On Wed, Nov 16, 2005 at 10:27:30AM +0000, Mark Adams wrote:
> > That restriction seems artificial at least for using AiRGB
> > source surfaces because it should be a simple matter of inverting the
> > alpha with the blending functions.
> 
> Correct.  I did look into this and concluded that I could support
> AiRGB as a source format fairly easily.  Unfortunately, the use case
> you really want is AiRGB as destination and I can't see an easy way of
> doing that (but that doesn't mean there isn't one!).  Any suggestions?

Ugh, scratch that source suggestion. I'm not sure what I was thinking 
but even though you could get correct RGB output with AiRGB sources the 
resulting alpha value would still be wrong.

a = Sa * Sfunc + Da * Dfunc

You can invert the alpha in Sfunc and Dfunc but you can't invert Sa :(

Destination alpha has the same problem, and the problem that you can't 
invert "a" after the blending :(

-- 
Ville Syrjälä
[EMAIL PROTECTED]
http://www.sci.fi/~syrjala/

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