aboutsummaryrefslogtreecommitdiffstats
path: root/libpng.3
diff options
context:
space:
mode:
Diffstat (limited to 'libpng.3')
-rw-r--r--libpng.3392
1 files changed, 275 insertions, 117 deletions
diff --git a/libpng.3 b/libpng.3
index 7f68564..93139a7 100644
--- a/libpng.3
+++ b/libpng.3
@@ -1,6 +1,6 @@
-.TH LIBPNG 3 "July 16, 2009"
+.TH LIBPNG 3 "June 26, 2010"
.SH NAME
-libpng \- Portable Network Graphics (PNG) Reference Library 1.2.38
+libpng \- Portable Network Graphics (PNG) Reference Library 1.2.44
.SH SYNOPSIS
\fI\fB
@@ -821,16 +821,18 @@ Following is a copy of the libpng.txt file that accompanies libpng.
.SH LIBPNG.TXT
libpng.txt - A description on how to use and modify libpng
- libpng version 1.2.38 - July 16, 2009
+ libpng version 1.2.44 - June 26, 2010
Updated and distributed by Glenn Randers-Pehrson
<glennrp at users.sourceforge.net>
Copyright (c) 1998-2009 Glenn Randers-Pehrson
- For conditions of distribution and use, see copyright
- notice in png.h.
+
+ This document is released under the libpng license.
+ For conditions of distribution and use, see the disclaimer
+ and license in png.h
Based on:
- libpng versions 0.97, January 1998, through 1.2.38 - July 16, 2009
+ libpng versions 0.97, January 1998, through 1.2.44 - June 26, 2010
Updated and distributed by Glenn Randers-Pehrson
Copyright (c) 1998-2009 Glenn Randers-Pehrson
@@ -859,8 +861,8 @@ will need. We assume that libpng is already installed; see the
INSTALL file for instructions on how to install libpng.
For examples of libpng usage, see the files "example.c", "pngtest.c",
-and the files in the "contrib" directory, all of which are included in the
-libpng distribution.
+and the files in the "contrib" directory, all of which are included in
+the libpng distribution.
Libpng was written as a companion to the PNG specification, as a way
of reducing the amount of time and effort it takes to support the PNG
@@ -1229,6 +1231,19 @@ If you need to retrieve the limits that are being applied, use
width_max = png_get_user_width_max(png_ptr);
height_max = png_get_user_height_max(png_ptr);
+The PNG specification sets no limit on the number of ancillary chunks
+allowed in a PNG datastream. You can impose a limit on the total number
+of sPLT, tEXt, iTXt, zTXt, and unknown chunks that will be stored, with
+
+ png_set_chunk_cache_max(png_ptr, user_chunk_cache_max);
+
+where 0x7fffffffL means unlimited. You can retrieve this limit with
+
+ chunk_cache_max = png_get_chunk_cache_max(png_ptr);
+
+This limit also applies to the number of buffers that can be allocated
+by png_decompress_chunk() while decompressing iTXt, zTXt, and iCCP chunks.
+
.SS The high-level read interface
At this point there are two ways to proceed; through the high-level
@@ -1256,14 +1271,16 @@ you want to do are limited to the following set:
PNG_TRANSFORM_INVERT_ALPHA Change alpha from opacity
to transparency
PNG_TRANSFORM_SWAP_ENDIAN Byte-swap 16-bit samples
+ PNG_TRANSFORM_GRAY_TO_RGB Expand grayscale samples
+ to RGB (or GA to RGBA)
(This excludes setting a background color, doing gamma transformation,
dithering, and setting filler.) If this is the case, simply do this:
png_read_png(png_ptr, info_ptr, png_transforms, NULL)
-where png_transforms is an integer containing the bitwise OR of
-some set of transformation flags. This call is equivalent to png_read_info(),
+where png_transforms is an integer containing the bitwise OR of some
+set of transformation flags. This call is equivalent to png_read_info(),
followed the set of transformations indicated by the transform mask,
then png_read_image(), and finally png_read_end().
@@ -1364,10 +1381,33 @@ in until png_read_end() has read the chunk data following the image.
for PNG 1.0)
interlace_type - (PNG_INTERLACE_NONE or
PNG_INTERLACE_ADAM7)
- Any or all of interlace_type, compression_type, of
+
+ Any or all of interlace_type, compression_type, or
filter_method can be NULL if you are
not interested in their values.
+ Note that png_get_IHDR() returns 32-bit data into
+ the application's width and height variables.
+ This is an unsafe situation if these are 16-bit
+ variables. In such situations, the
+ png_get_image_width() and png_get_image_height()
+ functions described below are safer.
+
+ width = png_get_image_width(png_ptr,
+ info_ptr);
+ height = png_get_image_height(png_ptr,
+ info_ptr);
+ bit_depth = png_get_bit_depth(png_ptr,
+ info_ptr);
+ color_type = png_get_color_type(png_ptr,
+ info_ptr);
+ filter_method = png_get_filter_type(png_ptr,
+ info_ptr);
+ compression_type = png_get_compression_type(png_ptr,
+ info_ptr);
+ interlace_type = png_get_interlace_type(png_ptr,
+ info_ptr);
+
channels = png_get_channels(png_ptr, info_ptr);
channels - number of channels of info for the
color type (valid values are 1 (GRAY,
@@ -1387,29 +1427,12 @@ in until png_read_end() has read the chunk data following the image.
be in signature[4] through signature[7]
(see png_set_sig_bytes())).
-
- width = png_get_image_width(png_ptr,
- info_ptr);
- height = png_get_image_height(png_ptr,
- info_ptr);
- bit_depth = png_get_bit_depth(png_ptr,
- info_ptr);
- color_type = png_get_color_type(png_ptr,
- info_ptr);
- filter_method = png_get_filter_type(png_ptr,
- info_ptr);
- compression_type = png_get_compression_type(png_ptr,
- info_ptr);
- interlace_type = png_get_interlace_type(png_ptr,
- info_ptr);
-
-
These are also important, but their validity depends on whether the chunk
has been read. The png_get_valid(png_ptr, info_ptr, PNG_INFO_<chunk>) and
png_get_<chunk>(png_ptr, info_ptr, ...) functions return non-zero if the
data has been read, or zero if it is missing. The parameters to the
-png_get_<chunk> are set directly if they are simple data types, or a pointer
-into the info_ptr is returned for any complex types.
+png_get_<chunk> are set directly if they are simple data types, or a
+pointer into the info_ptr is returned for any complex types.
png_get_PLTE(png_ptr, info_ptr, &palette,
&num_palette);
@@ -1449,8 +1472,8 @@ into the info_ptr is returned for any complex types.
png_get_tRNS(png_ptr, info_ptr, &trans, &num_trans,
&trans_values);
- trans - array of transparent entries for
- palette (PNG_INFO_tRNS)
+ trans - array of transparent
+ entries for palette (PNG_INFO_tRNS)
trans_values - graylevel or color sample values of
the single transparent color for
non-paletted images (PNG_INFO_tRNS)
@@ -1493,6 +1516,10 @@ into the info_ptr is returned for any complex types.
string for unknown).
text_ptr[i].lang_key - keyword in UTF-8
(empty string for unknown).
+ Note that the itxt_length, lang, and lang_key
+ members of the text_ptr structure only exist
+ when the library is built with iTXt chunk support.
+
num_text - number of comments (same as
num_comments; you can put NULL here
to avoid the duplication)
@@ -1672,6 +1699,43 @@ things.
As of libpng version 1.2.9, png_set_expand_gray_1_2_4_to_8() was
added. It expands the sample depth without changing tRNS to alpha.
+As of libpng version 1.2.44, not all possible expansions are supported.
+
+In the following table, the 01 means grayscale with depth<8, 31 means
+indexed with depth<8, other numerals represent the color type, "T" means
+the tRNS chunk is present, A means an alpha channel is present, and O
+means tRNS or alpha is present but all pixels in the image are opaque.
+
+ FROM 01 31 0 0T 0O 2 2T 2O 3 3T 3O 4A 4O 6A 6O
+ TO
+ 01 -
+ 31 -
+ 0 1 -
+ 0T -
+ 0O -
+ 2 GX -
+ 2T -
+ 2O -
+ 3 1 -
+ 3T -
+ 3O -
+ 4A T -
+ 4O -
+ 6A GX TX TX -
+ 6O GX TX -
+
+Within the matrix,
+ "-" means the transformation is not supported.
+ "X" means the transformation is obtained by png_set_expand().
+ "1" means the transformation is obtained by
+ png_set_expand_gray_1_2_4_to_8
+ "G" means the transformation is obtained by
+ png_set_gray_to_rgb().
+ "P" means the transformation is obtained by
+ png_set_expand_palette_to_rgb().
+ "T" means the transformation is obtained by
+ png_set_tRNS_to_alpha().
+
PNG can have files with 16 bits per channel. If you only can handle
8 bits per channel, this will strip the pixels down to 8 bit.
@@ -1695,6 +1759,15 @@ images) is fully transparent, with
png_set_invert_alpha(png_ptr);
+The PNG format only supports pixels with postmultiplied alpha.
+If you want to replace the pixels, after reading them, with pixels
+that have premultiplied color samples, you can do this with
+
+ png_set_premultiply_alpha(png_ptr);
+
+If you do this, any input with a tRNS chunk will be expanded to
+have an alpha channel.
+
PNG files pack pixels of bit depths 1, 2, and 4 into bytes as small as
they can, resulting in, for example, 8 pixels per byte for 1 bit
files. This code expands to 1 pixel per byte without changing the
@@ -1705,10 +1778,10 @@ values of the pixels:
PNG files have possible bit depths of 1, 2, 4, 8, and 16. All pixels
stored in a PNG image have been "scaled" or "shifted" up to the next
-higher possible bit depth (e.g. from 5 bits/sample in the range [0,31] to
-8 bits/sample in the range [0, 255]). However, it is also possible to
-convert the PNG pixel data back to the original bit depth of the image.
-This call reduces the pixels back down to the original bit depth:
+higher possible bit depth (e.g. from 5 bits/sample in the range [0,31]
+to 8 bits/sample in the range [0, 255]). However, it is also possible
+to convert the PNG pixel data back to the original bit depth of the
+image. This call reduces the pixels back down to the original bit depth:
png_color_8p sig_bit;
@@ -2155,12 +2228,11 @@ point to libpng-allocated storage with the following function:
This function may be safely called when the relevant storage has
already been freed, or has not yet been allocated, or was allocated
-by the user and not by libpng, and will in those
-cases do nothing. The "seq" parameter is ignored if only one item
-of the selected data type, such as PLTE, is allowed. If "seq" is not
--1, and multiple items are allowed for the data type identified in
-the mask, such as text or sPLT, only the n'th item in the structure
-is freed, where n is "seq".
+by the user and not by libpng, and will in those cases do nothing.
+The "seq" parameter is ignored if only one item of the selected data
+type, such as PLTE, is allowed. If "seq" is not -1, and multiple items
+are allowed for the data type identified in the mask, such as text or
+sPLT, only the n'th item in the structure is freed, where n is "seq".
The default behavior is only to free data that was allocated internally
by libpng. This can be changed, so that libpng will not free the data,
@@ -2199,8 +2271,8 @@ if you transfer responsibility for free'ing text_ptr from libpng to your
application, your application must not separately free those members.
The png_free_data() function will turn off the "valid" flag for anything
-it frees. If you need to turn the flag off for a chunk that was freed by your
-application instead of by libpng, you can use
+it frees. If you need to turn the flag off for a chunk that was freed by
+your application instead of by libpng, you can use
png_set_invalid(png_ptr, info_ptr, mask);
mask - identifies the chunks to be made invalid,
@@ -2510,8 +2582,8 @@ the filter method, for which the only valid values are 0 (as of the
July 1999 PNG specification, version 1.2) or 64 (if you are writing
a PNG datastream that is to be embedded in a MNG datastream). The third
parameter is a flag that indicates which filter type(s) are to be tested
-for each scanline. See the PNG specification for details on the specific filter
-types.
+for each scanline. See the PNG specification for details on the specific
+filter types.
/* turn on or off filtering, and/or choose
@@ -2679,8 +2751,8 @@ width, height, bit_depth, and color_type must be the same in each call.
png_set_tRNS(png_ptr, info_ptr, trans, num_trans,
trans_values);
- trans - array of transparent entries for
- palette (PNG_INFO_tRNS)
+ trans - array of transparent
+ entries for palette (PNG_INFO_tRNS)
trans_values - graylevel or color sample values
(in order red, green, blue) of the
single transparent color for
@@ -2720,6 +2792,10 @@ width, height, bit_depth, and color_type must be the same in each call.
empty for unknown).
text_ptr[i].translated_keyword - keyword in UTF-8 (NULL
or empty for unknown).
+ Note that the itxt_length, lang, and lang_key
+ members of the text_ptr structure only exist
+ when the library is built with iTXt chunk support.
+
num_text - number of comments
png_set_sPLT(png_ptr, info_ptr, &palette_ptr,
@@ -2925,10 +3001,10 @@ this with a call to png_write_info().
Note that there is one transformation you may need to do before
png_write_info(). In PNG files, the alpha channel in an image is the
-level of opacity. If your data is supplied as a level of
-transparency, you can invert the alpha channel before you write it, so
-that 0 is fully transparent and 255 (in 8-bit or paletted images) or
-65535 (in 16-bit images) is fully opaque, with
+level of opacity. If your data is supplied as a level of transparency,
+you can invert the alpha channel before you write it, so that 0 is
+fully transparent and 255 (in 8-bit or paletted images) or 65535
+(in 16-bit images) is fully opaque, with
png_set_invert_alpha(png_ptr);
@@ -3115,14 +3191,13 @@ a single row_pointer instead of an array of row_pointers:
png_write_row(png_ptr, row_pointer);
-When the file is interlaced, things can get a good deal more
-complicated. The only currently (as of the PNG Specification
-version 1.2, dated July 1999) defined interlacing scheme for PNG files
-is the "Adam7" interlace scheme, that breaks down an
-image into seven smaller images of varying size. libpng will build
-these images for you, or you can do them yourself. If you want to
-build them yourself, see the PNG specification for details of which
-pixels to write when.
+When the file is interlaced, things can get a good deal more complicated.
+The only currently (as of the PNG Specification version 1.2, dated July
+1999) defined interlacing scheme for PNG files is the "Adam7" interlace
+scheme, that breaks down an image into seven smaller images of varying
+size. libpng will build these images for you, or you can do them
+yourself. If you want to build them yourself, see the PNG specification
+for details of which pixels to write when.
If you don't want libpng to handle the interlacing details, just
use png_set_interlace_handling() and call png_write_rows() the
@@ -3134,17 +3209,17 @@ writing any rows:
number_of_passes =
png_set_interlace_handling(png_ptr);
-This will return the number of passes needed. Currently, this
-is seven, but may change if another interlace type is added.
+This will return the number of passes needed. Currently, this is seven,
+but may change if another interlace type is added.
Then write the complete image number_of_passes times.
png_write_rows(png_ptr, row_pointers,
number_of_rows);
-As some of these rows are not used, and thus return immediately,
-you may want to read about interlacing in the PNG specification,
-and only update the rows that are actually used.
+As some of these rows are not used, and thus return immediately, you may
+want to read about interlacing in the PNG specification, and only update
+the rows that are actually used.
.SS Finishing a sequential write
@@ -3177,15 +3252,14 @@ point to libpng-allocated storage with the following function:
This function may be safely called when the relevant storage has
already been freed, or has not yet been allocated, or was allocated
-by the user and not by libpng, and will in those
-cases do nothing. The "seq" parameter is ignored if only one item
-of the selected data type, such as PLTE, is allowed. If "seq" is not
--1, and multiple items are allowed for the data type identified in
-the mask, such as text or sPLT, only the n'th item in the structure
-is freed, where n is "seq".
-
-If you allocated data such as a palette that you passed
-in to libpng with png_set_*, you must not free it until just before the call to
+by the user and not by libpng, and will in those cases do nothing.
+The "seq" parameter is ignored if only one item of the selected data
+type, such as PLTE, is allowed. If "seq" is not -1, and multiple items
+are allowed for the data type identified in the mask, such as text or
+sPLT, only the n'th item in the structure is freed, where n is "seq".
+
+If you allocated data such as a palette that you passed in to libpng
+with png_set_*, you must not free it until just before the call to
png_destroy_write_struct().
The default behavior is only to free data that was allocated internally
@@ -3251,16 +3325,18 @@ goes through callbacks that are user-settable. The default routines are
in pngmem.c, pngrio.c, pngwio.c, and pngerror.c, respectively. To change
these functions, call the appropriate png_set_*_fn() function.
-Memory allocation is done through the functions png_malloc()
-and png_free(). These currently just call the standard C functions. If
-your pointers can't access more then 64K at a time, you will want to set
-MAXSEG_64K in zlib.h. Since it is unlikely that the method of handling
-memory allocation on a platform will change between applications, these
-functions must be modified in the library at compile time. If you prefer
-to use a different method of allocating and freeing data, you can use
-png_create_read_struct_2() or png_create_write_struct_2() to register
-your own functions as described above.
-These functions also provide a void pointer that can be retrieved via
+Memory allocation is done through the functions png_malloc(), png_calloc(),
+and png_free(). These currently just call the standard C functions.
+png_calloc() calls png_malloc() and then png_memset() to clear the newly
+allocated memory to zero. If your pointers can't access more then 64K
+at a time, you will want to set MAXSEG_64K in zlib.h. Since it is
+unlikely that the method of handling memory allocation on a platform
+will change between applications, these functions must be modified in
+the library at compile time. If you prefer to use a different method
+of allocating and freeing data, you can use png_create_read_struct_2() or
+png_create_write_struct_2() to register your own functions as described
+above. These functions also provide a void pointer that can be retrieved
+via
mem_ptr=png_get_mem_ptr(png_ptr);
@@ -3352,10 +3428,10 @@ The motivation behind using setjmp() and longjmp() is the C++ throw and
catch exception handling methods. This makes the code much easier to write,
as there is no need to check every return code of every function call.
However, there are some uncertainties about the status of local variables
-after a longjmp, so the user may want to be careful about doing anything after
-setjmp returns non-zero besides returning itself. Consult your compiler
-documentation for more details. For an alternative approach, you may wish
-to use the "cexcept" facility (see http://cexcept.sourceforge.net).
+after a longjmp, so the user may want to be careful about doing anything
+after setjmp returns non-zero besides returning itself. Consult your
+compiler documentation for more details. For an alternative approach, you
+may wish to use the "cexcept" facility (see http://cexcept.sourceforge.net).
.SS Custom chunks
@@ -3367,15 +3443,14 @@ library code itself needs to know about interactions between your
chunk and existing `intrinsic' chunks.
If you need to write a new intrinsic chunk, first read the PNG
-specification. Acquire a first level of
-understanding of how it works. Pay particular attention to the
-sections that describe chunk names, and look at how other chunks were
-designed, so you can do things similarly. Second, check out the
-sections of libpng that read and write chunks. Try to find a chunk
-that is similar to yours and use it as a template. More details can
-be found in the comments inside the code. It is best to handle unknown
-chunks in a generic method, via callback functions, instead of by
-modifying libpng functions.
+specification. Acquire a first level of understanding of how it works.
+Pay particular attention to the sections that describe chunk names,
+and look at how other chunks were designed, so you can do things
+similarly. Second, check out the sections of libpng that read and
+write chunks. Try to find a chunk that is similar to yours and use
+it as a template. More details can be found in the comments inside
+the code. It is best to handle unknown chunks in a generic method,
+via callback functions, instead of by modifying libpng functions.
If you wish to write your own transformation for the data, look through
the part of the code that does the transformations, and check out some of
@@ -3552,14 +3627,14 @@ off en masse with compiler directives that define
PNG_NO_READ[or WRITE]_TRANSFORMS, or PNG_NO_READ[or WRITE]_ANCILLARY_CHUNKS,
or all four,
along with directives to turn on any of the capabilities that you do
-want. The PNG_NO_READ[or WRITE]_TRANSFORMS directives disable
-the extra transformations but still leave the library fully capable of reading
-and writing PNG files with all known public chunks
-Use of the PNG_NO_READ[or WRITE]_ANCILLARY_CHUNKS directive
-produces a library that is incapable of reading or writing ancillary chunks.
-If you are not using the progressive reading capability, you can
-turn that off with PNG_NO_PROGRESSIVE_READ (don't confuse
-this with the INTERLACING capability, which you'll still have).
+want. The PNG_NO_READ[or WRITE]_TRANSFORMS directives disable the extra
+transformations but still leave the library fully capable of reading
+and writing PNG files with all known public chunks. Use of the
+PNG_NO_READ[or WRITE]_ANCILLARY_CHUNKS directive produces a library
+that is incapable of reading or writing ancillary chunks. If you are
+not using the progressive reading capability, you can turn that off
+with PNG_NO_PROGRESSIVE_READ (don't confuse this with the INTERLACING
+capability, which you'll still have).
All the reading and writing specific code are in separate files, so the
linker should only grab the files it needs. However, if you want to
@@ -3694,6 +3769,9 @@ accomplish this, the functions png_create_read_struct_2(),
png_create_write_struct_2(), png_set_mem_fn(), png_get_mem_ptr(),
png_malloc_default(), and png_free_default() were added.
+Support for the iTXt chunk has been enabled by default as of
+version 1.2.41.
+
Support for certain MNG features was enabled.
Support for numbered error messages was added. However, we never got
@@ -3748,14 +3826,50 @@ selection of assembler code features:
We replaced all of these functions with simple stubs in libpng-1.2.20,
when the Intel assembler code was removed due to a licensing issue.
+These macros are deprecated:
+
+ PNG_READ_TRANSFORMS_NOT_SUPPORTED
+ PNG_PROGRESSIVE_READ_NOT_SUPPORTED
+ PNG_NO_SEQUENTIAL_READ_SUPPORTED
+ PNG_WRITE_TRANSFORMS_NOT_SUPPORTED
+ PNG_READ_ANCILLARY_CHUNKS_NOT_SUPPORTED
+ PNG_WRITE_ANCILLARY_CHUNKS_NOT_SUPPORTED
+
+They have been replaced, respectively, by:
+
+ PNG_NO_READ_TRANSFORMS
+ PNG_NO_PROGRESSIVE_READ
+ PNG_NO_SEQUENTIAL_READ
+ PNG_NO_WRITE_TRANSFORMS
+ PNG_NO_READ_ANCILLARY_CHUNKS
+ PNG_NO_WRITE_ANCILLARY_CHUNKS
+
+PNG_MAX_UINT was replaced with PNG_UINT_31_MAX. It has been
+deprecated since libpng-1.0.16 and libpng-1.2.6.
+
+The function
+ png_check_sig(sig, num)
+was replaced with
+ !png_sig_cmp(sig, 0, num)
+It has been deprecated since libpng-0.90.
+
+The function
+ png_set_gray_1_2_4_to_8()
+which also expands tRNS to alpha was replaced with
+ png_set_expand_gray_1_2_4_to_8()
+which does not. It has been deprecated since libpng-1.0.18 and 1.2.9.
+
.SH IX. (Omitted)
+
.SH X. Detecting libpng
The png_get_io_ptr() function has been present since libpng-0.88, has never
changed, and is unaffected by conditional compilation macros. It is the
best choice for use in configure scripts for detecting the presence of any
-libpng version since 0.88.
+libpng version since 0.88. In an autoconf "configure.in" you could use
+
+ AC_CHECK_LIB(png, png_get_io_ptr, ...
.SH XI. Source code repository
@@ -3800,6 +3914,15 @@ We use 3-space indentation, except for continued statements which
are usually indented the same as the first line of the statement
plus four more spaces.
+For macro definitions we use 2-space indentation, always leaving the "#"
+in the first column.
+
+ #ifndef PNG_NO_FEATURE
+ # ifndef PNG_FEATURE_SUPPORTED
+ # define PNG_FEATURE_SUPPORTED
+ # endif
+ #endif
+
Comments appear with the leading "/*" at the same indentation as
the statement that follows the comment:
@@ -3832,7 +3955,10 @@ exported functions are marked with PNGAPI:
body;
}
-The prototypes for all exported functions appear in png.h.
+The prototypes for all exported functions appear in png.h,
+above the comment that says
+
+ /* Maintainer: Put new public prototypes here ... */
We mark all non-exported functions with "/* PRIVATE */"":
@@ -3842,9 +3968,12 @@ We mark all non-exported functions with "/* PRIVATE */"":
body;
}
-The prototypes for non-exported functions can appear in
+The prototypes for non-exported functions (except for those in
+pngtest) appear in
the PNG_INTERNAL section of png.h
-or in the file where the function is located.
+above the comment that says
+
+ /* Maintainer: Put new private prototypes here ^ and in libpngpf.3 */
The names of all exported functions and variables begin
with "png_", and all publicly visible C preprocessor
@@ -3858,23 +3987,26 @@ cast, nor do we put one between a function name and the
left parenthesis that follows it:
for (i = 2; i > 0; --i)
- x[i] = a(x) + (int)b;
+ y[i] = a(x) + (int)b;
We prefer #ifdef and #ifndef to #if defined() and if !defined()
when there is only one macro being tested.
-Other rules can be inferred by inspecting the libpng
-source.
+We do not use the TAB character for indentation in the C sources.
+
+Lines do not exceed 80 characters.
+
+Other rules can be inferred by inspecting the libpng source.
.SH XIII. Y2K Compliance in libpng
-July 16, 2009
+June 26, 2010
Since the PNG Development group is an ad-hoc body, we can't make
an official declaration.
This is your unofficial assurance that libpng from version 0.71 and
-upward through 1.2.38 are Y2K compliant. It is my belief that earlier
+upward through 1.2.44 are Y2K compliant. It is my belief that earlier
versions were also Y2K compliant.
Libpng only has three year fields. One is a 2-byte unsigned integer that
@@ -4149,6 +4281,32 @@ the first widely used release:
1.2.38rc01-03 13 10238 12.so.0.38[.0]
1.0.47 10 10047 10.so.0.47[.0]
1.2.38 13 10238 12.so.0.38[.0]
+ 1.2.39beta01-05 13 10239 12.so.0.39[.0]
+ 1.2.39rc01 13 10239 12.so.0.39[.0]
+ 1.0.48 10 10048 10.so.0.48[.0]
+ 1.2.39 13 10239 12.so.0.39[.0]
+ 1.2.40beta01 13 10240 12.so.0.40[.0]
+ 1.2.40rc01 13 10240 12.so.0.40[.0]
+ 1.0.49 10 10049 10.so.0.49[.0]
+ 1.2.40 13 10240 12.so.0.40[.0]
+ 1.0.50 10 10050 10.so.0.50[.0]
+ 1.2.41beta01-18 13 10241 12.so.0.41[.0]
+ 1.0.51rc01 10 10051 10.so.0.51[.0]
+ 1.2.41rc01-03 13 10241 12.so.0.41[.0]
+ 1.0.51 10 10051 10.so.0.51[.0]
+ 1.2.41 13 10241 12.so.0.41[.0]
+ 1.2.42beta01-02 13 10242 12.so.0.42[.0]
+ 1.2.42rc01-05 13 10242 12.so.0.42[.0]
+ 1.0.52 10 10052 10.so.0.52[.0]
+ 1.2.42 13 10242 12.so.0.42[.0]
+ 1.2.43beta01-05 13 10243 12.so.0.43[.0]
+ 1.0.53rc01-02 10 10053 10.so.0.53[.0]
+ 1.2.43rc01-02 13 10243 12.so.0.43[.0]
+ 1.0.53 10 10053 10.so.0.53[.0]
+ 1.2.43 13 10243 12.so.0.43[.0]
+ 1.2.44beta01-03 13 10244 12.so.0.44[.0]
+ 1.2.44rc01-03 13 10244 12.so.0.44[.0]
+ 1.2.44 13 10244 12.so.0.44[.0]
Henceforth the source version will match the shared-library minor
and patch numbers; the shared-library major version number will be
@@ -4204,7 +4362,7 @@ possible without all of you.
Thanks to Frank J. T. Wojcik for helping with the documentation.
-Libpng version 1.2.38 - July 16, 2009:
+Libpng version 1.2.44 - June 26, 2010:
Initially created in 1995 by Guy Eric Schalnat, then of Group 42, Inc.
Currently maintained by Glenn Randers-Pehrson (glennrp at users.sourceforge.net).
@@ -4227,7 +4385,7 @@ this sentence.
This code is released under the libpng license.
-libpng versions 1.2.6, August 15, 2004, through 1.2.38, July 16, 2009, are
+libpng versions 1.2.6, August 15, 2004, through 1.2.44, June 26, 2010, are
Copyright (c) 2004,2006-2008 Glenn Randers-Pehrson, and are
distributed according to the same disclaimer and license as libpng-1.2.5
with the following individual added to the list of Contributing Authors
@@ -4326,7 +4484,7 @@ certification mark of the Open Source Initiative.
Glenn Randers-Pehrson
glennrp at users.sourceforge.net
-July 16, 2009
+June 26, 2010
.\" end of man page