For now, OpenGL and Vulkan renderers are broken as I focused on getting
the software renderer working (which was quite tricky to get right).
This fixes a couple of issues: the segfault when warping the screen (due
to the scene rendering move invalidating the warp buffer), and warp
always having 320x200 resolution. There's still the problem of the
effect being too subtle at high resolution, but that's just a matter of
updating the tables and tweaking the code in D_WarpScreen.
Another issue is the Draw functions should probably write directly to
the main frame buffer or even one passed in as a parameter. This would
remove the need for binding the main buffer at the beginning and end of
the frame.
Its guts have been moved to D_Init temporarily while I work on the
frame buffer design. This is actually a big part of that work as it
moves most of the frame buffer creation into the one place, making it
easier to ensure I get all the sub-buffers and caches created.
I'd been considering it for a while, but in the end, all the issues it
presented made me decide it wasn't worth merging and was never really
worth keeping: it was a neat proof of concept but of little actual use,
especially now everyone either has an OK GPU or would want to stick to
8-bit rendering anyway (sorry L-Havoc).
However, both it and my merge work are preserved in git history :)
I got tired of having to maintain two separate software renderers, but
didn't want to just nuke sw32, so its core changes are merged into sw.
Alias model rendering is broken, but I know exactly what's wrong and how
to fix it, just need to take care due to asm.
This paves the way for clean initialization of the Vulkan renderer, and
very much cleans up the older renderer initialization code as gl and sw
are no longer intertwined.
