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-rw-r--r--src/3rdparty/libpng/pngrtran.c4381
1 files changed, 0 insertions, 4381 deletions
diff --git a/src/3rdparty/libpng/pngrtran.c b/src/3rdparty/libpng/pngrtran.c
deleted file mode 100644
index d7e6b4a..0000000
--- a/src/3rdparty/libpng/pngrtran.c
+++ /dev/null
@@ -1,4381 +0,0 @@
-
-/* pngrtran.c - transforms the data in a row for PNG readers
- *
- * Last changed in libpng 1.2.38 [July 16, 2009]
- * Copyright (c) 1998-2009 Glenn Randers-Pehrson
- * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
- * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
- *
- * This code is released under the libpng license.
- * For conditions of distribution and use, see the disclaimer
- * and license in png.h
- *
- * This file contains functions optionally called by an application
- * in order to tell libpng how to handle data when reading a PNG.
- * Transformations that are used in both reading and writing are
- * in pngtrans.c.
- */
-
-#define PNG_INTERNAL
-#include "png.h"
-#if defined(PNG_READ_SUPPORTED)
-
-/* Set the action on getting a CRC error for an ancillary or critical chunk. */
-void PNGAPI
-png_set_crc_action(png_structp png_ptr, int crit_action, int ancil_action)
-{
- png_debug(1, "in png_set_crc_action");
- /* Tell libpng how we react to CRC errors in critical chunks */
- if (png_ptr == NULL)
- return;
- switch (crit_action)
- {
- case PNG_CRC_NO_CHANGE: /* Leave setting as is */
- break;
-
- case PNG_CRC_WARN_USE: /* Warn/use data */
- png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK;
- png_ptr->flags |= PNG_FLAG_CRC_CRITICAL_USE;
- break;
-
- case PNG_CRC_QUIET_USE: /* Quiet/use data */
- png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK;
- png_ptr->flags |= PNG_FLAG_CRC_CRITICAL_USE |
- PNG_FLAG_CRC_CRITICAL_IGNORE;
- break;
-
- case PNG_CRC_WARN_DISCARD: /* Not a valid action for critical data */
- png_warning(png_ptr,
- "Can't discard critical data on CRC error.");
- case PNG_CRC_ERROR_QUIT: /* Error/quit */
-
- case PNG_CRC_DEFAULT:
- default:
- png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK;
- break;
- }
-
- switch (ancil_action)
- {
- case PNG_CRC_NO_CHANGE: /* Leave setting as is */
- break;
-
- case PNG_CRC_WARN_USE: /* Warn/use data */
- png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK;
- png_ptr->flags |= PNG_FLAG_CRC_ANCILLARY_USE;
- break;
-
- case PNG_CRC_QUIET_USE: /* Quiet/use data */
- png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK;
- png_ptr->flags |= PNG_FLAG_CRC_ANCILLARY_USE |
- PNG_FLAG_CRC_ANCILLARY_NOWARN;
- break;
-
- case PNG_CRC_ERROR_QUIT: /* Error/quit */
- png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK;
- png_ptr->flags |= PNG_FLAG_CRC_ANCILLARY_NOWARN;
- break;
-
- case PNG_CRC_WARN_DISCARD: /* Warn/discard data */
-
- case PNG_CRC_DEFAULT:
- default:
- png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK;
- break;
- }
-}
-
-#if defined(PNG_READ_BACKGROUND_SUPPORTED) && \
- defined(PNG_FLOATING_POINT_SUPPORTED)
-/* Handle alpha and tRNS via a background color */
-void PNGAPI
-png_set_background(png_structp png_ptr,
- png_color_16p background_color, int background_gamma_code,
- int need_expand, double background_gamma)
-{
- png_debug(1, "in png_set_background");
- if (png_ptr == NULL)
- return;
- if (background_gamma_code == PNG_BACKGROUND_GAMMA_UNKNOWN)
- {
- png_warning(png_ptr, "Application must supply a known background gamma");
- return;
- }
-
- png_ptr->transformations |= PNG_BACKGROUND;
- png_memcpy(&(png_ptr->background), background_color,
- png_sizeof(png_color_16));
- png_ptr->background_gamma = (float)background_gamma;
- png_ptr->background_gamma_type = (png_byte)(background_gamma_code);
- png_ptr->transformations |= (need_expand ? PNG_BACKGROUND_EXPAND : 0);
-}
-#endif
-
-#if defined(PNG_READ_16_TO_8_SUPPORTED)
-/* Strip 16 bit depth files to 8 bit depth */
-void PNGAPI
-png_set_strip_16(png_structp png_ptr)
-{
- png_debug(1, "in png_set_strip_16");
- if (png_ptr == NULL)
- return;
- png_ptr->transformations |= PNG_16_TO_8;
-}
-#endif
-
-#if defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
-void PNGAPI
-png_set_strip_alpha(png_structp png_ptr)
-{
- png_debug(1, "in png_set_strip_alpha");
- if (png_ptr == NULL)
- return;
- png_ptr->flags |= PNG_FLAG_STRIP_ALPHA;
-}
-#endif
-
-#if defined(PNG_READ_DITHER_SUPPORTED)
-/* Dither file to 8 bit. Supply a palette, the current number
- * of elements in the palette, the maximum number of elements
- * allowed, and a histogram if possible. If the current number
- * of colors is greater then the maximum number, the palette will be
- * modified to fit in the maximum number. "full_dither" indicates
- * whether we need a dithering cube set up for RGB images, or if we
- * simply are reducing the number of colors in a paletted image.
- */
-
-typedef struct png_dsort_struct
-{
- struct png_dsort_struct FAR * next;
- png_byte left;
- png_byte right;
-} png_dsort;
-typedef png_dsort FAR * png_dsortp;
-typedef png_dsort FAR * FAR * png_dsortpp;
-
-void PNGAPI
-png_set_dither(png_structp png_ptr, png_colorp palette,
- int num_palette, int maximum_colors, png_uint_16p histogram,
- int full_dither)
-{
- png_debug(1, "in png_set_dither");
- if (png_ptr == NULL)
- return;
- png_ptr->transformations |= PNG_DITHER;
-
- if (!full_dither)
- {
- int i;
-
- png_ptr->dither_index = (png_bytep)png_malloc(png_ptr,
- (png_uint_32)(num_palette * png_sizeof(png_byte)));
- for (i = 0; i < num_palette; i++)
- png_ptr->dither_index[i] = (png_byte)i;
- }
-
- if (num_palette > maximum_colors)
- {
- if (histogram != NULL)
- {
- /* This is easy enough, just throw out the least used colors.
- * Perhaps not the best solution, but good enough.
- */
-
- int i;
-
- /* Initialize an array to sort colors */
- png_ptr->dither_sort = (png_bytep)png_malloc(png_ptr,
- (png_uint_32)(num_palette * png_sizeof(png_byte)));
-
- /* Initialize the dither_sort array */
- for (i = 0; i < num_palette; i++)
- png_ptr->dither_sort[i] = (png_byte)i;
-
- /* Find the least used palette entries by starting a
- * bubble sort, and running it until we have sorted
- * out enough colors. Note that we don't care about
- * sorting all the colors, just finding which are
- * least used.
- */
-
- for (i = num_palette - 1; i >= maximum_colors; i--)
- {
- int done; /* To stop early if the list is pre-sorted */
- int j;
-
- done = 1;
- for (j = 0; j < i; j++)
- {
- if (histogram[png_ptr->dither_sort[j]]
- < histogram[png_ptr->dither_sort[j + 1]])
- {
- png_byte t;
-
- t = png_ptr->dither_sort[j];
- png_ptr->dither_sort[j] = png_ptr->dither_sort[j + 1];
- png_ptr->dither_sort[j + 1] = t;
- done = 0;
- }
- }
- if (done)
- break;
- }
-
- /* Swap the palette around, and set up a table, if necessary */
- if (full_dither)
- {
- int j = num_palette;
-
- /* Put all the useful colors within the max, but don't
- * move the others.
- */
- for (i = 0; i < maximum_colors; i++)
- {
- if ((int)png_ptr->dither_sort[i] >= maximum_colors)
- {
- do
- j--;
- while ((int)png_ptr->dither_sort[j] >= maximum_colors);
- palette[i] = palette[j];
- }
- }
- }
- else
- {
- int j = num_palette;
-
- /* Move all the used colors inside the max limit, and
- * develop a translation table.
- */
- for (i = 0; i < maximum_colors; i++)
- {
- /* Only move the colors we need to */
- if ((int)png_ptr->dither_sort[i] >= maximum_colors)
- {
- png_color tmp_color;
-
- do
- j--;
- while ((int)png_ptr->dither_sort[j] >= maximum_colors);
-
- tmp_color = palette[j];
- palette[j] = palette[i];
- palette[i] = tmp_color;
- /* Indicate where the color went */
- png_ptr->dither_index[j] = (png_byte)i;
- png_ptr->dither_index[i] = (png_byte)j;
- }
- }
-
- /* Find closest color for those colors we are not using */
- for (i = 0; i < num_palette; i++)
- {
- if ((int)png_ptr->dither_index[i] >= maximum_colors)
- {
- int min_d, k, min_k, d_index;
-
- /* Find the closest color to one we threw out */
- d_index = png_ptr->dither_index[i];
- min_d = PNG_COLOR_DIST(palette[d_index], palette[0]);
- for (k = 1, min_k = 0; k < maximum_colors; k++)
- {
- int d;
-
- d = PNG_COLOR_DIST(palette[d_index], palette[k]);
-
- if (d < min_d)
- {
- min_d = d;
- min_k = k;
- }
- }
- /* Point to closest color */
- png_ptr->dither_index[i] = (png_byte)min_k;
- }
- }
- }
- png_free(png_ptr, png_ptr->dither_sort);
- png_ptr->dither_sort = NULL;
- }
- else
- {
- /* This is much harder to do simply (and quickly). Perhaps
- * we need to go through a median cut routine, but those
- * don't always behave themselves with only a few colors
- * as input. So we will just find the closest two colors,
- * and throw out one of them (chosen somewhat randomly).
- * [We don't understand this at all, so if someone wants to
- * work on improving it, be our guest - AED, GRP]
- */
- int i;
- int max_d;
- int num_new_palette;
- png_dsortp t;
- png_dsortpp hash;
-
- t = NULL;
-
- /* Initialize palette index arrays */
- png_ptr->index_to_palette = (png_bytep)png_malloc(png_ptr,
- (png_uint_32)(num_palette * png_sizeof(png_byte)));
- png_ptr->palette_to_index = (png_bytep)png_malloc(png_ptr,
- (png_uint_32)(num_palette * png_sizeof(png_byte)));
-
- /* Initialize the sort array */
- for (i = 0; i < num_palette; i++)
- {
- png_ptr->index_to_palette[i] = (png_byte)i;
- png_ptr->palette_to_index[i] = (png_byte)i;
- }
-
- hash = (png_dsortpp)png_malloc(png_ptr, (png_uint_32)(769 *
- png_sizeof(png_dsortp)));
- png_memset(hash, 0, 769 * png_sizeof(png_dsortp));
-
- num_new_palette = num_palette;
-
- /* Initial wild guess at how far apart the farthest pixel
- * pair we will be eliminating will be. Larger
- * numbers mean more areas will be allocated, Smaller
- * numbers run the risk of not saving enough data, and
- * having to do this all over again.
- *
- * I have not done extensive checking on this number.
- */
- max_d = 96;
-
- while (num_new_palette > maximum_colors)
- {
- for (i = 0; i < num_new_palette - 1; i++)
- {
- int j;
-
- for (j = i + 1; j < num_new_palette; j++)
- {
- int d;
-
- d = PNG_COLOR_DIST(palette[i], palette[j]);
-
- if (d <= max_d)
- {
-
- t = (png_dsortp)png_malloc_warn(png_ptr,
- (png_uint_32)(png_sizeof(png_dsort)));
- if (t == NULL)
- break;
- t->next = hash[d];
- t->left = (png_byte)i;
- t->right = (png_byte)j;
- hash[d] = t;
- }
- }
- if (t == NULL)
- break;
- }
-
- if (t != NULL)
- for (i = 0; i <= max_d; i++)
- {
- if (hash[i] != NULL)
- {
- png_dsortp p;
-
- for (p = hash[i]; p; p = p->next)
- {
- if ((int)png_ptr->index_to_palette[p->left]
- < num_new_palette &&
- (int)png_ptr->index_to_palette[p->right]
- < num_new_palette)
- {
- int j, next_j;
-
- if (num_new_palette & 0x01)
- {
- j = p->left;
- next_j = p->right;
- }
- else
- {
- j = p->right;
- next_j = p->left;
- }
-
- num_new_palette--;
- palette[png_ptr->index_to_palette[j]]
- = palette[num_new_palette];
- if (!full_dither)
- {
- int k;
-
- for (k = 0; k < num_palette; k++)
- {
- if (png_ptr->dither_index[k] ==
- png_ptr->index_to_palette[j])
- png_ptr->dither_index[k] =
- png_ptr->index_to_palette[next_j];
- if ((int)png_ptr->dither_index[k] ==
- num_new_palette)
- png_ptr->dither_index[k] =
- png_ptr->index_to_palette[j];
- }
- }
-
- png_ptr->index_to_palette[png_ptr->palette_to_index
- [num_new_palette]] = png_ptr->index_to_palette[j];
- png_ptr->palette_to_index[png_ptr->index_to_palette[j]]
- = png_ptr->palette_to_index[num_new_palette];
-
- png_ptr->index_to_palette[j] = (png_byte)num_new_palette;
- png_ptr->palette_to_index[num_new_palette] = (png_byte)j;
- }
- if (num_new_palette <= maximum_colors)
- break;
- }
- if (num_new_palette <= maximum_colors)
- break;
- }
- }
-
- for (i = 0; i < 769; i++)
- {
- if (hash[i] != NULL)
- {
- png_dsortp p = hash[i];
- while (p)
- {
- t = p->next;
- png_free(png_ptr, p);
- p = t;
- }
- }
- hash[i] = 0;
- }
- max_d += 96;
- }
- png_free(png_ptr, hash);
- png_free(png_ptr, png_ptr->palette_to_index);
- png_free(png_ptr, png_ptr->index_to_palette);
- png_ptr->palette_to_index = NULL;
- png_ptr->index_to_palette = NULL;
- }
- num_palette = maximum_colors;
- }
- if (png_ptr->palette == NULL)
- {
- png_ptr->palette = palette;
- }
- png_ptr->num_palette = (png_uint_16)num_palette;
-
- if (full_dither)
- {
- int i;
- png_bytep distance;
- int total_bits = PNG_DITHER_RED_BITS + PNG_DITHER_GREEN_BITS +
- PNG_DITHER_BLUE_BITS;
- int num_red = (1 << PNG_DITHER_RED_BITS);
- int num_green = (1 << PNG_DITHER_GREEN_BITS);
- int num_blue = (1 << PNG_DITHER_BLUE_BITS);
- png_size_t num_entries = ((png_size_t)1 << total_bits);
- png_ptr->palette_lookup = (png_bytep )png_malloc(png_ptr,
- (png_uint_32)(num_entries * png_sizeof(png_byte)));
- png_memset(png_ptr->palette_lookup, 0, num_entries *
- png_sizeof(png_byte));
-
- distance = (png_bytep)png_malloc(png_ptr, (png_uint_32)(num_entries *
- png_sizeof(png_byte)));
-
- png_memset(distance, 0xff, num_entries * png_sizeof(png_byte));
-
- for (i = 0; i < num_palette; i++)
- {
- int ir, ig, ib;
- int r = (palette[i].red >> (8 - PNG_DITHER_RED_BITS));
- int g = (palette[i].green >> (8 - PNG_DITHER_GREEN_BITS));
- int b = (palette[i].blue >> (8 - PNG_DITHER_BLUE_BITS));
-
- for (ir = 0; ir < num_red; ir++)
- {
- /* int dr = abs(ir - r); */
- int dr = ((ir > r) ? ir - r : r - ir);
- int index_r = (ir << (PNG_DITHER_BLUE_BITS + PNG_DITHER_GREEN_BITS));
-
- for (ig = 0; ig < num_green; ig++)
- {
- /* int dg = abs(ig - g); */
- int dg = ((ig > g) ? ig - g : g - ig);
- int dt = dr + dg;
- int dm = ((dr > dg) ? dr : dg);
- int index_g = index_r | (ig << PNG_DITHER_BLUE_BITS);
-
- for (ib = 0; ib < num_blue; ib++)
- {
- int d_index = index_g | ib;
- /* int db = abs(ib - b); */
- int db = ((ib > b) ? ib - b : b - ib);
- int dmax = ((dm > db) ? dm : db);
- int d = dmax + dt + db;
-
- if (d < (int)distance[d_index])
- {
- distance[d_index] = (png_byte)d;
- png_ptr->palette_lookup[d_index] = (png_byte)i;
- }
- }
- }
- }
- }
-
- png_free(png_ptr, distance);
- }
-}
-#endif
-
-#if defined(PNG_READ_GAMMA_SUPPORTED) && defined(PNG_FLOATING_POINT_SUPPORTED)
-/* Transform the image from the file_gamma to the screen_gamma. We
- * only do transformations on images where the file_gamma and screen_gamma
- * are not close reciprocals, otherwise it slows things down slightly, and
- * also needlessly introduces small errors.
- *
- * We will turn off gamma transformation later if no semitransparent entries
- * are present in the tRNS array for palette images. We can't do it here
- * because we don't necessarily have the tRNS chunk yet.
- */
-void PNGAPI
-png_set_gamma(png_structp png_ptr, double scrn_gamma, double file_gamma)
-{
- png_debug(1, "in png_set_gamma");
- if (png_ptr == NULL)
- return;
- if ((fabs(scrn_gamma * file_gamma - 1.0) > PNG_GAMMA_THRESHOLD) ||
- (png_ptr->color_type & PNG_COLOR_MASK_ALPHA) ||
- (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE))
- png_ptr->transformations |= PNG_GAMMA;
- png_ptr->gamma = (float)file_gamma;
- png_ptr->screen_gamma = (float)scrn_gamma;
-}
-#endif
-
-#if defined(PNG_READ_EXPAND_SUPPORTED)
-/* Expand paletted images to RGB, expand grayscale images of
- * less than 8-bit depth to 8-bit depth, and expand tRNS chunks
- * to alpha channels.
- */
-void PNGAPI
-png_set_expand(png_structp png_ptr)
-{
- png_debug(1, "in png_set_expand");
- if (png_ptr == NULL)
- return;
- png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS);
- png_ptr->flags &= ~PNG_FLAG_ROW_INIT;
-}
-
-/* GRR 19990627: the following three functions currently are identical
- * to png_set_expand(). However, it is entirely reasonable that someone
- * might wish to expand an indexed image to RGB but *not* expand a single,
- * fully transparent palette entry to a full alpha channel--perhaps instead
- * convert tRNS to the grayscale/RGB format (16-bit RGB value), or replace
- * the transparent color with a particular RGB value, or drop tRNS entirely.
- * IOW, a future version of the library may make the transformations flag
- * a bit more fine-grained, with separate bits for each of these three
- * functions.
- *
- * More to the point, these functions make it obvious what libpng will be
- * doing, whereas "expand" can (and does) mean any number of things.
- *
- * GRP 20060307: In libpng-1.4.0, png_set_gray_1_2_4_to_8() was modified
- * to expand only the sample depth but not to expand the tRNS to alpha.
- */
-
-/* Expand paletted images to RGB. */
-void PNGAPI
-png_set_palette_to_rgb(png_structp png_ptr)
-{
- png_debug(1, "in png_set_palette_to_rgb");
- if (png_ptr == NULL)
- return;
- png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS);
- png_ptr->flags &= ~PNG_FLAG_ROW_INIT;
-}
-
-#if !defined(PNG_1_0_X)
-/* Expand grayscale images of less than 8-bit depth to 8 bits. */
-void PNGAPI
-png_set_expand_gray_1_2_4_to_8(png_structp png_ptr)
-{
- png_debug(1, "in png_set_expand_gray_1_2_4_to_8");
- if (png_ptr == NULL)
- return;
- png_ptr->transformations |= PNG_EXPAND;
- png_ptr->flags &= ~PNG_FLAG_ROW_INIT;
-}
-#endif
-
-#if defined(PNG_1_0_X) || defined(PNG_1_2_X)
-/* Expand grayscale images of less than 8-bit depth to 8 bits. */
-/* Deprecated as of libpng-1.2.9 */
-void PNGAPI
-png_set_gray_1_2_4_to_8(png_structp png_ptr)
-{
- png_debug(1, "in png_set_gray_1_2_4_to_8");
- if (png_ptr == NULL)
- return;
- png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS);
-}
-#endif
-
-
-/* Expand tRNS chunks to alpha channels. */
-void PNGAPI
-png_set_tRNS_to_alpha(png_structp png_ptr)
-{
- png_debug(1, "in png_set_tRNS_to_alpha");
- png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS);
- png_ptr->flags &= ~PNG_FLAG_ROW_INIT;
-}
-#endif /* defined(PNG_READ_EXPAND_SUPPORTED) */
-
-#if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED)
-void PNGAPI
-png_set_gray_to_rgb(png_structp png_ptr)
-{
- png_debug(1, "in png_set_gray_to_rgb");
- png_ptr->transformations |= PNG_GRAY_TO_RGB;
- png_ptr->flags &= ~PNG_FLAG_ROW_INIT;
-}
-#endif
-
-#if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
-#if defined(PNG_FLOATING_POINT_SUPPORTED)
-/* Convert a RGB image to a grayscale of the same width. This allows us,
- * for example, to convert a 24 bpp RGB image into an 8 bpp grayscale image.
- */
-
-void PNGAPI
-png_set_rgb_to_gray(png_structp png_ptr, int error_action, double red,
- double green)
-{
- int red_fixed = (int)((float)red*100000.0 + 0.5);
- int green_fixed = (int)((float)green*100000.0 + 0.5);
- if (png_ptr == NULL)
- return;
- png_set_rgb_to_gray_fixed(png_ptr, error_action, red_fixed, green_fixed);
-}
-#endif
-
-void PNGAPI
-png_set_rgb_to_gray_fixed(png_structp png_ptr, int error_action,
- png_fixed_point red, png_fixed_point green)
-{
- png_debug(1, "in png_set_rgb_to_gray");
- if (png_ptr == NULL)
- return;
- switch(error_action)
- {
- case 1: png_ptr->transformations |= PNG_RGB_TO_GRAY;
- break;
-
- case 2: png_ptr->transformations |= PNG_RGB_TO_GRAY_WARN;
- break;
-
- case 3: png_ptr->transformations |= PNG_RGB_TO_GRAY_ERR;
- }
- if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
-#if defined(PNG_READ_EXPAND_SUPPORTED)
- png_ptr->transformations |= PNG_EXPAND;
-#else
- {
- png_warning(png_ptr,
- "Cannot do RGB_TO_GRAY without EXPAND_SUPPORTED.");
- png_ptr->transformations &= ~PNG_RGB_TO_GRAY;
- }
-#endif
- {
- png_uint_16 red_int, green_int;
- if (red < 0 || green < 0)
- {
- red_int = 6968; /* .212671 * 32768 + .5 */
- green_int = 23434; /* .715160 * 32768 + .5 */
- }
- else if (red + green < 100000L)
- {
- red_int = (png_uint_16)(((png_uint_32)red*32768L)/100000L);
- green_int = (png_uint_16)(((png_uint_32)green*32768L)/100000L);
- }
- else
- {
- png_warning(png_ptr, "ignoring out of range rgb_to_gray coefficients");
- red_int = 6968;
- green_int = 23434;
- }
- png_ptr->rgb_to_gray_red_coeff = red_int;
- png_ptr->rgb_to_gray_green_coeff = green_int;
- png_ptr->rgb_to_gray_blue_coeff =
- (png_uint_16)(32768 - red_int - green_int);
- }
-}
-#endif
-
-#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
- defined(PNG_LEGACY_SUPPORTED) || \
- defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
-void PNGAPI
-png_set_read_user_transform_fn(png_structp png_ptr, png_user_transform_ptr
- read_user_transform_fn)
-{
- png_debug(1, "in png_set_read_user_transform_fn");
- if (png_ptr == NULL)
- return;
-#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED)
- png_ptr->transformations |= PNG_USER_TRANSFORM;
- png_ptr->read_user_transform_fn = read_user_transform_fn;
-#endif
-#ifdef PNG_LEGACY_SUPPORTED
- if (read_user_transform_fn)
- png_warning(png_ptr,
- "This version of libpng does not support user transforms");
-#endif
-}
-#endif
-
-/* Initialize everything needed for the read. This includes modifying
- * the palette.
- */
-void /* PRIVATE */
-png_init_read_transformations(png_structp png_ptr)
-{
- png_debug(1, "in png_init_read_transformations");
-#if defined(PNG_USELESS_TESTS_SUPPORTED)
- if (png_ptr != NULL)
-#endif
- {
-#if defined(PNG_READ_BACKGROUND_SUPPORTED) || defined(PNG_READ_SHIFT_SUPPORTED) \
- || defined(PNG_READ_GAMMA_SUPPORTED)
- int color_type = png_ptr->color_type;
-#endif
-
-#if defined(PNG_READ_EXPAND_SUPPORTED) && defined(PNG_READ_BACKGROUND_SUPPORTED)
-
-#if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED)
- /* Detect gray background and attempt to enable optimization
- * for gray --> RGB case
- *
- * Note: if PNG_BACKGROUND_EXPAND is set and color_type is either RGB or
- * RGB_ALPHA (in which case need_expand is superfluous anyway), the
- * background color might actually be gray yet not be flagged as such.
- * This is not a problem for the current code, which uses
- * PNG_BACKGROUND_IS_GRAY only to decide when to do the
- * png_do_gray_to_rgb() transformation.
- */
- if ((png_ptr->transformations & PNG_BACKGROUND_EXPAND) &&
- !(color_type & PNG_COLOR_MASK_COLOR))
- {
- png_ptr->mode |= PNG_BACKGROUND_IS_GRAY;
- } else if ((png_ptr->transformations & PNG_BACKGROUND) &&
- !(png_ptr->transformations & PNG_BACKGROUND_EXPAND) &&
- (png_ptr->transformations & PNG_GRAY_TO_RGB) &&
- png_ptr->background.red == png_ptr->background.green &&
- png_ptr->background.red == png_ptr->background.blue)
- {
- png_ptr->mode |= PNG_BACKGROUND_IS_GRAY;
- png_ptr->background.gray = png_ptr->background.red;
- }
-#endif
-
- if ((png_ptr->transformations & PNG_BACKGROUND_EXPAND) &&
- (png_ptr->transformations & PNG_EXPAND))
- {
- if (!(color_type & PNG_COLOR_MASK_COLOR)) /* i.e., GRAY or GRAY_ALPHA */
- {
- /* Expand background and tRNS chunks */
- switch (png_ptr->bit_depth)
- {
- case 1:
- png_ptr->background.gray *= (png_uint_16)0xff;
- png_ptr->background.red = png_ptr->background.green
- = png_ptr->background.blue = png_ptr->background.gray;
- if (!(png_ptr->transformations & PNG_EXPAND_tRNS))
- {
- png_ptr->trans_values.gray *= (png_uint_16)0xff;
- png_ptr->trans_values.red = png_ptr->trans_values.green
- = png_ptr->trans_values.blue = png_ptr->trans_values.gray;
- }
- break;
-
- case 2:
- png_ptr->background.gray *= (png_uint_16)0x55;
- png_ptr->background.red = png_ptr->background.green
- = png_ptr->background.blue = png_ptr->background.gray;
- if (!(png_ptr->transformations & PNG_EXPAND_tRNS))
- {
- png_ptr->trans_values.gray *= (png_uint_16)0x55;
- png_ptr->trans_values.red = png_ptr->trans_values.green
- = png_ptr->trans_values.blue = png_ptr->trans_values.gray;
- }
- break;
-
- case 4:
- png_ptr->background.gray *= (png_uint_16)0x11;
- png_ptr->background.red = png_ptr->background.green
- = png_ptr->background.blue = png_ptr->background.gray;
- if (!(png_ptr->transformations & PNG_EXPAND_tRNS))
- {
- png_ptr->trans_values.gray *= (png_uint_16)0x11;
- png_ptr->trans_values.red = png_ptr->trans_values.green
- = png_ptr->trans_values.blue = png_ptr->trans_values.gray;
- }
- break;
-
- case 8:
-
- case 16:
- png_ptr->background.red = png_ptr->background.green
- = png_ptr->background.blue = png_ptr->background.gray;
- break;
- }
- }
- else if (color_type == PNG_COLOR_TYPE_PALETTE)
- {
- png_ptr->background.red =
- png_ptr->palette[png_ptr->background.index].red;
- png_ptr->background.green =
- png_ptr->palette[png_ptr->background.index].green;
- png_ptr->background.blue =
- png_ptr->palette[png_ptr->background.index].blue;
-
-#if defined(PNG_READ_INVERT_ALPHA_SUPPORTED)
- if (png_ptr->transformations & PNG_INVERT_ALPHA)
- {
-#if defined(PNG_READ_EXPAND_SUPPORTED)
- if (!(png_ptr->transformations & PNG_EXPAND_tRNS))
-#endif
- {
- /* Invert the alpha channel (in tRNS) unless the pixels are
- * going to be expanded, in which case leave it for later
- */
- int i, istop;
- istop=(int)png_ptr->num_trans;
- for (i=0; i<istop; i++)
- png_ptr->trans[i] = (png_byte)(255 - png_ptr->trans[i]);
- }
- }
-#endif
-
- }
- }
-#endif
-
-#if defined(PNG_READ_BACKGROUND_SUPPORTED) && defined(PNG_READ_GAMMA_SUPPORTED)
- png_ptr->background_1 = png_ptr->background;
-#endif
-#if defined(PNG_READ_GAMMA_SUPPORTED) && defined(PNG_FLOATING_POINT_SUPPORTED)
-
- if ((color_type == PNG_COLOR_TYPE_PALETTE && png_ptr->num_trans != 0)
- && (fabs(png_ptr->screen_gamma * png_ptr->gamma - 1.0)
- < PNG_GAMMA_THRESHOLD))
- {
- int i, k;
- k=0;
- for (i=0; i<png_ptr->num_trans; i++)
- {
- if (png_ptr->trans[i] != 0 && png_ptr->trans[i] != 0xff)
- k=1; /* Partial transparency is present */
- }
- if (k == 0)
- png_ptr->transformations &= ~PNG_GAMMA;
- }
-
- if ((png_ptr->transformations & (PNG_GAMMA | PNG_RGB_TO_GRAY)) &&
- png_ptr->gamma != 0.0)
- {
- png_build_gamma_table(png_ptr);
-#if defined(PNG_READ_BACKGROUND_SUPPORTED)
- if (png_ptr->transformations & PNG_BACKGROUND)
- {
- if (color_type == PNG_COLOR_TYPE_PALETTE)
- {
- /* Could skip if no transparency */
- png_color back, back_1;
- png_colorp palette = png_ptr->palette;
- int num_palette = png_ptr->num_palette;
- int i;
- if (png_ptr->background_gamma_type == PNG_BACKGROUND_GAMMA_FILE)
- {
- back.red = png_ptr->gamma_table[png_ptr->background.red];
- back.green = png_ptr->gamma_table[png_ptr->background.green];
- back.blue = png_ptr->gamma_table[png_ptr->background.blue];
-
- back_1.red = png_ptr->gamma_to_1[png_ptr->background.red];
- back_1.green = png_ptr->gamma_to_1[png_ptr->background.green];
- back_1.blue = png_ptr->gamma_to_1[png_ptr->background.blue];
- }
- else
- {
- double g, gs;
-
- switch (png_ptr->background_gamma_type)
- {
- case PNG_BACKGROUND_GAMMA_SCREEN:
- g = (png_ptr->screen_gamma);
- gs = 1.0;
- break;
-
- case PNG_BACKGROUND_GAMMA_FILE:
- g = 1.0 / (png_ptr->gamma);
- gs = 1.0 / (png_ptr->gamma * png_ptr->screen_gamma);
- break;
-
- case PNG_BACKGROUND_GAMMA_UNIQUE:
- g = 1.0 / (png_ptr->background_gamma);
- gs = 1.0 / (png_ptr->background_gamma *
- png_ptr->screen_gamma);
- break;
- default:
- g = 1.0; /* back_1 */
- gs = 1.0; /* back */
- }
-
- if ( fabs(gs - 1.0) < PNG_GAMMA_THRESHOLD)
- {
- back.red = (png_byte)png_ptr->background.red;
- back.green = (png_byte)png_ptr->background.green;
- back.blue = (png_byte)png_ptr->background.blue;
- }
- else
- {
- back.red = (png_byte)(pow(
- (double)png_ptr->background.red/255, gs) * 255.0 + .5);
- back.green = (png_byte)(pow(
- (double)png_ptr->background.green/255, gs) * 255.0 + .5);
- back.blue = (png_byte)(pow(
- (double)png_ptr->background.blue/255, gs) * 255.0 + .5);
- }
-
- back_1.red = (png_byte)(pow(
- (double)png_ptr->background.red/255, g) * 255.0 + .5);
- back_1.green = (png_byte)(pow(
- (double)png_ptr->background.green/255, g) * 255.0 + .5);
- back_1.blue = (png_byte)(pow(
- (double)png_ptr->background.blue/255, g) * 255.0 + .5);
- }
- for (i = 0; i < num_palette; i++)
- {
- if (i < (int)png_ptr->num_trans && png_ptr->trans[i] != 0xff)
- {
- if (png_ptr->trans[i] == 0)
- {
- palette[i] = back;
- }
- else /* if (png_ptr->trans[i] != 0xff) */
- {
- png_byte v, w;
-
- v = png_ptr->gamma_to_1[palette[i].red];
- png_composite(w, v, png_ptr->trans[i], back_1.red);
- palette[i].red = png_ptr->gamma_from_1[w];
-
- v = png_ptr->gamma_to_1[palette[i].green];
- png_composite(w, v, png_ptr->trans[i], back_1.green);
- palette[i].green = png_ptr->gamma_from_1[w];
-
- v = png_ptr->gamma_to_1[palette[i].blue];
- png_composite(w, v, png_ptr->trans[i], back_1.blue);
- palette[i].blue = png_ptr->gamma_from_1[w];
- }
- }
- else
- {
- palette[i].red = png_ptr->gamma_table[palette[i].red];
- palette[i].green = png_ptr->gamma_table[palette[i].green];
- palette[i].blue = png_ptr->gamma_table[palette[i].blue];
- }
- }
- /* Prevent the transformations being done again, and make sure
- * that the now spurious alpha channel is stripped - the code
- * has just reduced background composition and gamma correction
- * to a simple alpha channel strip.
- */
- png_ptr->transformations &= ~PNG_BACKGROUND;
- png_ptr->transformations &= ~PNG_GAMMA;
- png_ptr->transformations |= PNG_STRIP_ALPHA;
- }
- /* if (png_ptr->background_gamma_type!=PNG_BACKGROUND_GAMMA_UNKNOWN) */
- else
- /* color_type != PNG_COLOR_TYPE_PALETTE */
- {
- double m = (double)(((png_uint_32)1 << png_ptr->bit_depth) - 1);
- double g = 1.0;
- double gs = 1.0;
-
- switch (png_ptr->background_gamma_type)
- {
- case PNG_BACKGROUND_GAMMA_SCREEN:
- g = (png_ptr->screen_gamma);
- gs = 1.0;
- break;
-
- case PNG_BACKGROUND_GAMMA_FILE:
- g = 1.0 / (png_ptr->gamma);
- gs = 1.0 / (png_ptr->gamma * png_ptr->screen_gamma);
- break;
-
- case PNG_BACKGROUND_GAMMA_UNIQUE:
- g = 1.0 / (png_ptr->background_gamma);
- gs = 1.0 / (png_ptr->background_gamma *
- png_ptr->screen_gamma);
- break;
- }
-
- png_ptr->background_1.gray = (png_uint_16)(pow(
- (double)png_ptr->background.gray / m, g) * m + .5);
- png_ptr->background.gray = (png_uint_16)(pow(
- (double)png_ptr->background.gray / m, gs) * m + .5);
-
- if ((png_ptr->background.red != png_ptr->background.green) ||
- (png_ptr->background.red != png_ptr->background.blue) ||
- (png_ptr->background.red != png_ptr->background.gray))
- {
- /* RGB or RGBA with color background */
- png_ptr->background_1.red = (png_uint_16)(pow(
- (double)png_ptr->background.red / m, g) * m + .5);
- png_ptr->background_1.green = (png_uint_16)(pow(
- (double)png_ptr->background.green / m, g) * m + .5);
- png_ptr->background_1.blue = (png_uint_16)(pow(
- (double)png_ptr->background.blue / m, g) * m + .5);
- png_ptr->background.red = (png_uint_16)(pow(
- (double)png_ptr->background.red / m, gs) * m + .5);
- png_ptr->background.green = (png_uint_16)(pow(
- (double)png_ptr->background.green / m, gs) * m + .5);
- png_ptr->background.blue = (png_uint_16)(pow(
- (double)png_ptr->background.blue / m, gs) * m + .5);
- }
- else
- {
- /* GRAY, GRAY ALPHA, RGB, or RGBA with gray background */
- png_ptr->background_1.red = png_ptr->background_1.green
- = png_ptr->background_1.blue = png_ptr->background_1.gray;
- png_ptr->background.red = png_ptr->background.green
- = png_ptr->background.blue = png_ptr->background.gray;
- }
- }
- }
- else
- /* Transformation does not include PNG_BACKGROUND */
-#endif /* PNG_READ_BACKGROUND_SUPPORTED */
- if (color_type == PNG_COLOR_TYPE_PALETTE)
- {
- png_colorp palette = png_ptr->palette;
- int num_palette = png_ptr->num_palette;
- int i;
-
- for (i = 0; i < num_palette; i++)
- {
- palette[i].red = png_ptr->gamma_table[palette[i].red];
- palette[i].green = png_ptr->gamma_table[palette[i].green];
- palette[i].blue = png_ptr->gamma_table[palette[i].blue];
- }
-
- /* Done the gamma correction. */
- png_ptr->transformations &= ~PNG_GAMMA;
- }
- }
-#if defined(PNG_READ_BACKGROUND_SUPPORTED)
- else
-#endif
-#endif /* PNG_READ_GAMMA_SUPPORTED && PNG_FLOATING_POINT_SUPPORTED */
-#if defined(PNG_READ_BACKGROUND_SUPPORTED)
- /* No GAMMA transformation */
- if ((png_ptr->transformations & PNG_BACKGROUND) &&
- (color_type == PNG_COLOR_TYPE_PALETTE))
- {
- int i;
- int istop = (int)png_ptr->num_trans;
- png_color back;
- png_colorp palette = png_ptr->palette;
-
- back.red = (png_byte)png_ptr->background.red;
- back.green = (png_byte)png_ptr->background.green;
- back.blue = (png_byte)png_ptr->background.blue;
-
- for (i = 0; i < istop; i++)
- {
- if (png_ptr->trans[i] == 0)
- {
- palette[i] = back;
- }
- else if (png_ptr->trans[i] != 0xff)
- {
- /* The png_composite() macro is defined in png.h */
- png_composite(palette[i].red, palette[i].red,
- png_ptr->trans[i], back.red);
- png_composite(palette[i].green, palette[i].green,
- png_ptr->trans[i], back.green);
- png_composite(palette[i].blue, palette[i].blue,
- png_ptr->trans[i], back.blue);
- }
- }
-
- /* Handled alpha, still need to strip the channel. */
- png_ptr->transformations &= ~PNG_BACKGROUND;
- png_ptr->transformations |= PNG_STRIP_ALPHA;
- }
-#endif /* PNG_READ_BACKGROUND_SUPPORTED */
-
-#if defined(PNG_READ_SHIFT_SUPPORTED)
- if ((png_ptr->transformations & PNG_SHIFT) &&
- (color_type == PNG_COLOR_TYPE_PALETTE))
- {
- png_uint_16 i;
- png_uint_16 istop = png_ptr->num_palette;
- int sr = 8 - png_ptr->sig_bit.red;
- int sg = 8 - png_ptr->sig_bit.green;
- int sb = 8 - png_ptr->sig_bit.blue;
-
- if (sr < 0 || sr > 8)
- sr = 0;
- if (sg < 0 || sg > 8)
- sg = 0;
- if (sb < 0 || sb > 8)
- sb = 0;
- for (i = 0; i < istop; i++)
- {
- png_ptr->palette[i].red >>= sr;
- png_ptr->palette[i].green >>= sg;
- png_ptr->palette[i].blue >>= sb;
- }
- }
-#endif /* PNG_READ_SHIFT_SUPPORTED */
- }
-#if !defined(PNG_READ_GAMMA_SUPPORTED) && !defined(PNG_READ_SHIFT_SUPPORTED) \
- && !defined(PNG_READ_BACKGROUND_SUPPORTED)
- if (png_ptr)
- return;
-#endif
-}
-
-/* Modify the info structure to reflect the transformations. The
- * info should be updated so a PNG file could be written with it,
- * assuming the transformations result in valid PNG data.
- */
-void /* PRIVATE */
-png_read_transform_info(png_structp png_ptr, png_infop info_ptr)
-{
- png_debug(1, "in png_read_transform_info");
-#if defined(PNG_READ_EXPAND_SUPPORTED)
- if (png_ptr->transformations & PNG_EXPAND)
- {
- if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
- {
- if (png_ptr->num_trans &&
- (png_ptr->transformations & PNG_EXPAND_tRNS))
- info_ptr->color_type = PNG_COLOR_TYPE_RGB_ALPHA;
- else
- info_ptr->color_type = PNG_COLOR_TYPE_RGB;
- info_ptr->bit_depth = 8;
- info_ptr->num_trans = 0;
- }
- else
- {
- if (png_ptr->num_trans)
- {
- if (png_ptr->transformations & PNG_EXPAND_tRNS)
- info_ptr->color_type |= PNG_COLOR_MASK_ALPHA;
- }
- if (info_ptr->bit_depth < 8)
- info_ptr->bit_depth = 8;
- info_ptr->num_trans = 0;
- }
- }
-#endif
-
-#if defined(PNG_READ_BACKGROUND_SUPPORTED)
- if (png_ptr->transformations & PNG_BACKGROUND)
- {
- info_ptr->color_type &= ~PNG_COLOR_MASK_ALPHA;
- info_ptr->num_trans = 0;
- info_ptr->background = png_ptr->background;
- }
-#endif
-
-#if defined(PNG_READ_GAMMA_SUPPORTED)
- if (png_ptr->transformations & PNG_GAMMA)
- {
-#ifdef PNG_FLOATING_POINT_SUPPORTED
- info_ptr->gamma = png_ptr->gamma;
-#endif
-#ifdef PNG_FIXED_POINT_SUPPORTED
- info_ptr->int_gamma = png_ptr->int_gamma;
-#endif
- }
-#endif
-
-#if defined(PNG_READ_16_TO_8_SUPPORTED)
- if ((png_ptr->transformations & PNG_16_TO_8) && (info_ptr->bit_depth == 16))
- info_ptr->bit_depth = 8;
-#endif
-
-#if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED)
- if (png_ptr->transformations & PNG_GRAY_TO_RGB)
- info_ptr->color_type |= PNG_COLOR_MASK_COLOR;
-#endif
-
-#if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
- if (png_ptr->transformations & PNG_RGB_TO_GRAY)
- info_ptr->color_type &= ~PNG_COLOR_MASK_COLOR;
-#endif
-
-#if defined(PNG_READ_DITHER_SUPPORTED)
- if (png_ptr->transformations & PNG_DITHER)
- {
- if (((info_ptr->color_type == PNG_COLOR_TYPE_RGB) ||
- (info_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA)) &&
- png_ptr->palette_lookup && info_ptr->bit_depth == 8)
- {
- info_ptr->color_type = PNG_COLOR_TYPE_PALETTE;
- }
- }
-#endif
-
-#if defined(PNG_READ_PACK_SUPPORTED)
- if ((png_ptr->transformations & PNG_PACK) && (info_ptr->bit_depth < 8))
- info_ptr->bit_depth = 8;
-#endif
-
- if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
- info_ptr->channels = 1;
- else if (info_ptr->color_type & PNG_COLOR_MASK_COLOR)
- info_ptr->channels = 3;
- else
- info_ptr->channels = 1;
-
-#if defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
- if (png_ptr->flags & PNG_FLAG_STRIP_ALPHA)
- info_ptr->color_type &= ~PNG_COLOR_MASK_ALPHA;
-#endif
-
- if (info_ptr->color_type & PNG_COLOR_MASK_ALPHA)
- info_ptr->channels++;
-
-#if defined(PNG_READ_FILLER_SUPPORTED)
- /* STRIP_ALPHA and FILLER allowed: MASK_ALPHA bit stripped above */
- if ((png_ptr->transformations & PNG_FILLER) &&
- ((info_ptr->color_type == PNG_COLOR_TYPE_RGB) ||
- (info_ptr->color_type == PNG_COLOR_TYPE_GRAY)))
- {
- info_ptr->channels++;
- /* If adding a true alpha channel not just filler */
-#if !defined(PNG_1_0_X)
- if (png_ptr->transformations & PNG_ADD_ALPHA)
- info_ptr->color_type |= PNG_COLOR_MASK_ALPHA;
-#endif
- }
-#endif
-
-#if defined(PNG_USER_TRANSFORM_PTR_SUPPORTED) && \
-defined(PNG_READ_USER_TRANSFORM_SUPPORTED)
- if (png_ptr->transformations & PNG_USER_TRANSFORM)
- {
- if (info_ptr->bit_depth < png_ptr->user_transform_depth)
- info_ptr->bit_depth = png_ptr->user_transform_depth;
- if (info_ptr->channels < png_ptr->user_transform_channels)
- info_ptr->channels = png_ptr->user_transform_channels;
- }
-#endif
-
- info_ptr->pixel_depth = (png_byte)(info_ptr->channels *
- info_ptr->bit_depth);
-
- info_ptr->rowbytes = PNG_ROWBYTES(info_ptr->pixel_depth, info_ptr->width);
-
-#if !defined(PNG_READ_EXPAND_SUPPORTED)
- if (png_ptr)
- return;
-#endif
-}
-
-/* Transform the row. The order of transformations is significant,
- * and is very touchy. If you add a transformation, take care to
- * decide how it fits in with the other transformations here.
- */
-void /* PRIVATE */
-png_do_read_transformations(png_structp png_ptr)
-{
- png_debug(1, "in png_do_read_transformations");
- if (png_ptr->row_buf == NULL)
- {
-#if !defined(PNG_NO_STDIO) && !defined(_WIN32_WCE)
- char msg[50];
-
- png_snprintf2(msg, 50,
- "NULL row buffer for row %ld, pass %d", (long)png_ptr->row_number,
- png_ptr->pass);
- png_error(png_ptr, msg);
-#else
- png_error(png_ptr, "NULL row buffer");
-#endif
- }
-#ifdef PNG_WARN_UNINITIALIZED_ROW
- if (!(png_ptr->flags & PNG_FLAG_ROW_INIT))
- /* Application has failed to call either png_read_start_image()
- * or png_read_update_info() after setting transforms that expand
- * pixels. This check added to libpng-1.2.19
- */
-#if (PNG_WARN_UNINITIALIZED_ROW==1)
- png_error(png_ptr, "Uninitialized row");
-#else
- png_warning(png_ptr, "Uninitialized row");
-#endif
-#endif
-
-#if defined(PNG_READ_EXPAND_SUPPORTED)
- if (png_ptr->transformations & PNG_EXPAND)
- {
- if (png_ptr->row_info.color_type == PNG_COLOR_TYPE_PALETTE)
- {
- png_do_expand_palette(&(png_ptr->row_info), png_ptr->row_buf + 1,
- png_ptr->palette, png_ptr->trans, png_ptr->num_trans);
- }
- else
- {
- if (png_ptr->num_trans &&
- (png_ptr->transformations & PNG_EXPAND_tRNS))
- png_do_expand(&(png_ptr->row_info), png_ptr->row_buf + 1,
- &(png_ptr->trans_values));
- else
- png_do_expand(&(png_ptr->row_info), png_ptr->row_buf + 1,
- NULL);
- }
- }
-#endif
-
-#if defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
- if (png_ptr->flags & PNG_FLAG_STRIP_ALPHA)
- png_do_strip_filler(&(png_ptr->row_info), png_ptr->row_buf + 1,
- PNG_FLAG_FILLER_AFTER | (png_ptr->flags & PNG_FLAG_STRIP_ALPHA));
-#endif
-
-#if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
- if (png_ptr->transformations & PNG_RGB_TO_GRAY)
- {
- int rgb_error =
- png_do_rgb_to_gray(png_ptr, &(png_ptr->row_info), png_ptr->row_buf + 1);
- if (rgb_error)
- {
- png_ptr->rgb_to_gray_status=1;
- if ((png_ptr->transformations & PNG_RGB_TO_GRAY) ==
- PNG_RGB_TO_GRAY_WARN)
- png_warning(png_ptr, "png_do_rgb_to_gray found nongray pixel");
- if ((png_ptr->transformations & PNG_RGB_TO_GRAY) ==
- PNG_RGB_TO_GRAY_ERR)
- png_error(png_ptr, "png_do_rgb_to_gray found nongray pixel");
- }
- }
-#endif
-
-/* From Andreas Dilger e-mail to png-implement, 26 March 1998:
- *
- * In most cases, the "simple transparency" should be done prior to doing
- * gray-to-RGB, or you will have to test 3x as many bytes to check if a
- * pixel is transparent. You would also need to make sure that the
- * transparency information is upgraded to RGB.
- *
- * To summarize, the current flow is:
- * - Gray + simple transparency -> compare 1 or 2 gray bytes and composite
- * with background "in place" if transparent,
- * convert to RGB if necessary
- * - Gray + alpha -> composite with gray background and remove alpha bytes,
- * convert to RGB if necessary
- *
- * To support RGB backgrounds for gray images we need:
- * - Gray + simple transparency -> convert to RGB + simple transparency,
- * compare 3 or 6 bytes and composite with
- * background "in place" if transparent
- * (3x compare/pixel compared to doing
- * composite with gray bkgrnd)
- * - Gray + alpha -> convert to RGB + alpha, composite with background and
- * remove alpha bytes (3x float
- * operations/pixel compared with composite
- * on gray background)
- *
- * Greg's change will do this. The reason it wasn't done before is for
- * performance, as this increases the per-pixel operations. If we would check
- * in advance if the background was gray or RGB, and position the gray-to-RGB
- * transform appropriately, then it would save a lot of work/time.
- */
-
-#if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED)
- /* If gray -> RGB, do so now only if background is non-gray; else do later
- * for performance reasons
- */
- if ((png_ptr->transformations & PNG_GRAY_TO_RGB) &&
- !(png_ptr->mode & PNG_BACKGROUND_IS_GRAY))
- png_do_gray_to_rgb(&(png_ptr->row_info), png_ptr->row_buf + 1);
-#endif
-
-#if defined(PNG_READ_BACKGROUND_SUPPORTED)
- if ((png_ptr->transformations & PNG_BACKGROUND) &&
- ((png_ptr->num_trans != 0 ) ||
- (png_ptr->color_type & PNG_COLOR_MASK_ALPHA)))
- png_do_background(&(png_ptr->row_info), png_ptr->row_buf + 1,
- &(png_ptr->trans_values), &(png_ptr->background)
-#if defined(PNG_READ_GAMMA_SUPPORTED)
- , &(png_ptr->background_1),
- png_ptr->gamma_table, png_ptr->gamma_from_1,
- png_ptr->gamma_to_1, png_ptr->gamma_16_table,
- png_ptr->gamma_16_from_1, png_ptr->gamma_16_to_1,
- png_ptr->gamma_shift
-#endif
-);
-#endif
-
-#if defined(PNG_READ_GAMMA_SUPPORTED)
- if ((png_ptr->transformations & PNG_GAMMA) &&
-#if defined(PNG_READ_BACKGROUND_SUPPORTED)
- !((png_ptr->transformations & PNG_BACKGROUND) &&
- ((png_ptr->num_trans != 0) ||
- (png_ptr->color_type & PNG_COLOR_MASK_ALPHA))) &&
-#endif
- (png_ptr->color_type != PNG_COLOR_TYPE_PALETTE))
- png_do_gamma(&(png_ptr->row_info), png_ptr->row_buf + 1,
- png_ptr->gamma_table, png_ptr->gamma_16_table,
- png_ptr->gamma_shift);
-#endif
-
-#if defined(PNG_READ_16_TO_8_SUPPORTED)
- if (png_ptr->transformations & PNG_16_TO_8)
- png_do_chop(&(png_ptr->row_info), png_ptr->row_buf + 1);
-#endif
-
-#if defined(PNG_READ_DITHER_SUPPORTED)
- if (png_ptr->transformations & PNG_DITHER)
- {
- png_do_dither((png_row_infop)&(png_ptr->row_info), png_ptr->row_buf + 1,
- png_ptr->palette_lookup, png_ptr->dither_index);
- if (png_ptr->row_info.rowbytes == (png_uint_32)0)
- png_error(png_ptr, "png_do_dither returned rowbytes=0");
- }
-#endif
-
-#if defined(PNG_READ_INVERT_SUPPORTED)
- if (png_ptr->transformations & PNG_INVERT_MONO)
- png_do_invert(&(png_ptr->row_info), png_ptr->row_buf + 1);
-#endif
-
-#if defined(PNG_READ_SHIFT_SUPPORTED)
- if (png_ptr->transformations & PNG_SHIFT)
- png_do_unshift(&(png_ptr->row_info), png_ptr->row_buf + 1,
- &(png_ptr->shift));
-#endif
-
-#if defined(PNG_READ_PACK_SUPPORTED)
- if (png_ptr->transformations & PNG_PACK)
- png_do_unpack(&(png_ptr->row_info), png_ptr->row_buf + 1);
-#endif
-
-#if defined(PNG_READ_BGR_SUPPORTED)
- if (png_ptr->transformations & PNG_BGR)
- png_do_bgr(&(png_ptr->row_info), png_ptr->row_buf + 1);
-#endif
-
-#if defined(PNG_READ_PACKSWAP_SUPPORTED)
- if (png_ptr->transformations & PNG_PACKSWAP)
- png_do_packswap(&(png_ptr->row_info), png_ptr->row_buf + 1);
-#endif
-
-#if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED)
- /* If gray -> RGB, do so now only if we did not do so above */
- if ((png_ptr->transformations & PNG_GRAY_TO_RGB) &&
- (png_ptr->mode & PNG_BACKGROUND_IS_GRAY))
- png_do_gray_to_rgb(&(png_ptr->row_info), png_ptr->row_buf + 1);
-#endif
-
-#if defined(PNG_READ_FILLER_SUPPORTED)
- if (png_ptr->transformations & PNG_FILLER)
- png_do_read_filler(&(png_ptr->row_info), png_ptr->row_buf + 1,
- (png_uint_32)png_ptr->filler, png_ptr->flags);
-#endif
-
-#if defined(PNG_READ_INVERT_ALPHA_SUPPORTED)
- if (png_ptr->transformations & PNG_INVERT_ALPHA)
- png_do_read_invert_alpha(&(png_ptr->row_info), png_ptr->row_buf + 1);
-#endif
-
-#if defined(PNG_READ_SWAP_ALPHA_SUPPORTED)
- if (png_ptr->transformations & PNG_SWAP_ALPHA)
- png_do_read_swap_alpha(&(png_ptr->row_info), png_ptr->row_buf + 1);
-#endif
-
-#if defined(PNG_READ_SWAP_SUPPORTED)
- if (png_ptr->transformations & PNG_SWAP_BYTES)
- png_do_swap(&(png_ptr->row_info), png_ptr->row_buf + 1);
-#endif
-
-#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED)
- if (png_ptr->transformations & PNG_USER_TRANSFORM)
- {
- if (png_ptr->read_user_transform_fn != NULL)
- (*(png_ptr->read_user_transform_fn)) /* User read transform function */
- (png_ptr, /* png_ptr */
- &(png_ptr->row_info), /* row_info: */
- /* png_uint_32 width; width of row */
- /* png_uint_32 rowbytes; number of bytes in row */
- /* png_byte color_type; color type of pixels */
- /* png_byte bit_depth; bit depth of samples */
- /* png_byte channels; number of channels (1-4) */
- /* png_byte pixel_depth; bits per pixel (depth*channels) */
- png_ptr->row_buf + 1); /* start of pixel data for row */
-#if defined(PNG_USER_TRANSFORM_PTR_SUPPORTED)
- if (png_ptr->user_transform_depth)
- png_ptr->row_info.bit_depth = png_ptr->user_transform_depth;
- if (png_ptr->user_transform_channels)
- png_ptr->row_info.channels = png_ptr->user_transform_channels;
-#endif
- png_ptr->row_info.pixel_depth = (png_byte)(png_ptr->row_info.bit_depth *
- png_ptr->row_info.channels);
- png_ptr->row_info.rowbytes = PNG_ROWBYTES(png_ptr->row_info.pixel_depth,
- png_ptr->row_info.width);
- }
-#endif
-
-}
-
-#if defined(PNG_READ_PACK_SUPPORTED)
-/* Unpack pixels of 1, 2, or 4 bits per pixel into 1 byte per pixel,
- * without changing the actual values. Thus, if you had a row with
- * a bit depth of 1, you would end up with bytes that only contained
- * the numbers 0 or 1. If you would rather they contain 0 and 255, use
- * png_do_shift() after this.
- */
-void /* PRIVATE */
-png_do_unpack(png_row_infop row_info, png_bytep row)
-{
- png_debug(1, "in png_do_unpack");
-#if defined(PNG_USELESS_TESTS_SUPPORTED)
- if (row != NULL && row_info != NULL && row_info->bit_depth < 8)
-#else
- if (row_info->bit_depth < 8)
-#endif
- {
- png_uint_32 i;
- png_uint_32 row_width=row_info->width;
-
- switch (row_info->bit_depth)
- {
- case 1:
- {
- png_bytep sp = row + (png_size_t)((row_width - 1) >> 3);
- png_bytep dp = row + (png_size_t)row_width - 1;
- png_uint_32 shift = 7 - (int)((row_width + 7) & 0x07);
- for (i = 0; i < row_width; i++)
- {
- *dp = (png_byte)((*sp >> shift) & 0x01);
- if (shift == 7)
- {
- shift = 0;
- sp--;
- }
- else
- shift++;
-
- dp--;
- }
- break;
- }
-
- case 2:
- {
-
- png_bytep sp = row + (png_size_t)((row_width - 1) >> 2);
- png_bytep dp = row + (png_size_t)row_width - 1;
- png_uint_32 shift = (int)((3 - ((row_width + 3) & 0x03)) << 1);
- for (i = 0; i < row_width; i++)
- {
- *dp = (png_byte)((*sp >> shift) & 0x03);
- if (shift == 6)
- {
- shift = 0;
- sp--;
- }
- else
- shift += 2;
-
- dp--;
- }
- break;
- }
-
- case 4:
- {
- png_bytep sp = row + (png_size_t)((row_width - 1) >> 1);
- png_bytep dp = row + (png_size_t)row_width - 1;
- png_uint_32 shift = (int)((1 - ((row_width + 1) & 0x01)) << 2);
- for (i = 0; i < row_width; i++)
- {
- *dp = (png_byte)((*sp >> shift) & 0x0f);
- if (shift == 4)
- {
- shift = 0;
- sp--;
- }
- else
- shift = 4;
-
- dp--;
- }
- break;
- }
- }
- row_info->bit_depth = 8;
- row_info->pixel_depth = (png_byte)(8 * row_info->channels);
- row_info->rowbytes = row_width * row_info->channels;
- }
-}
-#endif
-
-#if defined(PNG_READ_SHIFT_SUPPORTED)
-/* Reverse the effects of png_do_shift. This routine merely shifts the
- * pixels back to their significant bits values. Thus, if you have
- * a row of bit depth 8, but only 5 are significant, this will shift
- * the values back to 0 through 31.
- */
-void /* PRIVATE */
-png_do_unshift(png_row_infop row_info, png_bytep row, png_color_8p sig_bits)
-{
- png_debug(1, "in png_do_unshift");
- if (
-#if defined(PNG_USELESS_TESTS_SUPPORTED)
- row != NULL && row_info != NULL && sig_bits != NULL &&
-#endif
- row_info->color_type != PNG_COLOR_TYPE_PALETTE)
- {
- int shift[4];
- int channels = 0;
- int c;
- png_uint_16 value = 0;
- png_uint_32 row_width = row_info->width;
-
- if (row_info->color_type & PNG_COLOR_MASK_COLOR)
- {
- shift[channels++] = row_info->bit_depth - sig_bits->red;
- shift[channels++] = row_info->bit_depth - sig_bits->green;
- shift[channels++] = row_info->bit_depth - sig_bits->blue;
- }
- else
- {
- shift[channels++] = row_info->bit_depth - sig_bits->gray;
- }
- if (row_info->color_type & PNG_COLOR_MASK_ALPHA)
- {
- shift[channels++] = row_info->bit_depth - sig_bits->alpha;
- }
-
- for (c = 0; c < channels; c++)
- {
- if (shift[c] <= 0)
- shift[c] = 0;
- else
- value = 1;
- }
-
- if (!value)
- return;
-
- switch (row_info->bit_depth)
- {
- case 2:
- {
- png_bytep bp;
- png_uint_32 i;
- png_uint_32 istop = row_info->rowbytes;
-
- for (bp = row, i = 0; i < istop; i++)
- {
- *bp >>= 1;
- *bp++ &= 0x55;
- }
- break;
- }
-
- case 4:
- {
- png_bytep bp = row;
- png_uint_32 i;
- png_uint_32 istop = row_info->rowbytes;
- png_byte mask = (png_byte)((((int)0xf0 >> shift[0]) & (int)0xf0) |
- (png_byte)((int)0xf >> shift[0]));
-
- for (i = 0; i < istop; i++)
- {
- *bp >>= shift[0];
- *bp++ &= mask;
- }
- break;
- }
-
- case 8:
- {
- png_bytep bp = row;
- png_uint_32 i;
- png_uint_32 istop = row_width * channels;
-
- for (i = 0; i < istop; i++)
- {
- *bp++ >>= shift[i%channels];
- }
- break;
- }
-
- case 16:
- {
- png_bytep bp = row;
- png_uint_32 i;
- png_uint_32 istop = channels * row_width;
-
- for (i = 0; i < istop; i++)
- {
- value = (png_uint_16)((*bp << 8) + *(bp + 1));
- value >>= shift[i%channels];
- *bp++ = (png_byte)(value >> 8);
- *bp++ = (png_byte)(value & 0xff);
- }
- break;
- }
- }
- }
-}
-#endif
-
-#if defined(PNG_READ_16_TO_8_SUPPORTED)
-/* Chop rows of bit depth 16 down to 8 */
-void /* PRIVATE */
-png_do_chop(png_row_infop row_info, png_bytep row)
-{
- png_debug(1, "in png_do_chop");
-#if defined(PNG_USELESS_TESTS_SUPPORTED)
- if (row != NULL && row_info != NULL && row_info->bit_depth == 16)
-#else
- if (row_info->bit_depth == 16)
-#endif
- {
- png_bytep sp = row;
- png_bytep dp = row;
- png_uint_32 i;
- png_uint_32 istop = row_info->width * row_info->channels;
-
- for (i = 0; i<istop; i++, sp += 2, dp++)
- {
-#if defined(PNG_READ_16_TO_8_ACCURATE_SCALE_SUPPORTED)
- /* This does a more accurate scaling of the 16-bit color
- * value, rather than a simple low-byte truncation.
- *
- * What the ideal calculation should be:
- * *dp = (((((png_uint_32)(*sp) << 8) |
- * (png_uint_32)(*(sp + 1))) * 255 + 127)
- * / (png_uint_32)65535L;
- *
- * GRR: no, I think this is what it really should be:
- * *dp = (((((png_uint_32)(*sp) << 8) |
- * (png_uint_32)(*(sp + 1))) + 128L)
- * / (png_uint_32)257L;
- *
- * GRR: here's the exact calculation with shifts:
- * temp = (((png_uint_32)(*sp) << 8) |
- * (png_uint_32)(*(sp + 1))) + 128L;
- * *dp = (temp - (temp >> 8)) >> 8;
- *
- * Approximate calculation with shift/add instead of multiply/divide:
- * *dp = ((((png_uint_32)(*sp) << 8) |
- * (png_uint_32)((int)(*(sp + 1)) - *sp)) + 128) >> 8;
- *
- * What we actually do to avoid extra shifting and conversion:
- */
-
- *dp = *sp + ((((int)(*(sp + 1)) - *sp) > 128) ? 1 : 0);
-#else
- /* Simply discard the low order byte */
- *dp = *sp;
-#endif
- }
- row_info->bit_depth = 8;
- row_info->pixel_depth = (png_byte)(8 * row_info->channels);
- row_info->rowbytes = row_info->width * row_info->channels;
- }
-}
-#endif
-
-#if defined(PNG_READ_SWAP_ALPHA_SUPPORTED)
-void /* PRIVATE */
-png_do_read_swap_alpha(png_row_infop row_info, png_bytep row)
-{
- png_debug(1, "in png_do_read_swap_alpha");
-#if defined(PNG_USELESS_TESTS_SUPPORTED)
- if (row != NULL && row_info != NULL)
-#endif
- {
- png_uint_32 row_width = row_info->width;
- if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
- {
- /* This converts from RGBA to ARGB */
- if (row_info->bit_depth == 8)
- {
- png_bytep sp = row + row_info->rowbytes;
- png_bytep dp = sp;
- png_byte save;
- png_uint_32 i;
-
- for (i = 0; i < row_width; i++)
- {
- save = *(--sp);
- *(--dp) = *(--sp);
- *(--dp) = *(--sp);
- *(--dp) = *(--sp);
- *(--dp) = save;
- }
- }
- /* This converts from RRGGBBAA to AARRGGBB */
- else
- {
- png_bytep sp = row + row_info->rowbytes;
- png_bytep dp = sp;
- png_byte save[2];
- png_uint_32 i;
-
- for (i = 0; i < row_width; i++)
- {
- save[0] = *(--sp);
- save[1] = *(--sp);
- *(--dp) = *(--sp);
- *(--dp) = *(--sp);
- *(--dp) = *(--sp);
- *(--dp) = *(--sp);
- *(--dp) = *(--sp);
- *(--dp) = *(--sp);
- *(--dp) = save[0];
- *(--dp) = save[1];
- }
- }
- }
- else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
- {
- /* This converts from GA to AG */
- if (row_info->bit_depth == 8)
- {
- png_bytep sp = row + row_info->rowbytes;
- png_bytep dp = sp;
- png_byte save;
- png_uint_32 i;
-
- for (i = 0; i < row_width; i++)
- {
- save = *(--sp);
- *(--dp) = *(--sp);
- *(--dp) = save;
- }
- }
- /* This converts from GGAA to AAGG */
- else
- {
- png_bytep sp = row + row_info->rowbytes;
- png_bytep dp = sp;
- png_byte save[2];
- png_uint_32 i;
-
- for (i = 0; i < row_width; i++)
- {
- save[0] = *(--sp);
- save[1] = *(--sp);
- *(--dp) = *(--sp);
- *(--dp) = *(--sp);
- *(--dp) = save[0];
- *(--dp) = save[1];
- }
- }
- }
- }
-}
-#endif
-
-#if defined(PNG_READ_INVERT_ALPHA_SUPPORTED)
-void /* PRIVATE */
-png_do_read_invert_alpha(png_row_infop row_info, png_bytep row)
-{
- png_debug(1, "in png_do_read_invert_alpha");
-#if defined(PNG_USELESS_TESTS_SUPPORTED)
- if (row != NULL && row_info != NULL)
-#endif
- {
- png_uint_32 row_width = row_info->width;
- if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
- {
- /* This inverts the alpha channel in RGBA */
- if (row_info->bit_depth == 8)
- {
- png_bytep sp = row + row_info->rowbytes;
- png_bytep dp = sp;
- png_uint_32 i;
-
- for (i = 0; i < row_width; i++)
- {
- *(--dp) = (png_byte)(255 - *(--sp));
-
-/* This does nothing:
- *(--dp) = *(--sp);
- *(--dp) = *(--sp);
- *(--dp) = *(--sp);
- We can replace it with:
-*/
- sp-=3;
- dp=sp;
- }
- }
- /* This inverts the alpha channel in RRGGBBAA */
- else
- {
- png_bytep sp = row + row_info->rowbytes;
- png_bytep dp = sp;
- png_uint_32 i;
-
- for (i = 0; i < row_width; i++)
- {
- *(--dp) = (png_byte)(255 - *(--sp));
- *(--dp) = (png_byte)(255 - *(--sp));
-
-/* This does nothing:
- *(--dp) = *(--sp);
- *(--dp) = *(--sp);
- *(--dp) = *(--sp);
- *(--dp) = *(--sp);
- *(--dp) = *(--sp);
- *(--dp) = *(--sp);
- We can replace it with:
-*/
- sp-=6;
- dp=sp;
- }
- }
- }
- else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
- {
- /* This inverts the alpha channel in GA */
- if (row_info->bit_depth == 8)
- {
- png_bytep sp = row + row_info->rowbytes;
- png_bytep dp = sp;
- png_uint_32 i;
-
- for (i = 0; i < row_width; i++)
- {
- *(--dp) = (png_byte)(255 - *(--sp));
- *(--dp) = *(--sp);
- }
- }
- /* This inverts the alpha channel in GGAA */
- else
- {
- png_bytep sp = row + row_info->rowbytes;
- png_bytep dp = sp;
- png_uint_32 i;
-
- for (i = 0; i < row_width; i++)
- {
- *(--dp) = (png_byte)(255 - *(--sp));
- *(--dp) = (png_byte)(255 - *(--sp));
-/*
- *(--dp) = *(--sp);
- *(--dp) = *(--sp);
-*/
- sp-=2;
- dp=sp;
- }
- }
- }
- }
-}
-#endif
-
-#if defined(PNG_READ_FILLER_SUPPORTED)
-/* Add filler channel if we have RGB color */
-void /* PRIVATE */
-png_do_read_filler(png_row_infop row_info, png_bytep row,
- png_uint_32 filler, png_uint_32 flags)
-{
- png_uint_32 i;
- png_uint_32 row_width = row_info->width;
-
- png_byte hi_filler = (png_byte)((filler>>8) & 0xff);
- png_byte lo_filler = (png_byte)(filler & 0xff);
-
- png_debug(1, "in png_do_read_filler");
- if (
-#if defined(PNG_USELESS_TESTS_SUPPORTED)
- row != NULL && row_info != NULL &&
-#endif
- row_info->color_type == PNG_COLOR_TYPE_GRAY)
- {
- if (row_info->bit_depth == 8)
- {
- /* This changes the data from G to GX */
- if (flags & PNG_FLAG_FILLER_AFTER)
- {
- png_bytep sp = row + (png_size_t)row_width;
- png_bytep dp = sp + (png_size_t)row_width;
- for (i = 1; i < row_width; i++)
- {
- *(--dp) = lo_filler;
- *(--dp) = *(--sp);
- }
- *(--dp) = lo_filler;
- row_info->channels = 2;
- row_info->pixel_depth = 16;
- row_info->rowbytes = row_width * 2;
- }
- /* This changes the data from G to XG */
- else
- {
- png_bytep sp = row + (png_size_t)row_width;
- png_bytep dp = sp + (png_size_t)row_width;
- for (i = 0; i < row_width; i++)
- {
- *(--dp) = *(--sp);
- *(--dp) = lo_filler;
- }
- row_info->channels = 2;
- row_info->pixel_depth = 16;
- row_info->rowbytes = row_width * 2;
- }
- }
- else if (row_info->bit_depth == 16)
- {
- /* This changes the data from GG to GGXX */
- if (flags & PNG_FLAG_FILLER_AFTER)
- {
- png_bytep sp = row + (png_size_t)row_width * 2;
- png_bytep dp = sp + (png_size_t)row_width * 2;
- for (i = 1; i < row_width; i++)
- {
- *(--dp) = hi_filler;
- *(--dp) = lo_filler;
- *(--dp) = *(--sp);
- *(--dp) = *(--sp);
- }
- *(--dp) = hi_filler;
- *(--dp) = lo_filler;
- row_info->channels = 2;
- row_info->pixel_depth = 32;
- row_info->rowbytes = row_width * 4;
- }
- /* This changes the data from GG to XXGG */
- else
- {
- png_bytep sp = row + (png_size_t)row_width * 2;
- png_bytep dp = sp + (png_size_t)row_width * 2;
- for (i = 0; i < row_width; i++)
- {
- *(--dp) = *(--sp);
- *(--dp) = *(--sp);
- *(--dp) = hi_filler;
- *(--dp) = lo_filler;
- }
- row_info->channels = 2;
- row_info->pixel_depth = 32;
- row_info->rowbytes = row_width * 4;
- }
- }
- } /* COLOR_TYPE == GRAY */
- else if (row_info->color_type == PNG_COLOR_TYPE_RGB)
- {
- if (row_info->bit_depth == 8)
- {
- /* This changes the data from RGB to RGBX */
- if (flags & PNG_FLAG_FILLER_AFTER)
- {
- png_bytep sp = row + (png_size_t)row_width * 3;
- png_bytep dp = sp + (png_size_t)row_width;
- for (i = 1; i < row_width; i++)
- {
- *(--dp) = lo_filler;
- *(--dp) = *(--sp);
- *(--dp) = *(--sp);
- *(--dp) = *(--sp);
- }
- *(--dp) = lo_filler;
- row_info->channels = 4;
- row_info->pixel_depth = 32;
- row_info->rowbytes = row_width * 4;
- }
- /* This changes the data from RGB to XRGB */
- else
- {
- png_bytep sp = row + (png_size_t)row_width * 3;
- png_bytep dp = sp + (png_size_t)row_width;
- for (i = 0; i < row_width; i++)
- {
- *(--dp) = *(--sp);
- *(--dp) = *(--sp);
- *(--dp) = *(--sp);
- *(--dp) = lo_filler;
- }
- row_info->channels = 4;
- row_info->pixel_depth = 32;
- row_info->rowbytes = row_width * 4;
- }
- }
- else if (row_info->bit_depth == 16)
- {
- /* This changes the data from RRGGBB to RRGGBBXX */
- if (flags & PNG_FLAG_FILLER_AFTER)
- {
- png_bytep sp = row + (png_size_t)row_width * 6;
- png_bytep dp = sp + (png_size_t)row_width * 2;
- for (i = 1; i < row_width; i++)
- {
- *(--dp) = hi_filler;
- *(--dp) = lo_filler;
- *(--dp) = *(--sp);
- *(--dp) = *(--sp);
- *(--dp) = *(--sp);
- *(--dp) = *(--sp);
- *(--dp) = *(--sp);
- *(--dp) = *(--sp);
- }
- *(--dp) = hi_filler;
- *(--dp) = lo_filler;
- row_info->channels = 4;
- row_info->pixel_depth = 64;
- row_info->rowbytes = row_width * 8;
- }
- /* This changes the data from RRGGBB to XXRRGGBB */
- else
- {
- png_bytep sp = row + (png_size_t)row_width * 6;
- png_bytep dp = sp + (png_size_t)row_width * 2;
- for (i = 0; i < row_width; i++)
- {
- *(--dp) = *(--sp);
- *(--dp) = *(--sp);
- *(--dp) = *(--sp);
- *(--dp) = *(--sp);
- *(--dp) = *(--sp);
- *(--dp) = *(--sp);
- *(--dp) = hi_filler;
- *(--dp) = lo_filler;
- }
- row_info->channels = 4;
- row_info->pixel_depth = 64;
- row_info->rowbytes = row_width * 8;
- }
- }
- } /* COLOR_TYPE == RGB */
-}
-#endif
-
-#if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED)
-/* Expand grayscale files to RGB, with or without alpha */
-void /* PRIVATE */
-png_do_gray_to_rgb(png_row_infop row_info, png_bytep row)
-{
- png_uint_32 i;
- png_uint_32 row_width = row_info->width;
-
- png_debug(1, "in png_do_gray_to_rgb");
- if (row_info->bit_depth >= 8 &&
-#if defined(PNG_USELESS_TESTS_SUPPORTED)
- row != NULL && row_info != NULL &&
-#endif
- !(row_info->color_type & PNG_COLOR_MASK_COLOR))
- {
- if (row_info->color_type == PNG_COLOR_TYPE_GRAY)
- {
- if (row_info->bit_depth == 8)
- {
- png_bytep sp = row + (png_size_t)row_width - 1;
- png_bytep dp = sp + (png_size_t)row_width * 2;
- for (i = 0; i < row_width; i++)
- {
- *(dp--) = *sp;
- *(dp--) = *sp;
- *(dp--) = *(sp--);
- }
- }
- else
- {
- png_bytep sp = row + (png_size_t)row_width * 2 - 1;
- png_bytep dp = sp + (png_size_t)row_width * 4;
- for (i = 0; i < row_width; i++)
- {
- *(dp--) = *sp;
- *(dp--) = *(sp - 1);
- *(dp--) = *sp;
- *(dp--) = *(sp - 1);
- *(dp--) = *(sp--);
- *(dp--) = *(sp--);
- }
- }
- }
- else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
- {
- if (row_info->bit_depth == 8)
- {
- png_bytep sp = row + (png_size_t)row_width * 2 - 1;
- png_bytep dp = sp + (png_size_t)row_width * 2;
- for (i = 0; i < row_width; i++)
- {
- *(dp--) = *(sp--);
- *(dp--) = *sp;
- *(dp--) = *sp;
- *(dp--) = *(sp--);
- }
- }
- else
- {
- png_bytep sp = row + (png_size_t)row_width * 4 - 1;
- png_bytep dp = sp + (png_size_t)row_width * 4;
- for (i = 0; i < row_width; i++)
- {
- *(dp--) = *(sp--);
- *(dp--) = *(sp--);
- *(dp--) = *sp;
- *(dp--) = *(sp - 1);
- *(dp--) = *sp;
- *(dp--) = *(sp - 1);
- *(dp--) = *(sp--);
- *(dp--) = *(sp--);
- }
- }
- }
- row_info->channels += (png_byte)2;
- row_info->color_type |= PNG_COLOR_MASK_COLOR;
- row_info->pixel_depth = (png_byte)(row_info->channels *
- row_info->bit_depth);
- row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width);
- }
-}
-#endif
-
-#if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
-/* Reduce RGB files to grayscale, with or without alpha
- * using the equation given in Poynton's ColorFAQ at
- * <http://www.inforamp.net/~poynton/> (THIS LINK IS DEAD June 2008)
- * New link:
- * <http://www.poynton.com/notes/colour_and_gamma/>
- * Charles Poynton poynton at poynton.com
- *
- * Y = 0.212671 * R + 0.715160 * G + 0.072169 * B
- *
- * We approximate this with
- *
- * Y = 0.21268 * R + 0.7151 * G + 0.07217 * B
- *
- * which can be expressed with integers as
- *
- * Y = (6969 * R + 23434 * G + 2365 * B)/32768
- *
- * The calculation is to be done in a linear colorspace.
- *
- * Other integer coefficents can be used via png_set_rgb_to_gray().
- */
-int /* PRIVATE */
-png_do_rgb_to_gray(png_structp png_ptr, png_row_infop row_info, png_bytep row)
-
-{
- png_uint_32 i;
-
- png_uint_32 row_width = row_info->width;
- int rgb_error = 0;
-
- png_debug(1, "in png_do_rgb_to_gray");
- if (
-#if defined(PNG_USELESS_TESTS_SUPPORTED)
- row != NULL && row_info != NULL &&
-#endif
- (row_info->color_type & PNG_COLOR_MASK_COLOR))
- {
- png_uint_32 rc = png_ptr->rgb_to_gray_red_coeff;
- png_uint_32 gc = png_ptr->rgb_to_gray_green_coeff;
- png_uint_32 bc = png_ptr->rgb_to_gray_blue_coeff;
-
- if (row_info->color_type == PNG_COLOR_TYPE_RGB)
- {
- if (row_info->bit_depth == 8)
- {
-#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
- if (png_ptr->gamma_from_1 != NULL && png_ptr->gamma_to_1 != NULL)
- {
- png_bytep sp = row;
- png_bytep dp = row;
-
- for (i = 0; i < row_width; i++)
- {
- png_byte red = png_ptr->gamma_to_1[*(sp++)];
- png_byte green = png_ptr->gamma_to_1[*(sp++)];
- png_byte blue = png_ptr->gamma_to_1[*(sp++)];
- if (red != green || red != blue)
- {
- rgb_error |= 1;
- *(dp++) = png_ptr->gamma_from_1[
- (rc*red + gc*green + bc*blue)>>15];
- }
- else
- *(dp++) = *(sp - 1);
- }
- }
- else
-#endif
- {
- png_bytep sp = row;
- png_bytep dp = row;
- for (i = 0; i < row_width; i++)
- {
- png_byte red = *(sp++);
- png_byte green = *(sp++);
- png_byte blue = *(sp++);
- if (red != green || red != blue)
- {
- rgb_error |= 1;
- *(dp++) = (png_byte)((rc*red + gc*green + bc*blue)>>15);
- }
- else
- *(dp++) = *(sp - 1);
- }
- }
- }
-
- else /* RGB bit_depth == 16 */
- {
-#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
- if (png_ptr->gamma_16_to_1 != NULL &&
- png_ptr->gamma_16_from_1 != NULL)
- {
- png_bytep sp = row;
- png_bytep dp = row;
- for (i = 0; i < row_width; i++)
- {
- png_uint_16 red, green, blue, w;
-
- red = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2;
- green = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2;
- blue = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2;
-
- if (red == green && red == blue)
- w = red;
- else
- {
- png_uint_16 red_1 = png_ptr->gamma_16_to_1[(red&0xff) >>
- png_ptr->gamma_shift][red>>8];
- png_uint_16 green_1 = png_ptr->gamma_16_to_1[(green&0xff) >>
- png_ptr->gamma_shift][green>>8];
- png_uint_16 blue_1 = png_ptr->gamma_16_to_1[(blue&0xff) >>
- png_ptr->gamma_shift][blue>>8];
- png_uint_16 gray16 = (png_uint_16)((rc*red_1 + gc*green_1
- + bc*blue_1)>>15);
- w = png_ptr->gamma_16_from_1[(gray16&0xff) >>
- png_ptr->gamma_shift][gray16 >> 8];
- rgb_error |= 1;
- }
-
- *(dp++) = (png_byte)((w>>8) & 0xff);
- *(dp++) = (png_byte)(w & 0xff);
- }
- }
- else
-#endif
- {
- png_bytep sp = row;
- png_bytep dp = row;
- for (i = 0; i < row_width; i++)
- {
- png_uint_16 red, green, blue, gray16;
-
- red = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2;
- green = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2;
- blue = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2;
-
- if (red != green || red != blue)
- rgb_error |= 1;
- gray16 = (png_uint_16)((rc*red + gc*green + bc*blue)>>15);
- *(dp++) = (png_byte)((gray16>>8) & 0xff);
- *(dp++) = (png_byte)(gray16 & 0xff);
- }
- }
- }
- }
- if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
- {
- if (row_info->bit_depth == 8)
- {
-#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
- if (png_ptr->gamma_from_1 != NULL && png_ptr->gamma_to_1 != NULL)
- {
- png_bytep sp = row;
- png_bytep dp = row;
- for (i = 0; i < row_width; i++)
- {
- png_byte red = png_ptr->gamma_to_1[*(sp++)];
- png_byte green = png_ptr->gamma_to_1[*(sp++)];
- png_byte blue = png_ptr->gamma_to_1[*(sp++)];
- if (red != green || red != blue)
- rgb_error |= 1;
- *(dp++) = png_ptr->gamma_from_1
- [(rc*red + gc*green + bc*blue)>>15];
- *(dp++) = *(sp++); /* alpha */
- }
- }
- else
-#endif
- {
- png_bytep sp = row;
- png_bytep dp = row;
- for (i = 0; i < row_width; i++)
- {
- png_byte red = *(sp++);
- png_byte green = *(sp++);
- png_byte blue = *(sp++);
- if (red != green || red != blue)
- rgb_error |= 1;
- *(dp++) = (png_byte)((rc*red + gc*green + bc*blue)>>15);
- *(dp++) = *(sp++); /* alpha */
- }
- }
- }
- else /* RGBA bit_depth == 16 */
- {
-#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
- if (png_ptr->gamma_16_to_1 != NULL &&
- png_ptr->gamma_16_from_1 != NULL)
- {
- png_bytep sp = row;
- png_bytep dp = row;
- for (i = 0; i < row_width; i++)
- {
- png_uint_16 red, green, blue, w;
-
- red = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2;
- green = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2;
- blue = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2;
-
- if (red == green && red == blue)
- w = red;
- else
- {
- png_uint_16 red_1 = png_ptr->gamma_16_to_1[(red&0xff) >>
- png_ptr->gamma_shift][red>>8];
- png_uint_16 green_1 = png_ptr->gamma_16_to_1[(green&0xff) >>
- png_ptr->gamma_shift][green>>8];
- png_uint_16 blue_1 = png_ptr->gamma_16_to_1[(blue&0xff) >>
- png_ptr->gamma_shift][blue>>8];
- png_uint_16 gray16 = (png_uint_16)((rc * red_1
- + gc * green_1 + bc * blue_1)>>15);
- w = png_ptr->gamma_16_from_1[(gray16&0xff) >>
- png_ptr->gamma_shift][gray16 >> 8];
- rgb_error |= 1;
- }
-
- *(dp++) = (png_byte)((w>>8) & 0xff);
- *(dp++) = (png_byte)(w & 0xff);
- *(dp++) = *(sp++); /* alpha */
- *(dp++) = *(sp++);
- }
- }
- else
-#endif
- {
- png_bytep sp = row;
- png_bytep dp = row;
- for (i = 0; i < row_width; i++)
- {
- png_uint_16 red, green, blue, gray16;
- red = (png_uint_16)((*(sp)<<8) | *(sp+1)); sp+=2;
- green = (png_uint_16)((*(sp)<<8) | *(sp+1)); sp+=2;
- blue = (png_uint_16)((*(sp)<<8) | *(sp+1)); sp+=2;
- if (red != green || red != blue)
- rgb_error |= 1;
- gray16 = (png_uint_16)((rc*red + gc*green + bc*blue)>>15);
- *(dp++) = (png_byte)((gray16>>8) & 0xff);
- *(dp++) = (png_byte)(gray16 & 0xff);
- *(dp++) = *(sp++); /* alpha */
- *(dp++) = *(sp++);
- }
- }
- }
- }
- row_info->channels -= (png_byte)2;
- row_info->color_type &= ~PNG_COLOR_MASK_COLOR;
- row_info->pixel_depth = (png_byte)(row_info->channels *
- row_info->bit_depth);
- row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width);
- }
- return rgb_error;
-}
-#endif
-
-/* Build a grayscale palette. Palette is assumed to be 1 << bit_depth
- * large of png_color. This lets grayscale images be treated as
- * paletted. Most useful for gamma correction and simplification
- * of code.
- */
-void PNGAPI
-png_build_grayscale_palette(int bit_depth, png_colorp palette)
-{
- int num_palette;
- int color_inc;
- int i;
- int v;
-
- png_debug(1, "in png_do_build_grayscale_palette");
- if (palette == NULL)
- return;
-
- switch (bit_depth)
- {
- case 1:
- num_palette = 2;
- color_inc = 0xff;
- break;
-
- case 2:
- num_palette = 4;
- color_inc = 0x55;
- break;
-
- case 4:
- num_palette = 16;
- color_inc = 0x11;
- break;
-
- case 8:
- num_palette = 256;
- color_inc = 1;
- break;
-
- default:
- num_palette = 0;
- color_inc = 0;
- break;
- }
-
- for (i = 0, v = 0; i < num_palette; i++, v += color_inc)
- {
- palette[i].red = (png_byte)v;
- palette[i].green = (png_byte)v;
- palette[i].blue = (png_byte)v;
- }
-}
-
-/* This function is currently unused. Do we really need it? */
-#if defined(PNG_READ_DITHER_SUPPORTED) && defined(PNG_CORRECT_PALETTE_SUPPORTED)
-void /* PRIVATE */
-png_correct_palette(png_structp png_ptr, png_colorp palette,
- int num_palette)
-{
- png_debug(1, "in png_correct_palette");
-#if defined(PNG_READ_BACKGROUND_SUPPORTED) && \
- defined(PNG_READ_GAMMA_SUPPORTED) && defined(PNG_FLOATING_POINT_SUPPORTED)
- if (png_ptr->transformations & (PNG_GAMMA | PNG_BACKGROUND))
- {
- png_color back, back_1;
-
- if (png_ptr->background_gamma_type == PNG_BACKGROUND_GAMMA_FILE)
- {
- back.red = png_ptr->gamma_table[png_ptr->background.red];
- back.green = png_ptr->gamma_table[png_ptr->background.green];
- back.blue = png_ptr->gamma_table[png_ptr->background.blue];
-
- back_1.red = png_ptr->gamma_to_1[png_ptr->background.red];
- back_1.green = png_ptr->gamma_to_1[png_ptr->background.green];
- back_1.blue = png_ptr->gamma_to_1[png_ptr->background.blue];
- }
- else
- {
- double g;
-
- g = 1.0 / (png_ptr->background_gamma * png_ptr->screen_gamma);
-
- if (png_ptr->background_gamma_type == PNG_BACKGROUND_GAMMA_SCREEN ||
- fabs(g - 1.0) < PNG_GAMMA_THRESHOLD)
- {
- back.red = png_ptr->background.red;
- back.green = png_ptr->background.green;
- back.blue = png_ptr->background.blue;
- }
- else
- {
- back.red =
- (png_byte)(pow((double)png_ptr->background.red/255, g) *
- 255.0 + 0.5);
- back.green =
- (png_byte)(pow((double)png_ptr->background.green/255, g) *
- 255.0 + 0.5);
- back.blue =
- (png_byte)(pow((double)png_ptr->background.blue/255, g) *
- 255.0 + 0.5);
- }
-
- g = 1.0 / png_ptr->background_gamma;
-
- back_1.red =
- (png_byte)(pow((double)png_ptr->background.red/255, g) *
- 255.0 + 0.5);
- back_1.green =
- (png_byte)(pow((double)png_ptr->background.green/255, g) *
- 255.0 + 0.5);
- back_1.blue =
- (png_byte)(pow((double)png_ptr->background.blue/255, g) *
- 255.0 + 0.5);
- }
-
- if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
- {
- png_uint_32 i;
-
- for (i = 0; i < (png_uint_32)num_palette; i++)
- {
- if (i < png_ptr->num_trans && png_ptr->trans[i] == 0)
- {
- palette[i] = back;
- }
- else if (i < png_ptr->num_trans && png_ptr->trans[i] != 0xff)
- {
- png_byte v, w;
-
- v = png_ptr->gamma_to_1[png_ptr->palette[i].red];
- png_composite(w, v, png_ptr->trans[i], back_1.red);
- palette[i].red = png_ptr->gamma_from_1[w];
-
- v = png_ptr->gamma_to_1[png_ptr->palette[i].green];
- png_composite(w, v, png_ptr->trans[i], back_1.green);
- palette[i].green = png_ptr->gamma_from_1[w];
-
- v = png_ptr->gamma_to_1[png_ptr->palette[i].blue];
- png_composite(w, v, png_ptr->trans[i], back_1.blue);
- palette[i].blue = png_ptr->gamma_from_1[w];
- }
- else
- {
- palette[i].red = png_ptr->gamma_table[palette[i].red];
- palette[i].green = png_ptr->gamma_table[palette[i].green];
- palette[i].blue = png_ptr->gamma_table[palette[i].blue];
- }
- }
- }
- else
- {
- int i;
-
- for (i = 0; i < num_palette; i++)
- {
- if (palette[i].red == (png_byte)png_ptr->trans_values.gray)
- {
- palette[i] = back;
- }
- else
- {
- palette[i].red = png_ptr->gamma_table[palette[i].red];
- palette[i].green = png_ptr->gamma_table[palette[i].green];
- palette[i].blue = png_ptr->gamma_table[palette[i].blue];
- }
- }
- }
- }
- else
-#endif
-#if defined(PNG_READ_GAMMA_SUPPORTED)
- if (png_ptr->transformations & PNG_GAMMA)
- {
- int i;
-
- for (i = 0; i < num_palette; i++)
- {
- palette[i].red = png_ptr->gamma_table[palette[i].red];
- palette[i].green = png_ptr->gamma_table[palette[i].green];
- palette[i].blue = png_ptr->gamma_table[palette[i].blue];
- }
- }
-#if defined(PNG_READ_BACKGROUND_SUPPORTED)
- else
-#endif
-#endif
-#if defined(PNG_READ_BACKGROUND_SUPPORTED)
- if (png_ptr->transformations & PNG_BACKGROUND)
- {
- if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
- {
- png_color back;
-
- back.red = (png_byte)png_ptr->background.red;
- back.green = (png_byte)png_ptr->background.green;
- back.blue = (png_byte)png_ptr->background.blue;
-
- for (i = 0; i < (int)png_ptr->num_trans; i++)
- {
- if (png_ptr->trans[i] == 0)
- {
- palette[i].red = back.red;
- palette[i].green = back.green;
- palette[i].blue = back.blue;
- }
- else if (png_ptr->trans[i] != 0xff)
- {
- png_composite(palette[i].red, png_ptr->palette[i].red,
- png_ptr->trans[i], back.red);
- png_composite(palette[i].green, png_ptr->palette[i].green,
- png_ptr->trans[i], back.green);
- png_composite(palette[i].blue, png_ptr->palette[i].blue,
- png_ptr->trans[i], back.blue);
- }
- }
- }
- else /* Assume grayscale palette (what else could it be?) */
- {
- int i;
-
- for (i = 0; i < num_palette; i++)
- {
- if (i == (png_byte)png_ptr->trans_values.gray)
- {
- palette[i].red = (png_byte)png_ptr->background.red;
- palette[i].green = (png_byte)png_ptr->background.green;
- palette[i].blue = (png_byte)png_ptr->background.blue;
- }
- }
- }
- }
-#endif
-}
-#endif
-
-#if defined(PNG_READ_BACKGROUND_SUPPORTED)
-/* Replace any alpha or transparency with the supplied background color.
- * "background" is already in the screen gamma, while "background_1" is
- * at a gamma of 1.0. Paletted files have already been taken care of.
- */
-void /* PRIVATE */
-png_do_background(png_row_infop row_info, png_bytep row,
- png_color_16p trans_values, png_color_16p background
-#if defined(PNG_READ_GAMMA_SUPPORTED)
- , png_color_16p background_1,
- png_bytep gamma_table, png_bytep gamma_from_1, png_bytep gamma_to_1,
- png_uint_16pp gamma_16, png_uint_16pp gamma_16_from_1,
- png_uint_16pp gamma_16_to_1, int gamma_shift
-#endif
- )
-{
- png_bytep sp, dp;
- png_uint_32 i;
- png_uint_32 row_width=row_info->width;
- int shift;
-
- png_debug(1, "in png_do_background");
- if (background != NULL &&
-#if defined(PNG_USELESS_TESTS_SUPPORTED)
- row != NULL && row_info != NULL &&
-#endif
- (!(row_info->color_type & PNG_COLOR_MASK_ALPHA) ||
- (row_info->color_type != PNG_COLOR_TYPE_PALETTE && trans_values)))
- {
- switch (row_info->color_type)
- {
- case PNG_COLOR_TYPE_GRAY:
- {
- switch (row_info->bit_depth)
- {
- case 1:
- {
- sp = row;
- shift = 7;
- for (i = 0; i < row_width; i++)
- {
- if ((png_uint_16)((*sp >> shift) & 0x01)
- == trans_values->gray)
- {
- *sp &= (png_byte)((0x7f7f >> (7 - shift)) & 0xff);
- *sp |= (png_byte)(background->gray << shift);
- }
- if (!shift)
- {
- shift = 7;
- sp++;
- }
- else
- shift--;
- }
- break;
- }
-
- case 2:
- {
-#if defined(PNG_READ_GAMMA_SUPPORTED)
- if (gamma_table != NULL)
- {
- sp = row;
- shift = 6;
- for (i = 0; i < row_width; i++)
- {
- if ((png_uint_16)((*sp >> shift) & 0x03)
- == trans_values->gray)
- {
- *sp &= (png_byte)((0x3f3f >> (6 - shift)) & 0xff);
- *sp |= (png_byte)(background->gray << shift);
- }
- else
- {
- png_byte p = (png_byte)((*sp >> shift) & 0x03);
- png_byte g = (png_byte)((gamma_table [p | (p << 2) |
- (p << 4) | (p << 6)] >> 6) & 0x03);
- *sp &= (png_byte)((0x3f3f >> (6 - shift)) & 0xff);
- *sp |= (png_byte)(g << shift);
- }
- if (!shift)
- {
- shift = 6;
- sp++;
- }
- else
- shift -= 2;
- }
- }
- else
-#endif
- {
- sp = row;
- shift = 6;
- for (i = 0; i < row_width; i++)
- {
- if ((png_uint_16)((*sp >> shift) & 0x03)
- == trans_values->gray)
- {
- *sp &= (png_byte)((0x3f3f >> (6 - shift)) & 0xff);
- *sp |= (png_byte)(background->gray << shift);
- }
- if (!shift)
- {
- shift = 6;
- sp++;
- }
- else
- shift -= 2;
- }
- }
- break;
- }
-
- case 4:
- {
-#if defined(PNG_READ_GAMMA_SUPPORTED)
- if (gamma_table != NULL)
- {
- sp = row;
- shift = 4;
- for (i = 0; i < row_width; i++)
- {
- if ((png_uint_16)((*sp >> shift) & 0x0f)
- == trans_values->gray)
- {
- *sp &= (png_byte)((0xf0f >> (4 - shift)) & 0xff);
- *sp |= (png_byte)(background->gray << shift);
- }
- else
- {
- png_byte p = (png_byte)((*sp >> shift) & 0x0f);
- png_byte g = (png_byte)((gamma_table[p |
- (p << 4)] >> 4) & 0x0f);
- *sp &= (png_byte)((0xf0f >> (4 - shift)) & 0xff);
- *sp |= (png_byte)(g << shift);
- }
- if (!shift)
- {
- shift = 4;
- sp++;
- }
- else
- shift -= 4;
- }
- }
- else
-#endif
- {
- sp = row;
- shift = 4;
- for (i = 0; i < row_width; i++)
- {
- if ((png_uint_16)((*sp >> shift) & 0x0f)
- == trans_values->gray)
- {
- *sp &= (png_byte)((0xf0f >> (4 - shift)) & 0xff);
- *sp |= (png_byte)(background->gray << shift);
- }
- if (!shift)
- {
- shift = 4;
- sp++;
- }
- else
- shift -= 4;
- }
- }
- break;
- }
-
- case 8:
- {
-#if defined(PNG_READ_GAMMA_SUPPORTED)
- if (gamma_table != NULL)
- {
- sp = row;
- for (i = 0; i < row_width; i++, sp++)
- {
- if (*sp == trans_values->gray)
- {
- *sp = (png_byte)background->gray;
- }
- else
- {
- *sp = gamma_table[*sp];
- }
- }
- }
- else
-#endif
- {
- sp = row;
- for (i = 0; i < row_width; i++, sp++)
- {
- if (*sp == trans_values->gray)
- {
- *sp = (png_byte)background->gray;
- }
- }
- }
- break;
- }
-
- case 16:
- {
-#if defined(PNG_READ_GAMMA_SUPPORTED)
- if (gamma_16 != NULL)
- {
- sp = row;
- for (i = 0; i < row_width; i++, sp += 2)
- {
- png_uint_16 v;
-
- v = (png_uint_16)(((*sp) << 8) + *(sp + 1));
- if (v == trans_values->gray)
- {
- /* Background is already in screen gamma */
- *sp = (png_byte)((background->gray >> 8) & 0xff);
- *(sp + 1) = (png_byte)(background->gray & 0xff);
- }
- else
- {
- v = gamma_16[*(sp + 1) >> gamma_shift][*sp];
- *sp = (png_byte)((v >> 8) & 0xff);
- *(sp + 1) = (png_byte)(v & 0xff);
- }
- }
- }
- else
-#endif
- {
- sp = row;
- for (i = 0; i < row_width; i++, sp += 2)
- {
- png_uint_16 v;
-
- v = (png_uint_16)(((*sp) << 8) + *(sp + 1));
- if (v == trans_values->gray)
- {
- *sp = (png_byte)((background->gray >> 8) & 0xff);
- *(sp + 1) = (png_byte)(background->gray & 0xff);
- }
- }
- }
- break;
- }
- }
- break;
- }
-
- case PNG_COLOR_TYPE_RGB:
- {
- if (row_info->bit_depth == 8)
- {
-#if defined(PNG_READ_GAMMA_SUPPORTED)
- if (gamma_table != NULL)
- {
- sp = row;
- for (i = 0; i < row_width; i++, sp += 3)
- {
- if (*sp == trans_values->red &&
- *(sp + 1) == trans_values->green &&
- *(sp + 2) == trans_values->blue)
- {
- *sp = (png_byte)background->red;
- *(sp + 1) = (png_byte)background->green;
- *(sp + 2) = (png_byte)background->blue;
- }
- else
- {
- *sp = gamma_table[*sp];
- *(sp + 1) = gamma_table[*(sp + 1)];
- *(sp + 2) = gamma_table[*(sp + 2)];
- }
- }
- }
- else
-#endif
- {
- sp = row;
- for (i = 0; i < row_width; i++, sp += 3)
- {
- if (*sp == trans_values->red &&
- *(sp + 1) == trans_values->green &&
- *(sp + 2) == trans_values->blue)
- {
- *sp = (png_byte)background->red;
- *(sp + 1) = (png_byte)background->green;
- *(sp + 2) = (png_byte)background->blue;
- }
- }
- }
- }
- else /* if (row_info->bit_depth == 16) */
- {
-#if defined(PNG_READ_GAMMA_SUPPORTED)
- if (gamma_16 != NULL)
- {
- sp = row;
- for (i = 0; i < row_width; i++, sp += 6)
- {
- png_uint_16 r = (png_uint_16)(((*sp) << 8) + *(sp + 1));
- png_uint_16 g = (png_uint_16)(((*(sp+2)) << 8) + *(sp+3));
- png_uint_16 b = (png_uint_16)(((*(sp+4)) << 8) + *(sp+5));
- if (r == trans_values->red && g == trans_values->green &&
- b == trans_values->blue)
- {
- /* Background is already in screen gamma */
- *sp = (png_byte)((background->red >> 8) & 0xff);
- *(sp + 1) = (png_byte)(background->red & 0xff);
- *(sp + 2) = (png_byte)((background->green >> 8) & 0xff);
- *(sp + 3) = (png_byte)(background->green & 0xff);
- *(sp + 4) = (png_byte)((background->blue >> 8) & 0xff);
- *(sp + 5) = (png_byte)(background->blue & 0xff);
- }
- else
- {
- png_uint_16 v = gamma_16[*(sp + 1) >> gamma_shift][*sp];
- *sp = (png_byte)((v >> 8) & 0xff);
- *(sp + 1) = (png_byte)(v & 0xff);
- v = gamma_16[*(sp + 3) >> gamma_shift][*(sp + 2)];
- *(sp + 2) = (png_byte)((v >> 8) & 0xff);
- *(sp + 3) = (png_byte)(v & 0xff);
- v = gamma_16[*(sp + 5) >> gamma_shift][*(sp + 4)];
- *(sp + 4) = (png_byte)((v >> 8) & 0xff);
- *(sp + 5) = (png_byte)(v & 0xff);
- }
- }
- }
- else
-#endif
- {
- sp = row;
- for (i = 0; i < row_width; i++, sp += 6)
- {
- png_uint_16 r = (png_uint_16)(((*sp) << 8) + *(sp+1));
- png_uint_16 g = (png_uint_16)(((*(sp+2)) << 8) + *(sp+3));
- png_uint_16 b = (png_uint_16)(((*(sp+4)) << 8) + *(sp+5));
-
- if (r == trans_values->red && g == trans_values->green &&
- b == trans_values->blue)
- {
- *sp = (png_byte)((background->red >> 8) & 0xff);
- *(sp + 1) = (png_byte)(background->red & 0xff);
- *(sp + 2) = (png_byte)((background->green >> 8) & 0xff);
- *(sp + 3) = (png_byte)(background->green & 0xff);
- *(sp + 4) = (png_byte)((background->blue >> 8) & 0xff);
- *(sp + 5) = (png_byte)(background->blue & 0xff);
- }
- }
- }
- }
- break;
- }
-
- case PNG_COLOR_TYPE_GRAY_ALPHA:
- {
- if (row_info->bit_depth == 8)
- {
-#if defined(PNG_READ_GAMMA_SUPPORTED)
- if (gamma_to_1 != NULL && gamma_from_1 != NULL &&
- gamma_table != NULL)
- {
- sp = row;
- dp = row;
- for (i = 0; i < row_width; i++, sp += 2, dp++)
- {
- png_uint_16 a = *(sp + 1);
-
- if (a == 0xff)
- {
- *dp = gamma_table[*sp];
- }
- else if (a == 0)
- {
- /* Background is already in screen gamma */
- *dp = (png_byte)background->gray;
- }
- else
- {
- png_byte v, w;
-
- v = gamma_to_1[*sp];
- png_composite(w, v, a, background_1->gray);
- *dp = gamma_from_1[w];
- }
- }
- }
- else
-#endif
- {
- sp = row;
- dp = row;
- for (i = 0; i < row_width; i++, sp += 2, dp++)
- {
- png_byte a = *(sp + 1);
-
- if (a == 0xff)
- {
- *dp = *sp;
- }
-#if defined(PNG_READ_GAMMA_SUPPORTED)
- else if (a == 0)
- {
- *dp = (png_byte)background->gray;
- }
- else
- {
- png_composite(*dp, *sp, a, background_1->gray);
- }
-#else
- *dp = (png_byte)background->gray;
-#endif
- }
- }
- }
- else /* if (png_ptr->bit_depth == 16) */
- {
-#if defined(PNG_READ_GAMMA_SUPPORTED)
- if (gamma_16 != NULL && gamma_16_from_1 != NULL &&
- gamma_16_to_1 != NULL)
- {
- sp = row;
- dp = row;
- for (i = 0; i < row_width; i++, sp += 4, dp += 2)
- {
- png_uint_16 a = (png_uint_16)(((*(sp+2)) << 8) + *(sp+3));
-
- if (a == (png_uint_16)0xffff)
- {
- png_uint_16 v;
-
- v = gamma_16[*(sp + 1) >> gamma_shift][*sp];
- *dp = (png_byte)((v >> 8) & 0xff);
- *(dp + 1) = (png_byte)(v & 0xff);
- }
-#if defined(PNG_READ_GAMMA_SUPPORTED)
- else if (a == 0)
-#else
- else
-#endif
- {
- /* Background is already in screen gamma */
- *dp = (png_byte)((background->gray >> 8) & 0xff);
- *(dp + 1) = (png_byte)(background->gray & 0xff);
- }
-#if defined(PNG_READ_GAMMA_SUPPORTED)
- else
- {
- png_uint_16 g, v, w;
-
- g = gamma_16_to_1[*(sp + 1) >> gamma_shift][*sp];
- png_composite_16(v, g, a, background_1->gray);
- w = gamma_16_from_1[(v&0xff) >> gamma_shift][v >> 8];
- *dp = (png_byte)((w >> 8) & 0xff);
- *(dp + 1) = (png_byte)(w & 0xff);
- }
-#endif
- }
- }
- else
-#endif
- {
- sp = row;
- dp = row;
- for (i = 0; i < row_width; i++, sp += 4, dp += 2)
- {
- png_uint_16 a = (png_uint_16)(((*(sp+2)) << 8) + *(sp+3));
- if (a == (png_uint_16)0xffff)
- {
- png_memcpy(dp, sp, 2);
- }
-#if defined(PNG_READ_GAMMA_SUPPORTED)
- else if (a == 0)
-#else
- else
-#endif
- {
- *dp = (png_byte)((background->gray >> 8) & 0xff);
- *(dp + 1) = (png_byte)(background->gray & 0xff);
- }
-#if defined(PNG_READ_GAMMA_SUPPORTED)
- else
- {
- png_uint_16 g, v;
-
- g = (png_uint_16)(((*sp) << 8) + *(sp + 1));
- png_composite_16(v, g, a, background_1->gray);
- *dp = (png_byte)((v >> 8) & 0xff);
- *(dp + 1) = (png_byte)(v & 0xff);
- }
-#endif
- }
- }
- }
- break;
- }
-
- case PNG_COLOR_TYPE_RGB_ALPHA:
- {
- if (row_info->bit_depth == 8)
- {
-#if defined(PNG_READ_GAMMA_SUPPORTED)
- if (gamma_to_1 != NULL && gamma_from_1 != NULL &&
- gamma_table != NULL)
- {
- sp = row;
- dp = row;
- for (i = 0; i < row_width; i++, sp += 4, dp += 3)
- {
- png_byte a = *(sp + 3);
-
- if (a == 0xff)
- {
- *dp = gamma_table[*sp];
- *(dp + 1) = gamma_table[*(sp + 1)];
- *(dp + 2) = gamma_table[*(sp + 2)];
- }
- else if (a == 0)
- {
- /* Background is already in screen gamma */
- *dp = (png_byte)background->red;
- *(dp + 1) = (png_byte)background->green;
- *(dp + 2) = (png_byte)background->blue;
- }
- else
- {
- png_byte v, w;
-
- v = gamma_to_1[*sp];
- png_composite(w, v, a, background_1->red);
- *dp = gamma_from_1[w];
- v = gamma_to_1[*(sp + 1)];
- png_composite(w, v, a, background_1->green);
- *(dp + 1) = gamma_from_1[w];
- v = gamma_to_1[*(sp + 2)];
- png_composite(w, v, a, background_1->blue);
- *(dp + 2) = gamma_from_1[w];
- }
- }
- }
- else
-#endif
- {
- sp = row;
- dp = row;
- for (i = 0; i < row_width; i++, sp += 4, dp += 3)
- {
- png_byte a = *(sp + 3);
-
- if (a == 0xff)
- {
- *dp = *sp;
- *(dp + 1) = *(sp + 1);
- *(dp + 2) = *(sp + 2);
- }
- else if (a == 0)
- {
- *dp = (png_byte)background->red;
- *(dp + 1) = (png_byte)background->green;
- *(dp + 2) = (png_byte)background->blue;
- }
- else
- {
- png_composite(*dp, *sp, a, background->red);
- png_composite(*(dp + 1), *(sp + 1), a,
- background->green);
- png_composite(*(dp + 2), *(sp + 2), a,
- background->blue);
- }
- }
- }
- }
- else /* if (row_info->bit_depth == 16) */
- {
-#if defined(PNG_READ_GAMMA_SUPPORTED)
- if (gamma_16 != NULL && gamma_16_from_1 != NULL &&
- gamma_16_to_1 != NULL)
- {
- sp = row;
- dp = row;
- for (i = 0; i < row_width; i++, sp += 8, dp += 6)
- {
- png_uint_16 a = (png_uint_16)(((png_uint_16)(*(sp + 6))
- << 8) + (png_uint_16)(*(sp + 7)));
- if (a == (png_uint_16)0xffff)
- {
- png_uint_16 v;
-
- v = gamma_16[*(sp + 1) >> gamma_shift][*sp];
- *dp = (png_byte)((v >> 8) & 0xff);
- *(dp + 1) = (png_byte)(v & 0xff);
- v = gamma_16[*(sp + 3) >> gamma_shift][*(sp + 2)];
- *(dp + 2) = (png_byte)((v >> 8) & 0xff);
- *(dp + 3) = (png_byte)(v & 0xff);
- v = gamma_16[*(sp + 5) >> gamma_shift][*(sp + 4)];
- *(dp + 4) = (png_byte)((v >> 8) & 0xff);
- *(dp + 5) = (png_byte)(v & 0xff);
- }
- else if (a == 0)
- {
- /* Background is already in screen gamma */
- *dp = (png_byte)((background->red >> 8) & 0xff);
- *(dp + 1) = (png_byte)(background->red & 0xff);
- *(dp + 2) = (png_byte)((background->green >> 8) & 0xff);
- *(dp + 3) = (png_byte)(background->green & 0xff);
- *(dp + 4) = (png_byte)((background->blue >> 8) & 0xff);
- *(dp + 5) = (png_byte)(background->blue & 0xff);
- }
- else
- {
- png_uint_16 v, w, x;
-
- v = gamma_16_to_1[*(sp + 1) >> gamma_shift][*sp];
- png_composite_16(w, v, a, background_1->red);
- x = gamma_16_from_1[((w&0xff) >> gamma_shift)][w >> 8];
- *dp = (png_byte)((x >> 8) & 0xff);
- *(dp + 1) = (png_byte)(x & 0xff);
- v = gamma_16_to_1[*(sp + 3) >> gamma_shift][*(sp + 2)];
- png_composite_16(w, v, a, background_1->green);
- x = gamma_16_from_1[((w&0xff) >> gamma_shift)][w >> 8];
- *(dp + 2) = (png_byte)((x >> 8) & 0xff);
- *(dp + 3) = (png_byte)(x & 0xff);
- v = gamma_16_to_1[*(sp + 5) >> gamma_shift][*(sp + 4)];
- png_composite_16(w, v, a, background_1->blue);
- x = gamma_16_from_1[(w & 0xff) >> gamma_shift][w >> 8];
- *(dp + 4) = (png_byte)((x >> 8) & 0xff);
- *(dp + 5) = (png_byte)(x & 0xff);
- }
- }
- }
- else
-#endif
- {
- sp = row;
- dp = row;
- for (i = 0; i < row_width; i++, sp += 8, dp += 6)
- {
- png_uint_16 a = (png_uint_16)(((png_uint_16)(*(sp + 6))
- << 8) + (png_uint_16)(*(sp + 7)));
- if (a == (png_uint_16)0xffff)
- {
- png_memcpy(dp, sp, 6);
- }
- else if (a == 0)
- {
- *dp = (png_byte)((background->red >> 8) & 0xff);
- *(dp + 1) = (png_byte)(background->red & 0xff);
- *(dp + 2) = (png_byte)((background->green >> 8) & 0xff);
- *(dp + 3) = (png_byte)(background->green & 0xff);
- *(dp + 4) = (png_byte)((background->blue >> 8) & 0xff);
- *(dp + 5) = (png_byte)(background->blue & 0xff);
- }
- else
- {
- png_uint_16 v;
-
- png_uint_16 r = (png_uint_16)(((*sp) << 8) + *(sp + 1));
- png_uint_16 g = (png_uint_16)(((*(sp + 2)) << 8)
- + *(sp + 3));
- png_uint_16 b = (png_uint_16)(((*(sp + 4)) << 8)
- + *(sp + 5));
-
- png_composite_16(v, r, a, background->red);
- *dp = (png_byte)((v >> 8) & 0xff);
- *(dp + 1) = (png_byte)(v & 0xff);
- png_composite_16(v, g, a, background->green);
- *(dp + 2) = (png_byte)((v >> 8) & 0xff);
- *(dp + 3) = (png_byte)(v & 0xff);
- png_composite_16(v, b, a, background->blue);
- *(dp + 4) = (png_byte)((v >> 8) & 0xff);
- *(dp + 5) = (png_byte)(v & 0xff);
- }
- }
- }
- }
- break;
- }
- }
-
- if (row_info->color_type & PNG_COLOR_MASK_ALPHA)
- {
- row_info->color_type &= ~PNG_COLOR_MASK_ALPHA;
- row_info->channels--;
- row_info->pixel_depth = (png_byte)(row_info->channels *
- row_info->bit_depth);
- row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width);
- }
- }
-}
-#endif
-
-#if defined(PNG_READ_GAMMA_SUPPORTED)
-/* Gamma correct the image, avoiding the alpha channel. Make sure
- * you do this after you deal with the transparency issue on grayscale
- * or RGB images. If your bit depth is 8, use gamma_table, if it
- * is 16, use gamma_16_table and gamma_shift. Build these with
- * build_gamma_table().
- */
-void /* PRIVATE */
-png_do_gamma(png_row_infop row_info, png_bytep row,
- png_bytep gamma_table, png_uint_16pp gamma_16_table,
- int gamma_shift)
-{
- png_bytep sp;
- png_uint_32 i;
- png_uint_32 row_width=row_info->width;
-
- png_debug(1, "in png_do_gamma");
- if (
-#if defined(PNG_USELESS_TESTS_SUPPORTED)
- row != NULL && row_info != NULL &&
-#endif
- ((row_info->bit_depth <= 8 && gamma_table != NULL) ||
- (row_info->bit_depth == 16 && gamma_16_table != NULL)))
- {
- switch (row_info->color_type)
- {
- case PNG_COLOR_TYPE_RGB:
- {
- if (row_info->bit_depth == 8)
- {
- sp = row;
- for (i = 0; i < row_width; i++)
- {
- *sp = gamma_table[*sp];
- sp++;
- *sp = gamma_table[*sp];
- sp++;
- *sp = gamma_table[*sp];
- sp++;
- }
- }
- else /* if (row_info->bit_depth == 16) */
- {
- sp = row;
- for (i = 0; i < row_width; i++)
- {
- png_uint_16 v;
-
- v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
- *sp = (png_byte)((v >> 8) & 0xff);
- *(sp + 1) = (png_byte)(v & 0xff);
- sp += 2;
- v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
- *sp = (png_byte)((v >> 8) & 0xff);
- *(sp + 1) = (png_byte)(v & 0xff);
- sp += 2;
- v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
- *sp = (png_byte)((v >> 8) & 0xff);
- *(sp + 1) = (png_byte)(v & 0xff);
- sp += 2;
- }
- }
- break;
- }
-
- case PNG_COLOR_TYPE_RGB_ALPHA:
- {
- if (row_info->bit_depth == 8)
- {
- sp = row;
- for (i = 0; i < row_width; i++)
- {
- *sp = gamma_table[*sp];
- sp++;
- *sp = gamma_table[*sp];
- sp++;
- *sp = gamma_table[*sp];
- sp++;
- sp++;
- }
- }
- else /* if (row_info->bit_depth == 16) */
- {
- sp = row;
- for (i = 0; i < row_width; i++)
- {
- png_uint_16 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
- *sp = (png_byte)((v >> 8) & 0xff);
- *(sp + 1) = (png_byte)(v & 0xff);
- sp += 2;
- v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
- *sp = (png_byte)((v >> 8) & 0xff);
- *(sp + 1) = (png_byte)(v & 0xff);
- sp += 2;
- v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
- *sp = (png_byte)((v >> 8) & 0xff);
- *(sp + 1) = (png_byte)(v & 0xff);
- sp += 4;
- }
- }
- break;
- }
-
- case PNG_COLOR_TYPE_GRAY_ALPHA:
- {
- if (row_info->bit_depth == 8)
- {
- sp = row;
- for (i = 0; i < row_width; i++)
- {
- *sp = gamma_table[*sp];
- sp += 2;
- }
- }
- else /* if (row_info->bit_depth == 16) */
- {
- sp = row;
- for (i = 0; i < row_width; i++)
- {
- png_uint_16 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
- *sp = (png_byte)((v >> 8) & 0xff);
- *(sp + 1) = (png_byte)(v & 0xff);
- sp += 4;
- }
- }
- break;
- }
-
- case PNG_COLOR_TYPE_GRAY:
- {
- if (row_info->bit_depth == 2)
- {
- sp = row;
- for (i = 0; i < row_width; i += 4)
- {
- int a = *sp & 0xc0;
- int b = *sp & 0x30;
- int c = *sp & 0x0c;
- int d = *sp & 0x03;
-
- *sp = (png_byte)(
- ((((int)gamma_table[a|(a>>2)|(a>>4)|(a>>6)]) ) & 0xc0)|
- ((((int)gamma_table[(b<<2)|b|(b>>2)|(b>>4)])>>2) & 0x30)|
- ((((int)gamma_table[(c<<4)|(c<<2)|c|(c>>2)])>>4) & 0x0c)|
- ((((int)gamma_table[(d<<6)|(d<<4)|(d<<2)|d])>>6) ));
- sp++;
- }
- }
-
- if (row_info->bit_depth == 4)
- {
- sp = row;
- for (i = 0; i < row_width; i += 2)
- {
- int msb = *sp & 0xf0;
- int lsb = *sp & 0x0f;
-
- *sp = (png_byte)((((int)gamma_table[msb | (msb >> 4)]) & 0xf0)
- | (((int)gamma_table[(lsb << 4) | lsb]) >> 4));
- sp++;
- }
- }
-
- else if (row_info->bit_depth == 8)
- {
- sp = row;
- for (i = 0; i < row_width; i++)
- {
- *sp = gamma_table[*sp];
- sp++;
- }
- }
-
- else if (row_info->bit_depth == 16)
- {
- sp = row;
- for (i = 0; i < row_width; i++)
- {
- png_uint_16 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
- *sp = (png_byte)((v >> 8) & 0xff);
- *(sp + 1) = (png_byte)(v & 0xff);
- sp += 2;
- }
- }
- break;
- }
- }
- }
-}
-#endif
-
-#if defined(PNG_READ_EXPAND_SUPPORTED)
-/* Expands a palette row to an RGB or RGBA row depending
- * upon whether you supply trans and num_trans.
- */
-void /* PRIVATE */
-png_do_expand_palette(png_row_infop row_info, png_bytep row,
- png_colorp palette, png_bytep trans, int num_trans)
-{
- int shift, value;
- png_bytep sp, dp;
- png_uint_32 i;
- png_uint_32 row_width=row_info->width;
-
- png_debug(1, "in png_do_expand_palette");
- if (
-#if defined(PNG_USELESS_TESTS_SUPPORTED)
- row != NULL && row_info != NULL &&
-#endif
- row_info->color_type == PNG_COLOR_TYPE_PALETTE)
- {
- if (row_info->bit_depth < 8)
- {
- switch (row_info->bit_depth)
- {
- case 1:
- {
- sp = row + (png_size_t)((row_width - 1) >> 3);
- dp = row + (png_size_t)row_width - 1;
- shift = 7 - (int)((row_width + 7) & 0x07);
- for (i = 0; i < row_width; i++)
- {
- if ((*sp >> shift) & 0x01)
- *dp = 1;
- else
- *dp = 0;
- if (shift == 7)
- {
- shift = 0;
- sp--;
- }
- else
- shift++;
-
- dp--;
- }
- break;
- }
-
- case 2:
- {
- sp = row + (png_size_t)((row_width - 1) >> 2);
- dp = row + (png_size_t)row_width - 1;
- shift = (int)((3 - ((row_width + 3) & 0x03)) << 1);
- for (i = 0; i < row_width; i++)
- {
- value = (*sp >> shift) & 0x03;
- *dp = (png_byte)value;
- if (shift == 6)
- {
- shift = 0;
- sp--;
- }
- else
- shift += 2;
-
- dp--;
- }
- break;
- }
-
- case 4:
- {
- sp = row + (png_size_t)((row_width - 1) >> 1);
- dp = row + (png_size_t)row_width - 1;
- shift = (int)((row_width & 0x01) << 2);
- for (i = 0; i < row_width; i++)
- {
- value = (*sp >> shift) & 0x0f;
- *dp = (png_byte)value;
- if (shift == 4)
- {
- shift = 0;
- sp--;
- }
- else
- shift += 4;
-
- dp--;
- }
- break;
- }
- }
- row_info->bit_depth = 8;
- row_info->pixel_depth = 8;
- row_info->rowbytes = row_width;
- }
- switch (row_info->bit_depth)
- {
- case 8:
- {
- if (trans != NULL)
- {
- sp = row + (png_size_t)row_width - 1;
- dp = row + (png_size_t)(row_width << 2) - 1;
-
- for (i = 0; i < row_width; i++)
- {
- if ((int)(*sp) >= num_trans)
- *dp-- = 0xff;
- else
- *dp-- = trans[*sp];
- *dp-- = palette[*sp].blue;
- *dp-- = palette[*sp].green;
- *dp-- = palette[*sp].red;
- sp--;
- }
- row_info->bit_depth = 8;
- row_info->pixel_depth = 32;
- row_info->rowbytes = row_width * 4;
- row_info->color_type = 6;
- row_info->channels = 4;
- }
- else
- {
- sp = row + (png_size_t)row_width - 1;
- dp = row + (png_size_t)(row_width * 3) - 1;
-
- for (i = 0; i < row_width; i++)
- {
- *dp-- = palette[*sp].blue;
- *dp-- = palette[*sp].green;
- *dp-- = palette[*sp].red;
- sp--;
- }
-
- row_info->bit_depth = 8;
- row_info->pixel_depth = 24;
- row_info->rowbytes = row_width * 3;
- row_info->color_type = 2;
- row_info->channels = 3;
- }
- break;
- }
- }
- }
-}
-
-/* If the bit depth < 8, it is expanded to 8. Also, if the already
- * expanded transparency value is supplied, an alpha channel is built.
- */
-void /* PRIVATE */
-png_do_expand(png_row_infop row_info, png_bytep row,
- png_color_16p trans_value)
-{
- int shift, value;
- png_bytep sp, dp;
- png_uint_32 i;
- png_uint_32 row_width=row_info->width;
-
- png_debug(1, "in png_do_expand");
-#if defined(PNG_USELESS_TESTS_SUPPORTED)
- if (row != NULL && row_info != NULL)
-#endif
- {
- if (row_info->color_type == PNG_COLOR_TYPE_GRAY)
- {
- png_uint_16 gray = (png_uint_16)(trans_value ? trans_value->gray : 0);
-
- if (row_info->bit_depth < 8)
- {
- switch (row_info->bit_depth)
- {
- case 1:
- {
- gray = (png_uint_16)((gray&0x01)*0xff);
- sp = row + (png_size_t)((row_width - 1) >> 3);
- dp = row + (png_size_t)row_width - 1;
- shift = 7 - (int)((row_width + 7) & 0x07);
- for (i = 0; i < row_width; i++)
- {
- if ((*sp >> shift) & 0x01)
- *dp = 0xff;
- else
- *dp = 0;
- if (shift == 7)
- {
- shift = 0;
- sp--;
- }
- else
- shift++;
-
- dp--;
- }
- break;
- }
-
- case 2:
- {
- gray = (png_uint_16)((gray&0x03)*0x55);
- sp = row + (png_size_t)((row_width - 1) >> 2);
- dp = row + (png_size_t)row_width - 1;
- shift = (int)((3 - ((row_width + 3) & 0x03)) << 1);
- for (i = 0; i < row_width; i++)
- {
- value = (*sp >> shift) & 0x03;
- *dp = (png_byte)(value | (value << 2) | (value << 4) |
- (value << 6));
- if (shift == 6)
- {
- shift = 0;
- sp--;
- }
- else
- shift += 2;
-
- dp--;
- }
- break;
- }
-
- case 4:
- {
- gray = (png_uint_16)((gray&0x0f)*0x11);
- sp = row + (png_size_t)((row_width - 1) >> 1);
- dp = row + (png_size_t)row_width - 1;
- shift = (int)((1 - ((row_width + 1) & 0x01)) << 2);
- for (i = 0; i < row_width; i++)
- {
- value = (*sp >> shift) & 0x0f;
- *dp = (png_byte)(value | (value << 4));
- if (shift == 4)
- {
- shift = 0;
- sp--;
- }
- else
- shift = 4;
-
- dp--;
- }
- break;
- }
- }
-
- row_info->bit_depth = 8;
- row_info->pixel_depth = 8;
- row_info->rowbytes = row_width;
- }
-
- if (trans_value != NULL)
- {
- if (row_info->bit_depth == 8)
- {
- gray = gray & 0xff;
- sp = row + (png_size_t)row_width - 1;
- dp = row + (png_size_t)(row_width << 1) - 1;
- for (i = 0; i < row_width; i++)
- {
- if (*sp == gray)
- *dp-- = 0;
- else
- *dp-- = 0xff;
- *dp-- = *sp--;
- }
- }
-
- else if (row_info->bit_depth == 16)
- {
- png_byte gray_high = (gray >> 8) & 0xff;
- png_byte gray_low = gray & 0xff;
- sp = row + row_info->rowbytes - 1;
- dp = row + (row_info->rowbytes << 1) - 1;
- for (i = 0; i < row_width; i++)
- {
- if (*(sp - 1) == gray_high && *(sp) == gray_low)
- {
- *dp-- = 0;
- *dp-- = 0;
- }
- else
- {
- *dp-- = 0xff;
- *dp-- = 0xff;
- }
- *dp-- = *sp--;
- *dp-- = *sp--;
- }
- }
-
- row_info->color_type = PNG_COLOR_TYPE_GRAY_ALPHA;
- row_info->channels = 2;
- row_info->pixel_depth = (png_byte)(row_info->bit_depth << 1);
- row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth,
- row_width);
- }
- }
- else if (row_info->color_type == PNG_COLOR_TYPE_RGB && trans_value)
- {
- if (row_info->bit_depth == 8)
- {
- png_byte red = trans_value->red & 0xff;
- png_byte green = trans_value->green & 0xff;
- png_byte blue = trans_value->blue & 0xff;
- sp = row + (png_size_t)row_info->rowbytes - 1;
- dp = row + (png_size_t)(row_width << 2) - 1;
- for (i = 0; i < row_width; i++)
- {
- if (*(sp - 2) == red && *(sp - 1) == green && *(sp) == blue)
- *dp-- = 0;
- else
- *dp-- = 0xff;
- *dp-- = *sp--;
- *dp-- = *sp--;
- *dp-- = *sp--;
- }
- }
- else if (row_info->bit_depth == 16)
- {
- png_byte red_high = (trans_value->red >> 8) & 0xff;
- png_byte green_high = (trans_value->green >> 8) & 0xff;
- png_byte blue_high = (trans_value->blue >> 8) & 0xff;
- png_byte red_low = trans_value->red & 0xff;
- png_byte green_low = trans_value->green & 0xff;
- png_byte blue_low = trans_value->blue & 0xff;
- sp = row + row_info->rowbytes - 1;
- dp = row + (png_size_t)(row_width << 3) - 1;
- for (i = 0; i < row_width; i++)
- {
- if (*(sp - 5) == red_high &&
- *(sp - 4) == red_low &&
- *(sp - 3) == green_high &&
- *(sp - 2) == green_low &&
- *(sp - 1) == blue_high &&
- *(sp ) == blue_low)
- {
- *dp-- = 0;
- *dp-- = 0;
- }
- else
- {
- *dp-- = 0xff;
- *dp-- = 0xff;
- }
- *dp-- = *sp--;
- *dp-- = *sp--;
- *dp-- = *sp--;
- *dp-- = *sp--;
- *dp-- = *sp--;
- *dp-- = *sp--;
- }
- }
- row_info->color_type = PNG_COLOR_TYPE_RGB_ALPHA;
- row_info->channels = 4;
- row_info->pixel_depth = (png_byte)(row_info->bit_depth << 2);
- row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width);
- }
- }
-}
-#endif
-
-#if defined(PNG_READ_DITHER_SUPPORTED)
-void /* PRIVATE */
-png_do_dither(png_row_infop row_info, png_bytep row,
- png_bytep palette_lookup, png_bytep dither_lookup)
-{
- png_bytep sp, dp;
- png_uint_32 i;
- png_uint_32 row_width=row_info->width;
-
- png_debug(1, "in png_do_dither");
-#if defined(PNG_USELESS_TESTS_SUPPORTED)
- if (row != NULL && row_info != NULL)
-#endif
- {
- if (row_info->color_type == PNG_COLOR_TYPE_RGB &&
- palette_lookup && row_info->bit_depth == 8)
- {
- int r, g, b, p;
- sp = row;
- dp = row;
- for (i = 0; i < row_width; i++)
- {
- r = *sp++;
- g = *sp++;
- b = *sp++;
-
- /* This looks real messy, but the compiler will reduce
- * it down to a reasonable formula. For example, with
- * 5 bits per color, we get:
- * p = (((r >> 3) & 0x1f) << 10) |
- * (((g >> 3) & 0x1f) << 5) |
- * ((b >> 3) & 0x1f);
- */
- p = (((r >> (8 - PNG_DITHER_RED_BITS)) &
- ((1 << PNG_DITHER_RED_BITS) - 1)) <<
- (PNG_DITHER_GREEN_BITS + PNG_DITHER_BLUE_BITS)) |
- (((g >> (8 - PNG_DITHER_GREEN_BITS)) &
- ((1 << PNG_DITHER_GREEN_BITS) - 1)) <<
- (PNG_DITHER_BLUE_BITS)) |
- ((b >> (8 - PNG_DITHER_BLUE_BITS)) &
- ((1 << PNG_DITHER_BLUE_BITS) - 1));
-
- *dp++ = palette_lookup[p];
- }
- row_info->color_type = PNG_COLOR_TYPE_PALETTE;
- row_info->channels = 1;
- row_info->pixel_depth = row_info->bit_depth;
- row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width);
- }
- else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA &&
- palette_lookup != NULL && row_info->bit_depth == 8)
- {
- int r, g, b, p;
- sp = row;
- dp = row;
- for (i = 0; i < row_width; i++)
- {
- r = *sp++;
- g = *sp++;
- b = *sp++;
- sp++;
-
- p = (((r >> (8 - PNG_DITHER_RED_BITS)) &
- ((1 << PNG_DITHER_RED_BITS) - 1)) <<
- (PNG_DITHER_GREEN_BITS + PNG_DITHER_BLUE_BITS)) |
- (((g >> (8 - PNG_DITHER_GREEN_BITS)) &
- ((1 << PNG_DITHER_GREEN_BITS) - 1)) <<
- (PNG_DITHER_BLUE_BITS)) |
- ((b >> (8 - PNG_DITHER_BLUE_BITS)) &
- ((1 << PNG_DITHER_BLUE_BITS) - 1));
-
- *dp++ = palette_lookup[p];
- }
- row_info->color_type = PNG_COLOR_TYPE_PALETTE;
- row_info->channels = 1;
- row_info->pixel_depth = row_info->bit_depth;
- row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width);
- }
- else if (row_info->color_type == PNG_COLOR_TYPE_PALETTE &&
- dither_lookup && row_info->bit_depth == 8)
- {
- sp = row;
- for (i = 0; i < row_width; i++, sp++)
- {
- *sp = dither_lookup[*sp];
- }
- }
- }
-}
-#endif
-
-#ifdef PNG_FLOATING_POINT_SUPPORTED
-#if defined(PNG_READ_GAMMA_SUPPORTED)
-static PNG_CONST int png_gamma_shift[] =
- {0x10, 0x21, 0x42, 0x84, 0x110, 0x248, 0x550, 0xff0, 0x00};
-
-/* We build the 8- or 16-bit gamma tables here. Note that for 16-bit
- * tables, we don't make a full table if we are reducing to 8-bit in
- * the future. Note also how the gamma_16 tables are segmented so that
- * we don't need to allocate > 64K chunks for a full 16-bit table.
- */
-void /* PRIVATE */
-png_build_gamma_table(png_structp png_ptr)
-{
- png_debug(1, "in png_build_gamma_table");
-
- if (png_ptr->bit_depth <= 8)
- {
- int i;
- double g;
-
- if (png_ptr->screen_gamma > .000001)
- g = 1.0 / (png_ptr->gamma * png_ptr->screen_gamma);
-
- else
- g = 1.0;
-
- png_ptr->gamma_table = (png_bytep)png_malloc(png_ptr,
- (png_uint_32)256);
-
- for (i = 0; i < 256; i++)
- {
- png_ptr->gamma_table[i] = (png_byte)(pow((double)i / 255.0,
- g) * 255.0 + .5);
- }
-
-#if defined(PNG_READ_BACKGROUND_SUPPORTED) || \
- defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
- if (png_ptr->transformations & ((PNG_BACKGROUND) | PNG_RGB_TO_GRAY))
- {
-
- g = 1.0 / (png_ptr->gamma);
-
- png_ptr->gamma_to_1 = (png_bytep)png_malloc(png_ptr,
- (png_uint_32)256);
-
- for (i = 0; i < 256; i++)
- {
- png_ptr->gamma_to_1[i] = (png_byte)(pow((double)i / 255.0,
- g) * 255.0 + .5);
- }
-
-
- png_ptr->gamma_from_1 = (png_bytep)png_malloc(png_ptr,
- (png_uint_32)256);
-
- if (png_ptr->screen_gamma > 0.000001)
- g = 1.0 / png_ptr->screen_gamma;
-
- else
- g = png_ptr->gamma; /* Probably doing rgb_to_gray */
-
- for (i = 0; i < 256; i++)
- {
- png_ptr->gamma_from_1[i] = (png_byte)(pow((double)i / 255.0,
- g) * 255.0 + .5);
-
- }
- }
-#endif /* PNG_READ_BACKGROUND_SUPPORTED || PNG_RGB_TO_GRAY_SUPPORTED */
- }
- else
- {
- double g;
- int i, j, shift, num;
- int sig_bit;
- png_uint_32 ig;
-
- if (png_ptr->color_type & PNG_COLOR_MASK_COLOR)
- {
- sig_bit = (int)png_ptr->sig_bit.red;
-
- if ((int)png_ptr->sig_bit.green > sig_bit)
- sig_bit = png_ptr->sig_bit.green;
-
- if ((int)png_ptr->sig_bit.blue > sig_bit)
- sig_bit = png_ptr->sig_bit.blue;
- }
- else
- {
- sig_bit = (int)png_ptr->sig_bit.gray;
- }
-
- if (sig_bit > 0)
- shift = 16 - sig_bit;
-
- else
- shift = 0;
-
- if (png_ptr->transformations & PNG_16_TO_8)
- {
- if (shift < (16 - PNG_MAX_GAMMA_8))
- shift = (16 - PNG_MAX_GAMMA_8);
- }
-
- if (shift > 8)
- shift = 8;
-
- if (shift < 0)
- shift = 0;
-
- png_ptr->gamma_shift = (png_byte)shift;
-
- num = (1 << (8 - shift));
-
- if (png_ptr->screen_gamma > .000001)
- g = 1.0 / (png_ptr->gamma * png_ptr->screen_gamma);
- else
- g = 1.0;
-
- png_ptr->gamma_16_table = (png_uint_16pp)png_malloc(png_ptr,
- (png_uint_32)(num * png_sizeof(png_uint_16p)));
- png_memset(png_ptr->gamma_16_table, 0, num * png_sizeof(png_uint_16p));
-
- if (png_ptr->transformations & (PNG_16_TO_8 | PNG_BACKGROUND))
- {
- double fin, fout;
- png_uint_32 last, max;
-
- for (i = 0; i < num; i++)
- {
- png_ptr->gamma_16_table[i] = (png_uint_16p)png_malloc(png_ptr,
- (png_uint_32)(256 * png_sizeof(png_uint_16)));
- }
-
- g = 1.0 / g;
- last = 0;
- for (i = 0; i < 256; i++)
- {
- fout = ((double)i + 0.5) / 256.0;
- fin = pow(fout, g);
- max = (png_uint_32)(fin * (double)((png_uint_32)num << 8));
- while (last <= max)
- {
- png_ptr->gamma_16_table[(int)(last & (0xff >> shift))]
- [(int)(last >> (8 - shift))] = (png_uint_16)(
- (png_uint_16)i | ((png_uint_16)i << 8));
- last++;
- }
- }
- while (last < ((png_uint_32)num << 8))
- {
- png_ptr->gamma_16_table[(int)(last & (0xff >> shift))]
- [(int)(last >> (8 - shift))] = (png_uint_16)65535L;
- last++;
- }
- }
- else
- {
- for (i = 0; i < num; i++)
- {
- png_ptr->gamma_16_table[i] = (png_uint_16p)png_malloc(png_ptr,
- (png_uint_32)(256 * png_sizeof(png_uint_16)));
-
- ig = (((png_uint_32)i * (png_uint_32)png_gamma_shift[shift]) >> 4);
-
- for (j = 0; j < 256; j++)
- {
- png_ptr->gamma_16_table[i][j] =
- (png_uint_16)(pow((double)(ig + ((png_uint_32)j << 8)) /
- 65535.0, g) * 65535.0 + .5);
- }
- }
- }
-
-#if defined(PNG_READ_BACKGROUND_SUPPORTED) || \
- defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
- if (png_ptr->transformations & (PNG_BACKGROUND | PNG_RGB_TO_GRAY))
- {
-
- g = 1.0 / (png_ptr->gamma);
-
- png_ptr->gamma_16_to_1 = (png_uint_16pp)png_malloc(png_ptr,
- (png_uint_32)(num * png_sizeof(png_uint_16p )));
- png_memset(png_ptr->gamma_16_to_1, 0, num * png_sizeof(png_uint_16p));
-
- for (i = 0; i < num; i++)
- {
- png_ptr->gamma_16_to_1[i] = (png_uint_16p)png_malloc(png_ptr,
- (png_uint_32)(256 * png_sizeof(png_uint_16)));
-
- ig = (((png_uint_32)i *
- (png_uint_32)png_gamma_shift[shift]) >> 4);
- for (j = 0; j < 256; j++)
- {
- png_ptr->gamma_16_to_1[i][j] =
- (png_uint_16)(pow((double)(ig + ((png_uint_32)j << 8)) /
- 65535.0, g) * 65535.0 + .5);
- }
- }
-
- if (png_ptr->screen_gamma > 0.000001)
- g = 1.0 / png_ptr->screen_gamma;
-
- else
- g = png_ptr->gamma; /* Probably doing rgb_to_gray */
-
- png_ptr->gamma_16_from_1 = (png_uint_16pp)png_malloc(png_ptr,
- (png_uint_32)(num * png_sizeof(png_uint_16p)));
- png_memset(png_ptr->gamma_16_from_1, 0,
- num * png_sizeof(png_uint_16p));
-
- for (i = 0; i < num; i++)
- {
- png_ptr->gamma_16_from_1[i] = (png_uint_16p)png_malloc(png_ptr,
- (png_uint_32)(256 * png_sizeof(png_uint_16)));
-
- ig = (((png_uint_32)i *
- (png_uint_32)png_gamma_shift[shift]) >> 4);
-
- for (j = 0; j < 256; j++)
- {
- png_ptr->gamma_16_from_1[i][j] =
- (png_uint_16)(pow((double)(ig + ((png_uint_32)j << 8)) /
- 65535.0, g) * 65535.0 + .5);
- }
- }
- }
-#endif /* PNG_READ_BACKGROUND_SUPPORTED || PNG_RGB_TO_GRAY_SUPPORTED */
- }
-}
-#endif
-/* To do: install integer version of png_build_gamma_table here */
-#endif
-
-#if defined(PNG_MNG_FEATURES_SUPPORTED)
-/* Undoes intrapixel differencing */
-void /* PRIVATE */
-png_do_read_intrapixel(png_row_infop row_info, png_bytep row)
-{
- png_debug(1, "in png_do_read_intrapixel");
- if (
-#if defined(PNG_USELESS_TESTS_SUPPORTED)
- row != NULL && row_info != NULL &&
-#endif
- (row_info->color_type & PNG_COLOR_MASK_COLOR))
- {
- int bytes_per_pixel;
- png_uint_32 row_width = row_info->width;
- if (row_info->bit_depth == 8)
- {
- png_bytep rp;
- png_uint_32 i;
-
- if (row_info->color_type == PNG_COLOR_TYPE_RGB)
- bytes_per_pixel = 3;
-
- else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
- bytes_per_pixel = 4;
-
- else
- return;
-
- for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel)
- {
- *(rp) = (png_byte)((256 + *rp + *(rp+1))&0xff);
- *(rp+2) = (png_byte)((256 + *(rp+2) + *(rp+1))&0xff);
- }
- }
- else if (row_info->bit_depth == 16)
- {
- png_bytep rp;
- png_uint_32 i;
-
- if (row_info->color_type == PNG_COLOR_TYPE_RGB)
- bytes_per_pixel = 6;
-
- else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
- bytes_per_pixel = 8;
-
- else
- return;
-
- for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel)
- {
- png_uint_32 s0 = (*(rp ) << 8) | *(rp + 1);
- png_uint_32 s1 = (*(rp + 2) << 8) | *(rp + 3);
- png_uint_32 s2 = (*(rp + 4) << 8) | *(rp + 5);
- png_uint_32 red = (png_uint_32)((s0 + s1 + 65536L) & 0xffffL);
- png_uint_32 blue = (png_uint_32)((s2 + s1 + 65536L) & 0xffffL);
- *(rp ) = (png_byte)((red >> 8) & 0xff);
- *(rp+1) = (png_byte)(red & 0xff);
- *(rp+4) = (png_byte)((blue >> 8) & 0xff);
- *(rp+5) = (png_byte)(blue & 0xff);
- }
- }
- }
-}
-#endif /* PNG_MNG_FEATURES_SUPPORTED */
-#endif /* PNG_READ_SUPPORTED */
generated by cgit v0.12 at 2024-12-27 08:38:14 (GMT)