diff options
Diffstat (limited to 'Build/source/libs/libpng/libpng-1.6.17/contrib/libtests/pngvalid.c')
-rw-r--r-- | Build/source/libs/libpng/libpng-1.6.17/contrib/libtests/pngvalid.c | 11238 |
1 files changed, 0 insertions, 11238 deletions
diff --git a/Build/source/libs/libpng/libpng-1.6.17/contrib/libtests/pngvalid.c b/Build/source/libs/libpng/libpng-1.6.17/contrib/libtests/pngvalid.c deleted file mode 100644 index 79de125da11..00000000000 --- a/Build/source/libs/libpng/libpng-1.6.17/contrib/libtests/pngvalid.c +++ /dev/null @@ -1,11238 +0,0 @@ - -/* pngvalid.c - validate libpng by constructing then reading png files. - * - * Last changed in libpng 1.6.17 [March 26, 2015] - * Copyright (c) 2014-2015 Glenn Randers-Pehrson - * Written by John Cunningham Bowler - * - * This code is released under the libpng license. - * For conditions of distribution and use, see the disclaimer - * and license in png.h - * - * NOTES: - * This is a C program that is intended to be linked against libpng. It - * generates bitmaps internally, stores them as PNG files (using the - * sequential write code) then reads them back (using the sequential - * read code) and validates that the result has the correct data. - * - * The program can be modified and extended to test the correctness of - * transformations performed by libpng. - */ - -#define _POSIX_SOURCE 1 -#define _ISOC99_SOURCE 1 /* For floating point */ -#define _GNU_SOURCE 1 /* For the floating point exception extension */ - -#include <signal.h> -#include <stdio.h> - -#if defined(HAVE_CONFIG_H) && !defined(PNG_NO_CONFIG_H) -# include <config.h> -#endif - -#ifdef HAVE_FEENABLEEXCEPT /* from config.h, if included */ -# include <fenv.h> -#endif - -#ifndef FE_DIVBYZERO -# define FE_DIVBYZERO 0 -#endif -#ifndef FE_INVALID -# define FE_INVALID 0 -#endif -#ifndef FE_OVERFLOW -# define FE_OVERFLOW 0 -#endif - -/* Define the following to use this test against your installed libpng, rather - * than the one being built here: - */ -#ifdef PNG_FREESTANDING_TESTS -# include <png.h> -#else -# include "../../png.h" -#endif - -#ifdef PNG_ZLIB_HEADER -# include PNG_ZLIB_HEADER -#else -# include <zlib.h> /* For crc32 */ -#endif - -/* 1.6.1 added support for the configure test harness, which uses 77 to indicate - * a skipped test, in earlier versions we need to succeed on a skipped test, so: - */ -#if PNG_LIBPNG_VER < 10601 -# define SKIP 0 -#else -# define SKIP 77 -#endif - -/* pngvalid requires write support and one of the fixed or floating point APIs. - */ -#if defined(PNG_WRITE_SUPPORTED) &&\ - (defined(PNG_FIXED_POINT_SUPPORTED) || defined(PNG_FLOATING_POINT_SUPPORTED)) - -#if PNG_LIBPNG_VER < 10500 -/* This deliberately lacks the PNG_CONST. */ -typedef png_byte *png_const_bytep; - -/* This is copied from 1.5.1 png.h: */ -#define PNG_INTERLACE_ADAM7_PASSES 7 -#define PNG_PASS_START_ROW(pass) (((1U&~(pass))<<(3-((pass)>>1)))&7) -#define PNG_PASS_START_COL(pass) (((1U& (pass))<<(3-(((pass)+1)>>1)))&7) -#define PNG_PASS_ROW_SHIFT(pass) ((pass)>2?(8-(pass))>>1:3) -#define PNG_PASS_COL_SHIFT(pass) ((pass)>1?(7-(pass))>>1:3) -#define PNG_PASS_ROWS(height, pass) (((height)+(((1<<PNG_PASS_ROW_SHIFT(pass))\ - -1)-PNG_PASS_START_ROW(pass)))>>PNG_PASS_ROW_SHIFT(pass)) -#define PNG_PASS_COLS(width, pass) (((width)+(((1<<PNG_PASS_COL_SHIFT(pass))\ - -1)-PNG_PASS_START_COL(pass)))>>PNG_PASS_COL_SHIFT(pass)) -#define PNG_ROW_FROM_PASS_ROW(yIn, pass) \ - (((yIn)<<PNG_PASS_ROW_SHIFT(pass))+PNG_PASS_START_ROW(pass)) -#define PNG_COL_FROM_PASS_COL(xIn, pass) \ - (((xIn)<<PNG_PASS_COL_SHIFT(pass))+PNG_PASS_START_COL(pass)) -#define PNG_PASS_MASK(pass,off) ( \ - ((0x110145AFU>>(((7-(off))-(pass))<<2)) & 0xFU) | \ - ((0x01145AF0U>>(((7-(off))-(pass))<<2)) & 0xF0U)) -#define PNG_ROW_IN_INTERLACE_PASS(y, pass) \ - ((PNG_PASS_MASK(pass,0) >> ((y)&7)) & 1) -#define PNG_COL_IN_INTERLACE_PASS(x, pass) \ - ((PNG_PASS_MASK(pass,1) >> ((x)&7)) & 1) - -/* These are needed too for the default build: */ -#define PNG_WRITE_16BIT_SUPPORTED -#define PNG_READ_16BIT_SUPPORTED - -/* This comes from pnglibconf.h afer 1.5: */ -#define PNG_FP_1 100000 -#define PNG_GAMMA_THRESHOLD_FIXED\ - ((png_fixed_point)(PNG_GAMMA_THRESHOLD * PNG_FP_1)) -#endif - -#if PNG_LIBPNG_VER < 10600 - /* 1.6.0 constifies many APIs, the following exists to allow pngvalid to be - * compiled against earlier versions. - */ -# define png_const_structp png_structp -#endif - -#include <float.h> /* For floating point constants */ -#include <stdlib.h> /* For malloc */ -#include <string.h> /* For memcpy, memset */ -#include <math.h> /* For floor */ - -/* Unused formal parameter errors are removed using the following macro which is - * expected to have no bad effects on performance. - */ -#ifndef UNUSED -# if defined(__GNUC__) || defined(_MSC_VER) -# define UNUSED(param) (void)param; -# else -# define UNUSED(param) -# endif -#endif - -/***************************** EXCEPTION HANDLING *****************************/ -#ifdef PNG_FREESTANDING_TESTS -# include <cexcept.h> -#else -# include "../visupng/cexcept.h" -#endif - -#ifdef __cplusplus -# define this not_the_cpp_this -# define new not_the_cpp_new -# define voidcast(type, value) static_cast<type>(value) -#else -# define voidcast(type, value) (value) -#endif /* __cplusplus */ - -struct png_store; -define_exception_type(struct png_store*); - -/* The following are macros to reduce typing everywhere where the well known - * name 'the_exception_context' must be defined. - */ -#define anon_context(ps) struct exception_context *the_exception_context = \ - &(ps)->exception_context -#define context(ps,fault) anon_context(ps); png_store *fault - -/* This macro returns the number of elements in an array as an (unsigned int), - * it is necessary to avoid the inability of certain versions of GCC to use - * the value of a compile-time constant when performing range checks. It must - * be passed an array name. - */ -#define ARRAY_SIZE(a) ((unsigned int)((sizeof (a))/(sizeof (a)[0]))) - -/******************************* UTILITIES ************************************/ -/* Error handling is particularly problematic in production code - error - * handlers often themselves have bugs which lead to programs that detect - * minor errors crashing. The following functions deal with one very - * common class of errors in error handlers - attempting to format error or - * warning messages into buffers that are too small. - */ -static size_t safecat(char *buffer, size_t bufsize, size_t pos, - PNG_CONST char *cat) -{ - while (pos < bufsize && cat != NULL && *cat != 0) - buffer[pos++] = *cat++; - - if (pos >= bufsize) - pos = bufsize-1; - - buffer[pos] = 0; - return pos; -} - -static size_t safecatn(char *buffer, size_t bufsize, size_t pos, int n) -{ - char number[64]; - sprintf(number, "%d", n); - return safecat(buffer, bufsize, pos, number); -} - -#ifdef PNG_READ_TRANSFORMS_SUPPORTED -static size_t safecatd(char *buffer, size_t bufsize, size_t pos, double d, - int precision) -{ - char number[64]; - sprintf(number, "%.*f", precision, d); - return safecat(buffer, bufsize, pos, number); -} -#endif - -static PNG_CONST char invalid[] = "invalid"; -static PNG_CONST char sep[] = ": "; - -static PNG_CONST char *colour_types[8] = -{ - "grayscale", invalid, "truecolour", "indexed-colour", - "grayscale with alpha", invalid, "truecolour with alpha", invalid -}; - -#ifdef PNG_READ_SUPPORTED -/* Convert a double precision value to fixed point. */ -static png_fixed_point -fix(double d) -{ - d = floor(d * PNG_FP_1 + .5); - return (png_fixed_point)d; -} -#endif /* PNG_READ_SUPPORTED */ - -/* Generate random bytes. This uses a boring repeatable algorithm and it - * is implemented here so that it gives the same set of numbers on every - * architecture. It's a linear congruential generator (Knuth or Sedgewick - * "Algorithms") but it comes from the 'feedback taps' table in Horowitz and - * Hill, "The Art of Electronics" (Pseudo-Random Bit Sequences and Noise - * Generation.) - */ -static void -make_random_bytes(png_uint_32* seed, void* pv, size_t size) -{ - png_uint_32 u0 = seed[0], u1 = seed[1]; - png_bytep bytes = voidcast(png_bytep, pv); - - /* There are thirty three bits, the next bit in the sequence is bit-33 XOR - * bit-20. The top 1 bit is in u1, the bottom 32 are in u0. - */ - size_t i; - for (i=0; i<size; ++i) - { - /* First generate 8 new bits then shift them in at the end. */ - png_uint_32 u = ((u0 >> (20-8)) ^ ((u1 << 7) | (u0 >> (32-7)))) & 0xff; - u1 <<= 8; - u1 |= u0 >> 24; - u0 <<= 8; - u0 |= u; - *bytes++ = (png_byte)u; - } - - seed[0] = u0; - seed[1] = u1; -} - -static void -make_four_random_bytes(png_uint_32* seed, png_bytep bytes) -{ - make_random_bytes(seed, bytes, 4); -} - -#ifdef PNG_READ_SUPPORTED -static void -randomize(void *pv, size_t size) -{ - static png_uint_32 random_seed[2] = {0x56789abc, 0xd}; - make_random_bytes(random_seed, pv, size); -} - -#define RANDOMIZE(this) randomize(&(this), sizeof (this)) - -static unsigned int -random_mod(unsigned int max) -{ - unsigned int x; - - RANDOMIZE(x); - - return x % max; /* 0 .. max-1 */ -} - -#if (defined PNG_READ_RGB_TO_GRAY_SUPPORTED) ||\ - (defined PNG_READ_FILLER_SUPPORTED) -static int -random_choice(void) -{ - unsigned char x; - - RANDOMIZE(x); - - return x & 1; -} -#endif -#endif /* PNG_READ_SUPPORTED */ - -/* A numeric ID based on PNG file characteristics. The 'do_interlace' field - * simply records whether pngvalid did the interlace itself or whether it - * was done by libpng. Width and height must be less than 256. 'palette' is an - * index of the palette to use for formats with a palette (0 otherwise.) - */ -#define FILEID(col, depth, palette, interlace, width, height, do_interlace) \ - ((png_uint_32)((col) + ((depth)<<3) + ((palette)<<8) + ((interlace)<<13) + \ - (((do_interlace)!=0)<<15) + ((width)<<16) + ((height)<<24))) - -#define COL_FROM_ID(id) ((png_byte)((id)& 0x7U)) -#define DEPTH_FROM_ID(id) ((png_byte)(((id) >> 3) & 0x1fU)) -#define PALETTE_FROM_ID(id) (((id) >> 8) & 0x1f) -#define INTERLACE_FROM_ID(id) ((png_byte)(((id) >> 13) & 0x3)) -#define DO_INTERLACE_FROM_ID(id) ((int)(((id)>>15) & 1)) -#define WIDTH_FROM_ID(id) (((id)>>16) & 0xff) -#define HEIGHT_FROM_ID(id) (((id)>>24) & 0xff) - -/* Utility to construct a standard name for a standard image. */ -static size_t -standard_name(char *buffer, size_t bufsize, size_t pos, png_byte colour_type, - int bit_depth, unsigned int npalette, int interlace_type, - png_uint_32 w, png_uint_32 h, int do_interlace) -{ - pos = safecat(buffer, bufsize, pos, colour_types[colour_type]); - if (npalette > 0) - { - pos = safecat(buffer, bufsize, pos, "["); - pos = safecatn(buffer, bufsize, pos, npalette); - pos = safecat(buffer, bufsize, pos, "]"); - } - pos = safecat(buffer, bufsize, pos, " "); - pos = safecatn(buffer, bufsize, pos, bit_depth); - pos = safecat(buffer, bufsize, pos, " bit"); - - if (interlace_type != PNG_INTERLACE_NONE) - { - pos = safecat(buffer, bufsize, pos, " interlaced"); - if (do_interlace) - pos = safecat(buffer, bufsize, pos, "(pngvalid)"); - else - pos = safecat(buffer, bufsize, pos, "(libpng)"); - } - - if (w > 0 || h > 0) - { - pos = safecat(buffer, bufsize, pos, " "); - pos = safecatn(buffer, bufsize, pos, w); - pos = safecat(buffer, bufsize, pos, "x"); - pos = safecatn(buffer, bufsize, pos, h); - } - - return pos; -} - -static size_t -standard_name_from_id(char *buffer, size_t bufsize, size_t pos, png_uint_32 id) -{ - return standard_name(buffer, bufsize, pos, COL_FROM_ID(id), - DEPTH_FROM_ID(id), PALETTE_FROM_ID(id), INTERLACE_FROM_ID(id), - WIDTH_FROM_ID(id), HEIGHT_FROM_ID(id), DO_INTERLACE_FROM_ID(id)); -} - -/* Convenience API and defines to list valid formats. Note that 16 bit read and - * write support is required to do 16 bit read tests (we must be able to make a - * 16 bit image to test!) - */ -#ifdef PNG_WRITE_16BIT_SUPPORTED -# define WRITE_BDHI 4 -# ifdef PNG_READ_16BIT_SUPPORTED -# define READ_BDHI 4 -# define DO_16BIT -# endif -#else -# define WRITE_BDHI 3 -#endif -#ifndef DO_16BIT -# define READ_BDHI 3 -#endif - -/* The following defines the number of different palettes to generate for - * each log bit depth of a colour type 3 standard image. - */ -#define PALETTE_COUNT(bit_depth) ((bit_depth) > 4 ? 1U : 16U) - -static int -next_format(png_bytep colour_type, png_bytep bit_depth, - unsigned int* palette_number, int no_low_depth_gray) -{ - if (*bit_depth == 0) - { - *colour_type = 0; - if (no_low_depth_gray) - *bit_depth = 8; - else - *bit_depth = 1; - *palette_number = 0; - return 1; - } - - if (*colour_type == 3) - { - /* Add multiple palettes for colour type 3. */ - if (++*palette_number < PALETTE_COUNT(*bit_depth)) - return 1; - - *palette_number = 0; - } - - *bit_depth = (png_byte)(*bit_depth << 1); - - /* Palette images are restricted to 8 bit depth */ - if (*bit_depth <= 8 -#ifdef DO_16BIT - || (*colour_type != 3 && *bit_depth <= 16) -#endif - ) - return 1; - - /* Move to the next color type, or return 0 at the end. */ - switch (*colour_type) - { - case 0: - *colour_type = 2; - *bit_depth = 8; - return 1; - - case 2: - *colour_type = 3; - *bit_depth = 1; - return 1; - - case 3: - *colour_type = 4; - *bit_depth = 8; - return 1; - - case 4: - *colour_type = 6; - *bit_depth = 8; - return 1; - - default: - return 0; - } -} - -#ifdef PNG_READ_TRANSFORMS_SUPPORTED -static unsigned int -sample(png_const_bytep row, png_byte colour_type, png_byte bit_depth, - png_uint_32 x, unsigned int sample_index, int swap16, int littleendian) -{ - png_uint_32 bit_index, result; - - /* Find a sample index for the desired sample: */ - x *= bit_depth; - bit_index = x; - - if ((colour_type & 1) == 0) /* !palette */ - { - if (colour_type & 2) - bit_index *= 3; - - if (colour_type & 4) - bit_index += x; /* Alpha channel */ - - /* Multiple channels; select one: */ - if (colour_type & (2+4)) - bit_index += sample_index * bit_depth; - } - - /* Return the sample from the row as an integer. */ - row += bit_index >> 3; - result = *row; - - if (bit_depth == 8) - return result; - - else if (bit_depth > 8) - { - if (swap16) - return (*++row << 8) + result; - else - return (result << 8) + *++row; - } - - /* Less than 8 bits per sample. By default PNG has the big end of - * the egg on the left of the screen, but if littleendian is set - * then the big end is on the right. - */ - bit_index &= 7; - - if (!littleendian) - bit_index = 8-bit_index-bit_depth; - - return (result >> bit_index) & ((1U<<bit_depth)-1); -} -#endif /* PNG_READ_TRANSFORMS_SUPPORTED */ - -/* Copy a single pixel, of a given size, from one buffer to another - - * while this is basically bit addressed there is an implicit assumption - * that pixels 8 or more bits in size are byte aligned and that pixels - * do not otherwise cross byte boundaries. (This is, so far as I know, - * universally true in bitmap computer graphics. [JCB 20101212]) - * - * NOTE: The to and from buffers may be the same. - */ -static void -pixel_copy(png_bytep toBuffer, png_uint_32 toIndex, - png_const_bytep fromBuffer, png_uint_32 fromIndex, unsigned int pixelSize) -{ - /* Assume we can multiply by 'size' without overflow because we are - * just working in a single buffer. - */ - toIndex *= pixelSize; - fromIndex *= pixelSize; - if (pixelSize < 8) /* Sub-byte */ - { - /* Mask to select the location of the copied pixel: */ - unsigned int destMask = ((1U<<pixelSize)-1) << (8-pixelSize-(toIndex&7)); - /* The following read the entire pixels and clears the extra: */ - unsigned int destByte = toBuffer[toIndex >> 3] & ~destMask; - unsigned int sourceByte = fromBuffer[fromIndex >> 3]; - - /* Don't rely on << or >> supporting '0' here, just in case: */ - fromIndex &= 7; - if (fromIndex > 0) sourceByte <<= fromIndex; - if ((toIndex & 7) > 0) sourceByte >>= toIndex & 7; - - toBuffer[toIndex >> 3] = (png_byte)(destByte | (sourceByte & destMask)); - } - else /* One or more bytes */ - memmove(toBuffer+(toIndex>>3), fromBuffer+(fromIndex>>3), pixelSize>>3); -} - -#ifdef PNG_READ_SUPPORTED -/* Copy a complete row of pixels, taking into account potential partial - * bytes at the end. - */ -static void -row_copy(png_bytep toBuffer, png_const_bytep fromBuffer, unsigned int bitWidth) -{ - memcpy(toBuffer, fromBuffer, bitWidth >> 3); - - if ((bitWidth & 7) != 0) - { - unsigned int mask; - - toBuffer += bitWidth >> 3; - fromBuffer += bitWidth >> 3; - /* The remaining bits are in the top of the byte, the mask is the bits to - * retain. - */ - mask = 0xff >> (bitWidth & 7); - *toBuffer = (png_byte)((*toBuffer & mask) | (*fromBuffer & ~mask)); - } -} - -/* Compare pixels - they are assumed to start at the first byte in the - * given buffers. - */ -static int -pixel_cmp(png_const_bytep pa, png_const_bytep pb, png_uint_32 bit_width) -{ -#if PNG_LIBPNG_VER < 10506 - if (memcmp(pa, pb, bit_width>>3) == 0) - { - png_uint_32 p; - - if ((bit_width & 7) == 0) return 0; - - /* Ok, any differences? */ - p = pa[bit_width >> 3]; - p ^= pb[bit_width >> 3]; - - if (p == 0) return 0; - - /* There are, but they may not be significant, remove the bits - * after the end (the low order bits in PNG.) - */ - bit_width &= 7; - p >>= 8-bit_width; - - if (p == 0) return 0; - } -#else - /* From libpng-1.5.6 the overwrite should be fixed, so compare the trailing - * bits too: - */ - if (memcmp(pa, pb, (bit_width+7)>>3) == 0) - return 0; -#endif - - /* Return the index of the changed byte. */ - { - png_uint_32 where = 0; - - while (pa[where] == pb[where]) ++where; - return 1+where; - } -} -#endif /* PNG_READ_SUPPORTED */ - -/*************************** BASIC PNG FILE WRITING ***************************/ -/* A png_store takes data from the sequential writer or provides data - * to the sequential reader. It can also store the result of a PNG - * write for later retrieval. - */ -#define STORE_BUFFER_SIZE 500 /* arbitrary */ -typedef struct png_store_buffer -{ - struct png_store_buffer* prev; /* NOTE: stored in reverse order */ - png_byte buffer[STORE_BUFFER_SIZE]; -} png_store_buffer; - -#define FILE_NAME_SIZE 64 - -typedef struct store_palette_entry /* record of a single palette entry */ -{ - png_byte red; - png_byte green; - png_byte blue; - png_byte alpha; -} store_palette_entry, store_palette[256]; - -typedef struct png_store_file -{ - struct png_store_file* next; /* as many as you like... */ - char name[FILE_NAME_SIZE]; - png_uint_32 id; /* must be correct (see FILEID) */ - png_size_t datacount; /* In this (the last) buffer */ - png_store_buffer data; /* Last buffer in file */ - int npalette; /* Number of entries in palette */ - store_palette_entry* palette; /* May be NULL */ -} png_store_file; - -/* The following is a pool of memory allocated by a single libpng read or write - * operation. - */ -typedef struct store_pool -{ - struct png_store *store; /* Back pointer */ - struct store_memory *list; /* List of allocated memory */ - png_byte mark[4]; /* Before and after data */ - - /* Statistics for this run. */ - png_alloc_size_t max; /* Maximum single allocation */ - png_alloc_size_t current; /* Current allocation */ - png_alloc_size_t limit; /* Highest current allocation */ - png_alloc_size_t total; /* Total allocation */ - - /* Overall statistics (retained across successive runs). */ - png_alloc_size_t max_max; - png_alloc_size_t max_limit; - png_alloc_size_t max_total; -} store_pool; - -typedef struct png_store -{ - /* For cexcept.h exception handling - simply store one of these; - * the context is a self pointer but it may point to a different - * png_store (in fact it never does in this program.) - */ - struct exception_context - exception_context; - - unsigned int verbose :1; - unsigned int treat_warnings_as_errors :1; - unsigned int expect_error :1; - unsigned int expect_warning :1; - unsigned int saw_warning :1; - unsigned int speed :1; - unsigned int progressive :1; /* use progressive read */ - unsigned int validated :1; /* used as a temporary flag */ - int nerrors; - int nwarnings; - int noptions; /* number of options below: */ - struct { - unsigned char option; /* option number, 0..30 */ - unsigned char setting; /* setting (unset,invalid,on,off) */ - } options[16]; - char test[128]; /* Name of test */ - char error[256]; - - /* Read fields */ - png_structp pread; /* Used to read a saved file */ - png_infop piread; - png_store_file* current; /* Set when reading */ - png_store_buffer* next; /* Set when reading */ - png_size_t readpos; /* Position in *next */ - png_byte* image; /* Buffer for reading interlaced images */ - png_size_t cb_image; /* Size of this buffer */ - png_size_t cb_row; /* Row size of the image(s) */ - png_uint_32 image_h; /* Number of rows in a single image */ - store_pool read_memory_pool; - - /* Write fields */ - png_store_file* saved; - png_structp pwrite; /* Used when writing a new file */ - png_infop piwrite; - png_size_t writepos; /* Position in .new */ - char wname[FILE_NAME_SIZE]; - png_store_buffer new; /* The end of the new PNG file being written. */ - store_pool write_memory_pool; - store_palette_entry* palette; - int npalette; -} png_store; - -/* Initialization and cleanup */ -static void -store_pool_mark(png_bytep mark) -{ - static png_uint_32 store_seed[2] = { 0x12345678, 1}; - - make_four_random_bytes(store_seed, mark); -} - -#ifdef PNG_READ_SUPPORTED -/* Use this for random 32 bit values; this function makes sure the result is - * non-zero. - */ -static png_uint_32 -random_32(void) -{ - - for (;;) - { - png_byte mark[4]; - png_uint_32 result; - - store_pool_mark(mark); - result = png_get_uint_32(mark); - - if (result != 0) - return result; - } -} -#endif /* PNG_READ_SUPPORTED */ - -static void -store_pool_init(png_store *ps, store_pool *pool) -{ - memset(pool, 0, sizeof *pool); - - pool->store = ps; - pool->list = NULL; - pool->max = pool->current = pool->limit = pool->total = 0; - pool->max_max = pool->max_limit = pool->max_total = 0; - store_pool_mark(pool->mark); -} - -static void -store_init(png_store* ps) -{ - memset(ps, 0, sizeof *ps); - init_exception_context(&ps->exception_context); - store_pool_init(ps, &ps->read_memory_pool); - store_pool_init(ps, &ps->write_memory_pool); - ps->verbose = 0; - ps->treat_warnings_as_errors = 0; - ps->expect_error = 0; - ps->expect_warning = 0; - ps->saw_warning = 0; - ps->speed = 0; - ps->progressive = 0; - ps->validated = 0; - ps->nerrors = ps->nwarnings = 0; - ps->pread = NULL; - ps->piread = NULL; - ps->saved = ps->current = NULL; - ps->next = NULL; - ps->readpos = 0; - ps->image = NULL; - ps->cb_image = 0; - ps->cb_row = 0; - ps->image_h = 0; - ps->pwrite = NULL; - ps->piwrite = NULL; - ps->writepos = 0; - ps->new.prev = NULL; - ps->palette = NULL; - ps->npalette = 0; - ps->noptions = 0; -} - -static void -store_freebuffer(png_store_buffer* psb) -{ - if (psb->prev) - { - store_freebuffer(psb->prev); - free(psb->prev); - psb->prev = NULL; - } -} - -static void -store_freenew(png_store *ps) -{ - store_freebuffer(&ps->new); - ps->writepos = 0; - if (ps->palette != NULL) - { - free(ps->palette); - ps->palette = NULL; - ps->npalette = 0; - } -} - -static void -store_storenew(png_store *ps) -{ - png_store_buffer *pb; - - if (ps->writepos != STORE_BUFFER_SIZE) - png_error(ps->pwrite, "invalid store call"); - - pb = voidcast(png_store_buffer*, malloc(sizeof *pb)); - - if (pb == NULL) - png_error(ps->pwrite, "store new: OOM"); - - *pb = ps->new; - ps->new.prev = pb; - ps->writepos = 0; -} - -static void -store_freefile(png_store_file **ppf) -{ - if (*ppf != NULL) - { - store_freefile(&(*ppf)->next); - - store_freebuffer(&(*ppf)->data); - (*ppf)->datacount = 0; - if ((*ppf)->palette != NULL) - { - free((*ppf)->palette); - (*ppf)->palette = NULL; - (*ppf)->npalette = 0; - } - free(*ppf); - *ppf = NULL; - } -} - -/* Main interface to file storeage, after writing a new PNG file (see the API - * below) call store_storefile to store the result with the given name and id. - */ -static void -store_storefile(png_store *ps, png_uint_32 id) -{ - png_store_file *pf = voidcast(png_store_file*, malloc(sizeof *pf)); - if (pf == NULL) - png_error(ps->pwrite, "storefile: OOM"); - safecat(pf->name, sizeof pf->name, 0, ps->wname); - pf->id = id; - pf->data = ps->new; - pf->datacount = ps->writepos; - ps->new.prev = NULL; - ps->writepos = 0; - pf->palette = ps->palette; - pf->npalette = ps->npalette; - ps->palette = 0; - ps->npalette = 0; - - /* And save it. */ - pf->next = ps->saved; - ps->saved = pf; -} - -/* Generate an error message (in the given buffer) */ -static size_t -store_message(png_store *ps, png_const_structp pp, char *buffer, size_t bufsize, - size_t pos, PNG_CONST char *msg) -{ - if (pp != NULL && pp == ps->pread) - { - /* Reading a file */ - pos = safecat(buffer, bufsize, pos, "read: "); - - if (ps->current != NULL) - { - pos = safecat(buffer, bufsize, pos, ps->current->name); - pos = safecat(buffer, bufsize, pos, sep); - } - } - - else if (pp != NULL && pp == ps->pwrite) - { - /* Writing a file */ - pos = safecat(buffer, bufsize, pos, "write: "); - pos = safecat(buffer, bufsize, pos, ps->wname); - pos = safecat(buffer, bufsize, pos, sep); - } - - else - { - /* Neither reading nor writing (or a memory error in struct delete) */ - pos = safecat(buffer, bufsize, pos, "pngvalid: "); - } - - if (ps->test[0] != 0) - { - pos = safecat(buffer, bufsize, pos, ps->test); - pos = safecat(buffer, bufsize, pos, sep); - } - pos = safecat(buffer, bufsize, pos, msg); - return pos; -} - -/* Verbose output to the error stream: */ -static void -store_verbose(png_store *ps, png_const_structp pp, png_const_charp prefix, - png_const_charp message) -{ - char buffer[512]; - - if (prefix) - fputs(prefix, stderr); - - (void)store_message(ps, pp, buffer, sizeof buffer, 0, message); - fputs(buffer, stderr); - fputc('\n', stderr); -} - -/* Log an error or warning - the relevant count is always incremented. */ -static void -store_log(png_store* ps, png_const_structp pp, png_const_charp message, - int is_error) -{ - /* The warning is copied to the error buffer if there are no errors and it is - * the first warning. The error is copied to the error buffer if it is the - * first error (overwriting any prior warnings). - */ - if (is_error ? (ps->nerrors)++ == 0 : - (ps->nwarnings)++ == 0 && ps->nerrors == 0) - store_message(ps, pp, ps->error, sizeof ps->error, 0, message); - - if (ps->verbose) - store_verbose(ps, pp, is_error ? "error: " : "warning: ", message); -} - -#ifdef PNG_READ_SUPPORTED -/* Internal error function, called with a png_store but no libpng stuff. */ -static void -internal_error(png_store *ps, png_const_charp message) -{ - store_log(ps, NULL, message, 1 /* error */); - - /* And finally throw an exception. */ - { - struct exception_context *the_exception_context = &ps->exception_context; - Throw ps; - } -} -#endif /* PNG_READ_SUPPORTED */ - -/* Functions to use as PNG callbacks. */ -static void PNGCBAPI -store_error(png_structp ppIn, png_const_charp message) /* PNG_NORETURN */ -{ - png_const_structp pp = ppIn; - png_store *ps = voidcast(png_store*, png_get_error_ptr(pp)); - - if (!ps->expect_error) - store_log(ps, pp, message, 1 /* error */); - - /* And finally throw an exception. */ - { - struct exception_context *the_exception_context = &ps->exception_context; - Throw ps; - } -} - -static void PNGCBAPI -store_warning(png_structp ppIn, png_const_charp message) -{ - png_const_structp pp = ppIn; - png_store *ps = voidcast(png_store*, png_get_error_ptr(pp)); - - if (!ps->expect_warning) - store_log(ps, pp, message, 0 /* warning */); - else - ps->saw_warning = 1; -} - -/* These somewhat odd functions are used when reading an image to ensure that - * the buffer is big enough, the png_structp is for errors. - */ -/* Return a single row from the correct image. */ -static png_bytep -store_image_row(PNG_CONST png_store* ps, png_const_structp pp, int nImage, - png_uint_32 y) -{ - png_size_t coffset = (nImage * ps->image_h + y) * (ps->cb_row + 5) + 2; - - if (ps->image == NULL) - png_error(pp, "no allocated image"); - - if (coffset + ps->cb_row + 3 > ps->cb_image) - png_error(pp, "image too small"); - - return ps->image + coffset; -} - -static void -store_image_free(png_store *ps, png_const_structp pp) -{ - if (ps->image != NULL) - { - png_bytep image = ps->image; - - if (image[-1] != 0xed || image[ps->cb_image] != 0xfe) - { - if (pp != NULL) - png_error(pp, "png_store image overwrite (1)"); - else - store_log(ps, NULL, "png_store image overwrite (2)", 1); - } - - ps->image = NULL; - ps->cb_image = 0; - --image; - free(image); - } -} - -static void -store_ensure_image(png_store *ps, png_const_structp pp, int nImages, - png_size_t cbRow, png_uint_32 cRows) -{ - png_size_t cb = nImages * cRows * (cbRow + 5); - - if (ps->cb_image < cb) - { - png_bytep image; - - store_image_free(ps, pp); - - /* The buffer is deliberately mis-aligned. */ - image = voidcast(png_bytep, malloc(cb+2)); - if (image == NULL) - { - /* Called from the startup - ignore the error for the moment. */ - if (pp == NULL) - return; - - png_error(pp, "OOM allocating image buffer"); - } - - /* These magic tags are used to detect overwrites above. */ - ++image; - image[-1] = 0xed; - image[cb] = 0xfe; - - ps->image = image; - ps->cb_image = cb; - } - - /* We have an adequate sized image; lay out the rows. There are 2 bytes at - * the start and three at the end of each (this ensures that the row - * alignment starts out odd - 2+1 and changes for larger images on each row.) - */ - ps->cb_row = cbRow; - ps->image_h = cRows; - - /* For error checking, the whole buffer is set to 10110010 (0xb2 - 178). - * This deliberately doesn't match the bits in the size test image which are - * outside the image; these are set to 0xff (all 1). To make the row - * comparison work in the 'size' test case the size rows are pre-initialized - * to the same value prior to calling 'standard_row'. - */ - memset(ps->image, 178, cb); - - /* Then put in the marks. */ - while (--nImages >= 0) - { - png_uint_32 y; - - for (y=0; y<cRows; ++y) - { - png_bytep row = store_image_row(ps, pp, nImages, y); - - /* The markers: */ - row[-2] = 190; - row[-1] = 239; - row[cbRow] = 222; - row[cbRow+1] = 173; - row[cbRow+2] = 17; - } - } -} - -#ifdef PNG_READ_SUPPORTED -static void -store_image_check(PNG_CONST png_store* ps, png_const_structp pp, int iImage) -{ - png_const_bytep image = ps->image; - - if (image[-1] != 0xed || image[ps->cb_image] != 0xfe) - png_error(pp, "image overwrite"); - else - { - png_size_t cbRow = ps->cb_row; - png_uint_32 rows = ps->image_h; - - image += iImage * (cbRow+5) * ps->image_h; - - image += 2; /* skip image first row markers */ - - while (rows-- > 0) - { - if (image[-2] != 190 || image[-1] != 239) - png_error(pp, "row start overwritten"); - - if (image[cbRow] != 222 || image[cbRow+1] != 173 || - image[cbRow+2] != 17) - png_error(pp, "row end overwritten"); - - image += cbRow+5; - } - } -} -#endif /* PNG_READ_SUPPORTED */ - -static void PNGCBAPI -store_write(png_structp ppIn, png_bytep pb, png_size_t st) -{ - png_const_structp pp = ppIn; - png_store *ps = voidcast(png_store*, png_get_io_ptr(pp)); - - if (ps->pwrite != pp) - png_error(pp, "store state damaged"); - - while (st > 0) - { - size_t cb; - - if (ps->writepos >= STORE_BUFFER_SIZE) - store_storenew(ps); - - cb = st; - - if (cb > STORE_BUFFER_SIZE - ps->writepos) - cb = STORE_BUFFER_SIZE - ps->writepos; - - memcpy(ps->new.buffer + ps->writepos, pb, cb); - pb += cb; - st -= cb; - ps->writepos += cb; - } -} - -static void PNGCBAPI -store_flush(png_structp ppIn) -{ - UNUSED(ppIn) /*DOES NOTHING*/ -} - -#ifdef PNG_READ_SUPPORTED -static size_t -store_read_buffer_size(png_store *ps) -{ - /* Return the bytes available for read in the current buffer. */ - if (ps->next != &ps->current->data) - return STORE_BUFFER_SIZE; - - return ps->current->datacount; -} - -#ifdef PNG_READ_TRANSFORMS_SUPPORTED -/* Return total bytes available for read. */ -static size_t -store_read_buffer_avail(png_store *ps) -{ - if (ps->current != NULL && ps->next != NULL) - { - png_store_buffer *next = &ps->current->data; - size_t cbAvail = ps->current->datacount; - - while (next != ps->next && next != NULL) - { - next = next->prev; - cbAvail += STORE_BUFFER_SIZE; - } - - if (next != ps->next) - png_error(ps->pread, "buffer read error"); - - if (cbAvail > ps->readpos) - return cbAvail - ps->readpos; - } - - return 0; -} -#endif - -static int -store_read_buffer_next(png_store *ps) -{ - png_store_buffer *pbOld = ps->next; - png_store_buffer *pbNew = &ps->current->data; - if (pbOld != pbNew) - { - while (pbNew != NULL && pbNew->prev != pbOld) - pbNew = pbNew->prev; - - if (pbNew != NULL) - { - ps->next = pbNew; - ps->readpos = 0; - return 1; - } - - png_error(ps->pread, "buffer lost"); - } - - return 0; /* EOF or error */ -} - -/* Need separate implementation and callback to allow use of the same code - * during progressive read, where the io_ptr is set internally by libpng. - */ -static void -store_read_imp(png_store *ps, png_bytep pb, png_size_t st) -{ - if (ps->current == NULL || ps->next == NULL) - png_error(ps->pread, "store state damaged"); - - while (st > 0) - { - size_t cbAvail = store_read_buffer_size(ps) - ps->readpos; - - if (cbAvail > 0) - { - if (cbAvail > st) cbAvail = st; - memcpy(pb, ps->next->buffer + ps->readpos, cbAvail); - st -= cbAvail; - pb += cbAvail; - ps->readpos += cbAvail; - } - - else if (!store_read_buffer_next(ps)) - png_error(ps->pread, "read beyond end of file"); - } -} - -static void PNGCBAPI -store_read(png_structp ppIn, png_bytep pb, png_size_t st) -{ - png_const_structp pp = ppIn; - png_store *ps = voidcast(png_store*, png_get_io_ptr(pp)); - - if (ps == NULL || ps->pread != pp) - png_error(pp, "bad store read call"); - - store_read_imp(ps, pb, st); -} - -static void -store_progressive_read(png_store *ps, png_structp pp, png_infop pi) -{ - /* Notice that a call to store_read will cause this function to fail because - * readpos will be set. - */ - if (ps->pread != pp || ps->current == NULL || ps->next == NULL) - png_error(pp, "store state damaged (progressive)"); - - do - { - if (ps->readpos != 0) - png_error(pp, "store_read called during progressive read"); - - png_process_data(pp, pi, ps->next->buffer, store_read_buffer_size(ps)); - } - while (store_read_buffer_next(ps)); -} -#endif /* PNG_READ_SUPPORTED */ - -/* The caller must fill this in: */ -static store_palette_entry * -store_write_palette(png_store *ps, int npalette) -{ - if (ps->pwrite == NULL) - store_log(ps, NULL, "attempt to write palette without write stream", 1); - - if (ps->palette != NULL) - png_error(ps->pwrite, "multiple store_write_palette calls"); - - /* This function can only return NULL if called with '0'! */ - if (npalette > 0) - { - ps->palette = voidcast(store_palette_entry*, malloc(npalette * - sizeof *ps->palette)); - - if (ps->palette == NULL) - png_error(ps->pwrite, "store new palette: OOM"); - - ps->npalette = npalette; - } - - return ps->palette; -} - -#ifdef PNG_READ_SUPPORTED -static store_palette_entry * -store_current_palette(png_store *ps, int *npalette) -{ - /* This is an internal error (the call has been made outside a read - * operation.) - */ - if (ps->current == NULL) - store_log(ps, ps->pread, "no current stream for palette", 1); - - /* The result may be null if there is no palette. */ - *npalette = ps->current->npalette; - return ps->current->palette; -} -#endif /* PNG_READ_SUPPORTED */ - -/***************************** MEMORY MANAGEMENT*** ***************************/ -#ifdef PNG_USER_MEM_SUPPORTED -/* A store_memory is simply the header for an allocated block of memory. The - * pointer returned to libpng is just after the end of the header block, the - * allocated memory is followed by a second copy of the 'mark'. - */ -typedef struct store_memory -{ - store_pool *pool; /* Originating pool */ - struct store_memory *next; /* Singly linked list */ - png_alloc_size_t size; /* Size of memory allocated */ - png_byte mark[4]; /* ID marker */ -} store_memory; - -/* Handle a fatal error in memory allocation. This calls png_error if the - * libpng struct is non-NULL, else it outputs a message and returns. This means - * that a memory problem while libpng is running will abort (png_error) the - * handling of particular file while one in cleanup (after the destroy of the - * struct has returned) will simply keep going and free (or attempt to free) - * all the memory. - */ -static void -store_pool_error(png_store *ps, png_const_structp pp, PNG_CONST char *msg) -{ - if (pp != NULL) - png_error(pp, msg); - - /* Else we have to do it ourselves. png_error eventually calls store_log, - * above. store_log accepts a NULL png_structp - it just changes what gets - * output by store_message. - */ - store_log(ps, pp, msg, 1 /* error */); -} - -static void -store_memory_free(png_const_structp pp, store_pool *pool, store_memory *memory) -{ - /* Note that pp may be NULL (see store_pool_delete below), the caller has - * found 'memory' in pool->list *and* unlinked this entry, so this is a valid - * pointer (for sure), but the contents may have been trashed. - */ - if (memory->pool != pool) - store_pool_error(pool->store, pp, "memory corrupted (pool)"); - - else if (memcmp(memory->mark, pool->mark, sizeof memory->mark) != 0) - store_pool_error(pool->store, pp, "memory corrupted (start)"); - - /* It should be safe to read the size field now. */ - else - { - png_alloc_size_t cb = memory->size; - - if (cb > pool->max) - store_pool_error(pool->store, pp, "memory corrupted (size)"); - - else if (memcmp((png_bytep)(memory+1)+cb, pool->mark, sizeof pool->mark) - != 0) - store_pool_error(pool->store, pp, "memory corrupted (end)"); - - /* Finally give the library a chance to find problems too: */ - else - { - pool->current -= cb; - free(memory); - } - } -} - -static void -store_pool_delete(png_store *ps, store_pool *pool) -{ - if (pool->list != NULL) - { - fprintf(stderr, "%s: %s %s: memory lost (list follows):\n", ps->test, - pool == &ps->read_memory_pool ? "read" : "write", - pool == &ps->read_memory_pool ? (ps->current != NULL ? - ps->current->name : "unknown file") : ps->wname); - ++ps->nerrors; - - do - { - store_memory *next = pool->list; - pool->list = next->next; - next->next = NULL; - - fprintf(stderr, "\t%lu bytes @ %p\n", - (unsigned long)next->size, (PNG_CONST void*)(next+1)); - /* The NULL means this will always return, even if the memory is - * corrupted. - */ - store_memory_free(NULL, pool, next); - } - while (pool->list != NULL); - } - - /* And reset the other fields too for the next time. */ - if (pool->max > pool->max_max) pool->max_max = pool->max; - pool->max = 0; - if (pool->current != 0) /* unexpected internal error */ - fprintf(stderr, "%s: %s %s: memory counter mismatch (internal error)\n", - ps->test, pool == &ps->read_memory_pool ? "read" : "write", - pool == &ps->read_memory_pool ? (ps->current != NULL ? - ps->current->name : "unknown file") : ps->wname); - pool->current = 0; - - if (pool->limit > pool->max_limit) - pool->max_limit = pool->limit; - - pool->limit = 0; - - if (pool->total > pool->max_total) - pool->max_total = pool->total; - - pool->total = 0; - - /* Get a new mark too. */ - store_pool_mark(pool->mark); -} - -/* The memory callbacks: */ -static png_voidp PNGCBAPI -store_malloc(png_structp ppIn, png_alloc_size_t cb) -{ - png_const_structp pp = ppIn; - store_pool *pool = voidcast(store_pool*, png_get_mem_ptr(pp)); - store_memory *new = voidcast(store_memory*, malloc(cb + (sizeof *new) + - (sizeof pool->mark))); - - if (new != NULL) - { - if (cb > pool->max) - pool->max = cb; - - pool->current += cb; - - if (pool->current > pool->limit) - pool->limit = pool->current; - - pool->total += cb; - - new->size = cb; - memcpy(new->mark, pool->mark, sizeof new->mark); - memcpy((png_byte*)(new+1) + cb, pool->mark, sizeof pool->mark); - new->pool = pool; - new->next = pool->list; - pool->list = new; - ++new; - } - - else - { - /* NOTE: the PNG user malloc function cannot use the png_ptr it is passed - * other than to retrieve the allocation pointer! libpng calls the - * store_malloc callback in two basic cases: - * - * 1) From png_malloc; png_malloc will do a png_error itself if NULL is - * returned. - * 2) From png_struct or png_info structure creation; png_malloc is - * to return so cleanup can be performed. - * - * To handle this store_malloc can log a message, but can't do anything - * else. - */ - store_log(pool->store, pp, "out of memory", 1 /* is_error */); - } - - return new; -} - -static void PNGCBAPI -store_free(png_structp ppIn, png_voidp memory) -{ - png_const_structp pp = ppIn; - store_pool *pool = voidcast(store_pool*, png_get_mem_ptr(pp)); - store_memory *this = voidcast(store_memory*, memory), **test; - - /* Because libpng calls store_free with a dummy png_struct when deleting - * png_struct or png_info via png_destroy_struct_2 it is necessary to check - * the passed in png_structp to ensure it is valid, and not pass it to - * png_error if it is not. - */ - if (pp != pool->store->pread && pp != pool->store->pwrite) - pp = NULL; - - /* First check that this 'memory' really is valid memory - it must be in the - * pool list. If it is, use the shared memory_free function to free it. - */ - --this; - for (test = &pool->list; *test != this; test = &(*test)->next) - { - if (*test == NULL) - { - store_pool_error(pool->store, pp, "bad pointer to free"); - return; - } - } - - /* Unlink this entry, *test == this. */ - *test = this->next; - this->next = NULL; - store_memory_free(pp, pool, this); -} -#endif /* PNG_USER_MEM_SUPPORTED */ - -/* Setup functions. */ -/* Cleanup when aborting a write or after storing the new file. */ -static void -store_write_reset(png_store *ps) -{ - if (ps->pwrite != NULL) - { - anon_context(ps); - - Try - png_destroy_write_struct(&ps->pwrite, &ps->piwrite); - - Catch_anonymous - { - /* memory corruption: continue. */ - } - - ps->pwrite = NULL; - ps->piwrite = NULL; - } - - /* And make sure that all the memory has been freed - this will output - * spurious errors in the case of memory corruption above, but this is safe. - */ -# ifdef PNG_USER_MEM_SUPPORTED - store_pool_delete(ps, &ps->write_memory_pool); -# endif - - store_freenew(ps); -} - -/* The following is the main write function, it returns a png_struct and, - * optionally, a png_info suitable for writiing a new PNG file. Use - * store_storefile above to record this file after it has been written. The - * returned libpng structures as destroyed by store_write_reset above. - */ -static png_structp -set_store_for_write(png_store *ps, png_infopp ppi, - PNG_CONST char * volatile name) -{ - anon_context(ps); - - Try - { - if (ps->pwrite != NULL) - png_error(ps->pwrite, "write store already in use"); - - store_write_reset(ps); - safecat(ps->wname, sizeof ps->wname, 0, name); - - /* Don't do the slow memory checks if doing a speed test, also if user - * memory is not supported we can't do it anyway. - */ -# ifdef PNG_USER_MEM_SUPPORTED - if (!ps->speed) - ps->pwrite = png_create_write_struct_2(PNG_LIBPNG_VER_STRING, - ps, store_error, store_warning, &ps->write_memory_pool, - store_malloc, store_free); - - else -# endif - ps->pwrite = png_create_write_struct(PNG_LIBPNG_VER_STRING, - ps, store_error, store_warning); - - png_set_write_fn(ps->pwrite, ps, store_write, store_flush); - -# ifdef PNG_SET_OPTION_SUPPORTED - { - int opt; - for (opt=0; opt<ps->noptions; ++opt) - if (png_set_option(ps->pwrite, ps->options[opt].option, - ps->options[opt].setting) == PNG_OPTION_INVALID) - png_error(ps->pwrite, "png option invalid"); - } -# endif - - if (ppi != NULL) - *ppi = ps->piwrite = png_create_info_struct(ps->pwrite); - } - - Catch_anonymous - return NULL; - - return ps->pwrite; -} - -/* Cleanup when finished reading (either due to error or in the success case). - * This routine exists even when there is no read support to make the code - * tidier (avoid a mass of ifdefs) and so easier to maintain. - */ -static void -store_read_reset(png_store *ps) -{ -# ifdef PNG_READ_SUPPORTED - if (ps->pread != NULL) - { - anon_context(ps); - - Try - png_destroy_read_struct(&ps->pread, &ps->piread, NULL); - - Catch_anonymous - { - /* error already output: continue */ - } - - ps->pread = NULL; - ps->piread = NULL; - } -# endif - -# ifdef PNG_USER_MEM_SUPPORTED - /* Always do this to be safe. */ - store_pool_delete(ps, &ps->read_memory_pool); -# endif - - ps->current = NULL; - ps->next = NULL; - ps->readpos = 0; - ps->validated = 0; -} - -#ifdef PNG_READ_SUPPORTED -static void -store_read_set(png_store *ps, png_uint_32 id) -{ - png_store_file *pf = ps->saved; - - while (pf != NULL) - { - if (pf->id == id) - { - ps->current = pf; - ps->next = NULL; - store_read_buffer_next(ps); - return; - } - - pf = pf->next; - } - - { - size_t pos; - char msg[FILE_NAME_SIZE+64]; - - pos = standard_name_from_id(msg, sizeof msg, 0, id); - pos = safecat(msg, sizeof msg, pos, ": file not found"); - png_error(ps->pread, msg); - } -} - -/* The main interface for reading a saved file - pass the id number of the file - * to retrieve. Ids must be unique or the earlier file will be hidden. The API - * returns a png_struct and, optionally, a png_info. Both of these will be - * destroyed by store_read_reset above. - */ -static png_structp -set_store_for_read(png_store *ps, png_infopp ppi, png_uint_32 id, - PNG_CONST char *name) -{ - /* Set the name for png_error */ - safecat(ps->test, sizeof ps->test, 0, name); - - if (ps->pread != NULL) - png_error(ps->pread, "read store already in use"); - - store_read_reset(ps); - - /* Both the create APIs can return NULL if used in their default mode - * (because there is no other way of handling an error because the jmp_buf - * by default is stored in png_struct and that has not been allocated!) - * However, given that store_error works correctly in these circumstances - * we don't ever expect NULL in this program. - */ -# ifdef PNG_USER_MEM_SUPPORTED - if (!ps->speed) - ps->pread = png_create_read_struct_2(PNG_LIBPNG_VER_STRING, ps, - store_error, store_warning, &ps->read_memory_pool, store_malloc, - store_free); - - else -# endif - ps->pread = png_create_read_struct(PNG_LIBPNG_VER_STRING, ps, store_error, - store_warning); - - if (ps->pread == NULL) - { - struct exception_context *the_exception_context = &ps->exception_context; - - store_log(ps, NULL, "png_create_read_struct returned NULL (unexpected)", - 1 /*error*/); - - Throw ps; - } - -# ifdef PNG_SET_OPTION_SUPPORTED - { - int opt; - for (opt=0; opt<ps->noptions; ++opt) - if (png_set_option(ps->pread, ps->options[opt].option, - ps->options[opt].setting) == PNG_OPTION_INVALID) - png_error(ps->pread, "png option invalid"); - } -# endif - - store_read_set(ps, id); - - if (ppi != NULL) - *ppi = ps->piread = png_create_info_struct(ps->pread); - - return ps->pread; -} -#endif /* PNG_READ_SUPPORTED */ - -/* The overall cleanup of a store simply calls the above then removes all the - * saved files. This does not delete the store itself. - */ -static void -store_delete(png_store *ps) -{ - store_write_reset(ps); - store_read_reset(ps); - store_freefile(&ps->saved); - store_image_free(ps, NULL); -} - -/*********************** PNG FILE MODIFICATION ON READ ************************/ -/* Files may be modified on read. The following structure contains a complete - * png_store together with extra members to handle modification and a special - * read callback for libpng. To use this the 'modifications' field must be set - * to a list of png_modification structures that actually perform the - * modification, otherwise a png_modifier is functionally equivalent to a - * png_store. There is a special read function, set_modifier_for_read, which - * replaces set_store_for_read. - */ -typedef enum modifier_state -{ - modifier_start, /* Initial value */ - modifier_signature, /* Have a signature */ - modifier_IHDR /* Have an IHDR */ -} modifier_state; - -typedef struct CIE_color -{ - /* A single CIE tristimulus value, representing the unique response of a - * standard observer to a variety of light spectra. The observer recognizes - * all spectra that produce this response as the same color, therefore this - * is effectively a description of a color. - */ - double X, Y, Z; -} CIE_color; - -typedef struct color_encoding -{ - /* A description of an (R,G,B) encoding of color (as defined above); this - * includes the actual colors of the (R,G,B) triples (1,0,0), (0,1,0) and - * (0,0,1) plus an encoding value that is used to encode the linear - * components R, G and B to give the actual values R^gamma, G^gamma and - * B^gamma that are stored. - */ - double gamma; /* Encoding (file) gamma of space */ - CIE_color red, green, blue; /* End points */ -} color_encoding; - -#ifdef PNG_READ_SUPPORTED -static double -chromaticity_x(CIE_color c) -{ - return c.X / (c.X + c.Y + c.Z); -} - -static double -chromaticity_y(CIE_color c) -{ - return c.Y / (c.X + c.Y + c.Z); -} - -static CIE_color -white_point(PNG_CONST color_encoding *encoding) -{ - CIE_color white; - - white.X = encoding->red.X + encoding->green.X + encoding->blue.X; - white.Y = encoding->red.Y + encoding->green.Y + encoding->blue.Y; - white.Z = encoding->red.Z + encoding->green.Z + encoding->blue.Z; - - return white; -} - -#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED -static void -normalize_color_encoding(color_encoding *encoding) -{ - PNG_CONST double whiteY = encoding->red.Y + encoding->green.Y + - encoding->blue.Y; - - if (whiteY != 1) - { - encoding->red.X /= whiteY; - encoding->red.Y /= whiteY; - encoding->red.Z /= whiteY; - encoding->green.X /= whiteY; - encoding->green.Y /= whiteY; - encoding->green.Z /= whiteY; - encoding->blue.X /= whiteY; - encoding->blue.Y /= whiteY; - encoding->blue.Z /= whiteY; - } -} -#endif - -static size_t -safecat_color_encoding(char *buffer, size_t bufsize, size_t pos, - PNG_CONST color_encoding *e, double encoding_gamma) -{ - if (e != 0) - { - if (encoding_gamma != 0) - pos = safecat(buffer, bufsize, pos, "("); - pos = safecat(buffer, bufsize, pos, "R("); - pos = safecatd(buffer, bufsize, pos, e->red.X, 4); - pos = safecat(buffer, bufsize, pos, ","); - pos = safecatd(buffer, bufsize, pos, e->red.Y, 4); - pos = safecat(buffer, bufsize, pos, ","); - pos = safecatd(buffer, bufsize, pos, e->red.Z, 4); - pos = safecat(buffer, bufsize, pos, "),G("); - pos = safecatd(buffer, bufsize, pos, e->green.X, 4); - pos = safecat(buffer, bufsize, pos, ","); - pos = safecatd(buffer, bufsize, pos, e->green.Y, 4); - pos = safecat(buffer, bufsize, pos, ","); - pos = safecatd(buffer, bufsize, pos, e->green.Z, 4); - pos = safecat(buffer, bufsize, pos, "),B("); - pos = safecatd(buffer, bufsize, pos, e->blue.X, 4); - pos = safecat(buffer, bufsize, pos, ","); - pos = safecatd(buffer, bufsize, pos, e->blue.Y, 4); - pos = safecat(buffer, bufsize, pos, ","); - pos = safecatd(buffer, bufsize, pos, e->blue.Z, 4); - pos = safecat(buffer, bufsize, pos, ")"); - if (encoding_gamma != 0) - pos = safecat(buffer, bufsize, pos, ")"); - } - - if (encoding_gamma != 0) - { - pos = safecat(buffer, bufsize, pos, "^"); - pos = safecatd(buffer, bufsize, pos, encoding_gamma, 5); - } - - return pos; -} -#endif /* PNG_READ_SUPPORTED */ - -typedef struct png_modifier -{ - png_store this; /* I am a png_store */ - struct png_modification *modifications; /* Changes to make */ - - modifier_state state; /* My state */ - - /* Information from IHDR: */ - png_byte bit_depth; /* From IHDR */ - png_byte colour_type; /* From IHDR */ - - /* While handling PLTE, IDAT and IEND these chunks may be pended to allow - * other chunks to be inserted. - */ - png_uint_32 pending_len; - png_uint_32 pending_chunk; - - /* Test values */ - double *gammas; - unsigned int ngammas; - unsigned int ngamma_tests; /* Number of gamma tests to run*/ - double current_gamma; /* 0 if not set */ - PNG_CONST color_encoding *encodings; - unsigned int nencodings; - PNG_CONST color_encoding *current_encoding; /* If an encoding has been set */ - unsigned int encoding_counter; /* For iteration */ - int encoding_ignored; /* Something overwrote it */ - - /* Control variables used to iterate through possible encodings, the - * following must be set to 0 and tested by the function that uses the - * png_modifier because the modifier only sets it to 1 (true.) - */ - unsigned int repeat :1; /* Repeat this transform test. */ - unsigned int test_uses_encoding :1; - - /* Lowest sbit to test (libpng fails for sbit < 8) */ - png_byte sbitlow; - - /* Error control - these are the limits on errors accepted by the gamma tests - * below. - */ - double maxout8; /* Maximum output value error */ - double maxabs8; /* Absolute sample error 0..1 */ - double maxcalc8; /* Absolute sample error 0..1 */ - double maxpc8; /* Percentage sample error 0..100% */ - double maxout16; /* Maximum output value error */ - double maxabs16; /* Absolute sample error 0..1 */ - double maxcalc16;/* Absolute sample error 0..1 */ - double maxcalcG; /* Absolute sample error 0..1 */ - double maxpc16; /* Percentage sample error 0..100% */ - - /* This is set by transforms that need to allow a higher limit, it is an - * internal check on pngvalid to ensure that the calculated error limits are - * not ridiculous; without this it is too easy to make a mistake in pngvalid - * that allows any value through. - */ - double limit; /* limit on error values, normally 4E-3 */ - - /* Log limits - values above this are logged, but not necessarily - * warned. - */ - double log8; /* Absolute error in 8 bits to log */ - double log16; /* Absolute error in 16 bits to log */ - - /* Logged 8 and 16 bit errors ('output' values): */ - double error_gray_2; - double error_gray_4; - double error_gray_8; - double error_gray_16; - double error_color_8; - double error_color_16; - double error_indexed; - - /* Flags: */ - /* Whether to call png_read_update_info, not png_read_start_image, and how - * many times to call it. - */ - int use_update_info; - - /* Whether or not to interlace. */ - int interlace_type :9; /* int, but must store '1' */ - - /* Run the standard tests? */ - unsigned int test_standard :1; - - /* Run the odd-sized image and interlace read/write tests? */ - unsigned int test_size :1; - - /* Run tests on reading with a combination of transforms, */ - unsigned int test_transform :1; - - /* When to use the use_input_precision option, this controls the gamma - * validation code checks. If set any value that is within the transformed - * range input-.5 to input+.5 will be accepted, otherwise the value must be - * within the normal limits. It should not be necessary to set this; the - * result should always be exact within the permitted error limits. - */ - unsigned int use_input_precision :1; - unsigned int use_input_precision_sbit :1; - unsigned int use_input_precision_16to8 :1; - - /* If set assume that the calculation bit depth is set by the input - * precision, not the output precision. - */ - unsigned int calculations_use_input_precision :1; - - /* If set assume that the calculations are done in 16 bits even if the sample - * depth is 8 bits. - */ - unsigned int assume_16_bit_calculations :1; - - /* Which gamma tests to run: */ - unsigned int test_gamma_threshold :1; - unsigned int test_gamma_transform :1; /* main tests */ - unsigned int test_gamma_sbit :1; - unsigned int test_gamma_scale16 :1; - unsigned int test_gamma_background :1; - unsigned int test_gamma_alpha_mode :1; - unsigned int test_gamma_expand16 :1; - unsigned int test_exhaustive :1; - - unsigned int log :1; /* Log max error */ - - /* Buffer information, the buffer size limits the size of the chunks that can - * be modified - they must fit (including header and CRC) into the buffer! - */ - size_t flush; /* Count of bytes to flush */ - size_t buffer_count; /* Bytes in buffer */ - size_t buffer_position; /* Position in buffer */ - png_byte buffer[1024]; -} png_modifier; - -/* This returns true if the test should be stopped now because it has already - * failed and it is running silently. - */ -static int fail(png_modifier *pm) -{ - return !pm->log && !pm->this.verbose && (pm->this.nerrors > 0 || - (pm->this.treat_warnings_as_errors && pm->this.nwarnings > 0)); -} - -static void -modifier_init(png_modifier *pm) -{ - memset(pm, 0, sizeof *pm); - store_init(&pm->this); - pm->modifications = NULL; - pm->state = modifier_start; - pm->sbitlow = 1U; - pm->ngammas = 0; - pm->ngamma_tests = 0; - pm->gammas = 0; - pm->current_gamma = 0; - pm->encodings = 0; - pm->nencodings = 0; - pm->current_encoding = 0; - pm->encoding_counter = 0; - pm->encoding_ignored = 0; - pm->repeat = 0; - pm->test_uses_encoding = 0; - pm->maxout8 = pm->maxpc8 = pm->maxabs8 = pm->maxcalc8 = 0; - pm->maxout16 = pm->maxpc16 = pm->maxabs16 = pm->maxcalc16 = 0; - pm->maxcalcG = 0; - pm->limit = 4E-3; - pm->log8 = pm->log16 = 0; /* Means 'off' */ - pm->error_gray_2 = pm->error_gray_4 = pm->error_gray_8 = 0; - pm->error_gray_16 = pm->error_color_8 = pm->error_color_16 = 0; - pm->error_indexed = 0; - pm->use_update_info = 0; - pm->interlace_type = PNG_INTERLACE_NONE; - pm->test_standard = 0; - pm->test_size = 0; - pm->test_transform = 0; - pm->use_input_precision = 0; - pm->use_input_precision_sbit = 0; - pm->use_input_precision_16to8 = 0; - pm->calculations_use_input_precision = 0; - pm->assume_16_bit_calculations = 0; - pm->test_gamma_threshold = 0; - pm->test_gamma_transform = 0; - pm->test_gamma_sbit = 0; - pm->test_gamma_scale16 = 0; - pm->test_gamma_background = 0; - pm->test_gamma_alpha_mode = 0; - pm->test_gamma_expand16 = 0; - pm->test_exhaustive = 0; - pm->log = 0; - - /* Rely on the memset for all the other fields - there are no pointers */ -} - -#ifdef PNG_READ_TRANSFORMS_SUPPORTED - -/* This controls use of checks that explicitly know how libpng digitizes the - * samples in calculations; setting this circumvents simple error limit checking - * in the rgb_to_gray check, replacing it with an exact copy of the libpng 1.5 - * algorithm. - */ -#define DIGITIZE PNG_LIBPNG_VER < 10700 - -/* If pm->calculations_use_input_precision is set then operations will happen - * with the precision of the input, not the precision of the output depth. - * - * If pm->assume_16_bit_calculations is set then even 8 bit calculations use 16 - * bit precision. This only affects those of the following limits that pertain - * to a calculation - not a digitization operation - unless the following API is - * called directly. - */ -#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED -#if DIGITIZE -static double digitize(double value, int depth, int do_round) -{ - /* 'value' is in the range 0 to 1, the result is the same value rounded to a - * multiple of the digitization factor - 8 or 16 bits depending on both the - * sample depth and the 'assume' setting. Digitization is normally by - * rounding and 'do_round' should be 1, if it is 0 the digitized value will - * be truncated. - */ - PNG_CONST unsigned int digitization_factor = (1U << depth) -1; - - /* Limiting the range is done as a convenience to the caller - it's easier to - * do it once here than every time at the call site. - */ - if (value <= 0) - value = 0; - - else if (value >= 1) - value = 1; - - value *= digitization_factor; - if (do_round) value += .5; - return floor(value)/digitization_factor; -} -#endif -#endif /* RGB_TO_GRAY */ - -#ifdef PNG_READ_GAMMA_SUPPORTED -static double abserr(PNG_CONST png_modifier *pm, int in_depth, int out_depth) -{ - /* Absolute error permitted in linear values - affected by the bit depth of - * the calculations. - */ - if (pm->assume_16_bit_calculations || - (pm->calculations_use_input_precision ? in_depth : out_depth) == 16) - return pm->maxabs16; - else - return pm->maxabs8; -} - -static double calcerr(PNG_CONST png_modifier *pm, int in_depth, int out_depth) -{ - /* Error in the linear composition arithmetic - only relevant when - * composition actually happens (0 < alpha < 1). - */ - if ((pm->calculations_use_input_precision ? in_depth : out_depth) == 16) - return pm->maxcalc16; - else if (pm->assume_16_bit_calculations) - return pm->maxcalcG; - else - return pm->maxcalc8; -} - -static double pcerr(PNG_CONST png_modifier *pm, int in_depth, int out_depth) -{ - /* Percentage error permitted in the linear values. Note that the specified - * value is a percentage but this routine returns a simple number. - */ - if (pm->assume_16_bit_calculations || - (pm->calculations_use_input_precision ? in_depth : out_depth) == 16) - return pm->maxpc16 * .01; - else - return pm->maxpc8 * .01; -} - -/* Output error - the error in the encoded value. This is determined by the - * digitization of the output so can be +/-0.5 in the actual output value. In - * the expand_16 case with the current code in libpng the expand happens after - * all the calculations are done in 8 bit arithmetic, so even though the output - * depth is 16 the output error is determined by the 8 bit calculation. - * - * This limit is not determined by the bit depth of internal calculations. - * - * The specified parameter does *not* include the base .5 digitization error but - * it is added here. - */ -static double outerr(PNG_CONST png_modifier *pm, int in_depth, int out_depth) -{ - /* There is a serious error in the 2 and 4 bit grayscale transform because - * the gamma table value (8 bits) is simply shifted, not rounded, so the - * error in 4 bit grayscale gamma is up to the value below. This is a hack - * to allow pngvalid to succeed: - * - * TODO: fix this in libpng - */ - if (out_depth == 2) - return .73182-.5; - - if (out_depth == 4) - return .90644-.5; - - if ((pm->calculations_use_input_precision ? in_depth : out_depth) == 16) - return pm->maxout16; - - /* This is the case where the value was calculated at 8-bit precision then - * scaled to 16 bits. - */ - else if (out_depth == 16) - return pm->maxout8 * 257; - - else - return pm->maxout8; -} - -/* This does the same thing as the above however it returns the value to log, - * rather than raising a warning. This is useful for debugging to track down - * exactly what set of parameters cause high error values. - */ -static double outlog(PNG_CONST png_modifier *pm, int in_depth, int out_depth) -{ - /* The command line parameters are either 8 bit (0..255) or 16 bit (0..65535) - * and so must be adjusted for low bit depth grayscale: - */ - if (out_depth <= 8) - { - if (pm->log8 == 0) /* switched off */ - return 256; - - if (out_depth < 8) - return pm->log8 / 255 * ((1<<out_depth)-1); - - return pm->log8; - } - - if ((pm->calculations_use_input_precision ? in_depth : out_depth) == 16) - { - if (pm->log16 == 0) - return 65536; - - return pm->log16; - } - - /* This is the case where the value was calculated at 8-bit precision then - * scaled to 16 bits. - */ - if (pm->log8 == 0) - return 65536; - - return pm->log8 * 257; -} - -/* This complements the above by providing the appropriate quantization for the - * final value. Normally this would just be quantization to an integral value, - * but in the 8 bit calculation case it's actually quantization to a multiple of - * 257! - */ -static int output_quantization_factor(PNG_CONST png_modifier *pm, int in_depth, - int out_depth) -{ - if (out_depth == 16 && in_depth != 16 && - pm->calculations_use_input_precision) - return 257; - else - return 1; -} -#endif /* PNG_READ_GAMMA_SUPPORTED */ - -/* One modification structure must be provided for each chunk to be modified (in - * fact more than one can be provided if multiple separate changes are desired - * for a single chunk.) Modifications include adding a new chunk when a - * suitable chunk does not exist. - * - * The caller of modify_fn will reset the CRC of the chunk and record 'modified' - * or 'added' as appropriate if the modify_fn returns 1 (true). If the - * modify_fn is NULL the chunk is simply removed. - */ -typedef struct png_modification -{ - struct png_modification *next; - png_uint_32 chunk; - - /* If the following is NULL all matching chunks will be removed: */ - int (*modify_fn)(struct png_modifier *pm, - struct png_modification *me, int add); - - /* If the following is set to PLTE, IDAT or IEND and the chunk has not been - * found and modified (and there is a modify_fn) the modify_fn will be called - * to add the chunk before the relevant chunk. - */ - png_uint_32 add; - unsigned int modified :1; /* Chunk was modified */ - unsigned int added :1; /* Chunk was added */ - unsigned int removed :1; /* Chunk was removed */ -} png_modification; - -static void -modification_reset(png_modification *pmm) -{ - if (pmm != NULL) - { - pmm->modified = 0; - pmm->added = 0; - pmm->removed = 0; - modification_reset(pmm->next); - } -} - -static void -modification_init(png_modification *pmm) -{ - memset(pmm, 0, sizeof *pmm); - pmm->next = NULL; - pmm->chunk = 0; - pmm->modify_fn = NULL; - pmm->add = 0; - modification_reset(pmm); -} - -#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED -static void -modifier_current_encoding(PNG_CONST png_modifier *pm, color_encoding *ce) -{ - if (pm->current_encoding != 0) - *ce = *pm->current_encoding; - - else - memset(ce, 0, sizeof *ce); - - ce->gamma = pm->current_gamma; -} -#endif - -static size_t -safecat_current_encoding(char *buffer, size_t bufsize, size_t pos, - PNG_CONST png_modifier *pm) -{ - pos = safecat_color_encoding(buffer, bufsize, pos, pm->current_encoding, - pm->current_gamma); - - if (pm->encoding_ignored) - pos = safecat(buffer, bufsize, pos, "[overridden]"); - - return pos; -} - -/* Iterate through the usefully testable color encodings. An encoding is one - * of: - * - * 1) Nothing (no color space, no gamma). - * 2) Just a gamma value from the gamma array (including 1.0) - * 3) A color space from the encodings array with the corresponding gamma. - * 4) The same, but with gamma 1.0 (only really useful with 16 bit calculations) - * - * The iterator selects these in turn, the randomizer selects one at random, - * which is used depends on the setting of the 'test_exhaustive' flag. Notice - * that this function changes the colour space encoding so it must only be - * called on completion of the previous test. This is what 'modifier_reset' - * does, below. - * - * After the function has been called the 'repeat' flag will still be set; the - * caller of modifier_reset must reset it at the start of each run of the test! - */ -static unsigned int -modifier_total_encodings(PNG_CONST png_modifier *pm) -{ - return 1 + /* (1) nothing */ - pm->ngammas + /* (2) gamma values to test */ - pm->nencodings + /* (3) total number of encodings */ - /* The following test only works after the first time through the - * png_modifier code because 'bit_depth' is set when the IHDR is read. - * modifier_reset, below, preserves the setting until after it has called - * the iterate function (also below.) - * - * For this reason do not rely on this function outside a call to - * modifier_reset. - */ - ((pm->bit_depth == 16 || pm->assume_16_bit_calculations) ? - pm->nencodings : 0); /* (4) encodings with gamma == 1.0 */ -} - -static void -modifier_encoding_iterate(png_modifier *pm) -{ - if (!pm->repeat && /* Else something needs the current encoding again. */ - pm->test_uses_encoding) /* Some transform is encoding dependent */ - { - if (pm->test_exhaustive) - { - if (++pm->encoding_counter >= modifier_total_encodings(pm)) - pm->encoding_counter = 0; /* This will stop the repeat */ - } - - else - { - /* Not exhaustive - choose an encoding at random; generate a number in - * the range 1..(max-1), so the result is always non-zero: - */ - if (pm->encoding_counter == 0) - pm->encoding_counter = random_mod(modifier_total_encodings(pm)-1)+1; - else - pm->encoding_counter = 0; - } - - if (pm->encoding_counter > 0) - pm->repeat = 1; - } - - else if (!pm->repeat) - pm->encoding_counter = 0; -} - -static void -modifier_reset(png_modifier *pm) -{ - store_read_reset(&pm->this); - pm->limit = 4E-3; - pm->pending_len = pm->pending_chunk = 0; - pm->flush = pm->buffer_count = pm->buffer_position = 0; - pm->modifications = NULL; - pm->state = modifier_start; - modifier_encoding_iterate(pm); - /* The following must be set in the next run. In particular - * test_uses_encodings must be set in the _ini function of each transform - * that looks at the encodings. (Not the 'add' function!) - */ - pm->test_uses_encoding = 0; - pm->current_gamma = 0; - pm->current_encoding = 0; - pm->encoding_ignored = 0; - /* These only become value after IHDR is read: */ - pm->bit_depth = pm->colour_type = 0; -} - -/* The following must be called before anything else to get the encoding set up - * on the modifier. In particular it must be called before the transform init - * functions are called. - */ -static void -modifier_set_encoding(png_modifier *pm) -{ - /* Set the encoding to the one specified by the current encoding counter, - * first clear out all the settings - this corresponds to an encoding_counter - * of 0. - */ - pm->current_gamma = 0; - pm->current_encoding = 0; - pm->encoding_ignored = 0; /* not ignored yet - happens in _ini functions. */ - - /* Now, if required, set the gamma and encoding fields. */ - if (pm->encoding_counter > 0) - { - /* The gammas[] array is an array of screen gammas, not encoding gammas, - * so we need the inverse: - */ - if (pm->encoding_counter <= pm->ngammas) - pm->current_gamma = 1/pm->gammas[pm->encoding_counter-1]; - - else - { - unsigned int i = pm->encoding_counter - pm->ngammas; - - if (i >= pm->nencodings) - { - i %= pm->nencodings; - pm->current_gamma = 1; /* Linear, only in the 16 bit case */ - } - - else - pm->current_gamma = pm->encodings[i].gamma; - - pm->current_encoding = pm->encodings + i; - } - } -} - -/* Enquiry functions to find out what is set. Notice that there is an implicit - * assumption below that the first encoding in the list is the one for sRGB. - */ -static int -modifier_color_encoding_is_sRGB(PNG_CONST png_modifier *pm) -{ - return pm->current_encoding != 0 && pm->current_encoding == pm->encodings && - pm->current_encoding->gamma == pm->current_gamma; -} - -static int -modifier_color_encoding_is_set(PNG_CONST png_modifier *pm) -{ - return pm->current_gamma != 0; -} - -/* Convenience macros. */ -#define CHUNK(a,b,c,d) (((a)<<24)+((b)<<16)+((c)<<8)+(d)) -#define CHUNK_IHDR CHUNK(73,72,68,82) -#define CHUNK_PLTE CHUNK(80,76,84,69) -#define CHUNK_IDAT CHUNK(73,68,65,84) -#define CHUNK_IEND CHUNK(73,69,78,68) -#define CHUNK_cHRM CHUNK(99,72,82,77) -#define CHUNK_gAMA CHUNK(103,65,77,65) -#define CHUNK_sBIT CHUNK(115,66,73,84) -#define CHUNK_sRGB CHUNK(115,82,71,66) - -/* The guts of modification are performed during a read. */ -static void -modifier_crc(png_bytep buffer) -{ - /* Recalculate the chunk CRC - a complete chunk must be in - * the buffer, at the start. - */ - uInt datalen = png_get_uint_32(buffer); - uLong crc = crc32(0, buffer+4, datalen+4); - /* The cast to png_uint_32 is safe because a crc32 is always a 32 bit value. - */ - png_save_uint_32(buffer+datalen+8, (png_uint_32)crc); -} - -static void -modifier_setbuffer(png_modifier *pm) -{ - modifier_crc(pm->buffer); - pm->buffer_count = png_get_uint_32(pm->buffer)+12; - pm->buffer_position = 0; -} - -/* Separate the callback into the actual implementation (which is passed the - * png_modifier explicitly) and the callback, which gets the modifier from the - * png_struct. - */ -static void -modifier_read_imp(png_modifier *pm, png_bytep pb, png_size_t st) -{ - while (st > 0) - { - size_t cb; - png_uint_32 len, chunk; - png_modification *mod; - - if (pm->buffer_position >= pm->buffer_count) switch (pm->state) - { - static png_byte sign[8] = { 137, 80, 78, 71, 13, 10, 26, 10 }; - case modifier_start: - store_read_imp(&pm->this, pm->buffer, 8); /* size of signature. */ - pm->buffer_count = 8; - pm->buffer_position = 0; - - if (memcmp(pm->buffer, sign, 8) != 0) - png_error(pm->this.pread, "invalid PNG file signature"); - pm->state = modifier_signature; - break; - - case modifier_signature: - store_read_imp(&pm->this, pm->buffer, 13+12); /* size of IHDR */ - pm->buffer_count = 13+12; - pm->buffer_position = 0; - - if (png_get_uint_32(pm->buffer) != 13 || - png_get_uint_32(pm->buffer+4) != CHUNK_IHDR) - png_error(pm->this.pread, "invalid IHDR"); - - /* Check the list of modifiers for modifications to the IHDR. */ - mod = pm->modifications; - while (mod != NULL) - { - if (mod->chunk == CHUNK_IHDR && mod->modify_fn && - (*mod->modify_fn)(pm, mod, 0)) - { - mod->modified = 1; - modifier_setbuffer(pm); - } - - /* Ignore removal or add if IHDR! */ - mod = mod->next; - } - - /* Cache information from the IHDR (the modified one.) */ - pm->bit_depth = pm->buffer[8+8]; - pm->colour_type = pm->buffer[8+8+1]; - - pm->state = modifier_IHDR; - pm->flush = 0; - break; - - case modifier_IHDR: - default: - /* Read a new chunk and process it until we see PLTE, IDAT or - * IEND. 'flush' indicates that there is still some data to - * output from the preceding chunk. - */ - if ((cb = pm->flush) > 0) - { - if (cb > st) cb = st; - pm->flush -= cb; - store_read_imp(&pm->this, pb, cb); - pb += cb; - st -= cb; - if (st == 0) return; - } - - /* No more bytes to flush, read a header, or handle a pending - * chunk. - */ - if (pm->pending_chunk != 0) - { - png_save_uint_32(pm->buffer, pm->pending_len); - png_save_uint_32(pm->buffer+4, pm->pending_chunk); - pm->pending_len = 0; - pm->pending_chunk = 0; - } - else - store_read_imp(&pm->this, pm->buffer, 8); - - pm->buffer_count = 8; - pm->buffer_position = 0; - - /* Check for something to modify or a terminator chunk. */ - len = png_get_uint_32(pm->buffer); - chunk = png_get_uint_32(pm->buffer+4); - - /* Terminators first, they may have to be delayed for added - * chunks - */ - if (chunk == CHUNK_PLTE || chunk == CHUNK_IDAT || - chunk == CHUNK_IEND) - { - mod = pm->modifications; - - while (mod != NULL) - { - if ((mod->add == chunk || - (mod->add == CHUNK_PLTE && chunk == CHUNK_IDAT)) && - mod->modify_fn != NULL && !mod->modified && !mod->added) - { - /* Regardless of what the modify function does do not run - * this again. - */ - mod->added = 1; - - if ((*mod->modify_fn)(pm, mod, 1 /*add*/)) - { - /* Reset the CRC on a new chunk */ - if (pm->buffer_count > 0) - modifier_setbuffer(pm); - - else - { - pm->buffer_position = 0; - mod->removed = 1; - } - - /* The buffer has been filled with something (we assume) - * so output this. Pend the current chunk. - */ - pm->pending_len = len; - pm->pending_chunk = chunk; - break; /* out of while */ - } - } - - mod = mod->next; - } - - /* Don't do any further processing if the buffer was modified - - * otherwise the code will end up modifying a chunk that was - * just added. - */ - if (mod != NULL) - break; /* out of switch */ - } - - /* If we get to here then this chunk may need to be modified. To - * do this it must be less than 1024 bytes in total size, otherwise - * it just gets flushed. - */ - if (len+12 <= sizeof pm->buffer) - { - store_read_imp(&pm->this, pm->buffer+pm->buffer_count, - len+12-pm->buffer_count); - pm->buffer_count = len+12; - - /* Check for a modification, else leave it be. */ - mod = pm->modifications; - while (mod != NULL) - { - if (mod->chunk == chunk) - { - if (mod->modify_fn == NULL) - { - /* Remove this chunk */ - pm->buffer_count = pm->buffer_position = 0; - mod->removed = 1; - break; /* Terminate the while loop */ - } - - else if ((*mod->modify_fn)(pm, mod, 0)) - { - mod->modified = 1; - /* The chunk may have been removed: */ - if (pm->buffer_count == 0) - { - pm->buffer_position = 0; - break; - } - modifier_setbuffer(pm); - } - } - - mod = mod->next; - } - } - - else - pm->flush = len+12 - pm->buffer_count; /* data + crc */ - - /* Take the data from the buffer (if there is any). */ - break; - } - - /* Here to read from the modifier buffer (not directly from - * the store, as in the flush case above.) - */ - cb = pm->buffer_count - pm->buffer_position; - - if (cb > st) - cb = st; - - memcpy(pb, pm->buffer + pm->buffer_position, cb); - st -= cb; - pb += cb; - pm->buffer_position += cb; - } -} - -/* The callback: */ -static void PNGCBAPI -modifier_read(png_structp ppIn, png_bytep pb, png_size_t st) -{ - png_const_structp pp = ppIn; - png_modifier *pm = voidcast(png_modifier*, png_get_io_ptr(pp)); - - if (pm == NULL || pm->this.pread != pp) - png_error(pp, "bad modifier_read call"); - - modifier_read_imp(pm, pb, st); -} - -/* Like store_progressive_read but the data is getting changed as we go so we - * need a local buffer. - */ -static void -modifier_progressive_read(png_modifier *pm, png_structp pp, png_infop pi) -{ - if (pm->this.pread != pp || pm->this.current == NULL || - pm->this.next == NULL) - png_error(pp, "store state damaged (progressive)"); - - /* This is another Horowitz and Hill random noise generator. In this case - * the aim is to stress the progressive reader with truly horrible variable - * buffer sizes in the range 1..500, so a sequence of 9 bit random numbers - * is generated. We could probably just count from 1 to 32767 and get as - * good a result. - */ - for (;;) - { - static png_uint_32 noise = 1; - png_size_t cb, cbAvail; - png_byte buffer[512]; - - /* Generate 15 more bits of stuff: */ - noise = (noise << 9) | ((noise ^ (noise >> (9-5))) & 0x1ff); - cb = noise & 0x1ff; - - /* Check that this number of bytes are available (in the current buffer.) - * (This doesn't quite work - the modifier might delete a chunk; unlikely - * but possible, it doesn't happen at present because the modifier only - * adds chunks to standard images.) - */ - cbAvail = store_read_buffer_avail(&pm->this); - if (pm->buffer_count > pm->buffer_position) - cbAvail += pm->buffer_count - pm->buffer_position; - - if (cb > cbAvail) - { - /* Check for EOF: */ - if (cbAvail == 0) - break; - - cb = cbAvail; - } - - modifier_read_imp(pm, buffer, cb); - png_process_data(pp, pi, buffer, cb); - } - - /* Check the invariants at the end (if this fails it's a problem in this - * file!) - */ - if (pm->buffer_count > pm->buffer_position || - pm->this.next != &pm->this.current->data || - pm->this.readpos < pm->this.current->datacount) - png_error(pp, "progressive read implementation error"); -} - -/* Set up a modifier. */ -static png_structp -set_modifier_for_read(png_modifier *pm, png_infopp ppi, png_uint_32 id, - PNG_CONST char *name) -{ - /* Do this first so that the modifier fields are cleared even if an error - * happens allocating the png_struct. No allocation is done here so no - * cleanup is required. - */ - pm->state = modifier_start; - pm->bit_depth = 0; - pm->colour_type = 255; - - pm->pending_len = 0; - pm->pending_chunk = 0; - pm->flush = 0; - pm->buffer_count = 0; - pm->buffer_position = 0; - - return set_store_for_read(&pm->this, ppi, id, name); -} - - -/******************************** MODIFICATIONS *******************************/ -/* Standard modifications to add chunks. These do not require the _SUPPORTED - * macros because the chunks can be there regardless of whether this specific - * libpng supports them. - */ -typedef struct gama_modification -{ - png_modification this; - png_fixed_point gamma; -} gama_modification; - -static int -gama_modify(png_modifier *pm, png_modification *me, int add) -{ - UNUSED(add) - /* This simply dumps the given gamma value into the buffer. */ - png_save_uint_32(pm->buffer, 4); - png_save_uint_32(pm->buffer+4, CHUNK_gAMA); - png_save_uint_32(pm->buffer+8, ((gama_modification*)me)->gamma); - return 1; -} - -static void -gama_modification_init(gama_modification *me, png_modifier *pm, double gammad) -{ - double g; - - modification_init(&me->this); - me->this.chunk = CHUNK_gAMA; - me->this.modify_fn = gama_modify; - me->this.add = CHUNK_PLTE; - g = fix(gammad); - me->gamma = (png_fixed_point)g; - me->this.next = pm->modifications; - pm->modifications = &me->this; -} - -typedef struct chrm_modification -{ - png_modification this; - PNG_CONST color_encoding *encoding; - png_fixed_point wx, wy, rx, ry, gx, gy, bx, by; -} chrm_modification; - -static int -chrm_modify(png_modifier *pm, png_modification *me, int add) -{ - UNUSED(add) - /* As with gAMA this just adds the required cHRM chunk to the buffer. */ - png_save_uint_32(pm->buffer , 32); - png_save_uint_32(pm->buffer+ 4, CHUNK_cHRM); - png_save_uint_32(pm->buffer+ 8, ((chrm_modification*)me)->wx); - png_save_uint_32(pm->buffer+12, ((chrm_modification*)me)->wy); - png_save_uint_32(pm->buffer+16, ((chrm_modification*)me)->rx); - png_save_uint_32(pm->buffer+20, ((chrm_modification*)me)->ry); - png_save_uint_32(pm->buffer+24, ((chrm_modification*)me)->gx); - png_save_uint_32(pm->buffer+28, ((chrm_modification*)me)->gy); - png_save_uint_32(pm->buffer+32, ((chrm_modification*)me)->bx); - png_save_uint_32(pm->buffer+36, ((chrm_modification*)me)->by); - return 1; -} - -static void -chrm_modification_init(chrm_modification *me, png_modifier *pm, - PNG_CONST color_encoding *encoding) -{ - CIE_color white = white_point(encoding); - - /* Original end points: */ - me->encoding = encoding; - - /* Chromaticities (in fixed point): */ - me->wx = fix(chromaticity_x(white)); - me->wy = fix(chromaticity_y(white)); - - me->rx = fix(chromaticity_x(encoding->red)); - me->ry = fix(chromaticity_y(encoding->red)); - me->gx = fix(chromaticity_x(encoding->green)); - me->gy = fix(chromaticity_y(encoding->green)); - me->bx = fix(chromaticity_x(encoding->blue)); - me->by = fix(chromaticity_y(encoding->blue)); - - modification_init(&me->this); - me->this.chunk = CHUNK_cHRM; - me->this.modify_fn = chrm_modify; - me->this.add = CHUNK_PLTE; - me->this.next = pm->modifications; - pm->modifications = &me->this; -} - -typedef struct srgb_modification -{ - png_modification this; - png_byte intent; -} srgb_modification; - -static int -srgb_modify(png_modifier *pm, png_modification *me, int add) -{ - UNUSED(add) - /* As above, ignore add and just make a new chunk */ - png_save_uint_32(pm->buffer, 1); - png_save_uint_32(pm->buffer+4, CHUNK_sRGB); - pm->buffer[8] = ((srgb_modification*)me)->intent; - return 1; -} - -static void -srgb_modification_init(srgb_modification *me, png_modifier *pm, png_byte intent) -{ - modification_init(&me->this); - me->this.chunk = CHUNK_sBIT; - - if (intent <= 3) /* if valid, else *delete* sRGB chunks */ - { - me->this.modify_fn = srgb_modify; - me->this.add = CHUNK_PLTE; - me->intent = intent; - } - - else - { - me->this.modify_fn = 0; - me->this.add = 0; - me->intent = 0; - } - - me->this.next = pm->modifications; - pm->modifications = &me->this; -} - -#ifdef PNG_READ_GAMMA_SUPPORTED -typedef struct sbit_modification -{ - png_modification this; - png_byte sbit; -} sbit_modification; - -static int -sbit_modify(png_modifier *pm, png_modification *me, int add) -{ - png_byte sbit = ((sbit_modification*)me)->sbit; - if (pm->bit_depth > sbit) - { - int cb = 0; - switch (pm->colour_type) - { - case 0: - cb = 1; - break; - - case 2: - case 3: - cb = 3; - break; - - case 4: - cb = 2; - break; - - case 6: - cb = 4; - break; - - default: - png_error(pm->this.pread, - "unexpected colour type in sBIT modification"); - } - - png_save_uint_32(pm->buffer, cb); - png_save_uint_32(pm->buffer+4, CHUNK_sBIT); - - while (cb > 0) - (pm->buffer+8)[--cb] = sbit; - - return 1; - } - else if (!add) - { - /* Remove the sBIT chunk */ - pm->buffer_count = pm->buffer_position = 0; - return 1; - } - else - return 0; /* do nothing */ -} - -static void -sbit_modification_init(sbit_modification *me, png_modifier *pm, png_byte sbit) -{ - modification_init(&me->this); - me->this.chunk = CHUNK_sBIT; - me->this.modify_fn = sbit_modify; - me->this.add = CHUNK_PLTE; - me->sbit = sbit; - me->this.next = pm->modifications; - pm->modifications = &me->this; -} -#endif /* PNG_READ_GAMMA_SUPPORTED */ -#endif /* PNG_READ_TRANSFORMS_SUPPORTED */ - -/***************************** STANDARD PNG FILES *****************************/ -/* Standard files - write and save standard files. */ -/* There are two basic forms of standard images. Those which attempt to have - * all the possible pixel values (not possible for 16bpp images, but a range of - * values are produced) and those which have a range of image sizes. The former - * are used for testing transforms, in particular gamma correction and bit - * reduction and increase. The latter are reserved for testing the behavior of - * libpng with respect to 'odd' image sizes - particularly small images where - * rows become 1 byte and interlace passes disappear. - * - * The first, most useful, set are the 'transform' images, the second set of - * small images are the 'size' images. - * - * The transform files are constructed with rows which fit into a 1024 byte row - * buffer. This makes allocation easier below. Further regardless of the file - * format every row has 128 pixels (giving 1024 bytes for 64bpp formats). - * - * Files are stored with no gAMA or sBIT chunks, with a PLTE only when needed - * and with an ID derived from the colour type, bit depth and interlace type - * as above (FILEID). The width (128) and height (variable) are not stored in - * the FILEID - instead the fields are set to 0, indicating a transform file. - * - * The size files ar constructed with rows a maximum of 128 bytes wide, allowing - * a maximum width of 16 pixels (for the 64bpp case.) They also have a maximum - * height of 16 rows. The width and height are stored in the FILEID and, being - * non-zero, indicate a size file. - * - * Because the PNG filter code is typically the largest CPU consumer within - * libpng itself there is a tendency to attempt to optimize it. This results in - * special case code which needs to be validated. To cause this to happen the - * 'size' images are made to use each possible filter, in so far as this is - * possible for smaller images. - * - * For palette image (colour type 3) multiple transform images are stored with - * the same bit depth to allow testing of more colour combinations - - * particularly important for testing the gamma code because libpng uses a - * different code path for palette images. For size images a single palette is - * used. - */ - -/* Make a 'standard' palette. Because there are only 256 entries in a palette - * (maximum) this actually makes a random palette in the hope that enough tests - * will catch enough errors. (Note that the same palette isn't produced every - * time for the same test - it depends on what previous tests have been run - - * but a given set of arguments to pngvalid will always produce the same palette - * at the same test! This is why pseudo-random number generators are useful for - * testing.) - * - * The store must be open for write when this is called, otherwise an internal - * error will occur. This routine contains its own magic number seed, so the - * palettes generated don't change if there are intervening errors (changing the - * calls to the store_mark seed.) - */ -static store_palette_entry * -make_standard_palette(png_store* ps, int npalette, int do_tRNS) -{ - static png_uint_32 palette_seed[2] = { 0x87654321, 9 }; - - int i = 0; - png_byte values[256][4]; - - /* Always put in black and white plus the six primary and secondary colors. - */ - for (; i<8; ++i) - { - values[i][1] = (png_byte)((i&1) ? 255U : 0U); - values[i][2] = (png_byte)((i&2) ? 255U : 0U); - values[i][3] = (png_byte)((i&4) ? 255U : 0U); - } - - /* Then add 62 grays (one quarter of the remaining 256 slots). */ - { - int j = 0; - png_byte random_bytes[4]; - png_byte need[256]; - - need[0] = 0; /*got black*/ - memset(need+1, 1, (sizeof need)-2); /*need these*/ - need[255] = 0; /*but not white*/ - - while (i<70) - { - png_byte b; - - if (j==0) - { - make_four_random_bytes(palette_seed, random_bytes); - j = 4; - } - - b = random_bytes[--j]; - if (need[b]) - { - values[i][1] = b; - values[i][2] = b; - values[i++][3] = b; - } - } - } - - /* Finally add 192 colors at random - don't worry about matches to things we - * already have, chance is less than 1/65536. Don't worry about grays, - * chance is the same, so we get a duplicate or extra gray less than 1 time - * in 170. - */ - for (; i<256; ++i) - make_four_random_bytes(palette_seed, values[i]); - - /* Fill in the alpha values in the first byte. Just use all possible values - * (0..255) in an apparently random order: - */ - { - store_palette_entry *palette; - png_byte selector[4]; - - make_four_random_bytes(palette_seed, selector); - - if (do_tRNS) - for (i=0; i<256; ++i) - values[i][0] = (png_byte)(i ^ selector[0]); - - else - for (i=0; i<256; ++i) - values[i][0] = 255; /* no transparency/tRNS chunk */ - - /* 'values' contains 256 ARGB values, but we only need 'npalette'. - * 'npalette' will always be a power of 2: 2, 4, 16 or 256. In the low - * bit depth cases select colors at random, else it is difficult to have - * a set of low bit depth palette test with any chance of a reasonable - * range of colors. Do this by randomly permuting values into the low - * 'npalette' entries using an XOR mask generated here. This also - * permutes the npalette == 256 case in a potentially useful way (there is - * no relationship between palette index and the color value therein!) - */ - palette = store_write_palette(ps, npalette); - - for (i=0; i<npalette; ++i) - { - palette[i].alpha = values[i ^ selector[1]][0]; - palette[i].red = values[i ^ selector[1]][1]; - palette[i].green = values[i ^ selector[1]][2]; - palette[i].blue = values[i ^ selector[1]][3]; - } - - return palette; - } -} - -/* Initialize a standard palette on a write stream. The 'do_tRNS' argument - * indicates whether or not to also set the tRNS chunk. - */ -/* TODO: the png_structp here can probably be 'const' in the future */ -static void -init_standard_palette(png_store *ps, png_structp pp, png_infop pi, int npalette, - int do_tRNS) -{ - store_palette_entry *ppal = make_standard_palette(ps, npalette, do_tRNS); - - { - int i; - png_color palette[256]; - - /* Set all entries to detect overread errors. */ - for (i=0; i<npalette; ++i) - { - palette[i].red = ppal[i].red; - palette[i].green = ppal[i].green; - palette[i].blue = ppal[i].blue; - } - - /* Just in case fill in the rest with detectable values: */ - for (; i<256; ++i) - palette[i].red = palette[i].green = palette[i].blue = 42; - - png_set_PLTE(pp, pi, palette, npalette); - } - - if (do_tRNS) - { - int i, j; - png_byte tRNS[256]; - - /* Set all the entries, but skip trailing opaque entries */ - for (i=j=0; i<npalette; ++i) - if ((tRNS[i] = ppal[i].alpha) < 255) - j = i+1; - - /* Fill in the remainder with a detectable value: */ - for (; i<256; ++i) - tRNS[i] = 24; - -# ifdef PNG_WRITE_tRNS_SUPPORTED - if (j > 0) - png_set_tRNS(pp, pi, tRNS, j, 0/*color*/); -# endif - } -} - -/* The number of passes is related to the interlace type. There was no libpng - * API to determine this prior to 1.5, so we need an inquiry function: - */ -static int -npasses_from_interlace_type(png_const_structp pp, int interlace_type) -{ - switch (interlace_type) - { - default: - png_error(pp, "invalid interlace type"); - - case PNG_INTERLACE_NONE: - return 1; - - case PNG_INTERLACE_ADAM7: - return PNG_INTERLACE_ADAM7_PASSES; - } -} - -static unsigned int -bit_size(png_const_structp pp, png_byte colour_type, png_byte bit_depth) -{ - switch (colour_type) - { - default: png_error(pp, "invalid color type"); - - case 0: return bit_depth; - - case 2: return 3*bit_depth; - - case 3: return bit_depth; - - case 4: return 2*bit_depth; - - case 6: return 4*bit_depth; - } -} - -#define TRANSFORM_WIDTH 128U -#define TRANSFORM_ROWMAX (TRANSFORM_WIDTH*8U) -#define SIZE_ROWMAX (16*8U) /* 16 pixels, max 8 bytes each - 128 bytes */ -#define STANDARD_ROWMAX TRANSFORM_ROWMAX /* The larger of the two */ -#define SIZE_HEIGHTMAX 16 /* Maximum range of size images */ - -static size_t -transform_rowsize(png_const_structp pp, png_byte colour_type, - png_byte bit_depth) -{ - return (TRANSFORM_WIDTH * bit_size(pp, colour_type, bit_depth)) / 8; -} - -/* transform_width(pp, colour_type, bit_depth) current returns the same number - * every time, so just use a macro: - */ -#define transform_width(pp, colour_type, bit_depth) TRANSFORM_WIDTH - -static png_uint_32 -transform_height(png_const_structp pp, png_byte colour_type, png_byte bit_depth) -{ - switch (bit_size(pp, colour_type, bit_depth)) - { - case 1: - case 2: - case 4: - return 1; /* Total of 128 pixels */ - - case 8: - return 2; /* Total of 256 pixels/bytes */ - - case 16: - return 512; /* Total of 65536 pixels */ - - case 24: - case 32: - return 512; /* 65536 pixels */ - - case 48: - case 64: - return 2048;/* 4 x 65536 pixels. */ -# define TRANSFORM_HEIGHTMAX 2048 - - default: - return 0; /* Error, will be caught later */ - } -} - -#ifdef PNG_READ_SUPPORTED -/* The following can only be defined here, now we have the definitions - * of the transform image sizes. - */ -static png_uint_32 -standard_width(png_const_structp pp, png_uint_32 id) -{ - png_uint_32 width = WIDTH_FROM_ID(id); - UNUSED(pp) - - if (width == 0) - width = transform_width(pp, COL_FROM_ID(id), DEPTH_FROM_ID(id)); - - return width; -} - -static png_uint_32 -standard_height(png_const_structp pp, png_uint_32 id) -{ - png_uint_32 height = HEIGHT_FROM_ID(id); - - if (height == 0) - height = transform_height(pp, COL_FROM_ID(id), DEPTH_FROM_ID(id)); - - return height; -} - -static png_uint_32 -standard_rowsize(png_const_structp pp, png_uint_32 id) -{ - png_uint_32 width = standard_width(pp, id); - - /* This won't overflow: */ - width *= bit_size(pp, COL_FROM_ID(id), DEPTH_FROM_ID(id)); - return (width + 7) / 8; -} -#endif /* PNG_READ_SUPPORTED */ - -static void -transform_row(png_const_structp pp, png_byte buffer[TRANSFORM_ROWMAX], - png_byte colour_type, png_byte bit_depth, png_uint_32 y) -{ - png_uint_32 v = y << 7; - png_uint_32 i = 0; - - switch (bit_size(pp, colour_type, bit_depth)) - { - case 1: - while (i<128/8) buffer[i] = (png_byte)(v & 0xff), v += 17, ++i; - return; - - case 2: - while (i<128/4) buffer[i] = (png_byte)(v & 0xff), v += 33, ++i; - return; - - case 4: - while (i<128/2) buffer[i] = (png_byte)(v & 0xff), v += 65, ++i; - return; - - case 8: - /* 256 bytes total, 128 bytes in each row set as follows: */ - while (i<128) buffer[i] = (png_byte)(v & 0xff), ++v, ++i; - return; - - case 16: - /* Generate all 65536 pixel values in order, which includes the 8 bit - * GA case as well as the 16 bit G case. - */ - while (i<128) - { - buffer[2*i] = (png_byte)((v>>8) & 0xff); - buffer[2*i+1] = (png_byte)(v & 0xff); - ++v; - ++i; - } - - return; - - case 24: - /* 65535 pixels, but rotate the values. */ - while (i<128) - { - /* Three bytes per pixel, r, g, b, make b by r^g */ - buffer[3*i+0] = (png_byte)((v >> 8) & 0xff); - buffer[3*i+1] = (png_byte)(v & 0xff); - buffer[3*i+2] = (png_byte)(((v >> 8) ^ v) & 0xff); - ++v; - ++i; - } - - return; - - case 32: - /* 65535 pixels, r, g, b, a; just replicate */ - while (i<128) - { - buffer[4*i+0] = (png_byte)((v >> 8) & 0xff); - buffer[4*i+1] = (png_byte)(v & 0xff); - buffer[4*i+2] = (png_byte)((v >> 8) & 0xff); - buffer[4*i+3] = (png_byte)(v & 0xff); - ++v; - ++i; - } - - return; - - case 48: - /* y is maximum 2047, giving 4x65536 pixels, make 'r' increase by 1 at - * each pixel, g increase by 257 (0x101) and 'b' by 0x1111: - */ - while (i<128) - { - png_uint_32 t = v++; - buffer[6*i+0] = (png_byte)((t >> 8) & 0xff); - buffer[6*i+1] = (png_byte)(t & 0xff); - t *= 257; - buffer[6*i+2] = (png_byte)((t >> 8) & 0xff); - buffer[6*i+3] = (png_byte)(t & 0xff); - t *= 17; - buffer[6*i+4] = (png_byte)((t >> 8) & 0xff); - buffer[6*i+5] = (png_byte)(t & 0xff); - ++i; - } - - return; - - case 64: - /* As above in the 32 bit case. */ - while (i<128) - { - png_uint_32 t = v++; - buffer[8*i+0] = (png_byte)((t >> 8) & 0xff); - buffer[8*i+1] = (png_byte)(t & 0xff); - buffer[8*i+4] = (png_byte)((t >> 8) & 0xff); - buffer[8*i+5] = (png_byte)(t & 0xff); - t *= 257; - buffer[8*i+2] = (png_byte)((t >> 8) & 0xff); - buffer[8*i+3] = (png_byte)(t & 0xff); - buffer[8*i+6] = (png_byte)((t >> 8) & 0xff); - buffer[8*i+7] = (png_byte)(t & 0xff); - ++i; - } - return; - - default: - break; - } - - png_error(pp, "internal error"); -} - -/* This is just to do the right cast - could be changed to a function to check - * 'bd' but there isn't much point. - */ -#define DEPTH(bd) ((png_byte)(1U << (bd))) - -/* This is just a helper for compiling on minimal systems with no write - * interlacing support. If there is no write interlacing we can't generate test - * cases with interlace: - */ -#ifdef PNG_WRITE_INTERLACING_SUPPORTED -# define INTERLACE_LAST PNG_INTERLACE_LAST -# define check_interlace_type(type) ((void)(type)) -#else -# define INTERLACE_LAST (PNG_INTERLACE_NONE+1) -# define png_set_interlace_handling(a) (1) - -static void -check_interlace_type(int PNG_CONST interlace_type) -{ - if (interlace_type != PNG_INTERLACE_NONE) - { - /* This is an internal error - --interlace tests should be skipped, not - * attempted. - */ - fprintf(stderr, "pngvalid: no interlace support\n"); - exit(99); - } -} -#endif - -/* Make a standardized image given a an image colour type, bit depth and - * interlace type. The standard images have a very restricted range of - * rows and heights and are used for testing transforms rather than image - * layout details. See make_size_images below for a way to make images - * that test odd sizes along with the libpng interlace handling. - */ -static void -make_transform_image(png_store* PNG_CONST ps, png_byte PNG_CONST colour_type, - png_byte PNG_CONST bit_depth, unsigned int palette_number, - int interlace_type, png_const_charp name) -{ - context(ps, fault); - - check_interlace_type(interlace_type); - - Try - { - png_infop pi; - png_structp pp = set_store_for_write(ps, &pi, name); - png_uint_32 h; - - /* In the event of a problem return control to the Catch statement below - * to do the clean up - it is not possible to 'return' directly from a Try - * block. - */ - if (pp == NULL) - Throw ps; - - h = transform_height(pp, colour_type, bit_depth); - - png_set_IHDR(pp, pi, transform_width(pp, colour_type, bit_depth), h, - bit_depth, colour_type, interlace_type, - PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE); - -#ifdef PNG_TEXT_SUPPORTED -# if defined(PNG_READ_zTXt_SUPPORTED) && defined(PNG_WRITE_zTXt_SUPPORTED) -# define TEXT_COMPRESSION PNG_TEXT_COMPRESSION_zTXt -# else -# define TEXT_COMPRESSION PNG_TEXT_COMPRESSION_NONE -# endif - { - static char key[] = "image name"; /* must be writeable */ - size_t pos; - png_text text; - char copy[FILE_NAME_SIZE]; - - /* Use a compressed text string to test the correct interaction of text - * compression and IDAT compression. - */ - text.compression = TEXT_COMPRESSION; - text.key = key; - /* Yuck: the text must be writable! */ - pos = safecat(copy, sizeof copy, 0, ps->wname); - text.text = copy; - text.text_length = pos; - text.itxt_length = 0; - text.lang = 0; - text.lang_key = 0; - - png_set_text(pp, pi, &text, 1); - } -#endif - - if (colour_type == 3) /* palette */ - init_standard_palette(ps, pp, pi, 1U << bit_depth, 1/*do tRNS*/); - - png_write_info(pp, pi); - - if (png_get_rowbytes(pp, pi) != - transform_rowsize(pp, colour_type, bit_depth)) - png_error(pp, "row size incorrect"); - - else - { - /* Somewhat confusingly this must be called *after* png_write_info - * because if it is called before, the information in *pp has not been - * updated to reflect the interlaced image. - */ - int npasses = png_set_interlace_handling(pp); - int pass; - - if (npasses != npasses_from_interlace_type(pp, interlace_type)) - png_error(pp, "write: png_set_interlace_handling failed"); - - for (pass=0; pass<npasses; ++pass) - { - png_uint_32 y; - - for (y=0; y<h; ++y) - { - png_byte buffer[TRANSFORM_ROWMAX]; - - transform_row(pp, buffer, colour_type, bit_depth, y); - png_write_row(pp, buffer); - } - } - } - -#ifdef PNG_TEXT_SUPPORTED - { - static char key[] = "end marker"; - static char comment[] = "end"; - png_text text; - - /* Use a compressed text string to test the correct interaction of text - * compression and IDAT compression. - */ - text.compression = TEXT_COMPRESSION; - text.key = key; - text.text = comment; - text.text_length = (sizeof comment)-1; - text.itxt_length = 0; - text.lang = 0; - text.lang_key = 0; - - png_set_text(pp, pi, &text, 1); - } -#endif - - png_write_end(pp, pi); - - /* And store this under the appropriate id, then clean up. */ - store_storefile(ps, FILEID(colour_type, bit_depth, palette_number, - interlace_type, 0, 0, 0)); - - store_write_reset(ps); - } - - Catch(fault) - { - /* Use the png_store returned by the exception. This may help the compiler - * because 'ps' is not used in this branch of the setjmp. Note that fault - * and ps will always be the same value. - */ - store_write_reset(fault); - } -} - -static void -make_transform_images(png_store *ps) -{ - png_byte colour_type = 0; - png_byte bit_depth = 0; - unsigned int palette_number = 0; - - /* This is in case of errors. */ - safecat(ps->test, sizeof ps->test, 0, "make standard images"); - - /* Use next_format to enumerate all the combinations we test, including - * generating multiple low bit depth palette images. - */ - while (next_format(&colour_type, &bit_depth, &palette_number, 0)) - { - int interlace_type; - - for (interlace_type = PNG_INTERLACE_NONE; - interlace_type < INTERLACE_LAST; ++interlace_type) - { - char name[FILE_NAME_SIZE]; - - standard_name(name, sizeof name, 0, colour_type, bit_depth, - palette_number, interlace_type, 0, 0, 0); - make_transform_image(ps, colour_type, bit_depth, palette_number, - interlace_type, name); - } - } -} - -/* The following two routines use the PNG interlace support macros from - * png.h to interlace or deinterlace rows. - */ -static void -interlace_row(png_bytep buffer, png_const_bytep imageRow, - unsigned int pixel_size, png_uint_32 w, int pass) -{ - png_uint_32 xin, xout, xstep; - - /* Note that this can, trivially, be optimized to a memcpy on pass 7, the - * code is presented this way to make it easier to understand. In practice - * consult the code in the libpng source to see other ways of doing this. - */ - xin = PNG_PASS_START_COL(pass); - xstep = 1U<<PNG_PASS_COL_SHIFT(pass); - - for (xout=0; xin<w; xin+=xstep) - { - pixel_copy(buffer, xout, imageRow, xin, pixel_size); - ++xout; - } -} - -#ifdef PNG_READ_SUPPORTED -static void -deinterlace_row(png_bytep buffer, png_const_bytep row, - unsigned int pixel_size, png_uint_32 w, int pass) -{ - /* The inverse of the above, 'row' is part of row 'y' of the output image, - * in 'buffer'. The image is 'w' wide and this is pass 'pass', distribute - * the pixels of row into buffer and return the number written (to allow - * this to be checked). - */ - png_uint_32 xin, xout, xstep; - - xout = PNG_PASS_START_COL(pass); - xstep = 1U<<PNG_PASS_COL_SHIFT(pass); - - for (xin=0; xout<w; xout+=xstep) - { - pixel_copy(buffer, xout, row, xin, pixel_size); - ++xin; - } -} -#endif /* PNG_READ_SUPPORTED */ - -/* Build a single row for the 'size' test images; this fills in only the - * first bit_width bits of the sample row. - */ -static void -size_row(png_byte buffer[SIZE_ROWMAX], png_uint_32 bit_width, png_uint_32 y) -{ - /* height is in the range 1 to 16, so: */ - y = ((y & 1) << 7) + ((y & 2) << 6) + ((y & 4) << 5) + ((y & 8) << 4); - /* the following ensures bits are set in small images: */ - y ^= 0xA5; - - while (bit_width >= 8) - *buffer++ = (png_byte)y++, bit_width -= 8; - - /* There may be up to 7 remaining bits, these go in the most significant - * bits of the byte. - */ - if (bit_width > 0) - { - png_uint_32 mask = (1U<<(8-bit_width))-1; - *buffer = (png_byte)((*buffer & mask) | (y & ~mask)); - } -} - -static void -make_size_image(png_store* PNG_CONST ps, png_byte PNG_CONST colour_type, - png_byte PNG_CONST bit_depth, int PNG_CONST interlace_type, - png_uint_32 PNG_CONST w, png_uint_32 PNG_CONST h, - int PNG_CONST do_interlace) -{ - context(ps, fault); - - /* At present libpng does not support the write of an interlaced image unless - * PNG_WRITE_INTERLACING_SUPPORTED, even with do_interlace so the code here - * does the pixel interlace itself, so: - */ - check_interlace_type(interlace_type); - - Try - { - png_infop pi; - png_structp pp; - unsigned int pixel_size; - - /* Make a name and get an appropriate id for the store: */ - char name[FILE_NAME_SIZE]; - PNG_CONST png_uint_32 id = FILEID(colour_type, bit_depth, 0/*palette*/, - interlace_type, w, h, do_interlace); - - standard_name_from_id(name, sizeof name, 0, id); - pp = set_store_for_write(ps, &pi, name); - - /* In the event of a problem return control to the Catch statement below - * to do the clean up - it is not possible to 'return' directly from a Try - * block. - */ - if (pp == NULL) - Throw ps; - - png_set_IHDR(pp, pi, w, h, bit_depth, colour_type, interlace_type, - PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE); - -#ifdef PNG_TEXT_SUPPORTED - { - static char key[] = "image name"; /* must be writeable */ - size_t pos; - png_text text; - char copy[FILE_NAME_SIZE]; - - /* Use a compressed text string to test the correct interaction of text - * compression and IDAT compression. - */ - text.compression = TEXT_COMPRESSION; - text.key = key; - /* Yuck: the text must be writable! */ - pos = safecat(copy, sizeof copy, 0, ps->wname); - text.text = copy; - text.text_length = pos; - text.itxt_length = 0; - text.lang = 0; - text.lang_key = 0; - - png_set_text(pp, pi, &text, 1); - } -#endif - - if (colour_type == 3) /* palette */ - init_standard_palette(ps, pp, pi, 1U << bit_depth, 0/*do tRNS*/); - - png_write_info(pp, pi); - - /* Calculate the bit size, divide by 8 to get the byte size - this won't - * overflow because we know the w values are all small enough even for - * a system where 'unsigned int' is only 16 bits. - */ - pixel_size = bit_size(pp, colour_type, bit_depth); - if (png_get_rowbytes(pp, pi) != ((w * pixel_size) + 7) / 8) - png_error(pp, "row size incorrect"); - - else - { - int npasses = npasses_from_interlace_type(pp, interlace_type); - png_uint_32 y; - int pass; -# ifdef PNG_WRITE_FILTER_SUPPORTED - int nfilter = PNG_FILTER_VALUE_LAST; -# endif - png_byte image[16][SIZE_ROWMAX]; - - /* To help consistent error detection make the parts of this buffer - * that aren't set below all '1': - */ - memset(image, 0xff, sizeof image); - - if (!do_interlace && npasses != png_set_interlace_handling(pp)) - png_error(pp, "write: png_set_interlace_handling failed"); - - /* Prepare the whole image first to avoid making it 7 times: */ - for (y=0; y<h; ++y) - size_row(image[y], w * pixel_size, y); - - for (pass=0; pass<npasses; ++pass) - { - /* The following two are for checking the macros: */ - PNG_CONST png_uint_32 wPass = PNG_PASS_COLS(w, pass); - - /* If do_interlace is set we don't call png_write_row for every - * row because some of them are empty. In fact, for a 1x1 image, - * most of them are empty! - */ - for (y=0; y<h; ++y) - { - png_const_bytep row = image[y]; - png_byte tempRow[SIZE_ROWMAX]; - - /* If do_interlace *and* the image is interlaced we - * need a reduced interlace row; this may be reduced - * to empty. - */ - if (do_interlace && interlace_type == PNG_INTERLACE_ADAM7) - { - /* The row must not be written if it doesn't exist, notice - * that there are two conditions here, either the row isn't - * ever in the pass or the row would be but isn't wide - * enough to contribute any pixels. In fact the wPass test - * can be used to skip the whole y loop in this case. - */ - if (PNG_ROW_IN_INTERLACE_PASS(y, pass) && wPass > 0) - { - /* Set to all 1's for error detection (libpng tends to - * set unset things to 0). - */ - memset(tempRow, 0xff, sizeof tempRow); - interlace_row(tempRow, row, pixel_size, w, pass); - row = tempRow; - } - else - continue; - } - -# ifdef PNG_WRITE_FILTER_SUPPORTED - /* Only get to here if the row has some pixels in it, set the - * filters to 'all' for the very first row and thereafter to a - * single filter. It isn't well documented, but png_set_filter - * does accept a filter number (per the spec) as well as a bit - * mask. - * - * The apparent wackiness of decrementing nfilter rather than - * incrementing is so that Paeth gets used in all images bigger - * than 1 row - it's the tricky one. - */ - png_set_filter(pp, 0/*method*/, - nfilter >= PNG_FILTER_VALUE_LAST ? PNG_ALL_FILTERS : nfilter); - - if (nfilter-- == 0) - nfilter = PNG_FILTER_VALUE_LAST-1; -# endif - - png_write_row(pp, row); - } - } - } - -#ifdef PNG_TEXT_SUPPORTED - { - static char key[] = "end marker"; - static char comment[] = "end"; - png_text text; - - /* Use a compressed text string to test the correct interaction of text - * compression and IDAT compression. - */ - text.compression = TEXT_COMPRESSION; - text.key = key; - text.text = comment; - text.text_length = (sizeof comment)-1; - text.itxt_length = 0; - text.lang = 0; - text.lang_key = 0; - - png_set_text(pp, pi, &text, 1); - } -#endif - - png_write_end(pp, pi); - - /* And store this under the appropriate id, then clean up. */ - store_storefile(ps, id); - - store_write_reset(ps); - } - - Catch(fault) - { - /* Use the png_store returned by the exception. This may help the compiler - * because 'ps' is not used in this branch of the setjmp. Note that fault - * and ps will always be the same value. - */ - store_write_reset(fault); - } -} - -static void -make_size(png_store* PNG_CONST ps, png_byte PNG_CONST colour_type, int bdlo, - int PNG_CONST bdhi) -{ - for (; bdlo <= bdhi; ++bdlo) - { - png_uint_32 width; - - for (width = 1; width <= 16; ++width) - { - png_uint_32 height; - - for (height = 1; height <= 16; ++height) - { - /* The four combinations of DIY interlace and interlace or not - - * no interlace + DIY should be identical to no interlace with - * libpng doing it. - */ - make_size_image(ps, colour_type, DEPTH(bdlo), PNG_INTERLACE_NONE, - width, height, 0); - make_size_image(ps, colour_type, DEPTH(bdlo), PNG_INTERLACE_NONE, - width, height, 1); -# ifdef PNG_WRITE_INTERLACING_SUPPORTED - make_size_image(ps, colour_type, DEPTH(bdlo), PNG_INTERLACE_ADAM7, - width, height, 0); - make_size_image(ps, colour_type, DEPTH(bdlo), PNG_INTERLACE_ADAM7, - width, height, 1); -# endif - } - } - } -} - -static void -make_size_images(png_store *ps) -{ - /* This is in case of errors. */ - safecat(ps->test, sizeof ps->test, 0, "make size images"); - - /* Arguments are colour_type, low bit depth, high bit depth - */ - make_size(ps, 0, 0, WRITE_BDHI); - make_size(ps, 2, 3, WRITE_BDHI); - make_size(ps, 3, 0, 3 /*palette: max 8 bits*/); - make_size(ps, 4, 3, WRITE_BDHI); - make_size(ps, 6, 3, WRITE_BDHI); -} - -#ifdef PNG_READ_SUPPORTED -/* Return a row based on image id and 'y' for checking: */ -static void -standard_row(png_const_structp pp, png_byte std[STANDARD_ROWMAX], - png_uint_32 id, png_uint_32 y) -{ - if (WIDTH_FROM_ID(id) == 0) - transform_row(pp, std, COL_FROM_ID(id), DEPTH_FROM_ID(id), y); - else - size_row(std, WIDTH_FROM_ID(id) * bit_size(pp, COL_FROM_ID(id), - DEPTH_FROM_ID(id)), y); -} -#endif /* PNG_READ_SUPPORTED */ - -/* Tests - individual test cases */ -/* Like 'make_standard' but errors are deliberately introduced into the calls - * to ensure that they get detected - it should not be possible to write an - * invalid image with libpng! - */ -/* TODO: the 'set' functions can probably all be made to take a - * png_const_structp rather than a modifiable one. - */ -#ifdef PNG_WARNINGS_SUPPORTED -static void -sBIT0_error_fn(png_structp pp, png_infop pi) -{ - /* 0 is invalid... */ - png_color_8 bad; - bad.red = bad.green = bad.blue = bad.gray = bad.alpha = 0; - png_set_sBIT(pp, pi, &bad); -} - -static void -sBIT_error_fn(png_structp pp, png_infop pi) -{ - png_byte bit_depth; - png_color_8 bad; - - if (png_get_color_type(pp, pi) == PNG_COLOR_TYPE_PALETTE) - bit_depth = 8; - - else - bit_depth = png_get_bit_depth(pp, pi); - - /* Now we know the bit depth we can easily generate an invalid sBIT entry */ - bad.red = bad.green = bad.blue = bad.gray = bad.alpha = - (png_byte)(bit_depth+1); - png_set_sBIT(pp, pi, &bad); -} - -static PNG_CONST struct -{ - void (*fn)(png_structp, png_infop); - PNG_CONST char *msg; - unsigned int warning :1; /* the error is a warning... */ -} error_test[] = - { - /* no warnings makes these errors undetectable. */ - { sBIT0_error_fn, "sBIT(0): failed to detect error", 1 }, - { sBIT_error_fn, "sBIT(too big): failed to detect error", 1 }, - }; - -static void -make_error(png_store* volatile psIn, png_byte PNG_CONST colour_type, - png_byte bit_depth, int interlace_type, int test, png_const_charp name) -{ - png_store * volatile ps = psIn; - - context(ps, fault); - - check_interlace_type(interlace_type); - - Try - { - png_structp pp; - png_infop pi; - - pp = set_store_for_write(ps, &pi, name); - - if (pp == NULL) - Throw ps; - - png_set_IHDR(pp, pi, transform_width(pp, colour_type, bit_depth), - transform_height(pp, colour_type, bit_depth), bit_depth, colour_type, - interlace_type, PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE); - - if (colour_type == 3) /* palette */ - init_standard_palette(ps, pp, pi, 1U << bit_depth, 0/*do tRNS*/); - - /* Time for a few errors; these are in various optional chunks, the - * standard tests test the standard chunks pretty well. - */ -# define exception__prev exception_prev_1 -# define exception__env exception_env_1 - Try - { - /* Expect this to throw: */ - ps->expect_error = !error_test[test].warning; - ps->expect_warning = error_test[test].warning; - ps->saw_warning = 0; - error_test[test].fn(pp, pi); - - /* Normally the error is only detected here: */ - png_write_info(pp, pi); - - /* And handle the case where it was only a warning: */ - if (ps->expect_warning && ps->saw_warning) - Throw ps; - - /* If we get here there is a problem, we have success - no error or - * no warning - when we shouldn't have success. Log an error. - */ - store_log(ps, pp, error_test[test].msg, 1 /*error*/); - } - - Catch (fault) - ps = fault; /* expected exit, make sure ps is not clobbered */ -#undef exception__prev -#undef exception__env - - /* And clear these flags */ - ps->expect_error = 0; - ps->expect_warning = 0; - - /* Now write the whole image, just to make sure that the detected, or - * undetected, errro has not created problems inside libpng. - */ - if (png_get_rowbytes(pp, pi) != - transform_rowsize(pp, colour_type, bit_depth)) - png_error(pp, "row size incorrect"); - - else - { - png_uint_32 h = transform_height(pp, colour_type, bit_depth); - int npasses = png_set_interlace_handling(pp); - int pass; - - if (npasses != npasses_from_interlace_type(pp, interlace_type)) - png_error(pp, "write: png_set_interlace_handling failed"); - - for (pass=0; pass<npasses; ++pass) - { - png_uint_32 y; - - for (y=0; y<h; ++y) - { - png_byte buffer[TRANSFORM_ROWMAX]; - - transform_row(pp, buffer, colour_type, bit_depth, y); - png_write_row(pp, buffer); - } - } - } - - png_write_end(pp, pi); - - /* The following deletes the file that was just written. */ - store_write_reset(ps); - } - - Catch(fault) - { - store_write_reset(fault); - } -} - -static int -make_errors(png_modifier* PNG_CONST pm, png_byte PNG_CONST colour_type, - int bdlo, int PNG_CONST bdhi) -{ - for (; bdlo <= bdhi; ++bdlo) - { - int interlace_type; - - for (interlace_type = PNG_INTERLACE_NONE; - interlace_type < INTERLACE_LAST; ++interlace_type) - { - unsigned int test; - char name[FILE_NAME_SIZE]; - - standard_name(name, sizeof name, 0, colour_type, 1<<bdlo, 0, - interlace_type, 0, 0, 0); - - for (test=0; test<ARRAY_SIZE(error_test); ++test) - { - make_error(&pm->this, colour_type, DEPTH(bdlo), interlace_type, - test, name); - - if (fail(pm)) - return 0; - } - } - } - - return 1; /* keep going */ -} -#endif /* PNG_WARNINGS_SUPPORTED */ - -static void -perform_error_test(png_modifier *pm) -{ -#ifdef PNG_WARNINGS_SUPPORTED /* else there are no cases that work! */ - /* Need to do this here because we just write in this test. */ - safecat(pm->this.test, sizeof pm->this.test, 0, "error test"); - - if (!make_errors(pm, 0, 0, WRITE_BDHI)) - return; - - if (!make_errors(pm, 2, 3, WRITE_BDHI)) - return; - - if (!make_errors(pm, 3, 0, 3)) - return; - - if (!make_errors(pm, 4, 3, WRITE_BDHI)) - return; - - if (!make_errors(pm, 6, 3, WRITE_BDHI)) - return; -#else - UNUSED(pm) -#endif -} - -/* This is just to validate the internal PNG formatting code - if this fails - * then the warning messages the library outputs will probably be garbage. - */ -static void -perform_formatting_test(png_store *volatile ps) -{ -#ifdef PNG_TIME_RFC1123_SUPPORTED - /* The handle into the formatting code is the RFC1123 support; this test does - * nothing if that is compiled out. - */ - context(ps, fault); - - Try - { - png_const_charp correct = "29 Aug 2079 13:53:60 +0000"; - png_const_charp result; -# if PNG_LIBPNG_VER >= 10600 - char timestring[29]; -# endif - png_structp pp; - png_time pt; - - pp = set_store_for_write(ps, NULL, "libpng formatting test"); - - if (pp == NULL) - Throw ps; - - - /* Arbitrary settings: */ - pt.year = 2079; - pt.month = 8; - pt.day = 29; - pt.hour = 13; - pt.minute = 53; - pt.second = 60; /* a leap second */ - -# if PNG_LIBPNG_VER < 10600 - result = png_convert_to_rfc1123(pp, &pt); -# else - if (png_convert_to_rfc1123_buffer(timestring, &pt)) - result = timestring; - - else - result = NULL; -# endif - - if (result == NULL) - png_error(pp, "png_convert_to_rfc1123 failed"); - - if (strcmp(result, correct) != 0) - { - size_t pos = 0; - char msg[128]; - - pos = safecat(msg, sizeof msg, pos, "png_convert_to_rfc1123("); - pos = safecat(msg, sizeof msg, pos, correct); - pos = safecat(msg, sizeof msg, pos, ") returned: '"); - pos = safecat(msg, sizeof msg, pos, result); - pos = safecat(msg, sizeof msg, pos, "'"); - - png_error(pp, msg); - } - - store_write_reset(ps); - } - - Catch(fault) - { - store_write_reset(fault); - } -#else - UNUSED(ps) -#endif -} - -#ifdef PNG_READ_SUPPORTED -/* Because we want to use the same code in both the progressive reader and the - * sequential reader it is necessary to deal with the fact that the progressive - * reader callbacks only have one parameter (png_get_progressive_ptr()), so this - * must contain all the test parameters and all the local variables directly - * accessible to the sequential reader implementation. - * - * The technique adopted is to reinvent part of what Dijkstra termed a - * 'display'; an array of pointers to the stack frames of enclosing functions so - * that a nested function definition can access the local (C auto) variables of - * the functions that contain its definition. In fact C provides the first - * pointer (the local variables - the stack frame pointer) and the last (the - * global variables - the BCPL global vector typically implemented as global - * addresses), this code requires one more pointer to make the display - the - * local variables (and function call parameters) of the function that actually - * invokes either the progressive or sequential reader. - * - * Perhaps confusingly this technique is confounded with classes - the - * 'standard_display' defined here is sub-classed as the 'gamma_display' below. - * A gamma_display is a standard_display, taking advantage of the ANSI-C - * requirement that the pointer to the first member of a structure must be the - * same as the pointer to the structure. This allows us to reuse standard_ - * functions in the gamma test code; something that could not be done with - * nested functions! - */ -typedef struct standard_display -{ - png_store* ps; /* Test parameters (passed to the function) */ - png_byte colour_type; - png_byte bit_depth; - png_byte red_sBIT; /* Input data sBIT values. */ - png_byte green_sBIT; - png_byte blue_sBIT; - png_byte alpha_sBIT; - png_byte interlace_type; - png_byte filler; /* Output has a filler */ - png_uint_32 id; /* Calculated file ID */ - png_uint_32 w; /* Width of image */ - png_uint_32 h; /* Height of image */ - int npasses; /* Number of interlaced passes */ - png_uint_32 pixel_size; /* Width of one pixel in bits */ - png_uint_32 bit_width; /* Width of output row in bits */ - size_t cbRow; /* Bytes in a row of the output image */ - int do_interlace; /* Do interlacing internally */ - int is_transparent; /* Transparency information was present. */ - int speed; /* Doing a speed test */ - int use_update_info;/* Call update_info, not start_image */ - struct - { - png_uint_16 red; - png_uint_16 green; - png_uint_16 blue; - } transparent; /* The transparent color, if set. */ - int npalette; /* Number of entries in the palette. */ - store_palette - palette; -} standard_display; - -static void -standard_display_init(standard_display *dp, png_store* ps, png_uint_32 id, - int do_interlace, int use_update_info) -{ - memset(dp, 0, sizeof *dp); - - dp->ps = ps; - dp->colour_type = COL_FROM_ID(id); - dp->bit_depth = DEPTH_FROM_ID(id); - if (dp->bit_depth < 1 || dp->bit_depth > 16) - internal_error(ps, "internal: bad bit depth"); - if (dp->colour_type == 3) - dp->red_sBIT = dp->blue_sBIT = dp->green_sBIT = dp->alpha_sBIT = 8; - else - dp->red_sBIT = dp->blue_sBIT = dp->green_sBIT = dp->alpha_sBIT = - dp->bit_depth; - dp->interlace_type = INTERLACE_FROM_ID(id); - check_interlace_type(dp->interlace_type); - dp->id = id; - /* All the rest are filled in after the read_info: */ - dp->w = 0; - dp->h = 0; - dp->npasses = 0; - dp->pixel_size = 0; - dp->bit_width = 0; - dp->cbRow = 0; - dp->do_interlace = do_interlace; - dp->is_transparent = 0; - dp->speed = ps->speed; - dp->use_update_info = use_update_info; - dp->npalette = 0; - /* Preset the transparent color to black: */ - memset(&dp->transparent, 0, sizeof dp->transparent); - /* Preset the palette to full intensity/opaque througout: */ - memset(dp->palette, 0xff, sizeof dp->palette); -} - -/* Initialize the palette fields - this must be done later because the palette - * comes from the particular png_store_file that is selected. - */ -static void -standard_palette_init(standard_display *dp) -{ - store_palette_entry *palette = store_current_palette(dp->ps, &dp->npalette); - - /* The remaining entries remain white/opaque. */ - if (dp->npalette > 0) - { - int i = dp->npalette; - memcpy(dp->palette, palette, i * sizeof *palette); - - /* Check for a non-opaque palette entry: */ - while (--i >= 0) - if (palette[i].alpha < 255) - break; - -# ifdef __GNUC__ - /* GCC can't handle the more obviously optimizable version. */ - if (i >= 0) - dp->is_transparent = 1; - else - dp->is_transparent = 0; -# else - dp->is_transparent = (i >= 0); -# endif - } -} - -/* Utility to read the palette from the PNG file and convert it into - * store_palette format. This returns 1 if there is any transparency in the - * palette (it does not check for a transparent colour in the non-palette case.) - */ -static int -read_palette(store_palette palette, int *npalette, png_const_structp pp, - png_infop pi) -{ - png_colorp pal; - png_bytep trans_alpha; - int num; - - pal = 0; - *npalette = -1; - - if (png_get_PLTE(pp, pi, &pal, npalette) & PNG_INFO_PLTE) - { - int i = *npalette; - - if (i <= 0 || i > 256) - png_error(pp, "validate: invalid PLTE count"); - - while (--i >= 0) - { - palette[i].red = pal[i].red; - palette[i].green = pal[i].green; - palette[i].blue = pal[i].blue; - } - - /* Mark the remainder of the entries with a flag value (other than - * white/opaque which is the flag value stored above.) - */ - memset(palette + *npalette, 126, (256-*npalette) * sizeof *palette); - } - - else /* !png_get_PLTE */ - { - if (*npalette != (-1)) - png_error(pp, "validate: invalid PLTE result"); - /* But there is no palette, so record this: */ - *npalette = 0; - memset(palette, 113, sizeof (store_palette)); - } - - trans_alpha = 0; - num = 2; /* force error below */ - if ((png_get_tRNS(pp, pi, &trans_alpha, &num, 0) & PNG_INFO_tRNS) != 0 && - (trans_alpha != NULL || num != 1/*returns 1 for a transparent color*/) && - /* Oops, if a palette tRNS gets expanded png_read_update_info (at least so - * far as 1.5.4) does not remove the trans_alpha pointer, only num_trans, - * so in the above call we get a success, we get a pointer (who knows what - * to) and we get num_trans == 0: - */ - !(trans_alpha != NULL && num == 0)) /* TODO: fix this in libpng. */ - { - int i; - - /* Any of these are crash-worthy - given the implementation of - * png_get_tRNS up to 1.5 an app won't crash if it just checks the - * result above and fails to check that the variables it passed have - * actually been filled in! Note that if the app were to pass the - * last, png_color_16p, variable too it couldn't rely on this. - */ - if (trans_alpha == NULL || num <= 0 || num > 256 || num > *npalette) - png_error(pp, "validate: unexpected png_get_tRNS (palette) result"); - - for (i=0; i<num; ++i) - palette[i].alpha = trans_alpha[i]; - - for (num=*npalette; i<num; ++i) - palette[i].alpha = 255; - - for (; i<256; ++i) - palette[i].alpha = 33; /* flag value */ - - return 1; /* transparency */ - } - - else - { - /* No palette transparency - just set the alpha channel to opaque. */ - int i; - - for (i=0, num=*npalette; i<num; ++i) - palette[i].alpha = 255; - - for (; i<256; ++i) - palette[i].alpha = 55; /* flag value */ - - return 0; /* no transparency */ - } -} - -/* Utility to validate the palette if it should not have changed (the - * non-transform case). - */ -static void -standard_palette_validate(standard_display *dp, png_const_structp pp, - png_infop pi) -{ - int npalette; - store_palette palette; - - if (read_palette(palette, &npalette, pp, pi) != dp->is_transparent) - png_error(pp, "validate: palette transparency changed"); - - if (npalette != dp->npalette) - { - size_t pos = 0; - char msg[64]; - - pos = safecat(msg, sizeof msg, pos, "validate: palette size changed: "); - pos = safecatn(msg, sizeof msg, pos, dp->npalette); - pos = safecat(msg, sizeof msg, pos, " -> "); - pos = safecatn(msg, sizeof msg, pos, npalette); - png_error(pp, msg); - } - - { - int i = npalette; /* npalette is aliased */ - - while (--i >= 0) - if (palette[i].red != dp->palette[i].red || - palette[i].green != dp->palette[i].green || - palette[i].blue != dp->palette[i].blue || - palette[i].alpha != dp->palette[i].alpha) - png_error(pp, "validate: PLTE or tRNS chunk changed"); - } -} - -/* By passing a 'standard_display' the progressive callbacks can be used - * directly by the sequential code, the functions suffixed "_imp" are the - * implementations, the functions without the suffix are the callbacks. - * - * The code for the info callback is split into two because this callback calls - * png_read_update_info or png_start_read_image and what gets called depends on - * whether the info needs updating (we want to test both calls in pngvalid.) - */ -static void -standard_info_part1(standard_display *dp, png_structp pp, png_infop pi) -{ - if (png_get_bit_depth(pp, pi) != dp->bit_depth) - png_error(pp, "validate: bit depth changed"); - - if (png_get_color_type(pp, pi) != dp->colour_type) - png_error(pp, "validate: color type changed"); - - if (png_get_filter_type(pp, pi) != PNG_FILTER_TYPE_BASE) - png_error(pp, "validate: filter type changed"); - - if (png_get_interlace_type(pp, pi) != dp->interlace_type) - png_error(pp, "validate: interlacing changed"); - - if (png_get_compression_type(pp, pi) != PNG_COMPRESSION_TYPE_BASE) - png_error(pp, "validate: compression type changed"); - - dp->w = png_get_image_width(pp, pi); - - if (dp->w != standard_width(pp, dp->id)) - png_error(pp, "validate: image width changed"); - - dp->h = png_get_image_height(pp, pi); - - if (dp->h != standard_height(pp, dp->id)) - png_error(pp, "validate: image height changed"); - - /* Record (but don't check at present) the input sBIT according to the colour - * type information. - */ - { - png_color_8p sBIT = 0; - - if (png_get_sBIT(pp, pi, &sBIT) & PNG_INFO_sBIT) - { - int sBIT_invalid = 0; - - if (sBIT == 0) - png_error(pp, "validate: unexpected png_get_sBIT result"); - - if (dp->colour_type & PNG_COLOR_MASK_COLOR) - { - if (sBIT->red == 0 || sBIT->red > dp->bit_depth) - sBIT_invalid = 1; - else - dp->red_sBIT = sBIT->red; - - if (sBIT->green == 0 || sBIT->green > dp->bit_depth) - sBIT_invalid = 1; - else - dp->green_sBIT = sBIT->green; - - if (sBIT->blue == 0 || sBIT->blue > dp->bit_depth) - sBIT_invalid = 1; - else - dp->blue_sBIT = sBIT->blue; - } - - else /* !COLOR */ - { - if (sBIT->gray == 0 || sBIT->gray > dp->bit_depth) - sBIT_invalid = 1; - else - dp->blue_sBIT = dp->green_sBIT = dp->red_sBIT = sBIT->gray; - } - - /* All 8 bits in tRNS for a palette image are significant - see the - * spec. - */ - if (dp->colour_type & PNG_COLOR_MASK_ALPHA) - { - if (sBIT->alpha == 0 || sBIT->alpha > dp->bit_depth) - sBIT_invalid = 1; - else - dp->alpha_sBIT = sBIT->alpha; - } - - if (sBIT_invalid) - png_error(pp, "validate: sBIT value out of range"); - } - } - - /* Important: this is validating the value *before* any transforms have been - * put in place. It doesn't matter for the standard tests, where there are - * no transforms, but it does for other tests where rowbytes may change after - * png_read_update_info. - */ - if (png_get_rowbytes(pp, pi) != standard_rowsize(pp, dp->id)) - png_error(pp, "validate: row size changed"); - - /* Validate the colour type 3 palette (this can be present on other color - * types.) - */ - standard_palette_validate(dp, pp, pi); - - /* In any case always check for a tranparent color (notice that the - * colour type 3 case must not give a successful return on the get_tRNS call - * with these arguments!) - */ - { - png_color_16p trans_color = 0; - - if (png_get_tRNS(pp, pi, 0, 0, &trans_color) & PNG_INFO_tRNS) - { - if (trans_color == 0) - png_error(pp, "validate: unexpected png_get_tRNS (color) result"); - - switch (dp->colour_type) - { - case 0: - dp->transparent.red = dp->transparent.green = dp->transparent.blue = - trans_color->gray; - dp->is_transparent = 1; - break; - - case 2: - dp->transparent.red = trans_color->red; - dp->transparent.green = trans_color->green; - dp->transparent.blue = trans_color->blue; - dp->is_transparent = 1; - break; - - case 3: - /* Not expected because it should result in the array case - * above. - */ - png_error(pp, "validate: unexpected png_get_tRNS result"); - break; - - default: - png_error(pp, "validate: invalid tRNS chunk with alpha image"); - } - } - } - - /* Read the number of passes - expected to match the value used when - * creating the image (interlaced or not). This has the side effect of - * turning on interlace handling (if do_interlace is not set.) - */ - dp->npasses = npasses_from_interlace_type(pp, dp->interlace_type); - if (!dp->do_interlace && dp->npasses != png_set_interlace_handling(pp)) - png_error(pp, "validate: file changed interlace type"); - - /* Caller calls png_read_update_info or png_start_read_image now, then calls - * part2. - */ -} - -/* This must be called *after* the png_read_update_info call to get the correct - * 'rowbytes' value, otherwise png_get_rowbytes will refer to the untransformed - * image. - */ -static void -standard_info_part2(standard_display *dp, png_const_structp pp, - png_const_infop pi, int nImages) -{ - /* Record cbRow now that it can be found. */ - { - png_byte ct = png_get_color_type(pp, pi); - png_byte bd = png_get_bit_depth(pp, pi); - - if (bd >= 8 && (ct == PNG_COLOR_TYPE_RGB || ct == PNG_COLOR_TYPE_GRAY) && - dp->filler) - ct |= 4; /* handle filler as faked alpha channel */ - - dp->pixel_size = bit_size(pp, ct, bd); - } - dp->bit_width = png_get_image_width(pp, pi) * dp->pixel_size; - dp->cbRow = png_get_rowbytes(pp, pi); - - /* Validate the rowbytes here again. */ - if (dp->cbRow != (dp->bit_width+7)/8) - png_error(pp, "bad png_get_rowbytes calculation"); - - /* Then ensure there is enough space for the output image(s). */ - store_ensure_image(dp->ps, pp, nImages, dp->cbRow, dp->h); -} - -static void -standard_info_imp(standard_display *dp, png_structp pp, png_infop pi, - int nImages) -{ - /* Note that the validation routine has the side effect of turning on - * interlace handling in the subsequent code. - */ - standard_info_part1(dp, pp, pi); - - /* And the info callback has to call this (or png_read_update_info - see - * below in the png_modifier code for that variant. - */ - if (dp->use_update_info) - { - /* For debugging the effect of multiple calls: */ - int i = dp->use_update_info; - while (i-- > 0) - png_read_update_info(pp, pi); - } - - else - png_start_read_image(pp); - - /* Validate the height, width and rowbytes plus ensure that sufficient buffer - * exists for decoding the image. - */ - standard_info_part2(dp, pp, pi, nImages); -} - -static void PNGCBAPI -standard_info(png_structp pp, png_infop pi) -{ - standard_display *dp = voidcast(standard_display*, - png_get_progressive_ptr(pp)); - - /* Call with nImages==1 because the progressive reader can only produce one - * image. - */ - standard_info_imp(dp, pp, pi, 1 /*only one image*/); -} - -static void PNGCBAPI -progressive_row(png_structp ppIn, png_bytep new_row, png_uint_32 y, int pass) -{ - png_const_structp pp = ppIn; - PNG_CONST standard_display *dp = voidcast(standard_display*, - png_get_progressive_ptr(pp)); - - /* When handling interlacing some rows will be absent in each pass, the - * callback still gets called, but with a NULL pointer. This is checked - * in the 'else' clause below. We need our own 'cbRow', but we can't call - * png_get_rowbytes because we got no info structure. - */ - if (new_row != NULL) - { - png_bytep row; - - /* In the case where the reader doesn't do the interlace it gives - * us the y in the sub-image: - */ - if (dp->do_interlace && dp->interlace_type == PNG_INTERLACE_ADAM7) - { -#ifdef PNG_USER_TRANSFORM_INFO_SUPPORTED - /* Use this opportunity to validate the png 'current' APIs: */ - if (y != png_get_current_row_number(pp)) - png_error(pp, "png_get_current_row_number is broken"); - - if (pass != png_get_current_pass_number(pp)) - png_error(pp, "png_get_current_pass_number is broken"); -#endif - - y = PNG_ROW_FROM_PASS_ROW(y, pass); - } - - /* Validate this just in case. */ - if (y >= dp->h) - png_error(pp, "invalid y to progressive row callback"); - - row = store_image_row(dp->ps, pp, 0, y); - -#ifdef PNG_READ_INTERLACING_SUPPORTED - /* Combine the new row into the old: */ - if (dp->do_interlace) - { - if (dp->interlace_type == PNG_INTERLACE_ADAM7) - deinterlace_row(row, new_row, dp->pixel_size, dp->w, pass); - else - row_copy(row, new_row, dp->pixel_size * dp->w); - } - else - png_progressive_combine_row(pp, row, new_row); -#endif /* PNG_READ_INTERLACING_SUPPORTED */ - } - -#ifdef PNG_READ_INTERLACING_SUPPORTED - else if (dp->interlace_type == PNG_INTERLACE_ADAM7 && - PNG_ROW_IN_INTERLACE_PASS(y, pass) && - PNG_PASS_COLS(dp->w, pass) > 0) - png_error(pp, "missing row in progressive de-interlacing"); -#endif /* PNG_READ_INTERLACING_SUPPORTED */ -} - -static void -sequential_row(standard_display *dp, png_structp pp, png_infop pi, - PNG_CONST int iImage, PNG_CONST int iDisplay) -{ - PNG_CONST int npasses = dp->npasses; - PNG_CONST int do_interlace = dp->do_interlace && - dp->interlace_type == PNG_INTERLACE_ADAM7; - PNG_CONST png_uint_32 height = standard_height(pp, dp->id); - PNG_CONST png_uint_32 width = standard_width(pp, dp->id); - PNG_CONST png_store* ps = dp->ps; - int pass; - - for (pass=0; pass<npasses; ++pass) - { - png_uint_32 y; - png_uint_32 wPass = PNG_PASS_COLS(width, pass); - - for (y=0; y<height; ++y) - { - if (do_interlace) - { - /* wPass may be zero or this row may not be in this pass. - * png_read_row must not be called in either case. - */ - if (wPass > 0 && PNG_ROW_IN_INTERLACE_PASS(y, pass)) - { - /* Read the row into a pair of temporary buffers, then do the - * merge here into the output rows. - */ - png_byte row[STANDARD_ROWMAX], display[STANDARD_ROWMAX]; - - /* The following aids (to some extent) error detection - we can - * see where png_read_row wrote. Use opposite values in row and - * display to make this easier. Don't use 0xff (which is used in - * the image write code to fill unused bits) or 0 (which is a - * likely value to overwrite unused bits with). - */ - memset(row, 0xc5, sizeof row); - memset(display, 0x5c, sizeof display); - - png_read_row(pp, row, display); - - if (iImage >= 0) - deinterlace_row(store_image_row(ps, pp, iImage, y), row, - dp->pixel_size, dp->w, pass); - - if (iDisplay >= 0) - deinterlace_row(store_image_row(ps, pp, iDisplay, y), display, - dp->pixel_size, dp->w, pass); - } - } - else - png_read_row(pp, - iImage >= 0 ? store_image_row(ps, pp, iImage, y) : NULL, - iDisplay >= 0 ? store_image_row(ps, pp, iDisplay, y) : NULL); - } - } - - /* And finish the read operation (only really necessary if the caller wants - * to find additional data in png_info from chunks after the last IDAT.) - */ - png_read_end(pp, pi); -} - -#ifdef PNG_TEXT_SUPPORTED -static void -standard_check_text(png_const_structp pp, png_const_textp tp, - png_const_charp keyword, png_const_charp text) -{ - char msg[1024]; - size_t pos = safecat(msg, sizeof msg, 0, "text: "); - size_t ok; - - pos = safecat(msg, sizeof msg, pos, keyword); - pos = safecat(msg, sizeof msg, pos, ": "); - ok = pos; - - if (tp->compression != TEXT_COMPRESSION) - { - char buf[64]; - - sprintf(buf, "compression [%d->%d], ", TEXT_COMPRESSION, - tp->compression); - pos = safecat(msg, sizeof msg, pos, buf); - } - - if (tp->key == NULL || strcmp(tp->key, keyword) != 0) - { - pos = safecat(msg, sizeof msg, pos, "keyword \""); - if (tp->key != NULL) - { - pos = safecat(msg, sizeof msg, pos, tp->key); - pos = safecat(msg, sizeof msg, pos, "\", "); - } - - else - pos = safecat(msg, sizeof msg, pos, "null, "); - } - - if (tp->text == NULL) - pos = safecat(msg, sizeof msg, pos, "text lost, "); - - else - { - if (tp->text_length != strlen(text)) - { - char buf[64]; - sprintf(buf, "text length changed[%lu->%lu], ", - (unsigned long)strlen(text), (unsigned long)tp->text_length); - pos = safecat(msg, sizeof msg, pos, buf); - } - - if (strcmp(tp->text, text) != 0) - { - pos = safecat(msg, sizeof msg, pos, "text becomes \""); - pos = safecat(msg, sizeof msg, pos, tp->text); - pos = safecat(msg, sizeof msg, pos, "\" (was \""); - pos = safecat(msg, sizeof msg, pos, text); - pos = safecat(msg, sizeof msg, pos, "\"), "); - } - } - - if (tp->itxt_length != 0) - pos = safecat(msg, sizeof msg, pos, "iTXt length set, "); - - if (tp->lang != NULL) - { - pos = safecat(msg, sizeof msg, pos, "iTXt language \""); - pos = safecat(msg, sizeof msg, pos, tp->lang); - pos = safecat(msg, sizeof msg, pos, "\", "); - } - - if (tp->lang_key != NULL) - { - pos = safecat(msg, sizeof msg, pos, "iTXt keyword \""); - pos = safecat(msg, sizeof msg, pos, tp->lang_key); - pos = safecat(msg, sizeof msg, pos, "\", "); - } - - if (pos > ok) - { - msg[pos-2] = '\0'; /* Remove the ", " at the end */ - png_error(pp, msg); - } -} - -static void -standard_text_validate(standard_display *dp, png_const_structp pp, - png_infop pi, int check_end) -{ - png_textp tp = NULL; - png_uint_32 num_text = png_get_text(pp, pi, &tp, NULL); - - if (num_text == 2 && tp != NULL) - { - standard_check_text(pp, tp, "image name", dp->ps->current->name); - - /* This exists because prior to 1.5.18 the progressive reader left the - * png_struct z_stream unreset at the end of the image, so subsequent - * attempts to use it simply returns Z_STREAM_END. - */ - if (check_end) - standard_check_text(pp, tp+1, "end marker", "end"); - } - - else - { - char msg[64]; - - sprintf(msg, "expected two text items, got %lu", - (unsigned long)num_text); - png_error(pp, msg); - } -} -#else -# define standard_text_validate(dp,pp,pi,check_end) ((void)0) -#endif - -static void -standard_row_validate(standard_display *dp, png_const_structp pp, - int iImage, int iDisplay, png_uint_32 y) -{ - int where; - png_byte std[STANDARD_ROWMAX]; - - /* The row must be pre-initialized to the magic number here for the size - * tests to pass: - */ - memset(std, 178, sizeof std); - standard_row(pp, std, dp->id, y); - - /* At the end both the 'row' and 'display' arrays should end up identical. - * In earlier passes 'row' will be partially filled in, with only the pixels - * that have been read so far, but 'display' will have those pixels - * replicated to fill the unread pixels while reading an interlaced image. -#if PNG_LIBPNG_VER < 10506 - * The side effect inside the libpng sequential reader is that the 'row' - * array retains the correct values for unwritten pixels within the row - * bytes, while the 'display' array gets bits off the end of the image (in - * the last byte) trashed. Unfortunately in the progressive reader the - * row bytes are always trashed, so we always do a pixel_cmp here even though - * a memcmp of all cbRow bytes will succeed for the sequential reader. -#endif - */ - if (iImage >= 0 && - (where = pixel_cmp(std, store_image_row(dp->ps, pp, iImage, y), - dp->bit_width)) != 0) - { - char msg[64]; - sprintf(msg, "PNG image row[%lu][%d] changed from %.2x to %.2x", - (unsigned long)y, where-1, std[where-1], - store_image_row(dp->ps, pp, iImage, y)[where-1]); - png_error(pp, msg); - } - -#if PNG_LIBPNG_VER < 10506 - /* In this case use pixel_cmp because we need to compare a partial - * byte at the end of the row if the row is not an exact multiple - * of 8 bits wide. (This is fixed in libpng-1.5.6 and pixel_cmp is - * changed to match!) - */ -#endif - if (iDisplay >= 0 && - (where = pixel_cmp(std, store_image_row(dp->ps, pp, iDisplay, y), - dp->bit_width)) != 0) - { - char msg[64]; - sprintf(msg, "display row[%lu][%d] changed from %.2x to %.2x", - (unsigned long)y, where-1, std[where-1], - store_image_row(dp->ps, pp, iDisplay, y)[where-1]); - png_error(pp, msg); - } -} - -static void -standard_image_validate(standard_display *dp, png_const_structp pp, int iImage, - int iDisplay) -{ - png_uint_32 y; - - if (iImage >= 0) - store_image_check(dp->ps, pp, iImage); - - if (iDisplay >= 0) - store_image_check(dp->ps, pp, iDisplay); - - for (y=0; y<dp->h; ++y) - standard_row_validate(dp, pp, iImage, iDisplay, y); - - /* This avoids false positives if the validation code is never called! */ - dp->ps->validated = 1; -} - -static void PNGCBAPI -standard_end(png_structp ppIn, png_infop pi) -{ - png_const_structp pp = ppIn; - standard_display *dp = voidcast(standard_display*, - png_get_progressive_ptr(pp)); - - UNUSED(pi) - - /* Validate the image - progressive reading only produces one variant for - * interlaced images. - */ - standard_text_validate(dp, pp, pi, - PNG_LIBPNG_VER >= 10518/*check_end: see comments above*/); - standard_image_validate(dp, pp, 0, -1); -} - -/* A single test run checking the standard image to ensure it is not damaged. */ -static void -standard_test(png_store* PNG_CONST psIn, png_uint_32 PNG_CONST id, - int do_interlace, int use_update_info) -{ - standard_display d; - context(psIn, fault); - - /* Set up the display (stack frame) variables from the arguments to the - * function and initialize the locals that are filled in later. - */ - standard_display_init(&d, psIn, id, do_interlace, use_update_info); - - /* Everything is protected by a Try/Catch. The functions called also - * typically have local Try/Catch blocks. - */ - Try - { - png_structp pp; - png_infop pi; - - /* Get a png_struct for reading the image. This will throw an error if it - * fails, so we don't need to check the result. - */ - pp = set_store_for_read(d.ps, &pi, d.id, - d.do_interlace ? (d.ps->progressive ? - "pngvalid progressive deinterlacer" : - "pngvalid sequential deinterlacer") : (d.ps->progressive ? - "progressive reader" : "sequential reader")); - - /* Initialize the palette correctly from the png_store_file. */ - standard_palette_init(&d); - - /* Introduce the correct read function. */ - if (d.ps->progressive) - { - png_set_progressive_read_fn(pp, &d, standard_info, progressive_row, - standard_end); - - /* Now feed data into the reader until we reach the end: */ - store_progressive_read(d.ps, pp, pi); - } - else - { - /* Note that this takes the store, not the display. */ - png_set_read_fn(pp, d.ps, store_read); - - /* Check the header values: */ - png_read_info(pp, pi); - - /* The code tests both versions of the images that the sequential - * reader can produce. - */ - standard_info_imp(&d, pp, pi, 2 /*images*/); - - /* Need the total bytes in the image below; we can't get to this point - * unless the PNG file values have been checked against the expected - * values. - */ - { - sequential_row(&d, pp, pi, 0, 1); - - /* After the last pass loop over the rows again to check that the - * image is correct. - */ - if (!d.speed) - { - standard_text_validate(&d, pp, pi, 1/*check_end*/); - standard_image_validate(&d, pp, 0, 1); - } - else - d.ps->validated = 1; - } - } - - /* Check for validation. */ - if (!d.ps->validated) - png_error(pp, "image read failed silently"); - - /* Successful completion. */ - } - - Catch(fault) - d.ps = fault; /* make sure this hasn't been clobbered. */ - - /* In either case clean up the store. */ - store_read_reset(d.ps); -} - -static int -test_standard(png_modifier* PNG_CONST pm, png_byte PNG_CONST colour_type, - int bdlo, int PNG_CONST bdhi) -{ - for (; bdlo <= bdhi; ++bdlo) - { - int interlace_type; - - for (interlace_type = PNG_INTERLACE_NONE; - interlace_type < INTERLACE_LAST; ++interlace_type) - { - standard_test(&pm->this, FILEID(colour_type, DEPTH(bdlo), 0/*palette*/, - interlace_type, 0, 0, 0), 0/*do_interlace*/, pm->use_update_info); - - if (fail(pm)) - return 0; - } - } - - return 1; /* keep going */ -} - -static void -perform_standard_test(png_modifier *pm) -{ - /* Test each colour type over the valid range of bit depths (expressed as - * log2(bit_depth) in turn, stop as soon as any error is detected. - */ - if (!test_standard(pm, 0, 0, READ_BDHI)) - return; - - if (!test_standard(pm, 2, 3, READ_BDHI)) - return; - - if (!test_standard(pm, 3, 0, 3)) - return; - - if (!test_standard(pm, 4, 3, READ_BDHI)) - return; - - if (!test_standard(pm, 6, 3, READ_BDHI)) - return; -} - - -/********************************** SIZE TESTS ********************************/ -static int -test_size(png_modifier* PNG_CONST pm, png_byte PNG_CONST colour_type, - int bdlo, int PNG_CONST bdhi) -{ - /* Run the tests on each combination. - * - * NOTE: on my 32 bit x86 each of the following blocks takes - * a total of 3.5 seconds if done across every combo of bit depth - * width and height. This is a waste of time in practice, hence the - * hinc and winc stuff: - */ - static PNG_CONST png_byte hinc[] = {1, 3, 11, 1, 5}; - static PNG_CONST png_byte winc[] = {1, 9, 5, 7, 1}; - for (; bdlo <= bdhi; ++bdlo) - { - png_uint_32 h, w; - - for (h=1; h<=16; h+=hinc[bdlo]) for (w=1; w<=16; w+=winc[bdlo]) - { - /* First test all the 'size' images against the sequential - * reader using libpng to deinterlace (where required.) This - * validates the write side of libpng. There are four possibilities - * to validate. - */ - standard_test(&pm->this, FILEID(colour_type, DEPTH(bdlo), 0/*palette*/, - PNG_INTERLACE_NONE, w, h, 0), 0/*do_interlace*/, - pm->use_update_info); - - if (fail(pm)) - return 0; - - standard_test(&pm->this, FILEID(colour_type, DEPTH(bdlo), 0/*palette*/, - PNG_INTERLACE_NONE, w, h, 1), 0/*do_interlace*/, - pm->use_update_info); - - if (fail(pm)) - return 0; - -# ifdef PNG_WRITE_INTERLACING_SUPPORTED - standard_test(&pm->this, FILEID(colour_type, DEPTH(bdlo), 0/*palette*/, - PNG_INTERLACE_ADAM7, w, h, 0), 0/*do_interlace*/, - pm->use_update_info); - - if (fail(pm)) - return 0; - - standard_test(&pm->this, FILEID(colour_type, DEPTH(bdlo), 0/*palette*/, - PNG_INTERLACE_ADAM7, w, h, 1), 0/*do_interlace*/, - pm->use_update_info); - - if (fail(pm)) - return 0; -# endif - - /* Now validate the interlaced read side - do_interlace true, - * in the progressive case this does actually make a difference - * to the code used in the non-interlaced case too. - */ - standard_test(&pm->this, FILEID(colour_type, DEPTH(bdlo), 0/*palette*/, - PNG_INTERLACE_NONE, w, h, 0), 1/*do_interlace*/, - pm->use_update_info); - - if (fail(pm)) - return 0; - -# ifdef PNG_WRITE_INTERLACING_SUPPORTED - standard_test(&pm->this, FILEID(colour_type, DEPTH(bdlo), 0/*palette*/, - PNG_INTERLACE_ADAM7, w, h, 0), 1/*do_interlace*/, - pm->use_update_info); - - if (fail(pm)) - return 0; -# endif - } - } - - return 1; /* keep going */ -} - -static void -perform_size_test(png_modifier *pm) -{ - /* Test each colour type over the valid range of bit depths (expressed as - * log2(bit_depth) in turn, stop as soon as any error is detected. - */ - if (!test_size(pm, 0, 0, READ_BDHI)) - return; - - if (!test_size(pm, 2, 3, READ_BDHI)) - return; - - /* For the moment don't do the palette test - it's a waste of time when - * compared to the grayscale test. - */ -#if 0 - if (!test_size(pm, 3, 0, 3)) - return; -#endif - - if (!test_size(pm, 4, 3, READ_BDHI)) - return; - - if (!test_size(pm, 6, 3, READ_BDHI)) - return; -} - - -/******************************* TRANSFORM TESTS ******************************/ -#ifdef PNG_READ_TRANSFORMS_SUPPORTED -/* A set of tests to validate libpng image transforms. The possibilities here - * are legion because the transforms can be combined in a combinatorial - * fashion. To deal with this some measure of restraint is required, otherwise - * the tests would take forever. - */ -typedef struct image_pixel -{ - /* A local (pngvalid) representation of a PNG pixel, in all its - * various forms. - */ - unsigned int red, green, blue, alpha; /* For non-palette images. */ - unsigned int palette_index; /* For a palette image. */ - png_byte colour_type; /* As in the spec. */ - png_byte bit_depth; /* Defines bit size in row */ - png_byte sample_depth; /* Scale of samples */ - unsigned int have_tRNS :1; /* tRNS chunk may need processing */ - unsigned int swap_rgb :1; /* RGB swapped to BGR */ - unsigned int alpha_first :1; /* Alpha at start, not end */ - unsigned int alpha_inverted :1; /* Alpha channel inverted */ - unsigned int mono_inverted :1; /* Gray channel inverted */ - unsigned int swap16 :1; /* Byte swap 16-bit components */ - unsigned int littleendian :1; /* High bits on right */ - unsigned int sig_bits :1; /* Pixel shifted (sig bits only) */ - - /* For checking the code calculates double precision floating point values - * along with an error value, accumulated from the transforms. Because an - * sBIT setting allows larger error bounds (indeed, by the spec, apparently - * up to just less than +/-1 in the scaled value) the *lowest* sBIT for each - * channel is stored. This sBIT value is folded in to the stored error value - * at the end of the application of the transforms to the pixel. - * - * If sig_bits is set above the red, green, blue and alpha values have been - * scaled so they only contain the significant bits of the component values. - */ - double redf, greenf, bluef, alphaf; - double rede, greene, bluee, alphae; - png_byte red_sBIT, green_sBIT, blue_sBIT, alpha_sBIT; -} image_pixel; - -/* Shared utility function, see below. */ -static void -image_pixel_setf(image_pixel *this, unsigned int rMax, unsigned int gMax, - unsigned int bMax, unsigned int aMax) -{ - this->redf = this->red / (double)rMax; - this->greenf = this->green / (double)gMax; - this->bluef = this->blue / (double)bMax; - this->alphaf = this->alpha / (double)aMax; - - if (this->red < rMax) - this->rede = this->redf * DBL_EPSILON; - else - this->rede = 0; - if (this->green < gMax) - this->greene = this->greenf * DBL_EPSILON; - else - this->greene = 0; - if (this->blue < bMax) - this->bluee = this->bluef * DBL_EPSILON; - else - this->bluee = 0; - if (this->alpha < aMax) - this->alphae = this->alphaf * DBL_EPSILON; - else - this->alphae = 0; -} - -/* Initialize the structure for the next pixel - call this before doing any - * transforms and call it for each pixel since all the fields may need to be - * reset. - */ -static void -image_pixel_init(image_pixel *this, png_const_bytep row, png_byte colour_type, - png_byte bit_depth, png_uint_32 x, store_palette palette, - PNG_CONST image_pixel *format /*from pngvalid transform of input*/) -{ - PNG_CONST png_byte sample_depth = (png_byte)(colour_type == - PNG_COLOR_TYPE_PALETTE ? 8 : bit_depth); - PNG_CONST unsigned int max = (1U<<sample_depth)-1; - PNG_CONST int swap16 = (format != 0 && format->swap16); - PNG_CONST int littleendian = (format != 0 && format->littleendian); - PNG_CONST int sig_bits = (format != 0 && format->sig_bits); - - /* Initially just set everything to the same number and the alpha to opaque. - * Note that this currently assumes a simple palette where entry x has colour - * rgb(x,x,x)! - */ - this->palette_index = this->red = this->green = this->blue = - sample(row, colour_type, bit_depth, x, 0, swap16, littleendian); - this->alpha = max; - this->red_sBIT = this->green_sBIT = this->blue_sBIT = this->alpha_sBIT = - sample_depth; - - /* Then override as appropriate: */ - if (colour_type == 3) /* palette */ - { - /* This permits the caller to default to the sample value. */ - if (palette != 0) - { - PNG_CONST unsigned int i = this->palette_index; - - this->red = palette[i].red; - this->green = palette[i].green; - this->blue = palette[i].blue; - this->alpha = palette[i].alpha; - } - } - - else /* not palette */ - { - unsigned int i = 0; - - if ((colour_type & 4) != 0 && format != 0 && format->alpha_first) - { - this->alpha = this->red; - /* This handles the gray case for 'AG' pixels */ - this->palette_index = this->red = this->green = this->blue = - sample(row, colour_type, bit_depth, x, 1, swap16, littleendian); - i = 1; - } - - if (colour_type & 2) - { - /* Green is second for both BGR and RGB: */ - this->green = sample(row, colour_type, bit_depth, x, ++i, swap16, - littleendian); - - if (format != 0 && format->swap_rgb) /* BGR */ - this->red = sample(row, colour_type, bit_depth, x, ++i, swap16, - littleendian); - else - this->blue = sample(row, colour_type, bit_depth, x, ++i, swap16, - littleendian); - } - - else /* grayscale */ if (format != 0 && format->mono_inverted) - this->red = this->green = this->blue = this->red ^ max; - - if ((colour_type & 4) != 0) /* alpha */ - { - if (format == 0 || !format->alpha_first) - this->alpha = sample(row, colour_type, bit_depth, x, ++i, swap16, - littleendian); - - if (format != 0 && format->alpha_inverted) - this->alpha ^= max; - } - } - - /* Calculate the scaled values, these are simply the values divided by - * 'max' and the error is initialized to the double precision epsilon value - * from the header file. - */ - image_pixel_setf(this, - sig_bits ? (1U << format->red_sBIT)-1 : max, - sig_bits ? (1U << format->green_sBIT)-1 : max, - sig_bits ? (1U << format->blue_sBIT)-1 : max, - sig_bits ? (1U << format->alpha_sBIT)-1 : max); - - /* Store the input information for use in the transforms - these will - * modify the information. - */ - this->colour_type = colour_type; - this->bit_depth = bit_depth; - this->sample_depth = sample_depth; - this->have_tRNS = 0; - this->swap_rgb = 0; - this->alpha_first = 0; - this->alpha_inverted = 0; - this->mono_inverted = 0; - this->swap16 = 0; - this->littleendian = 0; - this->sig_bits = 0; -} - -/* Convert a palette image to an rgb image. This necessarily converts the tRNS - * chunk at the same time, because the tRNS will be in palette form. The way - * palette validation works means that the original palette is never updated, - * instead the image_pixel value from the row contains the RGB of the - * corresponding palette entry and *this* is updated. Consequently this routine - * only needs to change the colour type information. - */ -static void -image_pixel_convert_PLTE(image_pixel *this) -{ - if (this->colour_type == PNG_COLOR_TYPE_PALETTE) - { - if (this->have_tRNS) - { - this->colour_type = PNG_COLOR_TYPE_RGB_ALPHA; - this->have_tRNS = 0; - } - else - this->colour_type = PNG_COLOR_TYPE_RGB; - - /* The bit depth of the row changes at this point too (notice that this is - * the row format, not the sample depth, which is separate.) - */ - this->bit_depth = 8; - } -} - -/* Add an alpha channel; this will import the tRNS information because tRNS is - * not valid in an alpha image. The bit depth will invariably be set to at - * least 8. Palette images will be converted to alpha (using the above API). - */ -static void -image_pixel_add_alpha(image_pixel *this, PNG_CONST standard_display *display) -{ - if (this->colour_type == PNG_COLOR_TYPE_PALETTE) - image_pixel_convert_PLTE(this); - - if ((this->colour_type & PNG_COLOR_MASK_ALPHA) == 0) - { - if (this->colour_type == PNG_COLOR_TYPE_GRAY) - { - if (this->bit_depth < 8) - this->bit_depth = 8; - - if (this->have_tRNS) - { - this->have_tRNS = 0; - - /* Check the input, original, channel value here against the - * original tRNS gray chunk valie. - */ - if (this->red == display->transparent.red) - this->alphaf = 0; - else - this->alphaf = 1; - } - else - this->alphaf = 1; - - this->colour_type = PNG_COLOR_TYPE_GRAY_ALPHA; - } - - else if (this->colour_type == PNG_COLOR_TYPE_RGB) - { - if (this->have_tRNS) - { - this->have_tRNS = 0; - - /* Again, check the exact input values, not the current transformed - * value! - */ - if (this->red == display->transparent.red && - this->green == display->transparent.green && - this->blue == display->transparent.blue) - this->alphaf = 0; - else - this->alphaf = 1; - - this->colour_type = PNG_COLOR_TYPE_RGB_ALPHA; - } - } - - /* The error in the alpha is zero and the sBIT value comes from the - * original sBIT data (actually it will always be the original bit depth). - */ - this->alphae = 0; - this->alpha_sBIT = display->alpha_sBIT; - } -} - -struct transform_display; -typedef struct image_transform -{ - /* The name of this transform: a string. */ - PNG_CONST char *name; - - /* Each transform can be disabled from the command line: */ - int enable; - - /* The global list of transforms; read only. */ - struct image_transform *PNG_CONST list; - - /* The global count of the number of times this transform has been set on an - * image. - */ - unsigned int global_use; - - /* The local count of the number of times this transform has been set. */ - unsigned int local_use; - - /* The next transform in the list, each transform must call its own next - * transform after it has processed the pixel successfully. - */ - PNG_CONST struct image_transform *next; - - /* A single transform for the image, expressed as a series of function - * callbacks and some space for values. - * - * First a callback to add any required modifications to the png_modifier; - * this gets called just before the modifier is set up for read. - */ - void (*ini)(PNG_CONST struct image_transform *this, - struct transform_display *that); - - /* And a callback to set the transform on the current png_read_struct: - */ - void (*set)(PNG_CONST struct image_transform *this, - struct transform_display *that, png_structp pp, png_infop pi); - - /* Then a transform that takes an input pixel in one PNG format or another - * and modifies it by a pngvalid implementation of the transform (thus - * duplicating the libpng intent without, we hope, duplicating the bugs - * in the libpng implementation!) The png_structp is solely to allow error - * reporting via png_error and png_warning. - */ - void (*mod)(PNG_CONST struct image_transform *this, image_pixel *that, - png_const_structp pp, PNG_CONST struct transform_display *display); - - /* Add this transform to the list and return true if the transform is - * meaningful for this colour type and bit depth - if false then the - * transform should have no effect on the image so there's not a lot of - * point running it. - */ - int (*add)(struct image_transform *this, - PNG_CONST struct image_transform **that, png_byte colour_type, - png_byte bit_depth); -} image_transform; - -typedef struct transform_display -{ - standard_display this; - - /* Parameters */ - png_modifier* pm; - PNG_CONST image_transform* transform_list; - - /* Local variables */ - png_byte output_colour_type; - png_byte output_bit_depth; - png_byte unpacked; - - /* Modifications (not necessarily used.) */ - gama_modification gama_mod; - chrm_modification chrm_mod; - srgb_modification srgb_mod; -} transform_display; - -/* Set sRGB, cHRM and gAMA transforms as required by the current encoding. */ -static void -transform_set_encoding(transform_display *this) -{ - /* Set up the png_modifier '_current' fields then use these to determine how - * to add appropriate chunks. - */ - png_modifier *pm = this->pm; - - modifier_set_encoding(pm); - - if (modifier_color_encoding_is_set(pm)) - { - if (modifier_color_encoding_is_sRGB(pm)) - srgb_modification_init(&this->srgb_mod, pm, PNG_sRGB_INTENT_ABSOLUTE); - - else - { - /* Set gAMA and cHRM separately. */ - gama_modification_init(&this->gama_mod, pm, pm->current_gamma); - - if (pm->current_encoding != 0) - chrm_modification_init(&this->chrm_mod, pm, pm->current_encoding); - } - } -} - -/* Three functions to end the list: */ -static void -image_transform_ini_end(PNG_CONST image_transform *this, - transform_display *that) -{ - UNUSED(this) - UNUSED(that) -} - -static void -image_transform_set_end(PNG_CONST image_transform *this, - transform_display *that, png_structp pp, png_infop pi) -{ - UNUSED(this) - UNUSED(that) - UNUSED(pp) - UNUSED(pi) -} - -/* At the end of the list recalculate the output image pixel value from the - * double precision values set up by the preceding 'mod' calls: - */ -static unsigned int -sample_scale(double sample_value, unsigned int scale) -{ - sample_value = floor(sample_value * scale + .5); - - /* Return NaN as 0: */ - if (!(sample_value > 0)) - sample_value = 0; - else if (sample_value > scale) - sample_value = scale; - - return (unsigned int)sample_value; -} - -static void -image_transform_mod_end(PNG_CONST image_transform *this, image_pixel *that, - png_const_structp pp, PNG_CONST transform_display *display) -{ - PNG_CONST unsigned int scale = (1U<<that->sample_depth)-1; - PNG_CONST int sig_bits = that->sig_bits; - - UNUSED(this) - UNUSED(pp) - UNUSED(display) - - /* At the end recalculate the digitized red green and blue values according - * to the current sample_depth of the pixel. - * - * The sample value is simply scaled to the maximum, checking for over - * and underflow (which can both happen for some image transforms, - * including simple size scaling, though libpng doesn't do that at present. - */ - that->red = sample_scale(that->redf, scale); - - /* This is a bit bogus; really the above calculation should use the red_sBIT - * value, not sample_depth, but because libpng does png_set_shift by just - * shifting the bits we get errors if we don't do it the same way. - */ - if (sig_bits && that->red_sBIT < that->sample_depth) - that->red >>= that->sample_depth - that->red_sBIT; - - /* The error value is increased, at the end, according to the lowest sBIT - * value seen. Common sense tells us that the intermediate integer - * representations are no more accurate than +/- 0.5 in the integral values, - * the sBIT allows the implementation to be worse than this. In addition the - * PNG specification actually permits any error within the range (-1..+1), - * but that is ignored here. Instead the final digitized value is compared, - * below to the digitized value of the error limits - this has the net effect - * of allowing (almost) +/-1 in the output value. It's difficult to see how - * any algorithm that digitizes intermediate results can be more accurate. - */ - that->rede += 1./(2*((1U<<that->red_sBIT)-1)); - - if (that->colour_type & PNG_COLOR_MASK_COLOR) - { - that->green = sample_scale(that->greenf, scale); - if (sig_bits && that->green_sBIT < that->sample_depth) - that->green >>= that->sample_depth - that->green_sBIT; - - that->blue = sample_scale(that->bluef, scale); - if (sig_bits && that->blue_sBIT < that->sample_depth) - that->blue >>= that->sample_depth - that->blue_sBIT; - - that->greene += 1./(2*((1U<<that->green_sBIT)-1)); - that->bluee += 1./(2*((1U<<that->blue_sBIT)-1)); - } - else - { - that->blue = that->green = that->red; - that->bluef = that->greenf = that->redf; - that->bluee = that->greene = that->rede; - } - - if ((that->colour_type & PNG_COLOR_MASK_ALPHA) || - that->colour_type == PNG_COLOR_TYPE_PALETTE) - { - that->alpha = sample_scale(that->alphaf, scale); - that->alphae += 1./(2*((1U<<that->alpha_sBIT)-1)); - } - else - { - that->alpha = scale; /* opaque */ - that->alphaf = 1; /* Override this. */ - that->alphae = 0; /* It's exact ;-) */ - } - - if (sig_bits && that->alpha_sBIT < that->sample_depth) - that->alpha >>= that->sample_depth - that->alpha_sBIT; -} - -/* Static 'end' structure: */ -static image_transform image_transform_end = -{ - "(end)", /* name */ - 1, /* enable */ - 0, /* list */ - 0, /* global_use */ - 0, /* local_use */ - 0, /* next */ - image_transform_ini_end, - image_transform_set_end, - image_transform_mod_end, - 0 /* never called, I want it to crash if it is! */ -}; - -/* Reader callbacks and implementations, where they differ from the standard - * ones. - */ -static void -transform_display_init(transform_display *dp, png_modifier *pm, png_uint_32 id, - PNG_CONST image_transform *transform_list) -{ - memset(dp, 0, sizeof *dp); - - /* Standard fields */ - standard_display_init(&dp->this, &pm->this, id, 0/*do_interlace*/, - pm->use_update_info); - - /* Parameter fields */ - dp->pm = pm; - dp->transform_list = transform_list; - - /* Local variable fields */ - dp->output_colour_type = 255; /* invalid */ - dp->output_bit_depth = 255; /* invalid */ - dp->unpacked = 0; /* not unpacked */ -} - -static void -transform_info_imp(transform_display *dp, png_structp pp, png_infop pi) -{ - /* Reuse the standard stuff as appropriate. */ - standard_info_part1(&dp->this, pp, pi); - - /* Now set the list of transforms. */ - dp->transform_list->set(dp->transform_list, dp, pp, pi); - - /* Update the info structure for these transforms: */ - { - int i = dp->this.use_update_info; - /* Always do one call, even if use_update_info is 0. */ - do - png_read_update_info(pp, pi); - while (--i > 0); - } - - /* And get the output information into the standard_display */ - standard_info_part2(&dp->this, pp, pi, 1/*images*/); - - /* Plus the extra stuff we need for the transform tests: */ - dp->output_colour_type = png_get_color_type(pp, pi); - dp->output_bit_depth = png_get_bit_depth(pp, pi); - - /* If png_set_filler is in action then fake the output color type to include - * an alpha channel where appropriate. - */ - if (dp->output_bit_depth >= 8 && (dp->output_colour_type == PNG_COLOR_TYPE_RGB || - dp->output_colour_type == PNG_COLOR_TYPE_GRAY) && dp->this.filler) - dp->output_colour_type |= 4; - - /* Validate the combination of colour type and bit depth that we are getting - * out of libpng; the semantics of something not in the PNG spec are, at - * best, unclear. - */ - switch (dp->output_colour_type) - { - case PNG_COLOR_TYPE_PALETTE: - if (dp->output_bit_depth > 8) goto error; - /*FALL THROUGH*/ - case PNG_COLOR_TYPE_GRAY: - if (dp->output_bit_depth == 1 || dp->output_bit_depth == 2 || - dp->output_bit_depth == 4) - break; - /*FALL THROUGH*/ - default: - if (dp->output_bit_depth == 8 || dp->output_bit_depth == 16) - break; - /*FALL THROUGH*/ - error: - { - char message[128]; - size_t pos; - - pos = safecat(message, sizeof message, 0, - "invalid final bit depth: colour type("); - pos = safecatn(message, sizeof message, pos, dp->output_colour_type); - pos = safecat(message, sizeof message, pos, ") with bit depth: "); - pos = safecatn(message, sizeof message, pos, dp->output_bit_depth); - - png_error(pp, message); - } - } - - /* Use a test pixel to check that the output agrees with what we expect - - * this avoids running the whole test if the output is unexpected. This also - * checks for internal errors. - */ - { - image_pixel test_pixel; - - memset(&test_pixel, 0, sizeof test_pixel); - test_pixel.colour_type = dp->this.colour_type; /* input */ - test_pixel.bit_depth = dp->this.bit_depth; - if (test_pixel.colour_type == PNG_COLOR_TYPE_PALETTE) - test_pixel.sample_depth = 8; - else - test_pixel.sample_depth = test_pixel.bit_depth; - /* Don't need sBIT here, but it must be set to non-zero to avoid - * arithmetic overflows. - */ - test_pixel.have_tRNS = dp->this.is_transparent != 0; - test_pixel.red_sBIT = test_pixel.green_sBIT = test_pixel.blue_sBIT = - test_pixel.alpha_sBIT = test_pixel.sample_depth; - - dp->transform_list->mod(dp->transform_list, &test_pixel, pp, dp); - - if (test_pixel.colour_type != dp->output_colour_type) - { - char message[128]; - size_t pos = safecat(message, sizeof message, 0, "colour type "); - - pos = safecatn(message, sizeof message, pos, dp->output_colour_type); - pos = safecat(message, sizeof message, pos, " expected "); - pos = safecatn(message, sizeof message, pos, test_pixel.colour_type); - - png_error(pp, message); - } - - if (test_pixel.bit_depth != dp->output_bit_depth) - { - char message[128]; - size_t pos = safecat(message, sizeof message, 0, "bit depth "); - - pos = safecatn(message, sizeof message, pos, dp->output_bit_depth); - pos = safecat(message, sizeof message, pos, " expected "); - pos = safecatn(message, sizeof message, pos, test_pixel.bit_depth); - - png_error(pp, message); - } - - /* If both bit depth and colour type are correct check the sample depth. - */ - if (test_pixel.colour_type == PNG_COLOR_TYPE_PALETTE && - test_pixel.sample_depth != 8) /* oops - internal error! */ - png_error(pp, "pngvalid: internal: palette sample depth not 8"); - else if (dp->unpacked && test_pixel.bit_depth != 8) - png_error(pp, "pngvalid: internal: bad unpacked pixel depth"); - else if (!dp->unpacked && test_pixel.colour_type != PNG_COLOR_TYPE_PALETTE - && test_pixel.bit_depth != test_pixel.sample_depth) - { - char message[128]; - size_t pos = safecat(message, sizeof message, 0, - "internal: sample depth "); - - /* Because unless something has set 'unpacked' or the image is palette - * mapped we expect the transform to keep sample depth and bit depth - * the same. - */ - pos = safecatn(message, sizeof message, pos, test_pixel.sample_depth); - pos = safecat(message, sizeof message, pos, " expected "); - pos = safecatn(message, sizeof message, pos, test_pixel.bit_depth); - - png_error(pp, message); - } - else if (test_pixel.bit_depth != dp->output_bit_depth) - { - /* This could be a libpng error too; libpng has not produced what we - * expect for the output bit depth. - */ - char message[128]; - size_t pos = safecat(message, sizeof message, 0, - "internal: bit depth "); - - pos = safecatn(message, sizeof message, pos, dp->output_bit_depth); - pos = safecat(message, sizeof message, pos, " expected "); - pos = safecatn(message, sizeof message, pos, test_pixel.bit_depth); - - png_error(pp, message); - } - } -} - -static void PNGCBAPI -transform_info(png_structp pp, png_infop pi) -{ - transform_info_imp(voidcast(transform_display*, png_get_progressive_ptr(pp)), - pp, pi); -} - -static void -transform_range_check(png_const_structp pp, unsigned int r, unsigned int g, - unsigned int b, unsigned int a, unsigned int in_digitized, double in, - unsigned int out, png_byte sample_depth, double err, double limit, - PNG_CONST char *name, double digitization_error) -{ - /* Compare the scaled, digitzed, values of our local calculation (in+-err) - * with the digitized values libpng produced; 'sample_depth' is the actual - * digitization depth of the libpng output colors (the bit depth except for - * palette images where it is always 8.) The check on 'err' is to detect - * internal errors in pngvalid itself. - */ - unsigned int max = (1U<<sample_depth)-1; - double in_min = ceil((in-err)*max - digitization_error); - double in_max = floor((in+err)*max + digitization_error); - if (err > limit || !(out >= in_min && out <= in_max)) - { - char message[256]; - size_t pos; - - pos = safecat(message, sizeof message, 0, name); - pos = safecat(message, sizeof message, pos, " output value error: rgba("); - pos = safecatn(message, sizeof message, pos, r); - pos = safecat(message, sizeof message, pos, ","); - pos = safecatn(message, sizeof message, pos, g); - pos = safecat(message, sizeof message, pos, ","); - pos = safecatn(message, sizeof message, pos, b); - pos = safecat(message, sizeof message, pos, ","); - pos = safecatn(message, sizeof message, pos, a); - pos = safecat(message, sizeof message, pos, "): "); - pos = safecatn(message, sizeof message, pos, out); - pos = safecat(message, sizeof message, pos, " expected: "); - pos = safecatn(message, sizeof message, pos, in_digitized); - pos = safecat(message, sizeof message, pos, " ("); - pos = safecatd(message, sizeof message, pos, (in-err)*max, 3); - pos = safecat(message, sizeof message, pos, ".."); - pos = safecatd(message, sizeof message, pos, (in+err)*max, 3); - pos = safecat(message, sizeof message, pos, ")"); - - png_error(pp, message); - } -} - -static void -transform_image_validate(transform_display *dp, png_const_structp pp, - png_infop pi) -{ - /* Constants for the loop below: */ - PNG_CONST png_store* PNG_CONST ps = dp->this.ps; - PNG_CONST png_byte in_ct = dp->this.colour_type; - PNG_CONST png_byte in_bd = dp->this.bit_depth; - PNG_CONST png_uint_32 w = dp->this.w; - PNG_CONST png_uint_32 h = dp->this.h; - PNG_CONST png_byte out_ct = dp->output_colour_type; - PNG_CONST png_byte out_bd = dp->output_bit_depth; - PNG_CONST png_byte sample_depth = (png_byte)(out_ct == - PNG_COLOR_TYPE_PALETTE ? 8 : out_bd); - PNG_CONST png_byte red_sBIT = dp->this.red_sBIT; - PNG_CONST png_byte green_sBIT = dp->this.green_sBIT; - PNG_CONST png_byte blue_sBIT = dp->this.blue_sBIT; - PNG_CONST png_byte alpha_sBIT = dp->this.alpha_sBIT; - PNG_CONST int have_tRNS = dp->this.is_transparent; - double digitization_error; - - store_palette out_palette; - png_uint_32 y; - - UNUSED(pi) - - /* Check for row overwrite errors */ - store_image_check(dp->this.ps, pp, 0); - - /* Read the palette corresponding to the output if the output colour type - * indicates a palette, othewise set out_palette to garbage. - */ - if (out_ct == PNG_COLOR_TYPE_PALETTE) - { - /* Validate that the palette count itself has not changed - this is not - * expected. - */ - int npalette = (-1); - - (void)read_palette(out_palette, &npalette, pp, pi); - if (npalette != dp->this.npalette) - png_error(pp, "unexpected change in palette size"); - - digitization_error = .5; - } - else - { - png_byte in_sample_depth; - - memset(out_palette, 0x5e, sizeof out_palette); - - /* use-input-precision means assume that if the input has 8 bit (or less) - * samples and the output has 16 bit samples the calculations will be done - * with 8 bit precision, not 16. - */ - if (in_ct == PNG_COLOR_TYPE_PALETTE || in_bd < 16) - in_sample_depth = 8; - else - in_sample_depth = in_bd; - - if (sample_depth != 16 || in_sample_depth > 8 || - !dp->pm->calculations_use_input_precision) - digitization_error = .5; - - /* Else calculations are at 8 bit precision, and the output actually - * consists of scaled 8-bit values, so scale .5 in 8 bits to the 16 bits: - */ - else - digitization_error = .5 * 257; - } - - for (y=0; y<h; ++y) - { - png_const_bytep PNG_CONST pRow = store_image_row(ps, pp, 0, y); - png_uint_32 x; - - /* The original, standard, row pre-transforms. */ - png_byte std[STANDARD_ROWMAX]; - - transform_row(pp, std, in_ct, in_bd, y); - - /* Go through each original pixel transforming it and comparing with what - * libpng did to the same pixel. - */ - for (x=0; x<w; ++x) - { - image_pixel in_pixel, out_pixel; - unsigned int r, g, b, a; - - /* Find out what we think the pixel should be: */ - image_pixel_init(&in_pixel, std, in_ct, in_bd, x, dp->this.palette, - NULL); - - in_pixel.red_sBIT = red_sBIT; - in_pixel.green_sBIT = green_sBIT; - in_pixel.blue_sBIT = blue_sBIT; - in_pixel.alpha_sBIT = alpha_sBIT; - in_pixel.have_tRNS = have_tRNS != 0; - - /* For error detection, below. */ - r = in_pixel.red; - g = in_pixel.green; - b = in_pixel.blue; - a = in_pixel.alpha; - - /* This applies the transforms to the input date, including output - * format operations which must be used when reading the output - * pixel that libpng produces. - */ - dp->transform_list->mod(dp->transform_list, &in_pixel, pp, dp); - - /* Read the output pixel and compare it to what we got, we don't - * use the error field here, so no need to update sBIT. in_pixel - * says whether we expect libpng to change the output format. - */ - image_pixel_init(&out_pixel, pRow, out_ct, out_bd, x, out_palette, - &in_pixel); - - /* We don't expect changes to the index here even if the bit depth is - * changed. - */ - if (in_ct == PNG_COLOR_TYPE_PALETTE && - out_ct == PNG_COLOR_TYPE_PALETTE) - { - if (in_pixel.palette_index != out_pixel.palette_index) - png_error(pp, "unexpected transformed palette index"); - } - - /* Check the colours for palette images too - in fact the palette could - * be separately verified itself in most cases. - */ - if (in_pixel.red != out_pixel.red) - transform_range_check(pp, r, g, b, a, in_pixel.red, in_pixel.redf, - out_pixel.red, sample_depth, in_pixel.rede, - dp->pm->limit + 1./(2*((1U<<in_pixel.red_sBIT)-1)), "red/gray", - digitization_error); - - if ((out_ct & PNG_COLOR_MASK_COLOR) != 0 && - in_pixel.green != out_pixel.green) - transform_range_check(pp, r, g, b, a, in_pixel.green, - in_pixel.greenf, out_pixel.green, sample_depth, in_pixel.greene, - dp->pm->limit + 1./(2*((1U<<in_pixel.green_sBIT)-1)), "green", - digitization_error); - - if ((out_ct & PNG_COLOR_MASK_COLOR) != 0 && - in_pixel.blue != out_pixel.blue) - transform_range_check(pp, r, g, b, a, in_pixel.blue, in_pixel.bluef, - out_pixel.blue, sample_depth, in_pixel.bluee, - dp->pm->limit + 1./(2*((1U<<in_pixel.blue_sBIT)-1)), "blue", - digitization_error); - - if ((out_ct & PNG_COLOR_MASK_ALPHA) != 0 && - in_pixel.alpha != out_pixel.alpha) - transform_range_check(pp, r, g, b, a, in_pixel.alpha, - in_pixel.alphaf, out_pixel.alpha, sample_depth, in_pixel.alphae, - dp->pm->limit + 1./(2*((1U<<in_pixel.alpha_sBIT)-1)), "alpha", - digitization_error); - } /* pixel (x) loop */ - } /* row (y) loop */ - - /* Record that something was actually checked to avoid a false positive. */ - dp->this.ps->validated = 1; -} - -static void PNGCBAPI -transform_end(png_structp ppIn, png_infop pi) -{ - png_const_structp pp = ppIn; - transform_display *dp = voidcast(transform_display*, - png_get_progressive_ptr(pp)); - - if (!dp->this.speed) - transform_image_validate(dp, pp, pi); - else - dp->this.ps->validated = 1; -} - -/* A single test run. */ -static void -transform_test(png_modifier *pmIn, PNG_CONST png_uint_32 idIn, - PNG_CONST image_transform* transform_listIn, PNG_CONST char * volatile name) -{ - transform_display d; - context(&pmIn->this, fault); - - transform_display_init(&d, pmIn, idIn, transform_listIn); - - Try - { - size_t pos = 0; - png_structp pp; - png_infop pi; - char full_name[256]; - - /* Make sure the encoding fields are correct and enter the required - * modifications. - */ - transform_set_encoding(&d); - - /* Add any modifications required by the transform list. */ - d.transform_list->ini(d.transform_list, &d); - - /* Add the color space information, if any, to the name. */ - pos = safecat(full_name, sizeof full_name, pos, name); - pos = safecat_current_encoding(full_name, sizeof full_name, pos, d.pm); - - /* Get a png_struct for reading the image. */ - pp = set_modifier_for_read(d.pm, &pi, d.this.id, full_name); - standard_palette_init(&d.this); - -# if 0 - /* Logging (debugging only) */ - { - char buffer[256]; - - (void)store_message(&d.pm->this, pp, buffer, sizeof buffer, 0, - "running test"); - - fprintf(stderr, "%s\n", buffer); - } -# endif - - /* Introduce the correct read function. */ - if (d.pm->this.progressive) - { - /* Share the row function with the standard implementation. */ - png_set_progressive_read_fn(pp, &d, transform_info, progressive_row, - transform_end); - - /* Now feed data into the reader until we reach the end: */ - modifier_progressive_read(d.pm, pp, pi); - } - else - { - /* modifier_read expects a png_modifier* */ - png_set_read_fn(pp, d.pm, modifier_read); - - /* Check the header values: */ - png_read_info(pp, pi); - - /* Process the 'info' requirements. Only one image is generated */ - transform_info_imp(&d, pp, pi); - - sequential_row(&d.this, pp, pi, -1, 0); - - if (!d.this.speed) - transform_image_validate(&d, pp, pi); - else - d.this.ps->validated = 1; - } - - modifier_reset(d.pm); - } - - Catch(fault) - { - modifier_reset(voidcast(png_modifier*,(void*)fault)); - } -} - -/* The transforms: */ -#define ITSTRUCT(name) image_transform_##name -#define ITDATA(name) image_transform_data_##name -#define image_transform_ini image_transform_default_ini -#define IT(name)\ -static image_transform ITSTRUCT(name) =\ -{\ - #name,\ - 1, /*enable*/\ - &PT, /*list*/\ - 0, /*global_use*/\ - 0, /*local_use*/\ - 0, /*next*/\ - image_transform_ini,\ - image_transform_png_set_##name##_set,\ - image_transform_png_set_##name##_mod,\ - image_transform_png_set_##name##_add\ -} -#define PT ITSTRUCT(end) /* stores the previous transform */ - -/* To save code: */ -static void -image_transform_default_ini(PNG_CONST image_transform *this, - transform_display *that) -{ - this->next->ini(this->next, that); -} - -#ifdef PNG_READ_BACKGROUND_SUPPORTED -static int -image_transform_default_add(image_transform *this, - PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth) -{ - UNUSED(colour_type) - UNUSED(bit_depth) - - this->next = *that; - *that = this; - - return 1; -} -#endif - -#ifdef PNG_READ_EXPAND_SUPPORTED -/* png_set_palette_to_rgb */ -static void -image_transform_png_set_palette_to_rgb_set(PNG_CONST image_transform *this, - transform_display *that, png_structp pp, png_infop pi) -{ - png_set_palette_to_rgb(pp); - this->next->set(this->next, that, pp, pi); -} - -static void -image_transform_png_set_palette_to_rgb_mod(PNG_CONST image_transform *this, - image_pixel *that, png_const_structp pp, - PNG_CONST transform_display *display) -{ - if (that->colour_type == PNG_COLOR_TYPE_PALETTE) - image_pixel_convert_PLTE(that); - - this->next->mod(this->next, that, pp, display); -} - -static int -image_transform_png_set_palette_to_rgb_add(image_transform *this, - PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth) -{ - UNUSED(bit_depth) - - this->next = *that; - *that = this; - - return colour_type == PNG_COLOR_TYPE_PALETTE; -} - -IT(palette_to_rgb); -#undef PT -#define PT ITSTRUCT(palette_to_rgb) -#endif /* PNG_READ_EXPAND_SUPPORTED */ - -#ifdef PNG_READ_EXPAND_SUPPORTED -/* png_set_tRNS_to_alpha */ -static void -image_transform_png_set_tRNS_to_alpha_set(PNG_CONST image_transform *this, - transform_display *that, png_structp pp, png_infop pi) -{ - png_set_tRNS_to_alpha(pp); - this->next->set(this->next, that, pp, pi); -} - -static void -image_transform_png_set_tRNS_to_alpha_mod(PNG_CONST image_transform *this, - image_pixel *that, png_const_structp pp, - PNG_CONST transform_display *display) -{ - /* LIBPNG BUG: this always forces palette images to RGB. */ - if (that->colour_type == PNG_COLOR_TYPE_PALETTE) - image_pixel_convert_PLTE(that); - - /* This effectively does an 'expand' only if there is some transparency to - * convert to an alpha channel. - */ - if (that->have_tRNS) - image_pixel_add_alpha(that, &display->this); - - /* LIBPNG BUG: otherwise libpng still expands to 8 bits! */ - else - { - if (that->bit_depth < 8) - that->bit_depth =8; - if (that->sample_depth < 8) - that->sample_depth = 8; - } - - this->next->mod(this->next, that, pp, display); -} - -static int -image_transform_png_set_tRNS_to_alpha_add(image_transform *this, - PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth) -{ - UNUSED(bit_depth) - - this->next = *that; - *that = this; - - /* We don't know yet whether there will be a tRNS chunk, but we know that - * this transformation should do nothing if there already is an alpha - * channel. - */ - return (colour_type & PNG_COLOR_MASK_ALPHA) == 0; -} - -IT(tRNS_to_alpha); -#undef PT -#define PT ITSTRUCT(tRNS_to_alpha) -#endif /* PNG_READ_EXPAND_SUPPORTED */ - -#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED -/* png_set_gray_to_rgb */ -static void -image_transform_png_set_gray_to_rgb_set(PNG_CONST image_transform *this, - transform_display *that, png_structp pp, png_infop pi) -{ - png_set_gray_to_rgb(pp); - this->next->set(this->next, that, pp, pi); -} - -static void -image_transform_png_set_gray_to_rgb_mod(PNG_CONST image_transform *this, - image_pixel *that, png_const_structp pp, - PNG_CONST transform_display *display) -{ - /* NOTE: we can actually pend the tRNS processing at this point because we - * can correctly recognize the original pixel value even though we have - * mapped the one gray channel to the three RGB ones, but in fact libpng - * doesn't do this, so we don't either. - */ - if ((that->colour_type & PNG_COLOR_MASK_COLOR) == 0 && that->have_tRNS) - image_pixel_add_alpha(that, &display->this); - - /* Simply expand the bit depth and alter the colour type as required. */ - if (that->colour_type == PNG_COLOR_TYPE_GRAY) - { - /* RGB images have a bit depth at least equal to '8' */ - if (that->bit_depth < 8) - that->sample_depth = that->bit_depth = 8; - - /* And just changing the colour type works here because the green and blue - * channels are being maintained in lock-step with the red/gray: - */ - that->colour_type = PNG_COLOR_TYPE_RGB; - } - - else if (that->colour_type == PNG_COLOR_TYPE_GRAY_ALPHA) - that->colour_type = PNG_COLOR_TYPE_RGB_ALPHA; - - this->next->mod(this->next, that, pp, display); -} - -static int -image_transform_png_set_gray_to_rgb_add(image_transform *this, - PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth) -{ - UNUSED(bit_depth) - - this->next = *that; - *that = this; - - return (colour_type & PNG_COLOR_MASK_COLOR) == 0; -} - -IT(gray_to_rgb); -#undef PT -#define PT ITSTRUCT(gray_to_rgb) -#endif /* PNG_READ_GRAY_TO_RGB_SUPPORTED */ - -#ifdef PNG_READ_EXPAND_SUPPORTED -/* png_set_expand */ -static void -image_transform_png_set_expand_set(PNG_CONST image_transform *this, - transform_display *that, png_structp pp, png_infop pi) -{ - png_set_expand(pp); - this->next->set(this->next, that, pp, pi); -} - -static void -image_transform_png_set_expand_mod(PNG_CONST image_transform *this, - image_pixel *that, png_const_structp pp, - PNG_CONST transform_display *display) -{ - /* The general expand case depends on what the colour type is: */ - if (that->colour_type == PNG_COLOR_TYPE_PALETTE) - image_pixel_convert_PLTE(that); - else if (that->bit_depth < 8) /* grayscale */ - that->sample_depth = that->bit_depth = 8; - - if (that->have_tRNS) - image_pixel_add_alpha(that, &display->this); - - this->next->mod(this->next, that, pp, display); -} - -static int -image_transform_png_set_expand_add(image_transform *this, - PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth) -{ - UNUSED(bit_depth) - - this->next = *that; - *that = this; - - /* 'expand' should do nothing for RGBA or GA input - no tRNS and the bit - * depth is at least 8 already. - */ - return (colour_type & PNG_COLOR_MASK_ALPHA) == 0; -} - -IT(expand); -#undef PT -#define PT ITSTRUCT(expand) -#endif /* PNG_READ_EXPAND_SUPPORTED */ - -#ifdef PNG_READ_EXPAND_SUPPORTED -/* png_set_expand_gray_1_2_4_to_8 - * LIBPNG BUG: this just does an 'expand' - */ -static void -image_transform_png_set_expand_gray_1_2_4_to_8_set( - PNG_CONST image_transform *this, transform_display *that, png_structp pp, - png_infop pi) -{ - png_set_expand_gray_1_2_4_to_8(pp); - this->next->set(this->next, that, pp, pi); -} - -static void -image_transform_png_set_expand_gray_1_2_4_to_8_mod( - PNG_CONST image_transform *this, image_pixel *that, png_const_structp pp, - PNG_CONST transform_display *display) -{ - image_transform_png_set_expand_mod(this, that, pp, display); -} - -static int -image_transform_png_set_expand_gray_1_2_4_to_8_add(image_transform *this, - PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth) -{ - return image_transform_png_set_expand_add(this, that, colour_type, - bit_depth); -} - -IT(expand_gray_1_2_4_to_8); -#undef PT -#define PT ITSTRUCT(expand_gray_1_2_4_to_8) -#endif /* PNG_READ_EXPAND_SUPPORTED */ - -#ifdef PNG_READ_EXPAND_16_SUPPORTED -/* png_set_expand_16 */ -static void -image_transform_png_set_expand_16_set(PNG_CONST image_transform *this, - transform_display *that, png_structp pp, png_infop pi) -{ - png_set_expand_16(pp); - this->next->set(this->next, that, pp, pi); -} - -static void -image_transform_png_set_expand_16_mod(PNG_CONST image_transform *this, - image_pixel *that, png_const_structp pp, - PNG_CONST transform_display *display) -{ - /* Expect expand_16 to expand everything to 16 bits as a result of also - * causing 'expand' to happen. - */ - if (that->colour_type == PNG_COLOR_TYPE_PALETTE) - image_pixel_convert_PLTE(that); - - if (that->have_tRNS) - image_pixel_add_alpha(that, &display->this); - - if (that->bit_depth < 16) - that->sample_depth = that->bit_depth = 16; - - this->next->mod(this->next, that, pp, display); -} - -static int -image_transform_png_set_expand_16_add(image_transform *this, - PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth) -{ - UNUSED(colour_type) - - this->next = *that; - *that = this; - - /* expand_16 does something unless the bit depth is already 16. */ - return bit_depth < 16; -} - -IT(expand_16); -#undef PT -#define PT ITSTRUCT(expand_16) -#endif /* PNG_READ_EXPAND_16_SUPPORTED */ - -#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED /* API added in 1.5.4 */ -/* png_set_scale_16 */ -static void -image_transform_png_set_scale_16_set(PNG_CONST image_transform *this, - transform_display *that, png_structp pp, png_infop pi) -{ - png_set_scale_16(pp); - this->next->set(this->next, that, pp, pi); -} - -static void -image_transform_png_set_scale_16_mod(PNG_CONST image_transform *this, - image_pixel *that, png_const_structp pp, - PNG_CONST transform_display *display) -{ - if (that->bit_depth == 16) - { - that->sample_depth = that->bit_depth = 8; - if (that->red_sBIT > 8) that->red_sBIT = 8; - if (that->green_sBIT > 8) that->green_sBIT = 8; - if (that->blue_sBIT > 8) that->blue_sBIT = 8; - if (that->alpha_sBIT > 8) that->alpha_sBIT = 8; - } - - this->next->mod(this->next, that, pp, display); -} - -static int -image_transform_png_set_scale_16_add(image_transform *this, - PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth) -{ - UNUSED(colour_type) - - this->next = *that; - *that = this; - - return bit_depth > 8; -} - -IT(scale_16); -#undef PT -#define PT ITSTRUCT(scale_16) -#endif /* PNG_READ_SCALE_16_TO_8_SUPPORTED (1.5.4 on) */ - -#ifdef PNG_READ_16_TO_8_SUPPORTED /* the default before 1.5.4 */ -/* png_set_strip_16 */ -static void -image_transform_png_set_strip_16_set(PNG_CONST image_transform *this, - transform_display *that, png_structp pp, png_infop pi) -{ - png_set_strip_16(pp); - this->next->set(this->next, that, pp, pi); -} - -static void -image_transform_png_set_strip_16_mod(PNG_CONST image_transform *this, - image_pixel *that, png_const_structp pp, - PNG_CONST transform_display *display) -{ - if (that->bit_depth == 16) - { - that->sample_depth = that->bit_depth = 8; - if (that->red_sBIT > 8) that->red_sBIT = 8; - if (that->green_sBIT > 8) that->green_sBIT = 8; - if (that->blue_sBIT > 8) that->blue_sBIT = 8; - if (that->alpha_sBIT > 8) that->alpha_sBIT = 8; - - /* Prior to 1.5.4 png_set_strip_16 would use an 'accurate' method if this - * configuration option is set. From 1.5.4 the flag is never set and the - * 'scale' API (above) must be used. - */ -# ifdef PNG_READ_ACCURATE_SCALE_SUPPORTED -# if PNG_LIBPNG_VER >= 10504 -# error PNG_READ_ACCURATE_SCALE should not be set -# endif - - /* The strip 16 algorithm drops the low 8 bits rather than calculating - * 1/257, so we need to adjust the permitted errors appropriately: - * Notice that this is only relevant prior to the addition of the - * png_set_scale_16 API in 1.5.4 (but 1.5.4+ always defines the above!) - */ - { - PNG_CONST double d = (255-128.5)/65535; - that->rede += d; - that->greene += d; - that->bluee += d; - that->alphae += d; - } -# endif - } - - this->next->mod(this->next, that, pp, display); -} - -static int -image_transform_png_set_strip_16_add(image_transform *this, - PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth) -{ - UNUSED(colour_type) - - this->next = *that; - *that = this; - - return bit_depth > 8; -} - -IT(strip_16); -#undef PT -#define PT ITSTRUCT(strip_16) -#endif /* PNG_READ_16_TO_8_SUPPORTED */ - -#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED -/* png_set_strip_alpha */ -static void -image_transform_png_set_strip_alpha_set(PNG_CONST image_transform *this, - transform_display *that, png_structp pp, png_infop pi) -{ - png_set_strip_alpha(pp); - this->next->set(this->next, that, pp, pi); -} - -static void -image_transform_png_set_strip_alpha_mod(PNG_CONST image_transform *this, - image_pixel *that, png_const_structp pp, - PNG_CONST transform_display *display) -{ - if (that->colour_type == PNG_COLOR_TYPE_GRAY_ALPHA) - that->colour_type = PNG_COLOR_TYPE_GRAY; - else if (that->colour_type == PNG_COLOR_TYPE_RGB_ALPHA) - that->colour_type = PNG_COLOR_TYPE_RGB; - - that->have_tRNS = 0; - that->alphaf = 1; - - this->next->mod(this->next, that, pp, display); -} - -static int -image_transform_png_set_strip_alpha_add(image_transform *this, - PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth) -{ - UNUSED(bit_depth) - - this->next = *that; - *that = this; - - return (colour_type & PNG_COLOR_MASK_ALPHA) != 0; -} - -IT(strip_alpha); -#undef PT -#define PT ITSTRUCT(strip_alpha) -#endif /* PNG_READ_STRIP_ALPHA_SUPPORTED */ - -#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED -/* png_set_rgb_to_gray(png_structp, int err_action, double red, double green) - * png_set_rgb_to_gray_fixed(png_structp, int err_action, png_fixed_point red, - * png_fixed_point green) - * png_get_rgb_to_gray_status - * - * The 'default' test here uses values known to be used inside libpng: - * - * red: 6968 - * green: 23434 - * blue: 2366 - * - * These values are being retained for compatibility, along with the somewhat - * broken truncation calculation in the fast-and-inaccurate code path. Older - * versions of libpng will fail the accuracy tests below because they use the - * truncation algorithm everywhere. - */ -#define data ITDATA(rgb_to_gray) -static struct -{ - double gamma; /* File gamma to use in processing */ - - /* The following are the parameters for png_set_rgb_to_gray: */ -# ifdef PNG_FLOATING_POINT_SUPPORTED - double red_to_set; - double green_to_set; -# else - png_fixed_point red_to_set; - png_fixed_point green_to_set; -# endif - - /* The actual coefficients: */ - double red_coefficient; - double green_coefficient; - double blue_coefficient; - - /* Set if the coeefficients have been overridden. */ - int coefficients_overridden; -} data; - -#undef image_transform_ini -#define image_transform_ini image_transform_png_set_rgb_to_gray_ini -static void -image_transform_png_set_rgb_to_gray_ini(PNG_CONST image_transform *this, - transform_display *that) -{ - png_modifier *pm = that->pm; - PNG_CONST color_encoding *e = pm->current_encoding; - - UNUSED(this) - - /* Since we check the encoding this flag must be set: */ - pm->test_uses_encoding = 1; - - /* If 'e' is not NULL chromaticity information is present and either a cHRM - * or an sRGB chunk will be inserted. - */ - if (e != 0) - { - /* Coefficients come from the encoding, but may need to be normalized to a - * white point Y of 1.0 - */ - PNG_CONST double whiteY = e->red.Y + e->green.Y + e->blue.Y; - - data.red_coefficient = e->red.Y; - data.green_coefficient = e->green.Y; - data.blue_coefficient = e->blue.Y; - - if (whiteY != 1) - { - data.red_coefficient /= whiteY; - data.green_coefficient /= whiteY; - data.blue_coefficient /= whiteY; - } - } - - else - { - /* The default (built in) coeffcients, as above: */ - data.red_coefficient = 6968 / 32768.; - data.green_coefficient = 23434 / 32768.; - data.blue_coefficient = 2366 / 32768.; - } - - data.gamma = pm->current_gamma; - - /* If not set then the calculations assume linear encoding (implicitly): */ - if (data.gamma == 0) - data.gamma = 1; - - /* The arguments to png_set_rgb_to_gray can override the coefficients implied - * by the color space encoding. If doing exhaustive checks do the override - * in each case, otherwise do it randomly. - */ - if (pm->test_exhaustive) - { - /* First time in coefficients_overridden is 0, the following sets it to 1, - * so repeat if it is set. If a test fails this may mean we subsequently - * skip a non-override test, ignore that. - */ - data.coefficients_overridden = !data.coefficients_overridden; - pm->repeat = data.coefficients_overridden != 0; - } - - else - data.coefficients_overridden = random_choice(); - - if (data.coefficients_overridden) - { - /* These values override the color encoding defaults, simply use random - * numbers. - */ - png_uint_32 ru; - double total; - - RANDOMIZE(ru); - data.green_coefficient = total = (ru & 0xffff) / 65535.; - ru >>= 16; - data.red_coefficient = (1 - total) * (ru & 0xffff) / 65535.; - total += data.red_coefficient; - data.blue_coefficient = 1 - total; - -# ifdef PNG_FLOATING_POINT_SUPPORTED - data.red_to_set = data.red_coefficient; - data.green_to_set = data.green_coefficient; -# else - data.red_to_set = fix(data.red_coefficient); - data.green_to_set = fix(data.green_coefficient); -# endif - - /* The following just changes the error messages: */ - pm->encoding_ignored = 1; - } - - else - { - data.red_to_set = -1; - data.green_to_set = -1; - } - - /* Adjust the error limit in the png_modifier because of the larger errors - * produced in the digitization during the gamma handling. - */ - if (data.gamma != 1) /* Use gamma tables */ - { - if (that->this.bit_depth == 16 || pm->assume_16_bit_calculations) - { - /* The computations have the form: - * - * r * rc + g * gc + b * bc - * - * Each component of which is +/-1/65535 from the gamma_to_1 table - * lookup, resulting in a base error of +/-6. The gamma_from_1 - * conversion adds another +/-2 in the 16-bit case and - * +/-(1<<(15-PNG_MAX_GAMMA_8)) in the 8-bit case. - */ - that->pm->limit += pow( -# if PNG_MAX_GAMMA_8 < 14 - (that->this.bit_depth == 16 ? 8. : - 6. + (1<<(15-PNG_MAX_GAMMA_8))) -# else - 8. -# endif - /65535, data.gamma); - } - - else - { - /* Rounding to 8 bits in the linear space causes massive errors which - * will trigger the error check in transform_range_check. Fix that - * here by taking the gamma encoding into account. - * - * When DIGITIZE is set because a pre-1.7 version of libpng is being - * tested allow a bigger slack. - * - * NOTE: this magic number was determined by experiment to be 1.25. - * There's no great merit to the value below, however it only affects - * the limit used for checking for internal calculation errors, not - * the actual limit imposed by pngvalid on the output errors. - */ - that->pm->limit += pow( -# if DIGITIZE - 1.25 -# else - 1.0 -# endif - /255, data.gamma); - } - } - - else - { - /* With no gamma correction a large error comes from the truncation of the - * calculation in the 8 bit case, allow for that here. - */ - if (that->this.bit_depth != 16 && !pm->assume_16_bit_calculations) - that->pm->limit += 4E-3; - } -} - -static void -image_transform_png_set_rgb_to_gray_set(PNG_CONST image_transform *this, - transform_display *that, png_structp pp, png_infop pi) -{ - PNG_CONST int error_action = 1; /* no error, no defines in png.h */ - -# ifdef PNG_FLOATING_POINT_SUPPORTED - png_set_rgb_to_gray(pp, error_action, data.red_to_set, data.green_to_set); -# else - png_set_rgb_to_gray_fixed(pp, error_action, data.red_to_set, - data.green_to_set); -# endif - -# ifdef PNG_READ_cHRM_SUPPORTED - if (that->pm->current_encoding != 0) - { - /* We have an encoding so a cHRM chunk may have been set; if so then - * check that the libpng APIs give the correct (X,Y,Z) values within - * some margin of error for the round trip through the chromaticity - * form. - */ -# ifdef PNG_FLOATING_POINT_SUPPORTED -# define API_function png_get_cHRM_XYZ -# define API_form "FP" -# define API_type double -# define API_cvt(x) (x) -# else -# define API_function png_get_cHRM_XYZ_fixed -# define API_form "fixed" -# define API_type png_fixed_point -# define API_cvt(x) ((double)(x)/PNG_FP_1) -# endif - - API_type rX, gX, bX; - API_type rY, gY, bY; - API_type rZ, gZ, bZ; - - if ((API_function(pp, pi, &rX, &rY, &rZ, &gX, &gY, &gZ, &bX, &bY, &bZ) - & PNG_INFO_cHRM) != 0) - { - double maxe; - PNG_CONST char *el; - color_encoding e, o; - - /* Expect libpng to return a normalized result, but the original - * color space encoding may not be normalized. - */ - modifier_current_encoding(that->pm, &o); - normalize_color_encoding(&o); - - /* Sanity check the pngvalid code - the coefficients should match - * the normalized Y values of the encoding unless they were - * overridden. - */ - if (data.red_to_set == -1 && data.green_to_set == -1 && - (fabs(o.red.Y - data.red_coefficient) > DBL_EPSILON || - fabs(o.green.Y - data.green_coefficient) > DBL_EPSILON || - fabs(o.blue.Y - data.blue_coefficient) > DBL_EPSILON)) - png_error(pp, "internal pngvalid cHRM coefficient error"); - - /* Generate a colour space encoding. */ - e.gamma = o.gamma; /* not used */ - e.red.X = API_cvt(rX); - e.red.Y = API_cvt(rY); - e.red.Z = API_cvt(rZ); - e.green.X = API_cvt(gX); - e.green.Y = API_cvt(gY); - e.green.Z = API_cvt(gZ); - e.blue.X = API_cvt(bX); - e.blue.Y = API_cvt(bY); - e.blue.Z = API_cvt(bZ); - - /* This should match the original one from the png_modifier, within - * the range permitted by the libpng fixed point representation. - */ - maxe = 0; - el = "-"; /* Set to element name with error */ - -# define CHECK(col,x)\ - {\ - double err = fabs(o.col.x - e.col.x);\ - if (err > maxe)\ - {\ - maxe = err;\ - el = #col "(" #x ")";\ - }\ - } - - CHECK(red,X) - CHECK(red,Y) - CHECK(red,Z) - CHECK(green,X) - CHECK(green,Y) - CHECK(green,Z) - CHECK(blue,X) - CHECK(blue,Y) - CHECK(blue,Z) - - /* Here in both fixed and floating cases to check the values read - * from the cHRm chunk. PNG uses fixed point in the cHRM chunk, so - * we can't expect better than +/-.5E-5 on the result, allow 1E-5. - */ - if (maxe >= 1E-5) - { - size_t pos = 0; - char buffer[256]; - - pos = safecat(buffer, sizeof buffer, pos, API_form); - pos = safecat(buffer, sizeof buffer, pos, " cHRM "); - pos = safecat(buffer, sizeof buffer, pos, el); - pos = safecat(buffer, sizeof buffer, pos, " error: "); - pos = safecatd(buffer, sizeof buffer, pos, maxe, 7); - pos = safecat(buffer, sizeof buffer, pos, " "); - /* Print the color space without the gamma value: */ - pos = safecat_color_encoding(buffer, sizeof buffer, pos, &o, 0); - pos = safecat(buffer, sizeof buffer, pos, " -> "); - pos = safecat_color_encoding(buffer, sizeof buffer, pos, &e, 0); - - png_error(pp, buffer); - } - } - } -# endif /* READ_cHRM */ - - this->next->set(this->next, that, pp, pi); -} - -static void -image_transform_png_set_rgb_to_gray_mod(PNG_CONST image_transform *this, - image_pixel *that, png_const_structp pp, - PNG_CONST transform_display *display) -{ - if ((that->colour_type & PNG_COLOR_MASK_COLOR) != 0) - { - double gray, err; - - if (that->colour_type == PNG_COLOR_TYPE_PALETTE) - image_pixel_convert_PLTE(that); - - /* Image now has RGB channels... */ -# if DIGITIZE - { - PNG_CONST png_modifier *pm = display->pm; - const unsigned int sample_depth = that->sample_depth; - const unsigned int calc_depth = (pm->assume_16_bit_calculations ? 16 : - sample_depth); - const unsigned int gamma_depth = (sample_depth == 16 ? 16 : - (pm->assume_16_bit_calculations ? PNG_MAX_GAMMA_8 : sample_depth)); - int isgray; - double r, g, b; - double rlo, rhi, glo, ghi, blo, bhi, graylo, grayhi; - - /* Do this using interval arithmetic, otherwise it is too difficult to - * handle the errors correctly. - * - * To handle the gamma correction work out the upper and lower bounds - * of the digitized value. Assume rounding here - normally the values - * will be identical after this operation if there is only one - * transform, feel free to delete the png_error checks on this below in - * the future (this is just me trying to ensure it works!) - */ - r = rlo = rhi = that->redf; - rlo -= that->rede; - rlo = digitize(rlo, calc_depth, 1/*round*/); - rhi += that->rede; - rhi = digitize(rhi, calc_depth, 1/*round*/); - - g = glo = ghi = that->greenf; - glo -= that->greene; - glo = digitize(glo, calc_depth, 1/*round*/); - ghi += that->greene; - ghi = digitize(ghi, calc_depth, 1/*round*/); - - b = blo = bhi = that->bluef; - blo -= that->bluee; - blo = digitize(blo, calc_depth, 1/*round*/); - bhi += that->greene; - bhi = digitize(bhi, calc_depth, 1/*round*/); - - isgray = r==g && g==b; - - if (data.gamma != 1) - { - PNG_CONST double power = 1/data.gamma; - PNG_CONST double abse = calc_depth == 16 ? .5/65535 : .5/255; - - /* 'abse' is the absolute error permitted in linear calculations. It - * is used here to capture the error permitted in the handling - * (undoing) of the gamma encoding. Once again digitization occurs - * to handle the upper and lower bounds of the values. This is - * where the real errors are introduced. - */ - r = pow(r, power); - rlo = digitize(pow(rlo, power)-abse, calc_depth, 1); - rhi = digitize(pow(rhi, power)+abse, calc_depth, 1); - - g = pow(g, power); - glo = digitize(pow(glo, power)-abse, calc_depth, 1); - ghi = digitize(pow(ghi, power)+abse, calc_depth, 1); - - b = pow(b, power); - blo = digitize(pow(blo, power)-abse, calc_depth, 1); - bhi = digitize(pow(bhi, power)+abse, calc_depth, 1); - } - - /* Now calculate the actual gray values. Although the error in the - * coefficients depends on whether they were specified on the command - * line (in which case truncation to 15 bits happened) or not (rounding - * was used) the maxium error in an individual coefficient is always - * 1/32768, because even in the rounding case the requirement that - * coefficients add up to 32768 can cause a larger rounding error. - * - * The only time when rounding doesn't occur in 1.5.5 and later is when - * the non-gamma code path is used for less than 16 bit data. - */ - gray = r * data.red_coefficient + g * data.green_coefficient + - b * data.blue_coefficient; - - { - PNG_CONST int do_round = data.gamma != 1 || calc_depth == 16; - PNG_CONST double ce = 1. / 32768; - - graylo = digitize(rlo * (data.red_coefficient-ce) + - glo * (data.green_coefficient-ce) + - blo * (data.blue_coefficient-ce), gamma_depth, do_round); - if (graylo <= 0) - graylo = 0; - - grayhi = digitize(rhi * (data.red_coefficient+ce) + - ghi * (data.green_coefficient+ce) + - bhi * (data.blue_coefficient+ce), gamma_depth, do_round); - if (grayhi >= 1) - grayhi = 1; - } - - /* And invert the gamma. */ - if (data.gamma != 1) - { - PNG_CONST double power = data.gamma; - - gray = pow(gray, power); - graylo = digitize(pow(graylo, power), sample_depth, 1); - grayhi = digitize(pow(grayhi, power), sample_depth, 1); - } - - /* Now the error can be calculated. - * - * If r==g==b because there is no overall gamma correction libpng - * currently preserves the original value. - */ - if (isgray) - err = (that->rede + that->greene + that->bluee)/3; - - else - { - err = fabs(grayhi-gray); - if (fabs(gray - graylo) > err) - err = fabs(graylo-gray); - - /* Check that this worked: */ - if (err > pm->limit) - { - size_t pos = 0; - char buffer[128]; - - pos = safecat(buffer, sizeof buffer, pos, "rgb_to_gray error "); - pos = safecatd(buffer, sizeof buffer, pos, err, 6); - pos = safecat(buffer, sizeof buffer, pos, " exceeds limit "); - pos = safecatd(buffer, sizeof buffer, pos, pm->limit, 6); - png_error(pp, buffer); - } - } - } -# else /* DIGITIZE */ - { - double r = that->redf; - double re = that->rede; - double g = that->greenf; - double ge = that->greene; - double b = that->bluef; - double be = that->bluee; - - /* The true gray case involves no math. */ - if (r == g && r == b) - { - gray = r; - err = re; - if (err < ge) err = ge; - if (err < be) err = be; - } - - else if (data.gamma == 1) - { - /* There is no need to do the conversions to and from linear space, - * so the calculation should be a lot more accurate. There is a - * built in 1/32768 error in the coefficients because they only have - * 15 bits and are adjusted to make sure they add up to 32768, so - * the result may have an additional error up to 1/32768. (Note - * that adding the 1/32768 here avoids needing to increase the - * global error limits to take this into account.) - */ - gray = r * data.red_coefficient + g * data.green_coefficient + - b * data.blue_coefficient; - err = re * data.red_coefficient + ge * data.green_coefficient + - be * data.blue_coefficient + 1./32768 + gray * 5 * DBL_EPSILON; - } - - else - { - /* The calculation happens in linear space, and this produces much - * wider errors in the encoded space. These are handled here by - * factoring the errors in to the calculation. There are two table - * lookups in the calculation and each introduces a quantization - * error defined by the table size. - */ - PNG_CONST png_modifier *pm = display->pm; - double in_qe = (that->sample_depth > 8 ? .5/65535 : .5/255); - double out_qe = (that->sample_depth > 8 ? .5/65535 : - (pm->assume_16_bit_calculations ? .5/(1<<PNG_MAX_GAMMA_8) : - .5/255)); - double rhi, ghi, bhi, grayhi; - double g1 = 1/data.gamma; - - rhi = r + re + in_qe; if (rhi > 1) rhi = 1; - r -= re + in_qe; if (r < 0) r = 0; - ghi = g + ge + in_qe; if (ghi > 1) ghi = 1; - g -= ge + in_qe; if (g < 0) g = 0; - bhi = b + be + in_qe; if (bhi > 1) bhi = 1; - b -= be + in_qe; if (b < 0) b = 0; - - r = pow(r, g1)*(1-DBL_EPSILON); rhi = pow(rhi, g1)*(1+DBL_EPSILON); - g = pow(g, g1)*(1-DBL_EPSILON); ghi = pow(ghi, g1)*(1+DBL_EPSILON); - b = pow(b, g1)*(1-DBL_EPSILON); bhi = pow(bhi, g1)*(1+DBL_EPSILON); - - /* Work out the lower and upper bounds for the gray value in the - * encoded space, then work out an average and error. Remove the - * previously added input quantization error at this point. - */ - gray = r * data.red_coefficient + g * data.green_coefficient + - b * data.blue_coefficient - 1./32768 - out_qe; - if (gray <= 0) - gray = 0; - else - { - gray *= (1 - 6 * DBL_EPSILON); - gray = pow(gray, data.gamma) * (1-DBL_EPSILON); - } - - grayhi = rhi * data.red_coefficient + ghi * data.green_coefficient + - bhi * data.blue_coefficient + 1./32768 + out_qe; - grayhi *= (1 + 6 * DBL_EPSILON); - if (grayhi >= 1) - grayhi = 1; - else - grayhi = pow(grayhi, data.gamma) * (1+DBL_EPSILON); - - err = (grayhi - gray) / 2; - gray = (grayhi + gray) / 2; - - if (err <= in_qe) - err = gray * DBL_EPSILON; - - else - err -= in_qe; - - /* Validate that the error is within limits (this has caused - * problems before, it's much easier to detect them here.) - */ - if (err > pm->limit) - { - size_t pos = 0; - char buffer[128]; - - pos = safecat(buffer, sizeof buffer, pos, "rgb_to_gray error "); - pos = safecatd(buffer, sizeof buffer, pos, err, 6); - pos = safecat(buffer, sizeof buffer, pos, " exceeds limit "); - pos = safecatd(buffer, sizeof buffer, pos, pm->limit, 6); - png_error(pp, buffer); - } - } - } -# endif /* !DIGITIZE */ - - that->bluef = that->greenf = that->redf = gray; - that->bluee = that->greene = that->rede = err; - - /* The sBIT is the minium of the three colour channel sBITs. */ - if (that->red_sBIT > that->green_sBIT) - that->red_sBIT = that->green_sBIT; - if (that->red_sBIT > that->blue_sBIT) - that->red_sBIT = that->blue_sBIT; - that->blue_sBIT = that->green_sBIT = that->red_sBIT; - - /* And remove the colour bit in the type: */ - if (that->colour_type == PNG_COLOR_TYPE_RGB) - that->colour_type = PNG_COLOR_TYPE_GRAY; - else if (that->colour_type == PNG_COLOR_TYPE_RGB_ALPHA) - that->colour_type = PNG_COLOR_TYPE_GRAY_ALPHA; - } - - this->next->mod(this->next, that, pp, display); -} - -static int -image_transform_png_set_rgb_to_gray_add(image_transform *this, - PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth) -{ - UNUSED(bit_depth) - - this->next = *that; - *that = this; - - return (colour_type & PNG_COLOR_MASK_COLOR) != 0; -} - -#undef data -IT(rgb_to_gray); -#undef PT -#define PT ITSTRUCT(rgb_to_gray) -#undef image_transform_ini -#define image_transform_ini image_transform_default_ini -#endif /* PNG_READ_RGB_TO_GRAY_SUPPORTED */ - -#ifdef PNG_READ_BACKGROUND_SUPPORTED -/* png_set_background(png_structp, png_const_color_16p background_color, - * int background_gamma_code, int need_expand, double background_gamma) - * png_set_background_fixed(png_structp, png_const_color_16p background_color, - * int background_gamma_code, int need_expand, - * png_fixed_point background_gamma) - * - * This ignores the gamma (at present.) -*/ -#define data ITDATA(background) -static image_pixel data; - -static void -image_transform_png_set_background_set(PNG_CONST image_transform *this, - transform_display *that, png_structp pp, png_infop pi) -{ - png_byte colour_type, bit_depth; - png_byte random_bytes[8]; /* 8 bytes - 64 bits - the biggest pixel */ - int expand; - png_color_16 back; - - /* We need a background colour, because we don't know exactly what transforms - * have been set we have to supply the colour in the original file format and - * so we need to know what that is! The background colour is stored in the - * transform_display. - */ - RANDOMIZE(random_bytes); - - /* Read the random value, for colour type 3 the background colour is actually - * expressed as a 24bit rgb, not an index. - */ - colour_type = that->this.colour_type; - if (colour_type == 3) - { - colour_type = PNG_COLOR_TYPE_RGB; - bit_depth = 8; - expand = 0; /* passing in an RGB not a pixel index */ - } - - else - { - bit_depth = that->this.bit_depth; - expand = 1; - } - - image_pixel_init(&data, random_bytes, colour_type, - bit_depth, 0/*x*/, 0/*unused: palette*/, NULL/*format*/); - - /* Extract the background colour from this image_pixel, but make sure the - * unused fields of 'back' are garbage. - */ - RANDOMIZE(back); - - if (colour_type & PNG_COLOR_MASK_COLOR) - { - back.red = (png_uint_16)data.red; - back.green = (png_uint_16)data.green; - back.blue = (png_uint_16)data.blue; - } - - else - back.gray = (png_uint_16)data.red; - -# ifdef PNG_FLOATING_POINT_SUPPORTED - png_set_background(pp, &back, PNG_BACKGROUND_GAMMA_FILE, expand, 0); -# else - png_set_background_fixed(pp, &back, PNG_BACKGROUND_GAMMA_FILE, expand, 0); -# endif - - this->next->set(this->next, that, pp, pi); -} - -static void -image_transform_png_set_background_mod(PNG_CONST image_transform *this, - image_pixel *that, png_const_structp pp, - PNG_CONST transform_display *display) -{ - /* Check for tRNS first: */ - if (that->have_tRNS && that->colour_type != PNG_COLOR_TYPE_PALETTE) - image_pixel_add_alpha(that, &display->this); - - /* This is only necessary if the alpha value is less than 1. */ - if (that->alphaf < 1) - { - /* Now we do the background calculation without any gamma correction. */ - if (that->alphaf <= 0) - { - that->redf = data.redf; - that->greenf = data.greenf; - that->bluef = data.bluef; - - that->rede = data.rede; - that->greene = data.greene; - that->bluee = data.bluee; - - that->red_sBIT= data.red_sBIT; - that->green_sBIT= data.green_sBIT; - that->blue_sBIT= data.blue_sBIT; - } - - else /* 0 < alpha < 1 */ - { - double alf = 1 - that->alphaf; - - that->redf = that->redf * that->alphaf + data.redf * alf; - that->rede = that->rede * that->alphaf + data.rede * alf + - DBL_EPSILON; - that->greenf = that->greenf * that->alphaf + data.greenf * alf; - that->greene = that->greene * that->alphaf + data.greene * alf + - DBL_EPSILON; - that->bluef = that->bluef * that->alphaf + data.bluef * alf; - that->bluee = that->bluee * that->alphaf + data.bluee * alf + - DBL_EPSILON; - } - - /* Remove the alpha type and set the alpha (not in that order.) */ - that->alphaf = 1; - that->alphae = 0; - - if (that->colour_type == PNG_COLOR_TYPE_RGB_ALPHA) - that->colour_type = PNG_COLOR_TYPE_RGB; - else if (that->colour_type == PNG_COLOR_TYPE_GRAY_ALPHA) - that->colour_type = PNG_COLOR_TYPE_GRAY; - /* PNG_COLOR_TYPE_PALETTE is not changed */ - } - - this->next->mod(this->next, that, pp, display); -} - -#define image_transform_png_set_background_add image_transform_default_add - -#undef data -IT(background); -#undef PT -#define PT ITSTRUCT(background) -#endif /* PNG_READ_BACKGROUND_SUPPORTED */ - -/* png_set_quantize(png_structp, png_colorp palette, int num_palette, - * int maximum_colors, png_const_uint_16p histogram, int full_quantize) - * - * Very difficult to validate this! - */ -/*NOTE: TBD NYI */ - -/* The data layout transforms are handled by swapping our own channel data, - * necessarily these need to happen at the end of the transform list because the - * semantic of the channels changes after these are executed. Some of these, - * like set_shift and set_packing, can't be done at present because they change - * the layout of the data at the sub-sample level so sample() won't get the - * right answer. - */ -/* png_set_invert_alpha */ -#ifdef PNG_READ_INVERT_ALPHA_SUPPORTED -/* Invert the alpha channel - * - * png_set_invert_alpha(png_structrp png_ptr) - */ -static void -image_transform_png_set_invert_alpha_set(PNG_CONST image_transform *this, - transform_display *that, png_structp pp, png_infop pi) -{ - png_set_invert_alpha(pp); - this->next->set(this->next, that, pp, pi); -} - -static void -image_transform_png_set_invert_alpha_mod(PNG_CONST image_transform *this, - image_pixel *that, png_const_structp pp, - PNG_CONST transform_display *display) -{ - if (that->colour_type & 4) - that->alpha_inverted = 1; - - this->next->mod(this->next, that, pp, display); -} - -static int -image_transform_png_set_invert_alpha_add(image_transform *this, - PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth) -{ - UNUSED(bit_depth) - - this->next = *that; - *that = this; - - /* Only has an effect on pixels with alpha: */ - return (colour_type & 4) != 0; -} - -IT(invert_alpha); -#undef PT -#define PT ITSTRUCT(invert_alpha) - -#endif /* PNG_READ_INVERT_ALPHA_SUPPORTED */ - -/* png_set_bgr */ -#ifdef PNG_READ_BGR_SUPPORTED -/* Swap R,G,B channels to order B,G,R. - * - * png_set_bgr(png_structrp png_ptr) - * - * This only has an effect on RGB and RGBA pixels. - */ -static void -image_transform_png_set_bgr_set(PNG_CONST image_transform *this, - transform_display *that, png_structp pp, png_infop pi) -{ - png_set_bgr(pp); - this->next->set(this->next, that, pp, pi); -} - -static void -image_transform_png_set_bgr_mod(PNG_CONST image_transform *this, - image_pixel *that, png_const_structp pp, - PNG_CONST transform_display *display) -{ - if (that->colour_type == PNG_COLOR_TYPE_RGB || - that->colour_type == PNG_COLOR_TYPE_RGBA) - that->swap_rgb = 1; - - this->next->mod(this->next, that, pp, display); -} - -static int -image_transform_png_set_bgr_add(image_transform *this, - PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth) -{ - UNUSED(bit_depth) - - this->next = *that; - *that = this; - - return colour_type == PNG_COLOR_TYPE_RGB || - colour_type == PNG_COLOR_TYPE_RGBA; -} - -IT(bgr); -#undef PT -#define PT ITSTRUCT(bgr) - -#endif /* PNG_READ_BGR_SUPPORTED */ - -/* png_set_swap_alpha */ -#ifdef PNG_READ_SWAP_ALPHA_SUPPORTED -/* Put the alpha channel first. - * - * png_set_swap_alpha(png_structrp png_ptr) - * - * This only has an effect on GA and RGBA pixels. - */ -static void -image_transform_png_set_swap_alpha_set(PNG_CONST image_transform *this, - transform_display *that, png_structp pp, png_infop pi) -{ - png_set_swap_alpha(pp); - this->next->set(this->next, that, pp, pi); -} - -static void -image_transform_png_set_swap_alpha_mod(PNG_CONST image_transform *this, - image_pixel *that, png_const_structp pp, - PNG_CONST transform_display *display) -{ - if (that->colour_type == PNG_COLOR_TYPE_GA || - that->colour_type == PNG_COLOR_TYPE_RGBA) - that->alpha_first = 1; - - this->next->mod(this->next, that, pp, display); -} - -static int -image_transform_png_set_swap_alpha_add(image_transform *this, - PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth) -{ - UNUSED(bit_depth) - - this->next = *that; - *that = this; - - return colour_type == PNG_COLOR_TYPE_GA || - colour_type == PNG_COLOR_TYPE_RGBA; -} - -IT(swap_alpha); -#undef PT -#define PT ITSTRUCT(swap_alpha) - -#endif /* PNG_READ_SWAP_ALPHA_SUPPORTED */ - -/* png_set_swap */ -#ifdef PNG_READ_SWAP_SUPPORTED -/* Byte swap 16-bit components. - * - * png_set_swap(png_structrp png_ptr) - */ -static void -image_transform_png_set_swap_set(PNG_CONST image_transform *this, - transform_display *that, png_structp pp, png_infop pi) -{ - png_set_swap(pp); - this->next->set(this->next, that, pp, pi); -} - -static void -image_transform_png_set_swap_mod(PNG_CONST image_transform *this, - image_pixel *that, png_const_structp pp, - PNG_CONST transform_display *display) -{ - if (that->bit_depth == 16) - that->swap16 = 1; - - this->next->mod(this->next, that, pp, display); -} - -static int -image_transform_png_set_swap_add(image_transform *this, - PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth) -{ - UNUSED(colour_type) - - this->next = *that; - *that = this; - - return bit_depth == 16; -} - -IT(swap); -#undef PT -#define PT ITSTRUCT(swap) - -#endif /* PNG_READ_SWAP_SUPPORTED */ - -#ifdef PNG_READ_FILLER_SUPPORTED -/* Add a filler byte to 8-bit Gray or 24-bit RGB images. - * - * png_set_filler, (png_structp png_ptr, png_uint_32 filler, int flags)); - * - * Flags: - * - * PNG_FILLER_BEFORE - * PNG_FILLER_AFTER - */ -#define data ITDATA(filler) -static struct -{ - png_uint_32 filler; - int flags; -} data; - -static void -image_transform_png_set_filler_set(PNG_CONST image_transform *this, - transform_display *that, png_structp pp, png_infop pi) -{ - /* Need a random choice for 'before' and 'after' as well as for the - * filler. The 'filler' value has all 32 bits set, but only bit_depth - * will be used. At this point we don't know bit_depth. - */ - RANDOMIZE(data.filler); - data.flags = random_choice(); - - png_set_filler(pp, data.filler, data.flags); - - /* The standard display handling stuff also needs to know that - * there is a filler, so set that here. - */ - that->this.filler = 1; - - this->next->set(this->next, that, pp, pi); -} - -static void -image_transform_png_set_filler_mod(PNG_CONST image_transform *this, - image_pixel *that, png_const_structp pp, - PNG_CONST transform_display *display) -{ - if (that->bit_depth >= 8 && - (that->colour_type == PNG_COLOR_TYPE_RGB || - that->colour_type == PNG_COLOR_TYPE_GRAY)) - { - PNG_CONST unsigned int max = (1U << that->bit_depth)-1; - that->alpha = data.filler & max; - that->alphaf = ((double)that->alpha) / max; - that->alphae = 0; - - /* The filler has been stored in the alpha channel, we must record - * that this has been done for the checking later on, the color - * type is faked to have an alpha channel, but libpng won't report - * this; the app has to know the extra channel is there and this - * was recording in standard_display::filler above. - */ - that->colour_type |= 4; /* alpha added */ - that->alpha_first = data.flags == PNG_FILLER_BEFORE; - } - - this->next->mod(this->next, that, pp, display); -} - -static int -image_transform_png_set_filler_add(image_transform *this, - PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth) -{ - this->next = *that; - *that = this; - - return bit_depth >= 8 && (colour_type == PNG_COLOR_TYPE_RGB || - colour_type == PNG_COLOR_TYPE_GRAY); -} - -#undef data -IT(filler); -#undef PT -#define PT ITSTRUCT(filler) - -/* png_set_add_alpha, (png_structp png_ptr, png_uint_32 filler, int flags)); */ -/* Add an alpha byte to 8-bit Gray or 24-bit RGB images. */ -#define data ITDATA(add_alpha) -static struct -{ - png_uint_32 filler; - int flags; -} data; - -static void -image_transform_png_set_add_alpha_set(PNG_CONST image_transform *this, - transform_display *that, png_structp pp, png_infop pi) -{ - /* Need a random choice for 'before' and 'after' as well as for the - * filler. The 'filler' value has all 32 bits set, but only bit_depth - * will be used. At this point we don't know bit_depth. - */ - RANDOMIZE(data.filler); - data.flags = random_choice(); - - png_set_add_alpha(pp, data.filler, data.flags); - this->next->set(this->next, that, pp, pi); -} - -static void -image_transform_png_set_add_alpha_mod(PNG_CONST image_transform *this, - image_pixel *that, png_const_structp pp, - PNG_CONST transform_display *display) -{ - if (that->bit_depth >= 8 && - (that->colour_type == PNG_COLOR_TYPE_RGB || - that->colour_type == PNG_COLOR_TYPE_GRAY)) - { - PNG_CONST unsigned int max = (1U << that->bit_depth)-1; - that->alpha = data.filler & max; - that->alphaf = ((double)that->alpha) / max; - that->alphae = 0; - - that->colour_type |= 4; /* alpha added */ - that->alpha_first = data.flags == PNG_FILLER_BEFORE; - } - - this->next->mod(this->next, that, pp, display); -} - -static int -image_transform_png_set_add_alpha_add(image_transform *this, - PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth) -{ - this->next = *that; - *that = this; - - return bit_depth >= 8 && (colour_type == PNG_COLOR_TYPE_RGB || - colour_type == PNG_COLOR_TYPE_GRAY); -} - -#undef data -IT(add_alpha); -#undef PT -#define PT ITSTRUCT(add_alpha) - -#endif /* PNG_READ_FILLER_SUPPORTED */ - -/* png_set_packing */ -#ifdef PNG_READ_PACK_SUPPORTED -/* Use 1 byte per pixel in 1, 2, or 4-bit depth files. - * - * png_set_packing(png_structrp png_ptr) - * - * This should only affect grayscale and palette images with less than 8 bits - * per pixel. - */ -static void -image_transform_png_set_packing_set(PNG_CONST image_transform *this, - transform_display *that, png_structp pp, png_infop pi) -{ - png_set_packing(pp); - that->unpacked = 1; - this->next->set(this->next, that, pp, pi); -} - -static void -image_transform_png_set_packing_mod(PNG_CONST image_transform *this, - image_pixel *that, png_const_structp pp, - PNG_CONST transform_display *display) -{ - /* The general expand case depends on what the colour type is, - * low bit-depth pixel values are unpacked into bytes without - * scaling, so sample_depth is not changed. - */ - if (that->bit_depth < 8) /* grayscale or palette */ - that->bit_depth = 8; - - this->next->mod(this->next, that, pp, display); -} - -static int -image_transform_png_set_packing_add(image_transform *this, - PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth) -{ - UNUSED(colour_type) - - this->next = *that; - *that = this; - - /* Nothing should happen unless the bit depth is less than 8: */ - return bit_depth < 8; -} - -IT(packing); -#undef PT -#define PT ITSTRUCT(packing) - -#endif /* PNG_READ_PACK_SUPPORTED */ - -/* png_set_packswap */ -#ifdef PNG_READ_PACKSWAP_SUPPORTED -/* Swap pixels packed into bytes; reverses the order on screen so that - * the high order bits correspond to the rightmost pixels. - * - * png_set_packswap(png_structrp png_ptr) - */ -static void -image_transform_png_set_packswap_set(PNG_CONST image_transform *this, - transform_display *that, png_structp pp, png_infop pi) -{ - png_set_packswap(pp); - this->next->set(this->next, that, pp, pi); -} - -static void -image_transform_png_set_packswap_mod(PNG_CONST image_transform *this, - image_pixel *that, png_const_structp pp, - PNG_CONST transform_display *display) -{ - if (that->bit_depth < 8) - that->littleendian = 1; - - this->next->mod(this->next, that, pp, display); -} - -static int -image_transform_png_set_packswap_add(image_transform *this, - PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth) -{ - UNUSED(colour_type) - - this->next = *that; - *that = this; - - return bit_depth < 8; -} - -IT(packswap); -#undef PT -#define PT ITSTRUCT(packswap) - -#endif /* PNG_READ_PACKSWAP_SUPPORTED */ - - -/* png_set_invert_mono */ -#ifdef PNG_READ_INVERT_MONO_SUPPORTED -/* Invert the gray channel - * - * png_set_invert_mono(png_structrp png_ptr) - */ -static void -image_transform_png_set_invert_mono_set(PNG_CONST image_transform *this, - transform_display *that, png_structp pp, png_infop pi) -{ - png_set_invert_mono(pp); - this->next->set(this->next, that, pp, pi); -} - -static void -image_transform_png_set_invert_mono_mod(PNG_CONST image_transform *this, - image_pixel *that, png_const_structp pp, - PNG_CONST transform_display *display) -{ - if (that->colour_type & 4) - that->mono_inverted = 1; - - this->next->mod(this->next, that, pp, display); -} - -static int -image_transform_png_set_invert_mono_add(image_transform *this, - PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth) -{ - UNUSED(bit_depth) - - this->next = *that; - *that = this; - - /* Only has an effect on pixels with no colour: */ - return (colour_type & 2) == 0; -} - -IT(invert_mono); -#undef PT -#define PT ITSTRUCT(invert_mono) - -#endif /* PNG_READ_INVERT_MONO_SUPPORTED */ - -#ifdef PNG_READ_SHIFT_SUPPORTED -/* png_set_shift(png_structp, png_const_color_8p true_bits) - * - * The output pixels will be shifted by the given true_bits - * values. - */ -#define data ITDATA(shift) -static png_color_8 data; - -static void -image_transform_png_set_shift_set(PNG_CONST image_transform *this, - transform_display *that, png_structp pp, png_infop pi) -{ - /* Get a random set of shifts. The shifts need to do something - * to test the transform, so they are limited to the bit depth - * of the input image. Notice that in the following the 'gray' - * field is randomized independently. This acts as a check that - * libpng does use the correct field. - */ - PNG_CONST unsigned int depth = that->this.bit_depth; - - data.red = (png_byte)/*SAFE*/(random_mod(depth)+1); - data.green = (png_byte)/*SAFE*/(random_mod(depth)+1); - data.blue = (png_byte)/*SAFE*/(random_mod(depth)+1); - data.gray = (png_byte)/*SAFE*/(random_mod(depth)+1); - data.alpha = (png_byte)/*SAFE*/(random_mod(depth)+1); - - png_set_shift(pp, &data); - this->next->set(this->next, that, pp, pi); -} - -static void -image_transform_png_set_shift_mod(PNG_CONST image_transform *this, - image_pixel *that, png_const_structp pp, - PNG_CONST transform_display *display) -{ - /* Copy the correct values into the sBIT fields, libpng does not do - * anything to palette data: - */ - if (that->colour_type != PNG_COLOR_TYPE_PALETTE) - { - that->sig_bits = 1; - - /* The sBIT fields are reset to the values previously sent to - * png_set_shift according to the colour type. - * does. - */ - if (that->colour_type & 2) /* RGB channels */ - { - that->red_sBIT = data.red; - that->green_sBIT = data.green; - that->blue_sBIT = data.blue; - } - - else /* One grey channel */ - that->red_sBIT = that->green_sBIT = that->blue_sBIT = data.gray; - - that->alpha_sBIT = data.alpha; - } - - this->next->mod(this->next, that, pp, display); -} - -static int -image_transform_png_set_shift_add(image_transform *this, - PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth) -{ - UNUSED(bit_depth) - - this->next = *that; - *that = this; - - return colour_type != PNG_COLOR_TYPE_PALETTE; -} - -IT(shift); -#undef PT -#define PT ITSTRUCT(shift) - -#endif /* PNG_READ_SHIFT_SUPPORTED */ - -#ifdef THIS_IS_THE_PROFORMA -static void -image_transform_png_set_@_set(PNG_CONST image_transform *this, - transform_display *that, png_structp pp, png_infop pi) -{ - png_set_@(pp); - this->next->set(this->next, that, pp, pi); -} - -static void -image_transform_png_set_@_mod(PNG_CONST image_transform *this, - image_pixel *that, png_const_structp pp, - PNG_CONST transform_display *display) -{ - this->next->mod(this->next, that, pp, display); -} - -static int -image_transform_png_set_@_add(image_transform *this, - PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth) -{ - this->next = *that; - *that = this; - - return 1; -} - -IT(@); -#endif - - -/* This may just be 'end' if all the transforms are disabled! */ -static image_transform *PNG_CONST image_transform_first = &PT; - -static void -transform_enable(PNG_CONST char *name) -{ - /* Everything starts out enabled, so if we see an 'enable' disabled - * everything else the first time round. - */ - static int all_disabled = 0; - int found_it = 0; - image_transform *list = image_transform_first; - - while (list != &image_transform_end) - { - if (strcmp(list->name, name) == 0) - { - list->enable = 1; - found_it = 1; - } - else if (!all_disabled) - list->enable = 0; - - list = list->list; - } - - all_disabled = 1; - - if (!found_it) - { - fprintf(stderr, "pngvalid: --transform-enable=%s: unknown transform\n", - name); - exit(99); - } -} - -static void -transform_disable(PNG_CONST char *name) -{ - image_transform *list = image_transform_first; - - while (list != &image_transform_end) - { - if (strcmp(list->name, name) == 0) - { - list->enable = 0; - return; - } - - list = list->list; - } - - fprintf(stderr, "pngvalid: --transform-disable=%s: unknown transform\n", - name); - exit(99); -} - -static void -image_transform_reset_count(void) -{ - image_transform *next = image_transform_first; - int count = 0; - - while (next != &image_transform_end) - { - next->local_use = 0; - next->next = 0; - next = next->list; - ++count; - } - - /* This can only happen if we every have more than 32 transforms (excluding - * the end) in the list. - */ - if (count > 32) abort(); -} - -static int -image_transform_test_counter(png_uint_32 counter, unsigned int max) -{ - /* Test the list to see if there is any point contining, given a current - * counter and a 'max' value. - */ - image_transform *next = image_transform_first; - - while (next != &image_transform_end) - { - /* For max 0 or 1 continue until the counter overflows: */ - counter >>= 1; - - /* Continue if any entry hasn't reacked the max. */ - if (max > 1 && next->local_use < max) - return 1; - next = next->list; - } - - return max <= 1 && counter == 0; -} - -static png_uint_32 -image_transform_add(PNG_CONST image_transform **this, unsigned int max, - png_uint_32 counter, char *name, size_t sizeof_name, size_t *pos, - png_byte colour_type, png_byte bit_depth) -{ - for (;;) /* until we manage to add something */ - { - png_uint_32 mask; - image_transform *list; - - /* Find the next counter value, if the counter is zero this is the start - * of the list. This routine always returns the current counter (not the - * next) so it returns 0 at the end and expects 0 at the beginning. - */ - if (counter == 0) /* first time */ - { - image_transform_reset_count(); - if (max <= 1) - counter = 1; - else - counter = random_32(); - } - else /* advance the counter */ - { - switch (max) - { - case 0: ++counter; break; - case 1: counter <<= 1; break; - default: counter = random_32(); break; - } - } - - /* Now add all these items, if possible */ - *this = &image_transform_end; - list = image_transform_first; - mask = 1; - - /* Go through the whole list adding anything that the counter selects: */ - while (list != &image_transform_end) - { - if ((counter & mask) != 0 && list->enable && - (max == 0 || list->local_use < max)) - { - /* Candidate to add: */ - if (list->add(list, this, colour_type, bit_depth) || max == 0) - { - /* Added, so add to the name too. */ - *pos = safecat(name, sizeof_name, *pos, " +"); - *pos = safecat(name, sizeof_name, *pos, list->name); - } - - else - { - /* Not useful and max>0, so remove it from *this: */ - *this = list->next; - list->next = 0; - - /* And, since we know it isn't useful, stop it being added again - * in this run: - */ - list->local_use = max; - } - } - - mask <<= 1; - list = list->list; - } - - /* Now if anything was added we have something to do. */ - if (*this != &image_transform_end) - return counter; - - /* Nothing added, but was there anything in there to add? */ - if (!image_transform_test_counter(counter, max)) - return 0; - } -} - -static void -perform_transform_test(png_modifier *pm) -{ - png_byte colour_type = 0; - png_byte bit_depth = 0; - unsigned int palette_number = 0; - - while (next_format(&colour_type, &bit_depth, &palette_number, 0)) - { - png_uint_32 counter = 0; - size_t base_pos; - char name[64]; - - base_pos = safecat(name, sizeof name, 0, "transform:"); - - for (;;) - { - size_t pos = base_pos; - PNG_CONST image_transform *list = 0; - - /* 'max' is currently hardwired to '1'; this should be settable on the - * command line. - */ - counter = image_transform_add(&list, 1/*max*/, counter, - name, sizeof name, &pos, colour_type, bit_depth); - - if (counter == 0) - break; - - /* The command line can change this to checking interlaced images. */ - do - { - pm->repeat = 0; - transform_test(pm, FILEID(colour_type, bit_depth, palette_number, - pm->interlace_type, 0, 0, 0), list, name); - - if (fail(pm)) - return; - } - while (pm->repeat); - } - } -} -#endif /* PNG_READ_TRANSFORMS_SUPPORTED */ - -/********************************* GAMMA TESTS ********************************/ -#ifdef PNG_READ_GAMMA_SUPPORTED -/* Reader callbacks and implementations, where they differ from the standard - * ones. - */ -typedef struct gamma_display -{ - standard_display this; - - /* Parameters */ - png_modifier* pm; - double file_gamma; - double screen_gamma; - double background_gamma; - png_byte sbit; - int threshold_test; - int use_input_precision; - int scale16; - int expand16; - int do_background; - png_color_16 background_color; - - /* Local variables */ - double maxerrout; - double maxerrpc; - double maxerrabs; -} gamma_display; - -#define ALPHA_MODE_OFFSET 4 - -static void -gamma_display_init(gamma_display *dp, png_modifier *pm, png_uint_32 id, - double file_gamma, double screen_gamma, png_byte sbit, int threshold_test, - int use_input_precision, int scale16, int expand16, - int do_background, PNG_CONST png_color_16 *pointer_to_the_background_color, - double background_gamma) -{ - /* Standard fields */ - standard_display_init(&dp->this, &pm->this, id, 0/*do_interlace*/, - pm->use_update_info); - - /* Parameter fields */ - dp->pm = pm; - dp->file_gamma = file_gamma; - dp->screen_gamma = screen_gamma; - dp->background_gamma = background_gamma; - dp->sbit = sbit; - dp->threshold_test = threshold_test; - dp->use_input_precision = use_input_precision; - dp->scale16 = scale16; - dp->expand16 = expand16; - dp->do_background = do_background; - if (do_background && pointer_to_the_background_color != 0) - dp->background_color = *pointer_to_the_background_color; - else - memset(&dp->background_color, 0, sizeof dp->background_color); - - /* Local variable fields */ - dp->maxerrout = dp->maxerrpc = dp->maxerrabs = 0; -} - -static void -gamma_info_imp(gamma_display *dp, png_structp pp, png_infop pi) -{ - /* Reuse the standard stuff as appropriate. */ - standard_info_part1(&dp->this, pp, pi); - - /* If requested strip 16 to 8 bits - this is handled automagically below - * because the output bit depth is read from the library. Note that there - * are interactions with sBIT but, internally, libpng makes sbit at most - * PNG_MAX_GAMMA_8 when doing the following. - */ - if (dp->scale16) -# ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED - png_set_scale_16(pp); -# else - /* The following works both in 1.5.4 and earlier versions: */ -# ifdef PNG_READ_16_TO_8_SUPPORTED - png_set_strip_16(pp); -# else - png_error(pp, "scale16 (16 to 8 bit conversion) not supported"); -# endif -# endif - - if (dp->expand16) -# ifdef PNG_READ_EXPAND_16_SUPPORTED - png_set_expand_16(pp); -# else - png_error(pp, "expand16 (8 to 16 bit conversion) not supported"); -# endif - - if (dp->do_background >= ALPHA_MODE_OFFSET) - { -# ifdef PNG_READ_ALPHA_MODE_SUPPORTED - { - /* This tests the alpha mode handling, if supported. */ - int mode = dp->do_background - ALPHA_MODE_OFFSET; - - /* The gamma value is the output gamma, and is in the standard, - * non-inverted, represenation. It provides a default for the PNG file - * gamma, but since the file has a gAMA chunk this does not matter. - */ - PNG_CONST double sg = dp->screen_gamma; -# ifndef PNG_FLOATING_POINT_SUPPORTED - PNG_CONST png_fixed_point g = fix(sg); -# endif - -# ifdef PNG_FLOATING_POINT_SUPPORTED - png_set_alpha_mode(pp, mode, sg); -# else - png_set_alpha_mode_fixed(pp, mode, g); -# endif - - /* However, for the standard Porter-Duff algorithm the output defaults - * to be linear, so if the test requires non-linear output it must be - * corrected here. - */ - if (mode == PNG_ALPHA_STANDARD && sg != 1) - { -# ifdef PNG_FLOATING_POINT_SUPPORTED - png_set_gamma(pp, sg, dp->file_gamma); -# else - png_fixed_point f = fix(dp->file_gamma); - png_set_gamma_fixed(pp, g, f); -# endif - } - } -# else - png_error(pp, "alpha mode handling not supported"); -# endif - } - - else - { - /* Set up gamma processing. */ -# ifdef PNG_FLOATING_POINT_SUPPORTED - png_set_gamma(pp, dp->screen_gamma, dp->file_gamma); -# else - { - png_fixed_point s = fix(dp->screen_gamma); - png_fixed_point f = fix(dp->file_gamma); - png_set_gamma_fixed(pp, s, f); - } -# endif - - if (dp->do_background) - { -# ifdef PNG_READ_BACKGROUND_SUPPORTED - /* NOTE: this assumes the caller provided the correct background gamma! - */ - PNG_CONST double bg = dp->background_gamma; -# ifndef PNG_FLOATING_POINT_SUPPORTED - PNG_CONST png_fixed_point g = fix(bg); -# endif - -# ifdef PNG_FLOATING_POINT_SUPPORTED - png_set_background(pp, &dp->background_color, dp->do_background, - 0/*need_expand*/, bg); -# else - png_set_background_fixed(pp, &dp->background_color, - dp->do_background, 0/*need_expand*/, g); -# endif -# else - png_error(pp, "png_set_background not supported"); -# endif - } - } - - { - int i = dp->this.use_update_info; - /* Always do one call, even if use_update_info is 0. */ - do - png_read_update_info(pp, pi); - while (--i > 0); - } - - /* Now we may get a different cbRow: */ - standard_info_part2(&dp->this, pp, pi, 1 /*images*/); -} - -static void PNGCBAPI -gamma_info(png_structp pp, png_infop pi) -{ - gamma_info_imp(voidcast(gamma_display*, png_get_progressive_ptr(pp)), pp, - pi); -} - -/* Validate a single component value - the routine gets the input and output - * sample values as unscaled PNG component values along with a cache of all the - * information required to validate the values. - */ -typedef struct validate_info -{ - png_const_structp pp; - gamma_display *dp; - png_byte sbit; - int use_input_precision; - int do_background; - int scale16; - unsigned int sbit_max; - unsigned int isbit_shift; - unsigned int outmax; - - double gamma_correction; /* Overall correction required. */ - double file_inverse; /* Inverse of file gamma. */ - double screen_gamma; - double screen_inverse; /* Inverse of screen gamma. */ - - double background_red; /* Linear background value, red or gray. */ - double background_green; - double background_blue; - - double maxabs; - double maxpc; - double maxcalc; - double maxout; - double maxout_total; /* Total including quantization error */ - double outlog; - int outquant; -} -validate_info; - -static void -init_validate_info(validate_info *vi, gamma_display *dp, png_const_structp pp, - int in_depth, int out_depth) -{ - PNG_CONST unsigned int outmax = (1U<<out_depth)-1; - - vi->pp = pp; - vi->dp = dp; - - if (dp->sbit > 0 && dp->sbit < in_depth) - { - vi->sbit = dp->sbit; - vi->isbit_shift = in_depth - dp->sbit; - } - - else - { - vi->sbit = (png_byte)in_depth; - vi->isbit_shift = 0; - } - - vi->sbit_max = (1U << vi->sbit)-1; - - /* This mimics the libpng threshold test, '0' is used to prevent gamma - * correction in the validation test. - */ - vi->screen_gamma = dp->screen_gamma; - if (fabs(vi->screen_gamma-1) < PNG_GAMMA_THRESHOLD) - vi->screen_gamma = vi->screen_inverse = 0; - else - vi->screen_inverse = 1/vi->screen_gamma; - - vi->use_input_precision = dp->use_input_precision; - vi->outmax = outmax; - vi->maxabs = abserr(dp->pm, in_depth, out_depth); - vi->maxpc = pcerr(dp->pm, in_depth, out_depth); - vi->maxcalc = calcerr(dp->pm, in_depth, out_depth); - vi->maxout = outerr(dp->pm, in_depth, out_depth); - vi->outquant = output_quantization_factor(dp->pm, in_depth, out_depth); - vi->maxout_total = vi->maxout + vi->outquant * .5; - vi->outlog = outlog(dp->pm, in_depth, out_depth); - - if ((dp->this.colour_type & PNG_COLOR_MASK_ALPHA) != 0 || - (dp->this.colour_type == 3 && dp->this.is_transparent)) - { - vi->do_background = dp->do_background; - - if (vi->do_background != 0) - { - PNG_CONST double bg_inverse = 1/dp->background_gamma; - double r, g, b; - - /* Caller must at least put the gray value into the red channel */ - r = dp->background_color.red; r /= outmax; - g = dp->background_color.green; g /= outmax; - b = dp->background_color.blue; b /= outmax; - -# if 0 - /* libpng doesn't do this optimization, if we do pngvalid will fail. - */ - if (fabs(bg_inverse-1) >= PNG_GAMMA_THRESHOLD) -# endif - { - r = pow(r, bg_inverse); - g = pow(g, bg_inverse); - b = pow(b, bg_inverse); - } - - vi->background_red = r; - vi->background_green = g; - vi->background_blue = b; - } - } - else - vi->do_background = 0; - - if (vi->do_background == 0) - vi->background_red = vi->background_green = vi->background_blue = 0; - - vi->gamma_correction = 1/(dp->file_gamma*dp->screen_gamma); - if (fabs(vi->gamma_correction-1) < PNG_GAMMA_THRESHOLD) - vi->gamma_correction = 0; - - vi->file_inverse = 1/dp->file_gamma; - if (fabs(vi->file_inverse-1) < PNG_GAMMA_THRESHOLD) - vi->file_inverse = 0; - - vi->scale16 = dp->scale16; -} - -/* This function handles composition of a single non-alpha component. The - * argument is the input sample value, in the range 0..1, and the alpha value. - * The result is the composed, linear, input sample. If alpha is less than zero - * this is the alpha component and the function should not be called! - */ -static double -gamma_component_compose(int do_background, double input_sample, double alpha, - double background, int *compose) -{ - switch (do_background) - { -#ifdef PNG_READ_BACKGROUND_SUPPORTED - case PNG_BACKGROUND_GAMMA_SCREEN: - case PNG_BACKGROUND_GAMMA_FILE: - case PNG_BACKGROUND_GAMMA_UNIQUE: - /* Standard PNG background processing. */ - if (alpha < 1) - { - if (alpha > 0) - { - input_sample = input_sample * alpha + background * (1-alpha); - if (compose != NULL) - *compose = 1; - } - - else - input_sample = background; - } - break; -#endif - -#ifdef PNG_READ_ALPHA_MODE_SUPPORTED - case ALPHA_MODE_OFFSET + PNG_ALPHA_STANDARD: - case ALPHA_MODE_OFFSET + PNG_ALPHA_BROKEN: - /* The components are premultiplied in either case and the output is - * gamma encoded (to get standard Porter-Duff we expect the output - * gamma to be set to 1.0!) - */ - case ALPHA_MODE_OFFSET + PNG_ALPHA_OPTIMIZED: - /* The optimization is that the partial-alpha entries are linear - * while the opaque pixels are gamma encoded, but this only affects the - * output encoding. - */ - if (alpha < 1) - { - if (alpha > 0) - { - input_sample *= alpha; - if (compose != NULL) - *compose = 1; - } - - else - input_sample = 0; - } - break; -#endif - - default: - /* Standard cases where no compositing is done (so the component - * value is already correct.) - */ - UNUSED(alpha) - UNUSED(background) - UNUSED(compose) - break; - } - - return input_sample; -} - -/* This API returns the encoded *input* component, in the range 0..1 */ -static double -gamma_component_validate(PNG_CONST char *name, PNG_CONST validate_info *vi, - PNG_CONST unsigned int id, PNG_CONST unsigned int od, - PNG_CONST double alpha /* <0 for the alpha channel itself */, - PNG_CONST double background /* component background value */) -{ - PNG_CONST unsigned int isbit = id >> vi->isbit_shift; - PNG_CONST unsigned int sbit_max = vi->sbit_max; - PNG_CONST unsigned int outmax = vi->outmax; - PNG_CONST int do_background = vi->do_background; - - double i; - - /* First check on the 'perfect' result obtained from the digitized input - * value, id, and compare this against the actual digitized result, 'od'. - * 'i' is the input result in the range 0..1: - */ - i = isbit; i /= sbit_max; - - /* Check for the fast route: if we don't do any background composition or if - * this is the alpha channel ('alpha' < 0) or if the pixel is opaque then - * just use the gamma_correction field to correct to the final output gamma. - */ - if (alpha == 1 /* opaque pixel component */ || !do_background -#ifdef PNG_READ_ALPHA_MODE_SUPPORTED - || do_background == ALPHA_MODE_OFFSET + PNG_ALPHA_PNG -#endif - || (alpha < 0 /* alpha channel */ -#ifdef PNG_READ_ALPHA_MODE_SUPPORTED - && do_background != ALPHA_MODE_OFFSET + PNG_ALPHA_BROKEN -#endif - )) - { - /* Then get the gamma corrected version of 'i' and compare to 'od', any - * error less than .5 is insignificant - just quantization of the output - * value to the nearest digital value (nevertheless the error is still - * recorded - it's interesting ;-) - */ - double encoded_sample = i; - double encoded_error; - - /* alpha less than 0 indicates the alpha channel, which is always linear - */ - if (alpha >= 0 && vi->gamma_correction > 0) - encoded_sample = pow(encoded_sample, vi->gamma_correction); - encoded_sample *= outmax; - - encoded_error = fabs(od-encoded_sample); - - if (encoded_error > vi->dp->maxerrout) - vi->dp->maxerrout = encoded_error; - - if (encoded_error < vi->maxout_total && encoded_error < vi->outlog) - return i; - } - - /* The slow route - attempt to do linear calculations. */ - /* There may be an error, or background processing is required, so calculate - * the actual sample values - unencoded light intensity values. Note that in - * practice these are not completely unencoded because they include a - * 'viewing correction' to decrease or (normally) increase the perceptual - * contrast of the image. There's nothing we can do about this - we don't - * know what it is - so assume the unencoded value is perceptually linear. - */ - { - double input_sample = i; /* In range 0..1 */ - double output, error, encoded_sample, encoded_error; - double es_lo, es_hi; - int compose = 0; /* Set to one if composition done */ - int output_is_encoded; /* Set if encoded to screen gamma */ - int log_max_error = 1; /* Check maximum error values */ - png_const_charp pass = 0; /* Reason test passes (or 0 for fail) */ - - /* Convert to linear light (with the above caveat.) The alpha channel is - * already linear. - */ - if (alpha >= 0) - { - int tcompose; - - if (vi->file_inverse > 0) - input_sample = pow(input_sample, vi->file_inverse); - - /* Handle the compose processing: */ - tcompose = 0; - input_sample = gamma_component_compose(do_background, input_sample, - alpha, background, &tcompose); - - if (tcompose) - compose = 1; - } - - /* And similarly for the output value, but we need to check the background - * handling to linearize it correctly. - */ - output = od; - output /= outmax; - - output_is_encoded = vi->screen_gamma > 0; - - if (alpha < 0) /* The alpha channel */ - { -#ifdef PNG_READ_ALPHA_MODE_SUPPORTED - if (do_background != ALPHA_MODE_OFFSET + PNG_ALPHA_BROKEN) -#endif - { - /* In all other cases the output alpha channel is linear already, - * don't log errors here, they are much larger in linear data. - */ - output_is_encoded = 0; - log_max_error = 0; - } - } - -#ifdef PNG_READ_ALPHA_MODE_SUPPORTED - else /* A component */ - { - if (do_background == ALPHA_MODE_OFFSET + PNG_ALPHA_OPTIMIZED && - alpha < 1) /* the optimized case - linear output */ - { - if (alpha > 0) log_max_error = 0; - output_is_encoded = 0; - } - } -#endif - - if (output_is_encoded) - output = pow(output, vi->screen_gamma); - - /* Calculate (or recalculate) the encoded_sample value and repeat the - * check above (unnecessary if we took the fast route, but harmless.) - */ - encoded_sample = input_sample; - if (output_is_encoded) - encoded_sample = pow(encoded_sample, vi->screen_inverse); - encoded_sample *= outmax; - - encoded_error = fabs(od-encoded_sample); - - /* Don't log errors in the alpha channel, or the 'optimized' case, - * neither are significant to the overall perception. - */ - if (log_max_error && encoded_error > vi->dp->maxerrout) - vi->dp->maxerrout = encoded_error; - - if (encoded_error < vi->maxout_total) - { - if (encoded_error < vi->outlog) - return i; - - /* Test passed but error is bigger than the log limit, record why the - * test passed: - */ - pass = "less than maxout:\n"; - } - - /* i: the original input value in the range 0..1 - * - * pngvalid calculations: - * input_sample: linear result; i linearized and composed, range 0..1 - * encoded_sample: encoded result; input_sample scaled to ouput bit depth - * - * libpng calculations: - * output: linear result; od scaled to 0..1 and linearized - * od: encoded result from libpng - */ - - /* Now we have the numbers for real errors, both absolute values as as a - * percentage of the correct value (output): - */ - error = fabs(input_sample-output); - - if (log_max_error && error > vi->dp->maxerrabs) - vi->dp->maxerrabs = error; - - /* The following is an attempt to ignore the tendency of quantization to - * dominate the percentage errors for lower result values: - */ - if (log_max_error && input_sample > .5) - { - double percentage_error = error/input_sample; - if (percentage_error > vi->dp->maxerrpc) - vi->dp->maxerrpc = percentage_error; - } - - /* Now calculate the digitization limits for 'encoded_sample' using the - * 'max' values. Note that maxout is in the encoded space but maxpc and - * maxabs are in linear light space. - * - * First find the maximum error in linear light space, range 0..1: - */ - { - double tmp = input_sample * vi->maxpc; - if (tmp < vi->maxabs) tmp = vi->maxabs; - /* If 'compose' is true the composition was done in linear space using - * integer arithmetic. This introduces an extra error of +/- 0.5 (at - * least) in the integer space used. 'maxcalc' records this, taking - * into account the possibility that even for 16 bit output 8 bit space - * may have been used. - */ - if (compose && tmp < vi->maxcalc) tmp = vi->maxcalc; - - /* The 'maxout' value refers to the encoded result, to compare with - * this encode input_sample adjusted by the maximum error (tmp) above. - */ - es_lo = encoded_sample - vi->maxout; - - if (es_lo > 0 && input_sample-tmp > 0) - { - double low_value = input_sample-tmp; - if (output_is_encoded) - low_value = pow(low_value, vi->screen_inverse); - low_value *= outmax; - if (low_value < es_lo) es_lo = low_value; - - /* Quantize this appropriately: */ - es_lo = ceil(es_lo / vi->outquant - .5) * vi->outquant; - } - - else - es_lo = 0; - - es_hi = encoded_sample + vi->maxout; - - if (es_hi < outmax && input_sample+tmp < 1) - { - double high_value = input_sample+tmp; - if (output_is_encoded) - high_value = pow(high_value, vi->screen_inverse); - high_value *= outmax; - if (high_value > es_hi) es_hi = high_value; - - es_hi = floor(es_hi / vi->outquant + .5) * vi->outquant; - } - - else - es_hi = outmax; - } - - /* The primary test is that the final encoded value returned by the - * library should be between the two limits (inclusive) that were - * calculated above. - */ - if (od >= es_lo && od <= es_hi) - { - /* The value passes, but we may need to log the information anyway. */ - if (encoded_error < vi->outlog) - return i; - - if (pass == 0) - pass = "within digitization limits:\n"; - } - - { - /* There has been an error in processing, or we need to log this - * value. - */ - double is_lo, is_hi; - - /* pass is set at this point if either of the tests above would have - * passed. Don't do these additional tests here - just log the - * original [es_lo..es_hi] values. - */ - if (pass == 0 && vi->use_input_precision && vi->dp->sbit) - { - /* Ok, something is wrong - this actually happens in current libpng - * 16-to-8 processing. Assume that the input value (id, adjusted - * for sbit) can be anywhere between value-.5 and value+.5 - quite a - * large range if sbit is low. - * - * NOTE: at present because the libpng gamma table stuff has been - * changed to use a rounding algorithm to correct errors in 8-bit - * calculations the precise sbit calculation (a shift) has been - * lost. This can result in up to a +/-1 error in the presence of - * an sbit less than the bit depth. - */ -# if PNG_LIBPNG_VER < 10700 -# define SBIT_ERROR .5 -# else -# define SBIT_ERROR 1. -# endif - double tmp = (isbit - SBIT_ERROR)/sbit_max; - - if (tmp <= 0) - tmp = 0; - - else if (alpha >= 0 && vi->file_inverse > 0 && tmp < 1) - tmp = pow(tmp, vi->file_inverse); - - tmp = gamma_component_compose(do_background, tmp, alpha, background, - NULL); - - if (output_is_encoded && tmp > 0 && tmp < 1) - tmp = pow(tmp, vi->screen_inverse); - - is_lo = ceil(outmax * tmp - vi->maxout_total); - - if (is_lo < 0) - is_lo = 0; - - tmp = (isbit + SBIT_ERROR)/sbit_max; - - if (tmp >= 1) - tmp = 1; - - else if (alpha >= 0 && vi->file_inverse > 0 && tmp < 1) - tmp = pow(tmp, vi->file_inverse); - - tmp = gamma_component_compose(do_background, tmp, alpha, background, - NULL); - - if (output_is_encoded && tmp > 0 && tmp < 1) - tmp = pow(tmp, vi->screen_inverse); - - is_hi = floor(outmax * tmp + vi->maxout_total); - - if (is_hi > outmax) - is_hi = outmax; - - if (!(od < is_lo || od > is_hi)) - { - if (encoded_error < vi->outlog) - return i; - - pass = "within input precision limits:\n"; - } - - /* One last chance. If this is an alpha channel and the 16to8 - * option has been used and 'inaccurate' scaling is used then the - * bit reduction is obtained by simply using the top 8 bits of the - * value. - * - * This is only done for older libpng versions when the 'inaccurate' - * (chop) method of scaling was used. - */ -# ifndef PNG_READ_16_TO_8_ACCURATE_SCALE_SUPPORTED -# if PNG_LIBPNG_VER < 10504 - /* This may be required for other components in the future, - * but at present the presence of gamma correction effectively - * prevents the errors in the component scaling (I don't quite - * understand why, but since it's better this way I care not - * to ask, JB 20110419.) - */ - if (pass == 0 && alpha < 0 && vi->scale16 && vi->sbit > 8 && - vi->sbit + vi->isbit_shift == 16) - { - tmp = ((id >> 8) - .5)/255; - - if (tmp > 0) - { - is_lo = ceil(outmax * tmp - vi->maxout_total); - if (is_lo < 0) is_lo = 0; - } - - else - is_lo = 0; - - tmp = ((id >> 8) + .5)/255; - - if (tmp < 1) - { - is_hi = floor(outmax * tmp + vi->maxout_total); - if (is_hi > outmax) is_hi = outmax; - } - - else - is_hi = outmax; - - if (!(od < is_lo || od > is_hi)) - { - if (encoded_error < vi->outlog) - return i; - - pass = "within 8 bit limits:\n"; - } - } -# endif -# endif - } - else /* !use_input_precision */ - is_lo = es_lo, is_hi = es_hi; - - /* Attempt to output a meaningful error/warning message: the message - * output depends on the background/composite operation being performed - * because this changes what parameters were actually used above. - */ - { - size_t pos = 0; - /* Need either 1/255 or 1/65535 precision here; 3 or 6 decimal - * places. Just use outmax to work out which. - */ - int precision = (outmax >= 1000 ? 6 : 3); - int use_input=1, use_background=0, do_compose=0; - char msg[256]; - - if (pass != 0) - pos = safecat(msg, sizeof msg, pos, "\n\t"); - - /* Set up the various flags, the output_is_encoded flag above - * is also used below. do_compose is just a double check. - */ - switch (do_background) - { -# ifdef PNG_READ_BACKGROUND_SUPPORTED - case PNG_BACKGROUND_GAMMA_SCREEN: - case PNG_BACKGROUND_GAMMA_FILE: - case PNG_BACKGROUND_GAMMA_UNIQUE: - use_background = (alpha >= 0 && alpha < 1); - /*FALL THROUGH*/ -# endif -# ifdef PNG_READ_ALPHA_MODE_SUPPORTED - case ALPHA_MODE_OFFSET + PNG_ALPHA_STANDARD: - case ALPHA_MODE_OFFSET + PNG_ALPHA_BROKEN: - case ALPHA_MODE_OFFSET + PNG_ALPHA_OPTIMIZED: -# endif /* ALPHA_MODE_SUPPORTED */ - do_compose = (alpha > 0 && alpha < 1); - use_input = (alpha != 0); - break; - - default: - break; - } - - /* Check the 'compose' flag */ - if (compose != do_compose) - png_error(vi->pp, "internal error (compose)"); - - /* 'name' is the component name */ - pos = safecat(msg, sizeof msg, pos, name); - pos = safecat(msg, sizeof msg, pos, "("); - pos = safecatn(msg, sizeof msg, pos, id); - if (use_input || pass != 0/*logging*/) - { - if (isbit != id) - { - /* sBIT has reduced the precision of the input: */ - pos = safecat(msg, sizeof msg, pos, ", sbit("); - pos = safecatn(msg, sizeof msg, pos, vi->sbit); - pos = safecat(msg, sizeof msg, pos, "): "); - pos = safecatn(msg, sizeof msg, pos, isbit); - } - pos = safecat(msg, sizeof msg, pos, "/"); - /* The output is either "id/max" or "id sbit(sbit): isbit/max" */ - pos = safecatn(msg, sizeof msg, pos, vi->sbit_max); - } - pos = safecat(msg, sizeof msg, pos, ")"); - - /* A component may have been multiplied (in linear space) by the - * alpha value, 'compose' says whether this is relevant. - */ - if (compose || pass != 0) - { - /* If any form of composition is being done report our - * calculated linear value here (the code above doesn't record - * the input value before composition is performed, so what - * gets reported is the value after composition.) - */ - if (use_input || pass != 0) - { - if (vi->file_inverse > 0) - { - pos = safecat(msg, sizeof msg, pos, "^"); - pos = safecatd(msg, sizeof msg, pos, vi->file_inverse, 2); - } - - else - pos = safecat(msg, sizeof msg, pos, "[linear]"); - - pos = safecat(msg, sizeof msg, pos, "*(alpha)"); - pos = safecatd(msg, sizeof msg, pos, alpha, precision); - } - - /* Now record the *linear* background value if it was used - * (this function is not passed the original, non-linear, - * value but it is contained in the test name.) - */ - if (use_background) - { - pos = safecat(msg, sizeof msg, pos, use_input ? "+" : " "); - pos = safecat(msg, sizeof msg, pos, "(background)"); - pos = safecatd(msg, sizeof msg, pos, background, precision); - pos = safecat(msg, sizeof msg, pos, "*"); - pos = safecatd(msg, sizeof msg, pos, 1-alpha, precision); - } - } - - /* Report the calculated value (input_sample) and the linearized - * libpng value (output) unless this is just a component gamma - * correction. - */ - if (compose || alpha < 0 || pass != 0) - { - pos = safecat(msg, sizeof msg, pos, - pass != 0 ? " =\n\t" : " = "); - pos = safecatd(msg, sizeof msg, pos, input_sample, precision); - pos = safecat(msg, sizeof msg, pos, " (libpng: "); - pos = safecatd(msg, sizeof msg, pos, output, precision); - pos = safecat(msg, sizeof msg, pos, ")"); - - /* Finally report the output gamma encoding, if any. */ - if (output_is_encoded) - { - pos = safecat(msg, sizeof msg, pos, " ^"); - pos = safecatd(msg, sizeof msg, pos, vi->screen_inverse, 2); - pos = safecat(msg, sizeof msg, pos, "(to screen) ="); - } - - else - pos = safecat(msg, sizeof msg, pos, " [screen is linear] ="); - } - - if ((!compose && alpha >= 0) || pass != 0) - { - if (pass != 0) /* logging */ - pos = safecat(msg, sizeof msg, pos, "\n\t[overall:"); - - /* This is the non-composition case, the internal linear - * values are irrelevant (though the log below will reveal - * them.) Output a much shorter warning/error message and report - * the overall gamma correction. - */ - if (vi->gamma_correction > 0) - { - pos = safecat(msg, sizeof msg, pos, " ^"); - pos = safecatd(msg, sizeof msg, pos, vi->gamma_correction, 2); - pos = safecat(msg, sizeof msg, pos, "(gamma correction) ="); - } - - else - pos = safecat(msg, sizeof msg, pos, - " [no gamma correction] ="); - - if (pass != 0) - pos = safecat(msg, sizeof msg, pos, "]"); - } - - /* This is our calculated encoded_sample which should (but does - * not) match od: - */ - pos = safecat(msg, sizeof msg, pos, pass != 0 ? "\n\t" : " "); - pos = safecatd(msg, sizeof msg, pos, is_lo, 1); - pos = safecat(msg, sizeof msg, pos, " < "); - pos = safecatd(msg, sizeof msg, pos, encoded_sample, 1); - pos = safecat(msg, sizeof msg, pos, " (libpng: "); - pos = safecatn(msg, sizeof msg, pos, od); - pos = safecat(msg, sizeof msg, pos, ")"); - pos = safecat(msg, sizeof msg, pos, "/"); - pos = safecatn(msg, sizeof msg, pos, outmax); - pos = safecat(msg, sizeof msg, pos, " < "); - pos = safecatd(msg, sizeof msg, pos, is_hi, 1); - - if (pass == 0) /* The error condition */ - { -# ifdef PNG_WARNINGS_SUPPORTED - png_warning(vi->pp, msg); -# else - store_warning(vi->pp, msg); -# endif - } - - else /* logging this value */ - store_verbose(&vi->dp->pm->this, vi->pp, pass, msg); - } - } - } - - return i; -} - -static void -gamma_image_validate(gamma_display *dp, png_const_structp pp, - png_infop pi) -{ - /* Get some constants derived from the input and output file formats: */ - PNG_CONST png_store* PNG_CONST ps = dp->this.ps; - PNG_CONST png_byte in_ct = dp->this.colour_type; - PNG_CONST png_byte in_bd = dp->this.bit_depth; - PNG_CONST png_uint_32 w = dp->this.w; - PNG_CONST png_uint_32 h = dp->this.h; - PNG_CONST size_t cbRow = dp->this.cbRow; - PNG_CONST png_byte out_ct = png_get_color_type(pp, pi); - PNG_CONST png_byte out_bd = png_get_bit_depth(pp, pi); - - /* There are three sources of error, firstly the quantization in the - * file encoding, determined by sbit and/or the file depth, secondly - * the output (screen) gamma and thirdly the output file encoding. - * - * Since this API receives the screen and file gamma in double - * precision it is possible to calculate an exact answer given an input - * pixel value. Therefore we assume that the *input* value is exact - - * sample/maxsample - calculate the corresponding gamma corrected - * output to the limits of double precision arithmetic and compare with - * what libpng returns. - * - * Since the library must quantize the output to 8 or 16 bits there is - * a fundamental limit on the accuracy of the output of +/-.5 - this - * quantization limit is included in addition to the other limits - * specified by the paramaters to the API. (Effectively, add .5 - * everywhere.) - * - * The behavior of the 'sbit' paramter is defined by section 12.5 - * (sample depth scaling) of the PNG spec. That section forces the - * decoder to assume that the PNG values have been scaled if sBIT is - * present: - * - * png-sample = floor( input-sample * (max-out/max-in) + .5); - * - * This means that only a subset of the possible PNG values should - * appear in the input. However, the spec allows the encoder to use a - * variety of approximations to the above and doesn't require any - * restriction of the values produced. - * - * Nevertheless the spec requires that the upper 'sBIT' bits of the - * value stored in a PNG file be the original sample bits. - * Consequently the code below simply scales the top sbit bits by - * (1<<sbit)-1 to obtain an original sample value. - * - * Because there is limited precision in the input it is arguable that - * an acceptable result is any valid result from input-.5 to input+.5. - * The basic tests below do not do this, however if 'use_input_precision' - * is set a subsequent test is performed above. - */ - PNG_CONST unsigned int samples_per_pixel = (out_ct & 2U) ? 3U : 1U; - int processing; - png_uint_32 y; - PNG_CONST store_palette_entry *in_palette = dp->this.palette; - PNG_CONST int in_is_transparent = dp->this.is_transparent; - int out_npalette = -1; - int out_is_transparent = 0; /* Just refers to the palette case */ - store_palette out_palette; - validate_info vi; - - /* Check for row overwrite errors */ - store_image_check(dp->this.ps, pp, 0); - - /* Supply the input and output sample depths here - 8 for an indexed image, - * otherwise the bit depth. - */ - init_validate_info(&vi, dp, pp, in_ct==3?8:in_bd, out_ct==3?8:out_bd); - - processing = (vi.gamma_correction > 0 && !dp->threshold_test) - || in_bd != out_bd || in_ct != out_ct || vi.do_background; - - /* TODO: FIX THIS: MAJOR BUG! If the transformations all happen inside - * the palette there is no way of finding out, because libpng fails to - * update the palette on png_read_update_info. Indeed, libpng doesn't - * even do the required work until much later, when it doesn't have any - * info pointer. Oops. For the moment 'processing' is turned off if - * out_ct is palette. - */ - if (in_ct == 3 && out_ct == 3) - processing = 0; - - if (processing && out_ct == 3) - out_is_transparent = read_palette(out_palette, &out_npalette, pp, pi); - - for (y=0; y<h; ++y) - { - png_const_bytep pRow = store_image_row(ps, pp, 0, y); - png_byte std[STANDARD_ROWMAX]; - - transform_row(pp, std, in_ct, in_bd, y); - - if (processing) - { - unsigned int x; - - for (x=0; x<w; ++x) - { - double alpha = 1; /* serves as a flag value */ - - /* Record the palette index for index images. */ - PNG_CONST unsigned int in_index = - in_ct == 3 ? sample(std, 3, in_bd, x, 0, 0, 0) : 256; - PNG_CONST unsigned int out_index = - out_ct == 3 ? sample(std, 3, out_bd, x, 0, 0, 0) : 256; - - /* Handle input alpha - png_set_background will cause the output - * alpha to disappear so there is nothing to check. - */ - if ((in_ct & PNG_COLOR_MASK_ALPHA) != 0 || (in_ct == 3 && - in_is_transparent)) - { - PNG_CONST unsigned int input_alpha = in_ct == 3 ? - dp->this.palette[in_index].alpha : - sample(std, in_ct, in_bd, x, samples_per_pixel, 0, 0); - - unsigned int output_alpha = 65536 /* as a flag value */; - - if (out_ct == 3) - { - if (out_is_transparent) - output_alpha = out_palette[out_index].alpha; - } - - else if ((out_ct & PNG_COLOR_MASK_ALPHA) != 0) - output_alpha = sample(pRow, out_ct, out_bd, x, - samples_per_pixel, 0, 0); - - if (output_alpha != 65536) - alpha = gamma_component_validate("alpha", &vi, input_alpha, - output_alpha, -1/*alpha*/, 0/*background*/); - - else /* no alpha in output */ - { - /* This is a copy of the calculation of 'i' above in order to - * have the alpha value to use in the background calculation. - */ - alpha = input_alpha >> vi.isbit_shift; - alpha /= vi.sbit_max; - } - } - - /* Handle grayscale or RGB components. */ - if ((in_ct & PNG_COLOR_MASK_COLOR) == 0) /* grayscale */ - (void)gamma_component_validate("gray", &vi, - sample(std, in_ct, in_bd, x, 0, 0, 0), - sample(pRow, out_ct, out_bd, x, 0, 0, 0), - alpha/*component*/, vi.background_red); - else /* RGB or palette */ - { - (void)gamma_component_validate("red", &vi, - in_ct == 3 ? in_palette[in_index].red : - sample(std, in_ct, in_bd, x, 0, 0, 0), - out_ct == 3 ? out_palette[out_index].red : - sample(pRow, out_ct, out_bd, x, 0, 0, 0), - alpha/*component*/, vi.background_red); - - (void)gamma_component_validate("green", &vi, - in_ct == 3 ? in_palette[in_index].green : - sample(std, in_ct, in_bd, x, 1, 0, 0), - out_ct == 3 ? out_palette[out_index].green : - sample(pRow, out_ct, out_bd, x, 1, 0, 0), - alpha/*component*/, vi.background_green); - - (void)gamma_component_validate("blue", &vi, - in_ct == 3 ? in_palette[in_index].blue : - sample(std, in_ct, in_bd, x, 2, 0, 0), - out_ct == 3 ? out_palette[out_index].blue : - sample(pRow, out_ct, out_bd, x, 2, 0, 0), - alpha/*component*/, vi.background_blue); - } - } - } - - else if (memcmp(std, pRow, cbRow) != 0) - { - char msg[64]; - - /* No transform is expected on the threshold tests. */ - sprintf(msg, "gamma: below threshold row %lu changed", - (unsigned long)y); - - png_error(pp, msg); - } - } /* row (y) loop */ - - dp->this.ps->validated = 1; -} - -static void PNGCBAPI -gamma_end(png_structp ppIn, png_infop pi) -{ - png_const_structp pp = ppIn; - gamma_display *dp = voidcast(gamma_display*, png_get_progressive_ptr(pp)); - - if (!dp->this.speed) - gamma_image_validate(dp, pp, pi); - else - dp->this.ps->validated = 1; -} - -/* A single test run checking a gamma transformation. - * - * maxabs: maximum absolute error as a fraction - * maxout: maximum output error in the output units - * maxpc: maximum percentage error (as a percentage) - */ -static void -gamma_test(png_modifier *pmIn, PNG_CONST png_byte colour_typeIn, - PNG_CONST png_byte bit_depthIn, PNG_CONST int palette_numberIn, - PNG_CONST int interlace_typeIn, - PNG_CONST double file_gammaIn, PNG_CONST double screen_gammaIn, - PNG_CONST png_byte sbitIn, PNG_CONST int threshold_testIn, - PNG_CONST char *name, - PNG_CONST int use_input_precisionIn, PNG_CONST int scale16In, - PNG_CONST int expand16In, PNG_CONST int do_backgroundIn, - PNG_CONST png_color_16 *bkgd_colorIn, double bkgd_gammaIn) -{ - gamma_display d; - context(&pmIn->this, fault); - - gamma_display_init(&d, pmIn, FILEID(colour_typeIn, bit_depthIn, - palette_numberIn, interlace_typeIn, 0, 0, 0), - file_gammaIn, screen_gammaIn, sbitIn, - threshold_testIn, use_input_precisionIn, scale16In, - expand16In, do_backgroundIn, bkgd_colorIn, bkgd_gammaIn); - - Try - { - png_structp pp; - png_infop pi; - gama_modification gama_mod; - srgb_modification srgb_mod; - sbit_modification sbit_mod; - - /* For the moment don't use the png_modifier support here. */ - d.pm->encoding_counter = 0; - modifier_set_encoding(d.pm); /* Just resets everything */ - d.pm->current_gamma = d.file_gamma; - - /* Make an appropriate modifier to set the PNG file gamma to the - * given gamma value and the sBIT chunk to the given precision. - */ - d.pm->modifications = NULL; - gama_modification_init(&gama_mod, d.pm, d.file_gamma); - srgb_modification_init(&srgb_mod, d.pm, 127 /*delete*/); - if (d.sbit > 0) - sbit_modification_init(&sbit_mod, d.pm, d.sbit); - - modification_reset(d.pm->modifications); - - /* Get a png_struct for writing the image. */ - pp = set_modifier_for_read(d.pm, &pi, d.this.id, name); - standard_palette_init(&d.this); - - /* Introduce the correct read function. */ - if (d.pm->this.progressive) - { - /* Share the row function with the standard implementation. */ - png_set_progressive_read_fn(pp, &d, gamma_info, progressive_row, - gamma_end); - - /* Now feed data into the reader until we reach the end: */ - modifier_progressive_read(d.pm, pp, pi); - } - else - { - /* modifier_read expects a png_modifier* */ - png_set_read_fn(pp, d.pm, modifier_read); - - /* Check the header values: */ - png_read_info(pp, pi); - - /* Process the 'info' requirements. Only one image is generated */ - gamma_info_imp(&d, pp, pi); - - sequential_row(&d.this, pp, pi, -1, 0); - - if (!d.this.speed) - gamma_image_validate(&d, pp, pi); - else - d.this.ps->validated = 1; - } - - modifier_reset(d.pm); - - if (d.pm->log && !d.threshold_test && !d.this.speed) - fprintf(stderr, "%d bit %s %s: max error %f (%.2g, %2g%%)\n", - d.this.bit_depth, colour_types[d.this.colour_type], name, - d.maxerrout, d.maxerrabs, 100*d.maxerrpc); - - /* Log the summary values too. */ - if (d.this.colour_type == 0 || d.this.colour_type == 4) - { - switch (d.this.bit_depth) - { - case 1: - break; - - case 2: - if (d.maxerrout > d.pm->error_gray_2) - d.pm->error_gray_2 = d.maxerrout; - - break; - - case 4: - if (d.maxerrout > d.pm->error_gray_4) - d.pm->error_gray_4 = d.maxerrout; - - break; - - case 8: - if (d.maxerrout > d.pm->error_gray_8) - d.pm->error_gray_8 = d.maxerrout; - - break; - - case 16: - if (d.maxerrout > d.pm->error_gray_16) - d.pm->error_gray_16 = d.maxerrout; - - break; - - default: - png_error(pp, "bad bit depth (internal: 1)"); - } - } - - else if (d.this.colour_type == 2 || d.this.colour_type == 6) - { - switch (d.this.bit_depth) - { - case 8: - - if (d.maxerrout > d.pm->error_color_8) - d.pm->error_color_8 = d.maxerrout; - - break; - - case 16: - - if (d.maxerrout > d.pm->error_color_16) - d.pm->error_color_16 = d.maxerrout; - - break; - - default: - png_error(pp, "bad bit depth (internal: 2)"); - } - } - - else if (d.this.colour_type == 3) - { - if (d.maxerrout > d.pm->error_indexed) - d.pm->error_indexed = d.maxerrout; - } - } - - Catch(fault) - modifier_reset(voidcast(png_modifier*,(void*)fault)); -} - -static void gamma_threshold_test(png_modifier *pm, png_byte colour_type, - png_byte bit_depth, int interlace_type, double file_gamma, - double screen_gamma) -{ - size_t pos = 0; - char name[64]; - pos = safecat(name, sizeof name, pos, "threshold "); - pos = safecatd(name, sizeof name, pos, file_gamma, 3); - pos = safecat(name, sizeof name, pos, "/"); - pos = safecatd(name, sizeof name, pos, screen_gamma, 3); - - (void)gamma_test(pm, colour_type, bit_depth, 0/*palette*/, interlace_type, - file_gamma, screen_gamma, 0/*sBIT*/, 1/*threshold test*/, name, - 0 /*no input precision*/, - 0 /*no scale16*/, 0 /*no expand16*/, 0 /*no background*/, 0 /*hence*/, - 0 /*no background gamma*/); -} - -static void -perform_gamma_threshold_tests(png_modifier *pm) -{ - png_byte colour_type = 0; - png_byte bit_depth = 0; - unsigned int palette_number = 0; - - /* Don't test more than one instance of each palette - it's pointless, in - * fact this test is somewhat excessive since libpng doesn't make this - * decision based on colour type or bit depth! - */ - while (next_format(&colour_type, &bit_depth, &palette_number, 1/*gamma*/)) - if (palette_number == 0) - { - double test_gamma = 1.0; - while (test_gamma >= .4) - { - /* There's little point testing the interlacing vs non-interlacing, - * but this can be set from the command line. - */ - gamma_threshold_test(pm, colour_type, bit_depth, pm->interlace_type, - test_gamma, 1/test_gamma); - test_gamma *= .95; - } - - /* And a special test for sRGB */ - gamma_threshold_test(pm, colour_type, bit_depth, pm->interlace_type, - .45455, 2.2); - - if (fail(pm)) - return; - } -} - -static void gamma_transform_test(png_modifier *pm, - PNG_CONST png_byte colour_type, PNG_CONST png_byte bit_depth, - PNG_CONST int palette_number, - PNG_CONST int interlace_type, PNG_CONST double file_gamma, - PNG_CONST double screen_gamma, PNG_CONST png_byte sbit, - PNG_CONST int use_input_precision, PNG_CONST int scale16) -{ - size_t pos = 0; - char name[64]; - - if (sbit != bit_depth && sbit != 0) - { - pos = safecat(name, sizeof name, pos, "sbit("); - pos = safecatn(name, sizeof name, pos, sbit); - pos = safecat(name, sizeof name, pos, ") "); - } - - else - pos = safecat(name, sizeof name, pos, "gamma "); - - if (scale16) - pos = safecat(name, sizeof name, pos, "16to8 "); - - pos = safecatd(name, sizeof name, pos, file_gamma, 3); - pos = safecat(name, sizeof name, pos, "->"); - pos = safecatd(name, sizeof name, pos, screen_gamma, 3); - - gamma_test(pm, colour_type, bit_depth, palette_number, interlace_type, - file_gamma, screen_gamma, sbit, 0, name, use_input_precision, - scale16, pm->test_gamma_expand16, 0 , 0, 0); -} - -static void perform_gamma_transform_tests(png_modifier *pm) -{ - png_byte colour_type = 0; - png_byte bit_depth = 0; - unsigned int palette_number = 0; - - while (next_format(&colour_type, &bit_depth, &palette_number, 1/*gamma*/)) - { - unsigned int i, j; - - for (i=0; i<pm->ngamma_tests; ++i) for (j=0; j<pm->ngamma_tests; ++j) - if (i != j) - { - gamma_transform_test(pm, colour_type, bit_depth, palette_number, - pm->interlace_type, 1/pm->gammas[i], pm->gammas[j], 0/*sBIT*/, - pm->use_input_precision, 0 /*do not scale16*/); - - if (fail(pm)) - return; - } - } -} - -static void perform_gamma_sbit_tests(png_modifier *pm) -{ - png_byte sbit; - - /* The only interesting cases are colour and grayscale, alpha is ignored here - * for overall speed. Only bit depths where sbit is less than the bit depth - * are tested. - */ - for (sbit=pm->sbitlow; sbit<(1<<READ_BDHI); ++sbit) - { - png_byte colour_type = 0, bit_depth = 0; - unsigned int npalette = 0; - - while (next_format(&colour_type, &bit_depth, &npalette, 1/*gamma*/)) - if ((colour_type & PNG_COLOR_MASK_ALPHA) == 0 && - ((colour_type == 3 && sbit < 8) || - (colour_type != 3 && sbit < bit_depth))) - { - unsigned int i; - - for (i=0; i<pm->ngamma_tests; ++i) - { - unsigned int j; - - for (j=0; j<pm->ngamma_tests; ++j) if (i != j) - { - gamma_transform_test(pm, colour_type, bit_depth, npalette, - pm->interlace_type, 1/pm->gammas[i], pm->gammas[j], - sbit, pm->use_input_precision_sbit, 0 /*scale16*/); - - if (fail(pm)) - return; - } - } - } - } -} - -/* Note that this requires a 16 bit source image but produces 8 bit output, so - * we only need the 16bit write support, but the 16 bit images are only - * generated if DO_16BIT is defined. - */ -#ifdef DO_16BIT -static void perform_gamma_scale16_tests(png_modifier *pm) -{ -# ifndef PNG_MAX_GAMMA_8 -# define PNG_MAX_GAMMA_8 11 -# endif -# define SBIT_16_TO_8 PNG_MAX_GAMMA_8 - /* Include the alpha cases here. Note that sbit matches the internal value - * used by the library - otherwise we will get spurious errors from the - * internal sbit style approximation. - * - * The threshold test is here because otherwise the 16 to 8 conversion will - * proceed *without* gamma correction, and the tests above will fail (but not - * by much) - this could be fixed, it only appears with the -g option. - */ - unsigned int i, j; - for (i=0; i<pm->ngamma_tests; ++i) - { - for (j=0; j<pm->ngamma_tests; ++j) - { - if (i != j && - fabs(pm->gammas[j]/pm->gammas[i]-1) >= PNG_GAMMA_THRESHOLD) - { - gamma_transform_test(pm, 0, 16, 0, pm->interlace_type, - 1/pm->gammas[i], pm->gammas[j], SBIT_16_TO_8, - pm->use_input_precision_16to8, 1 /*scale16*/); - - if (fail(pm)) - return; - - gamma_transform_test(pm, 2, 16, 0, pm->interlace_type, - 1/pm->gammas[i], pm->gammas[j], SBIT_16_TO_8, - pm->use_input_precision_16to8, 1 /*scale16*/); - - if (fail(pm)) - return; - - gamma_transform_test(pm, 4, 16, 0, pm->interlace_type, - 1/pm->gammas[i], pm->gammas[j], SBIT_16_TO_8, - pm->use_input_precision_16to8, 1 /*scale16*/); - - if (fail(pm)) - return; - - gamma_transform_test(pm, 6, 16, 0, pm->interlace_type, - 1/pm->gammas[i], pm->gammas[j], SBIT_16_TO_8, - pm->use_input_precision_16to8, 1 /*scale16*/); - - if (fail(pm)) - return; - } - } - } -} -#endif /* 16 to 8 bit conversion */ - -#if defined(PNG_READ_BACKGROUND_SUPPORTED) ||\ - defined(PNG_READ_ALPHA_MODE_SUPPORTED) -static void gamma_composition_test(png_modifier *pm, - PNG_CONST png_byte colour_type, PNG_CONST png_byte bit_depth, - PNG_CONST int palette_number, - PNG_CONST int interlace_type, PNG_CONST double file_gamma, - PNG_CONST double screen_gamma, - PNG_CONST int use_input_precision, PNG_CONST int do_background, - PNG_CONST int expand_16) -{ - size_t pos = 0; - png_const_charp base; - double bg; - char name[128]; - png_color_16 background; - - /* Make up a name and get an appropriate background gamma value. */ - switch (do_background) - { - default: - base = ""; - bg = 4; /* should not be used */ - break; - case PNG_BACKGROUND_GAMMA_SCREEN: - base = " bckg(Screen):"; - bg = 1/screen_gamma; - break; - case PNG_BACKGROUND_GAMMA_FILE: - base = " bckg(File):"; - bg = file_gamma; - break; - case PNG_BACKGROUND_GAMMA_UNIQUE: - base = " bckg(Unique):"; - /* This tests the handling of a unique value, the math is such that the - * value tends to be <1, but is neither screen nor file (even if they - * match!) - */ - bg = (file_gamma + screen_gamma) / 3; - break; -#ifdef PNG_READ_ALPHA_MODE_SUPPORTED - case ALPHA_MODE_OFFSET + PNG_ALPHA_PNG: - base = " alpha(PNG)"; - bg = 4; /* should not be used */ - break; - case ALPHA_MODE_OFFSET + PNG_ALPHA_STANDARD: - base = " alpha(Porter-Duff)"; - bg = 4; /* should not be used */ - break; - case ALPHA_MODE_OFFSET + PNG_ALPHA_OPTIMIZED: - base = " alpha(Optimized)"; - bg = 4; /* should not be used */ - break; - case ALPHA_MODE_OFFSET + PNG_ALPHA_BROKEN: - base = " alpha(Broken)"; - bg = 4; /* should not be used */ - break; -#endif - } - - /* Use random background values - the background is always presented in the - * output space (8 or 16 bit components). - */ - if (expand_16 || bit_depth == 16) - { - png_uint_32 r = random_32(); - - background.red = (png_uint_16)r; - background.green = (png_uint_16)(r >> 16); - r = random_32(); - background.blue = (png_uint_16)r; - background.gray = (png_uint_16)(r >> 16); - - /* In earlier libpng versions, those where DIGITIZE is set, any background - * gamma correction in the expand16 case was done using 8-bit gamma - * correction tables, resulting in larger errors. To cope with those - * cases use a 16-bit background value which will handle this gamma - * correction. - */ -# if DIGITIZE - if (expand_16 && (do_background == PNG_BACKGROUND_GAMMA_UNIQUE || - do_background == PNG_BACKGROUND_GAMMA_FILE) && - fabs(bg*screen_gamma-1) > PNG_GAMMA_THRESHOLD) - { - /* The background values will be looked up in an 8-bit table to do - * the gamma correction, so only select values which are an exact - * match for the 8-bit table entries: - */ - background.red = (png_uint_16)((background.red >> 8) * 257); - background.green = (png_uint_16)((background.green >> 8) * 257); - background.blue = (png_uint_16)((background.blue >> 8) * 257); - background.gray = (png_uint_16)((background.gray >> 8) * 257); - } -# endif - } - - else /* 8 bit colors */ - { - png_uint_32 r = random_32(); - - background.red = (png_byte)r; - background.green = (png_byte)(r >> 8); - background.blue = (png_byte)(r >> 16); - background.gray = (png_byte)(r >> 24); - } - - background.index = 193; /* rgb(193,193,193) to detect errors */ - if (!(colour_type & PNG_COLOR_MASK_COLOR)) - { - /* Grayscale input, we do not convert to RGB (TBD), so we must set the - * background to gray - else libpng seems to fail. - */ - background.red = background.green = background.blue = background.gray; - } - - pos = safecat(name, sizeof name, pos, "gamma "); - pos = safecatd(name, sizeof name, pos, file_gamma, 3); - pos = safecat(name, sizeof name, pos, "->"); - pos = safecatd(name, sizeof name, pos, screen_gamma, 3); - - pos = safecat(name, sizeof name, pos, base); - if (do_background < ALPHA_MODE_OFFSET) - { - /* Include the background color and gamma in the name: */ - pos = safecat(name, sizeof name, pos, "("); - /* This assumes no expand gray->rgb - the current code won't handle that! - */ - if (colour_type & PNG_COLOR_MASK_COLOR) - { - pos = safecatn(name, sizeof name, pos, background.red); - pos = safecat(name, sizeof name, pos, ","); - pos = safecatn(name, sizeof name, pos, background.green); - pos = safecat(name, sizeof name, pos, ","); - pos = safecatn(name, sizeof name, pos, background.blue); - } - else - pos = safecatn(name, sizeof name, pos, background.gray); - pos = safecat(name, sizeof name, pos, ")^"); - pos = safecatd(name, sizeof name, pos, bg, 3); - } - - gamma_test(pm, colour_type, bit_depth, palette_number, interlace_type, - file_gamma, screen_gamma, 0/*sBIT*/, 0, name, use_input_precision, - 0/*strip 16*/, expand_16, do_background, &background, bg); -} - - -static void -perform_gamma_composition_tests(png_modifier *pm, int do_background, - int expand_16) -{ - png_byte colour_type = 0; - png_byte bit_depth = 0; - unsigned int palette_number = 0; - - /* Skip the non-alpha cases - there is no setting of a transparency colour at - * present. - */ - while (next_format(&colour_type, &bit_depth, &palette_number, 1/*gamma*/)) - if ((colour_type & PNG_COLOR_MASK_ALPHA) != 0) - { - unsigned int i, j; - - /* Don't skip the i==j case here - it's relevant. */ - for (i=0; i<pm->ngamma_tests; ++i) for (j=0; j<pm->ngamma_tests; ++j) - { - gamma_composition_test(pm, colour_type, bit_depth, palette_number, - pm->interlace_type, 1/pm->gammas[i], pm->gammas[j], - pm->use_input_precision, do_background, expand_16); - - if (fail(pm)) - return; - } - } -} -#endif /* READ_BACKGROUND || READ_ALPHA_MODE */ - -static void -init_gamma_errors(png_modifier *pm) -{ - /* Use -1 to catch tests that were not actually run */ - pm->error_gray_2 = pm->error_gray_4 = pm->error_gray_8 = -1.; - pm->error_color_8 = -1.; - pm->error_indexed = -1.; - pm->error_gray_16 = pm->error_color_16 = -1.; -} - -static void -print_one(const char *leader, double err) -{ - if (err != -1.) - printf(" %s %.5f\n", leader, err); -} - -static void -summarize_gamma_errors(png_modifier *pm, png_const_charp who, int low_bit_depth, - int indexed) -{ - fflush(stderr); - - if (who) - printf("\nGamma correction with %s:\n", who); - - else - printf("\nBasic gamma correction:\n"); - - if (low_bit_depth) - { - print_one(" 2 bit gray: ", pm->error_gray_2); - print_one(" 4 bit gray: ", pm->error_gray_4); - print_one(" 8 bit gray: ", pm->error_gray_8); - print_one(" 8 bit color:", pm->error_color_8); - if (indexed) - print_one(" indexed: ", pm->error_indexed); - } - - print_one("16 bit gray: ", pm->error_gray_16); - print_one("16 bit color:", pm->error_color_16); - - fflush(stdout); -} - -static void -perform_gamma_test(png_modifier *pm, int summary) -{ - /*TODO: remove this*/ - /* Save certain values for the temporary overrides below. */ - unsigned int calculations_use_input_precision = - pm->calculations_use_input_precision; -# ifdef PNG_READ_BACKGROUND_SUPPORTED - double maxout8 = pm->maxout8; -# endif - - /* First some arbitrary no-transform tests: */ - if (!pm->this.speed && pm->test_gamma_threshold) - { - perform_gamma_threshold_tests(pm); - - if (fail(pm)) - return; - } - - /* Now some real transforms. */ - if (pm->test_gamma_transform) - { - if (summary) - { - fflush(stderr); - printf("Gamma correction error summary\n\n"); - printf("The printed value is the maximum error in the pixel values\n"); - printf("calculated by the libpng gamma correction code. The error\n"); - printf("is calculated as the difference between the output pixel\n"); - printf("value (always an integer) and the ideal value from the\n"); - printf("libpng specification (typically not an integer).\n\n"); - - printf("Expect this value to be less than .5 for 8 bit formats,\n"); - printf("less than 1 for formats with fewer than 8 bits and a small\n"); - printf("number (typically less than 5) for the 16 bit formats.\n"); - printf("For performance reasons the value for 16 bit formats\n"); - printf("increases when the image file includes an sBIT chunk.\n"); - fflush(stdout); - } - - init_gamma_errors(pm); - /*TODO: remove this. Necessary because the current libpng - * implementation works in 8 bits: - */ - if (pm->test_gamma_expand16) - pm->calculations_use_input_precision = 1; - perform_gamma_transform_tests(pm); - if (!calculations_use_input_precision) - pm->calculations_use_input_precision = 0; - - if (summary) - summarize_gamma_errors(pm, 0/*who*/, 1/*low bit depth*/, 1/*indexed*/); - - if (fail(pm)) - return; - } - - /* The sbit tests produce much larger errors: */ - if (pm->test_gamma_sbit) - { - init_gamma_errors(pm); - perform_gamma_sbit_tests(pm); - - if (summary) - summarize_gamma_errors(pm, "sBIT", pm->sbitlow < 8U, 1/*indexed*/); - - if (fail(pm)) - return; - } - -#ifdef DO_16BIT /* Should be READ_16BIT_SUPPORTED */ - if (pm->test_gamma_scale16) - { - /* The 16 to 8 bit strip operations: */ - init_gamma_errors(pm); - perform_gamma_scale16_tests(pm); - - if (summary) - { - fflush(stderr); - printf("\nGamma correction with 16 to 8 bit reduction:\n"); - printf(" 16 bit gray: %.5f\n", pm->error_gray_16); - printf(" 16 bit color: %.5f\n", pm->error_color_16); - fflush(stdout); - } - - if (fail(pm)) - return; - } -#endif - -#ifdef PNG_READ_BACKGROUND_SUPPORTED - if (pm->test_gamma_background) - { - init_gamma_errors(pm); - - /*TODO: remove this. Necessary because the current libpng - * implementation works in 8 bits: - */ - if (pm->test_gamma_expand16) - { - pm->calculations_use_input_precision = 1; - pm->maxout8 = .499; /* because the 16 bit background is smashed */ - } - perform_gamma_composition_tests(pm, PNG_BACKGROUND_GAMMA_UNIQUE, - pm->test_gamma_expand16); - if (!calculations_use_input_precision) - pm->calculations_use_input_precision = 0; - pm->maxout8 = maxout8; - - if (summary) - summarize_gamma_errors(pm, "background", 1, 0/*indexed*/); - - if (fail(pm)) - return; - } -#endif - -#ifdef PNG_READ_ALPHA_MODE_SUPPORTED - if (pm->test_gamma_alpha_mode) - { - int do_background; - - init_gamma_errors(pm); - - /*TODO: remove this. Necessary because the current libpng - * implementation works in 8 bits: - */ - if (pm->test_gamma_expand16) - pm->calculations_use_input_precision = 1; - for (do_background = ALPHA_MODE_OFFSET + PNG_ALPHA_STANDARD; - do_background <= ALPHA_MODE_OFFSET + PNG_ALPHA_BROKEN && !fail(pm); - ++do_background) - perform_gamma_composition_tests(pm, do_background, - pm->test_gamma_expand16); - if (!calculations_use_input_precision) - pm->calculations_use_input_precision = 0; - - if (summary) - summarize_gamma_errors(pm, "alpha mode", 1, 0/*indexed*/); - - if (fail(pm)) - return; - } -#endif -} -#endif /* PNG_READ_GAMMA_SUPPORTED */ -#endif /* PNG_READ_SUPPORTED */ - -/* INTERLACE MACRO VALIDATION */ -/* This is copied verbatim from the specification, it is simply the pass - * number in which each pixel in each 8x8 tile appears. The array must - * be indexed adam7[y][x] and notice that the pass numbers are based at - * 1, not 0 - the base libpng uses. - */ -static PNG_CONST -png_byte adam7[8][8] = -{ - { 1,6,4,6,2,6,4,6 }, - { 7,7,7,7,7,7,7,7 }, - { 5,6,5,6,5,6,5,6 }, - { 7,7,7,7,7,7,7,7 }, - { 3,6,4,6,3,6,4,6 }, - { 7,7,7,7,7,7,7,7 }, - { 5,6,5,6,5,6,5,6 }, - { 7,7,7,7,7,7,7,7 } -}; - -/* This routine validates all the interlace support macros in png.h for - * a variety of valid PNG widths and heights. It uses a number of similarly - * named internal routines that feed off the above array. - */ -static png_uint_32 -png_pass_start_row(int pass) -{ - int x, y; - ++pass; - for (y=0; y<8; ++y) for (x=0; x<8; ++x) if (adam7[y][x] == pass) - return y; - return 0xf; -} - -static png_uint_32 -png_pass_start_col(int pass) -{ - int x, y; - ++pass; - for (x=0; x<8; ++x) for (y=0; y<8; ++y) if (adam7[y][x] == pass) - return x; - return 0xf; -} - -static int -png_pass_row_shift(int pass) -{ - int x, y, base=(-1), inc=8; - ++pass; - for (y=0; y<8; ++y) for (x=0; x<8; ++x) if (adam7[y][x] == pass) - { - if (base == (-1)) - base = y; - else if (base == y) - {} - else if (inc == y-base) - base=y; - else if (inc == 8) - inc = y-base, base=y; - else if (inc != y-base) - return 0xff; /* error - more than one 'inc' value! */ - } - - if (base == (-1)) return 0xfe; /* error - no row in pass! */ - - /* The shift is always 1, 2 or 3 - no pass has all the rows! */ - switch (inc) - { -case 2: return 1; -case 4: return 2; -case 8: return 3; -default: break; - } - - /* error - unrecognized 'inc' */ - return (inc << 8) + 0xfd; -} - -static int -png_pass_col_shift(int pass) -{ - int x, y, base=(-1), inc=8; - ++pass; - for (x=0; x<8; ++x) for (y=0; y<8; ++y) if (adam7[y][x] == pass) - { - if (base == (-1)) - base = x; - else if (base == x) - {} - else if (inc == x-base) - base=x; - else if (inc == 8) - inc = x-base, base=x; - else if (inc != x-base) - return 0xff; /* error - more than one 'inc' value! */ - } - - if (base == (-1)) return 0xfe; /* error - no row in pass! */ - - /* The shift is always 1, 2 or 3 - no pass has all the rows! */ - switch (inc) - { -case 1: return 0; /* pass 7 has all the columns */ -case 2: return 1; -case 4: return 2; -case 8: return 3; -default: break; - } - - /* error - unrecognized 'inc' */ - return (inc << 8) + 0xfd; -} - -static png_uint_32 -png_row_from_pass_row(png_uint_32 yIn, int pass) -{ - /* By examination of the array: */ - switch (pass) - { -case 0: return yIn * 8; -case 1: return yIn * 8; -case 2: return yIn * 8 + 4; -case 3: return yIn * 4; -case 4: return yIn * 4 + 2; -case 5: return yIn * 2; -case 6: return yIn * 2 + 1; -default: break; - } - - return 0xff; /* bad pass number */ -} - -static png_uint_32 -png_col_from_pass_col(png_uint_32 xIn, int pass) -{ - /* By examination of the array: */ - switch (pass) - { -case 0: return xIn * 8; -case 1: return xIn * 8 + 4; -case 2: return xIn * 4; -case 3: return xIn * 4 + 2; -case 4: return xIn * 2; -case 5: return xIn * 2 + 1; -case 6: return xIn; -default: break; - } - - return 0xff; /* bad pass number */ -} - -static int -png_row_in_interlace_pass(png_uint_32 y, int pass) -{ - /* Is row 'y' in pass 'pass'? */ - int x; - y &= 7; - ++pass; - for (x=0; x<8; ++x) if (adam7[y][x] == pass) - return 1; - - return 0; -} - -static int -png_col_in_interlace_pass(png_uint_32 x, int pass) -{ - /* Is column 'x' in pass 'pass'? */ - int y; - x &= 7; - ++pass; - for (y=0; y<8; ++y) if (adam7[y][x] == pass) - return 1; - - return 0; -} - -static png_uint_32 -png_pass_rows(png_uint_32 height, int pass) -{ - png_uint_32 tiles = height>>3; - png_uint_32 rows = 0; - unsigned int x, y; - - height &= 7; - ++pass; - for (y=0; y<8; ++y) for (x=0; x<8; ++x) if (adam7[y][x] == pass) - { - rows += tiles; - if (y < height) ++rows; - break; /* i.e. break the 'x', column, loop. */ - } - - return rows; -} - -static png_uint_32 -png_pass_cols(png_uint_32 width, int pass) -{ - png_uint_32 tiles = width>>3; - png_uint_32 cols = 0; - unsigned int x, y; - - width &= 7; - ++pass; - for (x=0; x<8; ++x) for (y=0; y<8; ++y) if (adam7[y][x] == pass) - { - cols += tiles; - if (x < width) ++cols; - break; /* i.e. break the 'y', row, loop. */ - } - - return cols; -} - -static void -perform_interlace_macro_validation(void) -{ - /* The macros to validate, first those that depend only on pass: - * - * PNG_PASS_START_ROW(pass) - * PNG_PASS_START_COL(pass) - * PNG_PASS_ROW_SHIFT(pass) - * PNG_PASS_COL_SHIFT(pass) - */ - int pass; - - for (pass=0; pass<7; ++pass) - { - png_uint_32 m, f, v; - - m = PNG_PASS_START_ROW(pass); - f = png_pass_start_row(pass); - if (m != f) - { - fprintf(stderr, "PNG_PASS_START_ROW(%d) = %u != %x\n", pass, m, f); - exit(99); - } - - m = PNG_PASS_START_COL(pass); - f = png_pass_start_col(pass); - if (m != f) - { - fprintf(stderr, "PNG_PASS_START_COL(%d) = %u != %x\n", pass, m, f); - exit(99); - } - - m = PNG_PASS_ROW_SHIFT(pass); - f = png_pass_row_shift(pass); - if (m != f) - { - fprintf(stderr, "PNG_PASS_ROW_SHIFT(%d) = %u != %x\n", pass, m, f); - exit(99); - } - - m = PNG_PASS_COL_SHIFT(pass); - f = png_pass_col_shift(pass); - if (m != f) - { - fprintf(stderr, "PNG_PASS_COL_SHIFT(%d) = %u != %x\n", pass, m, f); - exit(99); - } - - /* Macros that depend on the image or sub-image height too: - * - * PNG_PASS_ROWS(height, pass) - * PNG_PASS_COLS(width, pass) - * PNG_ROW_FROM_PASS_ROW(yIn, pass) - * PNG_COL_FROM_PASS_COL(xIn, pass) - * PNG_ROW_IN_INTERLACE_PASS(y, pass) - * PNG_COL_IN_INTERLACE_PASS(x, pass) - */ - for (v=0;;) - { - /* First the base 0 stuff: */ - m = PNG_ROW_FROM_PASS_ROW(v, pass); - f = png_row_from_pass_row(v, pass); - if (m != f) - { - fprintf(stderr, "PNG_ROW_FROM_PASS_ROW(%u, %d) = %u != %x\n", - v, pass, m, f); - exit(99); - } - - m = PNG_COL_FROM_PASS_COL(v, pass); - f = png_col_from_pass_col(v, pass); - if (m != f) - { - fprintf(stderr, "PNG_COL_FROM_PASS_COL(%u, %d) = %u != %x\n", - v, pass, m, f); - exit(99); - } - - m = PNG_ROW_IN_INTERLACE_PASS(v, pass); - f = png_row_in_interlace_pass(v, pass); - if (m != f) - { - fprintf(stderr, "PNG_ROW_IN_INTERLACE_PASS(%u, %d) = %u != %x\n", - v, pass, m, f); - exit(99); - } - - m = PNG_COL_IN_INTERLACE_PASS(v, pass); - f = png_col_in_interlace_pass(v, pass); - if (m != f) - { - fprintf(stderr, "PNG_COL_IN_INTERLACE_PASS(%u, %d) = %u != %x\n", - v, pass, m, f); - exit(99); - } - - /* Then the base 1 stuff: */ - ++v; - m = PNG_PASS_ROWS(v, pass); - f = png_pass_rows(v, pass); - if (m != f) - { - fprintf(stderr, "PNG_PASS_ROWS(%u, %d) = %u != %x\n", - v, pass, m, f); - exit(99); - } - - m = PNG_PASS_COLS(v, pass); - f = png_pass_cols(v, pass); - if (m != f) - { - fprintf(stderr, "PNG_PASS_COLS(%u, %d) = %u != %x\n", - v, pass, m, f); - exit(99); - } - - /* Move to the next v - the stepping algorithm starts skipping - * values above 1024. - */ - if (v > 1024) - { - if (v == PNG_UINT_31_MAX) - break; - - v = (v << 1) ^ v; - if (v >= PNG_UINT_31_MAX) - v = PNG_UINT_31_MAX-1; - } - } - } -} - -/* Test color encodings. These values are back-calculated from the published - * chromaticities. The values are accurate to about 14 decimal places; 15 are - * given. These values are much more accurate than the ones given in the spec, - * which typically don't exceed 4 decimal places. This allows testing of the - * libpng code to its theoretical accuracy of 4 decimal places. (If pngvalid - * used the published errors the 'slack' permitted would have to be +/-.5E-4 or - * more.) - * - * The png_modifier code assumes that encodings[0] is sRGB and treats it - * specially: do not change the first entry in this list! - */ -static PNG_CONST color_encoding test_encodings[] = -{ -/* sRGB: must be first in this list! */ -/*gamma:*/ { 1/2.2, -/*red: */ { 0.412390799265959, 0.212639005871510, 0.019330818715592 }, -/*green:*/ { 0.357584339383878, 0.715168678767756, 0.119194779794626 }, -/*blue: */ { 0.180480788401834, 0.072192315360734, 0.950532152249660} }, -/* Kodak ProPhoto (wide gamut) */ -/*gamma:*/ { 1/1.6 /*approximate: uses 1.8 power law compared to sRGB 2.4*/, -/*red: */ { 0.797760489672303, 0.288071128229293, 0.000000000000000 }, -/*green:*/ { 0.135185837175740, 0.711843217810102, 0.000000000000000 }, -/*blue: */ { 0.031349349581525, 0.000085653960605, 0.825104602510460} }, -/* Adobe RGB (1998) */ -/*gamma:*/ { 1/(2+51./256), -/*red: */ { 0.576669042910131, 0.297344975250536, 0.027031361386412 }, -/*green:*/ { 0.185558237906546, 0.627363566255466, 0.070688852535827 }, -/*blue: */ { 0.188228646234995, 0.075291458493998, 0.991337536837639} }, -/* Adobe Wide Gamut RGB */ -/*gamma:*/ { 1/(2+51./256), -/*red: */ { 0.716500716779386, 0.258728243040113, 0.000000000000000 }, -/*green:*/ { 0.101020574397477, 0.724682314948566, 0.051211818965388 }, -/*blue: */ { 0.146774385252705, 0.016589442011321, 0.773892783545073} }, -}; - -/* signal handler - * - * This attempts to trap signals and escape without crashing. It needs a - * context pointer so that it can throw an exception (call longjmp) to recover - * from the condition; this is handled by making the png_modifier used by 'main' - * into a global variable. - */ -static png_modifier pm; - -static void signal_handler(int signum) -{ - - size_t pos = 0; - char msg[64]; - - pos = safecat(msg, sizeof msg, pos, "caught signal: "); - - switch (signum) - { - case SIGABRT: - pos = safecat(msg, sizeof msg, pos, "abort"); - break; - - case SIGFPE: - pos = safecat(msg, sizeof msg, pos, "floating point exception"); - break; - - case SIGILL: - pos = safecat(msg, sizeof msg, pos, "illegal instruction"); - break; - - case SIGINT: - pos = safecat(msg, sizeof msg, pos, "interrupt"); - break; - - case SIGSEGV: - pos = safecat(msg, sizeof msg, pos, "invalid memory access"); - break; - - case SIGTERM: - pos = safecat(msg, sizeof msg, pos, "termination request"); - break; - - default: - pos = safecat(msg, sizeof msg, pos, "unknown "); - pos = safecatn(msg, sizeof msg, pos, signum); - break; - } - - store_log(&pm.this, NULL/*png_structp*/, msg, 1/*error*/); - - /* And finally throw an exception so we can keep going, unless this is - * SIGTERM in which case stop now. - */ - if (signum != SIGTERM) - { - struct exception_context *the_exception_context = - &pm.this.exception_context; - - Throw &pm.this; - } - - else - exit(1); -} - -/* main program */ -int main(int argc, char **argv) -{ - volatile int summary = 1; /* Print the error summary at the end */ - volatile int memstats = 0; /* Print memory statistics at the end */ - - /* Create the given output file on success: */ - PNG_CONST char *volatile touch = NULL; - - /* This is an array of standard gamma values (believe it or not I've seen - * every one of these mentioned somewhere.) - * - * In the following list the most useful values are first! - */ - static double - gammas[]={2.2, 1.0, 2.2/1.45, 1.8, 1.5, 2.4, 2.5, 2.62, 2.9}; - - /* This records the command and arguments: */ - size_t cp = 0; - char command[1024]; - - anon_context(&pm.this); - - /* Add appropriate signal handlers, just the ANSI specified ones: */ - signal(SIGABRT, signal_handler); - signal(SIGFPE, signal_handler); - signal(SIGILL, signal_handler); - signal(SIGINT, signal_handler); - signal(SIGSEGV, signal_handler); - signal(SIGTERM, signal_handler); - -#ifdef HAVE_FEENABLEEXCEPT - /* Only required to enable FP exceptions on platforms where they start off - * disabled; this is not necessary but if it is not done pngvalid will likely - * end up ignoring FP conditions that other platforms fault. - */ - feenableexcept(FE_DIVBYZERO | FE_INVALID | FE_OVERFLOW); -#endif - - modifier_init(&pm); - - /* Preallocate the image buffer, because we know how big it needs to be, - * note that, for testing purposes, it is deliberately mis-aligned by tag - * bytes either side. All rows have an additional five bytes of padding for - * overwrite checking. - */ - store_ensure_image(&pm.this, NULL, 2, TRANSFORM_ROWMAX, TRANSFORM_HEIGHTMAX); - - /* Don't give argv[0], it's normally some horrible libtool string: */ - cp = safecat(command, sizeof command, cp, "pngvalid"); - - /* Default to error on warning: */ - pm.this.treat_warnings_as_errors = 1; - - /* Default assume_16_bit_calculations appropriately; this tells the checking - * code that 16-bit arithmetic is used for 8-bit samples when it would make a - * difference. - */ - pm.assume_16_bit_calculations = PNG_LIBPNG_VER >= 10700; - - /* Currently 16 bit expansion happens at the end of the pipeline, so the - * calculations are done in the input bit depth not the output. - * - * TODO: fix this - */ - pm.calculations_use_input_precision = 1U; - - /* Store the test gammas */ - pm.gammas = gammas; - pm.ngammas = ARRAY_SIZE(gammas); - pm.ngamma_tests = 0; /* default to off */ - - /* And the test encodings */ - pm.encodings = test_encodings; - pm.nencodings = ARRAY_SIZE(test_encodings); - - pm.sbitlow = 8U; /* because libpng doesn't do sBIT below 8! */ - - /* The following allows results to pass if they correspond to anything in the - * transformed range [input-.5,input+.5]; this is is required because of the - * way libpng treates the 16_TO_8 flag when building the gamma tables in - * releases up to 1.6.0. - * - * TODO: review this - */ - pm.use_input_precision_16to8 = 1U; - pm.use_input_precision_sbit = 1U; /* because libpng now rounds sBIT */ - - /* Some default values (set the behavior for 'make check' here). - * These values simply control the maximum error permitted in the gamma - * transformations. The practial limits for human perception are described - * below (the setting for maxpc16), however for 8 bit encodings it isn't - * possible to meet the accepted capabilities of human vision - i.e. 8 bit - * images can never be good enough, regardless of encoding. - */ - pm.maxout8 = .1; /* Arithmetic error in *encoded* value */ - pm.maxabs8 = .00005; /* 1/20000 */ - pm.maxcalc8 = 1./255; /* +/-1 in 8 bits for compose errors */ - pm.maxpc8 = .499; /* I.e., .499% fractional error */ - pm.maxout16 = .499; /* Error in *encoded* value */ - pm.maxabs16 = .00005;/* 1/20000 */ - pm.maxcalc16 =1./65535;/* +/-1 in 16 bits for compose errors */ - pm.maxcalcG = 1./((1<<PNG_MAX_GAMMA_8)-1); - - /* NOTE: this is a reasonable perceptual limit. We assume that humans can - * perceive light level differences of 1% over a 100:1 range, so we need to - * maintain 1 in 10000 accuracy (in linear light space), which is what the - * following guarantees. It also allows significantly higher errors at - * higher 16 bit values, which is important for performance. The actual - * maximum 16 bit error is about +/-1.9 in the fixed point implementation but - * this is only allowed for values >38149 by the following: - */ - pm.maxpc16 = .005; /* I.e., 1/200% - 1/20000 */ - - /* Now parse the command line options. */ - while (--argc >= 1) - { - int catmore = 0; /* Set if the argument has an argument. */ - - /* Record each argument for posterity: */ - cp = safecat(command, sizeof command, cp, " "); - cp = safecat(command, sizeof command, cp, *++argv); - - if (strcmp(*argv, "-v") == 0) - pm.this.verbose = 1; - - else if (strcmp(*argv, "-l") == 0) - pm.log = 1; - - else if (strcmp(*argv, "-q") == 0) - summary = pm.this.verbose = pm.log = 0; - - else if (strcmp(*argv, "-w") == 0) - pm.this.treat_warnings_as_errors = 0; - - else if (strcmp(*argv, "--speed") == 0) - pm.this.speed = 1, pm.ngamma_tests = pm.ngammas, pm.test_standard = 0, - summary = 0; - - else if (strcmp(*argv, "--memory") == 0) - memstats = 1; - - else if (strcmp(*argv, "--size") == 0) - pm.test_size = 1; - - else if (strcmp(*argv, "--nosize") == 0) - pm.test_size = 0; - - else if (strcmp(*argv, "--standard") == 0) - pm.test_standard = 1; - - else if (strcmp(*argv, "--nostandard") == 0) - pm.test_standard = 0; - - else if (strcmp(*argv, "--transform") == 0) - pm.test_transform = 1; - - else if (strcmp(*argv, "--notransform") == 0) - pm.test_transform = 0; - -#ifdef PNG_READ_TRANSFORMS_SUPPORTED - else if (strncmp(*argv, "--transform-disable=", - sizeof "--transform-disable") == 0) - { - pm.test_transform = 1; - transform_disable(*argv + sizeof "--transform-disable"); - } - - else if (strncmp(*argv, "--transform-enable=", - sizeof "--transform-enable") == 0) - { - pm.test_transform = 1; - transform_enable(*argv + sizeof "--transform-enable"); - } -#endif /* PNG_READ_TRANSFORMS_SUPPORTED */ - - else if (strcmp(*argv, "--gamma") == 0) - { - /* Just do two gamma tests here (2.2 and linear) for speed: */ - pm.ngamma_tests = 2U; - pm.test_gamma_threshold = 1; - pm.test_gamma_transform = 1; - pm.test_gamma_sbit = 1; - pm.test_gamma_scale16 = 1; - pm.test_gamma_background = 1; - pm.test_gamma_alpha_mode = 1; - } - - else if (strcmp(*argv, "--nogamma") == 0) - pm.ngamma_tests = 0; - - else if (strcmp(*argv, "--gamma-threshold") == 0) - pm.ngamma_tests = 2U, pm.test_gamma_threshold = 1; - - else if (strcmp(*argv, "--nogamma-threshold") == 0) - pm.test_gamma_threshold = 0; - - else if (strcmp(*argv, "--gamma-transform") == 0) - pm.ngamma_tests = 2U, pm.test_gamma_transform = 1; - - else if (strcmp(*argv, "--nogamma-transform") == 0) - pm.test_gamma_transform = 0; - - else if (strcmp(*argv, "--gamma-sbit") == 0) - pm.ngamma_tests = 2U, pm.test_gamma_sbit = 1; - - else if (strcmp(*argv, "--nogamma-sbit") == 0) - pm.test_gamma_sbit = 0; - - else if (strcmp(*argv, "--gamma-16-to-8") == 0) - pm.ngamma_tests = 2U, pm.test_gamma_scale16 = 1; - - else if (strcmp(*argv, "--nogamma-16-to-8") == 0) - pm.test_gamma_scale16 = 0; - - else if (strcmp(*argv, "--gamma-background") == 0) - pm.ngamma_tests = 2U, pm.test_gamma_background = 1; - - else if (strcmp(*argv, "--nogamma-background") == 0) - pm.test_gamma_background = 0; - - else if (strcmp(*argv, "--gamma-alpha-mode") == 0) - pm.ngamma_tests = 2U, pm.test_gamma_alpha_mode = 1; - - else if (strcmp(*argv, "--nogamma-alpha-mode") == 0) - pm.test_gamma_alpha_mode = 0; - - else if (strcmp(*argv, "--expand16") == 0) - pm.test_gamma_expand16 = 1; - - else if (strcmp(*argv, "--noexpand16") == 0) - pm.test_gamma_expand16 = 0; - - else if (strcmp(*argv, "--more-gammas") == 0) - pm.ngamma_tests = 3U; - - else if (strcmp(*argv, "--all-gammas") == 0) - pm.ngamma_tests = pm.ngammas; - - else if (strcmp(*argv, "--progressive-read") == 0) - pm.this.progressive = 1; - - else if (strcmp(*argv, "--use-update-info") == 0) - ++pm.use_update_info; /* Can call multiple times */ - - else if (strcmp(*argv, "--interlace") == 0) - { -# ifdef PNG_WRITE_INTERLACING_SUPPORTED - pm.interlace_type = PNG_INTERLACE_ADAM7; -# else - fprintf(stderr, "pngvalid: no write interlace support\n"); - return SKIP; -# endif - } - - else if (strcmp(*argv, "--use-input-precision") == 0) - pm.use_input_precision = 1U; - - else if (strcmp(*argv, "--use-calculation-precision") == 0) - pm.use_input_precision = 0; - - else if (strcmp(*argv, "--calculations-use-input-precision") == 0) - pm.calculations_use_input_precision = 1U; - - else if (strcmp(*argv, "--assume-16-bit-calculations") == 0) - pm.assume_16_bit_calculations = 1U; - - else if (strcmp(*argv, "--calculations-follow-bit-depth") == 0) - pm.calculations_use_input_precision = - pm.assume_16_bit_calculations = 0; - - else if (strcmp(*argv, "--exhaustive") == 0) - pm.test_exhaustive = 1; - - else if (argc > 1 && strcmp(*argv, "--sbitlow") == 0) - --argc, pm.sbitlow = (png_byte)atoi(*++argv), catmore = 1; - - else if (argc > 1 && strcmp(*argv, "--touch") == 0) - --argc, touch = *++argv, catmore = 1; - - else if (argc > 1 && strncmp(*argv, "--max", 5) == 0) - { - --argc; - - if (strcmp(5+*argv, "abs8") == 0) - pm.maxabs8 = atof(*++argv); - - else if (strcmp(5+*argv, "abs16") == 0) - pm.maxabs16 = atof(*++argv); - - else if (strcmp(5+*argv, "calc8") == 0) - pm.maxcalc8 = atof(*++argv); - - else if (strcmp(5+*argv, "calc16") == 0) - pm.maxcalc16 = atof(*++argv); - - else if (strcmp(5+*argv, "out8") == 0) - pm.maxout8 = atof(*++argv); - - else if (strcmp(5+*argv, "out16") == 0) - pm.maxout16 = atof(*++argv); - - else if (strcmp(5+*argv, "pc8") == 0) - pm.maxpc8 = atof(*++argv); - - else if (strcmp(5+*argv, "pc16") == 0) - pm.maxpc16 = atof(*++argv); - - else - { - fprintf(stderr, "pngvalid: %s: unknown 'max' option\n", *argv); - exit(99); - } - - catmore = 1; - } - - else if (strcmp(*argv, "--log8") == 0) - --argc, pm.log8 = atof(*++argv), catmore = 1; - - else if (strcmp(*argv, "--log16") == 0) - --argc, pm.log16 = atof(*++argv), catmore = 1; - -#ifdef PNG_SET_OPTION_SUPPORTED - else if (strncmp(*argv, "--option=", 9) == 0) - { - /* Syntax of the argument is <option>:{on|off} */ - const char *arg = 9+*argv; - unsigned char option=0, setting=0; - -#ifdef PNG_ARM_NEON_API_SUPPORTED - if (strncmp(arg, "arm-neon:", 9) == 0) - option = PNG_ARM_NEON, arg += 9; - - else -#endif -#ifdef PNG_MAXIMUM_INFLATE_WINDOW - if (strncmp(arg, "max-inflate-window:", 19) == 0) - option = PNG_MAXIMUM_INFLATE_WINDOW, arg += 19; - - else -#endif - { - fprintf(stderr, "pngvalid: %s: %s: unknown option\n", *argv, arg); - exit(99); - } - - if (strcmp(arg, "off") == 0) - setting = PNG_OPTION_OFF; - - else if (strcmp(arg, "on") == 0) - setting = PNG_OPTION_ON; - - else - { - fprintf(stderr, - "pngvalid: %s: %s: unknown setting (use 'on' or 'off')\n", - *argv, arg); - exit(99); - } - - pm.this.options[pm.this.noptions].option = option; - pm.this.options[pm.this.noptions++].setting = setting; - } -#endif /* PNG_SET_OPTION_SUPPORTED */ - - else - { - fprintf(stderr, "pngvalid: %s: unknown argument\n", *argv); - exit(99); - } - - if (catmore) /* consumed an extra *argv */ - { - cp = safecat(command, sizeof command, cp, " "); - cp = safecat(command, sizeof command, cp, *argv); - } - } - - /* If pngvalid is run with no arguments default to a reasonable set of the - * tests. - */ - if (pm.test_standard == 0 && pm.test_size == 0 && pm.test_transform == 0 && - pm.ngamma_tests == 0) - { - /* Make this do all the tests done in the test shell scripts with the same - * parameters, where possible. The limitation is that all the progressive - * read and interlace stuff has to be done in separate runs, so only the - * basic 'standard' and 'size' tests are done. - */ - pm.test_standard = 1; - pm.test_size = 1; - pm.test_transform = 1; - pm.ngamma_tests = 2U; - } - - if (pm.ngamma_tests > 0 && - pm.test_gamma_threshold == 0 && pm.test_gamma_transform == 0 && - pm.test_gamma_sbit == 0 && pm.test_gamma_scale16 == 0 && - pm.test_gamma_background == 0 && pm.test_gamma_alpha_mode == 0) - { - pm.test_gamma_threshold = 1; - pm.test_gamma_transform = 1; - pm.test_gamma_sbit = 1; - pm.test_gamma_scale16 = 1; - pm.test_gamma_background = 1; - pm.test_gamma_alpha_mode = 1; - } - - else if (pm.ngamma_tests == 0) - { - /* Nothing to test so turn everything off: */ - pm.test_gamma_threshold = 0; - pm.test_gamma_transform = 0; - pm.test_gamma_sbit = 0; - pm.test_gamma_scale16 = 0; - pm.test_gamma_background = 0; - pm.test_gamma_alpha_mode = 0; - } - - Try - { - /* Make useful base images */ - make_transform_images(&pm.this); - - /* Perform the standard and gamma tests. */ - if (pm.test_standard) - { - perform_interlace_macro_validation(); - perform_formatting_test(&pm.this); -# ifdef PNG_READ_SUPPORTED - perform_standard_test(&pm); -# endif - perform_error_test(&pm); - } - - /* Various oddly sized images: */ - if (pm.test_size) - { - make_size_images(&pm.this); -# ifdef PNG_READ_SUPPORTED - perform_size_test(&pm); -# endif - } - -#ifdef PNG_READ_TRANSFORMS_SUPPORTED - /* Combinatorial transforms: */ - if (pm.test_transform) - perform_transform_test(&pm); -#endif /* PNG_READ_TRANSFORMS_SUPPORTED */ - -#ifdef PNG_READ_GAMMA_SUPPORTED - if (pm.ngamma_tests > 0) - perform_gamma_test(&pm, summary); -#endif - } - - Catch_anonymous - { - fprintf(stderr, "pngvalid: test aborted (probably failed in cleanup)\n"); - if (!pm.this.verbose) - { - if (pm.this.error[0] != 0) - fprintf(stderr, "pngvalid: first error: %s\n", pm.this.error); - - fprintf(stderr, "pngvalid: run with -v to see what happened\n"); - } - exit(1); - } - - if (summary) - { - printf("%s: %s (%s point arithmetic)\n", - (pm.this.nerrors || (pm.this.treat_warnings_as_errors && - pm.this.nwarnings)) ? "FAIL" : "PASS", - command, -#if defined(PNG_FLOATING_ARITHMETIC_SUPPORTED) || PNG_LIBPNG_VER < 10500 - "floating" -#else - "fixed" -#endif - ); - } - - if (memstats) - { - printf("Allocated memory statistics (in bytes):\n" - "\tread %lu maximum single, %lu peak, %lu total\n" - "\twrite %lu maximum single, %lu peak, %lu total\n", - (unsigned long)pm.this.read_memory_pool.max_max, - (unsigned long)pm.this.read_memory_pool.max_limit, - (unsigned long)pm.this.read_memory_pool.max_total, - (unsigned long)pm.this.write_memory_pool.max_max, - (unsigned long)pm.this.write_memory_pool.max_limit, - (unsigned long)pm.this.write_memory_pool.max_total); - } - - /* Do this here to provoke memory corruption errors in memory not directly - * allocated by libpng - not a complete test, but better than nothing. - */ - store_delete(&pm.this); - - /* Error exit if there are any errors, and maybe if there are any - * warnings. - */ - if (pm.this.nerrors || (pm.this.treat_warnings_as_errors && - pm.this.nwarnings)) - { - if (!pm.this.verbose) - fprintf(stderr, "pngvalid: %s\n", pm.this.error); - - fprintf(stderr, "pngvalid: %d errors, %d warnings\n", pm.this.nerrors, - pm.this.nwarnings); - - exit(1); - } - - /* Success case. */ - if (touch != NULL) - { - FILE *fsuccess = fopen(touch, "wt"); - - if (fsuccess != NULL) - { - int error = 0; - fprintf(fsuccess, "PNG validation succeeded\n"); - fflush(fsuccess); - error = ferror(fsuccess); - - if (fclose(fsuccess) || error) - { - fprintf(stderr, "%s: write failed\n", touch); - exit(1); - } - } - - else - { - fprintf(stderr, "%s: open failed\n", touch); - exit(1); - } - } - - /* This is required because some very minimal configurations do not use it: - */ - UNUSED(fail) - return 0; -} -#else /* write or low level APIs not supported */ -int main(void) -{ - fprintf(stderr, - "pngvalid: no low level write support in libpng, all tests skipped\n"); - /* So the test is skipped: */ - return SKIP; -} -#endif |