mewin/libpng
1
0
Fork 0
mirror of https://git.code.sf.net/p/libpng/code.git synced 2025-07-10 18:04:09 +02:00
Code Issues Projects Releases Wiki Activity

Imported from libpng-1.2.9beta8.tar

Browse Source
This commit is contained in:
Glenn Randers-Pehrson
2006-03-08 23:35:59 -06:00
parent 5c60b2367e
commit 1ce0836b4a
56 changed files with 296 additions and 216 deletions
Download Patch File Download Diff File Expand all files Collapse all files

68
pngrtran.c
View File

@@ -1,7 +1,7 @@
/* pngrtran.c - transforms the data in a row for PNG readers
*
* Last changed in libpng 1.2.9 March 7, 2006
* Last changed in libpng 1.2.9 March 9, 2006
* For conditions of distribution and use, see copyright notice in png.h
* Copyright (c) 1998-2006 Glenn Randers-Pehrson
* (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
@@ -551,7 +551,7 @@ void PNGAPI
png_set_expand(png_structp png_ptr)
{
png_debug(1, "in png_set_expand\n");
png_ptr->transformations |= PNG_EXPAND;
png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS);
}
/* GRR 19990627: the following three functions currently are identical
@@ -566,30 +566,47 @@ png_set_expand(png_structp png_ptr)
*
* 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_expand\n");
png_ptr->transformations |= PNG_EXPAND;
png_debug(1, "in png_set_palette_to_rgb\n");
png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS);
}
#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\n");
png_ptr->transformations |= PNG_EXPAND_tRNS;
}
#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_expand\n");
png_ptr->transformations |= PNG_EXPAND;
png_debug(1, "in png_set_gray_1_2_4_to_8\n");
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_expand\n");
png_ptr->transformations |= PNG_EXPAND;
png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS);
}
#endif /* defined(PNG_READ_EXPAND_SUPPORTED) */
@@ -707,23 +724,41 @@ png_init_read_transformations(png_structp png_ptr)
{
if (!(color_type & PNG_COLOR_MASK_COLOR)) /* i.e., GRAY or GRAY_ALPHA */
{
/* expand background chunk. */
/* 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:
@@ -745,7 +780,7 @@ png_init_read_transformations(png_structp png_ptr)
if (png_ptr->transformations & PNG_INVERT_ALPHA)
{
#if defined(PNG_READ_EXPAND_SUPPORTED)
if (!(png_ptr->transformations & PNG_EXPAND))
if (!(png_ptr->transformations & PNG_EXPAND_tRNS))
#endif
{
/* invert the alpha channel (in tRNS) unless the pixels are
@@ -1045,7 +1080,7 @@ png_read_transform_info(png_structp png_ptr, png_infop info_ptr)
{
if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
{
if (png_ptr->num_trans)
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;
@@ -1055,7 +1090,12 @@ png_read_transform_info(png_structp png_ptr, png_infop info_ptr)
else
{
if (png_ptr->num_trans)
info_ptr->color_type |= PNG_COLOR_MASK_ALPHA;
{
if (png_ptr->transformations & PNG_EXPAND_tRNS)
info_ptr->color_type |= PNG_COLOR_MASK_ALPHA;
else
info_ptr->color_type |= PNG_COLOR_MASK_COLOR;
}
if (info_ptr->bit_depth < 8)
info_ptr->bit_depth = 8;
info_ptr->num_trans = 0;
@@ -1201,7 +1241,7 @@ png_do_read_transformations(png_structp png_ptr)
}
else
{
if (png_ptr->num_trans)
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
@@ -3604,8 +3644,8 @@ png_do_expand_palette(png_row_infop row_info, png_bytep row,
}
}
/* If the bit depth < 8, it is expanded to 8. Also, if the
* transparency value is supplied, an alpha channel is built.
/* If the bit depth < 8, it is expanded to 8. Also, if the already
* expanded transparency value is supplied, an alpha channel is built.
*/
void /* PRIVATE */
png_do_expand(png_row_infop row_info, png_bytep row,