This is the first step towards component-based entities.
There's still some transform-related stuff in the struct that needs to
be moved, but it's all entirely client related (rather than renderer)
and will probably go into a "client" component. Also, the current
components are directly included structs rather than references as I
didn't want to deal with the object management at this stage.
As part of the process (because transforms use simd) this also starts
the process of moving QF to using simd for vectors and matrices. There's
now a mess of simd and sisd code mixed together, but it works
surprisingly well together.
There's still the memory management itself to clean up, but the main
code no longer uses any static/global variables (holdover from when the
function was recursive rather).
This is a big step towards a cleaner api. The struct reference in
model_t really should be a pointer, but bsp submodel(?) loading messed
that up, though that's just a matter of taking more care in the loading
code. It seems sensible to make that a separate step.
I got rather tired of there being multiple definitions of mostly compatible
plane types (and I need a common type anyway). dplane_t still exists for
now because I want to be careful when messing with the actual bsp format.
When R_AddEfrags is used (as is the case in nq), this function is
redundant. Brush models in qw are currently broken (invisible), but that's
just a matter of getting qw to use R_AddEfrags instead of R_NewEntity.
This removal should speed up the software renderers a little bit.
a static `stack') to avoid the function call overhead. this cuts about 40%
of the execution time from this function.
No matter what I tried, best results were obtained using __builtin_expect,
so make sure non-gcc compilers do the right thing when they encounter it.
