diff options
| -rw-r--r-- | CHANGES | 18 | ||||
| -rw-r--r-- | README | 23 | ||||
| -rw-r--r-- | example.c | 120 | ||||
| -rw-r--r-- | libpng.txt | 51 | ||||
| -rw-r--r-- | makefile.dec | 68 | ||||
| -rw-r--r-- | makefile.elf | 10 | ||||
| -rw-r--r-- | png.c | 154 | ||||
| -rw-r--r-- | png.h | 238 | ||||
| -rw-r--r-- | pngconf.h | 225 | ||||
| -rw-r--r-- | pngerror.c | 63 | ||||
| -rw-r--r-- | pngget.c | 52 | ||||
| -rw-r--r-- | pngmem.c | 25 | ||||
| -rw-r--r-- | pngpread.c | 59 | ||||
| -rw-r--r-- | pngread.c | 100 | ||||
| -rw-r--r-- | pngrio.c | 27 | ||||
| -rw-r--r-- | pngrtran.c | 200 | ||||
| -rw-r--r-- | pngrutil.c | 201 | ||||
| -rw-r--r-- | pngset.c | 74 | ||||
| -rw-r--r-- | pngtest.c | 50 | ||||
| -rw-r--r-- | pngtrans.c | 14 | ||||
| -rw-r--r-- | pngwio.c | 27 | ||||
| -rw-r--r-- | pngwrite.c | 90 | ||||
| -rw-r--r-- | pngwtran.c | 43 | ||||
| -rw-r--r-- | pngwutil.c | 128 |
24 files changed, 1297 insertions, 763 deletions
@@ -167,3 +167,21 @@ version 0.96 [May, 1997] added read of CRC after IEND chunk for embedded PNGs (Laszlo Nyul) added typecasts to quiet compiler errors added more debugging info +version 1.00 [not distributed, but Andreas handed off to G&G] + skipped version 1.00 to avoid potential problems with shared libraries + created with version 0.89 + removed PNG_USE_OWN_CRC capability + relocated png_set_crc_action from pngrutil.c to pngrtran.c + fixed typecasts of "new_key" etc. + added RFC 1152 date support +version 1.00.97 [Dec 1997] + fixed bug in gamma handling of 4-bit grayscale + added more typecasts. 65536L becomes (png_uint_32)65536L, etc. + minor corrections in libpng.txt + added simple sRGB support + make it simpler to do conditional compiling + fixed memory leak in pngwrite.c (free info_ptr->text) + added more conditions for png_do_background, to avoid changing + black pixels to background when a background is supplied and + no pixels are transparent + include stdio.h in pngconf.h even when PNG_NO_STDIO is defined. @@ -1,9 +1,16 @@ -README for libpng 0.96 +README for libpng 1.10 -This is the sixth (and hopefully last) beta release of libpng 1.0. -The changes from libpng-0.90 include bug fixes, a C++ wrapper for -png.h, some additions to the API, as well as internal changes to -the library. See "CHANGES" for a detailed list of differences. +This first official release of libpng. Don't let the fact that +it's the first release fool you. The libpng library has been in +extensive use and testing for about two years. However, it's +finally gotten to the stage where there haven't been significant +changes to the API in some time, and people have a bad feeling about +libraries with versions < 1.0. + +Note that the version number is 1.10 to avoid potential problems +with shared libraries created for Linux ELF under version 0.89, +which mistakenly used 1.0.89 as the library version number in +false anticipation of an imminent 1.0 release. **** Note that some of the changes to the png_info structure render this @@ -19,6 +26,12 @@ access to info_ptr. These functions are the png_set_<chunk> and png_get_<chunk> functions. These functions should be used when accessing/storing the info_struct data, rather than manipulating it directly, to avoid such problems in the future. + +It is important to note that the APIs do not make current programs +which access the info struct directly incompatible with the new +library. However, it is strongly suggested that new programs use +the new APIs (as shown in example.c), and older programs be converted +to the new format, to facilitate upgrades in the future. **** Additions since 0.90 include the ability to compile libpng as a @@ -1,36 +1,36 @@ /* example.c - an example of using libpng */ /* This is an example of how to use libpng to read and write PNG files. - The file libpng.txt is much more verbose then this. If you have not - read it, do so first. This was designed to be a starting point of an - implementation. This is not officially part of libpng, and therefore - does not require a copyright notice. - - This file does not currently compile, because it is missing certain - parts, like allocating memory to hold an image. You will have to - supply these parts to get it to compile. For an example of a minimal - working PNG reader/writer, see pngtest.c, included in this distribution. -*/ + * The file libpng.txt is much more verbose then this. If you have not + * read it, do so first. This was designed to be a starting point of an + * implementation. This is not officially part of libpng, and therefore + * does not require a copyright notice. + * + * This file does not currently compile, because it is missing certain + * parts, like allocating memory to hold an image. You will have to + * supply these parts to get it to compile. For an example of a minimal + * working PNG reader/writer, see pngtest.c, included in this distribution. + */ #include <png.h> /* Check to see if a file is a PNG file using png_check_sig(). Returns - non-zero if the image is a PNG, and 0 if it isn't a PNG. - - If this call is successful, and you are going to keep the file open, - you should call png_set_sig_bytes(png_ptr, PNG_BYTES_TO_CHECK); once - you have created the png_ptr, so that libpng knows your application - has read that many bytes from the start of the file. Make sure you - don't call png_set_sig_bytes() with more than 8 bytes read or give it - an incorrect number of bytes read, or you will either have read too - many bytes (your fault), or you are telling libpng to read the wrong - number of magic bytes (also your fault). - - Many applications already read the first 2 or 4 bytes from the start - of the image to determine the file type, so it would be easiest just - to pass the bytes to png_check_sig() or even skip that if you know - you have a PNG file, and call png_set_sig_bytes(). -*/ + * non-zero if the image is a PNG, and 0 if it isn't a PNG. + * + * If this call is successful, and you are going to keep the file open, + * you should call png_set_sig_bytes(png_ptr, PNG_BYTES_TO_CHECK); once + * you have created the png_ptr, so that libpng knows your application + * has read that many bytes from the start of the file. Make sure you + * don't call png_set_sig_bytes() with more than 8 bytes read or give it + * an incorrect number of bytes read, or you will either have read too + * many bytes (your fault), or you are telling libpng to read the wrong + * number of magic bytes (also your fault). + * + * Many applications already read the first 2 or 4 bytes from the start + * of the image to determine the file type, so it would be easiest just + * to pass the bytes to png_check_sig() or even skip that if you know + * you have a PNG file, and call png_set_sig_bytes(). + */ #define PNG_BYTES_TO_CHECK 4 int check_if_png(char *file_name, FILE **fp) { @@ -49,10 +49,11 @@ int check_if_png(char *file_name, FILE **fp) } /* Read a PNG file. You may want to return an error code if the read - fails (depending upon the failure). There are two "prototypes" given - here - one where we are given the filename, and we need to open the - file, and the other where we are given an open file (possibly with - some or all of the magic bytes read - see comments above). */ + * fails (depending upon the failure). There are two "prototypes" given + * here - one where we are given the filename, and we need to open the + * file, and the other where we are given an open file (possibly with + * some or all of the magic bytes read - see comments above). + */ **** prototype 1 **** void read_png(char *file_name) /* We need to open the file */ { @@ -118,7 +119,8 @@ void read_png(FILE *fp, unsigned int sig_read) /* file is already open */ **** PNG file I/O method 2 **** /* If you are using replacement read functions, instead of calling - * png_init_io() here you would call */ + * png_init_io() here you would call: + */ png_set_read_fn(png_ptr, (void *)user_io_ptr, user_read_fn); /* where user_io_ptr is a structure you want available to the callbacks */ **** Use only one I/O method! **** @@ -143,29 +145,31 @@ void read_png(FILE *fp, unsigned int sig_read) /* file is already open */ /* tell libpng to strip 16 bit/color files down to 8 bits/color */ png_set_strip_16(png_ptr); - /* strip alpha bytes from the input data without combining with th - * background (not recommended) */ + /* Strip alpha bytes from the input data without combining with th + * background (not recommended). + */ png_set_strip_alpha(png_ptr); - /* extract multiple pixels with bit depths of 1, 2, and 4 from a single + /* Extract multiple pixels with bit depths of 1, 2, and 4 from a single * byte into separate bytes (useful for paletted and grayscale images). */ png_set_packing(png_ptr); - /* change the order of packed pixels to least significant bit first + /* Change the order of packed pixels to least significant bit first * (not useful if you are using png_set_packing). */ png_set_packswap(png_ptr); - /* expand paletted colors into true RGB triplets */ + /* Expand paletted colors into true RGB triplets */ if (color_type == PNG_COLOR_TYPE_PALETTE) png_set_expand(png_ptr); - /* expand grayscale images to the full 8 bits from 1, 2, or 4 bits/pixel */ + /* Expand grayscale images to the full 8 bits from 1, 2, or 4 bits/pixel */ if (color_type == PNG_COLOR_TYPE_GRAY && bit_depth < 8) png_set_expand(png_ptr); - /* expand paletted or RGB images with transparency to full alpha channels - * so the data will be available as RGBA quartets */ + /* Expand paletted or RGB images with transparency to full alpha channels + * so the data will be available as RGBA quartets. + */ if (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS)) png_set_expand(png_ptr); @@ -207,13 +211,17 @@ void read_png(FILE *fp, unsigned int sig_read) /* file is already open */ * by the user at run time by the user. It is strongly suggested that * your application support gamma correction. */ - if (png_get_gAMA(png_ptr, info_ptr, &image_gamma); - png_set_gamma(png_ptr, screen_gamma, image_gamma); - else - png_set_gamma(png_ptr, screen_gamma, 0.45); + if (png_get_sRGB(png_ptr, info_ptr, &srgb_intent) + png_set_sRGB(png_ptr, srgb_intent, 0); + else + if (png_get_gAMA(png_ptr, info_ptr, &image_gamma) + png_set_gamma(png_ptr, screen_gamma, image_gamma); + else + png_set_gamma(png_ptr, screen_gamma, 0.45); /* Dither RGB files down to 8 bit palette or reduce palettes - to the number of colors available on your screen */ + * to the number of colors available on your screen. + */ if (color_type & PNG_COLOR_MASK_COLOR) { png_uint_32 num_palette; @@ -269,19 +277,19 @@ void read_png(FILE *fp, unsigned int sig_read) /* file is already open */ /* Turn on interlace handling. REQUIRED if you are not using * png_read_image(). To see how to handle interlacing passes, - * see the png_read_row() method below. + * see the png_read_row() method below: */ number_passes = png_set_interlace_handling(png_ptr); - /* optional call to gamma correct and add the background to the palette + /* Optional call to gamma correct and add the background to the palette * and update info structure. REQUIRED if you are expecting libpng to * update the palette for you (ie you selected such a transform above). */ png_read_update_info(png_ptr, info_ptr); - /* allocate the memory to hold the image using the fields of info_ptr. */ + /* Allocate the memory to hold the image using the fields of info_ptr. */ - /* the easiest way to read the image */ + /* The easiest way to read the image: */ png_bytep row_pointers[height]; for (row = 0; row < height; row++) @@ -294,7 +302,7 @@ void read_png(FILE *fp, unsigned int sig_read) /* file is already open */ png_read_image(png_ptr, row_pointers); **** Read the image one or more scanlines at a time **** - /* the other way to read images - deal with interlacing */ + /* The other way to read images - deal with interlacing: */ for (pass = 0; pass < number_passes; pass++) { @@ -552,7 +560,8 @@ void write_png(char *file_name, ... other image information ...) /* Optional gamma chunk is strongly suggested if you have any guess - * as to the correct gamma of the image. */ + * as to the correct gamma of the image. + */ png_set_gAMA(png_ptr, info_ptr, gamma); /* Optionally write comments into the image */ @@ -568,6 +577,8 @@ void write_png(char *file_name, ... other image information ...) png_set_text(png_ptr, info_ptr, text_ptr, 2); /* other optional chunks like cHRM, bKGD, tRNS, tIME, oFFs, pHYs, */ + /* note that if sRGB is present the cHRM chunk must be ignored + * on read and must be written in accordance with the sRGB profile */ /* Write the file header information. REQUIRED */ png_write_info(png_ptr, info_ptr); @@ -579,13 +590,15 @@ void write_png(char *file_name, ... other image information ...) */ /* set up the transformations you want. Note that these are - * all optional. Only call them if you want them. */ + * all optional. Only call them if you want them. + */ /* invert monocrome pixels */ png_set_invert(png_ptr); /* Shift the pixels up to a legal bit depth and fill in - * as appropriate to correctly scale the image */ + * as appropriate to correctly scale the image. + */ png_set_shift(png_ptr, &sig_bit); /* pack pixels into bytes */ @@ -595,7 +608,8 @@ void write_png(char *file_name, ... other image information ...) png_set_swap_alpha(png_ptr); /* Get rid of filler (OR ALPHA) bytes, pack XRGB/RGBX/ARGB/RGBA into - * RGB (4 channels -> 3 channels). The second parameter is not used. */ + * RGB (4 channels -> 3 channels). The second parameter is not used. + */ png_set_filler(png_ptr, 0, PNG_FILLER_BEFORE); /* flip BGR pixels to RGB */ diff --git a/libpng.txt b/libpng.txt index a603c3a4c..76c2d6fb4 100644 --- a/libpng.txt +++ b/libpng.txt @@ -1,10 +1,13 @@ libpng.txt - a description on how to use and modify libpng - libpng 1.0 beta 5 - version 0.95 + libpng version 1.00 version 0.97 + + based on: + + libpng version 1.00 version 0.96 Updated and distributed by Andreas Dilger <adilger@enel.ucalgary.ca>, Copyright (c) 1996, 1997 Andreas Dilger - March 15, 1997 - based on: + May 28, 1997 libpng 1.0 beta 2 - version 0.88 For conditions of distribution and use, see copyright notice in png.h @@ -27,11 +30,18 @@ will need. Libpng was written as a companion to the PNG specification, as a way to reduce the amount of time and effort it takes to support the PNG -file format in application programs. Most users will not have to -modify the library significantly; advanced users may want to modify it -more. All attempts were made to make it as complete as possible, -while keeping the code easy to understand. Currently, this library -only supports C. Support for other languages is being considered. +file format in application programs. The PNG specification is available +as RFC 2083 <ftp://ftp.uu.net/graphics/png/documents/> and as a +W3C Recommendation <http://www.w3.org/pub/WWW/TR/REC.png.html>. Some +additional chunks are described in the special-purpose public chunks +documents at <ftp://ftp.uu.net/graphics/png/documents/>. Other information +about PNG can be found at the PNG home page, <http://www.cdrom.com/pub/png/>. + +Most users will not have to modify the library significantly; advanced +users may want to modify it more. All attempts were made to make it as +complete as possible, while keeping the code easy to understand. +Currently, this library only supports C. Support for other languages +is being considered. Libpng has been designed to handle multiple sessions at one time, to be easily modifiable, to be portable to the vast majority of @@ -341,7 +351,7 @@ transparency information in a tRNS chunk. This is most useful on grayscale images with bit depths of 2 or 4 or if there is a multiple-image viewing application that wishes to treat all images in the same way. - if (color_type == PNG_COLOR_TYPE_PALETTE && bit_depth < 8) + if (color_type == PNG_COLOR_TYPE_PALETTE && bit_depth <= 8) png_set_expand(png_ptr); if (color_type == PNG_COLOR_TYPE_GRAY && bit_depth < 8) @@ -614,7 +624,7 @@ The first pass will return an image 1/8 as wide as the entire image (every 8th column starting in column 0) and 1/8 as high as the original (every 8th row starting in row 0), the second will be 1/8 as wide (starting in column 4) and 1/8 as high (also starting in row 0). The -third pass will be 1/4 as wide (every 4th pixel starting in row 0) and +third pass will be 1/4 as wide (every 4th pixel starting in column 0) and 1/8 as high (every 8th row starting in row 4), and the fourth pass will be 1/4 as wide and 1/4 as high (every 4th column starting in column 2, and every 4th row starting in row 0). The fifth pass will return an @@ -1013,7 +1023,8 @@ The keywords that are given in the PNG Specification are: Author Name of image's creator Description Description of image (possibly long) Copyright Copyright notice - Creation Time Time of original image creation + Creation Time Time of original image creation (usually + RFC 1123 format, see below) Software Software used to create the image Disclaimer Legal disclaimer Warning Warning of nature of content @@ -1050,6 +1061,20 @@ instead of your local time. Note that the year number is the full year (ie 1996, rather than 96 - PNG is year 2000 compliant!), and that months start with 1. +If you want to store the time of the original image creation, you should +use a plain tEXt chunk with the "Creation Time" keyword. This is +necessary because the "creation time" of a PNG image is somewhat vague, +depending on whether you mean the PNG file, the time the image was +created in a non-PNG format, a still photo from which the image was +scanned, or possibly the subject matter itself. In order to facilitate +machine-readable dates, it is recommended that the "Creation Time" +tEXt chunk use RFC 1123 format dates (eg 22 May 1997 18:07:10 GMT"), +although this isn't a requirement. Unlike the tIME chunk, the +"Creation Time" tEXt chunk is not expected to be automatically changed +by the software. To facilitate the use of RFC 1123 dates, a function +png_convert_to_rfc1152(png_timep) is provided to convert from PNG +time to an RFC 1152 format string. + You are now ready to write all the file information up to the actual image data. You do this with a call to png_write_info(). @@ -1307,8 +1332,8 @@ default function will be used, calling fprintf() and/or longjmp() if a problem is encountered. The replacement error functions should have parameters as follows: - void user_error_fn(png_struct png_ptr, png_const_charp error_msg); - void user_warning_fn(png_struct png_ptr, png_const_charp warning_msg); + void user_error_fn(png_structp png_ptr, png_const_charp error_msg); + void user_warning_fn(png_structp png_ptr, png_const_charp warning_msg); The motivation behind using setjmp() and longjmp() is the C++ throw and catch exception handling methods. This makes the code much easier to write, diff --git a/makefile.dec b/makefile.dec new file mode 100644 index 000000000..83260a74d --- /dev/null +++ b/makefile.dec @@ -0,0 +1,68 @@ +# makefile for libpng on DEC Alpha Unix +# Copyright (C) 1995 Guy Eric Schalnat, Group 42, Inc. +# For conditions of distribution and use, see copyright notice in png.h + +# Where the zlib library and include files are located +#ZLIBLIB=/usr/local/lib +#ZLIBINC=/usr/local/include +ZLIBLIB=../zlib +ZLIBINC=../zlib + +CC=cc +CFLAGS=-std -w1 -I$(ZLIBINC) -O # -g -DPNG_DEBUG=1 +LDFLAGS=-L. -L$(ZLIBLIB) -lpng -lz -lm + +#RANLIB=echo +RANLIB=ranlib + +# where make install puts libpng.a and png.h +prefix=/usr/local + +OBJS = png.o pngset.o pngget.o pngrutil.o pngtrans.o pngwutil.o \ + pngread.o pngrio.o pngwio.o pngwrite.o pngrtran.o \ + pngwtran.o pngmem.o pngerror.o pngpread.o + +all: libpng.a pngtest + +libpng.a: $(OBJS) + ar rc $@ $(OBJS) + $(RANLIB) $@ + +pngtest: pngtest.o libpng.a + $(CC) -o pngtest $(CCFLAGS) pngtest.o $(LDFLAGS) + +test: pngtest + ./pngtest + +install: libpng.a + -@mkdir $(prefix)/include + -@mkdir $(prefix)/lib + cp png.h $(prefix)/include + cp pngconf.h $(prefix)/include + chmod 644 $(prefix)/include/png.h + chmod 644 $(prefix)/include/pngconf.h + cp libpng.a $(prefix)/lib + chmod 644 $(prefix)/lib/libpng.a + +clean: + rm -f *.o libpng.a pngtest pngout.png + +# DO NOT DELETE THIS LINE -- make depend depends on it. + +png.o: png.h pngconf.h +pngerror.o: png.h pngconf.h +pngrio.o: png.h pngconf.h +pngwio.o: png.h pngconf.h +pngmem.o: png.h pngconf.h +pngset.o: png.h pngconf.h +pngget.o: png.h pngconf.h +pngread.o: png.h pngconf.h +pngrtran.o: png.h pngconf.h +pngrutil.o: png.h pngconf.h +pngtest.o: png.h pngconf.h +pngtrans.o: png.h pngconf.h +pngwrite.o: png.h pngconf.h +pngwtran.o: png.h pngconf.h +pngwutil.o: png.h pngconf.h +pngpread.o: png.h pngconf.h + diff --git a/makefile.elf b/makefile.elf index f63c35937..d949b3e23 100644 --- a/makefile.elf +++ b/makefile.elf @@ -13,14 +13,14 @@ ZLIBINC=../zlib WARNMORE=-Wwrite-strings -Wpointer-arith -Wshadow \ -Wmissing-declarations -Wtraditional -Wcast-align \ -Wstrict-prototypes -Wmissing-prototypes #-Wconversion -CFLAGS=-I$(ZLIBINC) -Wall -O2 -fPIC # $(WARNMORE) # -g -DPNG_DEBUG=3 +CFLAGS=-I$(ZLIBINC) -Wall -O3 -funroll-loops -malign-loops=2 -malign-functions=2 -fPIC #$(WARNMORE) -g -DPNG_DEBUG=5 LDFLAGS=-L. -Wl,-rpath,. -L$(ZLIBLIB) -Wl,-rpath,$(ZLIBLIB) -lpng -lz -lm RANLIB=ranlib #RANLIB=echo -PNGMAJ = 0 -PNGMIN = 96 +PNGMAJ = 1 +PNGMIN = 1.0 PNGVER = $(PNGMAJ).$(PNGMIN) # where make install puts libpng.a, libpng.so*, and png.h @@ -45,10 +45,10 @@ libpng.so.$(PNGMAJ): libpng.so.$(PNGVER) ln -sf libpng.so.$(PNGVER) libpng.so.$(PNGMAJ) libpng.so.$(PNGVER): $(OBJS) - gcc -shared -Wl,-soname,libpng.so.$(PNGMAJ) -o libpng.so.$(PNGVER) $(OBJS) + gcc -shared -Wl,-soname,libpng.so.$(PNGMAJ) $(OBJS) -o libpng.so.$(PNGVER) pngtest: pngtest.o libpng.so - $(CC) -o pngtest pngtest.o $(LDFLAGS) + $(CC) -o pngtest $(CCFLAGS) pngtest.o $(LDFLAGS) test: pngtest ./pngtest @@ -1,27 +1,29 @@ -/* png.c - location for general purpose png functions - - libpng 1.0 beta 6 - version 0.96 - For conditions of distribution and use, see copyright notice in png.h - Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. - Copyright (c) 1996, 1997 Andreas Dilger - May 12, 1997 - */ +/* png.c - location for general purpose libpng functions + * + * libpng 1.00.97 + * For conditions of distribution and use, see copyright notice in png.h + * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. + * Copyright (c) 1996, 1997 Andreas Dilger + * May 28, 1997 + */ #define PNG_INTERNAL #define PNG_NO_EXTERN #include "png.h" /* Version information for C files. This had better match the version - string defined in png.h */ -char png_libpng_ver[] = "0.95"; + * string defined in png.h. + */ +char png_libpng_ver[] = "1.00.97"; /* Place to hold the signiture string for a PNG file. */ png_byte FARDATA png_sig[8] = {137, 80, 78, 71, 13, 10, 26, 10}; -/* constant strings for known chunk types. If you need to add a chunk, - add a string holding the name here. If you want to make the code - portable to EBCDIC machines, use ASCII numbers, not characters. */ +/* Constant strings for known chunk types. If you need to add a chunk, + * add a string holding the name here. If you want to make the code + * portable to EBCDIC machines, use ASCII numbers, not characters. + */ png_byte FARDATA png_IHDR[5] = { 73, 72, 68, 82, '\0'}; png_byte FARDATA png_IDAT[5] = { 73, 68, 65, 84, '\0'}; png_byte FARDATA png_IEND[5] = { 73, 69, 78, 68, '\0'}; @@ -34,6 +36,7 @@ png_byte FARDATA png_oFFs[5] = {111, 70, 70, 115, '\0'}; png_byte FARDATA png_pCAL[5] = {112, 67, 65, 76, '\0'}; png_byte FARDATA png_pHYs[5] = {112, 72, 89, 115, '\0'}; png_byte FARDATA png_sBIT[5] = {115, 66, 73, 84, '\0'}; +png_byte FARDATA png_sRGB[5] = {115, 82, 71, 66, '\0'}; png_byte FARDATA png_tEXt[5] = {116, 69, 88, 116, '\0'}; png_byte FARDATA png_tIME[5] = {116, 73, 77, 69, '\0'}; png_byte FARDATA png_tRNS[5] = {116, 82, 78, 83, '\0'}; @@ -53,22 +56,20 @@ int FARDATA png_pass_ystart[] = {0, 0, 4, 0, 2, 0, 1}; /* offset to next interlace block in the y direction */ int FARDATA png_pass_yinc[] = {8, 8, 8, 4, 4, 2, 2}; -/* width of interlace block */ -/* this is not currently used - if you need it, uncomment it here and - in png.h +/* Width of interlace block. This is not currently used - if you need + * it, uncomment it here and in png.h int FARDATA png_pass_width[] = {8, 4, 4, 2, 2, 1, 1}; */ -/* height of interlace block */ -/* this is not currently used - if you need it, uncomment it here and - in png.h +/* Height of interlace block. This is not currently used - if you need + * it, uncomment it here and in png.h int FARDATA png_pass_height[] = {8, 8, 4, 4, 2, 2, 1}; */ -/* mask to determine which pixels are valid in a pass */ +/* Mask to determine which pixels are valid in a pass */ int FARDATA png_pass_mask[] = {0x80, 0x08, 0x88, 0x22, 0xaa, 0x55, 0xff}; -/* mask to determine which pixels to overwrite while displaying */ +/* Mask to determine which pixels to overwrite while displaying */ int FARDATA png_pass_dsp_mask[] = {0xff, 0x0f, 0xff, 0x33, 0xff, 0x55, 0xff}; @@ -113,8 +114,9 @@ png_sig_cmp(png_bytep sig, png_size_t start, png_size_t num_to_check) } /* (Obsolete) function to check signature bytes. It does not allow one - to check a partial signature. This function will be removed in the - future - use png_sig_cmp(). */ + * to check a partial signature. This function will be removed in the + * future - use png_sig_cmp(). + */ int png_check_sig(png_bytep sig, int num) { @@ -151,78 +153,19 @@ png_zfree(voidpf png_ptr, voidpf ptr) } /* Reset the CRC variable to 32 bits of 1's. Care must be taken - in case CRC is > 32 bits to leave the top bits 0. */ + * in case CRC is > 32 bits to leave the top bits 0. + */ void png_reset_crc(png_structp png_ptr) { - /* set CRC to all 1's */ -#ifdef PNG_USE_OWN_CRC - png_ptr->crc = 0xffffffffL; -#else png_ptr->crc = crc32(0, Z_NULL, 0); -#endif -} - -#ifdef PNG_USE_OWN_CRC -/* Table of CRCs of all 8-bit messages. By default, we use the tables made - by zlib, to save some memory. If you wish to png_malloc() this - table, turn this into a pointer, and png_malloc() it in make_crc_table(). - You may then want to hook it into png_struct and free it with the - destroy functions. Another alternative is to pre-fill the table. */ -static png_uint_32 crc_table[256]; - -/* Flag: has the table been computed? Initially false. */ -static int crc_table_computed = 0; - -/* make the table for a fast crc */ -static void -make_crc_table(void) -{ - png_uint_32 c; - int n, k; - - for (n = 0; n < 256; n++) - { - c = (png_uint_32)n; - for (k = 0; k < 8; k++) - c = c & 1 ? 0xedb88320L ^ (c >> 1) : c >> 1; - crc_table[n] = c; - } - crc_table_computed = 1; -} - -/* Update a running CRC with the bytes buf[0..len-1] - the CRC should be - initialized to all 1's, and the transmitted value is the 1's complement - of the final running CRC. */ -static png_uint_32 -update_crc(png_uint_32 crc, png_bytep buf, png_size_t len) -{ - png_uint_32 c; - png_bytep p; - png_uint_32 n; - - c = crc; - p = buf; - n = len; - - if (!crc_table_computed) - { - make_crc_table(); - } - - if (n > 0) do - { - c = crc_table[(png_byte)((c ^ (*p++)) & 0xff)] ^ (c >> 8); - } while (--n); - - return c; } -#endif /* PNG_USE_OWN_CRC */ /* Calculate the CRC over a section of data. We can only pass as - much data to this routine as the largest single buffer size. We - also check that this data will actually be used before going to the - trouble of calculating it. */ + * much data to this routine as the largest single buffer size. We + * also check that this data will actually be used before going to the + * trouble of calculating it. + */ void png_calculate_crc(png_structp png_ptr, png_bytep ptr, png_size_t length) { @@ -241,18 +184,15 @@ png_calculate_crc(png_structp png_ptr, png_bytep ptr, png_size_t length) } if (need_crc) -#ifdef PNG_USE_OWN_CRC - png_ptr->crc = update_crc(png_ptr->crc, ptr, length); -#else png_ptr->crc = crc32(png_ptr->crc, ptr, length); -#endif } /* Allocate the memory for an info_struct for the application. We don't - really need the png_ptr, but it could potentially be useful in the - future. This should be used in favour of malloc(sizeof(png_info)) - and png_info_init() so that applications that want to use a shared - libpng don't have to be recompiled if png_info changes size. */ + * really need the png_ptr, but it could potentially be useful in the + * future. This should be used in favour of malloc(sizeof(png_info)) + * and png_info_init() so that applications that want to use a shared + * libpng don't have to be recompiled if png_info changes size. + */ png_infop png_create_info_struct(png_structp png_ptr) { @@ -268,9 +208,10 @@ png_create_info_struct(png_structp png_ptr) } /* This function frees the memory associated with a single info struct. - Normally, one would use either png_destroy_read_struct() or - png_destroy_write_struct() to free an info struct, but this may be - useful for some applications. */ + * Normally, one would use either png_destroy_read_struct() or + * png_destroy_write_struct() to free an info struct, but this may be + * useful for some applications. + */ void png_destroy_info_struct(png_structp png_ptr, png_infopp info_ptr_ptr) { @@ -290,8 +231,9 @@ png_destroy_info_struct(png_structp png_ptr, png_infopp info_ptr_ptr) } /* Initialize the info structure. This is now an internal function (0.89) - and applications using it are urged to use png_create_info_struct() - instead. */ + * and applications using it are urged to use png_create_info_struct() + * instead. + */ void png_info_init(png_infop info_ptr) { @@ -337,8 +279,9 @@ png_info_destroy(png_structp png_ptr, png_infop info_ptr) } /* This function returns a pointer to the io_ptr associated with the user - functions. The application should free any memory associated with this - pointer before png_write_destroy() or png_read_destroy() are called. */ + * functions. The application should free any memory associated with this + * pointer before png_write_destroy() or png_read_destroy() are called. + */ png_voidp png_get_io_ptr(png_structp png_ptr) { @@ -347,8 +290,9 @@ png_get_io_ptr(png_structp png_ptr) #if !defined(PNG_NO_STDIO) /* Initialize the default input/output functions for the PNG file. If you - use your own read or write routines, you can call either png_set_read_fn() - or png_set_write_fn() instead of png_init_io(). */ + * use your own read or write routines, you can call either png_set_read_fn() + * or png_set_write_fn() instead of png_init_io(). + */ void png_init_io(png_structp png_ptr, FILE *fp) { @@ -1,67 +1,71 @@ /* png.h - header file for PNG reference library - - libpng 1.0 beta 6 - version 0.96 - For conditions of distribution and use, see copyright notice in png.h - Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. - Copyright (c) 1996, 1997 Andreas Dilger - May 12, 1997 - - BETA NOTICE: - This is a beta version. It reads and writes valid files on the - platforms I have, and has had a wide testing program. You may - have to modify the includes below to get it to work on your - system, and you may have to supply the correct compiler flags in - the makefile if you can't find a makefile suitable for your - operating system/compiler combination. Read libpng.txt for more - information, including how to contact the authors if you have any - problems, or if you want your compiler/platform to be supported in - the next official libpng release. - - See libpng.txt for more information. - - Contributing Authors: - John Bowler - Sam Bushell - Kevin Bracey - Andreas Dilger - Magnus Holmgren - Dave Martindale - Greg Roelofs - Guy Eric Schalnat - Paul Schmidt - Tom Tanner - Tim Wegner - - The contributing authors would like to thank all those who helped - with testing, bug fixes, and patience. This wouldn't have been - possible without all of you. - - Thanks to Frank J. T. Wojcik for helping with the documentation. - - The PNG Reference Library is supplied "AS IS". The Contributing Authors - and Group 42, Inc. disclaim all warranties, expressed or implied, - including, without limitation, the warranties of merchantability and of - fitness for any purpose. The Contributing Authors and Group 42, Inc. - assume no liability for direct, indirect, incidental, special, exemplary, - or consequential damages, which may result from the use of the PNG - Reference Library, even if advised of the possibility of such damage. - - Permission is hereby granted to use, copy, modify, and distribute this - source code, or portions hereof, for any purpose, without fee, subject - to the following restrictions: - 1. The origin of this source code must not be misrepresented. - 2. Altered versions must be plainly marked as such and must not be - misrepresented as being the original source. - 3. This Copyright notice may not be removed or altered from any source or - altered source distribution. - - The Contributing Authors and Group 42, Inc. specifically permit, without - fee, and encourage the use of this source code as a component to - supporting the PNG file format in commercial products. If you use this - source code in a product, acknowledgment is not required but would be - appreciated. -*/ + * + * libpng 1.00.97 beta 7 + * For conditions of distribution and use, see copyright notice in png.h + * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. + * Copyright (c) 1996, 1997 Andreas Dilger + * Dec 31, 1997 + * + * BETA NOTICE: + * This is a beta version. It reads and writes valid files on the + * platforms I have, and has had a wide testing program. You may + * have to modify the includes below to get it to work on your + * system, and you may have to supply the correct compiler flags in + * the makefile if you can't find a makefile suitable for your + * operating system/compiler combination. Read libpng.txt for more + * information, including how to contact the authors if you have any + * problems, or if you want your compiler/platform to be supported in + * the next official libpng release. + * + * See libpng.txt for more information. The PNG specification is available + * as RFC 2083 <ftp://ftp.uu.net/graphics/png/documents/> + * and as a W3C Recommendation <http://www.w3.org/pub/WWW/TR/REC.png.html> + * + * Contributing Authors: + * John Bowler + * Sam Bushell + * Kevin Bracey + * Andreas Dilger + * Magnus Holmgren + * Tom Lane + * Dave Martindale + * Glenn Randers-Pehrson + * Greg Roelofs + * Guy Eric Schalnat + * Paul Schmidt + * Tom Tanner + * Tim Wegner + * + * The contributing authors would like to thank all those who helped + * with testing, bug fixes, and patience. This wouldn't have been + * possible without all of you. + * + * Thanks to Frank J. T. Wojcik for helping with the documentation. + * + * The PNG Reference Library is supplied "AS IS". The Contributing Authors + * and Group 42, Inc. disclaim all warranties, expressed or implied, + * including, without limitation, the warranties of merchantability and of + * fitness for any purpose. The Contributing Authors and Group 42, Inc. + * assume no liability for direct, indirect, incidental, special, exemplary, + * or consequential damages, which may result from the use of the PNG + * Reference Library, even if advised of the possibility of such damage. + * + * Permission is hereby granted to use, copy, modify, and distribute this + * source code, or portions hereof, for any purpose, without fee, subject + * to the following restrictions: + * 1. The origin of this source code must not be misrepresented. + * 2. Altered versions must be plainly marked as such and must not be + * misrepresented as being the original source. + * 3. This Copyright notice may not be removed or altered from any source or + * altered source distribution. + * + * The Contributing Authors and Group 42, Inc. specifically permit, without + * fee, and encourage the use of this source code as a component to + * supporting the PNG file format in commercial products. If you use this + * source code in a product, acknowledgment is not required but would be + * appreciated. + */ #ifndef _PNG_H #define _PNG_H @@ -89,12 +93,12 @@ extern "C" { */ /* Version information for png.h - this should match the version in png.c */ -#define PNG_LIBPNG_VER_STRING "0.96" +#define PNG_LIBPNG_VER_STRING "1.00.97" /* careful here. At one time, I wanted to use 082, but that would be octal. * Version 1.0 will be 100 here, etc. */ -#define PNG_LIBPNG_VER 96 +#define PNG_LIBPNG_VER 97 /* variables declared in png.c - only it needs to define PNG_NO_EXTERN */ #ifndef PNG_NO_EXTERN @@ -172,10 +176,11 @@ typedef png_text FAR * FAR * png_textpp; #define PNG_TEXT_COMPRESSION_LAST 1 /* Not a valid value */ /* png_time is a way to hold the time in an machine independent way. - Two conversions are provided, both from time_t and struct tm. There - is no portable way to convert to either of these structures, as far - as I know. If you know of a portable way, send it to me. As a side - note - PNG is Year 2000 compliant! */ + * Two conversions are provided, both from time_t and struct tm. There + * is no portable way to convert to either of these structures, as far + * as I know. If you know of a portable way, send it to me. As a side + * note - PNG is Year 2000 compliant! + */ typedef struct png_time_struct { png_uint_16 year; /* full year, as in, 1995 */ @@ -244,6 +249,13 @@ typedef struct png_info_struct */ float gamma; /* gamma value of image, if (valid & PNG_INFO_gAMA) */ #endif /* PNG_READ_gAMA_SUPPORTED || PNG_WRITE_gAMA_SUPPORTED */ + +#if defined(PNG_READ_sRGB_SUPPORTED) || defined(PNG_WRITE_sRGB_SUPPORTED) + /* GR-P, 0.96a */ + /* Data valid if (valid & PNG_INFO_sRGB) non-zero. */ + png_byte srgb_intent; /* sRGB rendering intent [0, 1, 2, or 3] */ +#endif /* PNG_READ_sRGB_SUPPORTED || PNG_WRITE_sRGB_SUPPORTED */ + #if defined(PNG_READ_tEXt_SUPPORTED) || defined(PNG_WRITE_tEXt_SUPPORTED) || \ defined(PNG_READ_zTXt_SUPPORTED) || defined(PNG_WRITE_zTXt_SUPPORTED) /* The tEXt and zTXt chunks contain human-readable textual data in @@ -422,6 +434,7 @@ typedef png_info FAR * FAR * png_infopp; #define PNG_INFO_oFFs 0x0100 #define PNG_INFO_tIME 0x0200 #define PNG_INFO_pCAL 0x0400 +#define PNG_INFO_sRGB 0x0800 /* GR-P, 0.96a */ /* This is used for the transformation routines, as some of them * change these values for the row. It also should enable using @@ -524,7 +537,6 @@ struct png_struct_def png_byte usr_channels; /* channels at start of write */ png_byte sig_bytes; /* magic bytes read/written from start of file */ - #if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED) png_byte filler; /* filler byte for 24->32-bit pixel expansion */ #endif /* PNG_READ_FILLER_SUPPORTED */ @@ -609,6 +621,9 @@ struct png_struct_def png_uint_16p filter_costs; /* relative filter calculation cost */ png_uint_16p inv_filter_costs; /* 1/relative filter calculation cost */ #endif /* PNG_WRITE_WEIGHTED_FILTER_SUPPORTED */ +#if defined(PNG_TIME_RFC1152_SUPPORTED) + png_charp time_buffer; /* String to hold RFC 1152 time text */ +#endif /* PNG_TIME_RFC1152_SUPPORTED */ }; typedef png_struct FAR * FAR * png_structpp; @@ -640,8 +655,8 @@ extern PNG_EXPORT(int,png_check_sig) PNGARG((png_bytep sig, int num)); /* Allocate and initialize png_ptr struct for reading, and any other memory. */ extern PNG_EXPORT(png_structp,png_create_read_struct) - PNGARG((png_charp user_png_ver, voidp error_ptr, png_error_ptr error_fn, - png_error_ptr warn_fn)); + PNGARG((png_const_charp user_png_ver, voidp error_ptr, + png_error_ptr error_fn, png_error_ptr warn_fn)); /* Allocate and initialize png_ptr struct for reading, and any other memory */ extern PNG_EXPORT(png_structp,png_create_write_struct) @@ -663,6 +678,11 @@ extern PNG_EXPORT(void,png_write_info) PNGARG((png_structp png_ptr, extern PNG_EXPORT(void,png_read_info) PNGARG((png_structp png_ptr, png_infop info_ptr)); +#if defined(PNG_TIME_RFC1152_SUPPORTED) +extern PNG_EXPORT(png_charp,png_convert_to_rfc1152) + PNGARG((png_structp png_ptr, png_timep ptime)); +#endif /* PNG_TIME_RFC1152_SUPPORTED */ + #if defined(PNG_WRITE_tIME_SUPPORTED) /* convert from a struct tm to png_time */ extern PNG_EXPORT(void,png_convert_from_struct_tm) PNGARG((png_timep ptime, @@ -840,6 +860,9 @@ extern void png_read_destroy PNGARG((png_structp png_ptr, png_infop info_ptr, extern PNG_EXPORT(void,png_destroy_write_struct) PNGARG((png_structpp png_ptr_ptr, png_infopp info_ptr_ptr)); +/* free any memory used in info_ptr struct (old method - NOT DLL EXPORTED) */ +extern void png_write_destroy_info PNGARG((png_infop info_ptr)); + /* free any memory used in png_ptr struct (old method - NOT DLL EXPORTED) */ extern void png_write_destroy PNGARG((png_structp png_ptr)); @@ -868,10 +891,12 @@ extern PNG_EXPORT(void,png_set_crc_action) PNGARG((png_structp png_ptr, * mainly useful for testing, as the defaults should work with most users. * Those users who are tight on memory or want faster performance at the * expense of compression can modify them. See the compression library - * header file (zlib.h) for an explination of the compression functions. */ + * header file (zlib.h) for an explination of the compression functions. + */ /* set the filtering method(s) used by libpng. Currently, the only valid - * value for "method" is 0 */ + * value for "method" is 0. + */ extern PNG_EXPORT(void,png_set_filter) PNGARG((png_structp png_ptr, int method, int filters)); @@ -1030,7 +1055,7 @@ extern PNG_EXPORT(void,png_progressive_combine_row) PNGARG((png_structp png_ptr, extern PNG_EXPORT(png_voidp,png_malloc) PNGARG((png_structp png_ptr, png_uint_32 size)); -/* free's a pointer allocated by png_malloc() */ +/* frees a pointer allocated by png_malloc() */ extern PNG_EXPORT(void,png_free) PNGARG((png_structp png_ptr, png_voidp ptr)); #if defined(USE_FAR_KEYWORD) /* memory model conversion function */ @@ -1175,6 +1200,18 @@ extern PNG_EXPORT(void,png_set_sBIT) PNGARG((png_structp png_ptr, png_infop info_ptr, png_color_8p sig_bit)); #endif /* PNG_READ_sBIT_SUPPORTED || PNG_WRITE_sBIT_SUPPORTED */ +#if defined(PNG_READ_sRGB_SUPPORTED) +extern PNG_EXPORT(png_uint_32,png_get_sRGB) PNGARG((png_structp png_ptr, + png_infop info_ptr, png_byte *srgb_intent)); +#endif /* PNG_READ_sRGB_SUPPORTED */ + +#if defined(PNG_READ_sRGB_SUPPORTED) || defined(PNG_WRITE_sRGB_SUPPORTED) +extern PNG_EXPORT(void,png_set_sRGB) PNGARG((png_structp png_ptr, + png_infop info_ptr, png_byte srgb_intent)); +extern PNG_EXPORT(void,png_set_sRGB_gAMA_and_cHRM) PNGARG((png_structp png_ptr, + png_infop info_ptr, png_byte srgb_intent)); +#endif /* PNG_READ_sRGB_SUPPORTED || PNG_WRITE_sRGB_SUPPORTED */ + #if defined(PNG_READ_tEXt_SUPPORTED) || defined(PNG_READ_zTXt_SUPPORTED) /* png_get_text also returns the number of text chunks in text_ptr */ extern PNG_EXPORT(png_uint_32,png_get_text) PNGARG((png_structp png_ptr, @@ -1244,13 +1281,17 @@ extern PNG_EXPORT(void,png_set_tRNS) PNGARG((png_structp png_ptr, #if defined(PNG_INTERNAL) /* Various modes of operation. Note that after an init, mode is set to - zero automatically when the structure is created. */ + * zero automatically when the structure is created. + */ #define PNG_BEFORE_IHDR 0x00 #define PNG_HAVE_IHDR 0x01 #define PNG_HAVE_PLTE 0x02 #define PNG_HAVE_IDAT 0x04 #define PNG_AFTER_IDAT 0x08 #define PNG_HAVE_IEND 0x10 +#define PNG_HAVE_gAMA 0x20 +#define PNG_HAVE_cHRM 0x40 +#define PNG_HAVE_sRGB 0x80 /* push model modes */ #define PNG_READ_SIG_MODE 0 @@ -1331,10 +1372,11 @@ extern PNG_EXPORT(void,png_set_tRNS) PNGARG((png_structp png_ptr, /* place to hold the signiture string for a PNG file. */ extern png_byte FARDATA png_sig[]; -/* constant strings for known chunk types. If you need to add a chunk, - add a string holding the name here. See png.c for more details. We - can't selectively include these, since we still check for chunk in the - wrong locations with these labels. */ +/* Constant strings for known chunk types. If you need to add a chunk, + * add a string holding the name here. See png.c for more details. We + * can't selectively include these, since we still check for chunk in the + * wrong locations with these labels. + */ extern png_byte FARDATA png_IHDR[]; extern png_byte FARDATA png_IDAT[]; extern png_byte FARDATA png_IEND[]; @@ -1347,6 +1389,7 @@ extern png_byte FARDATA png_oFFs[]; extern png_byte FARDATA png_pCAL[]; extern png_byte FARDATA png_pHYs[]; extern png_byte FARDATA png_sBIT[]; +extern png_byte FARDATA png_sRGB[]; extern png_byte FARDATA png_tEXt[]; extern png_byte FARDATA png_tIME[]; extern png_byte FARDATA png_tRNS[]; @@ -1376,12 +1419,14 @@ PNG_EXTERN png_uint_32 png_get_uint_32 PNGARG((png_bytep buf)); PNG_EXTERN png_uint_16 png_get_uint_16 PNGARG((png_bytep buf)); #endif /* PNG_BIG_ENDIAN_GET_SUPPORTED */ -/* Initialize png_ptr struct for reading, and allocate any other memory - * (old interface - NOT DLL EXPORTED) */ +/* Initialize png_ptr struct for reading, and allocate any other memory. + * (old interface - NOT DLL EXPORTED). + */ extern void png_read_init PNGARG((png_structp png_ptr)); -/* Initialize png_ptr struct for writing, and allocate any other memory - * (old interface - NOT DLL EXPORTED) */ +/* Initialize png_ptr struct for writing, and allocate any other memory. + * (old interface - NOT DLL EXPORTED). + */ extern void png_write_init PNGARG((png_structp png_ptr)); /* allocate memory for an internal libpng struct */ @@ -1433,7 +1478,7 @@ PNG_EXTERN void png_flush PNGARG((png_structp png_ptr)); #endif /* Place a 32-bit number into a buffer in PNG byte order (big-endian). - * The only currently known PNG chunk that uses unsigned numbers is + * The only currently known PNG chunk that uses signed numbers is * the ancillary extension chunk, pCAL. */ PNG_EXTERN void png_save_uint_32 PNGARG((png_bytep buf, png_uint_32 i)); @@ -1442,8 +1487,11 @@ PNG_EXTERN void png_save_uint_32 PNGARG((png_bytep buf, png_uint_32 i)); PNG_EXTERN void png_save_int_32 PNGARG((png_bytep buf, png_int_32 i)); #endif -/* place a 16 bit number into a buffer in PNG byte order */ -PNG_EXTERN void png_save_uint_16 PNGARG((png_bytep buf, png_uint_16 i)); +/* Place a 16 bit number into a buffer in PNG byte order. + * The parameter is declared unsigned int, not png_uint_16, + * just to avoid potential problems on pre-ANSI C compilers. + */ +PNG_EXTERN void png_save_uint_16 PNGARG((png_bytep buf, unsigned int i)); /* Write a PNG chunk - size, type, (optional) data, CRC. */ PNG_EXTERN void png_write_chunk PNGARG((png_structp png_ptr, @@ -1466,7 +1514,8 @@ PNG_EXTERN void png_write_sig PNGARG((png_structp png_ptr)); /* write various chunks */ /* Write the IHDR chunk, and update the png_struct with the necessary - information. */ + * information. + */ PNG_EXTERN void png_write_IHDR PNGARG((png_structp png_ptr, png_uint_32 width, png_uint_32 height, int bit_depth, int color_type, int compression_type, int filter_type, @@ -1496,6 +1545,11 @@ PNG_EXTERN void png_write_cHRM PNGARG((png_structp png_ptr, double blue_x, double blue_y)); #endif +#if defined(PNG_WRITE_sRGB_SUPPORTED) +PNG_EXTERN void png_write_sRGB PNGARG((png_structp png_ptr, + png_byte srgb_intent)); +#endif + #if defined(PNG_WRITE_tRNS_SUPPORTED) PNG_EXTERN void png_write_tRNS PNGARG((png_structp png_ptr, png_bytep trans, png_color_16p values, int number, int color_type)); @@ -1513,7 +1567,7 @@ PNG_EXTERN void png_write_hIST PNGARG((png_structp png_ptr, png_uint_16p hist, #if defined(PNG_WRITE_tEXt_SUPPORTED) || defined(PNG_WRITE_zTXt_SUPPORTED) PNG_EXTERN png_size_t png_check_keyword PNGARG((png_structp png_ptr, - png_charp key, png_bytepp new_key)); + png_charp key, png_charpp new_key)); #endif #if defined(PNG_WRITE_tEXt_SUPPORTED) @@ -1698,7 +1752,8 @@ PNG_EXTERN void png_do_expand PNGARG((png_row_infop row_info, #endif /* The following decodes the appropriate chunks, and does error correction, - * then calls the appropriate callback for the chunk if it is valid */ + * then calls the appropriate callback for the chunk if it is valid. + */ /* decode the IHDR chunk */ PNG_EXTERN void png_handle_IHDR PNGARG((png_structp png_ptr, png_infop info_ptr, @@ -1723,6 +1778,11 @@ PNG_EXTERN void png_handle_cHRM PNGARG((png_structp png_ptr, png_infop info_ptr, png_uint_32 length)); #endif +#if defined(PNG_READ_sRGB_SUPPORTED) +PNG_EXTERN void png_handle_sRGB PNGARG((png_structp png_ptr, png_infop info_ptr, + png_uint_32 length)); +#endif + #if defined(PNG_READ_tRNS_SUPPORTED) PNG_EXTERN void png_handle_tRNS PNGARG((png_structp png_ptr, png_infop info_ptr, png_uint_32 length)); @@ -1,66 +1,69 @@ /* pngconf.c - machine configurable file for libpng - - libpng 1.0 beta 6 - version 0.96 - For conditions of distribution and use, see copyright notice in png.h - Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. - Copyright (c) 1996, 1997 Andreas Dilger - May 12, 1997 - */ + * + * libpng 1.00.97 + * For conditions of distribution and use, see copyright notice in png.h + * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. + * Copyright (c) 1996, 1997 Andreas Dilger + * May 28, 1997 + */ /* Any machine specific code is near the front of this file, so if you - are configuring libpng for a machine, you may want to read the section - starting here down to where it starts to typedef png_color, png_text, - and png_info */ + * are configuring libpng for a machine, you may want to read the section + * starting here down to where it starts to typedef png_color, png_text, + * and png_info. + */ #ifndef PNGCONF_H #define PNGCONF_H /* This is the size of the compression buffer, and thus the size of - an IDAT chunk. Make this whatever size you feel is best for your - machine. One of these will be allocated per png_struct. When this - is full, it writes the data to the disk, and does some other - calculations. Making this an extreamly small size will slow - the library down, but you may want to experiment to determine - where it becomes significant, if you are concerned with memory - usage. Note that zlib allocates at least 32Kb also. For readers, - this describes the size of the buffer available to read the data in. - Unless this gets smaller then the size of a row (compressed), - it should not make much difference how big this is. */ + * an IDAT chunk. Make this whatever size you feel is best for your + * machine. One of these will be allocated per png_struct. When this + * is full, it writes the data to the disk, and does some other + * calculations. Making this an extreamly small size will slow + * the library down, but you may want to experiment to determine + * where it becomes significant, if you are concerned with memory + * usage. Note that zlib allocates at least 32Kb also. For readers, + * this describes the size of the buffer available to read the data in. + * Unless this gets smaller then the size of a row (compressed), + * it should not make much difference how big this is. + */ #define PNG_ZBUF_SIZE 8192 /* If you are running on a machine where you cannot allocate more - than 64K of memory at once, uncomment this. While libpng will not - normally need that much memory in a chunk (unless you load up a very - large file), zlib needs to know how big of a chunk it can use, and - libpng thus makes sure to check any memory allocation to verify it - will fit into memory. + * than 64K of memory at once, uncomment this. While libpng will not + * normally need that much memory in a chunk (unless you load up a very + * large file), zlib needs to know how big of a chunk it can use, and + * libpng thus makes sure to check any memory allocation to verify it + * will fit into memory. #define PNG_MAX_MALLOC_64K -*/ + */ #if defined(MAXSEG_64K) && !defined(PNG_MAX_MALLOC_64K) #define PNG_MAX_MALLOC_64K #endif /* This protects us against compilers which run on a windowing system - and thus don't have or would rather us not use the stdio types: - stdin, stdout, and stderr. The only one currently used is stderr - in png_error() and png_warning(). #defining PNG_NO_STDIO will - prevent these from being compiled and used. */ + * and thus don't have or would rather us not use the stdio types: + * stdin, stdout, and stderr. The only one currently used is stderr + * in png_error() and png_warning(). #defining PNG_NO_STDIO will + * prevent these from being compiled and used. + * #define PNG_NO_STDIO + */ -/* #define PNG_NO_STDIO */ +/* We still need stdio.h for FILE even when PNG_NO_STDIO is defined. + */ -/* for FILE. If you are not using standard io, you don't need this */ -#ifndef PNG_NO_STDIO #include <stdio.h> -#endif /* This macro protects us against machines that don't have function - prototypes (ie K&R style headers). If your compiler does not handle - function prototypes, define this macro and use the included ansi2knr. - I've always been able to use _NO_PROTO as the indicator, but you may - need to drag the empty declaration out in front of here, or change the - ifdef to suit your own needs. */ + * prototypes (ie K&R style headers). If your compiler does not handle + * function prototypes, define this macro and use the included ansi2knr. + * I've always been able to use _NO_PROTO as the indicator, but you may + * need to drag the empty declaration out in front of here, or change the + * ifdef to suit your own needs. + */ #ifndef PNGARG #ifdef OF /* zlib prototype munger */ @@ -77,8 +80,12 @@ #endif /* PNGARG */ -/* Try to determine if we are compiling on a Mac */ -#if defined(__MWERKS__) ||defined(applec) ||defined(THINK_C) ||defined(__SC__) +/* Try to determine if we are compiling on a Mac. Note that testing for + * just __MWERKS__ is not good enough, because the Codewarrior is now used + * on non-Mac platforms. + */ +#if (defined(__MWERKS__) && defined(macintosh)) || defined(applec) || \ + defined(THINK_C) || defined(__SC__) #define MACOS #endif @@ -88,27 +95,28 @@ #endif /* This is an attempt to force a single setjmp behaviour on Linux. If - the X config stuff didn't define _BSD_SOURCE we wouldn't need this. */ -#ifdef linux + * the X config stuff didn't define _BSD_SOURCE we wouldn't need this. + */ +#ifdef __linux__ #ifdef _BSD_SOURCE #define _PNG_SAVE_BSD_SOURCE #undef _BSD_SOURCE #endif #ifdef _SETJMP_H -#error __png_h_already_includes_setjmp_h__ -#error __dont_include_it_again__ +__png.h__ already includes setjmp.h +__dont__ include it again #endif -#endif /* linux */ +#endif /* __linux__ */ /* include setjmp.h for error handling */ #include <setjmp.h> -#ifdef linux +#ifdef __linux__ #ifdef _PNG_SAVE_BSD_SOURCE #define _BSD_SOURCE #undef _PNG_SAVE_BSD_SOURCE #endif -#endif /* linux */ +#endif /* __linux__ */ #ifdef BSD #include <strings.h> @@ -119,9 +127,6 @@ /* Other defines for things like memory and the like can go here. */ #ifdef PNG_INTERNAL #include <stdlib.h> -/* Where do we need this??? -#include <ctype.h> -*/ /* The functions exported by PNG_EXTERN are PNG_INTERNAL functions, which * aren't usually used outside the library (as far as I know), so it is @@ -133,12 +138,14 @@ #define PNG_EXTERN /* Other defines specific to compilers can go here. Try to keep - them inside an appropriate ifdef/endif pair for portability */ + * them inside an appropriate ifdef/endif pair for portability. + */ #if defined(MACOS) /* We need to check that <math.h> hasn't already been included earlier - as it seems it doesn't agree with <fp.h>, yet we should really use - <fp.h> if possible. */ + * as it seems it doesn't agree with <fp.h>, yet we should really use + * <fp.h> if possible. + */ #if !defined(__MATH_H__) && !defined(__MATH_H) && !defined(__cmath__) #include <fp.h> #endif @@ -147,8 +154,9 @@ #endif /* For some reason, Borland C++ defines memcmp, etc. in mem.h, not - stdlib.h like it should (I think). Or perhaps this is a C++ - "feature"? */ + * stdlib.h like it should (I think). Or perhaps this is a C++ + * "feature"? + */ #ifdef __TURBOC__ #include <mem.h> #include "alloc.h" @@ -159,34 +167,36 @@ #endif /* This controls how fine the dithering gets. As this allocates - a largish chunk of memory (32K), those who are not as concerned - with dithering quality can decrease some or all of these. */ + * a largish chunk of memory (32K), those who are not as concerned + * with dithering quality can decrease some or all of these. + */ #define PNG_DITHER_RED_BITS 5 #define PNG_DITHER_GREEN_BITS 5 #define PNG_DITHER_BLUE_BITS 5 /* This controls how fine the gamma correction becomes when you - are only interested in 8 bits anyway. Increasing this value - results in more memory being used, and more pow() functions - being called to fill in the gamma tables. Don't set this - value less then 8, and even that may not work (I haven't tested - it). */ + * are only interested in 8 bits anyway. Increasing this value + * results in more memory being used, and more pow() functions + * being called to fill in the gamma tables. Don't set this value + * less then 8, and even that may not work (I haven't tested it). + */ #define PNG_MAX_GAMMA_8 11 /* This controls how much a difference in gamma we can tolerate before - we actually start doing gamma conversion. */ + * we actually start doing gamma conversion. + */ #define PNG_GAMMA_THRESHOLD 0.05 #endif /* PNG_INTERNAL */ /* The following uses const char * instead of char * for error - and warning message functions, so some compilers won't complain. - If you want to use const, define PNG_USE_CONST here. It is not - normally defined to make configuration easier, as it is not a - critical part of the code. - */ -#undef PNG_USE_CONST + * and warning message functions, so some compilers won't complain. + * If you want to use const, define PNG_USE_CONST here. It is not + * normally defined to make configuration easier, as it is not a + * critical part of the code. + */ +#define PNG_USE_CONST #ifdef PNG_USE_CONST # define PNG_CONST const @@ -195,19 +205,34 @@ #endif /* The following defines give you the ability to remove code from the - library that you will not be using. I wish I could figure out how to - automate this, but I can't do that without making it seriously hard - on the users. So if you are not using an ability, change the #define - to and #undef, and that part of the library will not be compiled. If - your linker can't find a function, you may want to make sure the - ability is defined here. Some of these depend upon some others being - defined. I haven't figured out all the interactions here, so you may - have to experiment awhile to get everything to compile. If you are - creating or using a shared library, you probably shouldn't touch this, - as it will affect the size of the structures, and this will cause bad - things to happen if the library and/or application ever change. */ + * library that you will not be using. I wish I could figure out how to + * automate this, but I can't do that without making it seriously hard + * on the users. So if you are not using an ability, change the #define + * to and #undef, and that part of the library will not be compiled. If + * your linker can't find a function, you may want to make sure the + * ability is defined here. Some of these depend upon some others being + * defined. I haven't figured out all the interactions here, so you may + * have to experiment awhile to get everything to compile. If you are + * creating or using a shared library, you probably shouldn't touch this, + * as it will affect the size of the structures, and this will cause bad + * things to happen if the library and/or application ever change. + */ /* Any transformations you will not be using can be undef'ed here */ + +/* GR-P, 0.96a: Set "*FULLY_SUPPORTED as default but allow user + to turn it off with "*NOT_FULLY_SUPPORTED" on the compile line, + then pick and choose which ones to define without having to edit + this file */ + +#ifndef PNG_READ_NOT_FULLY_SUPPORTED +#define PNG_READ_FULLY_SUPPORTED +#endif +#ifndef PNG_WRITE_NOT_FULLY_SUPPORTED +#define PNG_WRITE_FULLY_SUPPORTED +#endif + +#ifdef PNG_READ_FULLY_SUPPORTED #define PNG_PROGRESSIVE_READ_SUPPORTED #define PNG_READ_OPT_PLTE_SUPPORTED #define PNG_READ_INTERLACING_SUPPORTED @@ -226,7 +251,9 @@ #define PNG_READ_GRAY_TO_RGB_SUPPORTED #define PNG_READ_SWAP_ALPHA_SUPPORTED #define PNG_READ_STRIP_ALPHA_SUPPORTED +#endif /* PNG_READ_FULLY_SUPPORTED */ +#ifdef PNG_WRITE_FULLY_SUPPORTED #define PNG_WRITE_INTERLACING_SUPPORTED #define PNG_WRITE_SHIFT_SUPPORTED #define PNG_WRITE_PACK_SUPPORTED @@ -238,6 +265,9 @@ #define PNG_WRITE_FLUSH_SUPPORTED #define PNG_WRITE_SWAP_ALPHA_SUPPORTED #define PNG_WRITE_WEIGHTED_FILTER_SUPPORTED +#endif /*PNG_WRITE_FULLY_SUPPORTED */ + +#define PNG_TIME_RFC1152_SUPPORTED /* These are currently experimental features */ #undef PNG_READ_16_TO_8_ACCURATE_SHIFT_SUPPORTED /* very little testing */ @@ -247,7 +277,6 @@ #undef PNG_READ_BIG_ENDIAN_SUPPORTED /* some testing */ /* These functions are turned off by default, as they will be phased out. */ -#undef PNG_USE_OWN_CRC #undef PNG_USELESS_TESTS_SUPPORTED #undef PNG_CORRECT_PALETTE_SUPPORTED @@ -258,6 +287,7 @@ * and RGBA images. */ +#ifdef PNG_READ_FULLY_SUPPORTED #define PNG_READ_bKGD_SUPPORTED #define PNG_READ_cHRM_SUPPORTED #define PNG_READ_gAMA_SUPPORTED @@ -266,11 +296,14 @@ #define PNG_READ_pCAL_SUPPORTED #define PNG_READ_pHYs_SUPPORTED #define PNG_READ_sBIT_SUPPORTED +#define PNG_READ_sRGB_SUPPORTED #define PNG_READ_tEXt_SUPPORTED #define PNG_READ_tIME_SUPPORTED #define PNG_READ_tRNS_SUPPORTED #define PNG_READ_zTXt_SUPPORTED +#endif /* PNG_READ_FULLY_SUPPORTED */ +#ifdef PNG_WRITE_FULLY_SUPPORTED #define PNG_WRITE_bKGD_SUPPORTED #define PNG_WRITE_cHRM_SUPPORTED #define PNG_WRITE_gAMA_SUPPORTED @@ -279,10 +312,12 @@ #define PNG_WRITE_pCAL_SUPPORTED #define PNG_WRITE_pHYs_SUPPORTED #define PNG_WRITE_sBIT_SUPPORTED +#define PNG_WRITE_sRGB_SUPPORTED #define PNG_WRITE_tEXt_SUPPORTED #define PNG_WRITE_tIME_SUPPORTED #define PNG_WRITE_tRNS_SUPPORTED #define PNG_WRITE_zTXt_SUPPORTED +#endif /* PNG_WRITE_FULLY_SUPPORTED */ /* need the time information for reading tIME chunks */ #if defined(PNG_READ_tIME_SUPPORTED) || defined(PNG_WRITE_tIME_SUPPORTED) @@ -336,18 +371,19 @@ typedef size_t png_size_t; #endif /* LDATA != 1 */ /* Possibly useful for moving data out of default segment. - Uncomment it if you want. Could also define FARDATA as - const if your compiler supports it. (SJT) + * Uncomment it if you want. Could also define FARDATA as + * const if your compiler supports it. (SJT) # define FARDATA FAR -*/ + */ #endif /* __WIN32__, __FLAT__ */ #endif /* __BORLANDC__ */ /* Suggest testing for specific compiler first before testing for - FAR. The Watcom compiler defines both __MEDIUM__ and M_I86MM, - making reliance oncertain keywords suspect. (SJT) */ + * FAR. The Watcom compiler defines both __MEDIUM__ and M_I86MM, + * making reliance oncertain keywords suspect. (SJT) + */ /* MSC Medium model */ #if defined(FAR) @@ -400,18 +436,29 @@ typedef charf * png_zcharp; typedef charf * FAR * png_zcharpp; typedef z_stream FAR * png_zstreamp; -/* allow for compilation as dll under windows */ +/* allow for compilation as dll under MS Windows */ #ifdef __WIN32DLL__ #define PNG_EXPORT(type,symbol) __declspec(dllexport) type symbol #endif +/* allow for compilation as dll with BORLAND C++ 5.0 */ +#if defined(__BORLANDC__) && defined(_Windows) && defined(__DLL__) +# define PNG_EXPORT(t,s) t _export s +#endif + +/* allow for compilation as shared lib under BeOS */ +#ifdef __BEOSDLL__ +#define PNG_EXPORT(type,symbol) __declspec(export) type symbol +#endif + #ifndef PNG_EXPORT #define PNG_EXPORT(t,s) t s #endif /* User may want to use these so not in PNG_INTERNAL. Any library functions - that are passed far data must be model independent. */ + * that are passed far data must be model independent. + */ #if defined(USE_FAR_KEYWORD) /* memory model independent fns */ /* use this to make far-to-near assignments */ diff --git a/pngerror.c b/pngerror.c index 70a3ee057..a800884df 100644 --- a/pngerror.c +++ b/pngerror.c @@ -1,16 +1,17 @@ /* pngerror.c - stub functions for i/o and memory allocation - - libpng 1.0 beta 6 - version 0.96 - For conditions of distribution and use, see copyright notice in png.h - Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. - Copyright (c) 1996, 1997 Andreas Dilger - May 12, 1997 - - This file provides a location for all error handling. Users which - need special error handling are expected to write replacement functions - and use png_set_error_fn() to use those functions. See the instructions - at each function. */ + * + * libpng 1.00.97 + * For conditions of distribution and use, see copyright notice in png.h + * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. + * Copyright (c) 1996, 1997 Andreas Dilger + * May 28, 1997 + * + * This file provides a location for all error handling. Users which + * need special error handling are expected to write replacement functions + * and use png_set_error_fn() to use those functions. See the instructions + * at each function. + */ #define PNG_INTERNAL #include "png.h" @@ -21,9 +22,10 @@ static void png_default_warning PNGARG((png_structp png_ptr, png_const_charp message)); /* This function is called whenever there is a fatal error. This function - should not be changed. If there is a need to handle errors differently, - you should supply a replacement error function and use png_set_error_fn() - to replace the error function at run-time. */ + * should not be changed. If there is a need to handle errors differently, + * you should supply a replacement error function and use png_set_error_fn() + * to replace the error function at run-time. + */ void png_error(png_structp png_ptr, png_const_charp message) { @@ -36,9 +38,10 @@ png_error(png_structp png_ptr, png_const_charp message) } /* This function is called whenever there is a non-fatal error. This function - should not be changed. If there is a need to handle warnings differently, - you should supply a replacement warning function and use - png_set_error_fn() to replace the warning function at run-time. */ + * should not be changed. If there is a need to handle warnings differently, + * you should supply a replacement warning function and use + * png_set_error_fn() to replace the warning function at run-time. + */ void png_warning(png_structp png_ptr, png_const_charp message) { @@ -49,9 +52,10 @@ png_warning(png_structp png_ptr, png_const_charp message) } /* This is the default error handling function. Note that replacements for - this function MUST NOT RETURN, or the program will likely crash. This - function is used by default, or if the program supplies NULL for the - error function pointer in png_set_error_fn(). */ + * this function MUST NOT RETURN, or the program will likely crash. This + * function is used by default, or if the program supplies NULL for the + * error function pointer in png_set_error_fn(). + */ static void png_default_error(png_structp png_ptr, png_const_charp message) { @@ -71,9 +75,10 @@ png_default_error(png_structp png_ptr, png_const_charp message) } /* This function is called when there is a warning, but the library thinks - it can continue anyway. Replacement functions don't have to do anything - here if you don't want to. In the default configuration, png_ptr is - not used, but it is passed in case it may be useful. */ + * it can continue anyway. Replacement functions don't have to do anything + * here if you don't want to. In the default configuration, png_ptr is + * not used, but it is passed in case it may be useful. + */ static void png_default_warning(png_structp png_ptr, png_const_charp message) { @@ -86,9 +91,10 @@ png_default_warning(png_structp png_ptr, png_const_charp message) } /* This function is called when the application wants to use another method - of handling errors and warnings. Note that the error function MUST NOT - return to the calling routine or serious problems will occur. The return - method used in the default routine calls longjmp(png_ptr->jmpbuf, 1) */ + * of handling errors and warnings. Note that the error function MUST NOT + * return to the calling routine or serious problems will occur. The return + * method used in the default routine calls longjmp(png_ptr->jmpbuf, 1) + */ void png_set_error_fn(png_structp png_ptr, png_voidp error_ptr, png_error_ptr error_fn, png_error_ptr warning_fn) @@ -100,8 +106,9 @@ png_set_error_fn(png_structp png_ptr, png_voidp error_ptr, /* This function returns a pointer to the error_ptr associated with the user - functions. The application should free any memory associated with this - pointer before png_write_destroy and png_read_destroy are called. */ + * functions. The application should free any memory associated with this + * pointer before png_write_destroy and png_read_destroy are called. + */ png_voidp png_get_error_ptr(png_structp png_ptr) { @@ -1,12 +1,12 @@ /* pngget.c - retrieval of values from info struct - - libpng 1.0 beta 6 - version 0.96 - For conditions of distribution and use, see copyright notice in png.h - Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. - Copyright (c) 1996, 1997 Andreas Dilger - May 12, 1997 - */ + * + * libpng 1.00.97 + * For conditions of distribution and use, see copyright notice in png.h + * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. + * Copyright (c) 1996, 1997 Andreas Dilger + * May 28, 1997 + */ #define PNG_INTERNAL #include "png.h" @@ -109,6 +109,21 @@ png_get_gAMA(png_structp png_ptr, png_infop info_ptr, double *file_gamma) } #endif +#if defined(PNG_READ_sRGB_SUPPORTED) +png_uint_32 +png_get_sRGB(png_structp png_ptr, png_infop info_ptr, png_byte *file_srgb_intent) +{ + if (info_ptr != NULL && info_ptr->valid & PNG_INFO_sRGB && + *file_srgb_intent != NULL) + { + png_debug1(1, "in %s retrieval function\n", "sRGB"); + *file_srgb_intent = (png_byte)info_ptr->srgb_intent; + return (PNG_INFO_sRGB); + } + return (0); +} +#endif + #if defined(PNG_READ_hIST_SUPPORTED) png_uint_32 png_get_hIST(png_structp png_ptr, png_infop info_ptr, png_uint_16p *hist) @@ -196,14 +211,23 @@ png_uint_32 png_get_pHYs(png_structp png_ptr, png_infop info_ptr, png_uint_32 *res_x, png_uint_32 *res_y, int *unit_type) { - if (info_ptr != NULL && info_ptr->valid & PNG_INFO_pHYs && - res_x != NULL && res_y != NULL && unit_type != NULL) + png_uint_32 retval = 0; + + if (info_ptr != NULL && info_ptr->valid & PNG_INFO_pHYs) { png_debug1(1, "in %s retrieval function\n", "pHYs"); - *res_x = info_ptr->x_pixels_per_unit; - *res_y = info_ptr->y_pixels_per_unit; - *unit_type = (int)info_ptr->phys_unit_type; - return (PNG_INFO_pHYs); + if (res_x != NULL && res_y != NULL) + { + *res_x = info_ptr->x_pixels_per_unit; + *res_y = info_ptr->y_pixels_per_unit; + retval |= PNG_INFO_pHYs; + } + if (unit_type != NULL) + { + *unit_type = (int)info_ptr->phys_unit_type; + retval |= PNG_INFO_pHYs; + } + return (retval); } return (0); } @@ -251,7 +275,7 @@ png_get_text(png_structp png_ptr, png_infop info_ptr, png_textp *text_ptr, *text_ptr = info_ptr->text; if (num_text != NULL) *num_text = info_ptr->num_text; - return (info_ptr->num_text); + return ((png_uint_32)info_ptr->num_text); } return(0); } @@ -1,15 +1,16 @@ /* pngmem.c - stub functions for memory allocation - - libpng 1.0 beta 6 - version 0.96 - For conditions of distribution and use, see copyright notice in png.h - Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. - Copyright (c) 1996, 1997 Andreas Dilger - May 12, 1997 - - This file provides a location for all memory allocation. Users which - need special memory handling are expected to modify the code in this file - to meet their needs. See the instructions at each function. */ + * + * libpng 1.00.97 + * For conditions of distribution and use, see copyright notice in png.h + * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. + * Copyright (c) 1996, 1997 Andreas Dilger + * May 28, 1997 + * + * This file provides a location for all memory allocation. Users which + * need special memory handling are expected to modify the code in this file + * to meet their needs. See the instructions at each function. + */ #define PNG_INTERNAL #include "png.h" @@ -81,7 +82,7 @@ png_malloc(png_structp png_ptr, png_uint_32 size) png_error(png_ptr, "Cannot Allocate > 64K"); #endif - if (size == (png_uint_32)(65536L)) + if (size == (png_uint_32)65536L) { if (png_ptr->offset_table == NULL) { @@ -139,7 +140,7 @@ png_malloc(png_structp png_ptr, png_uint_32 size) for (i = 0; i < num_blocks; i++) { png_ptr->offset_table_ptr[i] = (png_bytep)hptr; - hptr += 65536L; + hptr += (png_uint_32)65536L; } png_ptr->offset_table_number = num_blocks; diff --git a/pngpread.c b/pngpread.c index 2fb1bd623..a33351389 100644 --- a/pngpread.c +++ b/pngpread.c @@ -1,12 +1,12 @@ /* pngpread.c - read a png file in push mode - - libpng 1.0 beta 6 - version 0.96 - For conditions of distribution and use, see copyright notice in png.h - Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. - Copyright (c) 1996, 1997 Andreas Dilger - May 12, 1997 - */ + * + * libpng 1.00.97 + * For conditions of distribution and use, see copyright notice in png.h + * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. + * Copyright (c) 1996, 1997 Andreas Dilger + * May 28, 1997 + */ #define PNG_INTERNAL #include "png.h" @@ -116,10 +116,11 @@ void png_push_read_chunk(png_structp png_ptr, png_infop info_ptr) { /* First we make sure we have enough data for the 4 byte chunk name - and the 4 byte chunk length before proceeding with decoding the - chunk data. To fully decode each of these chunks, we also make - sure we have enough data in the buffer for the 4 byte CRC at the - end of every chunk (except IDAT, which is handled separately). */ + * and the 4 byte chunk length before proceeding with decoding the + * chunk data. To fully decode each of these chunks, we also make + * sure we have enough data in the buffer for the 4 byte CRC at the + * end of every chunk (except IDAT, which is handled separately). + */ if (!(png_ptr->flags & PNG_FLAG_HAVE_CHUNK_HEADER)) { png_byte chunk_length[4]; @@ -160,8 +161,9 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr) else if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4)) { /* If we reach an IDAT chunk, this means we have read all of the - header chunks, and we can start reading the image (or if this - is called after the image has been read - we have an error). */ + * header chunks, and we can start reading the image (or if this + * is called after the image has been read - we have an error). + */ if (png_ptr->mode & PNG_HAVE_IDAT) { if (png_ptr->push_length == 0) @@ -227,6 +229,18 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr) png_handle_cHRM(png_ptr, info_ptr, png_ptr->push_length); } #endif +#if defined(PNG_READ_sRGB_SUPPORTED) + else if (!png_memcmp(png_ptr->chunk_name, png_sRGB, 4)) + { + if (png_ptr->push_length + 4 > png_ptr->buffer_size) + { + png_push_save_buffer(png_ptr); + return; + } + + png_handle_sRGB(png_ptr, info_ptr, png_ptr->push_length); + } +#endif #if defined(PNG_READ_tRNS_SUPPORTED) else if (!png_memcmp(png_ptr->chunk_name, png_tRNS, 4)) { @@ -783,11 +797,11 @@ png_push_handle_tEXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length #ifdef PNG_MAX_MALLOC_64K png_ptr->skip_length = 0; /* This may not be necessary */ - if (length > 65535L) /* We can't hold the entire string in memory */ + if (length > (png_uint_32)65535L) /* Can't hold the entire string in memory */ { png_warning(png_ptr, "tEXt chunk too large to fit in memory"); - png_ptr->skip_length = length - 65535L; - length = 65535L; + png_ptr->skip_length = length - (png_uint_32)65535L; + length = (png_uint_32)65535L; } #endif @@ -866,7 +880,7 @@ png_push_handle_zTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length * to be able to store the uncompressed data. Actually, the threshold * is probably around 32K, but it isn't as definite as 64K is. */ - if (length > 65535L) + if (length > (png_uint_32)65535L) { png_warning(png_ptr, "zTXt chunk too large to fit in memory"); png_push_crc_skip(png_ptr, length); @@ -1029,11 +1043,12 @@ png_push_read_zTXt(png_structp png_ptr, png_infop info_ptr) #endif /* This function is called when we haven't found a handler for this - chunk. In the future we will have code here which can handle - user-defined callback functions for unknown chunks before they are - ignored or cause an error. If there isn't a problem with the - chunk itself (ie a bad chunk name or a critical chunk), the chunk - is (currently) silently ignored. */ + * chunk. In the future we will have code here which can handle + * user-defined callback functions for unknown chunks before they are + * ignored or cause an error. If there isn't a problem with the + * chunk itself (ie a bad chunk name or a critical chunk), the chunk + * is (currently) silently ignored. + */ void png_push_handle_unknown(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) { @@ -1,19 +1,22 @@ /* pngread.c - read a PNG file - - libpng 1.0 beta 6 - version 0.96 - For conditions of distribution and use, see copyright notice in png.h - Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. - Copyright (c) 1996, 1997 Andreas Dilger - May 12, 1997 - */ + * + * libpng 1.00.97 + * For conditions of distribution and use, see copyright notice in png.h + * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. + * Copyright (c) 1996, 1997 Andreas Dilger + * May 28, 1997 + * + * This file contains routines that an application calls directly to + * read a PNG file or stream. + */ #define PNG_INTERNAL #include "png.h" /* Create a PNG structure for reading, and allocate any memory needed. */ png_structp -png_create_read_struct(png_charp user_png_ver, png_voidp error_ptr, +png_create_read_struct(png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn, png_error_ptr warn_fn) { png_structp png_ptr; @@ -76,7 +79,6 @@ png_create_read_struct(png_charp user_png_ver, png_voidp error_ptr, return (png_ptr); } - /* Initialize PNG structure for reading, and allocate any memory needed. This interface is depreciated in favour of the png_create_read_struct(), and it will eventually disappear. */ @@ -215,6 +217,10 @@ png_read_info(png_structp png_ptr, png_infop info_ptr) else if (!png_memcmp(png_ptr->chunk_name, png_sBIT, 4)) png_handle_sBIT(png_ptr, info_ptr, length); #endif +#if defined(PNG_READ_sRGB_SUPPORTED) + else if (!png_memcmp(png_ptr->chunk_name, png_sRGB, 4)) + png_handle_sRGB(png_ptr, info_ptr, length); +#endif #if defined(PNG_READ_tEXt_SUPPORTED) else if (!png_memcmp(png_ptr->chunk_name, png_tEXt, 4)) png_handle_tEXt(png_ptr, info_ptr, length); @@ -247,10 +253,11 @@ png_read_update_info(png_structp png_ptr, png_infop info_ptr) png_read_transform_info(png_ptr, info_ptr); } -/* initialize palette, background, etc, after transformations - are set, but before any reading takes place. This allows - the user to obtail a gamma corrected palette, for example. - If the user doesn't call this, we will do it ourselves. */ +/* Initialize palette, background, etc, after transformations + * are set, but before any reading takes place. This allows + * the user to obtail a gamma corrected palette, for example. + * If the user doesn't call this, we will do it ourselves. + */ void png_start_read_image(png_structp png_ptr) { @@ -439,23 +446,26 @@ png_read_row(png_structp png_ptr, png_bytep row, png_bytep dsp_row) } /* Read one or more rows of image data. If the image is interlaced, - and png_set_interlace_handling() has been called, the rows need to - to contain the contents of the rows from the previous pass. If - the image has alpha or transparency, and png_handle_alpha() has been - called, the rows contents must be initialized to the contents of the - screen. "row" holds the actual image, and pixels are placed in it - as they arrive. If the image is displayed after each pass, it will - appear to "sparkle" in. "display_row" can be used to display a - "chunky" progressive image, with finer detail added as it becomes - available. If you do not want this "chunky" display, you may pass - NULL for display_row. If you do not want the sparkle display, and - you have not called png_handle_alpha(), you may pass NULL for rows. - If you have called png_handle_alpha(), and the image has either an - alpha channel or a transparency chunk, you must provide a buffer for - rows. In this case, you do not have to provide a display_row buffer - also, but you may. If the image is not interlaced, or if you have - not called png_set_interlace_handling(), the display_row buffer will - be ignored, so pass NULL to it. */ + * and png_set_interlace_handling() has been called, the rows need to + * contain the contents of the rows from the previous pass. If the + * image has alpha or transparency, and png_handle_alpha() has been + * called, the rows contents must be initialized to the contents of the + * screen. + * + * "row" holds the actual image, and pixels are placed in it + * as they arrive. If the image is displayed after each pass, it will + * appear to "sparkle" in. "display_row" can be used to display a + * "chunky" progressive image, with finer detail added as it becomes + * available. If you do not want this "chunky" display, you may pass + * NULL for display_row. If you do not want the sparkle display, and + * you have not called png_handle_alpha(), you may pass NULL for rows. + * If you have called png_handle_alpha(), and the image has either an + * alpha channel or a transparency chunk, you must provide a buffer for + * rows. In this case, you do not have to provide a display_row buffer + * also, but you may. If the image is not interlaced, or if you have + * not called png_set_interlace_handling(), the display_row buffer will + * be ignored, so pass NULL to it. + */ void png_read_rows(png_structp png_ptr, png_bytepp row, @@ -491,14 +501,15 @@ png_read_rows(png_structp png_ptr, png_bytepp row, } /* Read the entire image. If the image has an alpha channel or a tRNS - chunk, and you have called png_handle_alpha(), you will need to - initialize the image to the current image that PNG will be overlaying. - We set the num_rows again here, in case it was incorrectly set in - png_read_start_row() by a call to png_read_update_info() or - png_start_read_image() if png_set_interlace_handling() wasn't called - prior to either of these functions like it should have been. You can - only call this function once. If you desire to have an image for - each pass of a interlaced image, use png_read_rows() instead */ + * chunk, and you have called png_handle_alpha(), you will need to + * initialize the image to the current image that PNG will be overlaying. + * We set the num_rows again here, in case it was incorrectly set in + * png_read_start_row() by a call to png_read_update_info() or + * png_start_read_image() if png_set_interlace_handling() wasn't called + * prior to either of these functions like it should have been. You can + * only call this function once. If you desire to have an image for + * each pass of a interlaced image, use png_read_rows() instead. + */ void png_read_image(png_structp png_ptr, png_bytepp image) { @@ -524,8 +535,9 @@ png_read_image(png_structp png_ptr, png_bytepp image) } /* Read the end of the PNG file. Will not read past the end of the - file, will verify the end is accurate, and will read any comments - or time information at the end of the file, if info is not NULL. */ + * file, will verify the end is accurate, and will read any comments + * or time information at the end of the file, if info is not NULL. + */ void png_read_end(png_structp png_ptr, png_infop info_ptr) { @@ -594,6 +606,10 @@ png_read_end(png_structp png_ptr, png_infop info_ptr) else if (!png_memcmp(png_ptr->chunk_name, png_sBIT, 4)) png_handle_sBIT(png_ptr, info_ptr, length); #endif +#if defined(PNG_READ_sRGB_SUPPORTED) + else if (!png_memcmp(png_ptr->chunk_name, png_sRGB, 4)) + png_handle_sRGB(png_ptr, info_ptr, length); +#endif #if defined(PNG_READ_tEXt_SUPPORTED) else if (!png_memcmp(png_ptr->chunk_name, png_tEXt, 4)) png_handle_tEXt(png_ptr, info_ptr, length); @@ -659,7 +675,6 @@ png_destroy_read_struct(png_structpp png_ptr_ptr, png_infopp info_ptr_ptr, void png_read_destroy(png_structp png_ptr, png_infop info_ptr, png_infop end_info_ptr) { - int i; jmp_buf tmp_jmp; png_error_ptr error_fn; png_error_ptr warning_fn; @@ -700,6 +715,7 @@ png_read_destroy(png_structp png_ptr, png_infop info_ptr, png_infop end_info_ptr #if defined(PNG_READ_GAMMA_SUPPORTED) if (png_ptr->gamma_16_table != NULL) { + int i; for (i = 0; i < (1 << (8 - png_ptr->gamma_shift)); i++) { png_free(png_ptr, png_ptr->gamma_16_table[i]); @@ -710,6 +726,7 @@ png_read_destroy(png_structp png_ptr, png_infop info_ptr, png_infop end_info_ptr png_free(png_ptr, png_ptr->gamma_16_table); if (png_ptr->gamma_16_from_1 != NULL) { + int i; for (i = 0; i < (1 << (8 - png_ptr->gamma_shift)); i++) { png_free(png_ptr, png_ptr->gamma_16_from_1[i]); @@ -718,6 +735,7 @@ png_read_destroy(png_structp png_ptr, png_infop info_ptr, png_infop end_info_ptr png_free(png_ptr, png_ptr->gamma_16_from_1); if (png_ptr->gamma_16_to_1 != NULL) { + int i; for (i = 0; i < (1 << (8 - png_ptr->gamma_shift)); i++) { png_free(png_ptr, png_ptr->gamma_16_to_1[i]); @@ -1,18 +1,19 @@ /* pngrio.c - functions for data input - - libpng 1.0 beta 6 - version 0.96 - For conditions of distribution and use, see copyright notice in png.h - Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. - Copyright (c) 1996, 1997 Andreas Dilger - May 12, 1997 - - This file provides a location for all input. Users which need - special handling are expected to write a function which has the same - arguments as this, and perform a similar function, but possibly has - a different input method. Note that you shouldn't change this - function, but rather write a replacement function and then make - libpng use it at run time with png_set_read_fn(...) */ + * + * libpng 1.00.97 + * For conditions of distribution and use, see copyright notice in png.h + * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. + * Copyright (c) 1996, 1997 Andreas Dilger + * May 28, 1997 + * + * This file provides a location for all input. Users which need + * special handling are expected to write a function which has the same + * arguments as this, and perform a similar function, but possibly has + * a different input method. Note that you shouldn't change this + * function, but rather write a replacement function and then make + * libpng use it at run time with png_set_read_fn(...). + */ #define PNG_INTERNAL #include "png.h" diff --git a/pngrtran.c b/pngrtran.c index 8df7d1f8f..28b041509 100644 --- a/pngrtran.c +++ b/pngrtran.c @@ -1,22 +1,28 @@ /* pngrtran.c - transforms the data in a row for PNG readers - - libpng 1.0 beta 6 - version 0.96 - For conditions of distribution and use, see copyright notice in png.h - Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. - Copyright (c) 1996, 1997 Andreas Dilger - May 12, 1997 - */ + * + * libpng 1.00.97 + * For conditions of distribution and use, see copyright notice in png.h + * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. + * Copyright (c) 1996, 1997 Andreas Dilger + * May 28, 1997 + * + * This file contains functions optionally called by an application + * in order to tell libpng how to handle data when reading a PNG. + * Transformations which are used in both reading and writing are + * in pngtrans.c. + */ #define PNG_INTERNAL #include "png.h" #ifdef PNG_READ_COMPOSITE_NODIV_SUPPORTED /* With these routines, we avoid an integer divide, which will be slower on - many machines. However, it does take more operations than the corresponding - divide method, so it may be slower on some RISC systems. There are two - shifts (by 8 or 16 bits) and an addition, versus a single integer divide. - The results may also be off by one for certain values. */ + * many machines. However, it does take more operations than the corresponding + * divide method, so it may be slower on some RISC systems. There are two + * shifts (by 8 or 16 bits) and an addition, versus a single integer divide. + * The results may also be off by one for certain values. + */ /* pixel and background should be in gamma 1.0 space */ #define png_composite(composite, pixel, trans, background) \ @@ -42,9 +48,62 @@ #define png_composite_16(composite, pixel, trans, background) \ (composite) = (png_uint_16)(((png_uint_32)(pixel) * (png_uint_32)(trans) + \ (png_uint_32)(background)*(png_uint_32)(65535L - (png_uint_32)(trans)) + \ - (png_uint_32)32767) / 65535L) + (png_uint_32)32767) / (png_uint_32)65535L) #endif +/* Set the action on getting a CRC error for an ancillary or critical chunk. */ +void +png_set_crc_action(png_structp png_ptr, int crit_action, int ancil_action) +{ + png_debug(1, "in png_set_crc_action\n"); + /* Tell libpng how we react to CRC errors in critical chunks */ + switch (crit_action) + { + case PNG_CRC_NO_CHANGE: /* leave setting as is */ + break; + case PNG_CRC_WARN_USE: /* warn/use data */ + png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK; + png_ptr->flags |= PNG_FLAG_CRC_CRITICAL_USE; + break; + case PNG_CRC_QUIET_USE: /* quiet/use data */ + png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK; + png_ptr->flags |= PNG_FLAG_CRC_CRITICAL_USE | + PNG_FLAG_CRC_CRITICAL_IGNORE; + break; + case PNG_CRC_WARN_DISCARD: /* not a valid action for critical data */ + png_warning(png_ptr, "Can't discard critical data on CRC error."); + case PNG_CRC_ERROR_QUIT: /* error/quit */ + case PNG_CRC_DEFAULT: + default: + png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK; + break; + } + + switch (ancil_action) + { + case PNG_CRC_NO_CHANGE: /* leave setting as is */ + break; + case PNG_CRC_WARN_USE: /* warn/use data */ + png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK; + png_ptr->flags |= PNG_FLAG_CRC_ANCILLARY_USE; + break; + case PNG_CRC_QUIET_USE: /* quiet/use data */ + png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK; + png_ptr->flags |= PNG_FLAG_CRC_ANCILLARY_USE | + PNG_FLAG_CRC_ANCILLARY_NOWARN; + break; + case PNG_CRC_ERROR_QUIT: /* error/quit */ + png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK; + png_ptr->flags |= PNG_FLAG_CRC_ANCILLARY_NOWARN; + break; + case PNG_CRC_WARN_DISCARD: /* warn/discard data */ + case PNG_CRC_DEFAULT: + default: + png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK; + break; + } +} + #if defined(PNG_READ_BACKGROUND_SUPPORTED) /* handle alpha and tRNS via a background color */ void @@ -89,12 +148,13 @@ png_set_strip_alpha(png_structp png_ptr) #if defined(PNG_READ_DITHER_SUPPORTED) /* Dither file to 8 bit. Supply a palette, the current number - of elements in the palette, the maximum number of elements - allowed, and a histogram if possible. If the current number - of colors is greater then the maximum number, the palette will be - modified to fit in the maximum number. "full_dither" indicates - whether we need a dithering cube set up for RGB images, or if we - simply are reducing the number of colors in a paletted image. */ + * of elements in the palette, the maximum number of elements + * allowed, and a histogram if possible. If the current number + * of colors is greater then the maximum number, the palette will be + * modified to fit in the maximum number. "full_dither" indicates + * whether we need a dithering cube set up for RGB images, or if we + * simply are reducing the number of colors in a paletted image. + */ typedef struct png_dsort_struct { @@ -478,9 +538,10 @@ png_set_dither(png_structp png_ptr, png_colorp palette, #if defined(PNG_READ_GAMMA_SUPPORTED) /* Transform the image from the file_gamma to the screen_gamma. We - only do transformations on images where the file_gamma and screen_gamma - are not close reciprocals, otherwise it slows things down slightly, and - also needlessly introduces small errors. */ + * only do transformations on images where the file_gamma and screen_gamma + * are not close reciprocals, otherwise it slows things down slightly, and + * also needlessly introduces small errors. + */ void png_set_gamma(png_structp png_ptr, double screen_gamma, double file_gamma) { @@ -494,8 +555,9 @@ png_set_gamma(png_structp png_ptr, double screen_gamma, double file_gamma) #if defined(PNG_READ_EXPAND_SUPPORTED) /* Expand paletted images to rgb, expand grayscale images of - less then 8 bit depth to 8 bit depth, and expand tRNS chunks - to alpha channels. */ + * less then 8 bit depth to 8 bit depth, and expand tRNS chunks + * to alpha channels. + */ void png_set_expand(png_structp png_ptr) { @@ -515,8 +577,9 @@ png_set_gray_to_rgb(png_structp png_ptr) #if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED) /* Convert a RGB image to a grayscale of the given width. This would - allow us, for example, to convert a 24 bpp RGB image into an 8 or - 16 bpp grayscale image. (Not yet implemented.) */ + * allow us, for example, to convert a 24 bpp RGB image into an 8 or + * 16 bpp grayscale image. (Not yet implemented.) + */ void png_set_rgb_to_gray(png_structp png_ptr, int gray_bits) { @@ -527,7 +590,8 @@ png_set_rgb_to_gray(png_structp png_ptr, int gray_bits) #endif /* Initialize everything needed for the read. This includes modifying - the palette */ + * the palette. + */ void png_init_read_transformations(png_structp png_ptr) { @@ -810,8 +874,9 @@ png_init_read_transformations(png_structp png_ptr) } /* Modify the info structure to reflect the transformations. The - info should be updated so a PNG file could be written with it, - assuming the transformations result in valid PNG data. */ + * info should be updated so a PNG file could be written with it, + * assuming the transformations result in valid PNG data. + */ void png_read_transform_info(png_structp png_ptr, png_infop info_ptr) { @@ -910,9 +975,10 @@ png_read_transform_info(png_structp png_ptr, png_infop info_ptr) (png_size_t)((info_ptr->width * info_ptr->pixel_depth + 7) >> 3); } -/* transform the row. The order of transformations is significant, - and is very touchy. If you add a transformation, take care to - decide how it fits in with the other transformations here. */ +/* Transform the row. The order of transformations is significant, + * and is very touchy. If you add a transformation, take care to + * decide how it fits in with the other transformations here. + */ void png_do_read_transformations(png_structp png_ptr) { @@ -955,7 +1021,9 @@ png_do_read_transformations(png_structp png_ptr) #endif #if defined(PNG_READ_BACKGROUND_SUPPORTED) - if (png_ptr->transformations & PNG_BACKGROUND) + if ((png_ptr->transformations & PNG_BACKGROUND) && + ((png_ptr->num_trans != 0 ) || + (png_ptr->color_type & PNG_COLOR_MASK_ALPHA))) png_do_background(&(png_ptr->row_info), png_ptr->row_buf + 1, &(png_ptr->trans_values), &(png_ptr->background), &(png_ptr->background_1), @@ -1041,11 +1109,12 @@ png_do_read_transformations(png_structp png_ptr) } #if defined(PNG_READ_PACK_SUPPORTED) -/* unpack pixels of 1, 2, or 4 bits per pixel into 1 byte per pixel, - without changing the actual values. Thus, if you had a row with - a bit depth of 1, you would end up with bytes that only contained - the numbers 0 or 1. If you would rather they contain 0 and 255, use - png_do_shift() after this. */ +/* Unpack pixels of 1, 2, or 4 bits per pixel into 1 byte per pixel, + * without changing the actual values. Thus, if you had a row with + * a bit depth of 1, you would end up with bytes that only contained + * the numbers 0 or 1. If you would rather they contain 0 and 255, use + * png_do_shift() after this. + */ void png_do_unpack(png_row_infop row_info, png_bytep row) { @@ -1131,10 +1200,11 @@ png_do_unpack(png_row_infop row_info, png_bytep row) #endif #if defined(PNG_READ_SHIFT_SUPPORTED) -/* reverse the effects of png_do_shift. This routine merely shifts the - pixels back to their significant bits values. Thus, if you have - a row of bit depth 8, but only 5 are significant, this will shift - the values back to 0 through 31 */ +/* Reverse the effects of png_do_shift. This routine merely shifts the + * pixels back to their significant bits values. Thus, if you have + * a row of bit depth 8, but only 5 are significant, this will shift + * the values back to 0 through 31. + */ void png_do_unshift(png_row_infop row_info, png_bytep row, png_color_8p sig_bits) { @@ -1268,7 +1338,7 @@ png_do_chop(png_row_infop row_info, png_bytep row) * * What the ideal calculation should be: *dp = (((((png_uint_32)(*sp) << 8) | - (png_uint_32)(*(sp + 1))) * 255 + 127) / 65535; + (png_uint_32)(*(sp + 1))) * 255 + 127) / (png_uint_32)65535L; * Approximate calculation with shift/add instead of multiply/divide: *dp = ((((png_uint_32)(*sp) << 8) | @@ -1527,10 +1597,11 @@ png_do_gray_to_rgb(png_row_infop row_info, png_bytep row) } #endif -/* build a grayscale palette. Palette is assumed to be 1 << bit_depth - large of png_color. This lets grayscale images be treated as - paletted. Most useful for gamma correction and simplification - of code. */ +/* Build a grayscale palette. Palette is assumed to be 1 << bit_depth + * large of png_color. This lets grayscale images be treated as + * paletted. Most useful for gamma correction and simplification + * of code. + */ void png_build_grayscale_palette(int bit_depth, png_colorp palette) { @@ -1762,8 +1833,9 @@ png_correct_palette(png_structp png_ptr, png_colorp palette, #if defined(PNG_READ_BACKGROUND_SUPPORTED) /* Replace any alpha or transparency with the supplied background color. - "background" is already in the screen gamma, while "background_1" is - at a gamma of 1.0. Paletted files have already been taken care of. */ + * "background" is already in the screen gamma, while "background_1" is + * at a gamma of 1.0. Paletted files have already been taken care of. + */ void png_do_background(png_row_infop row_info, png_bytep row, png_color_16p trans_values, png_color_16p background, @@ -2330,7 +2402,7 @@ png_do_background(png_row_infop row_info, png_bytep row, png_composite_16(v, g, a, background->green); *(dp + 2) = (png_byte)((v >> 8) & 0xff); *(dp + 3) = (png_byte)(v & 0xff); - png_composite_16(v, g, a, background->green); + png_composite_16(v, b, a, background->blue); *(dp + 4) = (png_byte)((v >> 8) & 0xff); *(dp + 5) = (png_byte)(v & 0xff); } @@ -2356,10 +2428,11 @@ png_do_background(png_row_infop row_info, png_bytep row, #if defined(PNG_READ_GAMMA_SUPPORTED) /* Gamma correct the image, avoiding the alpha channel. Make sure - you do this after you deal with the trasparency issue on grayscale - or rgb images. If your bit depth is 8, use gamma_table, if it - is 16, use gamma_16_table and gamma_shift. Build these with - build_gamma_table(). */ + * you do this after you deal with the trasparency issue on grayscale + * or rgb images. If your bit depth is 8, use gamma_table, if it + * is 16, use gamma_16_table and gamma_shift. Build these with + * build_gamma_table(). + */ void png_do_gamma(png_row_infop row_info, png_bytep row, png_bytep gamma_table, png_uint_16pp gamma_16_table, @@ -2488,8 +2561,8 @@ png_do_gamma(png_row_infop row_info, png_bytep row, int msb = *sp & 0xf0; int lsb = *sp & 0x0f; - *sp = (((int)gamma_table[msb | msb >> 4] + 8) & 0xf0) | - (((int)gamma_table[lsb << 4 | lsb] + 8) >> 4); + *sp = (((int)gamma_table[msb | (msb >> 4)]) & 0xf0) | + (((int)gamma_table[(lsb << 4) | lsb]) >> 4); sp++; } } @@ -2521,8 +2594,9 @@ png_do_gamma(png_row_infop row_info, png_bytep row, #endif #if defined(PNG_READ_EXPAND_SUPPORTED) -/* expands a palette row to an rgb or rgba row depending - upon whether you supply trans and num_trans */ +/* Expands a palette row to an rgb or rgba row depending + * upon whether you supply trans and num_trans. + */ void png_do_expand_palette(png_row_infop row_info, png_bytep row, png_colorp palette, png_bytep trans, int num_trans) @@ -2662,8 +2736,9 @@ png_do_expand_palette(png_row_infop row_info, png_bytep row, } } -/* if the bit depth < 8, it is expanded to 8. Also, if the - transparency value is supplied, an alpha channel is built. */ +/* If the bit depth < 8, it is expanded to 8. Also, if the + * transparency value is supplied, an alpha channel is built. + */ void png_do_expand(png_row_infop row_info, png_bytep row, png_color_16p trans_value) @@ -2958,9 +3033,10 @@ static int png_gamma_shift[] = {0x10, 0x21, 0x42, 0x84, 0x110, 0x248, 0x550, 0xff0}; /* We build the 8- or 16-bit gamma tables here. Note that for 16-bit - tables, we don't make a full table if we are reducing to 8-bit in - the future. Note also how the gamma_16 tables are segmented so that - we don't need to allocate > 64K chunks for a full 16-bit table. */ + * tables, we don't make a full table if we are reducing to 8-bit in + * the future. Note also how the gamma_16 tables are segmented so that + * we don't need to allocate > 64K chunks for a full 16-bit table. + */ void png_build_gamma_table(png_structp png_ptr) { diff --git a/pngrutil.c b/pngrutil.c index f018526be..bd225b6ca 100644 --- a/pngrutil.c +++ b/pngrutil.c @@ -1,12 +1,15 @@ /* pngrutil.c - utilities to read a PNG file - - libpng 1.0 beta 6 - version 0.96 - For conditions of distribution and use, see copyright notice in png.h - Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. - Copyright (c) 1996, 1997 Andreas Dilger - May 12, 1997 - */ + * + * libpng 1.00.97 + * For conditions of distribution and use, see copyright notice in png.h + * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. + * Copyright (c) 1996, 1997 Andreas Dilger + * May 28, 1997 + * + * This file contains routines which are only called from within + * libpng itself during the course of reading an image. + */ #define PNG_INTERNAL #include "png.h" @@ -57,59 +60,6 @@ png_get_uint_16(png_bytep buf) } #endif /* PNG_READ_BIG_ENDIAN_SUPPORTED */ -/* Set the action on getting a CRC error for an ancillary or critical chunk. */ -void -png_set_crc_action(png_structp png_ptr, int crit_action, int ancil_action) -{ - png_debug(1, "in png_set_crc_action\n"); - /* Tell libpng how we react to CRC errors in critical chunks */ - switch (crit_action) - { - case PNG_CRC_NO_CHANGE: /* leave setting as is */ - break; - case PNG_CRC_WARN_USE: /* warn/use data */ - png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK; - png_ptr->flags |= PNG_FLAG_CRC_CRITICAL_USE; - break; - case PNG_CRC_QUIET_USE: /* quiet/use data */ - png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK; - png_ptr->flags |= PNG_FLAG_CRC_CRITICAL_USE | - PNG_FLAG_CRC_CRITICAL_IGNORE; - break; - case PNG_CRC_WARN_DISCARD: /* not a valid action for critical data */ - png_warning(png_ptr, "Can't discard critical data on CRC error."); - case PNG_CRC_ERROR_QUIT: /* error/quit */ - case PNG_CRC_DEFAULT: - default: - png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK; - break; - } - - switch (ancil_action) - { - case PNG_CRC_NO_CHANGE: /* leave setting as is */ - break; - case PNG_CRC_WARN_USE: /* warn/use data */ - png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK; - png_ptr->flags |= PNG_FLAG_CRC_ANCILLARY_USE; - break; - case PNG_CRC_QUIET_USE: /* quiet/use data */ - png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK; - png_ptr->flags |= PNG_FLAG_CRC_ANCILLARY_USE | - PNG_FLAG_CRC_ANCILLARY_NOWARN; - break; - case PNG_CRC_ERROR_QUIT: /* error/quit */ - png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK; - png_ptr->flags |= PNG_FLAG_CRC_ANCILLARY_NOWARN; - break; - case PNG_CRC_WARN_DISCARD: /* warn/discard data */ - case PNG_CRC_DEFAULT: - default: - png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK; - break; - } -} - /* Read data, and (optionally) run it through the CRC. */ void png_crc_read(png_structp png_ptr, png_bytep buf, png_size_t length) @@ -185,11 +135,7 @@ png_crc_error(png_structp png_ptr) if (need_crc) { crc = png_get_uint_32(crc_bytes); -#ifdef PNG_USE_OWN_CRC - return (((crc^0xffffffffL)&0xffffffffL) != (png_ptr->crc&0xffffffffL)); -#else return (crc != png_ptr->crc); -#endif } else return 0; @@ -228,7 +174,8 @@ png_handle_IHDR(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) interlace_type = buf[12]; /* check for width and height valid values */ - if (width == 0 || width > 2147483647 || height == 0 || height > 2147483647) + if (width == 0 || width > (png_uint_32)2147483647L || height == 0 || + height > (png_uint_32)2147483647L) png_error(png_ptr, "Invalid image size in IHDR"); /* check other values */ @@ -246,7 +193,7 @@ png_handle_IHDR(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) color_type == PNG_COLOR_TYPE_RGB_ALPHA) && bit_depth < 8)) png_error(png_ptr, "Invalid color type/bit depth combination in IHDR"); - if (interlace_type > PNG_INTERLACE_ADAM7) + if (interlace_type >= PNG_INTERLACE_LAST) png_error(png_ptr, "Unknown interlace method in IHDR"); if (compression_type != PNG_COMPRESSION_TYPE_BASE) @@ -337,7 +284,7 @@ png_handle_PLTE(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) } num = (int)length / 3; - palette = (png_colorp)png_malloc(png_ptr, num * sizeof (png_color)); + palette = (png_colorp)png_zalloc(png_ptr, num, sizeof (png_color)); png_ptr->flags |= PNG_FLAG_FREE_PALETTE; for (i = 0; i < num; i++) { @@ -457,6 +404,26 @@ png_handle_gAMA(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) if (igamma == 0) return; +#if defined(PNG_READ_sRGB_SUPPORTED) + if ((png_ptr->mode & PNG_HAVE_sRGB)) + if(igamma != 50000) + { + png_warning(png_ptr, + "Ignoring incorrect gAMA value when sRGB is also present"); + return; + } +#endif /* PNG_READ_sRGB_SUPPORTED */ + +#if defined(PNG_READ_sRGB_SUPPORTED) + if (png_ptr->mode & PNG_HAVE_sRGB) + if(igamma != 50000) + { + png_warning(png_ptr, + "Ignoring incorrect gAMA value when sRGB is also present"); + return; + } +#endif /* PNG_READ_sRGB_SUPPORTED */ + file_gamma = (float)igamma / (float)100000.0; png_ptr->gamma = file_gamma; png_set_gAMA(png_ptr, info_ptr, file_gamma); @@ -483,8 +450,10 @@ png_handle_sBIT(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) return; } else if (png_ptr->mode & PNG_HAVE_PLTE) + { /* Should be an error, but we can cope with it */ png_warning(png_ptr, "Out of place sBIT chunk"); + } else if (info_ptr != NULL && info_ptr->valid & PNG_INFO_sBIT) { png_warning(png_ptr, "Duplicate sBIT chunk"); @@ -545,7 +514,8 @@ png_handle_cHRM(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) else if (png_ptr->mode & PNG_HAVE_PLTE) /* Should be an error, but we can cope with it */ png_warning(png_ptr, "Missing PLTE before cHRM"); - else if (info_ptr != NULL && info_ptr->valid & PNG_INFO_cHRM) + else if (info_ptr != NULL && info_ptr->valid & PNG_INFO_cHRM + && !(info_ptr->valid & PNG_INFO_sRGB)) { png_warning(png_ptr, "Duplicate cHRM chunk"); png_crc_finish(png_ptr, length); @@ -626,11 +596,92 @@ png_handle_cHRM(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) if (png_crc_finish(png_ptr, 0)) return; +#if defined(PNG_READ_sRGB_SUPPORTED) + if ((png_ptr->mode & PNG_HAVE_sRGB)) + if(white_x != .3127 || white_y != .329 || red_x != .64 || red_y != .33 || + green_x != .3 || green_y != .6 || blue_x != .15 || blue_y != .06) + { + png_warning(png_ptr, + "Ignoring incorrect cHRM value when sRGB is also present"); + return; + } +#endif /* PNG_READ_sRGB_SUPPORTED */ + png_set_cHRM(png_ptr, info_ptr, white_x, white_y, red_x, red_y, green_x, green_y, blue_x, blue_y); } #endif +#if defined(PNG_READ_sRGB_SUPPORTED) +void +png_handle_sRGB(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) +{ + png_byte intent; + png_byte buf[1]; + float file_gamma; + float white_x, white_y, red_x, red_y, green_x, green_y, blue_x, blue_y; + + png_debug(1, "in png_handle_sRGB\n"); + + if (!(png_ptr->mode & PNG_HAVE_IHDR)) + png_error(png_ptr, "Missing IHDR before sRGB"); + else if (png_ptr->mode & PNG_HAVE_IDAT) + { + png_warning(png_ptr, "Invalid sRGB after IDAT"); + png_crc_finish(png_ptr, length); + return; + } + else if (png_ptr->mode & PNG_HAVE_PLTE) + /* Should be an error, but we can cope with it */ + png_warning(png_ptr, "Out of place sRGB chunk"); + else if (info_ptr != NULL && info_ptr->valid & PNG_INFO_sRGB) + { + png_warning(png_ptr, "Duplicate sRGB chunk"); + png_crc_finish(png_ptr, length); + return; + } + + if (length != 1) + { + png_warning(png_ptr, "Incorrect sRGB chunk length"); + png_crc_finish(png_ptr, length); + return; + } + + png_crc_read(png_ptr, buf, 1); + if (png_crc_finish(png_ptr, 0)) + return; + + intent = buf[0]; + /* check for bad intent */ + if (intent > 3) + { + png_warning(png_ptr, "Unknown sRGB intent"); + return; + } + + /* if we really want to be paranoid we could check for + already defined gamma and chrm with values that are + inconsistent with sRGB -- for now, just ignore them */ + + file_gamma = 0.45; + png_set_gAMA(png_ptr, info_ptr, file_gamma); + + white_x = 0.3127; + white_y = 0.3290; + red_x = 0.6400; + red_y = 0.3300; + green_x = 0.3000; + green_y = 0.6000; + blue_x = 0.1500; + blue_y = 0.0600; + + png_set_cHRM(png_ptr, info_ptr, + white_x, white_y, red_x, red_y, green_x, green_y, blue_x, blue_y); + + png_set_sRGB(png_ptr, info_ptr, intent); +} +#endif #if defined(PNG_READ_tRNS_SUPPORTED) void png_handle_tRNS(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) @@ -683,7 +734,7 @@ png_handle_tRNS(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) } png_crc_read(png_ptr, buf, (png_size_t)length); - png_ptr->num_trans = 3; + png_ptr->num_trans = 1; png_ptr->trans_values.red = png_get_uint_16(buf); png_ptr->trans_values.green = png_get_uint_16(buf + 2); png_ptr->trans_values.blue = png_get_uint_16(buf + 4); @@ -1113,11 +1164,11 @@ png_handle_tEXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) png_ptr->mode |= PNG_AFTER_IDAT; #ifdef PNG_MAX_MALLOC_64K - if (length > 65535L) + if (length > (png_uint_32)65535L) { png_warning(png_ptr, "tEXt chunk too large to fit in memory"); - skip = length - 65535L; - length = 65535L; + skip = length - (png_uint_32)65535L; + length = (png_uint_32)65535L; } #endif @@ -1171,7 +1222,7 @@ png_handle_zTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) #ifdef PNG_MAX_MALLOC_64K /* We will no doubt have problems with chunks even half this size, but there is no hard and fast rule to tell us where to stop. */ - if (length > 65535L) + if (length > (png_uint_32)65535L) { png_warning(png_ptr,"zTXt chunk too large to fit in memory"); png_crc_finish(png_ptr, length); @@ -2113,13 +2164,13 @@ png_read_start_row(png_structp png_ptr) rowbytes = ((rowbytes * (png_uint_32)max_pixel_depth + 7) >> 3) + 1 + ((max_pixel_depth + 7) >> 3); #ifdef PNG_MAX_MALLOC_64K - if (rowbytes > 65536L) + if (rowbytes > (png_uint_32)65536L) png_error(png_ptr, "This image requires a row greater than 64KB"); #endif png_ptr->row_buf = (png_bytep)png_malloc(png_ptr, rowbytes); #ifdef PNG_MAX_MALLOC_64K - if (png_ptr->rowbytes + 1 > 65536L) + if ((png_uint_32)png_ptr->rowbytes + 1 > (png_uint_32)65536L) png_error(png_ptr, "This image requires a row greater than 64KB"); #endif png_ptr->prev_row = (png_bytep)png_malloc(png_ptr, png_ptr->rowbytes + 1); @@ -1,12 +1,17 @@ /* pngset.c - storage of image information into info struct - - libpng 1.0 beta 6 - version 0.96 - For conditions of distribution and use, see copyright notice in png.h - Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. - Copyright (c) 1996, 1997 Andreas Dilger - May 12, 1997 - */ + * + * libpng 1.00.97 + * For conditions of distribution and use, see copyright notice in png.h + * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. + * Copyright (c) 1996, 1997 Andreas Dilger + * May 28, 1997 + * + * The functions here are used during reads to store data from the file + * into the info struct, and during writes to store application data + * into the info struct for writing into the file. This abstracts the + * info struct and allows us to change the structure in the future. + */ #define PNG_INTERNAL #include "png.h" @@ -205,8 +210,57 @@ png_set_sBIT(png_structp png_ptr, png_infop info_ptr, } #endif -#if defined(PNG_READ_tEXt_SUPPORTED) || defined(PNG_WRITE_zTXt_SUPPORTED) || \ - defined(PNG_READ_tEXt_SUPPORTED) || defined(PNG_WRITE_zTXt_SUPPORTED) +#if defined(PNG_READ_sRGB_SUPPORTED) || defined(PNG_WRITE_sRGB_SUPPORTED) +void +png_set_sRGB(png_structp png_ptr, png_infop info_ptr, png_byte intent) +{ + png_debug1(1, "in %s storage function\n", "sRGB"); + if (info_ptr == NULL) + return; + + info_ptr->srgb_intent = intent; + info_ptr->valid |= PNG_INFO_sRGB; +} +void +png_set_sRGB_gAMA_and_cHRM(png_structp png_ptr, png_infop info_ptr, + png_byte intent) +{ +#if defined(PNG_READ_gAMA_SUPPORTED) || defined(PNG_WRITE_gAMA_SUPPORTED) + float file_gamma; +#endif +#if defined(PNG_READ_cHRM_SUPPORTED) || defined(PNG_WRITE_cHRM_SUPPORTED) + float white_x, white_y, red_x, red_y, green_x, green_y, blue_x, blue_y; +#endif + png_debug1(1, "in %s storage function\n", "sRGB_gAMA_and_cHRM"); + if (info_ptr == NULL) + return; + + png_set_sRGB(png_ptr, info_ptr, intent); + +#if defined(PNG_READ_gAMA_SUPPORTED) || defined(PNG_WRITE_gAMA_SUPPORTED) + file_gamma = 0.45; + png_set_gAMA(png_ptr, info_ptr, file_gamma); +#endif + +#if defined(PNG_READ_cHRM_SUPPORTED) || defined(PNG_WRITE_cHRM_SUPPORTED) + white_x = 0.3127; + white_y = 0.3290; + red_x = 0.6400; + red_y = 0.3300; + green_x = 0.3000; + green_y = 0.6000; + blue_x = 0.1500; + blue_y = 0.0600; + + png_set_cHRM(png_ptr, info_ptr, + white_x, white_y, red_x, red_y, green_x, green_y, blue_x, blue_y); + +#endif +} +#endif + +#if defined(PNG_READ_tEXt_SUPPORTED) || defined(PNG_WRITE_tEXt_SUPPORTED) || \ + defined(PNG_READ_zTXt_SUPPORTED) || defined(PNG_WRITE_zTXt_SUPPORTED) void png_set_text(png_structp png_ptr, png_infop info_ptr, png_textp text_ptr, int num_text) @@ -304,6 +358,8 @@ png_set_tRNS(png_structp png_ptr, png_infop info_ptr, { png_memcpy(&(info_ptr->trans_values), trans_values, sizeof(png_color_16)); + if (num_trans == 0) + num_trans = 1; } info_ptr->num_trans = (png_uint_16)num_trans; info_ptr->valid |= PNG_INFO_tRNS; @@ -1,12 +1,30 @@ /* pngtest.c - a simple test program to test libpng - - libpng 1.0 beta 6 - version 0.96 - For conditions of distribution and use, see copyright notice in png.h - Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. - Copyright (c) 1996, 1997 Andreas Dilger - May 12, 1997 - */ + * + * libpng 1.00.97 + * For conditions of distribution and use, see copyright notice in png.h + * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. + * Copyright (c) 1996, 1997 Andreas Dilger + * May 28, 1997 + * + * This program reads in a PNG image, writes it out again, and then + * compares the two files. If the files are identical, this shows that + * the basic chunk handling, filtering, and (de)compression code is working + * properly. It does not currently test all of the transforms, although + * it probably should. + * + * The program will fail in certain legitimate cases: + * 1) when the compression level or filter selection method is changed. + * 2) when the chunk size is smaller than 8K. + * 3) unknown ancillary chunks exist in the input file. + * 4) others not listed here... + * In these cases, it is best to check with another tool such as "pngcheck" + * to see what the differences between the two images are. + * + * If a filename is given on the command-line, then this file is used + * for the input, rather than the default "pngtest.png". This allows + * testing a wide variety of files easily. + */ #include <stdio.h> #include <stdlib.h> @@ -28,11 +46,11 @@ /* input and output filenames */ #ifdef RISCOS -char *inname = "pngtest_png"; -char *outname = "pngout_png"; +PNG_CONST char *inname = "pngtest_png"; +PNG_CONST char *outname = "pngout_png"; #else -char *inname = "pngtest.png"; -char *outname = "pngout.png"; +PNG_CONST char *inname = "pngtest.png"; +PNG_CONST char *outname = "pngout.png"; #endif char inbuf[256], outbuf[256]; @@ -182,6 +200,16 @@ main(int argc, char *argv[]) } } #endif +#if defined(PNG_READ_sRGB_SUPPORTED) && defined(PNG_WRITE_sRGB_SUPPORTED) + { + png_byte intent; + + if (png_get_sRGB(read_ptr, read_info_ptr, &intent)) + { + png_set_sRGB(write_ptr, write_info_ptr, intent); + } + } +#endif #if defined(PNG_READ_hIST_SUPPORTED) && defined(PNG_WRITE_hIST_SUPPORTED) { png_uint_16p hist; diff --git a/pngtrans.c b/pngtrans.c index 05e4185a6..99569eeb0 100644 --- a/pngtrans.c +++ b/pngtrans.c @@ -1,12 +1,12 @@ /* pngtrans.c - transforms the data in a row (used by both readers and writers) - - libpng 1.0 beta 6 - version 0.96 - For conditions of distribution and use, see copyright notice in png.h - Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. - Copyright (c) 1996, 1997 Andreas Dilger - May 12, 1997 - */ + * + * libpng 1.00.97 + * For conditions of distribution and use, see copyright notice in png.h + * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. + * Copyright (c) 1996, 1997 Andreas Dilger + * May 28, 1997 + */ #define PNG_INTERNAL #include "png.h" @@ -1,18 +1,19 @@ /* pngwio.c - functions for data output - - libpng 1.0 beta 6 - version 0.96 - For conditions of distribution and use, see copyright notice in png.h - Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. - Copyright (c) 1996, 1997 Andreas Dilger - May 12, 1997 - - This file provides a location for all output. Users which need - special handling are expected to write functions which have the same - arguments as these, and perform similar functions, but possibly use - different output methods. Note that you shouldn't change these - functions, but rather write replacement functions and then change - them at run time with png_set_write_fn(...) */ + * + * libpng 1.00.97 + * For conditions of distribution and use, see copyright notice in png.h + * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. + * Copyright (c) 1996, 1997 Andreas Dilger + * May 28, 1997 + * + * This file provides a location for all output. Users which need + * special handling are expected to write functions which have the same + * arguments as these, and perform similar functions, but possibly use + * different output methods. Note that you shouldn't change these + * functions, but rather write replacement functions and then change + * them at run time with png_set_write_fn(...). + */ #define PNG_INTERNAL #include "png.h" diff --git a/pngwrite.c b/pngwrite.c index b571b0f78..584254dff 100644 --- a/pngwrite.c +++ b/pngwrite.c @@ -1,12 +1,12 @@ /* pngwrite.c - general routines to write a PNG file - - libpng 1.0 beta 6 - version 0.96 - For conditions of distribution and use, see copyright notice in png.h - Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. - Copyright (c) 1996, 1997 Andreas Dilger - May 12, 1997 - */ + * + * libpng 1.00.97 + * For conditions of distribution and use, see copyright notice in png.h + * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. + * Copyright (c) 1996, 1997 Andreas Dilger + * May 28, 1997 + */ /* get internal access to png.h */ #define PNG_INTERNAL @@ -38,6 +38,10 @@ png_write_info(png_structp png_ptr, png_infop info_ptr) if (info_ptr->valid & PNG_INFO_gAMA) png_write_gAMA(png_ptr, info_ptr->gamma); #endif +#if defined(PNG_WRITE_sRGB_SUPPORTED) + if (info_ptr->valid & PNG_INFO_sRGB) + png_write_sRGB(png_ptr, info_ptr->srgb_intent); +#endif #if defined(PNG_WRITE_sBIT_SUPPORTED) if (info_ptr->valid & PNG_INFO_sBIT) png_write_sBIT(png_ptr, &(info_ptr->sig_bit), info_ptr->color_type); @@ -128,9 +132,10 @@ png_write_info(png_structp png_ptr, png_infop info_ptr) } /* Writes the end of the PNG file. If you don't want to write comments or - time information, you can pass NULL for info. If you already wrote these - in png_write_info(), do not write them again here. If you have long - comments, I suggest writing them here, and compressing them. */ + * time information, you can pass NULL for info. If you already wrote these + * in png_write_info(), do not write them again here. If you have long + * comments, I suggest writing them here, and compressing them. + */ void png_write_end(png_structp png_ptr, png_infop info_ptr) { @@ -190,6 +195,28 @@ png_write_end(png_structp png_ptr, png_infop info_ptr) png_write_IEND(png_ptr); } +#if defined(PNG_TIME_RFC1152_SUPPORTED) +/* Convert the supplied time into an RFC 1152 string suitable for use in + * a "Creation Time" or other text-based time string. + */ +png_charp +png_convert_to_rfc1152(png_structp png_ptr, png_timep ptime) +{ + const char *short_months[12] = {"Jan", "Feb", "Mar", "Apr", "May", "Jun", + "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"}; + + if (png_ptr->time_buffer == NULL) + { + png_ptr->time_buffer = (png_charp)png_malloc(png_ptr, 29*sizeof(char)); + } + + sprintf(png_ptr->time_buffer, "%d %s %d %02d:%02d:%02d +0000", + ptime->day % 31, short_months[ptime->month], ptime->year, + ptime->hour % 24, ptime->minute % 60, ptime->second % 61); + return png_ptr->time_buffer; +} +#endif /* PNG_TIME_RFC1152_SUPPORTED */ + #if defined(PNG_WRITE_tIME_SUPPORTED) void png_convert_from_struct_tm(png_timep ptime, struct tm FAR * ttime) @@ -261,6 +288,11 @@ png_create_write_struct(png_const_charp user_png_ver, voidp error_ptr, png_set_write_fn(png_ptr, NULL, NULL, NULL); +#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED) + png_set_filter_heuristics(png_ptr, PNG_FILTER_HEURISTIC_DEFAULT, + 1, NULL, NULL); +#endif + return (png_ptr); } @@ -292,10 +324,11 @@ png_write_init(png_structp png_ptr) #endif } -/* write a few rows of image data. If the image is interlaced, - either you will have to write the 7 sub images, or, if you - have called png_set_interlace_handling(), you will have to - "write" the image seven times */ +/* Write a few rows of image data. If the image is interlaced, + * either you will have to write the 7 sub images, or, if you + * have called png_set_interlace_handling(), you will have to + * "write" the image seven times. + */ void png_write_rows(png_structp png_ptr, png_bytepp row, png_uint_32 num_rows) @@ -311,8 +344,9 @@ png_write_rows(png_structp png_ptr, png_bytepp row, } } -/* write the image. You only need to call this function once, even - if you are writing an interlaced image. */ +/* Write the image. You only need to call this function once, even + * if you are writing an interlaced image. + */ void png_write_image(png_structp png_ptr, png_bytepp image) { @@ -339,7 +373,8 @@ png_write_image(png_structp png_ptr, png_bytepp image) void png_write_row(png_structp png_ptr, png_bytep row) { - png_debug(1, "in png_write_row\n"); + png_debug2(1, "in png_write_row (row %ld, pass %d)\n", + png_ptr->row_number, png_ptr->pass); /* initialize transformations and other stuff if first time */ if (png_ptr->row_number == 0 && png_ptr->pass == 0) { @@ -415,12 +450,12 @@ png_write_row(png_structp png_ptr, png_bytep row) png_ptr->row_info.rowbytes = ((png_ptr->row_info.width * (png_uint_32)png_ptr->row_info.pixel_depth + 7) >> 3); - png_debug1(4, "row_info->color_type = %d\n", png_ptr->row_info.color_type); - png_debug1(4, "row_info->width = %d\n", png_ptr->row_info.width); - png_debug1(4, "row_info->channels = %d\n", png_ptr->row_info.channels); - png_debug1(4, "row_info->bit_depth = %d\n", png_ptr->row_info.bit_depth); - png_debug1(4, "row_info->pixel_depth = %d\n", png_ptr->row_info.pixel_depth); - png_debug1(4, "row_info->rowbytes = %d\n", png_ptr->row_info.rowbytes); + png_debug1(3, "row_info->color_type = %d\n", png_ptr->row_info.color_type); + png_debug1(3, "row_info->width = %d\n", png_ptr->row_info.width); + png_debug1(3, "row_info->channels = %d\n", png_ptr->row_info.channels); + png_debug1(3, "row_info->bit_depth = %d\n", png_ptr->row_info.bit_depth); + png_debug1(3, "row_info->pixel_depth = %d\n", png_ptr->row_info.pixel_depth); + png_debug1(3, "row_info->rowbytes = %d\n", png_ptr->row_info.rowbytes); /* Copy user's row into buffer, leaving room for filter byte. */ png_memcpy(png_ptr->row_buf + 1, row, png_ptr->row_info.rowbytes); @@ -527,6 +562,9 @@ png_destroy_write_struct(png_structpp png_ptr_ptr, png_infopp info_ptr_ptr) if (info_ptr != NULL) { +#ifdef PNG_WRITE_tEXt_SUPPORTED + png_free(png_ptr, info_ptr->text); +#endif png_destroy_struct((png_voidp)info_ptr); *info_ptr_ptr = (png_infop)NULL; } @@ -561,6 +599,9 @@ png_write_destroy(png_structp png_ptr) png_free(png_ptr, png_ptr->up_row); png_free(png_ptr, png_ptr->avg_row); png_free(png_ptr, png_ptr->paeth_row); +#if defined(PNG_TIME_RFC1152_SUPPORTED) + png_free(png_ptr, png_ptr->time_buffer); +#endif /* PNG_TIME_RFC1152_SUPPORTED */ #if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED) png_free(png_ptr, png_ptr->prev_filters); png_free(png_ptr, png_ptr->filter_weights); @@ -683,7 +724,8 @@ png_set_filter(png_structp png_ptr, int method, int filters) * differences metric is relatively fast and effective, there is some * question as to whether it can be improved upon by trying to keep the * filtered data going to zlib more consistent, hopefully resulting in - * better compression. */ + * better compression. + */ #if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED) /* GRR 970116 */ void png_set_filter_heuristics(png_structp png_ptr, int heuristic_method, diff --git a/pngwtran.c b/pngwtran.c index 99d32a442..078b9f86d 100644 --- a/pngwtran.c +++ b/pngwtran.c @@ -1,18 +1,19 @@ /* pngwtran.c - transforms the data in a row for PNG writers - - libpng 1.0 beta 6 - version 0.96 - For conditions of distribution and use, see copyright notice in png.h - Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. - Copyright (c) 1996, 1997 Andreas Dilger - May 12, 1997 - */ + * + * libpng 1.00.97 + * For conditions of distribution and use, see copyright notice in png.h + * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. + * Copyright (c) 1996, 1997 Andreas Dilger + * May 28, 1997 + */ #define PNG_INTERNAL #include "png.h" -/* transform the data according to the users wishes. The order of - transformations is significant. */ +/* Transform the data according to the users wishes. The order of + * transformations is significant. + */ void png_do_write_transformations(png_structp png_ptr) { @@ -51,9 +52,10 @@ png_do_write_transformations(png_structp png_ptr) } #if defined(PNG_WRITE_PACK_SUPPORTED) -/* pack pixels into bytes. Pass the true bit depth in bit_depth. The - row_info bit depth should be 8 (one pixel per byte). The channels - should be 1 (this only happens on grayscale and paletted images) */ +/* Pack pixels into bytes. Pass the true bit depth in bit_depth. The + * row_info bit depth should be 8 (one pixel per byte). The channels + * should be 1 (this only happens on grayscale and paletted images). + */ void png_do_pack(png_row_infop row_info, png_bytep row, png_uint_32 bit_depth) { @@ -169,12 +171,13 @@ png_do_pack(png_row_infop row_info, png_bytep row, png_uint_32 bit_depth) #endif #if defined(PNG_WRITE_SHIFT_SUPPORTED) -/* shift pixel values to take advantage of whole range. Pass the - true number of bits in bit_depth. The row should be packed - according to row_info->bit_depth. Thus, if you had a row of - bit depth 4, but the pixels only had values from 0 to 7, you - would pass 3 as bit_depth, and this routine would translate the - data to 0 to 15. */ +/* Shift pixel values to take advantage of whole range. Pass the + * true number of bits in bit_depth. The row should be packed + * according to row_info->bit_depth. Thus, if you had a row of + * bit depth 4, but the pixels only had values from 0 to 7, you + * would pass 3 as bit_depth, and this routine would translate the + * data to 0 to 15. + */ void png_do_shift(png_row_infop row_info, png_bytep row, png_color_8p bit_depth) { @@ -252,7 +255,7 @@ png_do_shift(png_row_infop row_info, png_bytep row, png_color_8p bit_depth) for (bp = row, i = 0; i < row_info->width; i++) { - int c; + png_uint_32 c; for (c = 0; c < channels; c++, bp++) { @@ -278,7 +281,7 @@ png_do_shift(png_row_infop row_info, png_bytep row, png_color_8p bit_depth) for (bp = row, i = 0; i < row_info->width * row_info->channels; i++) { - int c; + png_uint_32 c; for (c = 0; c < channels; c++, bp += 2) { diff --git a/pngwutil.c b/pngwutil.c index 5aec80ce8..bad95a912 100644 --- a/pngwutil.c +++ b/pngwutil.c @@ -1,12 +1,12 @@ /* pngwutil.c - utilities to write a PNG file - - libpng 1.0 beta 6 - version 0.96 - For conditions of distribution and use, see copyright notice in png.h - Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. - Copyright (c) 1996, 1997 Andreas Dilger - May 12, 1997 - */ + * + * libpng 1.00.97 + * For conditions of distribution and use, see copyright notice in png.h + * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. + * Copyright (c) 1996, 1997 Andreas Dilger + * May 28, 1997 + */ #define PNG_INTERNAL #include "png.h" @@ -26,8 +26,9 @@ png_save_uint_32(png_bytep buf, png_uint_32 i) #if defined(PNG_WRITE_pCAL_SUPPORTED) /* The png_save_int_32 function assumes integers are stored in two's - complement format. If this isn't the case, then this routine needs to - be modified to write data in two's complement format. */ + * complement format. If this isn't the case, then this routine needs to + * be modified to write data in two's complement format. + */ void png_save_int_32(png_bytep buf, png_int_32 i) { @@ -38,22 +39,26 @@ png_save_int_32(png_bytep buf, png_int_32 i) } #endif -/* Place a 16-bit number into a buffer in PNG byte order. */ +/* Place a 16-bit number into a buffer in PNG byte order. + * The parameter is declared unsigned int, not png_uint_16, + * just to avoid potential problems on pre-ANSI C compilers. + */ void -png_save_uint_16(png_bytep buf, png_uint_16 i) +png_save_uint_16(png_bytep buf, unsigned int i) { buf[0] = (png_byte)((i >> 8) & 0xff); buf[1] = (png_byte)(i & 0xff); } /* Write a PNG chunk all at once. The type is an array of ASCII characters - representing the chunk name. The array must be at least 4 bytes in - length, and does not need to be null terminated. To be safe, pass the - pre-defined chunk names here, and if you need a new one, define it - where the others are defined. The length is the length of the data. - All the data must be present. If that is not possible, use the - png_write_chunk_start(), png_write_chunk_data(), and png_write_chunk_end() - functions instead. */ + * representing the chunk name. The array must be at least 4 bytes in + * length, and does not need to be null terminated. To be safe, pass the + * pre-defined chunk names here, and if you need a new one, define it + * where the others are defined. The length is the length of the data. + * All the data must be present. If that is not possible, use the + * png_write_chunk_start(), png_write_chunk_data(), and png_write_chunk_end() + * functions instead. + */ void png_write_chunk(png_structp png_ptr, png_bytep chunk_name, png_bytep data, png_size_t length) @@ -64,8 +69,9 @@ png_write_chunk(png_structp png_ptr, png_bytep chunk_name, } /* Write the start of a PNG chunk. The type is the chunk type. - The total_length is the sum of the lengths of all the data you will be - passing in png_write_chunk_data() */ + * The total_length is the sum of the lengths of all the data you will be + * passing in png_write_chunk_data(). + */ void png_write_chunk_start(png_structp png_ptr, png_bytep chunk_name, png_uint_32 length) @@ -85,9 +91,10 @@ png_write_chunk_start(png_structp png_ptr, png_bytep chunk_name, } /* Write the data of a PNG chunk started with png_write_chunk_start(). - Note that multiple calls to this function are allowed, and that the - sum of the lengths from these calls *must* add up to the total_length - given to png_write_chunk_start(). */ + * Note that multiple calls to this function are allowed, and that the + * sum of the lengths from these calls *must* add up to the total_length + * given to png_write_chunk_start(). + */ void png_write_chunk_data(png_structp png_ptr, png_bytep data, png_size_t length) { @@ -106,11 +113,7 @@ png_write_chunk_end(png_structp png_ptr) png_byte buf[4]; /* write the crc */ -#ifdef PNG_USE_OWN_CRC - png_save_uint_32(buf, ~png_ptr->crc); -#else png_save_uint_32(buf, png_ptr->crc); -#endif png_write_data(png_ptr, buf, (png_size_t)4); } @@ -119,7 +122,8 @@ png_write_chunk_end(png_structp png_ptr) * the magic bytes of the signature, or more likely, the PNG stream is * being embedded into another stream and doesn't need its own signature, * we should call png_set_sig_bytes() to tell libpng how many of the - * bytes have already been written. */ + * bytes have already been written. + */ void png_write_sig(png_structp png_ptr) { @@ -129,8 +133,9 @@ png_write_sig(png_structp png_ptr) } /* Write the IHDR chunk, and update the png_struct with the necessary - information. Note that the rest of this code depends upon this - information being correct. */ + * information. Note that the rest of this code depends upon this + * information being correct. + */ void png_write_IHDR(png_structp png_ptr, png_uint_32 width, png_uint_32 height, int bit_depth, int color_type, int compression_type, int filter_type, @@ -264,8 +269,9 @@ png_write_IHDR(png_structp png_ptr, png_uint_32 width, png_uint_32 height, } /* write the palette. We are careful not to trust png_color to be in the - correct order for PNG, so people can redefine it to any convient - structure. */ + * correct order for PNG, so people can redefine it to any convient + * structure. + */ void png_write_PLTE(png_structp png_ptr, png_colorp palette, png_uint_32 num_pal) { @@ -336,6 +342,22 @@ png_write_gAMA(png_structp png_ptr, double file_gamma) } #endif +#if defined(PNG_WRITE_sRGB_SUPPORTED) +/* write a sRGB chunk */ +void +png_write_sRGB(png_structp png_ptr, png_byte srgb_intent) +{ + png_byte buf[1]; + + png_debug(1, "in png_write_sRGB\n"); + if(srgb_intent > 3) + png_warning(png_ptr, + "Invalid sRGB rendering intent specified"); + buf[0]=srgb_intent; + png_write_chunk(png_ptr, png_sRGB, buf, (png_size_t)1); +} +#endif + #if defined(PNG_WRITE_sBIT_SUPPORTED) /* write the sBIT chunk */ void @@ -560,11 +582,10 @@ png_write_hIST(png_structp png_ptr, png_uint_16p hist, png_uint_32 num_hist) * static keywords without having to have duplicate copies of the strings. */ png_size_t -png_check_keyword(png_structp png_ptr, png_charp key, png_bytepp new_key) +png_check_keyword(png_structp png_ptr, png_charp key, png_charpp new_key) { png_size_t key_len; - png_charp kp; - png_bytep dp; + png_charp kp, dp; int kflag; png_debug(1, "in png_check_keyword\n"); @@ -581,12 +602,12 @@ png_check_keyword(png_structp png_ptr, png_charp key, png_bytepp new_key) png_debug1(2, "Keyword to be checked is '%s'\n", key); - *new_key = (png_bytep)png_malloc(png_ptr, key_len + 1); + *new_key = (png_charp)png_malloc(png_ptr, key_len + 1); /* Replace non-printing characters with a blank and print a warning */ for (kp = key, dp = *new_key; *kp != '\0'; kp++, dp++) { - if (*kp < 0x20 || ((png_byte)*kp > 0x7E && (png_byte)*kp < 0xA1)) + if (*kp < 0x20 || (*kp > 0x7E && *kp < 0xA1)) { char msg[40]; @@ -688,7 +709,7 @@ png_write_tEXt(png_structp png_ptr, png_charp key, png_charp text, png_size_t text_len) { png_size_t key_len; - png_bytep new_key; + png_charp new_key; png_debug(1, "in png_write_tEXt\n"); if (key == NULL || (key_len = png_check_keyword(png_ptr, key, &new_key))==0) @@ -705,7 +726,7 @@ png_write_tEXt(png_structp png_ptr, png_charp key, png_charp text, /* make sure we include the 0 after the key */ png_write_chunk_start(png_ptr, png_tEXt, (png_uint_32)key_len+text_len+1); - png_write_chunk_data(png_ptr, new_key, key_len + 1); + png_write_chunk_data(png_ptr, (png_bytep)new_key, key_len + 1); if (text_len) png_write_chunk_data(png_ptr, (png_bytep)text, text_len); @@ -722,7 +743,7 @@ png_write_zTXt(png_structp png_ptr, png_charp key, png_charp text, { png_size_t key_len; char buf[1]; - png_bytep new_key; + png_charp new_key; int i, ret; png_charpp output_ptr = NULL; /* array of pointers to output */ int num_output_ptr = 0; /* number of output pointers used */ @@ -945,7 +966,7 @@ png_write_pCAL(png_structp png_ptr, png_charp purpose, png_int_32 X0, png_size_t purpose_len, units_len, total_len; png_uint_32p params_len; png_byte buf[10]; - png_bytep new_purpose; + png_charp new_purpose; int i; png_debug1(1, "in png_write_pCAL (%d parameters)\n", nparams); @@ -971,7 +992,7 @@ png_write_pCAL(png_structp png_ptr, png_charp purpose, png_int_32 X0, png_debug1(3, "pCAL total length = %d\n", total_len); png_write_chunk_start(png_ptr, png_pCAL, total_len); - png_write_chunk_data(png_ptr, new_purpose, purpose_len); + png_write_chunk_data(png_ptr, (png_bytep)new_purpose, purpose_len); png_save_int_32(buf, X0); png_save_int_32(buf + 4, X1); buf[8] = (png_byte)type; @@ -1013,8 +1034,9 @@ png_write_pHYs(png_structp png_ptr, png_uint_32 x_pixels_per_unit, #endif #if defined(PNG_WRITE_tIME_SUPPORTED) -/* write the tIME chunk. Use either png_convert_from_struct_tm() - or png_convert_from_time_t(), or fill in the structure yourself */ +/* Write the tIME chunk. Use either png_convert_from_struct_tm() + * or png_convert_from_time_t(), or fill in the structure yourself. + */ void png_write_tIME(png_structp png_ptr, png_timep mod_time) { @@ -1206,14 +1228,13 @@ png_write_finish_row(png_structp png_ptr) } #if defined(PNG_WRITE_INTERLACING_SUPPORTED) -/* pick out the correct pixels for the interlace pass. - - The basic idea here is to go through the row with a source - pointer and a destination pointer (sp and dp), and copy the - correct pixels for the pass. As the row gets compacted, - sp will always be >= dp, so we should never overwrite anything. - See the default: case for the easiest code to understand. - */ +/* Pick out the correct pixels for the interlace pass. + * The basic idea here is to go through the row with a source + * pointer and a destination pointer (sp and dp), and copy the + * correct pixels for the pass. As the row gets compacted, + * sp will always be >= dp, so we should never overwrite anything. + * See the default: case for the easiest code to understand. + */ void png_do_write_interlace(png_row_infop row_info, png_bytep row, int pass) { @@ -1366,7 +1387,8 @@ png_do_write_interlace(png_row_infop row_info, png_bytep row, int pass) /* This filters the row, chooses which filter to use, if it has not already * been specified by the application, and then writes the row out with the - * chosen filter. */ + * chosen filter. + */ #define PNG_MAXSUM (~0x0UL >> 1) #define PNG_HISHIFT 10 #define PNG_LOMASK 0xffffL |