Hi,
I played around with it a bit, but I'm not sure exactly what the problem
is, nor do I have time to figure out exactly what you're trying to do about
it.
I didn't run through your implementations in detail, but I did notice that
you're copying surface(s) in every one. I bet this eats a lot of time.
Certainly, the blits will too. As you observed, a GPU is great for this
sort of thing. If you haven't used PyOpenGL before, it might not be as hard
as you think to get simple blitting function correct. Actually, I think
there are already several projects on PyGame.org that provide it. In any
case, GPUs exist to draw things. They're very good at it. It is wise to
take them up on the offer.
Lastly, a correct-ish blitting function to use (assuming no SSS or
radiosity) in pseudocode:
result = 0
for all surfaces:
light_at_surface = light intensity *
product_of_alphas_between_light_and_surface
result += light_at_surface * surface_reflectance *
product_of_surface_alphas_between_surface_and_eye
I bet that can be factored into a 1-pass-per-surface algorithm.
Ian
