diff options
| author | Søren Sandmann Pedersen <ssp@redhat.com> | 2012-04-05 00:42:55 -0400 |
|---|---|---|
| committer | Søren Sandmann Pedersen <ssp@redhat.com> | 2012-04-20 10:17:13 -0400 |
| commit | 4d2fee14063b960c6b81b55dd3aa94b956d23eeb (patch) | |
| tree | 829b7e9e460eb381868d8e61efcc00ad34a5574f | |
| parent | e2917645846b64fdc7f2190806c97b0ef4b0fd5b (diff) | |
test/utils.c: Clip values to the [0, 255] interval
Unpremultiplying a superluminescent pixel can result in values greater
than 255.
| -rw-r--r-- | test/utils.c | 13 |
1 files changed, 10 insertions, 3 deletions
diff --git a/test/utils.c b/test/utils.c index cc0365aa..c1bf6dc2 100644 --- a/test/utils.c +++ b/test/utils.c @@ -358,9 +358,16 @@ a8r8g8b8_to_rgba_np (uint32_t *dst, uint32_t *src, int n_pixels) if (a != 0) { - r = (r * 255) / a; - g = (g * 255) / a; - b = (b * 255) / a; +#define DIVIDE(c, a) \ + do \ + { \ + int t = ((c) * 255) / a; \ + (c) = t < 0? 0 : t > 255? 255 : t; \ + } while (0) + + DIVIDE (r, a); + DIVIDE (g, a); + DIVIDE (b, a); } *dst8++ = r; |