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Imported from libpng-0.98.tar

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This commit is contained in:
Glenn Randers-Pehrson
1998-01-16 22:06:18 -06:00
parent 2687fcc7b5
commit c4a2ae6cac
26 changed files with 687 additions and 240 deletions
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134
pngrtran.c
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@@ -1,12 +1,12 @@
/* pngrtran.c - transforms the data in a row for PNG readers
*
* libpng 0.97
* libpng 0.98
* For conditions of distribution and use, see copyright notice in png.h
* Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
* Copyright (c) 1996, 1997 Andreas Dilger
* Copyright (c) 1998, Glenn Randers-Pehrson
* January 7, 1998
* January 16, 1998
*
* This file contains functions optionally called by an application
* in order to tell libpng how to handle data when reading a PNG.
@@ -549,13 +549,13 @@ png_set_dither(png_structp png_ptr, png_colorp palette,
* also needlessly introduces small errors.
*/
void
png_set_gamma(png_structp png_ptr, double screen_gamma, double file_gamma)
png_set_gamma(png_structp png_ptr, double scrn_gamma, double file_gamma)
{
png_debug(1, "in png_set_gamma\n");
if (fabs(screen_gamma * file_gamma - 1.0) > PNG_GAMMA_THRESHOLD)
if (fabs(scrn_gamma * file_gamma - 1.0) > PNG_GAMMA_THRESHOLD)
png_ptr->transformations |= PNG_GAMMA;
png_ptr->gamma = (float)file_gamma;
png_ptr->display_gamma = (float)screen_gamma;
png_ptr->screen_gamma = (float)scrn_gamma;
}
#endif
@@ -592,6 +592,7 @@ png_set_rgb_to_gray(png_structp png_ptr, int gray_bits)
png_debug(1, "in png_set_rgb_to_gray\n");
png_ptr->transformations |= PNG_RGB_TO_GRAY;
/* Need to do something with gray_bits here. */
png_warning(png_ptr, "RGB to GRAY transformation is not yet implemented.");
}
#endif
@@ -644,6 +645,23 @@ png_init_read_transformations(png_structp png_ptr)
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)
#endif
{
/* invert the alpha channel (in tRNS) unless the pixels are
going to be expanded, in which case leave it for later */
int i;
for (i=0; i<png_ptr->num_trans; i++)
png_ptr->trans[i] = 255 - png_ptr->trans[i];
}
}
#endif
}
}
#endif
@@ -681,7 +699,7 @@ png_init_read_transformations(png_structp png_ptr)
{
double g;
g = 1.0 / (png_ptr->background_gamma * png_ptr->display_gamma);
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)
@@ -761,17 +779,17 @@ png_init_read_transformations(png_structp png_ptr)
switch (png_ptr->background_gamma_type)
{
case PNG_BACKGROUND_GAMMA_SCREEN:
g = (png_ptr->display_gamma);
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->display_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->display_gamma);
png_ptr->screen_gamma);
break;
}
@@ -954,7 +972,7 @@ png_read_transform_info(png_structp png_ptr, png_infop info_ptr)
else
info_ptr->channels = 1;
#if defined(PNG_STRIP_ALPHA_SUPPORTED)
#if defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
if ((png_ptr->transformations & PNG_STRIP_ALPHA) &&
info_ptr->color_type & PNG_COLOR_MASK_ALPHA)
{
@@ -1112,6 +1130,11 @@ png_do_read_transformations(png_structp png_ptr)
png_do_read_swap_alpha(&(png_ptr->row_info), png_ptr->row_buf + 1);
#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_SUPPORTED)
if (png_ptr->transformations & PNG_SWAP_BYTES)
png_do_swap(&(png_ptr->row_info), png_ptr->row_buf + 1);
@@ -1468,6 +1491,87 @@ png_do_read_swap_alpha(png_row_infop row_info, png_bytep row)
}
#endif
#if defined(PNG_READ_INVERT_ALPHA_SUPPORTED)
void
png_do_read_invert_alpha(png_row_infop row_info, png_bytep row)
{
png_debug(1, "in png_do_read_invert_alpha\n");
#if defined(PNG_USELESS_TESTS_SUPPORTED)
if (row != NULL && row_info != NULL)
#endif
{
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, dp;
png_uint_32 i;
for (i = 0, sp = dp = row + row_info->rowbytes;
i < row_info->width; i++)
{
*(--dp) = *(--sp);
*(--dp) = *(--sp);
*(--dp) = *(--sp);
*(--dp) = 255 - *(--sp);
}
}
/* This inverts the alpha channel in RRGGBBAA */
else
{
png_bytep sp, dp;
png_uint_32 i;
for (i = 0, sp = dp = row + row_info->rowbytes;
i < row_info->width; i++)
{
*(--dp) = *(--sp);
*(--dp) = *(--sp);
*(--dp) = *(--sp);
*(--dp) = *(--sp);
*(--dp) = *(--sp);
*(--dp) = *(--sp);
*(--dp) = 255 - *(--sp);
*(--dp) = 255 - *(--sp);
}
}
}
else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
{
/* This inverts the alpha channel in AG */
if (row_info->bit_depth == 8)
{
png_bytep sp, dp;
png_uint_32 i;
for (i = 0, sp = dp = row + row_info->rowbytes;
i < row_info->width; i++)
{
*(--dp) = *(--sp);
*(--dp) = 255 - *(--sp);
}
}
/* This inverts the alpha channel in AAGG */
else
{
png_bytep sp, dp;
png_uint_32 i;
for (i = 0, sp = dp = row + row_info->rowbytes;
i < row_info->width; i++)
{
*(--dp) = *(--sp);
*(--dp) = *(--sp);
*(--dp) = 255 - *(--sp);
*(--dp) = 255 - *(--sp);
}
}
}
}
}
#endif
#if defined(PNG_READ_FILLER_SUPPORTED)
/* Add filler channel if we have RGB color */
void
@@ -1693,7 +1797,7 @@ png_correct_palette(png_structp png_ptr, png_colorp palette,
{
double g;
g = 1.0 / (png_ptr->background_gamma * png_ptr->display_gamma);
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)
@@ -3082,7 +3186,7 @@ png_build_gamma_table(png_structp png_ptr)
int i;
double g;
g = 1.0 / (png_ptr->gamma * png_ptr->display_gamma);
g = 1.0 / (png_ptr->gamma * png_ptr->screen_gamma);
png_ptr->gamma_table = (png_bytep)png_malloc(png_ptr,
(png_uint_32)256);
@@ -3107,7 +3211,7 @@ png_build_gamma_table(png_structp png_ptr)
g) * 255.0 + .5);
}
g = 1.0 / (png_ptr->display_gamma);
g = 1.0 / (png_ptr->screen_gamma);
png_ptr->gamma_from_1 = (png_bytep)png_malloc(png_ptr,
(png_uint_32)256);
@@ -3160,7 +3264,7 @@ png_build_gamma_table(png_structp png_ptr)
num = (1 << (8 - shift));
g = 1.0 / (png_ptr->gamma * png_ptr->display_gamma);
g = 1.0 / (png_ptr->gamma * png_ptr->screen_gamma);
png_ptr->gamma_16_table = (png_uint_16pp)png_malloc(png_ptr,
num * sizeof (png_uint_16p));
@@ -3238,7 +3342,7 @@ png_build_gamma_table(png_structp png_ptr)
65535.0, g) * 65535.0 + .5);
}
}
g = 1.0 / (png_ptr->display_gamma);
g = 1.0 / (png_ptr->screen_gamma);
png_ptr->gamma_16_from_1 = (png_uint_16pp)png_malloc(png_ptr,
num * sizeof (png_uint_16p));