Imported from libpng-1.0.1c.tar
diff --git a/pngwtran.c b/pngwtran.c
index c6a4201..fc1ba7c 100644
--- a/pngwtran.c
+++ b/pngwtran.c
@@ -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 @@
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_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_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);
}
}
}