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Imported from libpng-1.0.1c.tar

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This commit is contained in:
Glenn Randers-Pehrson
1998-05-09 10:02:29 -05:00
parent 1d96361273
commit d0dce40075
30 changed files with 373 additions and 200 deletions
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68
pngwtran.c
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@@ -1,12 +1,12 @@
/* pngwtran.c - transforms the data in a row for PNG writers
*
* 1.0.1b
* 1.0.1c
* 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
* May 2, 1998
* May 9, 1998
*/
#define PNG_INTERNAL
@@ -218,9 +218,8 @@ png_do_shift(png_row_infop row_info, png_bytep row, png_color_8p bit_depth)
row_info->color_type != PNG_COLOR_TYPE_PALETTE)
{
int shift_start[4], shift_dec[4];
int channels;
int channels = 0;
channels = 0;
if (row_info->color_type & PNG_COLOR_MASK_COLOR)
{
shift_start[channels] = row_info->bit_depth - bit_depth->red;
@@ -281,26 +280,23 @@ png_do_shift(png_row_infop row_info, png_bytep row, png_color_8p bit_depth)
{
png_bytep bp = row;
png_uint_32 i;
png_uint_32 row_width = row_info->width;
png_uint_32 istop = channels * row_info->width;
for (i = 0; i < row_width; i++)
for (i = 0; i < istop; i++, bp++)
{
int c;
for (c = 0; c < channels; c++, bp++)
png_uint_16 v;
int j;
int c = (int)(i%channels);
v = *bp;
*bp = 0;
for (j = shift_start[c]; j > -shift_dec[c]; j -= shift_dec[c])
{
png_uint_16 v;
int j;
v = *bp;
*bp = 0;
for (j = shift_start[c]; j > -shift_dec[c]; j -= shift_dec[c])
{
if (j > 0)
*bp |= (png_byte)((v << j) & 0xff);
else
*bp |= (png_byte)((v >> (-j)) & 0xff);
}
if (j > 0)
*bp |= (png_byte)((v << j) & 0xff);
else
*bp |= (png_byte)((v >> (-j)) & 0xff);
}
}
}
@@ -308,29 +304,25 @@ png_do_shift(png_row_infop row_info, png_bytep row, png_color_8p bit_depth)
{
png_bytep bp;
png_uint_32 i;
png_uint_32 row_width = row_info->width;
png_uint_32 istop = channels * row_info->width;
for (bp = row, i = 0; i < row_width; i++)
for (bp = row, i = 0; i < istop; i++)
{
int c;
int c = (int)(i%channels);
png_uint_16 value, v;
int j;
for (c = 0; c < channels; c++, bp += 2)
v = ((png_uint_16)(*bp) << 8) + *(bp + 1);
value = 0;
for (j = shift_start[c]; j > -shift_dec[c]; j -= shift_dec[c])
{
png_uint_16 value, v;
int j;
v = ((png_uint_16)(*bp) << 8) + *(bp + 1);
value = 0;
for (j = shift_start[c]; j > -shift_dec[c]; j -= shift_dec[c])
{
if (j > 0)
value |= (png_uint_16)((v << j) & (png_uint_16)0xffff);
else
value |= (png_uint_16)((v >> (-j)) & (png_uint_16)0xffff);
}
*bp = (png_byte)(value >> 8);
*(bp + 1) = (png_byte)(value & 0xff);
if (j > 0)
value |= (png_uint_16)((v << j) & (png_uint_16)0xffff);
else
value |= (png_uint_16)((v >> (-j)) & (png_uint_16)0xffff);
}
*bp++ = (png_byte)(value >> 8);
*bp++ = (png_byte)(value & 0xff);
}
}
}