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Imported from libpng-1.0.1b.tar

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This commit is contained in:
Glenn Randers-Pehrson
1998-05-02 12:52:25 -05:00
parent 896239be20
commit 1d96361273
29 changed files with 837 additions and 710 deletions
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247
pngwutil.c
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@@ -1,12 +1,12 @@
/* pngwutil.c - utilities to write a PNG file
*
* libpng 1.0.1a
* 1.0.1b
* 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
* April 21, 1998
* May 2, 1998
*/
#define PNG_INTERNAL
@@ -1251,13 +1251,13 @@ png_do_write_interlace(png_row_infop row_info, png_bytep row, int pass)
int shift;
int d;
int value;
png_uint_32 i, istop;
png_uint_32 i;
png_uint_32 row_width = row_info->width;
dp = row;
d = 0;
shift = 7;
istop = row_info->width;
for (i = png_pass_start[pass]; i < istop;
for (i = png_pass_start[pass]; i < row_width;
i += png_pass_inc[pass])
{
sp = row + (png_size_t)(i >> 3);
@@ -1285,13 +1285,13 @@ png_do_write_interlace(png_row_infop row_info, png_bytep row, int pass)
int shift;
int d;
int value;
png_uint_32 i, istop;
png_uint_32 i;
png_uint_32 row_width = row_info->width;
dp = row;
shift = 6;
d = 0;
istop = row_info->width;
for (i = png_pass_start[pass]; i < istop;
for (i = png_pass_start[pass]; i < row_width;
i += png_pass_inc[pass])
{
sp = row + (png_size_t)(i >> 2);
@@ -1318,13 +1318,13 @@ png_do_write_interlace(png_row_infop row_info, png_bytep row, int pass)
int shift;
int d;
int value;
png_uint_32 i, istop;
png_uint_32 i;
png_uint_32 row_width = row_info->width;
dp = row;
shift = 4;
d = 0;
istop = row_info->width;
for (i = png_pass_start[pass]; i < istop;
for (i = png_pass_start[pass]; i < row_width;
i += png_pass_inc[pass])
{
sp = row + (png_size_t)(i >> 1);
@@ -1348,7 +1348,8 @@ png_do_write_interlace(png_row_infop row_info, png_bytep row, int pass)
{
png_bytep sp;
png_bytep dp;
png_uint_32 i, istop;
png_uint_32 i;
png_uint_32 row_width = row_info->width;
png_size_t pixel_bytes;
/* start at the beginning */
@@ -1357,8 +1358,7 @@ png_do_write_interlace(png_row_infop row_info, png_bytep row, int pass)
pixel_bytes = (row_info->pixel_depth >> 3);
/* loop through the row, only looking at the pixels that
matter */
istop = row_info->width;
for (i = png_pass_start[pass]; i < istop;
for (i = png_pass_start[pass]; i < row_width;
i += png_pass_inc[pass])
{
/* find out where the original pixel is */
@@ -1397,6 +1397,10 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info)
png_bytep prev_row, best_row, row_buf;
png_uint_32 mins, bpp;
png_byte filter_to_do = png_ptr->do_filter;
png_uint_32 row_bytes = row_info->rowbytes;
#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
int num_p_filters = (int)png_ptr->num_prev_filters;
#endif
png_debug(1, "in png_write_find_filter\n");
/* find out how many bytes offset each pixel is */
@@ -1427,11 +1431,11 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info)
{
png_bytep rp;
png_uint_32 sum = 0;
png_uint_32 i,istop;
png_uint_32 i;
int j;
int v;
istop = row_info->rowbytes;
for (i = 0, rp = row_buf + 1; i < istop; i++, rp++)
for (i = 0, rp = row_buf + 1; i < row_bytes; i++, rp++)
{
v = *rp;
sum += (v < 128) ? v : 256 - v;
@@ -1445,14 +1449,13 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info)
sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK; /* Gives us some footroom */
/* Reduce the sum if we match any of the previous rows */
istop = (png_uint_32)png_ptr->num_prev_filters;
for (i = 0; i < istop; i++)
for (j = 0; j < num_p_filters; j++)
{
if (png_ptr->prev_filters[i] == PNG_FILTER_VALUE_NONE)
if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_NONE)
{
sumlo = (sumlo * png_ptr->filter_weights[i]) >>
sumlo = (sumlo * png_ptr->filter_weights[j]) >>
PNG_WEIGHT_SHIFT;
sumhi = (sumhi * png_ptr->filter_weights[i]) >>
sumhi = (sumhi * png_ptr->filter_weights[j]) >>
PNG_WEIGHT_SHIFT;
}
}
@@ -1480,14 +1483,14 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info)
/* it's the only filter so no testing is needed */
{
png_bytep rp, lp, dp;
png_uint_32 i,istop;
png_uint_32 i;
int j;
for (i = 0, rp = row_buf + 1, dp = png_ptr->sub_row + 1; i < bpp;
i++, rp++, dp++)
{
*dp = *rp;
}
istop = row_info->rowbytes;
for (lp = row_buf + 1; i < istop;
for (lp = row_buf + 1; i < row_bytes;
i++, rp++, lp++, dp++)
{
*dp = (png_byte)(((int)*rp - (int)*lp) & 0xff);
@@ -1499,7 +1502,8 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info)
{
png_bytep rp, dp, lp;
png_uint_32 sum = 0, lmins = mins;
png_uint_32 i, istop;
png_uint_32 i;
int j;
int v;
#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
@@ -1513,14 +1517,13 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info)
lmlo = lmins & PNG_LOMASK;
lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK;
istop = (png_uint_32)png_ptr->num_prev_filters;
for (i = 0; i < istop; i++)
for (j = 0; j < num_p_filters; j++)
{
if (png_ptr->prev_filters[i] == PNG_FILTER_VALUE_SUB)
if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_SUB)
{
lmlo = (lmlo * png_ptr->inv_filter_weights[i]) >>
lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >>
PNG_WEIGHT_SHIFT;
lmhi = (lmhi * png_ptr->inv_filter_weights[i]) >>
lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >>
PNG_WEIGHT_SHIFT;
}
}
@@ -1562,14 +1565,13 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info)
sumlo = sum & PNG_LOMASK;
sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK;
istop = (png_uint_32)png_ptr->num_prev_filters;
for (i = 0; i < istop; i++)
for (j = 0; j < num_p_filters; j++)
{
if (png_ptr->prev_filters[i] == PNG_FILTER_VALUE_SUB)
if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_SUB)
{
sumlo = (sumlo * png_ptr->inv_filter_weights[i]) >>
sumlo = (sumlo * png_ptr->inv_filter_weights[j]) >>
PNG_WEIGHT_SHIFT;
sumhi = (sumhi * png_ptr->inv_filter_weights[i]) >>
sumhi = (sumhi * png_ptr->inv_filter_weights[j]) >>
PNG_WEIGHT_SHIFT;
}
}
@@ -1597,11 +1599,10 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info)
if (filter_to_do == PNG_FILTER_UP)
{
png_bytep rp, dp, pp;
png_uint_32 i, istop;
png_uint_32 i;
istop = row_info->rowbytes;
for (i = 0, rp = row_buf + 1, dp = png_ptr->up_row + 1,
pp = prev_row + 1; i < istop;
pp = prev_row + 1; i < row_bytes;
i++, rp++, pp++, dp++)
{
*dp = (png_byte)(((int)*rp - (int)*pp) & 0xff);
@@ -1613,7 +1614,8 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info)
{
png_bytep rp, dp, pp;
png_uint_32 sum = 0, lmins = mins;
png_uint_32 i, istop;
png_uint_32 i;
int j;
int v;
@@ -1624,14 +1626,13 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info)
lmlo = lmins & PNG_LOMASK;
lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK;
istop = (png_uint_32)png_ptr->num_prev_filters;
for (i = 0; i < istop; i++)
for (j = 0; j < num_p_filters; j++)
{
if (png_ptr->prev_filters[i] == PNG_FILTER_VALUE_UP)
if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_UP)
{
lmlo = (lmlo * png_ptr->inv_filter_weights[i]) >>
lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >>
PNG_WEIGHT_SHIFT;
lmhi = (lmhi * png_ptr->inv_filter_weights[i]) >>
lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >>
PNG_WEIGHT_SHIFT;
}
}
@@ -1648,12 +1649,10 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info)
}
#endif
istop = row_info->rowbytes;
for (i = 0, rp = row_buf + 1, dp = png_ptr->up_row + 1,
pp = prev_row + 1; i < istop;
i++, rp++, pp++, dp++)
pp = prev_row + 1; i < row_bytes; i++)
{
v = *dp = (png_byte)(((int)*rp - (int)*pp) & 0xff);
v = *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff);
sum += (v < 128) ? v : 256 - v;
@@ -1668,14 +1667,13 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info)
sumlo = sum & PNG_LOMASK;
sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK;
istop = (png_uint_32)png_ptr->num_prev_filters;
for (i = 0; i < istop; i++)
for (j = 0; j < num_p_filters; j++)
{
if (png_ptr->prev_filters[i] == PNG_FILTER_VALUE_UP)
if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_UP)
{
sumlo = (sumlo * png_ptr->filter_weights[i]) >>
sumlo = (sumlo * png_ptr->filter_weights[j]) >>
PNG_WEIGHT_SHIFT;
sumhi = (sumhi * png_ptr->filter_weights[i]) >>
sumhi = (sumhi * png_ptr->filter_weights[j]) >>
PNG_WEIGHT_SHIFT;
}
}
@@ -1703,16 +1701,16 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info)
if (filter_to_do == PNG_FILTER_AVG)
{
png_bytep rp, dp, pp, lp;
png_uint_32 i,istop;
png_uint_32 i;
for (i = 0, rp = row_buf + 1, dp = png_ptr->avg_row + 1,
pp = prev_row + 1; i < bpp; i++, rp++, pp++, dp++)
pp = prev_row + 1; i < bpp; i++)
{
*dp = (png_byte)(((int)*rp - ((int)*pp / 2)) & 0xff);
*dp++ = (png_byte)(((int)*rp++ - ((int)*pp++ / 2)) & 0xff);
}
istop = row_info->rowbytes;
for (lp = row_buf + 1; i < istop; i++, rp++, pp++, lp++, dp++)
for (lp = row_buf + 1; i < row_bytes; i++)
{
*dp = (png_byte)(((int)*rp - (((int)*pp + (int)*lp) / 2)) & 0xff);
*dp++ = (png_byte)(((int)*rp++ - (((int)*pp++ + (int)*lp++) / 2))
& 0xff);
}
best_row = png_ptr->avg_row;
}
@@ -1721,7 +1719,8 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info)
{
png_bytep rp, dp, pp, lp;
png_uint_32 sum = 0, lmins = mins;
png_uint_32 i,istop;
png_uint_32 i;
int j;
int v;
#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
@@ -1731,14 +1730,13 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info)
lmlo = lmins & PNG_LOMASK;
lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK;
istop = (png_uint_32)png_ptr->num_prev_filters;
for (i = 0; i < istop; i++)
for (j = 0; j < num_p_filters; j++)
{
if (png_ptr->prev_filters[i] == PNG_FILTER_VALUE_AVG)
if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_AVG)
{
lmlo = (lmlo * png_ptr->inv_filter_weights[i]) >>
lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >>
PNG_WEIGHT_SHIFT;
lmhi = (lmhi * png_ptr->inv_filter_weights[i]) >>
lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >>
PNG_WEIGHT_SHIFT;
}
}
@@ -1756,16 +1754,16 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info)
#endif
for (i = 0, rp = row_buf + 1, dp = png_ptr->avg_row + 1,
pp = prev_row + 1; i < bpp; i++, rp++, pp++, dp++)
pp = prev_row + 1; i < bpp; i++)
{
v = *dp = (png_byte)(((int)*rp - ((int)*pp / 2)) & 0xff);
v = *dp++ = (png_byte)(((int)*rp++ - ((int)*pp++ / 2)) & 0xff);
sum += (v < 128) ? v : 256 - v;
}
istop = row_info->rowbytes;
for (lp = row_buf + 1; i < istop; i++, rp++, pp++, lp++, dp++)
for (lp = row_buf + 1; i < row_bytes; i++)
{
v = *dp = (png_byte)(((int)*rp - (((int)*pp + (int)*lp) / 2)) & 0xff);
v = *dp++ =
(png_byte)(((int)*rp++ - (((int)*pp++ + (int)*lp++) / 2)) & 0xff);
sum += (v < 128) ? v : 256 - v;
@@ -1780,14 +1778,13 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info)
sumlo = sum & PNG_LOMASK;
sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK;
istop = png_ptr->num_prev_filters;
for (i = 0; i < istop; i++)
for (j = 0; j < num_p_filters; j++)
{
if (png_ptr->prev_filters[i] == PNG_FILTER_VALUE_NONE)
if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_NONE)
{
sumlo = (sumlo * png_ptr->filter_weights[i]) >>
sumlo = (sumlo * png_ptr->filter_weights[j]) >>
PNG_WEIGHT_SHIFT;
sumhi = (sumhi * png_ptr->filter_weights[i]) >>
sumhi = (sumhi * png_ptr->filter_weights[j]) >>
PNG_WEIGHT_SHIFT;
}
}
@@ -1815,38 +1812,37 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info)
if (filter_to_do == PNG_FILTER_PAETH)
{
png_bytep rp, dp, pp, cp, lp;
png_uint_32 i, istop;
png_uint_32 i;
for (i = 0, rp = row_buf + 1, dp = png_ptr->paeth_row + 1,
pp = prev_row + 1; i < bpp; i++, rp++, pp++, dp++)
pp = prev_row + 1; i < bpp; i++)
{
*dp = (png_byte)(((int)*rp - (int)*pp) & 0xff);
*dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff);
}
istop = row_info->rowbytes;
for (lp = row_buf + 1, cp = prev_row + 1; i < istop;
i++, rp++, pp++, lp++, dp++, cp++)
for (lp = row_buf + 1, cp = prev_row + 1; i < row_bytes; i++)
{
int a, b, c, pa, pb, pc, p;
b = *pp;
c = *cp;
a = *lp;
b = *pp++;
c = *cp++;
a = *lp++;
p = a + b - c;
p = b - c;
pc = a - c;
#ifdef PNG_USE_ABS
pa = abs(p - a);
pb = abs(p - b);
pc = abs(p - c);
pa = abs(p);
pb = abs(pc);
pc = abs(p + pc);
#else
pa = p > a ? p - a : a - p;
pb = p > b ? p - b : b - p;
pc = p > c ? p - c : c - p;
pa = p < 0 ? -p : p;
pb = pc < 0 ? -pc : pc;
pc = (p + pc) < 0 ? -(p + pc) : p + pc;
#endif
p = (pa <= pb && pa <=pc) ? a : (pb <= pc) ? b : c;
*dp = (png_byte)(((int)*rp - p) & 0xff);
*dp++ = (png_byte)(((int)*rp++ - p) & 0xff);
}
best_row = png_ptr->paeth_row;
}
@@ -1855,7 +1851,8 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info)
{
png_bytep rp, dp, pp, cp, lp;
png_uint_32 sum = 0, lmins = mins;
png_uint_32 i, istop;
png_uint_32 i;
int j;
int v;
#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
@@ -1865,14 +1862,13 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info)
lmlo = lmins & PNG_LOMASK;
lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK;
istop = png_ptr->num_prev_filters;
for (i = 0; i < istop; i++)
for (j = 0; j < num_p_filters; j++)
{
if (png_ptr->prev_filters[i] == PNG_FILTER_VALUE_PAETH)
if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_PAETH)
{
lmlo = (lmlo * png_ptr->inv_filter_weights[i]) >>
lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >>
PNG_WEIGHT_SHIFT;
lmhi = (lmhi * png_ptr->inv_filter_weights[i]) >>
lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >>
PNG_WEIGHT_SHIFT;
}
}
@@ -1890,38 +1886,36 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info)
#endif
for (i = 0, rp = row_buf + 1, dp = png_ptr->paeth_row + 1,
pp = prev_row + 1; i < bpp; i++, rp++, pp++, dp++)
pp = prev_row + 1; i < bpp; i++)
{
v = *dp = (png_byte)(((int)*rp - (int)*pp) & 0xff);
v = *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff);
sum += (v < 128) ? v : 256 - v;
}
istop = row_info->rowbytes;
for (lp = row_buf + 1, cp = prev_row + 1; i < istop;
i++, rp++, pp++, lp++, dp++, cp++)
for (lp = row_buf + 1, cp = prev_row + 1; i < row_bytes; i++)
{
int a, b, c, pa, pb, pc, p;
b = *pp;
c = *cp;
a = *lp;
p = a + b - c;
b = *pp++;
c = *cp++;
a = *lp++;
#ifndef PNG_SLOW_PAETH
p = b - c;
pc = a - c;
#ifdef PNG_USE_ABS
pa = abs(p - a);
pb = abs(p - b);
pc = abs(p - c);
pa = abs(p);
pb = abs(pc);
pc = abs(p + pc);
#else
pa = p > a ? p - a : a - p;
pb = p > b ? p - b : b - p;
pc = p > c ? p - c : c - p;
pa = p < 0 ? -p : p;
pb = pc < 0 ? -pc : pc;
pc = (p + pc) < 0 ? -(p + pc) : p + pc;
#endif
p = (pa <= pb && pa <=pc) ? a : (pb <= pc) ? b : c;
#else /* PNG_SLOW_PAETH */
p = a + b - c;
pa = abs(p - a);
pb = abs(p - b);
pc = abs(p - c);
@@ -1933,7 +1927,7 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info)
p = c;
#endif /* PNG_SLOW_PAETH */
v = *dp = (png_byte)(((int)*rp - p) & 0xff);
v = *dp++ = (png_byte)(((int)*rp++ - p) & 0xff);
sum += (v < 128) ? v : 256 - v;
@@ -1948,14 +1942,13 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info)
sumlo = sum & PNG_LOMASK;
sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK;
istop = png_ptr->num_prev_filters;
for (i = 0; i < istop; i++)
for (j = 0; j < num_p_filters; j++)
{
if (png_ptr->prev_filters[i] == PNG_FILTER_VALUE_PAETH)
if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_PAETH)
{
sumlo = (sumlo * png_ptr->filter_weights[i]) >>
sumlo = (sumlo * png_ptr->filter_weights[j]) >>
PNG_WEIGHT_SHIFT;
sumhi = (sumhi * png_ptr->filter_weights[i]) >>
sumhi = (sumhi * png_ptr->filter_weights[j]) >>
PNG_WEIGHT_SHIFT;
}
}
@@ -1986,14 +1979,12 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info)
/* Save the type of filter we picked this time for future calculations */
if (png_ptr->num_prev_filters > 0)
{
int i, istop;
istop = (int)png_ptr->num_prev_filters;
for (i = 1; i < istop; i++)
int j;
for (j = 1; j < num_p_filters; j++)
{
png_ptr->prev_filters[i] = png_ptr->prev_filters[i - 1];
png_ptr->prev_filters[j] = png_ptr->prev_filters[j - 1];
}
png_ptr->prev_filters[i] = best_row[0];
png_ptr->prev_filters[j] = best_row[0];
}
#endif
}