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Merge branch 'stb_image_write_png_filters_fix' of https://github.com/kosua20/stb into working

master
Sean Barrett 2018-02-11 11:09:07 -08:00
parent 6382814b8c 34f087ce4c
commit 2886b67f7f
1 changed files with 7 additions and 6 deletions
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13
stb_image_write.h
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@ -988,13 +988,14 @@ static void stbiw__encode_png_line(unsigned char *pixels, int stride_bytes, int
int i;
int type = mymap[filter_type];
unsigned char *z = pixels + stride_bytes * (stbi__flip_vertically_on_write ? height-1-y : y);
int signed_stride = stbi__flip_vertically_on_write ? -stride_bytes : stride_bytes;
for (i = 0; i < n; ++i) {
switch (type) {
case 0: line_buffer[i] = z[i]; break;
case 1: line_buffer[i] = z[i]; break;
case 2: line_buffer[i] = z[i] - z[i-stride_bytes]; break;
case 3: line_buffer[i] = z[i] - (z[i-stride_bytes]>>1); break;
case 4: line_buffer[i] = (signed char) (z[i] - stbiw__paeth(0,z[i-stride_bytes],0)); break;
case 2: line_buffer[i] = z[i] - z[i-signed_stride]; break;
case 3: line_buffer[i] = z[i] - (z[i-signed_stride]>>1); break;
case 4: line_buffer[i] = (signed char) (z[i] - stbiw__paeth(0,z[i-signed_stride],0)); break;
case 5: line_buffer[i] = z[i]; break;
case 6: line_buffer[i] = z[i]; break;
}
@ -1003,9 +1004,9 @@ static void stbiw__encode_png_line(unsigned char *pixels, int stride_bytes, int
switch (type) {
case 0: line_buffer[i] = z[i]; break;
case 1: line_buffer[i] = z[i] - z[i-n]; break;
case 2: line_buffer[i] = z[i] - z[i-stride_bytes]; break;
case 3: line_buffer[i] = z[i] - ((z[i-n] + z[i-stride_bytes])>>1); break;
case 4: line_buffer[i] = z[i] - stbiw__paeth(z[i-n], z[i-stride_bytes], z[i-stride_bytes-n]); break;
case 2: line_buffer[i] = z[i] - z[i-signed_stride]; break;
case 3: line_buffer[i] = z[i] - ((z[i-n] + z[i-signed_stride])>>1); break;
case 4: line_buffer[i] = z[i] - stbiw__paeth(z[i-n], z[i-signed_stride], z[i-signed_stride-n]); break;
case 5: line_buffer[i] = z[i] - (z[i-n]>>1); break;
case 6: line_buffer[i] = z[i] - stbiw__paeth(z[i-n], 0,0); break;
}