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diff --git a/Build/source/libs/libpng/libpng-1.6.2/contrib/libtests/pngvalid.c b/Build/source/libs/libpng/libpng-1.6.2/contrib/libtests/pngvalid.c
deleted file mode 100644
index fbd6778cf36..00000000000
--- a/Build/source/libs/libpng/libpng-1.6.2/contrib/libtests/pngvalid.c
+++ /dev/null
@@ -1,10145 +0,0 @@
-
-/* pngvalid.c - validate libpng by constructing then reading png files.
- *
- * Last changed in libpng 1.6.1 [March 28, 2013]
- * Copyright (c) 2013 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
-
-/* 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_WRITE_SUPPORTED /* else pngvalid can do nothing */
-
-#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 <zlib.h> /* For crc32 */
-
-#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
-
-/******************************* 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 */
-}
-
-#ifdef PNG_READ_RGB_TO_GRAY_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) ((int)(((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)
-{
- if (*bit_depth == 0)
- {
- *colour_type = 0, *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)
-{
- 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)
- return (result << 8) + *++row;
-
- /* Less than 8 bits per sample. */
- bit_index &= 7;
- return (result >> (8-bit_index-bit_depth)) & ((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;
- 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;
-}
-
-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
-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
-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
-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
-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
-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*** ***************************/
-/* 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
-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
-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);
-}
-
-/* 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.
- */
- store_pool_delete(ps, &ps->write_memory_pool);
-
- 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. */
- if (ps->speed)
- ps->pwrite = png_create_write_struct(PNG_LIBPNG_VER_STRING,
- ps, store_error, store_warning);
-
- else
- ps->pwrite = png_create_write_struct_2(PNG_LIBPNG_VER_STRING,
- ps, store_error, store_warning, &ps->write_memory_pool,
- store_malloc, store_free);
-
- png_set_write_fn(ps->pwrite, ps, store_write, store_flush);
-
- 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
-
- /* Always do this to be safe. */
- store_pool_delete(ps, &ps->read_memory_pool);
-
- 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.
- */
- if (ps->speed)
- ps->pread = png_create_read_struct(PNG_LIBPNG_VER_STRING, ps,
- store_error, store_warning);
-
- else
- ps->pread = png_create_read_struct_2(PNG_LIBPNG_VER_STRING, ps,
- store_error, store_warning, &ps->read_memory_pool, store_malloc,
- store_free);
-
- 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;
- }
-
- 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 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 combiniation of transforms, */
- unsigned int test_transform :1;
-
- /* When to use the use_input_precision option: */
- 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 both input
- * and output are 8 bit or less.
- */
- 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->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->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
-/* If pm->calculations_use_input_precision is set then operations will happen
- * with only 8 bit precision unless both the input and output bit depth are 16.
- *
- * 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
-static double digitize(PNG_CONST png_modifier *pm, double value,
- int sample_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 =
- (pm->assume_16_bit_calculations || sample_depth == 16) ? 65535 : 255;
-
- /* 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
-
-#if defined(PNG_READ_GAMMA_SUPPORTED) ||\
- defined(PNG_READ_RGB_TO_GRAY_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 || (out_depth == 16 && (in_depth == 16 ||
- !pm->calculations_use_input_precision)))
- return pm->maxabs16;
- else
- return pm->maxabs8;
-}
-#endif
-
-#ifdef PNG_READ_GAMMA_SUPPORTED
-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->assume_16_bit_calculations || (out_depth == 16 && (in_depth == 16 ||
- !pm->calculations_use_input_precision)))
- return pm->maxcalc16;
- 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 || (out_depth == 16 && (in_depth == 16 ||
- !pm->calculations_use_input_precision)))
- 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 (out_depth == 16 && (in_depth == 16 ||
- !pm->calculations_use_input_precision))
- 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 (out_depth == 16 && (in_depth == 16 ||
- !pm->calculations_use_input_precision))
- {
- 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
-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.
- *
- * 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;
-
- if (j > 0)
- png_set_tRNS(pp, pi, tRNS, j, 0/*color*/);
- }
-}
-
-/* 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)))
-
-/* 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);
-
- 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))
- {
- int interlace_type;
-
- for (interlace_type = PNG_INTERLACE_NONE;
- interlace_type < PNG_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);
-
- 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;
- 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;
- }
-
- /* Only get to here if the row has some pixels in it. */
- 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);
- 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);
- }
- }
- }
-}
-
-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);
-
- 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 < PNG_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<(sizeof error_test)/(sizeof error_test[0]); ++test)
- {
- make_error(&pm->this, colour_type, DEPTH(bdlo), interlace_type,
- test, name);
-
- if (fail(pm))
- return 0;
- }
- }
- }
-
- return 1; /* keep going */
-}
-#endif
-
-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;
- int interlace_type;
- 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);
- 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. */
- dp->pixel_size = bit_size(pp, png_get_color_type(pp, pi),
- png_get_bit_depth(pp, pi));
- 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
-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
-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)
-{
- 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);
- 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) ((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
-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);
- 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);
- 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 < PNG_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;
-
- 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;
-
- /* 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;
-
- 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;
- }
- }
-
- 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 */
- int have_tRNS; /* tRNS chunk may need processing */
-
- /* 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.
- */
- 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 max)
-{
- this->redf = this->red / (double)max;
- this->greenf = this->green / (double)max;
- this->bluef = this->blue / (double)max;
- this->alphaf = this->alpha / (double)max;
-
- if (this->red < max)
- this->rede = this->redf * DBL_EPSILON;
- else
- this->rede = 0;
- if (this->green < max)
- this->greene = this->greenf * DBL_EPSILON;
- else
- this->greene = 0;
- if (this->blue < max)
- this->bluee = this->bluef * DBL_EPSILON;
- else
- this->bluee = 0;
- if (this->alpha < max)
- 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 png_byte sample_depth = (png_byte)(colour_type ==
- PNG_COLOR_TYPE_PALETTE ? 8 : bit_depth);
- PNG_CONST unsigned int max = (1U<<sample_depth)-1;
-
- /* 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);
- 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 & 2)
- {
- this->green = sample(row, colour_type, bit_depth, x, 1);
- this->blue = sample(row, colour_type, bit_depth, x, 2);
- i = 2;
- }
- if (colour_type & 4)
- this->alpha = sample(row, colour_type, bit_depth, x, ++i);
- }
-
- /* 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, 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;
-}
-
-/* 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;
-
- /* 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;
-
- 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);
-
- /* 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);
- that->blue = sample_scale(that->bluef, scale);
- 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->alpha = 1; /* Override this. */
- that->alphae = 0; /* It's exact ;-) */
- }
-}
-
-/* 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 */
-}
-
-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);
-
- /* 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.
- */
- {
- 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;
- 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.
- * I believe these are both internal errors.
- */
- if (test_pixel.colour_type == PNG_COLOR_TYPE_PALETTE)
- {
- if (test_pixel.sample_depth != 8) /* oops - internal error! */
- png_error(pp, "pngvalid: internal: palette sample depth not 8");
- }
- else if (test_pixel.sample_depth != dp->output_bit_depth)
- {
- char message[128];
- size_t pos = safecat(message, sizeof message, 0,
- "internal: sample 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.sample_depth);
-
- png_error(pp, message);
- }
- }
-}
-
-static void
-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);
-
- /* assume-8-bit-calculations 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.
- *
- * TODO: fix this in libpng; png_set_expand_16 should cause 16 bit
- * calculations to be used throughout.
- */
- 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 errors are at 8 bit precision, 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);
-
- 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;
-
- /* For error detection, below. */
- r = in_pixel.red;
- g = in_pixel.green;
- b = in_pixel.blue;
- a = in_pixel.alpha;
-
- 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.
- */
- image_pixel_init(&out_pixel, pRow, out_ct, out_bd, x, out_palette);
-
- /* 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
-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((png_modifier*)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 16 bit case ends up producing a maximum error of about
- * +/-5 in 65535, allow for +/-8 with the given gamma.
- */
- that->pm->limit += pow(8./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.
- */
- that->pm->limit += pow(1./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)
- 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... */
- {
- PNG_CONST png_modifier *pm = display->pm;
- PNG_CONST unsigned int sample_depth = that->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(pm, rlo, sample_depth, 1/*round*/);
- rhi += that->rede;
- rhi = digitize(pm, rhi, sample_depth, 1/*round*/);
-
- g = glo = ghi = that->greenf;
- glo -= that->greene;
- glo = digitize(pm, glo, sample_depth, 1/*round*/);
- ghi += that->greene;
- ghi = digitize(pm, ghi, sample_depth, 1/*round*/);
-
- b = blo = bhi = that->bluef;
- blo -= that->bluee;
- blo = digitize(pm, blo, sample_depth, 1/*round*/);
- bhi += that->greene;
- bhi = digitize(pm, bhi, sample_depth, 1/*round*/);
-
- isgray = r==g && g==b;
-
- if (data.gamma != 1)
- {
- PNG_CONST double power = 1/data.gamma;
- PNG_CONST double abse = abserr(pm, sample_depth, sample_depth);
-
- /* '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(pm, pow(rlo, power)-abse, sample_depth, 1);
- rhi = digitize(pm, pow(rhi, power)+abse, sample_depth, 1);
-
- g = pow(g, power);
- glo = digitize(pm, pow(glo, power)-abse, sample_depth, 1);
- ghi = digitize(pm, pow(ghi, power)+abse, sample_depth, 1);
-
- b = pow(b, power);
- blo = digitize(pm, pow(blo, power)-abse, sample_depth, 1);
- bhi = digitize(pm, pow(bhi, power)+abse, sample_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 || sample_depth == 16;
- PNG_CONST double ce = 1. / 32768;
-
- graylo = digitize(pm, rlo * (data.red_coefficient-ce) +
- glo * (data.green_coefficient-ce) +
- blo * (data.blue_coefficient-ce), sample_depth, do_round);
- if (graylo <= 0)
- graylo = 0;
-
- grayhi = digitize(pm, rhi * (data.red_coefficient+ce) +
- ghi * (data.green_coefficient+ce) +
- bhi * (data.blue_coefficient+ce), sample_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(pm, pow(graylo, power), sample_depth, 1);
- grayhi = digitize(pm, 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 > display->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,
- display->pm->limit, 6);
- png_error(pp, buffer);
- }
- }
- }
-
- 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)
- *
- * As with rgb_to_gray 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 */
- 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;
- }
-
- else
- bit_depth = that->this.bit_depth;
-
- image_pixel_init(&data, random_bytes, colour_type,
- bit_depth, 0/*x*/, 0/*unused: palette*/);
-
- /* 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, 1/*need expand*/,
- 0);
-# else
- png_set_background_fixed(pp, &back, PNG_BACKGROUND_GAMMA_FILE,
- 1/*need 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 */
-
-/* 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(1);
- }
-}
-
-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(1);
-}
-
-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;
- }
-}
-
-#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, char *name, size_t sizeof_name,
- size_t *pos, png_byte colour_type, png_byte bit_depth)
-{
- this->next = *that;
- *that = this;
-
- *pos = safecat(name, sizeof_name, *pos, " +@");
-
- return 1;
-}
-
-IT(@);
-#endif
-
-/* 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 */
-/*NOTE: TBD NYI */
-
-/* png_set_bgr */
-/*NOTE: TBD NYI */
-
-/* png_set_swap_alpha */
-/*NOTE: TBD NYI */
-
-/* png_set_swap */
-/*NOTE: TBD NYI */
-
-/* png_set_filler, (png_structp png_ptr, png_uint_32 filler, int flags)); */
-/*NOTE: TBD NYI */
-
-/* png_set_add_alpha, (png_structp png_ptr, png_uint_32 filler, int flags)); */
-/*NOTE: TBD NYI */
-
-/* png_set_packing */
-/*NOTE: TBD NYI */
-
-/* png_set_packswap */
-/*NOTE: TBD NYI */
-
-/* png_set_invert_mono */
-/*NOTE: TBD NYI */
-
-/* png_set_shift(png_structp, png_const_color_8p true_bits) */
-/*NOTE: TBD NYI */
-
-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))
- {
- 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
-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)
- {
- /* 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.
- */
- double tmp = (isbit - .5)/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 + .5)/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_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 below.
- */
- 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) : 256;
- PNG_CONST unsigned int out_index =
- out_ct == 3 ? sample(std, 3, out_bd, x, 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);
-
- 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);
-
- 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),
- sample(pRow, out_ct, out_bd, x, 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),
- out_ct == 3 ? out_palette[out_index].red :
- sample(pRow, out_ct, out_bd, x, 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),
- out_ct == 3 ? out_palette[out_index].green :
- sample(pRow, out_ct, out_bd, x, 1),
- 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),
- out_ct == 3 ? out_palette[out_index].blue :
- sample(pRow, out_ct, out_bd, x, 2),
- 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
-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((png_modifier*)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))
- 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))
- {
- 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))
- 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
- /* 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], PNG_MAX_GAMMA_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], PNG_MAX_GAMMA_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], PNG_MAX_GAMMA_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], PNG_MAX_GAMMA_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);
- }
-
- 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))
- 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)
-{
- pm->error_gray_2 = pm->error_gray_4 = pm->error_gray_8 = 0;
- pm->error_color_8 = 0;
- pm->error_indexed = 0;
- pm->error_gray_16 = pm->error_color_16 = 0;
-}
-
-static void
-summarize_gamma_errors(png_modifier *pm, png_const_charp who, int low_bit_depth)
-{
- if (who)
- printf("Gamma correction with %s:\n", who);
-
- if (low_bit_depth)
- {
- printf(" 2 bit gray: %.5f\n", pm->error_gray_2);
- printf(" 4 bit gray: %.5f\n", pm->error_gray_4);
- printf(" 8 bit gray: %.5f\n", pm->error_gray_8);
- printf(" 8 bit color: %.5f\n", pm->error_color_8);
- printf(" indexed: %.5f\n", pm->error_indexed);
- }
-
-#ifdef DO_16BIT
- printf(" 16 bit gray: %.5f\n", pm->error_gray_16);
- printf(" 16 bit color: %.5f\n", pm->error_color_16);
-#endif
-}
-
-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)
- {
- 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)
- {
- 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\n");
-
- summarize_gamma_errors(pm, 0/*who*/, 1);
- }
- }
-
- /* 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);
- }
-
-#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)
- {
- printf("Gamma 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);
- }
- }
-#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);
- }
-#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);
- }
-#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(1);
- }
-
- 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(1);
- }
-
- 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(1);
- }
-
- 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(1);
- }
-
- /* 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(1);
- }
-
- 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(1);
- }
-
- 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(1);
- }
-
- 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(1);
- }
-
- /* 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(1);
- }
-
- 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(1);
- }
-
- /* 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;
-
- /* Store the test gammas */
- pm.gammas = gammas;
- pm.ngammas = (sizeof gammas) / (sizeof gammas[0]);
- pm.ngamma_tests = 0; /* default to off */
-
- /* And the test encodings */
- pm.encodings = test_encodings;
- pm.nencodings = (sizeof test_encodings) / (sizeof test_encodings[0]);
-
- 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.
- *
- * TODO: review this
- */
- pm.use_input_precision_16to8 = 1U;
-
- /* 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 = .004; /* +/-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 =.000015;/* +/-1 in 16 bits for compose errors */
-
- /* 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)
- pm.interlace_type = PNG_INTERLACE_ADAM7;
-
- else if (strcmp(*argv, "--use-input-precision") == 0)
- pm.use_input_precision = 1;
-
- else if (strcmp(*argv, "--calculations-use-input-precision") == 0)
- pm.calculations_use_input_precision = 1;
-
- else if (strcmp(*argv, "--assume-16-bit-calculations") == 0)
- pm.assume_16_bit_calculations = 1;
-
- 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(1);
- }
-
- 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;
-
- else
- {
- fprintf(stderr, "pngvalid: %s: unknown argument\n", *argv);
- exit(1);
- }
-
- 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);
- }
- }
-
- return 0;
-}
-#else /* write not supported */
-int main(void)
-{
- fprintf(stderr, "pngvalid: no write support in libpng, all tests skipped\n");
- /* So the test is skipped: */
- return 77;
-}
-#endif