The main goal was to get visframe out of mnode_t to make it thread-safe
(each thread can have its own visframe array), but moving the plane info
into mnode_t made for better data access patters when traversing the bsp
tree as the plane is right there with the child indices. Nicely, the
size of mnode_t is the same as before (64 bytes due to alignment), with
4 bytes wasted.
Performance-wise, there seems to be very little difference. Maybe
slightly slower.
The unfortunate thing about the change is the plane distance is negated,
possibly leading to some confusion, particularly since the box and
sphere culling functions were affected. However, this is so point-plane
distance calculations can be done with a single 4d dot product.
Still work with gcc, of course, and I still need to fix them properly,
but now they're actually slightly easier to find as they all have vec_t
and FIXME on the same line.
I meant to do this a while ago but forgot about it. Things are a bit of
a mess in that the renderer knows too much about entities, but
eventually the renderer will know about only things to render (meshes,
particles, etc).
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.
This moves the common camera setup code out of the individual drivers,
and completely removes vup/vright/vpn from the non-software renderers.
This has highlighted the craziness around AngleVectors with it putting
+X forward, -Y right and +Z up. The main issue with this is it requires
a 90 degree pre-rotation about the Z axis to get the camera pointing in
the right direction, and that's for the native sw renderer (vulkan needs
a 90 degree pre-rotation about X, and gl and glsl need to invert an
axis, too), though at least it's just a matrix swizzle and vector
negation. However, it does mean the camera matrices can't be used
directly.
Also rename vpn to vfwd (still abbreviated, but fwd is much clearer in
meaning (to me, at least) than pn (plane normal, I guess, but which
way?)).
So far, in gl and glsl, but viewposition is much clearer than r_origin
(despite being the same thing), and modelorg is just confusing (I think
it's the view position relative to the current model).
r_screen because of SCR_UpdateScreen, and r_cvar because the cvars
really should never have been in a plugin in the first place (and
r_screen needed access).
It turns out glsl, sw and sw32 weren't getting any benefit from R_CullBox
because the frustum wasn't setup :P. Get another 8% out of bigass1
(174->184fps). bigass1 now runs 2x as fast as it did before I started this
optimisation run :)
Where possible, symbols have been made static, prefixed with gl_/GL_ or
moved into the code shared by all renderers. This will make doing plugins
easier but done now for link testing.
Also some small cleanups in particles.
Brighten grenade smoke a tiny bit, so it's not so invisible in the typically dark quake areas.
And some minor cleanups to water rendering.
