// differently in different modes.
// 0.0 and 1.0 are interpreted the same, no matter the gamma ramp.
-// Alpha is not affected by gamma.
+// Alpha is not affected by gamma per se, but the combination of
+// premultiplied alpha and non-linear gamma curve does not make sense,
+// so if could possibly be converting blank alpha to non-blank
+// (ie., premultiplied), we need our output to be in linear light.
bool PaddingEffect::needs_linear_light() const
{
if ((border_color.r == 0.0 || border_color.r == 1.0) &&
(border_color.g == 0.0 || border_color.g == 1.0) &&
- (border_color.b == 0.0 || border_color.b == 1.0)) {
+ (border_color.b == 0.0 || border_color.b == 1.0) &&
+ border_color.a == 1.0) {
return false;
}
return true;