// Actually, if _either_ image has blank alpha, our output will have
// blank alpha, too (this only tells the framework that having _both_
// images with blank alpha would result in blank alpha).
// However, understanding that would require changes
// to EffectChain, so postpone that optimization for later.
// Actually, if _either_ image has blank alpha, our output will have
// blank alpha, too (this only tells the framework that having _both_
// images with blank alpha would result in blank alpha).
// However, understanding that would require changes
// to EffectChain, so postpone that optimization for later.