Re: [AD] possible speed improvements on current allegro blenders

[Robert Ohannessian <ohannessian@xxxxxxxxxx>]

Javier Gonzalez wrote:

> Hello, I just noticed allegro doesn't take adventage of special cases 
> in the
> blenders to speed up this operation
> for example, in the trans blender, if the alpha is 255 (one of the 
> most used
> cases) it could avoid reading the back pixel and simply returning the 
> pixel
> to be put



Isn't this what FBlend is for? :-)


> Same thing if the alpha is 0, it could simply avoid reading and do not
> putpix anything (or if that can't be done, simply return the value of the
> getpix)


That's not always possible for the (generic) way that Allegro does 
blending. An alpha of 0 may not mean to "do nothing".