I've decided that alias model skins should be in a single four-level
array texture rather than spread over four textures, but there's no way
I want to write that code again: getting it right was hard enough the
first time :P
This makes tex_t more generally useable and probably more portable. The
goal was to be able to use tex_t with data that is in a separate chunk
of memory.
The sky texture is loaded with black's alpha set to 0. While this does
hit both layers, the screen is cleared to black so it shouldn't be a
problem (and will allow having a skybox behind the sheets).
Copying data from the wrong buffer was the cause of the corrupted brush
model vertices, and then lots of little errors (mostly forgetting to
multiply by bpp) for textures.
I had originally planned on mixing the stage management with general
texture support code like I did in glsl, but I think that was a mistake
and I did keep looking for scrap.[ch] when I wanted to edit something to
do with the scrap...
It optionally generates mipmaps, and supports the main texture types
(especially for texture packs), including palettes, but is otherwise
rather unsophisticated code. Needs a lot of work, but testing first.
