, PROGNAME
-                  ":  only positive width/height, maxval == 255 allowed \n");
-                ++error;
-            }
-            wpng_info.sample_depth = 8;  /* <==> maxval 255 */
-
-            if (!wpng_info.filter) {
-                /* make outname from inname */
-                if ((p = strrchr(inname, '.')) == NULL ||
-                    (p - inname) != (len - 4))
-                {
-                    strcpy(outname, inname);
-                    strcpy(outname+len, ".png");
-                } else {
-                    len -= 4;
-                    strncpy(outname, inname, len);
-                    strcpy(outname+len, ".png");
-                }
-                /* check if outname already exists; if not, open */
-                if ((wpng_info.outfile = fopen(outname, "rb")) != NULL) {
-                    fprintf(stderr, PROGNAME ":  output file exists [%s]\n",
-                      outname);
-                    fclose(wpng_info.outfile);
-                    ++error;
-                } else if (!(wpng_info.outfile = fopen(outname, "wb"))) {
-                    fprintf(stderr, PROGNAME ":  can't open output file [%s]\n",
-                      outname);
-                    ++error;
-                }
-            }
-        }
-        if (error) {
-            fclose(wpng_info.infile);
-            wpng_info.infile = NULL;
-            if (wpng_info.filter) {
-                fclose(wpng_info.outfile);
-                wpng_info.outfile = NULL;
-            }
-        }
-    }
-
-
-    /* if we had any errors, print usage and die horrible death...arrr! */
-
-    if (error) {
-        fprintf(stderr, "\n%s %s:  %s\n", PROGNAME, VERSION, APPNAME);
-        writepng_version_info();
-        fprintf(stderr, "\n"
-"Usage:  %s [-gamma exp] [-bgcolor bg] [-text] [-time] [-interlace] pnmfile\n"
-"or: ... | %s [-gamma exp] [-bgcolor bg] [-text] [-time] [-interlace] | ...\n"
-         "    exp \ttransfer-function exponent (``gamma'') of the image in\n"
-         "\t\t  floating-point format (e.g., ``%.5f''); if image looks\n"
-         "\t\t  correct on given display system, image gamma is equal to\n"
-         "\t\t  inverse of display-system exponent, i.e., 1 / (LUT * CRT)\n"
-         "\t\t  (where LUT = lookup-table exponent and CRT = CRT exponent;\n"
-         "\t\t  first varies, second is usually 2.2, all are positive)\n"
-         "    bg  \tdesired background color for alpha-channel images, in\n"
-         "\t\t  7-character hex RGB format (e.g., ``#ff7700'' for orange:\n"
-         "\t\t  same as HTML colors)\n"
-         "    -text\tprompt interactively for text info (tEXt chunks)\n"
-         "    -time\tinclude a tIME chunk (last modification time)\n"
-         "    -interlace\twrite interlaced PNG image\n"
-         "\n"
-"pnmfile or stdin must be a binary PGM (`P5'), PPM (`P6') or (extremely\n"
-"unofficial and unsupported!) PAM (`P8') file.  Currently it is required\n"
-"to have maxval == 255 (i.e., no scaling).  If pnmfile is specified, it\n"
-"is converted to the corresponding PNG file with the same base name but a\n"
-"``.png'' extension; files read from stdin are converted and sent to stdout.\n"
-"The conversion is progressive (low memory usage) unless interlacing is\n"
-"requested; in that case the whole image will be buffered in memory and\n"
-"written in one call.\n"
-         "\n", PROGNAME, PROGNAME, default_gamma);
-        exit(1);
-    }
-
-
-    /* prepare the text buffers for libpng's use; note that even though
-     * PNG's png_text struct includes a length field, we don't have to fill
-     * it out */
-
-    if (text &&
-#ifndef DOS_OS2_W32
-        (keybd = fdopen(fileno(stderr), "r")) != NULL &&
-#endif
-        (textbuf = (char *)malloc((5 + 9)*75)) != NULL)
-    {
-        int i, valid, result;
-
-        fprintf(stderr,
-          "Enter text info (no more than 72 characters per line);\n");
-        fprintf(stderr, "to skip a field, hit the <Enter> key.\n");
-        /* note:  just <Enter> leaves len == 1 */
-
-        do {
-            valid = TRUE;
-            p = textbuf + TEXT_TITLE_OFFSET;
-            fprintf(stderr, "  Title: ");
-            fflush(stderr);
-            if (FGETS(p, 74, keybd) && (len = strlen(p)) > 1) {
-                if (p[len-1] == '\n')
-                    p[--len] = '\0';
-                wpng_info.title = p;
-                wpng_info.have_text |= TEXT_TITLE;
-                if ((result = wpng_isvalid_latin1((uch *)p, len)) >= 0) {
-                    fprintf(stderr, "    " PROGNAME " warning:  character code"
-                      " %u is %sdiscouraged by the PNG\n    specification "
-                      "[first occurrence was at character position #%d]\n",
-                      (unsigned)p[result], (p[result] == 27)? "strongly " : "",
-                      result+1);
-                    fflush(stderr);
-#ifdef FORBID_LATIN1_CTRL
-                    wpng_info.have_text &= ~TEXT_TITLE;
-                    valid = FALSE;
-#else
-                    if (p[result] == 27) {    /* escape character */
-                        wpng_info.have_text &= ~TEXT_TITLE;
-                        valid = FALSE;
-                    }
-#endif
-                }
-            }
-        } while (!valid);
-
-        do {
-            valid = TRUE;
-            p = textbuf + TEXT_AUTHOR_OFFSET;
-            fprintf(stderr, "  Author: ");
-            fflush(stderr);
-            if (FGETS(p, 74, keybd) && (len = strlen(p)) > 1) {
-                if (p[len-1] == '\n')
-                    p[--len] = '\0';
-                wpng_info.author = p;
-                wpng_info.have_text |= TEXT_AUTHOR;
-                if ((result = wpng_isvalid_latin1((uch *)p, len)) >= 0) {
-                    fprintf(stderr, "    " PROGNAME " warning:  character code"
-                      " %u is %sdiscouraged by the PNG\n    specification "
-                      "[first occurrence was at character position #%d]\n",
-                      (unsigned)p[result], (p[result] == 27)? "strongly " : "",
-                      result+1);
-                    fflush(stderr);
-#ifdef FORBID_LATIN1_CTRL
-                    wpng_info.have_text &= ~TEXT_AUTHOR;
-                    valid = FALSE;
-#else
-                    if (p[result] == 27) {    /* escape character */
-                        wpng_info.have_text &= ~TEXT_AUTHOR;
-                        valid = FALSE;
-                    }
-#endif
-                }
-            }
-        } while (!valid);
-
-        do {
-            valid = TRUE;
-            p = textbuf + TEXT_DESC_OFFSET;
-            fprintf(stderr, "  Description (up to 9 lines):\n");
-            for (i = 1;  i < 10;  ++i) {
-                fprintf(stderr, "    [%d] ", i);
-                fflush(stderr);
-                if (FGETS(p, 74, keybd) && (len = strlen(p)) > 1)
-                    p += len;   /* now points at NULL; char before is newline */
-                else
-                    break;
-            }
-            if ((len = p - (textbuf + TEXT_DESC_OFFSET)) > 1) {
-                if (p[-1] == '\n') {
-                    p[-1] = '\0';
-                    --len;
-                }
-                wpng_info.desc = textbuf + TEXT_DESC_OFFSET;
-                wpng_info.have_text |= TEXT_DESC;
-                p = textbuf + TEXT_DESC_OFFSET;
-                if ((result = wpng_isvalid_latin1((uch *)p, len)) >= 0) {
-                    fprintf(stderr, "    " PROGNAME " warning:  character code"
-                      " %u is %sdiscouraged by the PNG\n    specification "
-                      "[first occurrence was at character position #%d]\n",
-                      (unsigned)p[result], (p[result] == 27)? "strongly " : "",
-                      result+1);
-                    fflush(stderr);
-#ifdef FORBID_LATIN1_CTRL
-                    wpng_info.have_text &= ~TEXT_DESC;
-                    valid = FALSE;
-#else
-                    if (p[result] == 27) {    /* escape character */
-                        wpng_info.have_text &= ~TEXT_DESC;
-                        valid = FALSE;
-                    }
-#endif
-                }
-            }
-        } while (!valid);
-
-        do {
-            valid = TRUE;
-            p = textbuf + TEXT_COPY_OFFSET;
-            fprintf(stderr, "  Copyright: ");
-            fflush(stderr);
-            if (FGETS(p, 74, keybd) && (len = strlen(p)) > 1) {
-                if (p[len-1] == '\n')
-                    p[--len] = '\0';
-                wpng_info.copyright = p;
-                wpng_info.have_text |= TEXT_COPY;
-                if ((result = wpng_isvalid_latin1((uch *)p, len)) >= 0) {
-                    fprintf(stderr, "    " PROGNAME " warning:  character code"
-                      " %u is %sdiscouraged by the PNG\n    specification "
-                      "[first occurrence was at character position #%d]\n",
-                      (unsigned)p[result], (p[result] == 27)? "strongly " : "",
-                      result+1);
-                    fflush(stderr);
-#ifdef FORBID_LATIN1_CTRL
-                    wpng_info.have_text &= ~TEXT_COPY;
-                    valid = FALSE;
-#else
-                    if (p[result] == 27) {    /* escape character */
-                        wpng_info.have_text &= ~TEXT_COPY;
-                        valid = FALSE;
-                    }
-#endif
-                }
-            }
-        } while (!valid);
-
-        do {
-            valid = TRUE;
-            p = textbuf + TEXT_EMAIL_OFFSET;
-            fprintf(stderr, "  E-mail: ");
-            fflush(stderr);
-            if (FGETS(p, 74, keybd) && (len = strlen(p)) > 1) {
-                if (p[len-1] == '\n')
-                    p[--len] = '\0';
-                wpng_info.email = p;
-                wpng_info.have_text |= TEXT_EMAIL;
-                if ((result = wpng_isvalid_latin1((uch *)p, len)) >= 0) {
-                    fprintf(stderr, "    " PROGNAME " warning:  character code"
-                      " %u is %sdiscouraged by the PNG\n    specification "
-                      "[first occurrence was at character position #%d]\n",
-                      (unsigned)p[result], (p[result] == 27)? "strongly " : "",
-                      result+1);
-                    fflush(stderr);
-#ifdef FORBID_LATIN1_CTRL
-                    wpng_info.have_text &= ~TEXT_EMAIL;
-                    valid = FALSE;
-#else
-                    if (p[result] == 27) {    /* escape character */
-                        wpng_info.have_text &= ~TEXT_EMAIL;
-                        valid = FALSE;
-                    }
-#endif
-                }
-            }
-        } while (!valid);
-
-        do {
-            valid = TRUE;
-            p = textbuf + TEXT_URL_OFFSET;
-            fprintf(stderr, "  URL: ");
-            fflush(stderr);
-            if (FGETS(p, 74, keybd) && (len = strlen(p)) > 1) {
-                if (p[len-1] == '\n')
-                    p[--len] = '\0';
-                wpng_info.url = p;
-                wpng_info.have_text |= TEXT_URL;
-                if ((result = wpng_isvalid_latin1((uch *)p, len)) >= 0) {
-                    fprintf(stderr, "    " PROGNAME " warning:  character code"
-                      " %u is %sdiscouraged by the PNG\n    specification "
-                      "[first occurrence was at character position #%d]\n",
-                      (unsigned)p[result], (p[result] == 27)? "strongly " : "",
-                      result+1);
-                    fflush(stderr);
-#ifdef FORBID_LATIN1_CTRL
-                    wpng_info.have_text &= ~TEXT_URL;
-                    valid = FALSE;
-#else
-                    if (p[result] == 27) {    /* escape character */
-                        wpng_info.have_text &= ~TEXT_URL;
-                        valid = FALSE;
-                    }
-#endif
-                }
-            }
-        } while (!valid);
-
-#ifndef DOS_OS2_W32
-        fclose(keybd);
-#endif
-
-    } else if (text) {
-        fprintf(stderr, PROGNAME ":  unable to allocate memory for text\n");
-        text = FALSE;
-        wpng_info.have_text = 0;
-    }
-
-
-    /* allocate libpng stuff, initialize transformations, write pre-IDAT data */
-
-    if ((rc = writepng_init(&wpng_info)) != 0) {
-        switch (rc) {
-            case 2:
-                fprintf(stderr, PROGNAME
-                  ":  libpng initialization problem (longjmp)\n");
-                break;
-            case 4:
-                fprintf(stderr, PROGNAME ":  insufficient memory\n");
-                break;
-            case 11:
-                fprintf(stderr, PROGNAME
-                  ":  internal logic error (unexpected PNM type)\n");
-                break;
-            default:
-                fprintf(stderr, PROGNAME
-                  ":  unknown writepng_init() error\n");
-                break;
-        }
-        exit(rc);
-    }
-
-
-    /* free textbuf, since it's a completely local variable and all text info
-     * has just been written to the PNG file */
-
-    if (text && textbuf) {
-        free(textbuf);
-        textbuf = NULL;
-    }
-
-
-    /* calculate rowbytes on basis of image type; note that this becomes much
-     * more complicated if we choose to support PBM type, ASCII PNM types, or
-     * 16-bit-per-sample binary data [currently not an official NetPBM type] */
-
-    if (wpng_info.pnmtype == 5)
-        rowbytes = wpng_info.width;
-    else if (wpng_info.pnmtype == 6)
-        rowbytes = wpng_info.width * 3;
-    else /* if (wpng_info.pnmtype == 8) */
-        rowbytes = wpng_info.width * 4;
-
-
-    /* read and write the image, either in its entirety (if writing interlaced
-     * PNG) or row by row (if non-interlaced) */
-
-    fprintf(stderr, "Encoding image data...\n");
-    fflush(stderr);
-
-    if (wpng_info.interlaced) {
-        long i;
-        ulg bytes;
-        ulg image_bytes = rowbytes * wpng_info.height;   /* overflow? */
-
-        wpng_info.image_data = (uch *)malloc(image_bytes);
-        wpng_info.row_pointers = (uch **)malloc(wpng_info.height*sizeof(uch *));
-        if (wpng_info.image_data == NULL || wpng_info.row_pointers == NULL) {
-            fprintf(stderr, PROGNAME ":  insufficient memory for image data\n");
-            writepng_cleanup(&wpng_info);
-            wpng_cleanup();
-            exit(5);
-        }
-        for (i = 0;  i < wpng_info.height;  ++i)
-            wpng_info.row_pointers[i] = wpng_info.image_data + i*rowbytes;
-        bytes = fread(wpng_info.image_data, 1, image_bytes, wpng_info.infile);
-        if (bytes != image_bytes) {
-            fprintf(stderr, PROGNAME ":  expected %lu bytes, got %lu bytes\n",
-              image_bytes, bytes);
-            fprintf(stderr, "  (continuing anyway)\n");
-        }
-        if (writepng_encode_image(&wpng_info) != 0) {
-            fprintf(stderr, PROGNAME
-              ":  libpng problem (longjmp) while writing image data\n");
-            writepng_cleanup(&wpng_info);
-            wpng_cleanup();
-            exit(2);
-        }
-
-    } else /* not interlaced:  write progressively (row by row) */ {
-        long j;
-        ulg bytes;
-
-        wpng_info.image_data = (uch *)malloc(rowbytes);
-        if (wpng_info.image_data == NULL) {
-            fprintf(stderr, PROGNAME ":  insufficient memory for row data\n");
-            writepng_cleanup(&wpng_info);
-            wpng_cleanup();
-            exit(5);
-        }
-        error = 0;
-        for (j = wpng_info.height;  j > 0L;  --j) {
-            bytes = fread(wpng_info.image_data, 1, rowbytes, wpng_info.infile);
-            if (bytes != rowbytes) {
-                fprintf(stderr, PROGNAME
-                  ":  expected %lu bytes, got %lu bytes (row %ld)\n", rowbytes,
-                  bytes, wpng_info.height-j);
-                ++error;
-                break;
-            }
-            if (writepng_encode_row(&wpng_info) != 0) {
-                fprintf(stderr, PROGNAME
-                  ":  libpng problem (longjmp) while writing row %ld\n",
-                  wpng_info.height-j);
-                ++error;
-                break;
-            }
-        }
-        if (error) {
-            writepng_cleanup(&wpng_info);
-            wpng_cleanup();
-            exit(2);
-        }
-        if (writepng_encode_finish(&wpng_info) != 0) {
-            fprintf(stderr, PROGNAME ":  error on final libpng call\n");
-            writepng_cleanup(&wpng_info);
-            wpng_cleanup();
-            exit(2);
-        }
-    }
-
-
-    /* OK, we're done (successfully):  clean up all resources and quit */
-
-    fprintf(stderr, "Done.\n");
-    fflush(stderr);
-
-    writepng_cleanup(&wpng_info);
-    wpng_cleanup();
-
-    return 0;
-}
-
-
-
-
-
-static int wpng_isvalid_latin1(uch *p, int len)
-{
-    int i, result = -1;
-
-    for (i = 0;  i < len;  ++i) {
-        if (p[i] == 10 || (p[i] > 31 && p[i] < 127) || p[i] > 160)
-            continue;           /* character is completely OK */
-        if (result < 0 || (p[result] != 27 && p[i] == 27))
-            result = i;         /* mark location of first questionable one */
-    }                           /*  or of first escape character (bad) */
-
-    return result;
-}
-
-
-
-
-
-static void wpng_cleanup(void)
-{
-    if (wpng_info.outfile) {
-        fclose(wpng_info.outfile);
-        wpng_info.outfile = NULL;
-    }
-
-    if (wpng_info.infile) {
-        fclose(wpng_info.infile);
-        wpng_info.infile = NULL;
-    }
-
-    if (wpng_info.image_data) {
-        free(wpng_info.image_data);
-        wpng_info.image_data = NULL;
-    }
-
-    if (wpng_info.row_pointers) {
-        free(wpng_info.row_pointers);
-        wpng_info.row_pointers = NULL;
-    }
-}
-
-
-
-
-#ifdef DOS_OS2_W32
-
-static char *dos_kbd_gets(char *buf, int len)
-{
-    int ch, count=0;
-
-    do {
-        buf[count++] = ch = getche();
-    } while (ch != '\r' && count < len-1);
-
-    buf[count--] = '\0';        /* terminate string */
-    if (buf[count] == '\r')     /* Enter key makes CR, so change to newline */
-        buf[count] = '\n';
-
-    fprintf(stderr, "\n");      /* Enter key does *not* cause a newline */
-    fflush(stderr);
-
-    return buf;
-}
-
-#endif /* DOS_OS2_W32 */
diff --git a/contrib/gregbook/writepng.c b/contrib/gregbook/writepng.c
deleted file mode 100644
index e6d81ea..0000000
--- a/contrib/gregbook/writepng.c
+++ /dev/null
@@ -1,392 +0,0 @@
-/*---------------------------------------------------------------------------
-
-   wpng - simple PNG-writing program                             writepng.c
-
-  ---------------------------------------------------------------------------
-
-      Copyright (c) 1998-2007 Greg Roelofs.  All rights reserved.
-
-      This software is provided "as is," without warranty of any kind,
-      express or implied.  In no event shall the author or contributors
-      be held liable for any damages arising in any way from the use of
-      this software.
-
-      The contents of this file are DUAL-LICENSED.  You may modify and/or
-      redistribute this software according to the terms of one of the
-      following two licenses (at your option):
-
-
-      LICENSE 1 ("BSD-like with advertising clause"):
-
-      Permission is granted to anyone to use this software for any purpose,
-      including commercial applications, and to alter it and redistribute
-      it freely, subject to the following restrictions:
-
-      1. Redistributions of source code must retain the above copyright
-         notice, disclaimer, and this list of conditions.
-      2. Redistributions in binary form must reproduce the above copyright
-         notice, disclaimer, and this list of conditions in the documenta-
-         tion and/or other materials provided with the distribution.
-      3. All advertising materials mentioning features or use of this
-         software must display the following acknowledgment:
-
-            This product includes software developed by Greg Roelofs
-            and contributors for the book, "PNG: The Definitive Guide,"
-            published by O'Reilly and Associates.
-
-
-      LICENSE 2 (GNU GPL v2 or later):
-
-      This program is free software; you can redistribute it and/or modify
-      it under the terms of the GNU General Public License as published by
-      the Free Software Foundation; either version 2 of the License, or
-      (at your option) any later version.
-
-      This program is distributed in the hope that it will be useful,
-      but WITHOUT ANY WARRANTY; without even the implied warranty of
-      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-      GNU General Public License for more details.
-
-      You should have received a copy of the GNU General Public License
-      along with this program; if not, write to the Free Software Foundation,
-      Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
-
-  ---------------------------------------------------------------------------*/
-
-
-#include <stdlib.h>     /* for exit() prototype */
-
-#include "png.h"        /* libpng header; includes zlib.h and setjmp.h */
-#include "writepng.h"   /* typedefs, common macros, public prototypes */
-
-
-/* local prototype */
-
-static void writepng_error_handler(png_structp png_ptr, png_const_charp msg);
-
-
-
-void writepng_version_info(void)
-{
-  fprintf(stderr, "   Compiled with libpng %s; using libpng %s.\n",
-    PNG_LIBPNG_VER_STRING, png_libpng_ver);
-  fprintf(stderr, "   Compiled with zlib %s; using zlib %s.\n",
-    ZLIB_VERSION, zlib_version);
-}
-
-
-
-
-/* returns 0 for success, 2 for libpng problem, 4 for out of memory, 11 for
- *  unexpected pnmtype; note that outfile might be stdout */
-
-int writepng_init(mainprog_info *mainprog_ptr)
-{
-    png_structp  png_ptr;       /* note:  temporary variables! */
-    png_infop  info_ptr;
-    int color_type, interlace_type;
-
-
-    /* could also replace libpng warning-handler (final NULL), but no need: */
-
-    png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, mainprog_ptr,
-      writepng_error_handler, NULL);
-    if (!png_ptr)
-        return 4;   /* out of memory */
-
-    info_ptr = png_create_info_struct(png_ptr);
-    if (!info_ptr) {
-        png_destroy_write_struct(&png_ptr, NULL);
-        return 4;   /* out of memory */
-    }
-
-
-    /* setjmp() must be called in every function that calls a PNG-writing
-     * libpng function, unless an alternate error handler was installed--
-     * but compatible error handlers must either use longjmp() themselves
-     * (as in this program) or exit immediately, so here we go: */
-
-    if (setjmp(mainprog_ptr->jmpbuf)) {
-        png_destroy_write_struct(&png_ptr, &info_ptr);
-        return 2;
-    }
-
-
-    /* make sure outfile is (re)opened in BINARY mode */
-
-    png_init_io(png_ptr, mainprog_ptr->outfile);
-
-
-    /* set the compression levels--in general, always want to leave filtering
-     * turned on (except for palette images) and allow all of the filters,
-     * which is the default; want 32K zlib window, unless entire image buffer
-     * is 16K or smaller (unknown here)--also the default; usually want max
-     * compression (NOT the default); and remaining compression flags should
-     * be left alone */
-
-    png_set_compression_level(png_ptr, Z_BEST_COMPRESSION);
-/*
-    >> this is default for no filtering; Z_FILTERED is default otherwise:
-    png_set_compression_strategy(png_ptr, Z_DEFAULT_STRATEGY);
-    >> these are all defaults:
-    png_set_compression_mem_level(png_ptr, 8);
-    png_set_compression_window_bits(png_ptr, 15);
-    png_set_compression_method(png_ptr, 8);
- */
-
-
-    /* set the image parameters appropriately */
-
-    if (mainprog_ptr->pnmtype == 5)
-        color_type = PNG_COLOR_TYPE_GRAY;
-    else if (mainprog_ptr->pnmtype == 6)
-        color_type = PNG_COLOR_TYPE_RGB;
-    else if (mainprog_ptr->pnmtype == 8)
-        color_type = PNG_COLOR_TYPE_RGB_ALPHA;
-    else {
-        png_destroy_write_struct(&png_ptr, &info_ptr);
-        return 11;
-    }
-
-    interlace_type = mainprog_ptr->interlaced? PNG_INTERLACE_ADAM7 :
-                                               PNG_INTERLACE_NONE;
-
-    png_set_IHDR(png_ptr, info_ptr, mainprog_ptr->width, mainprog_ptr->height,
-      mainprog_ptr->sample_depth, color_type, interlace_type,
-      PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
-
-    if (mainprog_ptr->gamma > 0.0)
-        png_set_gAMA(png_ptr, info_ptr, mainprog_ptr->gamma);
-
-    if (mainprog_ptr->have_bg) {   /* we know it's RGBA, not gray+alpha */
-        png_color_16  background;
-
-        background.red = mainprog_ptr->bg_red;
-        background.green = mainprog_ptr->bg_green;
-        background.blue = mainprog_ptr->bg_blue;
-        png_set_bKGD(png_ptr, info_ptr, &background);
-    }
-
-    if (mainprog_ptr->have_time) {
-        png_time  modtime;
-
-        png_convert_from_time_t(&modtime, mainprog_ptr->modtime);
-        png_set_tIME(png_ptr, info_ptr, &modtime);
-    }
-
-    if (mainprog_ptr->have_text) {
-        png_text  text[6];
-        int  num_text = 0;
-
-        if (mainprog_ptr->have_text & TEXT_TITLE) {
-            text[num_text].compression = PNG_TEXT_COMPRESSION_NONE;
-            text[num_text].key = "Title";
-            text[num_text].text = mainprog_ptr->title;
-            ++num_text;
-        }
-        if (mainprog_ptr->have_text & TEXT_AUTHOR) {
-            text[num_text].compression = PNG_TEXT_COMPRESSION_NONE;
-            text[num_text].key = "Author";
-            text[num_text].text = mainprog_ptr->author;
-            ++num_text;
-        }
-        if (mainprog_ptr->have_text & TEXT_DESC) {
-            text[num_text].compression = PNG_TEXT_COMPRESSION_NONE;
-            text[num_text].key = "Description";
-            text[num_text].text = mainprog_ptr->desc;
-            ++num_text;
-        }
-        if (mainprog_ptr->have_text & TEXT_COPY) {
-            text[num_text].compression = PNG_TEXT_COMPRESSION_NONE;
-            text[num_text].key = "Copyright";
-            text[num_text].text = mainprog_ptr->copyright;
-            ++num_text;
-        }
-        if (mainprog_ptr->have_text & TEXT_EMAIL) {
-            text[num_text].compression = PNG_TEXT_COMPRESSION_NONE;
-            text[num_text].key = "E-mail";
-            text[num_text].text = mainprog_ptr->email;
-            ++num_text;
-        }
-        if (mainprog_ptr->have_text & TEXT_URL) {
-            text[num_text].compression = PNG_TEXT_COMPRESSION_NONE;
-            text[num_text].key = "URL";
-            text[num_text].text = mainprog_ptr->url;
-            ++num_text;
-        }
-        png_set_text(png_ptr, info_ptr, text, num_text);
-    }
-
-
-    /* write all chunks up to (but not including) first IDAT */
-
-    png_write_info(png_ptr, info_ptr);
-
-
-    /* if we wanted to write any more text info *after* the image data, we
-     * would set up text struct(s) here and call png_set_text() again, with
-     * just the new data; png_set_tIME() could also go here, but it would
-     * have no effect since we already called it above (only one tIME chunk
-     * allowed) */
-
-
-    /* set up the transformations:  for now, just pack low-bit-depth pixels
-     * into bytes (one, two or four pixels per byte) */
-
-    png_set_packing(png_ptr);
-/*  png_set_shift(png_ptr, &sig_bit);  to scale low-bit-depth values */
-
-
-    /* make sure we save our pointers for use in writepng_encode_image() */
-
-    mainprog_ptr->png_ptr = png_ptr;
-    mainprog_ptr->info_ptr = info_ptr;
-
-
-    /* OK, that's all we need to do for now; return happy */
-
-    return 0;
-}
-
-
-
-
-
-/* returns 0 for success, 2 for libpng (longjmp) problem */
-
-int writepng_encode_image(mainprog_info *mainprog_ptr)
-{
-    png_structp png_ptr = (png_structp)mainprog_ptr->png_ptr;
-    png_infop info_ptr = (png_infop)mainprog_ptr->info_ptr;
-
-
-    /* as always, setjmp() must be called in every function that calls a
-     * PNG-writing libpng function */
-
-    if (setjmp(mainprog_ptr->jmpbuf)) {
-        png_destroy_write_struct(&png_ptr, &info_ptr);
-        mainprog_ptr->png_ptr = NULL;
-        mainprog_ptr->info_ptr = NULL;
-        return 2;
-    }
-
-
-    /* and now we just write the whole image; libpng takes care of interlacing
-     * for us */
-
-    png_write_image(png_ptr, mainprog_ptr->row_pointers);
-
-
-    /* since that's it, we also close out the end of the PNG file now--if we
-     * had any text or time info to write after the IDATs, second argument
-     * would be info_ptr, but we optimize slightly by sending NULL pointer: */
-
-    png_write_end(png_ptr, NULL);
-
-    return 0;
-}
-
-
-
-
-
-/* returns 0 if succeeds, 2 if libpng problem */
-
-int writepng_encode_row(mainprog_info *mainprog_ptr)  /* NON-interlaced only! */
-{
-    png_structp png_ptr = (png_structp)mainprog_ptr->png_ptr;
-    png_infop info_ptr = (png_infop)mainprog_ptr->info_ptr;
-
-
-    /* as always, setjmp() must be called in every function that calls a
-     * PNG-writing libpng function */
-
-    if (setjmp(mainprog_ptr->jmpbuf)) {
-        png_destroy_write_struct(&png_ptr, &info_ptr);
-        mainprog_ptr->png_ptr = NULL;
-        mainprog_ptr->info_ptr = NULL;
-        return 2;
-    }
-
-
-    /* image_data points at our one row of image data */
-
-    png_write_row(png_ptr, mainprog_ptr->image_data);
-
-    return 0;
-}
-
-
-
-
-
-/* returns 0 if succeeds, 2 if libpng problem */
-
-int writepng_encode_finish(mainprog_info *mainprog_ptr)   /* NON-interlaced! */
-{
-    png_structp png_ptr = (png_structp)mainprog_ptr->png_ptr;
-    png_infop info_ptr = (png_infop)mainprog_ptr->info_ptr;
-
-
-    /* as always, setjmp() must be called in every function that calls a
-     * PNG-writing libpng function */
-
-    if (setjmp(mainprog_ptr->jmpbuf)) {
-        png_destroy_write_struct(&png_ptr, &info_ptr);
-        mainprog_ptr->png_ptr = NULL;
-        mainprog_ptr->info_ptr = NULL;
-        return 2;
-    }
-
-
-    /* close out PNG file; if we had any text or time info to write after
-     * the IDATs, second argument would be info_ptr: */
-
-    png_write_end(png_ptr, NULL);
-
-    return 0;
-}
-
-
-
-
-
-void writepng_cleanup(mainprog_info *mainprog_ptr)
-{
-    png_structp png_ptr = (png_structp)mainprog_ptr->png_ptr;
-    png_infop info_ptr = (png_infop)mainprog_ptr->info_ptr;
-
-    if (png_ptr && info_ptr)
-        png_destroy_write_struct(&png_ptr, &info_ptr);
-}
-
-
-
-
-
-static void writepng_error_handler(png_structp png_ptr, png_const_charp msg)
-{
-    mainprog_info  *mainprog_ptr;
-
-    /* This function, aside from the extra step of retrieving the "error
-     * pointer" (below) and the fact that it exists within the application
-     * rather than within libpng, is essentially identical to libpng's
-     * default error handler.  The second point is critical:  since both
-     * setjmp() and longjmp() are called from the same code, they are
-     * guaranteed to have compatible notions of how big a jmp_buf is,
-     * regardless of whether _BSD_SOURCE or anything else has (or has not)
-     * been defined. */
-
-    fprintf(stderr, "writepng libpng error: %s\n", msg);
-    fflush(stderr);
-
-    mainprog_ptr = png_get_error_ptr(png_ptr);
-    if (mainprog_ptr == NULL) {         /* we are completely hosed now */
-        fprintf(stderr,
-          "writepng severe error:  jmpbuf not recoverable; terminating.\n");
-        fflush(stderr);
-        exit(99);
-    }
-
-    longjmp(mainprog_ptr->jmpbuf, 1);
-}
diff --git a/contrib/gregbook/writepng.h b/contrib/gregbook/writepng.h
deleted file mode 100644
index 78b966b..0000000
--- a/contrib/gregbook/writepng.h
+++ /dev/null
@@ -1,133 +0,0 @@
-/*---------------------------------------------------------------------------
-
-   wpng - simple PNG-writing program                             writepng.h
-
-  ---------------------------------------------------------------------------
-
-      Copyright (c) 1998-2007 Greg Roelofs.  All rights reserved.
-
-      This software is provided "as is," without warranty of any kind,
-      express or implied.  In no event shall the author or contributors
-      be held liable for any damages arising in any way from the use of
-      this software.
-
-      The contents of this file are DUAL-LICENSED.  You may modify and/or
-      redistribute this software according to the terms of one of the
-      following two licenses (at your option):
-
-
-      LICENSE 1 ("BSD-like with advertising clause"):
-
-      Permission is granted to anyone to use this software for any purpose,
-      including commercial applications, and to alter it and redistribute
-      it freely, subject to the following restrictions:
-
-      1. Redistributions of source code must retain the above copyright
-         notice, disclaimer, and this list of conditions.
-      2. Redistributions in binary form must reproduce the above copyright
-         notice, disclaimer, and this list of conditions in the documenta-
-         tion and/or other materials provided with the distribution.
-      3. All advertising materials mentioning features or use of this
-         software must display the following acknowledgment:
-
-            This product includes software developed by Greg Roelofs
-            and contributors for the book, "PNG: The Definitive Guide,"
-            published by O'Reilly and Associates.
-
-
-      LICENSE 2 (GNU GPL v2 or later):
-
-      This program is free software; you can redistribute it and/or modify
-      it under the terms of the GNU General Public License as published by
-      the Free Software Foundation; either version 2 of the License, or
-      (at your option) any later version.
-
-      This program is distributed in the hope that it will be useful,
-      but WITHOUT ANY WARRANTY; without even the implied warranty of
-      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-      GNU General Public License for more details.
-
-      You should have received a copy of the GNU General Public License
-      along with this program; if not, write to the Free Software Foundation,
-      Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
-
-  ---------------------------------------------------------------------------*/
-
-#ifndef TRUE
-#  define TRUE 1
-#  define FALSE 0
-#endif
-
-#ifndef MAX
-#  define MAX(a,b)  ((a) > (b)? (a) : (b))
-#  define MIN(a,b)  ((a) < (b)? (a) : (b))
-#endif
-
-#ifdef DEBUG
-#  define Trace(x)  {fprintf x ; fflush(stderr); fflush(stdout);}
-#else
-#  define Trace(x)  ;
-#endif
-
-#define TEXT_TITLE    0x01
-#define TEXT_AUTHOR   0x02
-#define TEXT_DESC     0x04
-#define TEXT_COPY     0x08
-#define TEXT_EMAIL    0x10
-#define TEXT_URL      0x20
-
-#define TEXT_TITLE_OFFSET        0
-#define TEXT_AUTHOR_OFFSET      72
-#define TEXT_COPY_OFFSET     (2*72)
-#define TEXT_EMAIL_OFFSET    (3*72)
-#define TEXT_URL_OFFSET      (4*72)
-#define TEXT_DESC_OFFSET     (5*72)
-
-typedef unsigned char   uch;
-typedef unsigned short  ush;
-typedef unsigned long   ulg;
-
-typedef struct _mainprog_info {
-    double gamma;
-    long width;
-    long height;
-    time_t modtime;
-    FILE *infile;
-    FILE *outfile;
-    void *png_ptr;
-    void *info_ptr;
-    uch *image_data;
-    uch **row_pointers;
-    char *title;
-    char *author;
-    char *desc;
-    char *copyright;
-    char *email;
-    char *url;
-    int filter;    /* command-line-filter flag, not PNG row filter! */
-    int pnmtype;
-    int sample_depth;
-    int interlaced;
-    int have_bg;
-    int have_time;
-    int have_text;
-    jmp_buf jmpbuf;
-    uch bg_red;
-    uch bg_green;
-    uch bg_blue;
-} mainprog_info;
-
-
-/* prototypes for public functions in writepng.c */
-
-void writepng_version_info(void);
-
-int writepng_init(mainprog_info *mainprog_ptr);
-
-int writepng_encode_image(mainprog_info *mainprog_ptr);
-
-int writepng_encode_row(mainprog_info *mainprog_ptr);
-
-int writepng_encode_finish(mainprog_info *mainprog_ptr);
-
-void writepng_cleanup(mainprog_info *mainprog_ptr);
diff --git a/contrib/pngminim/decoder/README b/contrib/pngminim/decoder/README
deleted file mode 100644
index 4f71082..0000000
--- a/contrib/pngminim/decoder/README
+++ /dev/null
@@ -1,6 +0,0 @@
-This demonstrates the use of PNG_USER_CONFIG and pngusr.h
-
-To build a minimal read-only decoder, run
-    gather.sh  # to collect needed files from pngminus, libpng, and zlib
-    make -f makefile.std
- 
diff --git a/contrib/pngminim/decoder/gather.sh b/contrib/pngminim/decoder/gather.sh
deleted file mode 100755
index e28ddaf..0000000
--- a/contrib/pngminim/decoder/gather.sh
+++ /dev/null
@@ -1,8 +0,0 @@
-cp ../../pngminus/png2pnm.c pngm2pnm.c
-cp ../../../*.h .
-cp ../../../*.c .
-rm example.c pnggccrd.c pngvcrd.c pngtest.c pngpread.c
-# change the following 2 lines if zlib is somewhere else
-cp ../../../../zlib/*.h .
-cp ../../../../zlib/*.c .
-rm minigzip.c example.c compress.c deflate.c 
diff --git a/contrib/pngminim/decoder/makefile.std b/contrib/pngminim/decoder/makefile.std
deleted file mode 100644
index 27e04cb..0000000
--- a/contrib/pngminim/decoder/makefile.std
+++ /dev/null
@@ -1,44 +0,0 @@
-# Makefile for PngMinus (pngm2pnm)
-# Linux / Unix
-
-#CC=cc
-CC=gcc
-LD=$(CC)
-
-RM=rm -f
-
-CFLAGS=-DPNG_USER_CONFIG -DNO_GZCOMPRESS -DNO_GZIP \
-       -DdeflateParams\(a,b,c\)=Z_OK -I. -O1
-
-C=.c
-O=.o
-L=.a
-E=
-
-ZOBJS  = adler32$(O) crc32$(O) gzio$(O) \
-	 infback$(O) inffast$(O) inflate$(O) inftrees$(O) \
-	 trees$(O) uncompr$(O) zutil$(O)
-
-OBJS  = pngm2pnm$(O) png$(O) pngerror$(O) pngget$(O) pngmem$(O) \
-	pngread$(O) pngrio$(O) pngrtran$(O) pngrutil$(O) \
-	pngset$(O) pngtrans$(O)  $(ZOBJS)
-
-# implicit make rules -------------------------------------------------------
-
-.c$(O): png.h pngconf.h pngusr.h zlib.h
-	$(CC) -c $(CFLAGS) $<
-
-# dependencies
-
-all: pngm2pnm$(E)
-
-pngm2pnm$(E): $(OBJS)
-	$(LD) -o pngm2pnm$(E) $(OBJS)
-	strip pngm2pnm$(E)
-
-clean:
-	$(RM) pngm2pnm$(O)
-	$(RM) pngm2pnm$(E)
-	$(RM) $(OBJS)
-
-# End of makefile for pngm2pnm
diff --git a/contrib/pngminim/decoder/pngusr.h b/contrib/pngminim/decoder/pngusr.h
deleted file mode 100644
index f94b83a..0000000
--- a/contrib/pngminim/decoder/pngusr.h
+++ /dev/null
@@ -1,67 +0,0 @@
-/* minrdpngconf.h: headers to make a minimal png-read-only library
- * For conditions of distribution and use, see copyright notice in png.h
- * Copyright (c) 2007 Glenn Randers-Pehrson
- * Derived from pngcrush.h, Copyright 1998-2007, Glenn Randers-Pehrson
- */
-
-#ifndef MINRDPNGCONF_H
-#define MINRDPNGCONF_H
-
-#define PNG_NO_GLOBAL_ARRAYS
-
-#define PNG_NO_WARNINGS
-#define png_warning(s1,s2) ""
-#define png_chunk_warning(s1,s2) ""
-#define PNG_NO_ERROR_TEXT
-#define png_error(s1,s2) png_err(s1)
-#define png_chunk_error(s1,s2) png_err(s1)
-
-#define PNG_NO_ASSEMBLER_CODE
-#define PNG_NO_OPTIMIZED_CODE
-#define PNG_NO_READ_GAMMA
-#define PNG_NO_READ_BACKGROUND
-#define PNG_NO_READ_DITHER
-#define PNG_NO_READ_INVERT
-#define PNG_NO_READ_SHIFT
-#define PNG_NO_READ_PACK
-#define PNG_NO_READ_PACKSWAP
-#define PNG_NO_READ_FILLER
-#define PNG_NO_READ_SWAP_ALPHA
-#define PNG_NO_READ_INVERT_ALPHA
-#define PNG_NO_READ_RGB_TO_GRAY
-#define PNG_NO_READ_USER_TRANSFORM
-#define PNG_NO_READ_bKGD
-#define PNG_NO_READ_cHRM
-#define PNG_NO_READ_gAMA
-#define PNG_NO_READ_hIST
-#define PNG_NO_READ_iCCP
-#define PNG_NO_READ_pCAL
-#define PNG_NO_READ_pHYs
-#define PNG_NO_READ_sBIT
-#define PNG_NO_READ_sCAL
-#define PNG_NO_READ_sPLT
-#define PNG_NO_READ_TEXT
-#define PNG_NO_READ_tIME
-#define PNG_NO_READ_UNKNOWN_CHUNKS
-#define PNG_NO_READ_USER_CHUNKS
-#define PNG_NO_READ_EMPTY_PLTE
-#define PNG_NO_READ_OPT_PLTE
-#define PNG_NO_READ_STRIP_ALPHA
-#define PNG_NO_READ_oFFs
-#define PNG_NO_WARN_UNINITIALIZED_ROW
-
-#define PNG_NO_WRITE_SUPPORTED
-
-#define PNG_NO_INFO_IMAGE
-#define PNG_NO_USER_MEM
-#define PNG_NO_FIXED_POINT_SUPPORTED
-#define PNG_NO_MNG_FEATURES
-#define PNG_NO_USER_TRANSFORM_PTR
-#define PNG_NO_HANDLE_AS_UNKNOWN
-#define PNG_NO_CONSOLE_IO
-#define PNG_NO_ZALLOC_ZERO
-#define PNG_NO_ERROR_NUMBERS
-#define PNG_NO_EASY_ACCESS
-#define PNG_NO_PROGRESSIVE_READ
-
-#endif /* MINRDPNGCONF_H */
diff --git a/contrib/pngminim/encoder/README b/contrib/pngminim/encoder/README
deleted file mode 100644
index 4a68fc8..0000000
--- a/contrib/pngminim/encoder/README
+++ /dev/null
@@ -1,6 +0,0 @@
-This demonstrates the use of PNG_USER_CONFIG and pngusr.h
-
-To build a minimal write-only encoder, run
-    gather.sh  # to collect needed files from pngminus, libpng, and zlib
-    make -f makefile.std
- 
diff --git a/contrib/pngminim/encoder/dummy_inflate.c b/contrib/pngminim/encoder/dummy_inflate.c
deleted file mode 100644
index 1422edb..0000000
--- a/contrib/pngminim/encoder/dummy_inflate.c
+++ /dev/null
@@ -1,27 +0,0 @@
-#include "zlib.h"
-
-int ZEXPORT inflate(strm, flush)
-z_streamp strm;
-int flush;
-{ return Z_OK ; }
-
-int ZEXPORT inflateReset(strm)
-z_streamp strm;
-{ return Z_OK ; }
-
-int ZEXPORT inflateEnd(strm)
-z_streamp strm;
-{ return Z_STREAM_ERROR ; }
-
-int ZEXPORT inflateInit_(strm, version, stream_size)
-z_streamp strm;
-const char *version;
-int stream_size;
-{ return Z_OK ; }
-
-int ZEXPORT inflateInit2_(strm, windowBits, version, stream_size)
-z_streamp strm;
-int windowBits;
-const char *version;
-int stream_size;
-{ return Z_STREAM_ERROR ; }
diff --git a/contrib/pngminim/encoder/gather.sh b/contrib/pngminim/encoder/gather.sh
deleted file mode 100755
index 7b0c803..0000000
--- a/contrib/pngminim/encoder/gather.sh
+++ /dev/null
@@ -1,9 +0,0 @@
-cp ../../pngminus/pnm2png.c pnm2pngm.c
-cp ../../../*.h .
-cp ../../../*.c .
-rm example.c pnggccrd.c pngvcrd.c pngtest.c pngr*.c
-# Change the next 2 lines if zlib is somewhere else.
-cp ../../../../zlib/*.h .
-cp ../../../../zlib/*.c .
-rm inf*.[ch]
-rm minigzip.c example.c
diff --git a/contrib/pngminim/encoder/makefile.std b/contrib/pngminim/encoder/makefile.std
deleted file mode 100644
index 1182b5b..0000000
--- a/contrib/pngminim/encoder/makefile.std
+++ /dev/null
@@ -1,43 +0,0 @@
-# Makefile for PngMinus (pnm2pngm)
-# Linux / Unix
-
-#CC=cc
-CC=gcc
-LD=$(CC)
-
-RM=rm -f
-
-CFLAGS=-DPNG_USER_CONFIG -DNO_GZIP -I. -O1
-
-C=.c
-O=.o
-L=.a
-E=
-
-ZOBJS  = adler32$(O) compress$(O) crc32$(O) deflate$(O) gzio$(O) \
-	 dummy_inflate$(O) \
-	 trees$(O) uncompr$(O) zutil$(O)
-
-OBJS  = pnm2pngm$(O) png$(O) pngerror$(O) pngget$(O) pngmem$(O) \
-	pngset$(O) pngtrans$(O) pngwio$(O) pngwrite$(O) \
-	pngwtran$(O) pngwutil$(O) $(ZOBJS)
-
-# implicit make rules -------------------------------------------------------
-
-.c$(O): png.h pngconf.h pngusr.h zlib.h
-	$(CC) -c $(CFLAGS) $<
-
-# dependencies
-
-all: pnm2pngm$(E)
-
-pnm2pngm$(E): $(OBJS)
-	$(LD) -o pnm2pngm$(E) $(OBJS)
-	strip pnm2pngm$(E)
-
-clean:
-	$(RM) pnm2pngm$(O)
-	$(RM) pnm2pngm$(E)
-	$(RM) $(OBJS)
-
-# End of makefile for pnm2pngm
diff --git a/contrib/pngminim/encoder/pngusr.h b/contrib/pngminim/encoder/pngusr.h
deleted file mode 100644
index 904673a..0000000
--- a/contrib/pngminim/encoder/pngusr.h
+++ /dev/null
@@ -1,66 +0,0 @@
-/* minwrpngconf.h: headers to make a minimal png-write-only library
- * For conditions of distribution and use, see copyright notice in png.h
- * Copyright (c) 2007 Glenn Randers-Pehrson
- * Derived from pngcrush.h, Copyright 1998-2007, Glenn Randers-Pehrson
- */
-
-#ifndef MINWRPNGCONF_H
-#define MINWRPNGCONF_H
-
-#define PNG_NO_GLOBAL_ARRAYS
-
-#define PNG_NO_READ_SUPPORTED
-
-#define PNG_NO_WARNINGS
-#define png_warning(s1,s2) ""
-#define png_chunk_warning(s1,s2) ""
-#define PNG_NO_ERROR_TEXT
-#define png_error(s1,s2) png_err(s1)
-#define png_chunk_error(s1,s2) png_err(s1)
-
-#define PNG_NO_WRITE_BACKGROUND
-#define PNG_NO_WRITE_GAMMA
-#define PNG_NO_WRITE_DITHER
-#define PNG_NO_WRITE_INVERT
-#define PNG_NO_WRITE_SHIFT
-#define PNG_NO_WRITE_PACK
-#define PNG_NO_WRITE_PACKSWAP
-#define PNG_NO_WRITE_FILLER
-#define PNG_NO_WRITE_SWAP_ALPHA
-#define PNG_NO_WRITE_INVERT_ALPHA
-#define PNG_NO_WRITE_RGB_TO_GRAY
-#define PNG_NO_WRITE_USER_TRANSFORM
-#define PNG_NO_WRITE_bKGD
-#define PNG_NO_WRITE_cHRM
-#define PNG_NO_WRITE_gAMA
-#define PNG_NO_WRITE_sRGB
-#define PNG_NO_WRITE_hIST
-#define PNG_NO_WRITE_iCCP
-#define PNG_NO_WRITE_oFFs
-#define PNG_NO_WRITE_pCAL
-#define PNG_NO_WRITE_pHYs
-#define PNG_NO_WRITE_sBIT
-#define PNG_NO_WRITE_sCAL
-#define PNG_NO_WRITE_sPLT
-#define PNG_NO_WRITE_TEXT
-#define PNG_NO_WRITE_tIME
-#define PNG_NO_WRITE_UNKNOWN_CHUNKS
-#define PNG_NO_WRITE_USER_CHUNKS
-#define PNG_NO_WRITE_EMPTY_PLTE
-#define PNG_NO_WRITE_OPT_PLTE
-#define PNG_NO_WRITE_FILTER
-#define PNG_NO_WRITE_WEIGHTED_FILTER
-#define PNG_NO_WRITE_INTERLACING_SUPPORTED
-
-#define PNG_NO_INFO_IMAGE
-#define PNG_NO_USER_MEM
-#define PNG_NO_FIXED_POINT_SUPPORTED
-#define PNG_NO_MNG_FEATURES
-#define PNG_NO_USER_TRANSFORM_PTR
-#define PNG_NO_HANDLE_AS_UNKNOWN
-#define PNG_NO_CONSOLE_IO
-#define PNG_NO_ZALLOC_ZERO
-#define PNG_NO_ERROR_NUMBERS
-#define PNG_NO_EASY_ACCESS
-
-#endif /* MINWRPNGCONF_H */
diff --git a/contrib/pngminus/README b/contrib/pngminus/README
deleted file mode 100644
index bbe7407..0000000
--- a/contrib/pngminus/README
+++ /dev/null
@@ -1,153 +0,0 @@
-PngMinus
---------
-(copyright Willem van Schaik, 1999)
-
-
-License
--------
-
-Permission to use, copy, modify, and distribute this software and
-its documentation for any purpose and without fee is hereby granted,
-provided that the above copyright notice appear in all copies and
-that both that copyright notice and this permission notice appear in
-supporting documentation. This software is provided "as is" without
-express or implied warranty.
-
-
-Some history
-------------
-Soon after the creation of PNG in 1995, the need was felt for a set of
-pnmtopng / pngtopnm utilities. Independantly Alexander Lehmann and I
-(Willem van Schaik) started such a project. Luckily we discovered this
-and merged the two together into pnmtopng.tar.gz, which is available
-from a/o ftp://ftp.simplesystems.org/pub/libpng/png/.
-
-These two utilities have many, many options and make use of most of the
-features of PNG, like gamma, alpha, sbit, text-chunks, etc. This makes
-the utilities quite complex and by now not anymore very maintainable.
-When we wrote these programs, libpng was still in an early stage.
-Therefore, lots of the functionality that we put in our software can now
-be done using transform-functions in libpng.
-
-Finally, to compile these programs, you need to have installed and
-compiled three libraries: libpng, zlib and netpbm. Especially the latter
-makes the whole setup a bit bulky. But that's unavoidable given the many
-features of pnmtopng.
-
-
-What now
---------
-At this moment libpng is in a very stable state and can do much of the
-work done in pnmtopng. Also, pnmtopng needs to be upgraded to the new
-interface of libpng. Hence, it is time for a rewrite from the ground up
-of pnmtopng and pngtopnm. This will happen in the near future (stay
-tuned). The new package will get a different name to distinguish it from
-the old one: PngPlus.
-
-To experiment a bit with the new interface of libpng, I started off with
-a small prototype that contains only the basic functionality. It doesn't
-have any of the options to read or write special chunks and it will do
-no gamma correction. But this makes it also a simple program that is
-quite easy to understand and can serve well as a template for other
-software developments. (By now there are of course a couple of programs,
-like Greg Roelofs' rpng/wpng, that can be used just as good.)
-
-
-Can and can not
----------------
-As this is the small brother of the future PngPlus, I called this fellow
-PngMinus. Because I started this development in good-old Turbo-C, I
-avoided the use the netpbm library, which requires DOS extenders. Again,
-another reason to call it PngMinus (minus netpbm :-). So, part of the
-program are some elementary routines to read / write pgm- and ppm-files.
-It does not read b&w pbm-files.
-
-The downside of this approach is that you can not use them on images
-that require blocks of memory bigger than 64k (the DOS version). For
-larger images you will get an out-of-memory error.
-
-As said before, PngMinus doesn't correct for gamma. When reading
-png-files you can do this just as well by piping the output of png2pnm
-to pnmgamma, one of the standard PbmPlus tools. This same scenario will
-most probably also be followed in the full-blown future PngPlus, with
-the addition of course of the possibility to create gamma-chunks when
-writing png-files.
-
-On the other hand it supports alpha-channels. When reading a png-image
-you can write the alpha-channel into a pgm-file. And when creating an
-RGB+A png-image, you just combine a ppm-file with a corresponding
-pgm-file containing the alpha-channel. When reading, transparency chunks
-are converted into an alpha-channel and from there on treated the same
-way.
-
-Finally you can opt for writing ascii or binary pgm- and ppm-files. When
-the bit-depth is 16, the format will always be ascii.
-
-
-Using it
---------
-To distinguish them from pnmtopng and PngPlus, the utilities are named
-png2pnm and pnm2png (2 instead of to). The input- and output-files can
-be given as parameters or through redirection. Therefore the programs
-can be part of a pipe.
-
-To list the options type "png2pnm -h" or "pnm2png -h".
-
-
-Just like Scandinavian furniture
---------------------------------
-You have to put it together yourself. I did test the software under
-MS-DOS with Turbo-C 3.0 and under RedHat Linux 4.2 with gcc. In both
-cases I used libpng-1.0.4 and zlib-1.1.3. Later versions should be OK,
-however some older libpng versions have a bug in pngmem.c when using
-Turbo-C 3.0 (see below).
-
-You can build it using one of the two makefiles (make -f makefile.###)
-or use the batch/script files pngminus.bat / pngminus.sh. This assumes
-that you have built the libraries in ../libpng and ../zlib. Using Linux,
-make sure that you have built libpng with makefile.std and not
-makefile.linux (also called .lnx in earlier versions of libpng). The
-latter creates a .so shared-library, while the PngMinus makefile assumes
-a normal .a static library.
-
-If you create a ../pngsuite directory and then store the basn####.png
-files from PngSuite (http://www.schaik.com/pngsuite/) in there, you can
-test in one go the proper functioning of PngMinus, see png2pnm.bat and
-pnm2png.bat (or the .sh versions).
-
-
-Warranty
--------
-Please, remember that this was just a small experiment to learn a few
-things. It will have many unforeseen features <vbg>. Who said bugs? Use
-it when you are in need for something simple or when you want to start
-developing your own stuff.
-
-
-The Turbo bug
--------------
-** pngmem.old
-          hptr = (png_byte huge *)((long)(hptr) & 0xfffffff0L);
-          hptr += 16L;
-** pngmem.c
-          hptr = (png_byte huge *)((long)(hptr) & 0xfffffff0L);
-          hptr = hptr + 16L;
-**
-
-** pngmem.old
-          png_ptr->offset_table_ptr[i] = (png_bytep)hptr;
-          hptr += (png_uint_32)65536L;
-** pngmem.c
-          png_ptr->offset_table_ptr[i] = (png_bytep)hptr;
-          hptr = hptr + 65536L;
-**
-
-
-The end
--------
-Willem van Schaik
-mailto:willem@schaik.com
-http://www.schaik.com/png/
--------
-Oct 1999
-
diff --git a/contrib/pngminus/makefile.std b/contrib/pngminus/makefile.std
deleted file mode 100644
index 2fb061b..0000000
--- a/contrib/pngminus/makefile.std
+++ /dev/null
@@ -1,65 +0,0 @@
-# Makefile for PngMinus (png2pnm and pnm2png)
-# Linux / Unix
-
-#CC=cc
-CC=gcc
-LD=$(CC)
-
-RM=rm -f
-
-#PNGPATH = /usr/local
-#PNGINC = -I$(PNGPATH)/include/libpng12
-#PNGLIB = -L$(PNGPATH)/lib -lpng12
-#PNGLIBS = $(PNGPATH)/lib/libpng12.a
-PNGINC = -I../..
-PNGLIB = -L../.. -lpng
-PNGLIBS = ../../libpng.a
-
-#ZPATH = /usr/local
-#ZINC = -I$(ZPATH)/include
-#ZLIB = -L$(ZPATH)/lib -lz
-#ZLIBS = $(ZPATH)/lib/libz.a
-ZINC = -I../../../zlib
-ZLIB = -L../../../zlib -lz
-ZLIBS = ../../../zlib/libz.a
-
-CFLAGS=-O3 $(PNGINC) $(ZINC)
-LDFLAGS=$(PNGLIB) $(ZLIB)
-LDFLAGSS=$(PNGLIBS) $(ZLIBS)
-C=.c
-O=.o
-L=.a
-E=
-
-# dependencies
-
-#all: png2pnm$(E) pnm2png$(E)
-all: png2pnm$(E) pnm2png$(E) png2pnm-static$(E) pnm2png-static$(E)
-
-png2pnm$(O): png2pnm$(C)
-	$(CC) -c $(CFLAGS) png2pnm$(C)
-
-png2pnm$(E): png2pnm$(O)
-	$(LD) -o png2pnm$(E) png2pnm$(O) $(LDFLAGS) -lm
-
-png2pnm-static$(E): png2pnm$(O)
-	$(LD) -o png2pnm-static$(E) png2pnm$(O) $(LDFLAGSS) -lm
-
-pnm2png$(O): pnm2png$(C)
-	$(CC) -c $(CFLAGS) pnm2png$(C)
-
-pnm2png$(E): pnm2png$(O)
-	$(LD) -o pnm2png$(E) pnm2png$(O) $(LDFLAGS) -lm
-
-pnm2png-static$(E): pnm2png$(O)
-	$(LD) -o pnm2png-static$(E) pnm2png$(O) $(LDFLAGSS) -lm
-
-clean:
-	$(RM) png2pnm$(O)
-	$(RM) pnm2png$(O)
-	$(RM) png2pnm$(E)
-	$(RM) pnm2png$(E)
-	$(RM) png2pnm-static$(E)
-	$(RM) pnm2png-static$(E)
-
-# End of makefile for png2pnm / pnm2png
diff --git a/contrib/pngminus/makefile.tc3 b/contrib/pngminus/makefile.tc3
deleted file mode 100644
index 404f18d..0000000
--- a/contrib/pngminus/makefile.tc3
+++ /dev/null
@@ -1,38 +0,0 @@
-# Makefile for PngMinus (png2pnm and pnm2png)
-# TurboC++ 3.0
-
-CC=tcc -Ic:\tc3\inc
-LD=tcc -Lc:\tc3\lib
-LB=tlib
-RM=del
-CP=copy
-MODEL=l
-CCFLAGS=-O -m$(MODEL) -I..\libpng -I..\zlib
-LDFLAGS=-m$(MODEL) -L..\libpng -L..\zlib
-C=.c
-O=.obj
-L=.lib
-E=.exe
-
-# dependencies
-
-all: png2pnm$(E) pnm2png$(E)
-
-png2pnm$(O): png2pnm$(C)
-        $(CC) -c $(CCFLAGS) png2pnm$(C)
-
-png2pnm$(E): png2pnm$(O)
-        $(LD) $(LDFLAGS) png2pnm$(O) libpng$(L) zlib$(L)
-
-pnm2png$(O): pnm2png$(C)
-        $(CC) -c $(CCFLAGS) pnm2png$(C)
-
-pnm2png$(E): pnm2png$(O)
-        $(LD) $(LDFLAGS) pnm2png$(O) libpng$(L) zlib$(L)
-
-clean:
-        $(RM) *$(O)
-        $(RM) *$(E)
-
-# End of makefile for png2pnm / pnm2png
-
diff --git a/contrib/pngminus/makevms.com b/contrib/pngminus/makevms.com
deleted file mode 100644
index 00561bc..0000000
--- a/contrib/pngminus/makevms.com
+++ /dev/null
@@ -1,92 +0,0 @@
-$!------------------------------------------------------------------------------
-$! make Contrib programs of libpng under OpenVMS
-$!
-$!
-$! Look for the compiler used
-$!
-$ zlibsrc = "[---.zlib]"
-$ ccopt="/include=(''zlibsrc',[--])"
-$ if f$getsyi("HW_MODEL").ge.1024
-$ then
-$  ccopt = "/prefix=all"+ccopt
-$  comp  = "__decc__=1"
-$  if f$trnlnm("SYS").eqs."" then define sys sys$library:
-$ else
-$  if f$search("SYS$SYSTEM:DECC$COMPILER.EXE").eqs.""
-$   then
-$    if f$trnlnm("SYS").eqs."" then define sys sys$library:
-$    if f$search("SYS$SYSTEM:VAXC.EXE").eqs.""
-$     then
-$      comp  = "__gcc__=1"
-$      CC :== GCC
-$     else
-$      comp = "__vaxc__=1"
-$     endif
-$   else
-$    if f$trnlnm("SYS").eqs."" then define sys decc$library_include:
-$    ccopt = "/decc/prefix=all"+ccopt
-$    comp  = "__decc__=1"
-$  endif
-$ endif
-$ open/write lopt lib.opt
-$ write lopt "[--]libpng.olb/lib"
-$ write lopt "''zlibsrc'libz.olb/lib"
-$ close lopt
-$ open/write xopt x11.opt
-$ write xopt "sys$library:decw$xlibshr.exe/share"
-$ close xopt
-$ write sys$output "Compiling PNG contrib programs ..."
-$   write sys$output "Building pnm2png..."
-$   CALL MAKE pnm2png.OBJ "cc ''CCOPT' pnm2png" -
-	pnm2png.c
-$   call make pnm2png.exe -
-	"LINK pnm2png,lib.opt/opt" -
-	pnm2png.obj
-$   write sys$output "Building png2pnm..."
-$   CALL MAKE png2pnm.OBJ "cc ''CCOPT' png2pnm" -
-	png2pnm.c
-$   call make png2pnm.exe -
-	"LINK png2pnm,lib.opt/opt" -
-	png2pnm.obj
-$ exit
-$!
-$!
-$MAKE: SUBROUTINE   !SUBROUTINE TO CHECK DEPENDENCIES
-$ V = 'F$Verify(0)
-$! P1 = What we are trying to make
-$! P2 = Command to make it
-$! P3 - P8  What it depends on
-$
-$ If F$Search(P1) .Eqs. "" Then Goto Makeit
-$ Time = F$CvTime(F$File(P1,"RDT"))
-$arg=3
-$Loop:
-$       Argument = P'arg
-$       If Argument .Eqs. "" Then Goto Exit
-$       El=0
-$Loop2:
-$       File = F$Element(El," ",Argument)
-$       If File .Eqs. " " Then Goto Endl
-$       AFile = ""
-$Loop3:
-$       OFile = AFile
-$       AFile = F$Search(File)
-$       If AFile .Eqs. "" .Or. AFile .Eqs. OFile Then Goto NextEl
-$       If F$CvTime(F$File(AFile,"RDT")) .Ges. Time Then Goto Makeit
-$       Goto Loop3
-$NextEL:
-$       El = El + 1
-$       Goto Loop2
-$EndL:
-$ arg=arg+1
-$ If arg .Le. 8 Then Goto Loop
-$ Goto Exit
-$
-$Makeit:
-$ VV=F$VERIFY(0)
-$ write sys$output P2
-$ 'P2
-$ VV='F$Verify(VV)
-$Exit:
-$ If V Then Set Verify
-$ENDSUBROUTINE
diff --git a/contrib/pngminus/png2pnm.bat b/contrib/pngminus/png2pnm.bat
deleted file mode 100644
index 449cf36..0000000
--- a/contrib/pngminus/png2pnm.bat
+++ /dev/null
@@ -1,41 +0,0 @@
-REM -- grayscale
-png2pnm.exe -noraw ..\pngsuite\basn0g01.png basn0g01.pgm
-png2pnm.exe -noraw ..\pngsuite\basn0g02.png basn0g02.pgm
-png2pnm.exe -noraw ..\pngsuite\basn0g04.png basn0g04.pgm
-png2pnm.exe -noraw ..\pngsuite\basn0g08.png basn0g08.pgm
-png2pnm.exe -noraw ..\pngsuite\basn0g16.png basn0g16.pgm
-REM -- full-color
-png2pnm.exe -noraw ..\pngsuite\basn2c08.png basn2c08.ppm
-png2pnm.exe -noraw ..\pngsuite\basn2c16.png basn2c16.ppm
-REM -- palletted
-png2pnm.exe -noraw ..\pngsuite\basn3p01.png basn3p01.ppm
-png2pnm.exe -noraw ..\pngsuite\basn3p02.png basn3p02.ppm
-png2pnm.exe -noraw ..\pngsuite\basn3p04.png basn3p04.ppm
-png2pnm.exe -noraw ..\pngsuite\basn3p08.png basn3p08.ppm
-REM -- gray with alpha-channel
-png2pnm.exe -noraw ..\pngsuite\basn4a08.png basn4a08.pgm
-png2pnm.exe -noraw ..\pngsuite\basn4a16.png basn4a16.pgm
-REM -- color with alpha-channel
-png2pnm.exe -noraw -alpha basn6a08.pgm ..\pngsuite\basn6a08.png basn6a08.ppm
-png2pnm.exe -noraw -alpha basn6a16.pgm ..\pngsuite\basn6a16.png basn6a16.ppm
-REM -- grayscale
-png2pnm.exe -raw ..\pngsuite\basn0g01.png rawn0g01.pgm
-png2pnm.exe -raw ..\pngsuite\basn0g02.png rawn0g02.pgm
-png2pnm.exe -raw ..\pngsuite\basn0g04.png rawn0g04.pgm
-png2pnm.exe -raw ..\pngsuite\basn0g08.png rawn0g08.pgm
-png2pnm.exe -raw ..\pngsuite\basn0g16.png rawn0g16.pgm
-REM -- full-color
-png2pnm.exe -raw ..\pngsuite\basn2c08.png rawn2c08.ppm
-png2pnm.exe -raw ..\pngsuite\basn2c16.png rawn2c16.ppm
-REM -- palletted
-png2pnm.exe -raw ..\pngsuite\basn3p01.png rawn3p01.ppm
-png2pnm.exe -raw ..\pngsuite\basn3p02.png rawn3p02.ppm
-png2pnm.exe -raw ..\pngsuite\basn3p04.png rawn3p04.ppm
-png2pnm.exe -raw ..\pngsuite\basn3p08.png rawn3p08.ppm
-REM -- gray with alpha-channel
-png2pnm.exe -raw ..\pngsuite\basn4a08.png rawn4a08.pgm
-png2pnm.exe -raw ..\pngsuite\basn4a16.png rawn4a16.pgm
-REM -- color with alpha-channel
-png2pnm.exe -noraw -alpha rawn6a08.pgm ..\pngsuite\basn6a08.png rawn6a08.ppm
-png2pnm.exe -noraw -alpha rawn6a16.pgm ..\pngsuite\basn6a16.png rawn6a16.ppm
-
diff --git a/contrib/pngminus/png2pnm.c b/contrib/pngminus/png2pnm.c
deleted file mode 100644
index 010870a..0000000
--- a/contrib/pngminus/png2pnm.c
+++ /dev/null
@@ -1,430 +0,0 @@
-/*
- *  png2pnm.c --- conversion from PNG-file to PGM/PPM-file
- *  copyright (C) 1999 by Willem van Schaik <willem@schaik.com>
- *
- *  version 1.0 - 1999.10.15 - First version.
- *
- *  Permission to use, copy, modify, and distribute this software and
- *  its documentation for any purpose and without fee is hereby granted,
- *  provided that the above copyright notice appear in all copies and
- *  that both that copyright notice and this permission notice appear in
- *  supporting documentation. This software is provided "as is" without
- *  express or implied warranty.
- */
-
-#include <stdio.h>
-#include <stdlib.h>
-#ifdef __TURBOC__
-#include <mem.h>
-#include <fcntl.h>
-#endif
-
-#ifndef BOOL
-#define BOOL unsigned char
-#endif
-#ifndef TRUE
-#define TRUE (BOOL) 1
-#endif
-#ifndef FALSE
-#define FALSE (BOOL) 0
-#endif
-
-#ifdef __TURBOC__
-#define STDIN  0
-#define STDOUT 1
-#define STDERR 2
-#endif
-
-/* to make png2pnm verbose so we can find problems (needs to be before png.h) */
-#ifndef PNG_DEBUG
-#define PNG_DEBUG 0
-#endif
-
-#include "png.h"
-
-/* Define png_jmpbuf() in case we are using a pre-1.0.6 version of libpng */
-#ifndef png_jmpbuf
-#  define png_jmpbuf(png_ptr) ((png_ptr)->jmpbuf)
-#endif
-
-/* function prototypes */
-
-int  main (int argc, char *argv[]);
-void usage ();
-BOOL png2pnm (FILE *png_file, FILE *pnm_file, FILE *alpha_file, BOOL raw, BOOL alpha);
-
-/*
- *  main
- */
-
-int main(int argc, char *argv[])
-{
-  FILE *fp_rd = stdin;
-  FILE *fp_wr = stdout;
-  FILE *fp_al = NULL;
-  BOOL raw = TRUE;
-  BOOL alpha = FALSE;
-  int argi;
-
-  for (argi = 1; argi < argc; argi++)
-  {
-    if (argv[argi][0] == '-')
-    {
-      switch (argv[argi][1])
-      {
-        case 'n':
-          raw = FALSE;
-          break;
-        case 'r':
-          raw = TRUE;
-          break;
-        case 'a':
-          alpha = TRUE;
-          argi++;
-          if ((fp_al = fopen (argv[argi], "wb")) == NULL)
-          {
-            fprintf (stderr, "PNM2PNG\n");
-            fprintf (stderr, "Error:  can not create alpha-channel file %s\n", argv[argi]);
-            exit (1);
-          }
-          break;
-        case 'h':
-        case '?':
-          usage();
-          exit(0);
-          break;
-        default:
-          fprintf (stderr, "PNG2PNM\n");
-          fprintf (stderr, "Error:  unknown option %s\n", argv[argi]);
-          usage();
-          exit(1);
-          break;
-      } /* end switch */
-    }
-    else if (fp_rd == stdin)
-    {
-      if ((fp_rd = fopen (argv[argi], "rb")) == NULL)
-      {
-             fprintf (stderr, "PNG2PNM\n");
-            fprintf (stderr, "Error:  file %s does not exist\n", argv[argi]);
-            exit (1);
-      }
-    }
-    else if (fp_wr == stdout)
-    {
-      if ((fp_wr = fopen (argv[argi], "wb")) == NULL)
-      {
-        fprintf (stderr, "PNG2PNM\n");
-        fprintf (stderr, "Error:  can not create file %s\n", argv[argi]);
-        exit (1);
-      }
-    }
-    else
-    {
-      fprintf (stderr, "PNG2PNM\n");
-      fprintf (stderr, "Error:  too many parameters\n");
-      usage();
-      exit(1);
-    }
-  } /* end for */
-
-#ifdef __TURBOC__
-  /* set stdin/stdout if required to binary */
-  if (fp_rd == stdin)
-  {
-    setmode (STDIN, O_BINARY);
-  }
-  if ((raw) && (fp_wr == stdout))
-  {
-    setmode (STDOUT, O_BINARY);
-  }
-#endif
-
-  /* call the conversion program itself */
-  if (png2pnm (fp_rd, fp_wr, fp_al, raw, alpha) == FALSE)
-  {
-    fprintf (stderr, "PNG2PNM\n");
-    fprintf (stderr, "Error:  unsuccessful convertion of PNG-image\n");
-    exit(1);
-  }
-
-  /* close input file */
-  fclose (fp_rd);
-  /* close output file */
-  fclose (fp_wr);
-  /* close alpha file */
-  if (alpha)
-    fclose (fp_al);
-
-  return 0;
-}
-
-/*
- *  usage
- */
-
-void usage()
-{
-  fprintf (stderr, "PNG2PNM\n");
-  fprintf (stderr, "   by Willem van Schaik, 1999\n");
-#ifdef __TURBOC__
-  fprintf (stderr, "   for Turbo-C and Borland-C compilers\n");
-#else
-  fprintf (stderr, "   for Linux (and Unix) compilers\n");
-#endif
-  fprintf (stderr, "Usage:  png2pnm [options] <file>.png [<file>.pnm]\n");
-  fprintf (stderr, "   or:  ... | png2pnm [options]\n");
-  fprintf (stderr, "Options:\n");
-  fprintf (stderr, "   -r[aw]   write pnm-file in binary format (P4/P5/P6) (default)\n");
-  fprintf (stderr, "   -n[oraw] write pnm-file in ascii format (P1/P2/P3)\n");
-  fprintf (stderr, "   -a[lpha] <file>.pgm write PNG alpha channel as pgm-file\n");
-  fprintf (stderr, "   -h | -?  print this help-information\n");
-}
-
-/*
- *  png2pnm
- */
-
-BOOL png2pnm (FILE *png_file, FILE *pnm_file, FILE *alpha_file, BOOL raw, BOOL alpha)
-{
-  png_struct    *png_ptr = NULL;
-  png_info	*info_ptr = NULL;
-  png_byte      buf[8];
-  png_byte      *png_pixels = NULL;
-  png_byte      **row_pointers = NULL;
-  png_byte      *pix_ptr = NULL;
-  png_uint_32   row_bytes;
-
-  png_uint_32   width;
-  png_uint_32   height;
-  int           bit_depth;
-  int           channels;
-  int           color_type;
-  int           alpha_present;
-  int           row, col;
-  int           ret;
-  int           i;
-  long          dep_16;
-
-  /* read and check signature in PNG file */
-  ret = fread (buf, 1, 8, png_file);
-  if (ret != 8)
-    return FALSE;
-
-  ret = png_check_sig (buf, 8);
-  if (!ret)
-    return FALSE;
-
-  /* create png and info structures */
-
-  png_ptr = png_create_read_struct (PNG_LIBPNG_VER_STRING,
-    NULL, NULL, NULL);
-  if (!png_ptr)
-    return FALSE;   /* out of memory */
-
-  info_ptr = png_create_info_struct (png_ptr);
-  if (!info_ptr)
-  {
-    png_destroy_read_struct (&png_ptr, NULL, NULL);
-    return FALSE;   /* out of memory */
-  }
-
-  if (setjmp (png_jmpbuf(png_ptr)))
-  {
-    png_destroy_read_struct (&png_ptr, &info_ptr, NULL);
-    return FALSE;
-  }
-
-  /* set up the input control for C streams */
-  png_init_io (png_ptr, png_file);
-  png_set_sig_bytes (png_ptr, 8);  /* we already read the 8 signature bytes */
-
-  /* read the file information */
-  png_read_info (png_ptr, info_ptr);
-
-  /* get size and bit-depth of the PNG-image */
-  png_get_IHDR (png_ptr, info_ptr,
-    &width, &height, &bit_depth, &color_type,
-    NULL, NULL, NULL);
-
-  /* set-up the transformations */
-
-  /* transform paletted images into full-color rgb */
-  if (color_type == PNG_COLOR_TYPE_PALETTE)
-    png_set_expand (png_ptr);
-  /* expand images to bit-depth 8 (only applicable for grayscale images) */
-  if (color_type == PNG_COLOR_TYPE_GRAY && bit_depth < 8)
-    png_set_expand (png_ptr);
-  /* transform transparency maps into full alpha-channel */
-  if (png_get_valid (png_ptr, info_ptr, PNG_INFO_tRNS))
-    png_set_expand (png_ptr);
-
-#ifdef NJET
-  /* downgrade 16-bit images to 8 bit */
-  if (bit_depth == 16)
-    png_set_strip_16 (png_ptr);
-  /* transform grayscale images into full-color */
-  if (color_type == PNG_COLOR_TYPE_GRAY ||
-    color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
-    png_set_gray_to_rgb (png_ptr);
-  /* only if file has a file gamma, we do a correction */
-  if (png_get_gAMA (png_ptr, info_ptr, &file_gamma))
-    png_set_gamma (png_ptr, (double) 2.2, file_gamma);
-#endif
-
-  /* all transformations have been registered; now update info_ptr data,
-   * get rowbytes and channels, and allocate image memory */
-
-  png_read_update_info (png_ptr, info_ptr);
-
-  /* get the new color-type and bit-depth (after expansion/stripping) */
-  png_get_IHDR (png_ptr, info_ptr, &width, &height, &bit_depth, &color_type,
-    NULL, NULL, NULL);
-
-  /* check for 16-bit files */
-  if (bit_depth == 16)
-  {
-    raw = FALSE;
-#ifdef __TURBOC__
-    pnm_file->flags &= ~((unsigned) _F_BIN);
-#endif
-  }
-
-  /* calculate new number of channels and store alpha-presence */
-  if (color_type == PNG_COLOR_TYPE_GRAY)
-    channels = 1;
-  else if (color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
-    channels = 2;
-  else if (color_type == PNG_COLOR_TYPE_RGB)
-    channels = 3;
-  else if (color_type == PNG_COLOR_TYPE_RGB_ALPHA)
-    channels = 4;
-  else
-    channels = 0; /* should never happen */
-  alpha_present = (channels - 1) % 2;
-
-  /* check if alpha is expected to be present in file */
-  if (alpha && !alpha_present)
-  {
-    fprintf (stderr, "PNG2PNM\n");
-    fprintf (stderr, "Error:  PNG-file doesn't contain alpha channel\n");
-    exit (1);
-  }
-
-  /* row_bytes is the width x number of channels x (bit-depth / 8) */
-  row_bytes = png_get_rowbytes (png_ptr, info_ptr);
-
-  if ((png_pixels = (png_byte *) malloc (row_bytes * height * sizeof (png_byte))) == NULL) {
-    png_destroy_read_struct (&png_ptr, &info_ptr, NULL);
-    return FALSE;
-  }
-
-  if ((row_pointers = (png_byte **) malloc (height * sizeof (png_bytep))) == NULL)
-  {
-    png_destroy_read_struct (&png_ptr, &info_ptr, NULL);
-    free (png_pixels);
-    png_pixels = NULL;
-    return FALSE;
-  }
-
-  /* set the individual row_pointers to point at the correct offsets */
-  for (i = 0; i < (height); i++)
-    row_pointers[i] = png_pixels + i * row_bytes;
-
-  /* now we can go ahead and just read the whole image */
-  png_read_image (png_ptr, row_pointers);
-
-  /* read rest of file, and get additional chunks in info_ptr - REQUIRED */
-  png_read_end (png_ptr, info_ptr);
-
-  /* clean up after the read, and free any memory allocated - REQUIRED */
-  png_destroy_read_struct (&png_ptr, &info_ptr, (png_infopp) NULL);
-
-  /* write header of PNM file */
-
-  if ((color_type == PNG_COLOR_TYPE_GRAY) ||
-      (color_type == PNG_COLOR_TYPE_GRAY_ALPHA))
-  {
-    fprintf (pnm_file, "%s\n", (raw) ? "P5" : "P2");
-    fprintf (pnm_file, "%d %d\n", (int) width, (int) height);
-    fprintf (pnm_file, "%ld\n", ((1L << (int) bit_depth) - 1L));
-  }
-  else if ((color_type == PNG_COLOR_TYPE_RGB) ||
-           (color_type == PNG_COLOR_TYPE_RGB_ALPHA))
-  {
-    fprintf (pnm_file, "%s\n", (raw) ? "P6" : "P3");
-    fprintf (pnm_file, "%d %d\n", (int) width, (int) height);
-    fprintf (pnm_file, "%ld\n", ((1L << (int) bit_depth) - 1L));
-  }
-
-  /* write header of PGM file with alpha channel */
-
-  if ((alpha) &&
-      ((color_type == PNG_COLOR_TYPE_GRAY_ALPHA) ||
-       (color_type == PNG_COLOR_TYPE_RGB_ALPHA)))
-  {
-    fprintf (alpha_file, "%s\n", (raw) ? "P5" : "P2");
-    fprintf (alpha_file, "%d %d\n", (int) width, (int) height);
-    fprintf (alpha_file, "%ld\n", ((1L << (int) bit_depth) - 1L));
-  }
-
-  /* write data to PNM file */
-  pix_ptr = png_pixels;
-
-  for (row = 0; row < height; row++)
-  {
-    for (col = 0; col < width; col++)
-    {
-      for (i = 0; i < (channels - alpha_present); i++)
-      {
-        if (raw)
-          fputc ((int) *pix_ptr++ , pnm_file);
-        else
-          if (bit_depth == 16){
-	    dep_16 = (long) *pix_ptr++;
-            fprintf (pnm_file, "%ld ", (dep_16 << 8) + ((long) *pix_ptr++));
-          }
-          else
-            fprintf (pnm_file, "%ld ", (long) *pix_ptr++);
-      }
-      if (alpha_present)
-      {
-        if (!alpha)
-        {
-          pix_ptr++; /* alpha */
-          if (bit_depth == 16)
-            pix_ptr++;
-        }
-        else /* output alpha-channel as pgm file */
-        {
-          if (raw)
-            fputc ((int) *pix_ptr++ , alpha_file);
-          else
-            if (bit_depth == 16){
-	      dep_16 = (long) *pix_ptr++;
-              fprintf (alpha_file, "%ld ", (dep_16 << 8) + (long) *pix_ptr++);
-	    }  
-            else
-              fprintf (alpha_file, "%ld ", (long) *pix_ptr++);
-        }
-      } /* if alpha_present */
-
-      if (!raw)
-        if (col % 4 == 3)
-          fprintf (pnm_file, "\n");
-    } /* end for col */
-
-    if (!raw)
-      if (col % 4 != 0)
-        fprintf (pnm_file, "\n");
-  } /* end for row */
-
-  if (row_pointers != (unsigned char**) NULL)
-    free (row_pointers);
-  if (png_pixels != (unsigned char*) NULL)
-    free (png_pixels);
-
-  return TRUE;
-
-} /* end of source */
-
diff --git a/contrib/pngminus/png2pnm.sh b/contrib/pngminus/png2pnm.sh
deleted file mode 100644
index b1c0537..0000000
--- a/contrib/pngminus/png2pnm.sh
+++ /dev/null
@@ -1,42 +0,0 @@
-#!/bin/sh
-# -- grayscale
-./png2pnm -noraw ../pngsuite/basn0g01.png basn0g01.pgm
-./png2pnm -noraw ../pngsuite/basn0g02.png basn0g02.pgm
-./png2pnm -noraw ../pngsuite/basn0g04.png basn0g04.pgm
-./png2pnm -noraw ../pngsuite/basn0g08.png basn0g08.pgm
-./png2pnm -noraw ../pngsuite/basn0g16.png basn0g16.pgm
-# -- full-color
-./png2pnm -noraw ../pngsuite/basn2c08.png basn2c08.ppm
-./png2pnm -noraw ../pngsuite/basn2c16.png basn2c16.ppm
-# -- palletted
-./png2pnm -noraw ../pngsuite/basn3p01.png basn3p01.ppm
-./png2pnm -noraw ../pngsuite/basn3p02.png basn3p02.ppm
-./png2pnm -noraw ../pngsuite/basn3p04.png basn3p04.ppm
-./png2pnm -noraw ../pngsuite/basn3p08.png basn3p08.ppm
-# -- gray with alpha-channel
-./png2pnm -noraw ../pngsuite/basn4a08.png basn4a08.pgm
-./png2pnm -noraw ../pngsuite/basn4a16.png basn4a16.pgm
-# -- color with alpha-channel
-./png2pnm -noraw -alpha basn6a08.pgm ../pngsuite/basn6a08.png basn6a08.ppm
-./png2pnm -noraw -alpha basn6a16.pgm ../pngsuite/basn6a16.png basn6a16.ppm
-# -- grayscale
-./png2pnm -raw ../pngsuite/basn0g01.png rawn0g01.pgm
-./png2pnm -raw ../pngsuite/basn0g02.png rawn0g02.pgm
-./png2pnm -raw ../pngsuite/basn0g04.png rawn0g04.pgm
-./png2pnm -raw ../pngsuite/basn0g08.png rawn0g08.pgm
-./png2pnm -raw ../pngsuite/basn0g16.png rawn0g16.pgm
-# -- full-color
-./png2pnm -raw ../pngsuite/basn2c08.png rawn2c08.ppm
-./png2pnm -raw ../pngsuite/basn2c16.png rawn2c16.ppm
-# -- palletted
-./png2pnm -raw ../pngsuite/basn3p01.png rawn3p01.ppm
-./png2pnm -raw ../pngsuite/basn3p02.png rawn3p02.ppm
-./png2pnm -raw ../pngsuite/basn3p04.png rawn3p04.ppm
-./png2pnm -raw ../pngsuite/basn3p08.png rawn3p08.ppm
-# -- gray with alpha-channel
-./png2pnm -raw ../pngsuite/basn4a08.png rawn4a08.pgm
-./png2pnm -raw ../pngsuite/basn4a16.png rawn4a16.pgm
-# -- color with alpha-channel
-./png2pnm -noraw -alpha rawn6a08.pgm ../pngsuite/basn6a08.png rawn6a08.ppm
-./png2pnm -noraw -alpha rawn6a16.pgm ../pngsuite/basn6a16.png rawn6a16.ppm
-
diff --git a/contrib/pngminus/pngminus.bat b/contrib/pngminus/pngminus.bat
deleted file mode 100644
index 911bb8d..0000000
--- a/contrib/pngminus/pngminus.bat
+++ /dev/null
@@ -1,4 +0,0 @@
-make -f makefile.tc3
-call png2pnm.bat
-call pnm2png.bat
-
diff --git a/contrib/pngminus/pngminus.sh b/contrib/pngminus/pngminus.sh
deleted file mode 100644
index 2a0a9d8..0000000
--- a/contrib/pngminus/pngminus.sh
+++ /dev/null
@@ -1,5 +0,0 @@
-#!/bin/sh
-make -f makefile.std
-sh png2pnm.sh
-sh pnm2png.sh
-
diff --git a/contrib/pngminus/pnm2png.bat b/contrib/pngminus/pnm2png.bat
deleted file mode 100644
index f756cb8..0000000
--- a/contrib/pngminus/pnm2png.bat
+++ /dev/null
@@ -1,41 +0,0 @@
-REM -- grayscale
-pnm2png.exe basn0g01.pgm basn0g01.png
-pnm2png.exe basn0g02.pgm basn0g02.png
-pnm2png.exe basn0g04.pgm basn0g04.png
-pnm2png.exe basn0g08.pgm basn0g08.png
-pnm2png.exe basn0g16.pgm basn0g16.png
-REM -- full-color
-pnm2png.exe basn2c08.ppm basn2c08.png
-pnm2png.exe basn2c16.ppm basn2c16.png
-REM -- palletted
-pnm2png.exe basn3p01.ppm basn3p01.png
-pnm2png.exe basn3p02.ppm basn3p02.png
-pnm2png.exe basn3p04.ppm basn3p04.png
-pnm2png.exe basn3p08.ppm basn3p08.png
-REM -- gray with alpha-channel
-pnm2png.exe -alpha basn6a08.pgm basn4a08.pgm basn4a08.png
-pnm2png.exe -alpha basn6a16.pgm basn4a16.pgm basn4a16.png
-REM -- color with alpha-channel
-pnm2png.exe -alpha basn6a08.pgm basn6a08.ppm basn6a08.png
-pnm2png.exe -alpha basn6a16.pgm basn6a16.ppm basn6a16.png
-REM -- grayscale
-pnm2png.exe rawn0g01.pgm rawn0g01.png
-pnm2png.exe rawn0g02.pgm rawn0g02.png
-pnm2png.exe rawn0g04.pgm rawn0g04.png
-pnm2png.exe rawn0g08.pgm rawn0g08.png
-pnm2png.exe rawn0g16.pgm rawn0g16.png
-REM -- full-color
-pnm2png.exe rawn2c08.ppm rawn2c08.png
-pnm2png.exe rawn2c16.ppm rawn2c16.png
-REM -- palletted
-pnm2png.exe rawn3p01.ppm rawn3p01.png
-pnm2png.exe rawn3p02.ppm rawn3p02.png
-pnm2png.exe rawn3p04.ppm rawn3p04.png
-pnm2png.exe rawn3p08.ppm rawn3p08.png
-REM -- gray with alpha-channel
-pnm2png.exe -alpha rawn6a08.pgm rawn4a08.pgm rawn4a08.png
-pnm2png.exe -alpha rawn6a16.pgm rawn4a16.pgm rawn4a16.png
-REM -- color with alpha-channel
-pnm2png.exe -alpha rawn6a08.pgm rawn6a08.ppm rawn6a08.png
-pnm2png.exe -alpha rawn6a16.pgm rawn6a16.ppm rawn6a16.png
-
diff --git a/contrib/pngminus/pnm2png.c b/contrib/pngminus/pnm2png.c
deleted file mode 100644
index 4cdfad8..0000000
--- a/contrib/pngminus/pnm2png.c
+++ /dev/null
@@ -1,533 +0,0 @@
-/*
- *  pnm2png.c --- conversion from PBM/PGM/PPM-file to PNG-file
- *  copyright (C) 1999 by Willem van Schaik <willem@schaik.com>
- *
- *  version 1.0 - 1999.10.15 - First version.
- *
- *  Permission to use, copy, modify, and distribute this software and
- *  its documentation for any purpose and without fee is hereby granted,
- *  provided that the above copyright notice appear in all copies and
- *  that both that copyright notice and this permission notice appear in
- *  supporting documentation. This software is provided "as is" without
- *  express or implied warranty.
- */
-
-#include <stdio.h>
-#include <stdlib.h>
-#ifdef __TURBOC__
-#include <mem.h>
-#include <fcntl.h>
-#endif
-
-#ifndef BOOL
-#define BOOL unsigned char
-#endif
-#ifndef TRUE
-#define TRUE (BOOL) 1
-#endif
-#ifndef FALSE
-#define FALSE (BOOL) 0
-#endif
-
-#define STDIN  0
-#define STDOUT 1
-#define STDERR 2
-
-/* to make pnm2png verbose so we can find problems (needs to be before png.h) */
-#ifndef PNG_DEBUG
-#define PNG_DEBUG 0
-#endif
-
-#include "png.h"
-
-/* Define png_jmpbuf() in case we are using a pre-1.0.6 version of libpng */
-#ifndef png_jmpbuf
-#  define png_jmpbuf(png_ptr) ((png_ptr)->jmpbuf)
-#endif
-
-/* function prototypes */
-
-int  main (int argc, char *argv[]);
-void usage ();
-BOOL pnm2png (FILE *pnm_file, FILE *png_file, FILE *alpha_file, BOOL interlace, BOOL alpha);
-void get_token(FILE *pnm_file, char *token);
-png_uint_32 get_data (FILE *pnm_file, int depth);
-png_uint_32 get_value (FILE *pnm_file, int depth);
-
-/*
- *  main
- */
-
-int main(int argc, char *argv[])
-{
-  FILE *fp_rd = stdin;
-  FILE *fp_al = NULL;
-  FILE *fp_wr = stdout;
-  BOOL interlace = FALSE;
-  BOOL alpha = FALSE;
-  int argi;
-
-  for (argi = 1; argi < argc; argi++)
-  {
-    if (argv[argi][0] == '-')
-    {
-      switch (argv[argi][1])
-      {
-        case 'i':
-          interlace = TRUE;
-          break;
-        case 'a':
-          alpha = TRUE;
-          argi++;
-          if ((fp_al = fopen (argv[argi], "rb")) == NULL)
-          {
-            fprintf (stderr, "PNM2PNG\n");
-            fprintf (stderr, "Error:  alpha-channel file %s does not exist\n",
-               argv[argi]);
-            exit (1);
-          }
-          break;
-        case 'h':
-        case '?':
-          usage();
-          exit(0);
-          break;
-        default:
-          fprintf (stderr, "PNM2PNG\n");
-          fprintf (stderr, "Error:  unknown option %s\n", argv[argi]);
-          usage();
-          exit(1);
-          break;
-      } /* end switch */
-    }
-    else if (fp_rd == stdin)
-    {
-      if ((fp_rd = fopen (argv[argi], "rb")) == NULL)
-      {
-        fprintf (stderr, "PNM2PNG\n");
-        fprintf (stderr, "Error:  file %s does not exist\n", argv[argi]);
-        exit (1);
-      }
-    }
-    else if (fp_wr == stdout)
-    {
-      if ((fp_wr = fopen (argv[argi], "wb")) == NULL)
-      {
-        fprintf (stderr, "PNM2PNG\n");
-        fprintf (stderr, "Error:  can not create PNG-file %s\n", argv[argi]);
-        exit (1);
-      }
-    }
-    else
-    {
-      fprintf (stderr, "PNM2PNG\n");
-      fprintf (stderr, "Error:  too many parameters\n");
-      usage();
-      exit (1);
-    }
-  } /* end for */
-
-#ifdef __TURBOC__
-  /* set stdin/stdout to binary, we're reading the PNM always! in binary format */
-  if (fp_rd == stdin)
-  {
-    setmode (STDIN, O_BINARY);
-  }
-  if (fp_wr == stdout)
-  {
-    setmode (STDOUT, O_BINARY);
-  }
-#endif
-
-  /* call the conversion program itself */
-  if (pnm2png (fp_rd, fp_wr, fp_al, interlace, alpha) == FALSE)
-  {
-    fprintf (stderr, "PNM2PNG\n");
-    fprintf (stderr, "Error:  unsuccessful converting to PNG-image\n");
-    exit (1);
-  }
-
-  /* close input file */
-  fclose (fp_rd);
-  /* close output file */
-  fclose (fp_wr);
-  /* close alpha file */
-  if (alpha)
-    fclose (fp_al);
-
-  return 0;
-}
-
-/*
- *  usage
- */
-
-void usage()
-{
-  fprintf (stderr, "PNM2PNG\n");
-  fprintf (stderr, "   by Willem van Schaik, 1999\n");
-#ifdef __TURBOC__
-  fprintf (stderr, "   for Turbo-C and Borland-C compilers\n");
-#else
-  fprintf (stderr, "   for Linux (and Unix) compilers\n");
-#endif
-  fprintf (stderr, "Usage:  pnm2png [options] <file>.<pnm> [<file>.png]\n");
-  fprintf (stderr, "   or:  ... | pnm2png [options]\n");
-  fprintf (stderr, "Options:\n");
-  fprintf (stderr, "   -i[nterlace]   write png-file with interlacing on\n");
-  fprintf (stderr, "   -a[lpha] <file>.pgm read PNG alpha channel as pgm-file\n");
-  fprintf (stderr, "   -h | -?  print this help-information\n");
-}
-
-/*
- *  pnm2png
- */
-
-BOOL pnm2png (FILE *pnm_file, FILE *png_file, FILE *alpha_file, BOOL interlace, BOOL alpha)
-{
-  png_struct    *png_ptr = NULL;
-  png_info      *info_ptr = NULL;
-  png_byte      *png_pixels = NULL;
-  png_byte      **row_pointers = NULL;
-  png_byte      *pix_ptr = NULL;
-  png_uint_32   row_bytes;
-
-  char          type_token[16];
-  char          width_token[16];
-  char          height_token[16];
-  char          maxval_token[16];
-  int           color_type;
-  png_uint_32   width, alpha_width;
-  png_uint_32   height, alpha_height;
-  png_uint_32   maxval;
-  int           bit_depth = 0;
-  int           channels;
-  int           alpha_depth = 0;
-  int           alpha_present;
-  int           row, col;
-  BOOL          raw, alpha_raw = FALSE;
-  png_uint_32   tmp16;
-  int           i;
-
-  /* read header of PNM file */
-
-  get_token(pnm_file, type_token);
-  if (type_token[0] != 'P')
-  {
-    return FALSE;
-  }
-  else if ((type_token[1] == '1') || (type_token[1] == '4'))
-  {
-    raw = (type_token[1] == '4');
-    color_type = PNG_COLOR_TYPE_GRAY;
-    bit_depth = 1;
-  }
-  else if ((type_token[1] == '2') || (type_token[1] == '5'))
-  {
-    raw = (type_token[1] == '5');
-    color_type = PNG_COLOR_TYPE_GRAY;
-    get_token(pnm_file, width_token);
-    sscanf (width_token, "%lu", &width);
-    get_token(pnm_file, height_token);
-    sscanf (height_token, "%lu", &height);
-    get_token(pnm_file, maxval_token);
-    sscanf (maxval_token, "%lu", &maxval);
-    if (maxval <= 1)
-      bit_depth = 1;
-    else if (maxval <= 3)
-      bit_depth = 2;
-    else if (maxval <= 15)
-      bit_depth = 4;
-    else if (maxval <= 255)
-      bit_depth = 8;
-    else /* if (maxval <= 65535) */
-      bit_depth = 16;
-  }
-  else if ((type_token[1] == '3') || (type_token[1] == '6'))
-  {
-    raw = (type_token[1] == '6');
-    color_type = PNG_COLOR_TYPE_RGB;
-    get_token(pnm_file, width_token);
-    sscanf (width_token, "%lu", &width);
-    get_token(pnm_file, height_token);
-    sscanf (height_token, "%lu", &height);
-    get_token(pnm_file, maxval_token);
-    sscanf (maxval_token, "%lu", &maxval);
-    if (maxval <= 1)
-      bit_depth = 1;
-    else if (maxval <= 3)
-      bit_depth = 2;
-    else if (maxval <= 15)
-      bit_depth = 4;
-    else if (maxval <= 255)
-      bit_depth = 8;
-    else /* if (maxval <= 65535) */
-      bit_depth = 16;
-  }
-  else
-  {
-    return FALSE;
-  }
-
-  /* read header of PGM file with alpha channel */
-
-  if (alpha)
-  {
-    if (color_type == PNG_COLOR_TYPE_GRAY)
-      color_type = PNG_COLOR_TYPE_GRAY_ALPHA;
-    if (color_type == PNG_COLOR_TYPE_RGB)
-      color_type = PNG_COLOR_TYPE_RGB_ALPHA;
-
-    get_token(alpha_file, type_token);
-    if (type_token[0] != 'P')
-    {
-      return FALSE;
-    }
-    else if ((type_token[1] == '2') || (type_token[1] == '5'))
-    {
-      alpha_raw = (type_token[1] == '5');
-      get_token(alpha_file, width_token);
-      sscanf (width_token, "%lu", &alpha_width);
-      if (alpha_width != width)
-        return FALSE;
-      get_token(alpha_file, height_token);
-      sscanf (height_token, "%lu", &alpha_height);
-      if (alpha_height != height)
-        return FALSE;
-      get_token(alpha_file, maxval_token);
-      sscanf (maxval_token, "%lu", &maxval);
-      if (maxval <= 1)
-        alpha_depth = 1;
-      else if (maxval <= 3)
-        alpha_depth = 2;
-      else if (maxval <= 15)
-        alpha_depth = 4;
-      else if (maxval <= 255)
-        alpha_depth = 8;
-      else /* if (maxval <= 65535) */
-        alpha_depth = 16;
-      if (alpha_depth != bit_depth)
-        return FALSE;
-    }
-    else
-    {
-      return FALSE;
-    }
-  } /* end if alpha */
-
-  /* calculate the number of channels and store alpha-presence */
-  if (color_type == PNG_COLOR_TYPE_GRAY)
-    channels = 1;
-  else if (color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
-    channels = 2;
-  else if (color_type == PNG_COLOR_TYPE_RGB)
-    channels = 3;
-  else if (color_type == PNG_COLOR_TYPE_RGB_ALPHA)
-    channels = 4;
-  else
-    channels = 0; /* should not happen */
-
-  alpha_present = (channels - 1) % 2;
-
-  /* row_bytes is the width x number of channels x (bit-depth / 8) */
-  row_bytes = width * channels * ((bit_depth <= 8) ? 1 : 2);
-
-  if ((png_pixels = (png_byte *) malloc (row_bytes * height * sizeof (png_byte))) == NULL)
-    return FALSE;
-
-  /* read data from PNM file */
-  pix_ptr = png_pixels;
-
-  for (row = 0; row < height; row++)
-  {
-    for (col = 0; col < width; col++)
-    {
-      for (i = 0; i < (channels - alpha_present); i++)
-      {
-        if (raw)
-          *pix_ptr++ = get_data (pnm_file, bit_depth);
-        else
-          if (bit_depth <= 8)
-            *pix_ptr++ = get_value (pnm_file, bit_depth);
-          else
-          {
-            tmp16 = get_value (pnm_file, bit_depth);
-            *pix_ptr = (png_byte) ((tmp16 >> 8) & 0xFF);
-            pix_ptr++;
-            *pix_ptr = (png_byte) (tmp16 & 0xFF);
-            pix_ptr++;
-          }
-      }
-
-      if (alpha) /* read alpha-channel from pgm file */
-      {
-        if (alpha_raw)
-          *pix_ptr++ = get_data (alpha_file, alpha_depth);
-        else
-          if (alpha_depth <= 8)
-            *pix_ptr++ = get_value (alpha_file, bit_depth);
-          else
-          {
-            tmp16 = get_value (alpha_file, bit_depth);
-            *pix_ptr++ = (png_byte) ((tmp16 >> 8) & 0xFF);
-            *pix_ptr++ = (png_byte) (tmp16 & 0xFF);
-          }
-      } /* if alpha */
-
-    } /* end for col */
-  } /* end for row */
-
-  /* prepare the standard PNG structures */
-  png_ptr = png_create_write_struct (PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
-  if (!png_ptr)
-  {
-    return FALSE;
-  }
-  info_ptr = png_create_info_struct (png_ptr);
-  if (!info_ptr)
-  {
-    png_destroy_write_struct (&png_ptr, (png_infopp) NULL);
-    return FALSE;
-  }
-
-  /* setjmp() must be called in every function that calls a PNG-reading libpng function */
-  if (setjmp (png_jmpbuf(png_ptr)))
-  {
-    png_destroy_write_struct (&png_ptr, (png_infopp) NULL);
-    return FALSE;
-  }
-
-  /* initialize the png structure */
-  png_init_io (png_ptr, png_file);
-
-  /* we're going to write more or less the same PNG as the input file */
-  png_set_IHDR (png_ptr, info_ptr, width, height, bit_depth, color_type,
-    (!interlace) ? PNG_INTERLACE_NONE : PNG_INTERLACE_ADAM7,
-    PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE);
-
-  /* write the file header information */
-  png_write_info (png_ptr, info_ptr);
-
-  /* if needed we will allocate memory for an new array of row-pointers */
-  if (row_pointers == (unsigned char**) NULL)
-  {
-    if ((row_pointers = (png_byte **) malloc (height * sizeof (png_bytep))) == NULL)
-    {
-      png_destroy_write_struct (&png_ptr, (png_infopp) NULL);
-      return FALSE;
-    }
-  }
-
-  /* set the individual row_pointers to point at the correct offsets */
-  for (i = 0; i < (height); i++)
-    row_pointers[i] = png_pixels + i * row_bytes;
-
-  /* write out the entire image data in one call */
-  png_write_image (png_ptr, row_pointers);
-
-  /* write the additional chuncks to the PNG file (not really needed) */
-  png_write_end (png_ptr, info_ptr);
-
-  /* clean up after the write, and free any memory allocated */
-  png_destroy_write_struct (&png_ptr, (png_infopp) NULL);
-
-  if (row_pointers != (unsigned char**) NULL)
-    free (row_pointers);
-  if (png_pixels != (unsigned char*) NULL)
-    free (png_pixels);
-
-  return TRUE;
-} /* end of pnm2png */
-
-/*
- * get_token() - gets the first string after whitespace
- */
-
-void get_token(FILE *pnm_file, char *token)
-{
-  int i = 0;
-
-  /* remove white-space */
-  do
-  {
-    token[i] = (unsigned char) fgetc (pnm_file);
-  }
-  while ((token[i] == '\n') || (token[i] == '\r') || (token[i] == ' '));
-
-  /* read string */
-  do
-  {
-    i++;
-    token[i] = (unsigned char) fgetc (pnm_file);
-  }
-  while ((token[i] != '\n') && (token[i] != '\r') && (token[i] != ' '));
-
-  token[i] = '\0';
-
-  return;
-}
-
-/*
- * get_data() - takes first byte and converts into next pixel value,
- *        taking as much bits as defined by bit-depth and
- *        using the bit-depth to fill up a byte (0Ah -> AAh)
- */
-
-png_uint_32 get_data (FILE *pnm_file, int depth)
-{
-  static int bits_left = 0;
-  static int old_value = 0;
-  static int mask = 0;
-  int i;
-  png_uint_32 ret_value;
-
-  if (mask == 0)
-    for (i = 0; i < depth; i++)
-      mask = (mask >> 1) | 0x80;
-
-  if (bits_left <= 0)
-  {
-    old_value = fgetc (pnm_file);
-    bits_left = 8;
-  }
-
-  ret_value = old_value & mask;
-  for (i = 1; i < (8 / depth); i++)
-    ret_value = ret_value || (ret_value >> depth);
-
-  old_value = (old_value << depth) & 0xFF;
-  bits_left -= depth;
-
-  return ret_value;
-}
-
-/*
- * get_value() - takes first (numeric) string and converts into number,
- *         using the bit-depth to fill up a byte (0Ah -> AAh)
- */
-
-png_uint_32 get_value (FILE *pnm_file, int depth)
-{
-  static png_uint_32 mask = 0;
-  png_byte token[16];
-  png_uint_32 ret_value;
-  int i = 0;
-
-  if (mask == 0)
-    for (i = 0; i < depth; i++)
-      mask = (mask << 1) | 0x01;
-
-  get_token (pnm_file, (char *) token);
-  sscanf ((const char *) token, "%lu", &ret_value);
-
-  ret_value &= mask;
-
-  if (depth < 8)
-    for (i = 0; i < (8 / depth); i++)
-      ret_value = (ret_value << depth) || ret_value;
-
-  return ret_value;
-}
-
-/* end of source */
-
diff --git a/contrib/pngminus/pnm2png.sh b/contrib/pngminus/pnm2png.sh
deleted file mode 100644
index d79df2f..0000000
--- a/contrib/pngminus/pnm2png.sh
+++ /dev/null
@@ -1,42 +0,0 @@
-#!/bin/sh
-# -- grayscale
-./pnm2png basn0g01.pgm basn0g01.png
-./pnm2png basn0g02.pgm basn0g02.png
-./pnm2png basn0g04.pgm basn0g04.png
-./pnm2png basn0g08.pgm basn0g08.png
-./pnm2png basn0g16.pgm basn0g16.png
-# -- full-color
-./pnm2png basn2c08.ppm basn2c08.png
-./pnm2png basn2c16.ppm basn2c16.png
-# -- palletted
-./pnm2png basn3p01.ppm basn3p01.png
-./pnm2png basn3p02.ppm basn3p02.png
-./pnm2png basn3p04.ppm basn3p04.png
-./pnm2png basn3p08.ppm basn3p08.png
-# -- gray with alpha-channel
-./pnm2png -alpha basn6a08.pgm basn4a08.pgm basn4a08.png
-./pnm2png -alpha basn6a16.pgm basn4a16.pgm basn4a16.png
-# -- color with alpha-channel
-./pnm2png -alpha basn6a08.pgm basn6a08.ppm basn6a08.png
-./pnm2png -alpha basn6a16.pgm basn6a16.ppm basn6a16.png
-# -- grayscale
-./pnm2png rawn0g01.pgm rawn0g01.png
-./pnm2png rawn0g02.pgm rawn0g02.png
-./pnm2png rawn0g04.pgm rawn0g04.png
-./pnm2png rawn0g08.pgm rawn0g08.png
-./pnm2png rawn0g16.pgm rawn0g16.png
-# -- full-color
-./pnm2png rawn2c08.ppm rawn2c08.png
-./pnm2png rawn2c16.ppm rawn2c16.png
-# -- palletted
-./pnm2png rawn3p01.ppm rawn3p01.png
-./pnm2png rawn3p02.ppm rawn3p02.png
-./pnm2png rawn3p04.ppm rawn3p04.png
-./pnm2png rawn3p08.ppm rawn3p08.png
-# -- gray with alpha-channel
-./pnm2png -alpha rawn6a08.pgm rawn4a08.pgm rawn4a08.png
-./pnm2png -alpha rawn6a16.pgm rawn4a16.pgm rawn4a16.png
-# -- color with alpha-channel
-./pnm2png -alpha rawn6a08.pgm rawn6a08.ppm rawn6a08.png
-./pnm2png -alpha rawn6a16.pgm rawn6a16.ppm rawn6a16.png
-
diff --git a/contrib/pngsuite/README b/contrib/pngsuite/README
deleted file mode 100644
index 714d12c..0000000
--- a/contrib/pngsuite/README
+++ /dev/null
@@ -1,85 +0,0 @@
-
-pngsuite
---------
-(c) Willem van Schaik, 1999
-
-Permission to use, copy, and distribute these images for any purpose and
-without fee is hereby granted.
-
-These 15 images are part of the much larger PngSuite test-set of 
-images, available for developers of PNG supporting software. The 
-complete set, available at http:/www.schaik.com/pngsuite/, contains 
-a variety of images to test interlacing, gamma settings, ancillary
-chunks, etc.
-
-The images in this directory represent the basic PNG color-types:
-grayscale (1-16 bit deep), full color (8 or 16 bit), paletted
-(1-8 bit) and grayscale or color images with alpha channel. You
-can use them to test the proper functioning of PNG software.
-
-    filename      depth type
-    ------------ ------ --------------
-    basn0g01.png  1-bit grayscale
-    basn0g02.png  2-bit grayscale
-    basn0g04.png  4-bit grayscale
-    basn0g08.png  8-bit grayscale
-    basn0g16.png 16-bit grayscale
-    basn2c08.png  8-bit truecolor
-    basn2c16.png 16-bit truecolor
-    basn3p01.png  1-bit paletted
-    basn3p02.png  2-bit paletted
-    basn3p04.png  4-bit paletted
-    basn3p08.png  8-bit paletted
-    basn4a08.png  8-bit gray with alpha
-    basn4a16.png 16-bit gray with alpha
-    basn6a08.png  8-bit RGBA
-    basn6a16.png 16-bit RGBA
-
-Here is the correct result of typing "pngtest -m *.png" in
-this directory:
-
-Testing basn0g01.png: PASS (524 zero samples)
- Filter 0 was used 32 times
-Testing basn0g02.png: PASS (448 zero samples)
- Filter 0 was used 32 times
-Testing basn0g04.png: PASS (520 zero samples)
- Filter 0 was used 32 times
-Testing basn0g08.png: PASS (3 zero samples)
- Filter 1 was used 9 times
- Filter 4 was used 23 times
-Testing basn0g16.png: PASS (1 zero samples)
- Filter 1 was used 1 times
- Filter 2 was used 31 times
-Testing basn2c08.png: PASS (6 zero samples)
- Filter 1 was used 5 times
- Filter 4 was used 27 times
-Testing basn2c16.png: PASS (592 zero samples)
- Filter 1 was used 1 times
- Filter 4 was used 31 times
-Testing basn3p01.png: PASS (512 zero samples)
- Filter 0 was used 32 times
-Testing basn3p02.png: PASS (448 zero samples)
- Filter 0 was used 32 times
-Testing basn3p04.png: PASS (544 zero samples)
- Filter 0 was used 32 times
-Testing basn3p08.png: PASS (4 zero samples)
- Filter 0 was used 32 times
-Testing basn4a08.png: PASS (32 zero samples)
- Filter 1 was used 1 times
- Filter 4 was used 31 times
-Testing basn4a16.png: PASS (64 zero samples)
- Filter 0 was used 1 times
- Filter 1 was used 2 times
- Filter 2 was used 1 times
- Filter 4 was used 28 times
-Testing basn6a08.png: PASS (160 zero samples)
- Filter 1 was used 1 times
- Filter 4 was used 31 times
-Testing basn6a16.png: PASS (1072 zero samples)
- Filter 1 was used 4 times
- Filter 4 was used 28 times
-libpng passes test
-
-Willem van Schaik
-<willem@schaik.com>
-October 1999
diff --git a/contrib/pngsuite/basn0g01.png b/contrib/pngsuite/basn0g01.png
deleted file mode 100644
index e31e1c7..0000000
--- a/contrib/pngsuite/basn0g01.png
+++ /dev/null
diff --git a/contrib/pngsuite/basn0g02.png b/contrib/pngsuite/basn0g02.png
deleted file mode 100644
index 68809dd..0000000
--- a/contrib/pngsuite/basn0g02.png
+++ /dev/null
diff --git a/contrib/pngsuite/basn0g04.png b/contrib/pngsuite/basn0g04.png
deleted file mode 100644
index 6fa089c..0000000
--- a/contrib/pngsuite/basn0g04.png
+++ /dev/null
diff --git a/contrib/pngsuite/basn0g08.png b/contrib/pngsuite/basn0g08.png
deleted file mode 100644
index bf522ee..0000000
--- a/contrib/pngsuite/basn0g08.png
+++ /dev/null
diff --git a/contrib/pngsuite/basn0g16.png b/contrib/pngsuite/basn0g16.png
deleted file mode 100644
index 318ebca..0000000
--- a/contrib/pngsuite/basn0g16.png
+++ /dev/null
diff --git a/contrib/pngsuite/basn2c08.png b/contrib/pngsuite/basn2c08.png
deleted file mode 100644
index 21d2f91..0000000
--- a/contrib/pngsuite/basn2c08.png
+++ /dev/null
diff --git a/contrib/pngsuite/basn2c16.png b/contrib/pngsuite/basn2c16.png
deleted file mode 100644
index 1bd4a4d..0000000
--- a/contrib/pngsuite/basn2c16.png
+++ /dev/null
diff --git a/contrib/pngsuite/basn3p01.png b/contrib/pngsuite/basn3p01.png
deleted file mode 100644
index a21db59..0000000
--- a/contrib/pngsuite/basn3p01.png
+++ /dev/null
diff --git a/contrib/pngsuite/basn3p02.png b/contrib/pngsuite/basn3p02.png
deleted file mode 100644
index 1d0ab61..0000000
--- a/contrib/pngsuite/basn3p02.png
+++ /dev/null
diff --git a/contrib/pngsuite/basn3p04.png b/contrib/pngsuite/basn3p04.png
deleted file mode 100644
index 6dc6eac..0000000
--- a/contrib/pngsuite/basn3p04.png
+++ /dev/null
diff --git a/contrib/pngsuite/basn3p08.png b/contrib/pngsuite/basn3p08.png
deleted file mode 100644
index 0e07f48..0000000
--- a/contrib/pngsuite/basn3p08.png
+++ /dev/null
diff --git a/contrib/pngsuite/basn4a08.png b/contrib/pngsuite/basn4a08.png
deleted file mode 100644
index 3bb0dd0..0000000
--- a/contrib/pngsuite/basn4a08.png
+++ /dev/null
diff --git a/contrib/pngsuite/basn4a16.png b/contrib/pngsuite/basn4a16.png
deleted file mode 100644
index 6dbee9f..0000000
--- a/contrib/pngsuite/basn4a16.png
+++ /dev/null
diff --git a/contrib/pngsuite/basn6a08.png b/contrib/pngsuite/basn6a08.png
deleted file mode 100644
index 6106230..0000000
--- a/contrib/pngsuite/basn6a08.png
+++ /dev/null
diff --git a/contrib/pngsuite/basn6a16.png b/contrib/pngsuite/basn6a16.png
deleted file mode 100644
index a9bf3cb..0000000
--- a/contrib/pngsuite/basn6a16.png
+++ /dev/null
diff --git a/contrib/visupng/PngFile.c b/contrib/visupng/PngFile.c
deleted file mode 100644
index 959afe9..0000000
--- a/contrib/visupng/PngFile.c
+++ /dev/null
@@ -1,439 +0,0 @@
-//-------------------------------------
-//  PNGFILE.C -- Image File Functions
-//-------------------------------------
-
-// Copyright 2000, Willem van Schaik.  For conditions of distribution and
-// use, see the copyright/license/disclaimer notice in png.h
-
-#include <windows.h>
-#include <commdlg.h>
-#include <stdio.h>
-#include <stdlib.h>
-
-#include "png.h"
-#include "pngfile.h"
-#include "cexcept.h"
-
-define_exception_type(const char *);
-extern struct exception_context the_exception_context[1];
-struct exception_context the_exception_context[1];
-png_const_charp msg;
-
-static OPENFILENAME ofn;
-
-static png_structp png_ptr = NULL;
-static png_infop info_ptr = NULL;
-
-
-// cexcept interface
-
-static void
-png_cexcept_error(png_structp png_ptr, png_const_charp msg)
-{
-   if(png_ptr)
-     ;
-#ifndef PNG_NO_CONSOLE_IO
-   fprintf(stderr, "libpng error: %s\n", msg);
-#endif
-   {
-      Throw msg;
-   }
-}
-
-// Windows open-file functions
-
-void PngFileInitialize (HWND hwnd)
-{
-    static TCHAR szFilter[] = TEXT ("PNG Files (*.PNG)\0*.png\0")
-        TEXT ("All Files (*.*)\0*.*\0\0");
-
-    ofn.lStructSize       = sizeof (OPENFILENAME);
-    ofn.hwndOwner         = hwnd;
-    ofn.hInstance         = NULL;
-    ofn.lpstrFilter       = szFilter;
-    ofn.lpstrCustomFilter = NULL;
-    ofn.nMaxCustFilter    = 0;
-    ofn.nFilterIndex      = 0;
-    ofn.lpstrFile         = NULL;          // Set in Open and Close functions
-    ofn.nMaxFile          = MAX_PATH;
-    ofn.lpstrFileTitle    = NULL;          // Set in Open and Close functions
-    ofn.nMaxFileTitle     = MAX_PATH;
-    ofn.lpstrInitialDir   = NULL;
-    ofn.lpstrTitle        = NULL;
-    ofn.Flags             = 0;             // Set in Open and Close functions
-    ofn.nFileOffset       = 0;
-    ofn.nFileExtension    = 0;
-    ofn.lpstrDefExt       = TEXT ("png");
-    ofn.lCustData         = 0;
-    ofn.lpfnHook          = NULL;
-    ofn.lpTemplateName    = NULL;
-}
-
-BOOL PngFileOpenDlg (HWND hwnd, PTSTR pstrFileName, PTSTR pstrTitleName)
-{
-    ofn.hwndOwner         = hwnd;
-    ofn.lpstrFile         = pstrFileName;
-    ofn.lpstrFileTitle    = pstrTitleName;
-    ofn.Flags             = OFN_HIDEREADONLY;
-
-    return GetOpenFileName (&ofn);
-}
-
-BOOL PngFileSaveDlg (HWND hwnd, PTSTR pstrFileName, PTSTR pstrTitleName)
-{
-    ofn.hwndOwner         = hwnd;
-    ofn.lpstrFile         = pstrFileName;
-    ofn.lpstrFileTitle    = pstrTitleName;
-    ofn.Flags             = OFN_HIDEREADONLY | OFN_OVERWRITEPROMPT;
-
-    return GetSaveFileName (&ofn);
-}
-
-// PNG image handler functions
-
-BOOL PngLoadImage (PTSTR pstrFileName, png_byte **ppbImageData,
-                   int *piWidth, int *piHeight, int *piChannels, png_color *pBkgColor)
-{
-    static FILE        *pfFile;
-    png_byte            pbSig[8];
-    int                 iBitDepth;
-    int                 iColorType;
-    double              dGamma;
-    png_color_16       *pBackground;
-    png_uint_32         ulChannels;
-    png_uint_32         ulRowBytes;
-    png_byte           *pbImageData = *ppbImageData;
-    static png_byte   **ppbRowPointers = NULL;
-    int                 i;
-
-    // open the PNG input file
-
-    if (!pstrFileName)
-    {
-        *ppbImageData = pbImageData = NULL;
-        return FALSE;
-    }
-
-    if (!(pfFile = fopen(pstrFileName, "rb")))
-    {
-        *ppbImageData = pbImageData = NULL;
-        return FALSE;
-    }
-
-    // first check the eight byte PNG signature
-
-    fread(pbSig, 1, 8, pfFile);
-    if (!png_check_sig(pbSig, 8))
-    {
-        *ppbImageData = pbImageData = NULL;
-        return FALSE;
-    }
-
-    // create the two png(-info) structures
-
-    png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL,
-      (png_error_ptr)png_cexcept_error, (png_error_ptr)NULL);
-    if (!png_ptr)
-    {
-        *ppbImageData = pbImageData = NULL;
-        return FALSE;
-    }
-
-    info_ptr = png_create_info_struct(png_ptr);
-    if (!info_ptr)
-    {
-        png_destroy_read_struct(&png_ptr, NULL, NULL);
-        *ppbImageData = pbImageData = NULL;
-        return FALSE;
-    }
-
-    Try
-    {
-        
-        // initialize the png structure
-        
-#if !defined(PNG_NO_STDIO)
-        png_init_io(png_ptr, pfFile);
-#else
-        png_set_read_fn(png_ptr, (png_voidp)pfFile, png_read_data);
-#endif
-        
-        png_set_sig_bytes(png_ptr, 8);
-        
-        // read all PNG info up to image data
-        
-        png_read_info(png_ptr, info_ptr);
-        
-        // get width, height, bit-depth and color-type
-        
-        png_get_IHDR(png_ptr, info_ptr, piWidth, piHeight, &iBitDepth,
-            &iColorType, NULL, NULL, NULL);
-        
-        // expand images of all color-type and bit-depth to 3x8 bit RGB images
-        // let the library process things like alpha, transparency, background
-        
-        if (iBitDepth == 16)
-            png_set_strip_16(png_ptr);
-        if (iColorType == PNG_COLOR_TYPE_PALETTE)
-            png_set_expand(png_ptr);
-        if (iBitDepth < 8)
-            png_set_expand(png_ptr);
-        if (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS))
-            png_set_expand(png_ptr);
-        if (iColorType == PNG_COLOR_TYPE_GRAY ||
-            iColorType == PNG_COLOR_TYPE_GRAY_ALPHA)
-            png_set_gray_to_rgb(png_ptr);
-        
-        // set the background color to draw transparent and alpha images over.
-        if (png_get_bKGD(png_ptr, info_ptr, &pBackground))
-        {
-            png_set_background(png_ptr, pBackground, PNG_BACKGROUND_GAMMA_FILE, 1, 1.0);
-            pBkgColor->red   = (byte) pBackground->red;
-            pBkgColor->green = (byte) pBackground->green;
-            pBkgColor->blue  = (byte) pBackground->blue;
-        }
-        else
-        {
-            pBkgColor = NULL;
-        }
-        
-        // if required set gamma conversion
-        if (png_get_gAMA(png_ptr, info_ptr, &dGamma))
-            png_set_gamma(png_ptr, (double) 2.2, dGamma);
-        
-        // after the transformations have been registered update info_ptr data
-        
-        png_read_update_info(png_ptr, info_ptr);
-        
-        // get again width, height and the new bit-depth and color-type
-        
-        png_get_IHDR(png_ptr, info_ptr, piWidth, piHeight, &iBitDepth,
-            &iColorType, NULL, NULL, NULL);
-        
-        
-        // row_bytes is the width x number of channels
-        
-        ulRowBytes = png_get_rowbytes(png_ptr, info_ptr);
-        ulChannels = png_get_channels(png_ptr, info_ptr);
-        
-        *piChannels = ulChannels;
-        
-        // now we can allocate memory to store the image
-        
-        if (pbImageData)
-        {
-            free (pbImageData);
-            pbImageData = NULL;
-        }
-        if ((pbImageData = (png_byte *) malloc(ulRowBytes * (*piHeight)
-                            * sizeof(png_byte))) == NULL)
-        {
-            png_error(png_ptr, "Visual PNG: out of memory");
-        }
-        *ppbImageData = pbImageData;
-        
-        // and allocate memory for an array of row-pointers
-        
-        if ((ppbRowPointers = (png_bytepp) malloc((*piHeight)
-                            * sizeof(png_bytep))) == NULL)
-        {
-            png_error(png_ptr, "Visual PNG: out of memory");
-        }
-        
-        // set the individual row-pointers to point at the correct offsets
-        
-        for (i = 0; i < (*piHeight); i++)
-            ppbRowPointers[i] = pbImageData + i * ulRowBytes;
-        
-        // now we can go ahead and just read the whole image
-        
-        png_read_image(png_ptr, ppbRowPointers);
-        
-        // read the additional chunks in the PNG file (not really needed)
-        
-        png_read_end(png_ptr, NULL);
-        
-        // and we're done
-        
-        free (ppbRowPointers);
-        ppbRowPointers = NULL;
-        
-        // yepp, done
-    }
-
-    Catch (msg)
-    {
-        png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
-
-        *ppbImageData = pbImageData = NULL;
-        
-        if(ppbRowPointers)
-            free (ppbRowPointers);
-
-        fclose(pfFile);
-
-        return FALSE;
-    }
-
-    fclose (pfFile);
-
-    return TRUE;
-}
-
-
-BOOL PngSaveImage (PTSTR pstrFileName, png_byte *pDiData,
-                   int iWidth, int iHeight, png_color bkgColor)
-{
-    const int           ciBitDepth = 8;
-    const int           ciChannels = 3;
-
-    static FILE        *pfFile;
-    png_uint_32         ulRowBytes;
-    static png_byte   **ppbRowPointers = NULL;
-    int                 i;
-
-    // open the PNG output file
-
-    if (!pstrFileName)
-        return FALSE;
-
-    if (!(pfFile = fopen(pstrFileName, "wb")))
-        return FALSE;
-
-    // prepare the standard PNG structures
-
-    png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL,
-      (png_error_ptr)png_cexcept_error, (png_error_ptr)NULL);
-    if (!png_ptr)
-    {
-        fclose(pfFile);
-        return FALSE;
-    }
-
-    info_ptr = png_create_info_struct(png_ptr);
-    if (!info_ptr) {
-        fclose(pfFile);
-        png_destroy_write_struct(&png_ptr, (png_infopp) NULL);
-        return FALSE;
-    }
-
-    Try
-    {
-        // initialize the png structure
-        
-#if !defined(PNG_NO_STDIO)
-        png_init_io(png_ptr, pfFile);
-#else
-        png_set_write_fn(png_ptr, (png_voidp)pfFile, png_write_data, png_flush);
-#endif
-        
-        // we're going to write a very simple 3x8 bit RGB image
-        
-        png_set_IHDR(png_ptr, info_ptr, iWidth, iHeight, ciBitDepth,
-            PNG_COLOR_TYPE_RGB, PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_BASE,
-            PNG_FILTER_TYPE_BASE);
-        
-        // write the file header information
-        
-        png_write_info(png_ptr, info_ptr);
-        
-        // swap the BGR pixels in the DiData structure to RGB
-        
-        png_set_bgr(png_ptr);
-        
-        // row_bytes is the width x number of channels
-        
-        ulRowBytes = iWidth * ciChannels;
-        
-        // we can allocate memory for an array of row-pointers
-        
-        if ((ppbRowPointers = (png_bytepp) malloc(iHeight * sizeof(png_bytep))) == NULL)
-            Throw "Visualpng: Out of memory";
-        
-        // set the individual row-pointers to point at the correct offsets
-        
-        for (i = 0; i < iHeight; i++)
-            ppbRowPointers[i] = pDiData + i * (((ulRowBytes + 3) >> 2) << 2);
-        
-        // write out the entire image data in one call
-        
-        png_write_image (png_ptr, ppbRowPointers);
-        
-        // write the additional chunks to the PNG file (not really needed)
-        
-        png_write_end(png_ptr, info_ptr);
-        
-        // and we're done
-        
-        free (ppbRowPointers);
-        ppbRowPointers = NULL;
-        
-        // clean up after the write, and free any memory allocated
-        
-        png_destroy_write_struct(&png_ptr, (png_infopp) NULL);
-        
-        // yepp, done
-    }
-
-    Catch (msg)
-    {
-        png_destroy_write_struct(&png_ptr, (png_infopp) NULL);
-
-        if(ppbRowPointers)
-            free (ppbRowPointers);
-
-        fclose(pfFile);
-
-        return FALSE;
-    }
-    
-    fclose (pfFile);
-    
-    return TRUE;
-}
-
-#ifdef PNG_NO_STDIO
-
-static void
-png_read_data(png_structp png_ptr, png_bytep data, png_size_t length)
-{
-   png_size_t check;
-
-   /* fread() returns 0 on error, so it is OK to store this in a png_size_t
-    * instead of an int, which is what fread() actually returns.
-    */
-   check = (png_size_t)fread(data, (png_size_t)1, length,
-      (FILE *)png_ptr->io_ptr);
-
-   if (check != length)
-   {
-      png_error(png_ptr, "Read Error");
-   }
-}
-
-static void
-png_write_data(png_structp png_ptr, png_bytep data, png_size_t length)
-{
-   png_uint_32 check;
-
-   check = fwrite(data, 1, length, (FILE *)(png_ptr->io_ptr));
-   if (check != length)
-   {
-      png_error(png_ptr, "Write Error");
-   }
-}
-
-static void
-png_flush(png_structp png_ptr)
-{
-   FILE *io_ptr;
-   io_ptr = (FILE *)CVT_PTR((png_ptr->io_ptr));
-   if (io_ptr != NULL)
-      fflush(io_ptr);
-}
-
-#endif
-
-//-----------------
-//  end of source
-//-----------------
diff --git a/contrib/visupng/PngFile.h b/contrib/visupng/PngFile.h
deleted file mode 100644
index a900fd4..0000000
--- a/contrib/visupng/PngFile.h
+++ /dev/null
@@ -1,27 +0,0 @@
-//------------------------------------------
-//  PNGFILE.H -- Header File for pngfile.c
-//------------------------------------------
-
-// Copyright 2000, Willem van Schaik.  For conditions of distribution and
-// use, see the copyright/license/disclaimer notice in png.h
-
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <windows.h>
-
-void PngFileInitialize (HWND hwnd) ;
-BOOL PngFileOpenDlg (HWND hwnd, PTSTR pstrFileName, PTSTR pstrTitleName) ;
-BOOL PngFileSaveDlg (HWND hwnd, PTSTR pstrFileName, PTSTR pstrTitleName) ;
-
-BOOL PngLoadImage (PTSTR pstrFileName, png_byte **ppbImageData, 
-                   int *piWidth, int *piHeight, int *piChannels, png_color *pBkgColor);
-BOOL PngSaveImage (PTSTR pstrFileName, png_byte *pDiData,
-                   int iWidth, int iHeight, png_color BkgColor);
-
-#if defined(PNG_NO_STDIO)
-static void png_read_data(png_structp png_ptr, png_bytep data, png_size_t length);
-static void png_write_data(png_structp png_ptr, png_bytep data, png_size_t length);
-static void png_flush(png_structp png_ptr);
-#endif
-
diff --git a/contrib/visupng/README.txt b/contrib/visupng/README.txt
deleted file mode 100644
index 4a753d8..0000000
--- a/contrib/visupng/README.txt
+++ /dev/null
@@ -1,58 +0,0 @@
-Microsoft Developer Studio Build File, Format Version 6.00 for VisualPng
-------------------------------------------------------------------------
-
-Copyright 2000, Willem van Schaik.  For conditions of distribution and
-use, see the copyright/license/disclaimer notice in png.h
-
-As a PNG .dll demo VisualPng is finished. More features would only hinder
-the program's objective. However, further extensions (like support for other 
-graphics formats) are in development. To get these, or for pre-compiled 
-binaries, go to "http://www.schaik.com/png/visualpng.html".
-
-------------------------------------------------------------------------
-
-Assumes that
-
-   libpng DLLs and LIBs are in ..\..\projects\msvc\win32\libpng
-   zlib DLLs and LIBs are in   ..\..\projects\msvc\win32\zlib
-   libpng header files are in  ..\..\..\libpng
-   zlib header files are in    ..\..\..\zlib
-   the pngsuite images are in  ..\pngsuite
-
-To build:
-
-1) On the main menu Select "Build|Set Active configuration".
-   Choose the configuration that corresponds to the library you want to test.
-   This library must have been built using the libpng MS project located in
-   the "..\..\mscv" subdirectory.
-
-2) Select "Build|Clean"
-
-3) Select "Build|Rebuild All"
-
-4) After compiling and linking VisualPng will be started to view an image
-   from the PngSuite directory.  Press Ctrl-N (and Ctrl-V) for other images.
-
-
-To install:
-
-When distributing VisualPng (or a further development) the following options
-are available:
-
-1) Build the program with the configuration "Win32 LIB" and you only need to
-   include the executable from the ./lib directory in your distribution.
-
-2) Build the program with the configuration "Win32 DLL" and you need to put
-   in your distribution the executable from the ./dll directory and the dll's
-   libpng1.dll, zlib.dll and msvcrt.dll.  These need to be in the user's PATH.
-
-
-Willem van Schaik
-Calgary, June 6th 2000
-
-P.S. VisualPng was written based on preliminary work of:
-
-    - Simon-Pierre Cadieux
-    - Glenn Randers-Pehrson
-    - Greg Roelofs
-
diff --git a/contrib/visupng/VisualPng.c b/contrib/visupng/VisualPng.c
deleted file mode 100644
index f2cf6ee..0000000
--- a/contrib/visupng/VisualPng.c
+++ /dev/null
@@ -1,961 +0,0 @@
-//------------------------------------
-//  VisualPng.C -- Shows a PNG image
-//------------------------------------
-
-// Copyright 2000, Willem van Schaik.  For conditions of distribution and
-// use, see the copyright/license/disclaimer notice in png.h
-
-// switches
-
-// defines
-
-#define PROGNAME  "VisualPng"
-#define LONGNAME  "Win32 Viewer for PNG-files"
-#define VERSION   "1.0 of 2000 June 07"
-
-// constants
-
-#define MARGIN 8
-
-// standard includes
-
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <windows.h>
-
-// application includes
-
-#include "png.h"
-#include "pngfile.h"
-#include "resource.h"
-
-// macros
-
-// function prototypes
-
-LRESULT CALLBACK WndProc (HWND, UINT, WPARAM, LPARAM);
-BOOL    CALLBACK AboutDlgProc (HWND, UINT, WPARAM, LPARAM) ;
-
-BOOL CenterAbout (HWND hwndChild, HWND hwndParent);
-
-BOOL BuildPngList (PTSTR pstrPathName, TCHAR **ppFileList, int *pFileCount,
-        int *pFileIndex);
-
-BOOL SearchPngList (TCHAR *pFileList, int FileCount, int *pFileIndex,
-        PTSTR pstrPrevName, PTSTR pstrNextName);
-
-BOOL LoadImageFile(HWND hwnd, PTSTR pstrPathName,
-        png_byte **ppbImage, int *pxImgSize, int *pyImgSize, int *piChannels,
-        png_color *pBkgColor);
-
-BOOL DisplayImage (HWND hwnd, BYTE **ppDib,
-        BYTE **ppDiData, int cxWinSize, int cyWinSize,
-        BYTE *pbImage, int cxImgSize, int cyImgSize, int cImgChannels,
-        BOOL bStretched);
-
-BOOL InitBitmap (
-        BYTE *pDiData, int cxWinSize, int cyWinSize);
-
-BOOL FillBitmap (
-        BYTE *pDiData, int cxWinSize, int cyWinSize,
-        BYTE *pbImage, int cxImgSize, int cyImgSize, int cImgChannels,
-        BOOL bStretched);
-
-// a few global variables
-
-static char *szProgName = PROGNAME;
-static char *szAppName = LONGNAME;
-static char *szIconName = PROGNAME;
-static char szCmdFileName [MAX_PATH];
-
-// MAIN routine
-
-int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance,
-                    PSTR szCmdLine, int iCmdShow)
-{
-    HACCEL   hAccel;
-    HWND     hwnd;
-    MSG      msg;
-    WNDCLASS wndclass;
-    int ixBorders, iyBorders;
-
-    wndclass.style         = CS_HREDRAW | CS_VREDRAW;
-    wndclass.lpfnWndProc   = WndProc;
-    wndclass.cbClsExtra    = 0;
-    wndclass.cbWndExtra    = 0;
-    wndclass.hInstance     = hInstance;
-    wndclass.hIcon         = LoadIcon (hInstance, szIconName) ;
-    wndclass.hCursor       = LoadCursor (NULL, IDC_ARROW);
-    wndclass.hbrBackground = NULL; // (HBRUSH) GetStockObject (GRAY_BRUSH);
-    wndclass.lpszMenuName  = szProgName;
-    wndclass.lpszClassName = szProgName;
-
-    if (!RegisterClass (&wndclass))
-    {
-        MessageBox (NULL, TEXT ("Error: this program requires Windows NT!"),
-            szProgName, MB_ICONERROR);
-        return 0;
-    }
-
-    // if filename given on commandline, store it
-    if ((szCmdLine != NULL) && (*szCmdLine != '\0'))
-        if (szCmdLine[0] == '"')
-            strncpy (szCmdFileName, szCmdLine + 1, strlen(szCmdLine) - 2);
-        else
-            strcpy (szCmdFileName, szCmdLine);
-    else
-        strcpy (szCmdFileName, "");
-
-    // calculate size of window-borders
-    ixBorders = 2 * (GetSystemMetrics (SM_CXBORDER) +
-                     GetSystemMetrics (SM_CXDLGFRAME));
-    iyBorders = 2 * (GetSystemMetrics (SM_CYBORDER) +
-                     GetSystemMetrics (SM_CYDLGFRAME)) +
-                     GetSystemMetrics (SM_CYCAPTION) +
-                     GetSystemMetrics (SM_CYMENUSIZE) +
-                     1; /* WvS: don't ask me why? */
-
-    hwnd = CreateWindow (szProgName, szAppName,
-        WS_OVERLAPPEDWINDOW,
-        CW_USEDEFAULT, CW_USEDEFAULT,
-        512 + 2 * MARGIN + ixBorders, 384 + 2 * MARGIN + iyBorders,
-//      CW_USEDEFAULT, CW_USEDEFAULT,
-        NULL, NULL, hInstance, NULL);
-
-    ShowWindow (hwnd, iCmdShow);
-    UpdateWindow (hwnd);
-
-    hAccel = LoadAccelerators (hInstance, szProgName);
-
-    while (GetMessage (&msg, NULL, 0, 0))
-    {
-        if (!TranslateAccelerator (hwnd, hAccel, &msg))
-        {
-            TranslateMessage (&msg);
-            DispatchMessage (&msg);
-        }
-    }
-    return msg.wParam;
-}
-
-LRESULT CALLBACK WndProc (HWND hwnd, UINT message, WPARAM wParam,
-        LPARAM lParam)
-{
-    static HINSTANCE          hInstance ;
-    static HDC                hdc;
-    static PAINTSTRUCT        ps;
-    static HMENU              hMenu;
-
-    static BITMAPFILEHEADER  *pbmfh;
-    static BITMAPINFOHEADER  *pbmih;
-    static BYTE              *pbImage;
-    static int                cxWinSize, cyWinSize;
-    static int                cxImgSize, cyImgSize;
-    static int                cImgChannels;
-    static png_color          bkgColor = {127, 127, 127};
-
-    static BOOL               bStretched = TRUE;
-
-    static BYTE              *pDib = NULL;
-    static BYTE              *pDiData = NULL;
-
-    static TCHAR              szImgPathName [MAX_PATH];
-    static TCHAR              szTitleName [MAX_PATH];
-
-    static TCHAR             *pPngFileList = NULL;
-    static int                iPngFileCount;
-    static int                iPngFileIndex;
-
-    BOOL                      bOk;
-
-    switch (message)
-    {
-    case WM_CREATE:
-        hInstance = ((LPCREATESTRUCT) lParam)->hInstance ;
-        PngFileInitialize (hwnd);
-
-        strcpy (szImgPathName, "");
-
-        // in case we process file given on command-line
-
-        if (szCmdFileName[0] != '\0')
-        {
-            strcpy (szImgPathName, szCmdFileName);
-
-            // read the other png-files in the directory for later
-            // next/previous commands
-
-            BuildPngList (szImgPathName, &pPngFileList, &iPngFileCount,
-                          &iPngFileIndex);
-
-            // load the image from file
-
-            if (!LoadImageFile (hwnd, szImgPathName,
-                &pbImage, &cxImgSize, &cyImgSize, &cImgChannels, &bkgColor))
-                return 0;
-
-            // invalidate the client area for later update
-
-            InvalidateRect (hwnd, NULL, TRUE);
-
-            // display the PNG into the DIBitmap
-
-            DisplayImage (hwnd, &pDib, &pDiData, cxWinSize, cyWinSize,
-                pbImage, cxImgSize, cyImgSize, cImgChannels, bStretched);
-        }
-
-        return 0;
-
-    case WM_SIZE:
-        cxWinSize = LOWORD (lParam);
-        cyWinSize = HIWORD (lParam);
-
-        // invalidate the client area for later update
-
-        InvalidateRect (hwnd, NULL, TRUE);
-
-        // display the PNG into the DIBitmap
-
-        DisplayImage (hwnd, &pDib, &pDiData, cxWinSize, cyWinSize,
-            pbImage, cxImgSize, cyImgSize, cImgChannels, bStretched);
-
-        return 0;
-
-    case WM_INITMENUPOPUP:
-        hMenu = GetMenu (hwnd);
-
-        if (pbImage)
-            EnableMenuItem (hMenu, IDM_FILE_SAVE, MF_ENABLED);
-        else
-            EnableMenuItem (hMenu, IDM_FILE_SAVE, MF_GRAYED);
-
-        return 0;
-
-    case WM_COMMAND:
-        hMenu = GetMenu (hwnd);
-
-        switch (LOWORD (wParam))
-        {
-        case IDM_FILE_OPEN:
-
-            // show the File Open dialog box
-
-            if (!PngFileOpenDlg (hwnd, szImgPathName, szTitleName))
-                return 0;
-
-            // read the other png-files in the directory for later
-            // next/previous commands
-
-            BuildPngList (szImgPathName, &pPngFileList, &iPngFileCount,
-                          &iPngFileIndex);
-
-            // load the image from file
-
-            if (!LoadImageFile (hwnd, szImgPathName,
-                &pbImage, &cxImgSize, &cyImgSize, &cImgChannels, &bkgColor))
-                return 0;
-
-            // invalidate the client area for later update
-
-            InvalidateRect (hwnd, NULL, TRUE);
-
-            // display the PNG into the DIBitmap
-
-            DisplayImage (hwnd, &pDib, &pDiData, cxWinSize, cyWinSize,
-                pbImage, cxImgSize, cyImgSize, cImgChannels, bStretched);
-
-            return 0;
-
-        case IDM_FILE_SAVE:
-
-            // show the File Save dialog box
-
-            if (!PngFileSaveDlg (hwnd, szImgPathName, szTitleName))
-                return 0;
-
-            // save the PNG to a disk file
-
-            SetCursor (LoadCursor (NULL, IDC_WAIT));
-            ShowCursor (TRUE);
-
-            bOk = PngSaveImage (szImgPathName, pDiData, cxWinSize, cyWinSize,
-                  bkgColor);
-
-            ShowCursor (FALSE);
-            SetCursor (LoadCursor (NULL, IDC_ARROW));
-
-            if (!bOk)
-                MessageBox (hwnd, TEXT ("Error in saving the PNG image"),
-                szProgName, MB_ICONEXCLAMATION | MB_OK);
-            return 0;
-
-        case IDM_FILE_NEXT:
-
-            // read next entry in the directory
-
-            if (SearchPngList (pPngFileList, iPngFileCount, &iPngFileIndex,
-                NULL, szImgPathName))
-            {
-                if (strcmp (szImgPathName, "") == 0)
-                    return 0;
-                
-                // load the image from file
-                
-                if (!LoadImageFile (hwnd, szImgPathName, &pbImage,
-                        &cxImgSize, &cyImgSize, &cImgChannels, &bkgColor))
-                    return 0;
-                
-                // invalidate the client area for later update
-                
-                InvalidateRect (hwnd, NULL, TRUE);
-                
-                // display the PNG into the DIBitmap
-                
-                DisplayImage (hwnd, &pDib, &pDiData, cxWinSize, cyWinSize,
-                    pbImage, cxImgSize, cyImgSize, cImgChannels, bStretched);
-            }
-            
-            return 0;
-
-        case IDM_FILE_PREVIOUS:
-
-            // read previous entry in the directory
-
-            if (SearchPngList (pPngFileList, iPngFileCount, &iPngFileIndex,
-                szImgPathName, NULL))
-            {
-                
-                if (strcmp (szImgPathName, "") == 0)
-                    return 0;
-                
-                // load the image from file
-                
-                if (!LoadImageFile (hwnd, szImgPathName, &pbImage, &cxImgSize,
-                    &cyImgSize, &cImgChannels, &bkgColor))
-                    return 0;
-                
-                // invalidate the client area for later update
-                
-                InvalidateRect (hwnd, NULL, TRUE);
-                
-                // display the PNG into the DIBitmap
-                
-                DisplayImage (hwnd, &pDib, &pDiData, cxWinSize, cyWinSize,
-                    pbImage, cxImgSize, cyImgSize, cImgChannels, bStretched);
-            }
-
-            return 0;
-
-        case IDM_FILE_EXIT:
-
-            // more cleanup needed...
-
-            // free image buffer
-
-            if (pDib != NULL)
-            {
-                free (pDib);
-                pDib = NULL;
-            }
-
-            // free file-list
-
-            if (pPngFileList != NULL)
-            {
-                free (pPngFileList);
-                pPngFileList = NULL;
-            }
-
-            // let's go ...
-
-            exit (0);
-
-            return 0;
-
-        case IDM_OPTIONS_STRETCH:
-            bStretched = !bStretched;
-            if (bStretched)
-                CheckMenuItem (hMenu, IDM_OPTIONS_STRETCH, MF_CHECKED);
-            else
-                CheckMenuItem (hMenu, IDM_OPTIONS_STRETCH, MF_UNCHECKED);
-
-            // invalidate the client area for later update
-
-            InvalidateRect (hwnd, NULL, TRUE);
-
-            // display the PNG into the DIBitmap
-
-            DisplayImage (hwnd, &pDib, &pDiData, cxWinSize, cyWinSize,
-                pbImage, cxImgSize, cyImgSize, cImgChannels, bStretched);
-
-            return 0;
-
-        case IDM_HELP_ABOUT:
-            DialogBox (hInstance, TEXT ("AboutBox"), hwnd, AboutDlgProc) ;
-            return 0;
-
-        } // end switch
-
-        break;
-
-    case WM_PAINT:
-        hdc = BeginPaint (hwnd, &ps);
-
-        if (pDib)
-            SetDIBitsToDevice (hdc, 0, 0, cxWinSize, cyWinSize, 0, 0,
-                0, cyWinSize, pDiData, (BITMAPINFO *) pDib, DIB_RGB_COLORS);
-
-        EndPaint (hwnd, &ps);
-        return 0;
-
-    case WM_DESTROY:
-        if (pbmfh)
-        {
-            free (pbmfh);
-            pbmfh = NULL;
-        }
-
-        PostQuitMessage (0);
-        return 0;
-    }
-
-    return DefWindowProc (hwnd, message, wParam, lParam);
-}
-
-BOOL CALLBACK AboutDlgProc (HWND hDlg, UINT message,
-                            WPARAM wParam, LPARAM lParam)
-{
-     switch (message)
-     {
-     case WM_INITDIALOG :
-          ShowWindow (hDlg, SW_HIDE);
-          CenterAbout (hDlg, GetWindow (hDlg, GW_OWNER));
-          ShowWindow (hDlg, SW_SHOW);
-          return TRUE ;
-
-     case WM_COMMAND :
-          switch (LOWORD (wParam))
-          {
-          case IDOK :
-          case IDCANCEL :
-               EndDialog (hDlg, 0) ;
-               return TRUE ;
-          }
-          break ;
-     }
-     return FALSE ;
-}
-
-//---------------
-//  CenterAbout
-//---------------
-
-BOOL CenterAbout (HWND hwndChild, HWND hwndParent)
-{
-   RECT    rChild, rParent, rWorkArea;
-   int     wChild, hChild, wParent, hParent;
-   int     xNew, yNew;
-   BOOL  bResult;
-
-   // Get the Height and Width of the child window
-   GetWindowRect (hwndChild, &rChild);
-   wChild = rChild.right - rChild.left;
-   hChild = rChild.bottom - rChild.top;
-
-   // Get the Height and Width of the parent window
-   GetWindowRect (hwndParent, &rParent);
-   wParent = rParent.right - rParent.left;
-   hParent = rParent.bottom - rParent.top;
-
-   // Get the limits of the 'workarea'
-   bResult = SystemParametersInfo(
-      SPI_GETWORKAREA,  // system parameter to query or set
-      sizeof(RECT),
-      &rWorkArea,
-      0);
-   if (!bResult) {
-      rWorkArea.left = rWorkArea.top = 0;
-      rWorkArea.right = GetSystemMetrics(SM_CXSCREEN);
-      rWorkArea.bottom = GetSystemMetrics(SM_CYSCREEN);
-   }
-
-   // Calculate new X position, then adjust for workarea
-   xNew = rParent.left + ((wParent - wChild) /2);
-   if (xNew < rWorkArea.left) {
-      xNew = rWorkArea.left;
-   } else if ((xNew+wChild) > rWorkArea.right) {
-      xNew = rWorkArea.right - wChild;
-   }
-
-   // Calculate new Y position, then adjust for workarea
-   yNew = rParent.top  + ((hParent - hChild) /2);
-   if (yNew < rWorkArea.top) {
-      yNew = rWorkArea.top;
-   } else if ((yNew+hChild) > rWorkArea.bottom) {
-      yNew = rWorkArea.bottom - hChild;
-   }
-
-   // Set it, and return
-   return SetWindowPos (hwndChild, NULL, xNew, yNew, 0, 0, SWP_NOSIZE |
-          SWP_NOZORDER);
-}
-
-//----------------
-//  BuildPngList
-//----------------
-
-BOOL BuildPngList (PTSTR pstrPathName, TCHAR **ppFileList, int *pFileCount,
-     int *pFileIndex)
-{
-    static TCHAR              szImgPathName [MAX_PATH];
-    static TCHAR              szImgFileName [MAX_PATH];
-    static TCHAR              szImgFindName [MAX_PATH];
-
-    WIN32_FIND_DATA           finddata;
-    HANDLE                    hFind;
-
-    static TCHAR              szTmp [MAX_PATH];
-    BOOL                      bOk;
-    int                       i, ii;
-    int                       j, jj;
-
-    // free previous file-list
-
-    if (*ppFileList != NULL)
-    {
-        free (*ppFileList);
-        *ppFileList = NULL;
-    }
-
-    // extract foldername, filename and search-name
-
-    strcpy (szImgPathName, pstrPathName);
-    strcpy (szImgFileName, strrchr (pstrPathName, '\\') + 1);
-
-    strcpy (szImgFindName, szImgPathName);
-    *(strrchr (szImgFindName, '\\') + 1) = '\0';
-    strcat (szImgFindName, "*.png");
-
-    // first cycle: count number of files in directory for memory allocation
-
-    *pFileCount = 0;
-
-    hFind = FindFirstFile(szImgFindName, &finddata);
-    bOk = (hFind != (HANDLE) -1);
-
-    while (bOk)
-    {
-        *pFileCount += 1;
-        bOk = FindNextFile(hFind, &finddata);
-    }
-    FindClose(hFind);
-
-    // allocation memory for file-list
-
-    *ppFileList = (TCHAR *) malloc (*pFileCount * MAX_PATH);
-
-    // second cycle: read directory and store filenames in file-list
-
-    hFind = FindFirstFile(szImgFindName, &finddata);
-    bOk = (hFind != (HANDLE) -1);
-
-    i = 0;
-    ii = 0;
-    while (bOk)
-    {
-        strcpy (*ppFileList + ii, szImgPathName);
-        strcpy (strrchr(*ppFileList + ii, '\\') + 1, finddata.cFileName);
-
-        if (strcmp(pstrPathName, *ppFileList + ii) == 0)
-            *pFileIndex = i;
-
-        ii += MAX_PATH;
-        i++;
-
-        bOk = FindNextFile(hFind, &finddata);
-    }
-    FindClose(hFind);
-
-    // finally we must sort the file-list
-
-    for (i = 0; i < *pFileCount - 1; i++)
-    {
-        ii = i * MAX_PATH;
-        for (j = i+1; j < *pFileCount; j++)
-        {
-            jj = j * MAX_PATH;
-            if (strcmp (*ppFileList + ii, *ppFileList + jj) > 0)
-            {
-                strcpy (szTmp, *ppFileList + jj);
-                strcpy (*ppFileList + jj, *ppFileList + ii);
-                strcpy (*ppFileList + ii, szTmp);
-
-                // check if this was the current image that we moved
-
-                if (*pFileIndex == i)
-                    *pFileIndex = j;
-                else
-                    if (*pFileIndex == j)
-                        *pFileIndex = i;
-            }
-        }
-    }
-
-    return TRUE;
-}
-
-//----------------
-//  SearchPngList
-//----------------
-
-BOOL SearchPngList (
-        TCHAR *pFileList, int FileCount, int *pFileIndex,
-        PTSTR pstrPrevName, PTSTR pstrNextName)
-{
-    if (FileCount > 0)
-    {
-        // get previous entry
-        
-        if (pstrPrevName != NULL)
-        {
-            if (*pFileIndex > 0)
-                *pFileIndex -= 1;
-            else
-                *pFileIndex = FileCount - 1;
-            
-            strcpy (pstrPrevName, pFileList + (*pFileIndex * MAX_PATH));
-        }
-        
-        // get next entry
-        
-        if (pstrNextName != NULL)
-        {
-            if (*pFileIndex < FileCount - 1)
-                *pFileIndex += 1;
-            else
-                *pFileIndex = 0;
-            
-            strcpy (pstrNextName, pFileList + (*pFileIndex * MAX_PATH));
-        }
-        
-        return TRUE;
-    }
-    else
-    {
-        return FALSE;
-    }
-}
-
-//-----------------
-//  LoadImageFile
-//-----------------
-
-BOOL LoadImageFile (HWND hwnd, PTSTR pstrPathName,
-                png_byte **ppbImage, int *pxImgSize, int *pyImgSize,
-                int *piChannels, png_color *pBkgColor)
-{
-    static TCHAR szTmp [MAX_PATH];
-
-    // if there's an existing PNG, free the memory
-
-    if (*ppbImage)
-    {
-        free (*ppbImage);
-        *ppbImage = NULL;
-    }
-
-    // Load the entire PNG into memory
-
-    SetCursor (LoadCursor (NULL, IDC_WAIT));
-    ShowCursor (TRUE);
-
-    PngLoadImage (pstrPathName, ppbImage, pxImgSize, pyImgSize, piChannels,
-                  pBkgColor);
-
-    ShowCursor (FALSE);
-    SetCursor (LoadCursor (NULL, IDC_ARROW));
-
-    if (*ppbImage != NULL)
-    {
-        sprintf (szTmp, "VisualPng - %s", strrchr(pstrPathName, '\\') + 1);
-        SetWindowText (hwnd, szTmp);
-    }
-    else
-    {
-        MessageBox (hwnd, TEXT ("Error in loading the PNG image"),
-            szProgName, MB_ICONEXCLAMATION | MB_OK);
-        return FALSE;
-    }
-
-    return TRUE;
-}
-
-//----------------
-//  DisplayImage
-//----------------
-
-BOOL DisplayImage (HWND hwnd, BYTE **ppDib,
-        BYTE **ppDiData, int cxWinSize, int cyWinSize,
-        BYTE *pbImage, int cxImgSize, int cyImgSize, int cImgChannels,
-        BOOL bStretched)
-{
-    BYTE                       *pDib = *ppDib;
-    BYTE                       *pDiData = *ppDiData;
-    // BITMAPFILEHEADER        *pbmfh;
-    BITMAPINFOHEADER           *pbmih;
-    WORD                        wDIRowBytes;
-    png_color                   bkgBlack = {0, 0, 0};
-    png_color                   bkgGray  = {127, 127, 127};
-    png_color                   bkgWhite = {255, 255, 255};
-
-    // allocate memory for the Device Independant bitmap
-
-    wDIRowBytes = (WORD) ((3 * cxWinSize + 3L) >> 2) << 2;
-
-    if (pDib)
-    {
-        free (pDib);
-        pDib = NULL;
-    }
-
-    if (!(pDib = (BYTE *) malloc (sizeof(BITMAPINFOHEADER) +
-        wDIRowBytes * cyWinSize)))
-    {
-        MessageBox (hwnd, TEXT ("Error in displaying the PNG image"),
-            szProgName, MB_ICONEXCLAMATION | MB_OK);
-        *ppDib = pDib = NULL;
-        return FALSE;
-    }
-    *ppDib = pDib;
-    memset (pDib, 0, sizeof(BITMAPINFOHEADER));
-
-    // initialize the dib-structure
-
-    pbmih = (BITMAPINFOHEADER *) pDib;
-    pbmih->biSize = sizeof(BITMAPINFOHEADER);
-    pbmih->biWidth = cxWinSize;
-    pbmih->biHeight = -((long) cyWinSize);
-    pbmih->biPlanes = 1;
-    pbmih->biBitCount = 24;
-    pbmih->biCompression = 0;
-    pDiData = pDib + sizeof(BITMAPINFOHEADER);
-    *ppDiData = pDiData;
-
-    // first fill bitmap with gray and image border
-
-    InitBitmap (pDiData, cxWinSize, cyWinSize);
-
-    // then fill bitmap with image
-
-    if (pbImage)
-    {
-        FillBitmap (
-            pDiData, cxWinSize, cyWinSize,
-            pbImage, cxImgSize, cyImgSize, cImgChannels,
-            bStretched);
-    }
-
-    return TRUE;
-}
-
-//--------------
-//  InitBitmap
-//--------------
-
-BOOL InitBitmap (BYTE *pDiData, int cxWinSize, int cyWinSize)
-{
-    BYTE *dst;
-    int x, y, col;
-
-    // initialize the background with gray
-
-    dst = pDiData;
-    for (y = 0; y < cyWinSize; y++)
-    {
-        col = 0;
-        for (x = 0; x < cxWinSize; x++)
-        {
-            // fill with GRAY
-            *dst++ = 127;
-            *dst++ = 127;
-            *dst++ = 127;
-            col += 3;
-        }
-        // rows start on 4 byte boundaries
-        while ((col % 4) != 0)
-        {
-            dst++;
-            col++;
-        }
-    }
-
-    return TRUE;
-}
-
-//--------------
-//  FillBitmap
-//--------------
-
-BOOL FillBitmap (
-        BYTE *pDiData, int cxWinSize, int cyWinSize,
-        BYTE *pbImage, int cxImgSize, int cyImgSize, int cImgChannels,
-        BOOL bStretched)
-{
-    BYTE *pStretchedImage;
-    BYTE *pImg;
-    BYTE *src, *dst;
-    BYTE r, g, b, a;
-    const int cDIChannels = 3;
-    WORD wImgRowBytes;
-    WORD wDIRowBytes;
-    int cxNewSize, cyNewSize;
-    int cxImgPos, cyImgPos;
-    int xImg, yImg;
-    int xWin, yWin;
-    int xOld, yOld;
-    int xNew, yNew;
-
-    if (bStretched)
-    {
-        cxNewSize = cxWinSize - 2 * MARGIN;
-        cyNewSize = cyWinSize - 2 * MARGIN;
-
-        // stretch the image to it's window determined size
-
-        // the following two are the same, but the first has side-effects
-        // because of rounding
-//      if ((cyNewSize / cxNewSize) > (cyImgSize / cxImgSize))
-        if ((cyNewSize * cxImgSize) > (cyImgSize * cxNewSize))
-        {
-            cyNewSize = cxNewSize * cyImgSize / cxImgSize;
-            cxImgPos = MARGIN;
-            cyImgPos = (cyWinSize - cyNewSize) / 2;
-        }
-        else
-        {
-            cxNewSize = cyNewSize * cxImgSize / cyImgSize;
-            cyImgPos = MARGIN;
-            cxImgPos = (cxWinSize - cxNewSize) / 2;
-        }
-
-        pStretchedImage = malloc (cImgChannels * cxNewSize * cyNewSize);
-        pImg = pStretchedImage;
-
-        for (yNew = 0; yNew < cyNewSize; yNew++)
-        {
-            yOld = yNew * cyImgSize / cyNewSize;
-            for (xNew = 0; xNew < cxNewSize; xNew++)
-            {
-                xOld = xNew * cxImgSize / cxNewSize;
-
-                r = *(pbImage + cImgChannels * ((yOld * cxImgSize) + xOld) + 0);
-                g = *(pbImage + cImgChannels * ((yOld * cxImgSize) + xOld) + 1);
-                b = *(pbImage + cImgChannels * ((yOld * cxImgSize) + xOld) + 2);
-                *pImg++ = r;
-                *pImg++ = g;
-                *pImg++ = b;
-                if (cImgChannels == 4)
-                {
-                    a = *(pbImage + cImgChannels * ((yOld * cxImgSize) + xOld)
-                        + 3);
-                    *pImg++ = a;
-                }
-            }
-        }
-
-        // calculate row-bytes
-
-        wImgRowBytes = cImgChannels * cxNewSize;
-        wDIRowBytes = (WORD) ((cDIChannels * cxWinSize + 3L) >> 2) << 2;
-
-        // copy image to screen
-
-        for (yImg = 0, yWin = cyImgPos; yImg < cyNewSize; yImg++, yWin++)
-        {
-            if (yWin >= cyWinSize - cyImgPos)
-                break;
-            src = pStretchedImage + yImg * wImgRowBytes;
-            dst = pDiData + yWin * wDIRowBytes + cxImgPos * cDIChannels;
-
-            for (xImg = 0, xWin = cxImgPos; xImg < cxNewSize; xImg++, xWin++)
-            {
-                if (xWin >= cxWinSize - cxImgPos)
-                    break;
-                r = *src++;
-                g = *src++;
-                b = *src++;
-                *dst++ = b; /* note the reverse order */
-                *dst++ = g;
-                *dst++ = r;
-                if (cImgChannels == 4)
-                {
-                    a = *src++;
-                }
-            }
-        }
-
-        // free memory
-
-        if (pStretchedImage != NULL)
-        {
-            free (pStretchedImage);
-            pStretchedImage = NULL;
-        }
-
-    }
-
-    // process the image not-stretched
-
-    else
-    {
-        // calculate the central position
-
-        cxImgPos = (cxWinSize - cxImgSize) / 2;
-        cyImgPos = (cyWinSize - cyImgSize) / 2;
-
-        // check for image larger than window
-
-        if (cxImgPos < MARGIN)
-            cxImgPos = MARGIN;
-        if (cyImgPos < MARGIN)
-            cyImgPos = MARGIN;
-
-        // calculate both row-bytes
-
-        wImgRowBytes = cImgChannels * cxImgSize;
-        wDIRowBytes = (WORD) ((cDIChannels * cxWinSize + 3L) >> 2) << 2;
-
-        // copy image to screen
-
-        for (yImg = 0, yWin = cyImgPos; yImg < cyImgSize; yImg++, yWin++)
-        {
-            if (yWin >= cyWinSize - MARGIN)
-                break;
-            src = pbImage + yImg * wImgRowBytes;
-            dst = pDiData + yWin * wDIRowBytes + cxImgPos * cDIChannels;
-
-            for (xImg = 0, xWin = cxImgPos; xImg < cxImgSize; xImg++, xWin++)
-            {
-                if (xWin >= cxWinSize - MARGIN)
-                    break;
-                r = *src++;
-                g = *src++;
-                b = *src++;
-                *dst++ = b; /* note the reverse order */
-                *dst++ = g;
-                *dst++ = r;
-                if (cImgChannels == 4)
-                {
-                    a = *src++;
-                }
-            }
-        }
-    }
-
-    return TRUE;
-}
-
-//-----------------
-//  end of source
-//-----------------
diff --git a/contrib/visupng/VisualPng.dsp b/contrib/visupng/VisualPng.dsp
deleted file mode 100644
index c13c5a7..0000000
--- a/contrib/visupng/VisualPng.dsp
+++ /dev/null
@@ -1,147 +0,0 @@
-# Microsoft Developer Studio Project File - Name="VisualPng" - Package Owner=<4>
-# Microsoft Developer Studio Generated Build File, Format Version 6.00
-# ** DO NOT EDIT **
-
-# TARGTYPE "Win32 (x86) Application" 0x0101
-
-CFG=VisualPng - Win32 Debug
-!MESSAGE This is not a valid makefile. To build this project using NMAKE,
-!MESSAGE use the Export Makefile command and run
-!MESSAGE 
-!MESSAGE NMAKE /f "VisualPng.mak".
-!MESSAGE 
-!MESSAGE You can specify a configuration when running NMAKE
-!MESSAGE by defining the macro CFG on the command line. For example:
-!MESSAGE 
-!MESSAGE NMAKE /f "VisualPng.mak" CFG="VisualPng - Win32 Debug"
-!MESSAGE 
-!MESSAGE Possible choices for configuration are:
-!MESSAGE 
-!MESSAGE "VisualPng - Win32 Release" (based on "Win32 (x86) Application")
-!MESSAGE "VisualPng - Win32 Debug" (based on "Win32 (x86) Application")
-!MESSAGE 
-
-# Begin Project
-# PROP AllowPerConfigDependencies 0
-# PROP Scc_ProjName ""
-# PROP Scc_LocalPath ""
-CPP=cl.exe
-MTL=midl.exe
-RSC=rc.exe
-
-!IF  "$(CFG)" == "VisualPng - Win32 Release"
-
-# PROP BASE Use_MFC 0
-# PROP BASE Use_Debug_Libraries 0
-# PROP BASE Output_Dir "Release"
-# PROP BASE Intermediate_Dir "Release"
-# PROP BASE Ignore_Export_Lib 0
-# PROP BASE Target_Dir ""
-# PROP Use_MFC 0
-# PROP Use_Debug_Libraries 0
-# PROP Output_Dir "Release"
-# PROP Intermediate_Dir "Release"
-# PROP Ignore_Export_Lib 0
-# PROP Target_Dir ""
-# ADD BASE CPP /nologo /W3 /O2 /I "..\.." /I "..\..\..\zlib" /D "WIN32" /D "NDEBUG" /D "PNG_NO_STDIO" /D "PNG_NO_GLOBAL_ARRAYS" /FD /c
-# SUBTRACT BASE CPP /YX
-# ADD CPP /nologo /MD /W3 /O2 /I "..\.." /I "..\..\..\zlib" /D "WIN32" /D "NDEBUG" /D "PNG_NO_STDIO" /D "PNG_NO_GLOBAL_ARRAYS" /FD /c
-# SUBTRACT CPP /YX
-# ADD BASE MTL /nologo /D "NDEBUG" /mktyplib203 /win32
-# ADD MTL /nologo /D "NDEBUG" /mktyplib203 /win32
-# ADD BASE RSC /l 0x409 /d "NDEBUG"
-# ADD RSC /l 0x409 /d "NDEBUG"
-BSC32=bscmake.exe
-# ADD BASE BSC32 /nologo
-# ADD BSC32 /nologo
-LINK32=link.exe
-# ADD BASE LINK32 kernel32.lib user32.lib gdi32.lib winspool.lib comdlg32.lib advapi32.lib shell32.lib ole32.lib oleaut32.lib uuid.lib odbc32.lib odbccp32.lib /nologo /subsystem:windows /machine:I386
-# ADD LINK32 ..\..\projects\visualc6\Win32_LIB_Release\libpng.lib ..\..\..\zlib\projects\visualc6\Win32_LIB_Release\zlib.lib kernel32.lib user32.lib gdi32.lib winspool.lib comdlg32.lib advapi32.lib shell32.lib ole32.lib oleaut32.lib uuid.lib odbc32.lib odbccp32.lib /nologo /subsystem:windows /machine:I386
-# Begin Special Build Tool
-OutDir=.\Release
-SOURCE="$(InputPath)"
-PostBuild_Cmds=$(outdir)\VisualPng.exe ..\..\contrib\pngsuite\basn6a16.png
-# End Special Build Tool
-
-!ELSEIF  "$(CFG)" == "VisualPng - Win32 Debug"
-
-# PROP BASE Use_MFC 0
-# PROP BASE Use_Debug_Libraries 1
-# PROP BASE Output_Dir "Debug"
-# PROP BASE Intermediate_Dir "Debug"
-# PROP BASE Ignore_Export_Lib 0
-# PROP BASE Target_Dir ""
-# PROP Use_MFC 0
-# PROP Use_Debug_Libraries 1
-# PROP Output_Dir "Debug"
-# PROP Intermediate_Dir "Debug"
-# PROP Ignore_Export_Lib 0
-# PROP Target_Dir ""
-# ADD BASE CPP /nologo /W3 /Gm /ZI /Od /I "..\.." /I "..\..\..\zlib" /D "WIN32" /D "_DEBUG" /D "PNG_NO_STDIO" /D "PNG_NO_GLOBAL_ARRAYS" /FD /GZ /c
-# SUBTRACT BASE CPP /YX
-# ADD CPP /nologo /MDd /W3 /Gm /ZI /Od /I "..\.." /I "..\..\..\zlib" /D "WIN32" /D "_DEBUG" /D "PNG_NO_STDIO" /D "PNG_NO_GLOBAL_ARRAYS" /FD /GZ /c
-# SUBTRACT CPP /YX
-# ADD BASE MTL /nologo /D "_DEBUG" /mktyplib203 /win32
-# ADD MTL /nologo /D "_DEBUG" /mktyplib203 /win32
-# ADD BASE RSC /l 0x409 /d "_DEBUG"
-# ADD RSC /l 0x409 /d "_DEBUG"
-BSC32=bscmake.exe
-# ADD BASE BSC32 /nologo
-# ADD BSC32 /nologo
-LINK32=link.exe
-# ADD BASE LINK32 kernel32.lib user32.lib gdi32.lib winspool.lib comdlg32.lib advapi32.lib shell32.lib ole32.lib oleaut32.lib uuid.lib odbc32.lib odbccp32.lib /nologo /subsystem:windows /debug /machine:I386 /pdbtype:sept
-# ADD LINK32 ..\..\projects\visualc6\Win32_LIB_Release\libpng.lib ..\..\..\zlib\projects\visualc6\Win32_LIB_Release\zlib.lib kernel32.lib user32.lib gdi32.lib winspool.lib comdlg32.lib advapi32.lib shell32.lib ole32.lib oleaut32.lib uuid.lib odbc32.lib odbccp32.lib /nologo /subsystem:windows /debug /machine:I386 /nodefaultlib:"msvcrt.lib" /pdbtype:sept
-# Begin Special Build Tool
-OutDir=.\Debug
-SOURCE="$(InputPath)"
-PostBuild_Cmds=$(outdir)\VisualPng.exe ..\..\contrib\pngsuite\basn6a16.png
-# End Special Build Tool
-
-!ENDIF 
-
-# Begin Target
-
-# Name "VisualPng - Win32 Release"
-# Name "VisualPng - Win32 Debug"
-# Begin Group "Source Files"
-
-# PROP Default_Filter "cpp;c;cxx;rc;def;r;odl;idl;hpj;bat"
-# Begin Source File
-
-SOURCE=.\PngFile.c
-# End Source File
-# Begin Source File
-
-SOURCE=.\VisualPng.c
-# End Source File
-# End Group
-# Begin Group "Header Files"
-
-# PROP Default_Filter "h;hpp;hxx;hm;inl"
-# Begin Source File
-
-SOURCE=.\cexcept.h
-# End Source File
-# Begin Source File
-
-SOURCE=.\PngFile.h
-# End Source File
-# Begin Source File
-
-SOURCE=.\resource.h
-# End Source File
-# End Group
-# Begin Group "Resource Files"
-
-# PROP Default_Filter "ico;cur;bmp;dlg;rc2;rct;bin;rgs;gif;jpg;jpeg;jpe"
-# Begin Source File
-
-SOURCE=.\VisualPng.ico
-# End Source File
-# Begin Source File
-
-SOURCE=.\VisualPng.rc
-# End Source File
-# End Group
-# End Target
-# End Project
diff --git a/contrib/visupng/VisualPng.dsw b/contrib/visupng/VisualPng.dsw
deleted file mode 100644
index 17ad83a..0000000
--- a/contrib/visupng/VisualPng.dsw
+++ /dev/null
@@ -1,29 +0,0 @@
-Microsoft Developer Studio Workspace File, Format Version 6.00
-# WARNING: DO NOT EDIT OR DELETE THIS WORKSPACE FILE!
-
-###############################################################################
-
-Project: "VisualPng"=.\VisualPng.dsp - Package Owner=<4>
-
-Package=<5>
-{{{
-}}}
-
-Package=<4>
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-
-###############################################################################
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-
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-
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diff --git a/contrib/visupng/VisualPng.ico b/contrib/visupng/VisualPng.ico
deleted file mode 100644
index 68aa371..0000000
--- a/contrib/visupng/VisualPng.ico
+++ /dev/null
diff --git a/contrib/visupng/VisualPng.png b/contrib/visupng/VisualPng.png
deleted file mode 100644
index c6aa80a..0000000
--- a/contrib/visupng/VisualPng.png
+++ /dev/null
diff --git a/contrib/visupng/VisualPng.rc b/contrib/visupng/VisualPng.rc
deleted file mode 100644
index 151c68c..0000000
--- a/contrib/visupng/VisualPng.rc
+++ /dev/null
@@ -1,152 +0,0 @@
-//Microsoft Developer Studio generated resource script.
-//
-#include "resource.h"
-
-#define APSTUDIO_READONLY_SYMBOLS
-/////////////////////////////////////////////////////////////////////////////
-//
-// Generated from the TEXTINCLUDE 2 resource.
-//
-#include "afxres.h"
-
-/////////////////////////////////////////////////////////////////////////////
-#undef APSTUDIO_READONLY_SYMBOLS
-
-/////////////////////////////////////////////////////////////////////////////
-// English (U.S.) resources
-
-#if !defined(AFX_RESOURCE_DLL) || defined(AFX_TARG_ENU)
-#ifdef _WIN32
-LANGUAGE LANG_ENGLISH, SUBLANG_ENGLISH_US
-#pragma code_page(1252)
-#endif //_WIN32
-
-#ifdef APSTUDIO_INVOKED
-/////////////////////////////////////////////////////////////////////////////
-//
-// TEXTINCLUDE
-//
-
-1 TEXTINCLUDE DISCARDABLE 
-BEGIN
-    "resource.h\0"
-END
-
-2 TEXTINCLUDE DISCARDABLE 
-BEGIN
-    "#include ""afxres.h""\r\n"
-    "\0"
-END
-
-3 TEXTINCLUDE DISCARDABLE 
-BEGIN
-    "\r\n"
-    "\0"
-END
-
-#endif    // APSTUDIO_INVOKED
-
-
-/////////////////////////////////////////////////////////////////////////////
-//
-// Menu
-//
-
-VISUALPNG MENU DISCARDABLE 
-BEGIN
-    POPUP "&File"
-    BEGIN
-        MENUITEM "&Open Image...\tCtrl+O",      IDM_FILE_OPEN
-        MENUITEM "Save &As...",                 IDM_FILE_SAVE
-        MENUITEM SEPARATOR
-        MENUITEM "&Next Image\tCtrl+N",         IDM_FILE_NEXT
-        MENUITEM "Pre&vious Image\tCtrl+V",     IDM_FILE_PREVIOUS
-        MENUITEM SEPARATOR
-        MENUITEM "E&xit\tAlt+X",                IDM_FILE_EXIT
-    END
-    POPUP "&Options"
-    BEGIN
-        MENUITEM "&Stretch",                    IDM_OPTIONS_STRETCH, CHECKED
-    END
-    POPUP "&Help"
-    BEGIN
-        MENUITEM "&About",                      IDM_HELP_ABOUT
-    END
-END
-
-
-/////////////////////////////////////////////////////////////////////////////
-//
-// Accelerator
-//
-
-VISUALPNG ACCELERATORS DISCARDABLE 
-BEGIN
-    "N",            IDM_FILE_NEXT,          VIRTKEY, CONTROL, NOINVERT
-    "O",            IDM_FILE_OPEN,          VIRTKEY, CONTROL, NOINVERT
-    "P",            IDM_FILE_PREVIOUS,      VIRTKEY, CONTROL, NOINVERT
-    "V",            IDM_FILE_PREVIOUS,      VIRTKEY, CONTROL, NOINVERT
-    "X",            IDM_FILE_EXIT,          VIRTKEY, ALT, NOINVERT
-END
-
-
-/////////////////////////////////////////////////////////////////////////////
-//
-// Icon
-//
-
-// Icon with lowest ID value placed first to ensure application icon
-// remains consistent on all systems.
-VISUALPNG               ICON    DISCARDABLE     "VisualPng.ico"
-
-/////////////////////////////////////////////////////////////////////////////
-//
-// Dialog
-//
-
-ABOUTBOX DIALOG DISCARDABLE  0, 0, 186, 94
-STYLE DS_MODALFRAME | WS_POPUP
-FONT 8, "MS Sans Serif"
-BEGIN
-    DEFPUSHBUTTON   "OK",IDOK,68,67,50,14
-    CTEXT           "VisualPng 1.0  -  June 2000",IDC_STATIC,49,14,88,8
-    LTEXT           "a PNG image viewer",IDC_STATIC,60,30,66,8
-    LTEXT           "(c) Willem van Schaik, 2000",IDC_STATIC,48,52,90,8
-    LTEXT           "to demonstrate the use of libpng in Visual C",
-                    IDC_STATIC,25,38,136,8
-END
-
-
-/////////////////////////////////////////////////////////////////////////////
-//
-// DESIGNINFO
-//
-
-#ifdef APSTUDIO_INVOKED
-GUIDELINES DESIGNINFO DISCARDABLE 
-BEGIN
-    "ABOUTBOX", DIALOG
-    BEGIN
-        LEFTMARGIN, 7
-        RIGHTMARGIN, 179
-        TOPMARGIN, 7
-        BOTTOMMARGIN, 87
-    END
-END
-#endif    // APSTUDIO_INVOKED
-
-#endif    // English (U.S.) resources
-/////////////////////////////////////////////////////////////////////////////
-
-
-
-#ifndef APSTUDIO_INVOKED
-/////////////////////////////////////////////////////////////////////////////
-//
-// Generated from the TEXTINCLUDE 3 resource.
-//
-
-
-/////////////////////////////////////////////////////////////////////////////
-#endif    // not APSTUDIO_INVOKED
-
diff --git a/contrib/visupng/cexcept.h b/contrib/visupng/cexcept.h
deleted file mode 100644
index dbea51e..0000000
--- a/contrib/visupng/cexcept.h
+++ /dev/null
@@ -1,243 +0,0 @@
-/*===
-cexcept.h 2.0.0 (2001-Jul-12-Thu)
-Adam M. Costello <amc@cs.berkeley.edu>
-
-An interface for exception-handling in ANSI C (C89 and subsequent ISO
-standards), developed jointly with Cosmin Truta <cosmin@cs.toronto.edu>.
-
-    Copyright (c) 2001 Adam M. Costello and Cosmin Truta.  Everyone
-    is hereby granted permission to do whatever they like with this
-    file, provided that if they modify it they take reasonable steps to
-    avoid confusing or misleading people about the authors, version,
-    and terms of use of the derived file.  The copyright holders make
-    no guarantees regarding this file, and are not responsible for any
-    damage resulting from its use.
-
-Only user-defined exceptions are supported, not "real" exceptions like
-division by zero or memory segmentation violations.
-
-If this interface is used by multiple .c files, they shouldn't include
-this header file directly.  Instead, create a wrapper header file that
-includes this header file and then invokes the define_exception_type
-macro (see below), and let your .c files include that header file.
-
-The interface consists of one type, one well-known name, and six macros.
-
-
-define_exception_type(type_name);
-
-    This macro is used like an external declaration.  It specifies
-    the type of object that gets copied from the exception thrower to
-    the exception catcher.  The type_name can be any type that can be
-    assigned to, that is, a non-constant arithmetic type, struct, union,
-    or pointer.  Examples:
-
-        define_exception_type(int);
-
-        enum exception { out_of_memory, bad_arguments, disk_full };
-        define_exception_type(enum exception);
-
-        struct exception { int code; const char *msg; };
-        define_exception_type(struct exception);
-
-    Because throwing an exception causes the object to be copied (not
-    just once, but twice), programmers may wish to consider size when
-    choosing the exception type.
-
-
-struct exception_context;
-
-    This type may be used after the define_exception_type() macro has
-    been invoked.  A struct exception_context must be known to both
-    the thrower and the catcher.  It is expected that there be one
-    context for each thread that uses exceptions.  It would certainly
-    be dangerous for multiple threads to access the same context.
-    One thread can use multiple contexts, but that is likely to be
-    confusing and not typically useful.  The application can allocate
-    this structure in any way it pleases--automatic, static, or dynamic.
-    The application programmer should pretend not to know the structure
-    members, which are subject to change.
-
-
-struct exception_context *the_exception_context;
-
-    The Try/Catch and Throw statements (described below) implicitly
-    refer to a context, using the name the_exception_context.  It is
-    the application's responsibility to make sure that this name yields
-    the address of a mutable (non-constant) struct exception_context
-    wherever those statements are used.  Subject to that constraint, the
-    application may declare a variable of this name anywhere it likes
-    (inside a function, in a parameter list, or externally), and may
-    use whatever storage class specifiers (static, extern, etc) or type
-    qualifiers (const, volatile, etc) it likes.  Examples:
-
-        static struct exception_context
-          * const the_exception_context = &foo;
-
-        { struct exception_context *the_exception_context = bar; ... }
-
-        int blah(struct exception_context *the_exception_context, ...);
-
-        extern struct exception_context the_exception_context[1];
-
-    The last example illustrates a trick that avoids creating a pointer
-    object separate from the structure object.
-
-    The name could even be a macro, for example:
-
-        struct exception_context ec_array[numthreads];
-        #define the_exception_context (ec_array + thread_id)
-
-    Be aware that the_exception_context is used several times by the
-    Try/Catch/Throw macros, so it shouldn't be expensive or have side
-    effects.  The expansion must be a drop-in replacement for an
-    identifier, so it's safest to put parentheses around it.
-
-
-void init_exception_context(struct exception_context *ec);
-
-    For context structures allocated statically (by an external
-    definition or using the "static" keyword), the implicit
-    initialization to all zeros is sufficient, but contexts allocated
-    by other means must be initialized using this macro before they
-    are used by a Try/Catch statement.  It does no harm to initialize
-    a context more than once (by using this macro on a statically
-    allocated context, or using this macro twice on the same context),
-    but a context must not be re-initialized after it has been used by a
-    Try/Catch statement.
-
-
-Try statement
-Catch (expression) statement
-
-    The Try/Catch/Throw macros are capitalized in order to avoid
-    confusion with the C++ keywords, which have subtly different
-    semantics.
-
-    A Try/Catch statement has a syntax similar to an if/else statement,
-    except that the parenthesized expression goes after the second
-    keyword rather than the first.  As with if/else, there are two
-    clauses, each of which may be a simple statement ending with a
-    semicolon or a brace-enclosed compound statement.  But whereas
-    the else clause is optional, the Catch clause is required.  The
-    expression must be a modifiable lvalue (something capable of being
-    assigned to) of the same type (disregarding type qualifiers) that
-    was passed to define_exception_type().
-
-    If a Throw that uses the same exception context as the Try/Catch is
-    executed within the Try clause (typically within a function called
-    by the Try clause), and the exception is not caught by a nested
-    Try/Catch statement, then a copy of the exception will be assigned
-    to the expression, and control will jump to the Catch clause.  If no
-    such Throw is executed, then the assignment is not performed, and
-    the Catch clause is not executed.
-
-    The expression is not evaluated unless and until the exception is
-    caught, which is significant if it has side effects, for example:
-
-        Try foo();
-        Catch (p[++i].e) { ... }
-
-    IMPORTANT: Jumping into or out of a Try clause (for example via
-    return, break, continue, goto, longjmp) is forbidden--the compiler
-    will not complain, but bad things will happen at run-time.  Jumping
-    into or out of a Catch clause is okay, and so is jumping around
-    inside a Try clause.  In many cases where one is tempted to return
-    from a Try clause, it will suffice to use Throw, and then return
-    from the Catch clause.  Another option is to set a flag variable and
-    use goto to jump to the end of the Try clause, then check the flag
-    after the Try/Catch statement.
-
-    IMPORTANT: The values of any non-volatile automatic variables
-    changed within the Try clause are undefined after an exception is
-    caught.  Therefore, variables modified inside the Try block whose
-    values are needed later outside the Try block must either use static
-    storage or be declared with the "volatile" type qualifier.
-
-
-Throw expression;
-
-    A Throw statement is very much like a return statement, except that
-    the expression is required.  Whereas return jumps back to the place
-    where the current function was called, Throw jumps back to the Catch
-    clause of the innermost enclosing Try clause.  The expression must
-    be compatible with the type passed to define_exception_type().  The
-    exception must be caught, otherwise the program may crash.
-
-    Slight limitation:  If the expression is a comma-expression it must
-    be enclosed in parentheses.
-
-
-Try statement
-Catch_anonymous statement
-
-    When the value of the exception is not needed, a Try/Catch statement
-    can use Catch_anonymous instead of Catch (expression).
-
-
-Everything below this point is for the benefit of the compiler.  The
-application programmer should pretend not to know any of it, because it
-is subject to change.
-
-===*/
-
-
-#ifndef CEXCEPT_H
-#define CEXCEPT_H
-
-
-#include <setjmp.h>
-
-#define define_exception_type(etype) \
-struct exception_context { \
-  jmp_buf *penv; \
-  int caught; \
-  volatile struct { etype etmp; } v; \
-}
-
-/* etmp must be volatile because the application might use automatic */
-/* storage for the_exception_context, and etmp is modified between   */
-/* the calls to setjmp() and longjmp().  A wrapper struct is used to */
-/* avoid warnings about a duplicate volatile qualifier in case etype */
-/* already includes it.                                              */
-
-#define init_exception_context(ec) ((void)((ec)->penv = 0))
-
-#define Try \
-  { \
-    jmp_buf *exception__prev, exception__env; \
-    exception__prev = the_exception_context->penv; \
-    the_exception_context->penv = &exception__env; \
-    if (setjmp(exception__env) == 0) { \
-      if (&exception__prev)
-
-#define exception__catch(action) \
-      else { } \
-      the_exception_context->caught = 0; \
-    } \
-    else { \
-      the_exception_context->caught = 1; \
-    } \
-    the_exception_context->penv = exception__prev; \
-  } \
-  if (!the_exception_context->caught || action) { } \
-  else
-
-#define Catch(e) exception__catch(((e) = the_exception_context->v.etmp, 0))
-#define Catch_anonymous exception__catch(0)
-
-/* Try ends with if(), and Catch begins and ends with else.  This     */
-/* ensures that the Try/Catch syntax is really the same as the        */
-/* if/else syntax.                                                    */
-/*                                                                    */
-/* We use &exception__prev instead of 1 to appease compilers that     */
-/* warn about constant expressions inside if().  Most compilers       */
-/* should still recognize that &exception__prev is never zero and     */
-/* avoid generating test code.                                        */
-
-#define Throw \
-  for (;; longjmp(*the_exception_context->penv, 1)) \
-    the_exception_context->v.etmp =
-
-
-#endif /* CEXCEPT_H */
diff --git a/contrib/visupng/resource.h b/contrib/visupng/resource.h
deleted file mode 100644
index 611dd03..0000000
--- a/contrib/visupng/resource.h
+++ /dev/null
@@ -1,23 +0,0 @@
-//{{NO_DEPENDENCIES}}
-// Microsoft Developer Studio generated include file.
-// Used by VisualPng.rc
-//
-#define IDM_FILE_OPEN                   40001
-#define IDM_FILE_SAVE                   40002
-#define IDM_FILE_NEXT                   40003
-#define IDM_FILE_PREVIOUS               40004
-#define IDM_FILE_EXIT                   40005
-#define IDM_OPTIONS_BACKGROUND          40006
-#define IDM_OPTIONS_STRETCH             40007
-#define IDM_HELP_ABOUT                  40008
-
-// Next default values for new objects
-// 
-#ifdef APSTUDIO_INVOKED
-#ifndef APSTUDIO_READONLY_SYMBOLS
-#define _APS_NEXT_RESOURCE_VALUE        113
-#define _APS_NEXT_COMMAND_VALUE         40009
-#define _APS_NEXT_CONTROL_VALUE         1001
-#define _APS_NEXT_SYMED_VALUE           101
-#endif
-#endif