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Diffstat (limited to 'contrib/gregbook/readpng2.c')
| -rw-r--r-- | contrib/gregbook/readpng2.c | 645 |
1 files changed, 0 insertions, 645 deletions
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); -} |