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Imported from libpng-1.4.0beta30.tar

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This commit is contained in:
Glenn Randers-Pehrson
2008-08-14 13:44:49 -05:00
parent e0784c72f4
commit 1916f6ae42
63 changed files with 279 additions and 146 deletions
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85
pngrtran.c
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@@ -1,7 +1,7 @@
/* pngrtran.c - transforms the data in a row for PNG readers
*
* Last changed in libpng 1.4.0 [August 9, 2008]
* Last changed in libpng 1.4.0 [August 14, 2008]
* For conditions of distribution and use, see copyright notice in png.h
* Copyright (c) 1998-2008 Glenn Randers-Pehrson
* (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
@@ -1442,6 +1442,11 @@ From Andreas Dilger e-mail to png-implement, 26 March 1998:
(png_uint_32)png_ptr->filler, png_ptr->flags);
#endif
#if defined(PNG_READ_PREMULTIPLY_ALPHA_SUPPORTED)
if (png_ptr->transformations & PNG_PREMULTIPLY_ALPHA)
png_do_read_premultiply_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);
@@ -1915,6 +1920,84 @@ png_do_read_invert_alpha(png_row_infop row_info, png_bytep row)
}
#endif
#if defined(PNG_READ_PREMULTIPLY_ALPHA_SUPPORTED)
void /* PRIVATE */
png_do_read_premultiply_alpha(png_row_infop row_info, png_bytep row)
{
png_debug(1, "in png_do_read_premultiply_alpha\n");
{
png_uint_32 row_width = row_info->width;
if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
{
/* This premultiplies the pixels with the alpha channel in RGBA */
if (row_info->bit_depth == 8)
{
png_bytep sp = row + row_info->rowbytes;
png_bytep dp = sp;
png_uint_16 a = 0;
png_uint_32 i;
for (i = 0; i < row_width; i++)
{
a = *(--sp); --dp;
*(--dp) = (*(--sp) * a) / 255;
*(--dp) = (*(--sp) * a) / 255;
*(--dp) = (*(--sp) * a) / 255;
}
}
/* This premultiplies the pixels with the alpha channel in RRGGBBAA */
else
{
png_uint_16p sp = (png_uint_16p)(row + row_info->rowbytes);
png_uint_16p dp = sp;
png_uint_32 a = 0;
png_uint_32 i;
for (i = 0; i < row_width; i++)
{
a = *(--sp); --dp;
*(--dp) = (png_uint_16) ((*(--sp) * a) / 65535);
*(--dp) = (png_uint_16) ((*(--sp) * a) / 65535);
*(--dp) = (png_uint_16) ((*(--sp) * a) / 65535);
}
}
}
else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
{
/* This premultiplies the pixels with the alpha channel in GA */
if (row_info->bit_depth == 8)
{
png_bytep sp = row + row_info->rowbytes;
png_bytep dp = sp;
png_uint_16 a = 0;
png_uint_32 i;
for (i = 0; i < row_width; i++)
{
a = *(--sp); --dp;
*(--dp) = (*(--sp) * a) / 255;
}
}
/* This premultiplies the pixels with the alpha channel in GGAA */
else
{
png_uint_16p sp = (png_uint_16p) (row + row_info->rowbytes);
png_uint_16p dp = sp;
png_uint_32 a = 0;
png_uint_32 i;
for (i = 0; i < row_width; i++)
{
a = *(--sp); --dp;
*(--dp) = (png_uint_16) ((*(--sp) * a) / 65535);
}
}
}
}
}
#endif
#if defined(PNG_READ_FILLER_SUPPORTED)
/* Add filler channel if we have RGB color */
void /* PRIVATE */