GL Quake was weird, culling front faces. Partly understandable, since
Quake's front order is clockwise and GL's default order is
counter-clockwise. However, since the order can be specified, that should
be done instead. Thus, specify the winding order as clockwise (for quake's
data), set culling for back-face removal, and then mess with the winding
direction in the mirror and fish-eye code.
The links are now in "instance surfaces". For non-instanced models (world,
doors, plats etc (ie, world and its sub-models)), there will be one
instance surface per model surface. However, for instanced models (ammo
boxes etc), there will be many, dynamically allocated (not yet
implemented). This commit gets the static instance surfaces working.
This has several benifits:
o The silly issue with alias model pitches being backwards is kept out
of the renderer (it's a quakec thing: entites do their pitch
backwards, but originally, only alias models were rotated. Hipnotic
did brush entity rotations in the correct direction).
o Angle to frame vector conversions are done only when the entity's
angles vector changes, rather than every frame. This avoids a lot of
unnecessary trig function calls.
o Once transformed, an entity's frame vectors are always available.
However, the vectors are left handed rather than right handed (ie,
forward/left/up instead of forward/right/up): just a matter of
watching the sign. This avoids even more trig calls (flag models in
qw).
o This paves the way for merging brush entity surface rendering with the
world model surface rendering (the actual goal of this patch).
o This also paves the way for using quaternions to represent entity
orientation, as that would be a protocol change.
It turns out that due to the way we do fullbrights, nothing special needs
to be done to get the fullbright texture blended with the model even when
fog is enabled.
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.
Move the texture coordinates in 1/4 of a pixel. To avoid unnecessary
calculations, pre-caclulate the character cell texture coordinates and
blast them into the the texture coordinate array.
r_skyname now acts as the default sky to use when no sky name is specified
by other means ("none" is still no sky). 'loadsky foo' will load the
"foo*" sky textures, 'loadsky none' gives the default sky, and 'loadsky
""' causes uses r_skyname.
