What changed in EDuke32, build by build

Bugged since forever and would have floors and ceilings stay put when alt-wheeling in mapster.

The visibility calculation relies on the distance, which might not be entirely accurate in rotatesprite, so maybe it'll be too dark in some cases.

Lightmaps are already opt-in anyway.

And hook them up to cstat 128 (half-submerged, 'c' in mapster).

And hook it up to SE cstat 64 ('1' in mapster32). This disables both lightmaps and shadow maps for the spotlight; please let me know if you have a usecase where you want lightmaps but no shadow maps for specific lights.

This was broken ever since updatesprite() had been forked off drawsprite() and would cause static lights to never hit static sprites until one or the other changed, after which the light would always get culled against outdated sprite geometry.

Since updatesprite() only happens once for static sprites, avoiding light culling if we hit it in a shadow pass means that sprite will never be lit as long as that happens.

With VBOs enabled, the virtual pointer to the geometry of frame 0 of a model is always NULL. This was confusing the polymer code responsible for deciding whether to enable smooth animations or not, which meant that any animation that would loop to frame 0 would do it as if animation interpolation was disabled, which looks very choppy.

This also fixes a warning when building for Windows.

Getting the texture handles without requiring invalidation means we can handle ART-animating tilenums without impacting performance too much.

Polymer has a hack that snaps horiz values of spotlights between 90 and 110 to 90 and 110 to avoid triggering aliasing artifacts with perfectly horizontal spotlights. Propagate that change all the way to the spotlight SE sprite so that the code won't think that the horiz is always different from the light and mark it invalid each frame.

This won't actually do anything until the a debug bit is added when creating the context, but that requires support for GLX_create_context which SDL doesn't support. I'll add support for WGL_create_context to winlayer in a bit as a stopgap. Also updates our local copy of glext.h with a fresh one from the Khronos registry.

We need to Y-invert the projection texcoords when sampling from the lightmap.