/* pngwtran.c - transforms the data in a row for PNG writers
*
- * libpng 1.0.3 - January 14, 1999
- * 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, 1999 Glenn Randers-Pehrson
+ * Last changed in libpng 1.6.0 [February 14, 2013]
+ * Copyright (c) 1998-2013 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
*/
-#define PNG_INTERNAL
-#include "png.h"
+#include "pngpriv.h"
+
+#ifdef PNG_WRITE_SUPPORTED
+#ifdef PNG_WRITE_TRANSFORMS_SUPPORTED
/* Transform the data according to the user's wishes. The order of
* transformations is significant.
*/
-void
-png_do_write_transformations(png_structp png_ptr)
+void /* PRIVATE */
+png_do_write_transformations(png_structrp png_ptr, png_row_infop row_info)
{
- png_debug(1, "in png_do_write_transformations\n");
+ png_debug(1, "in png_do_write_transformations");
+
+ if (png_ptr == NULL)
+ return;
-#if defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
+#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
if (png_ptr->transformations & PNG_USER_TRANSFORM)
- if(png_ptr->write_user_transform_fn != NULL)
- (*(png_ptr->write_user_transform_fn)) /* user write transform function */
- (png_ptr, /* png_ptr */
- &(png_ptr->row_info), /* row_info: */
- /* png_uint_32 width; width of row */
- /* png_uint_32 rowbytes; number of bytes in row */
- /* png_byte color_type; color type of pixels */
- /* png_byte bit_depth; bit depth of samples */
- /* png_byte channels; number of channels (1-4) */
- /* png_byte pixel_depth; bits per pixel (depth*channels) */
- png_ptr->row_buf + 1); /* start of pixel data for row */
+ if (png_ptr->write_user_transform_fn != NULL)
+ (*(png_ptr->write_user_transform_fn)) /* User write transform
+ function */
+ (png_ptr, /* png_ptr */
+ row_info, /* row_info: */
+ /* png_uint_32 width; width of row */
+ /* png_size_t rowbytes; number of bytes in row */
+ /* png_byte color_type; color type of pixels */
+ /* png_byte bit_depth; bit depth of samples */
+ /* png_byte channels; number of channels (1-4) */
+ /* png_byte pixel_depth; bits per pixel (depth*channels) */
+ png_ptr->row_buf + 1); /* start of pixel data for row */
#endif
-#if defined(PNG_WRITE_FILLER_SUPPORTED)
+
+#ifdef PNG_WRITE_FILLER_SUPPORTED
if (png_ptr->transformations & PNG_FILLER)
- png_do_strip_filler(&(png_ptr->row_info), png_ptr->row_buf + 1,
- png_ptr->flags);
+ png_do_strip_channel(row_info, png_ptr->row_buf + 1,
+ !(png_ptr->flags & PNG_FLAG_FILLER_AFTER));
#endif
-#if defined(PNG_WRITE_PACKSWAP_SUPPORTED)
+
+#ifdef PNG_WRITE_PACKSWAP_SUPPORTED
if (png_ptr->transformations & PNG_PACKSWAP)
- png_do_packswap(&(png_ptr->row_info), png_ptr->row_buf + 1);
+ png_do_packswap(row_info, png_ptr->row_buf + 1);
#endif
-#if defined(PNG_WRITE_PACK_SUPPORTED)
+
+#ifdef PNG_WRITE_PACK_SUPPORTED
if (png_ptr->transformations & PNG_PACK)
- png_do_pack(&(png_ptr->row_info), png_ptr->row_buf + 1,
- (png_uint_32)png_ptr->bit_depth);
+ png_do_pack(row_info, png_ptr->row_buf + 1,
+ (png_uint_32)png_ptr->bit_depth);
#endif
-#if defined(PNG_WRITE_SWAP_SUPPORTED)
+
+#ifdef PNG_WRITE_SWAP_SUPPORTED
if (png_ptr->transformations & PNG_SWAP_BYTES)
- png_do_swap(&(png_ptr->row_info), png_ptr->row_buf + 1);
+ png_do_swap(row_info, png_ptr->row_buf + 1);
#endif
-#if defined(PNG_WRITE_SHIFT_SUPPORTED)
+
+#ifdef PNG_WRITE_SHIFT_SUPPORTED
if (png_ptr->transformations & PNG_SHIFT)
- png_do_shift(&(png_ptr->row_info), png_ptr->row_buf + 1,
- &(png_ptr->shift));
-#endif
-#if defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
- if (png_ptr->transformations & PNG_INVERT_ALPHA)
- png_do_write_invert_alpha(&(png_ptr->row_info), png_ptr->row_buf + 1);
+ png_do_shift(row_info, png_ptr->row_buf + 1,
+ &(png_ptr->shift));
#endif
-#if defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
+
+#ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED
if (png_ptr->transformations & PNG_SWAP_ALPHA)
- png_do_write_swap_alpha(&(png_ptr->row_info), png_ptr->row_buf + 1);
+ png_do_write_swap_alpha(row_info, png_ptr->row_buf + 1);
+#endif
+
+#ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED
+ if (png_ptr->transformations & PNG_INVERT_ALPHA)
+ png_do_write_invert_alpha(row_info, png_ptr->row_buf + 1);
#endif
-#if defined(PNG_WRITE_BGR_SUPPORTED)
+
+#ifdef PNG_WRITE_BGR_SUPPORTED
if (png_ptr->transformations & PNG_BGR)
- png_do_bgr(&(png_ptr->row_info), png_ptr->row_buf + 1);
+ png_do_bgr(row_info, png_ptr->row_buf + 1);
#endif
-#if defined(PNG_WRITE_INVERT_SUPPORTED)
+
+#ifdef PNG_WRITE_INVERT_SUPPORTED
if (png_ptr->transformations & PNG_INVERT_MONO)
- png_do_invert(&(png_ptr->row_info), png_ptr->row_buf + 1);
+ png_do_invert(row_info, png_ptr->row_buf + 1);
#endif
}
-#if defined(PNG_WRITE_PACK_SUPPORTED)
+#ifdef PNG_WRITE_PACK_SUPPORTED
/* Pack pixels into bytes. Pass the true bit depth in bit_depth. The
* row_info bit depth should be 8 (one pixel per byte). The channels
* should be 1 (this only happens on grayscale and paletted images).
*/
-void
+void /* PRIVATE */
png_do_pack(png_row_infop row_info, png_bytep row, png_uint_32 bit_depth)
{
- png_debug(1, "in png_do_pack\n");
+ png_debug(1, "in png_do_pack");
+
if (row_info->bit_depth == 8 &&
-#if defined(PNG_USELESS_TESTS_SUPPORTED)
- row != NULL && row_info != NULL &&
-#endif
row_info->channels == 1)
{
switch ((int)bit_depth)
{
if (*sp != 0)
v |= mask;
+
sp++;
+
if (mask > 1)
mask >>= 1;
+
else
{
mask = 0x80;
v = 0;
}
}
+
if (mask != 0x80)
*dp = (png_byte)v;
+
break;
}
+
case 2:
{
png_bytep sp, dp;
dp = row;
shift = 6;
v = 0;
+
for (i = 0; i < row_width; i++)
{
png_byte value;
- value = (png_byte)(*sp & 0x3);
+ value = (png_byte)(*sp & 0x03);
v |= (value << shift);
+
if (shift == 0)
{
shift = 6;
dp++;
v = 0;
}
+
else
shift -= 2;
+
sp++;
}
+
if (shift != 6)
*dp = (png_byte)v;
+
break;
}
+
case 4:
{
png_bytep sp, dp;
dp = row;
shift = 4;
v = 0;
+
for (i = 0; i < row_width; i++)
{
png_byte value;
- value = (png_byte)(*sp & 0xf);
+ value = (png_byte)(*sp & 0x0f);
v |= (value << shift);
if (shift == 0)
dp++;
v = 0;
}
+
else
shift -= 4;
sp++;
}
+
if (shift != 4)
*dp = (png_byte)v;
+
break;
}
+
+ default:
+ break;
}
+
row_info->bit_depth = (png_byte)bit_depth;
row_info->pixel_depth = (png_byte)(bit_depth * row_info->channels);
- row_info->rowbytes =
- ((row_info->width * row_info->pixel_depth + 7) >> 3);
+ row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth,
+ row_info->width);
}
}
#endif
-#if defined(PNG_WRITE_SHIFT_SUPPORTED)
+#ifdef PNG_WRITE_SHIFT_SUPPORTED
/* Shift pixel values to take advantage of whole range. Pass the
* true number of bits in bit_depth. The row should be packed
* according to row_info->bit_depth. Thus, if you had a row of
* would pass 3 as bit_depth, and this routine would translate the
* data to 0 to 15.
*/
-void
-png_do_shift(png_row_infop row_info, png_bytep row, png_color_8p bit_depth)
+void /* PRIVATE */
+png_do_shift(png_row_infop row_info, png_bytep row,
+ png_const_color_8p bit_depth)
{
- png_debug(1, "in png_do_shift\n");
-#if defined(PNG_USELESS_TESTS_SUPPORTED)
- if (row != NULL && row_info != NULL &&
-#else
- if (
-#endif
- row_info->color_type != PNG_COLOR_TYPE_PALETTE)
+ png_debug(1, "in png_do_shift");
+
+ if (row_info->color_type != PNG_COLOR_TYPE_PALETTE)
{
int shift_start[4], shift_dec[4];
int channels = 0;
shift_start[channels] = row_info->bit_depth - bit_depth->red;
shift_dec[channels] = bit_depth->red;
channels++;
+
shift_start[channels] = row_info->bit_depth - bit_depth->green;
shift_dec[channels] = bit_depth->green;
channels++;
+
shift_start[channels] = row_info->bit_depth - bit_depth->blue;
shift_dec[channels] = bit_depth->blue;
channels++;
}
+
else
{
shift_start[channels] = row_info->bit_depth - bit_depth->gray;
shift_dec[channels] = bit_depth->gray;
channels++;
}
+
if (row_info->color_type & PNG_COLOR_MASK_ALPHA)
{
shift_start[channels] = row_info->bit_depth - bit_depth->alpha;
channels++;
}
- /* with low row depths, could only be grayscale, so one channel */
+ /* With low row depths, could only be grayscale, so one channel */
if (row_info->bit_depth < 8)
{
png_bytep bp = row;
- png_uint_32 i;
- png_byte mask;
- png_uint_32 row_bytes = row_info->rowbytes;
+ png_size_t i;
+ unsigned int mask;
+ png_size_t row_bytes = row_info->rowbytes;
if (bit_depth->gray == 1 && row_info->bit_depth == 2)
mask = 0x55;
+
else if (row_info->bit_depth == 4 && bit_depth->gray == 3)
mask = 0x11;
+
else
mask = 0xff;
for (i = 0; i < row_bytes; i++, bp++)
{
- png_uint_16 v;
int j;
+ unsigned int v, out;
v = *bp;
- *bp = 0;
+ out = 0;
+
for (j = shift_start[0]; j > -shift_dec[0]; j -= shift_dec[0])
{
if (j > 0)
- *bp |= (png_byte)((v << j) & 0xff);
+ out |= v << j;
+
else
- *bp |= (png_byte)((v >> (-j)) & mask);
+ out |= (v >> (-j)) & mask;
}
+
+ *bp = (png_byte)(out & 0xff);
}
}
+
else if (row_info->bit_depth == 8)
{
png_bytep bp = row;
for (i = 0; i < istop; i++, bp++)
{
- png_uint_16 v;
+ const unsigned int c = i%channels;
int j;
- int c = (int)(i%channels);
+ unsigned int v, out;
v = *bp;
- *bp = 0;
+ out = 0;
+
for (j = shift_start[c]; j > -shift_dec[c]; j -= shift_dec[c])
{
if (j > 0)
- *bp |= (png_byte)((v << j) & 0xff);
+ out |= v << j;
+
else
- *bp |= (png_byte)((v >> (-j)) & 0xff);
+ out |= v >> (-j);
}
+
+ *bp = (png_byte)(out & 0xff);
}
}
+
else
{
png_bytep bp;
for (bp = row, i = 0; i < istop; i++)
{
- int c = (int)(i%channels);
- png_uint_16 value, v;
+ const unsigned int c = i%channels;
int j;
+ unsigned int value, v;
- v = ((png_uint_16)(*bp) << 8) + *(bp + 1);
+ v = png_get_uint_16(bp);
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);
+ value |= v << j;
+
else
- value |= (png_uint_16)((v >> (-j)) & (png_uint_16)0xffff);
+ value |= v >> (-j);
}
- *bp++ = (png_byte)(value >> 8);
+ *bp++ = (png_byte)((value >> 8) & 0xff);
*bp++ = (png_byte)(value & 0xff);
}
}
}
#endif
-#if defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
-void
+#ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED
+void /* PRIVATE */
png_do_write_swap_alpha(png_row_infop row_info, png_bytep row)
{
- png_debug(1, "in png_do_write_swap_alpha\n");
-#if defined(PNG_USELESS_TESTS_SUPPORTED)
- if (row != NULL && row_info != NULL)
-#endif
+ png_debug(1, "in png_do_write_swap_alpha");
+
{
if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
{
- /* This converts from ARGB to RGBA */
if (row_info->bit_depth == 8)
{
+ /* This converts from ARGB to RGBA */
png_bytep sp, dp;
png_uint_32 i;
png_uint_32 row_width = row_info->width;
+
for (i = 0, sp = dp = row; i < row_width; i++)
{
png_byte save = *(sp++);
*(dp++) = save;
}
}
- /* This converts from AARRGGBB to RRGGBBAA */
+
+#ifdef PNG_WRITE_16BIT_SUPPORTED
else
{
+ /* This converts from AARRGGBB to RRGGBBAA */
png_bytep sp, dp;
png_uint_32 i;
png_uint_32 row_width = row_info->width;
*(dp++) = save[1];
}
}
+#endif /* PNG_WRITE_16BIT_SUPPORTED */
}
+
else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
{
- /* This converts from AG to GA */
if (row_info->bit_depth == 8)
{
+ /* This converts from AG to GA */
png_bytep sp, dp;
png_uint_32 i;
png_uint_32 row_width = row_info->width;
*(dp++) = save;
}
}
- /* This converts from AAGG to GGAA */
+
+#ifdef PNG_WRITE_16BIT_SUPPORTED
else
{
+ /* This converts from AAGG to GGAA */
png_bytep sp, dp;
png_uint_32 i;
png_uint_32 row_width = row_info->width;
*(dp++) = save[1];
}
}
+#endif /* PNG_WRITE_16BIT_SUPPORTED */
}
}
}
#endif
-#if defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
-void
+#ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED
+void /* PRIVATE */
png_do_write_invert_alpha(png_row_infop row_info, png_bytep row)
{
- png_debug(1, "in png_do_write_invert_alpha\n");
-#if defined(PNG_USELESS_TESTS_SUPPORTED)
- if (row != NULL && row_info != NULL)
-#endif
+ png_debug(1, "in png_do_write_invert_alpha");
+
{
if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
{
- /* This inverts the alpha channel in RGBA */
if (row_info->bit_depth == 8)
{
+ /* This inverts the alpha channel in RGBA */
png_bytep sp, dp;
png_uint_32 i;
png_uint_32 row_width = row_info->width;
+
for (i = 0, sp = dp = row; i < row_width; i++)
{
+ /* Does nothing
*(dp++) = *(sp++);
*(dp++) = *(sp++);
*(dp++) = *(sp++);
- *(dp++) = 255 - *(sp++);
+ */
+ sp+=3; dp = sp;
+ *(dp++) = (png_byte)(255 - *(sp++));
}
}
- /* This inverts the alpha channel in RRGGBBAA */
+
+#ifdef PNG_WRITE_16BIT_SUPPORTED
else
{
+ /* This inverts the alpha channel in RRGGBBAA */
png_bytep sp, dp;
png_uint_32 i;
png_uint_32 row_width = row_info->width;
for (i = 0, sp = dp = row; i < row_width; i++)
{
+ /* Does nothing
*(dp++) = *(sp++);
*(dp++) = *(sp++);
*(dp++) = *(sp++);
*(dp++) = *(sp++);
*(dp++) = *(sp++);
*(dp++) = *(sp++);
- *(dp++) = 255 - *(sp++);
- *(dp++) = 255 - *(sp++);
+ */
+ sp+=6; dp = sp;
+ *(dp++) = (png_byte)(255 - *(sp++));
+ *(dp++) = (png_byte)(255 - *(sp++));
}
}
+#endif /* PNG_WRITE_16BIT_SUPPORTED */
}
+
else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
{
- /* This inverts the alpha channel in GA */
if (row_info->bit_depth == 8)
{
+ /* This inverts the alpha channel in GA */
png_bytep sp, dp;
png_uint_32 i;
png_uint_32 row_width = row_info->width;
for (i = 0, sp = dp = row; i < row_width; i++)
{
*(dp++) = *(sp++);
- *(dp++) = 255 - *(sp++);
+ *(dp++) = (png_byte)(255 - *(sp++));
}
}
- /* This inverts the alpha channel in GGAA */
+
+#ifdef PNG_WRITE_16BIT_SUPPORTED
else
{
+ /* This inverts the alpha channel in GGAA */
png_bytep sp, dp;
png_uint_32 i;
png_uint_32 row_width = row_info->width;
for (i = 0, sp = dp = row; i < row_width; i++)
{
+ /* Does nothing
*(dp++) = *(sp++);
*(dp++) = *(sp++);
- *(dp++) = 255 - *(sp++);
- *(dp++) = 255 - *(sp++);
+ */
+ sp+=2; dp = sp;
+ *(dp++) = (png_byte)(255 - *(sp++));
+ *(dp++) = (png_byte)(255 - *(sp++));
}
}
+#endif /* PNG_WRITE_16BIT_SUPPORTED */
}
}
}
#endif
+#endif /* PNG_WRITE_TRANSFORMS_SUPPORTED */
+
+#ifdef PNG_MNG_FEATURES_SUPPORTED
+/* Undoes intrapixel differencing */
+void /* PRIVATE */
+png_do_write_intrapixel(png_row_infop row_info, png_bytep row)
+{
+ png_debug(1, "in png_do_write_intrapixel");
+
+ if ((row_info->color_type & PNG_COLOR_MASK_COLOR))
+ {
+ int bytes_per_pixel;
+ png_uint_32 row_width = row_info->width;
+ if (row_info->bit_depth == 8)
+ {
+ png_bytep rp;
+ png_uint_32 i;
+
+ if (row_info->color_type == PNG_COLOR_TYPE_RGB)
+ bytes_per_pixel = 3;
+
+ else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+ bytes_per_pixel = 4;
+
+ else
+ return;
+
+ for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel)
+ {
+ *(rp) = (png_byte)((*rp - *(rp + 1)) & 0xff);
+ *(rp + 2) = (png_byte)((*(rp + 2) - *(rp + 1)) & 0xff);
+ }
+ }
+
+#ifdef PNG_WRITE_16BIT_SUPPORTED
+ else if (row_info->bit_depth == 16)
+ {
+ png_bytep rp;
+ png_uint_32 i;
+
+ if (row_info->color_type == PNG_COLOR_TYPE_RGB)
+ bytes_per_pixel = 6;
+
+ else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+ bytes_per_pixel = 8;
+
+ else
+ return;
+
+ for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel)
+ {
+ png_uint_32 s0 = (*(rp ) << 8) | *(rp + 1);
+ png_uint_32 s1 = (*(rp + 2) << 8) | *(rp + 3);
+ png_uint_32 s2 = (*(rp + 4) << 8) | *(rp + 5);
+ png_uint_32 red = (png_uint_32)((s0 - s1) & 0xffffL);
+ png_uint_32 blue = (png_uint_32)((s2 - s1) & 0xffffL);
+ *(rp ) = (png_byte)((red >> 8) & 0xff);
+ *(rp + 1) = (png_byte)(red & 0xff);
+ *(rp + 4) = (png_byte)((blue >> 8) & 0xff);
+ *(rp + 5) = (png_byte)(blue & 0xff);
+ }
+ }
+#endif /* PNG_WRITE_16BIT_SUPPORTED */
+ }
+}
+#endif /* PNG_MNG_FEATURES_SUPPORTED */
+#endif /* PNG_WRITE_SUPPORTED */