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[libpng17] Bookkeeping: Moved functions around (no changes). Moved transform

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function definitions before the place where they are called so that
they can be masde static. Move the intrapixel functions and the
grayscale palette builder out of the png?tran.c files. The latter
isn't a transform function and is no longer used internally, and the
former MNG specific functions are better placed in pngread/pngwrite.c
This commit is contained in:
John Bowler
2013-12-13 23:50:30 -06:00
committed by Glenn Randers-Pehrson
parent 5a1b8d106d
commit d45a632529
9 changed files with 553 additions and 548 deletions
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65
pngwrite.c
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@@ -613,6 +613,71 @@ png_write_image(png_structrp png_ptr, png_bytepp image)
}
}
#ifdef PNG_MNG_FEATURES_SUPPORTED
/* Performs intrapixel differencing */
static void
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 */
/* Called by user to write a row of image data */
void PNGAPI
png_write_row(png_structrp png_ptr, png_const_bytep row)