[Scummvm-devel] blendPixelPtr()

[Willem Jan Palenstijn]

On Fri, Jan 10, 2014 at 02:36:24PM +0100, Marcus Comstedt wrote:
> 
> Hi.
> 
> Could someone please explain what the deal is with commit 264ba4a9?
> 
> The message says "Keep dst alpha unchanged when blending colours", and
> I can see that the code change does just that, but...  WHY?
> 
> Now the resulting alpha is incorrect.  Let's say that the old pixel
> was completely transparent (R=G=B=A=0.0).

This should never happen. The screen should always be initialized to A=1.0.

Is this not the case for you?

-Willem Jan