Is this AdditiveBlendOp also asymetrical ? My addColor function will give the first color full priority over the second color (ie: only add a little bit of the second color if they both have only a little bit of transparency)
(0, 0, 0, 200) + (255, 255, 255, 200) => (55, 55, 55, 255)
(255, 255, 255, 200) + (0, 0, 0, 200) => (200, 200, 200, 255)
I thought the normal Paint.Net functions would give (127, 127, 127, 255) in both cases.