I am writing some alpha-blending code, and I realized that premultiplied alpha is enough for most cases.
So I thought about using only premultiplied alpha on my engine code to simplify the structure. Anyway premultiplication itself drops color information on low-alpha pixels, so it can be problematic if I need some kind of serious composition.
But in games, I can't figure out when I need that composition which needs straight alpha. Do you have have case we need straight alpha in trivial(?) game graphics?