Re: Compositing and alpha

[Alexander Malmberg]

> > My experience also shows this. Tests on OS 4.2 and ghostscript show that
> > drawing with alpha does not blend, but overwrites color and alpha.
> 
> This makes a lot of sense. If all your drawing blends thenyou ahve no way of
> replacing the alpha which is in the window!

NSCompositeClear is the easiest way. You can do the same things in both
models, you just need to do them differently. Both are internally
consistent and make sense, so it's an arbitrary choice.

> OpenStep doesnt blend unless
> you explicitly ask it to.
>
> -bat.

- Alexander Malmberg