Fix alpha under equation according to porter-duff and user docs that state that effect should invert he order of channels and reduce to alpha over when factor is 1.0. BTW, we don't really expose any factor here...lost feature from 2.49?
Fix alpha under equation according to porter-duff and user docs that state that effect should invert he order of channels and reduce to alpha over when factor is 1.0. BTW, we don't really expose any factor here...lost feature from 2.49?