[sldev] Re: possible rendering improvement

[Argent Stonecutter]

> Without looking at the code, it is probably a question about what's  
> more
> expensive: Checking _every_ surface's alpha-setting or rendering
> invisible surfaces. (Maybe we should take a walk through the grid  
> with a
> modified client that counts surfaces...)

The client has to check every surface's alpha setting *anyway* to  
tell the GPU what it is, so simply not sending the surface to the GPU  
at all if the Alpha is 0 should be almost free.

Checking the texture for ones that are completely transparent may be  
a little more difficult, but again it has to process the texture  
before uploading it to the GPU, and having the client keep track of  
the textures that have no non-zero pixels in the alpha mask wouldn't  
take much storage, one extra bit per texture...