The tests fail due to differences in how clang and gcc treat floating
point to unsigned integral type conversions when the values overflow. It
wouldn't be so bad if clang was consistent with conversions to 32-bit
unsigned integers, like it seems to be with conversion to 64-bit
unsigned integers.
With this, the "get QF building with clang" mini-project is done and I
won't have to panic when someone comes to me and asks if it will work.
At worst, there'll be a little bit-rot.
clang doesn't like the same variable name being used in nested
expression statements, so give the "safety" variables in reused macros
semi-meaningful (based on macro name) tails to keep them separate.
Only edicts themselves get a smaller alignment (4, 8 or 32 bytes,
depending on hardware and progs version). I didn't want to waste too
much memory on edict alignment for progs that don't need any better than
void *, but the zone really wants 64 bytes, and the stack might as well
have 64 bytes as well. Fixes a segfault when running v6 progs in a clang
build (clang got really agressive with simd in zone.c).
gcc and clang have rather different swizzle builtins, but both do a nice
job of optimizing the intuitive initializer swizzle (I think gcc 8(?)
didn't do such a good job thus my use of __builtin_shuffle).
The "not" because I'm pretty sure they're false positives due to when
the function is called, but clang doesn't know that (wonder why gcc was
ok with it).
clang doesn't like anything but a bare 0 as null (and in some of the
cases, it was quite right: '\0' should not be treated as a null
pointer). And the crashers were just for paranoia and probably aren't
needed any more (kept for now, though).
It seems clang defaults to unsigned for enums. Interestingly, gcc was ok
with the checks being either way. I guess gcc treats enums that *can* be
unsigned as DWIM.
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.
While clang accepts gcc's optimization options, it produces a warning
when it ignores them, so need to set -Werror before checking for those
options when building with -Werror otherwise the build will fail.
Viewport and FOV updates are now separate so updating one doesn't cause
recalculations of the other. Also, perspective setup is now done
directly from the tangents of the half angles for fov_x and fov_y making
the renderers independent of fov/aspect mode. I imagine things are a bit
of a mess with view size changes, and especially screen size changes
(not supported yet anyway), and vulkan winds up updating its projection
matrices every frame, but everything that's expected to work does
(vulkan errors out for fisheye or warp due to frame buffer creation not
being supported yet).
If the entity didn't have a known model type, R_StoreEfrags would get
stuck in an infinite loop (fortunately, never actually happened. The
result of making it not call Sys_Error for unknown models)).
Definitely not something for the renderer to care about directly (ie, at
most, a post-process filter setting or palette update, which is how it
actually is currently).
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).
The quake-specific enums are now in the client header, and the particle
system now has a gravity field rather than getting it from
vid_render_data (which I hope to eventually get rid of entirely).
r_refdef is really meant for holding the various screen "constants" for
the software renderer rather than the more generic scene stuff. All the
fields referenced by the low level rendering code (especially assembly)
have been moved to the beginning of the struct (and nicely fit within 64
bytes). The other fields should be moved elsewhere, but not this commit.
On top of that, R_ViewChanged is much easier to read, and there are
fewer static globals.
Now GL perspective matrix setup matches that of GLSL and Vulkan, and
GL's z_up matrix matches GLSL's (as it should, since they're really
going through the same API). GL also needs the depth adjustmet matrix
now. Other than having to google the docs for glFrustum, there's nothing
wrong with the function itself, but it's nice to have direct control
over the matrices.
In the process, I discovered how horribly confused I've been at times
with respect to the handedness of GL and Quake: GL is right-handed
(y-up, z-out, x-right), as is Quake itself (but z-up, y-left, x-in), but
as the perspective matrix used in the three renderers expects z-in,
having x-right and y-up makes the matrix effectively left-handed (not
for Vulkan though, because there it's y-down, x-right, z-up, so
right-handed again).
Of course, it's not as correct as glsl or sw due to using polygons and
uvs rather than a fragment shader (not that such is out of the question
since GL 3.0 is requested, but I don't feel like getting shaders going
just for a couple of post-processing effects in an obsolete renderer).
While it's not where I want it to be, it at least now no longer messes
with frame buffer binding or the view ports. This involved switching
around buffers in D_WarpScreen so that the main buffer could be bound
before post-processing.
The cvar setup for particles is a bit wonky in that the arrays get
initialized using the default max particle count but never updated.
Though things could be improved some more, this solution works (and has
been more or less copied to gl, but I couldn't reproduce the crash
there, or even the valgrind error).
The code dealing with state is a bit of a mess, but everything is
working nicely. Get around 400fps when all 6 faces need to be rendered
(no surprise: it should be about 1/6 of that for normal rendering). The
messy state handling code did not come as a surprise as I suspected
there were various mistakes in my scene rendering "recipe", and fisheye
highlighted them nicely (I'm sure getting this stuff working in Vulkan
will highlight even more issues).
Finally, after a decade :P Looks pretty good, too, and is (almost)
properly scaled to the resolution (almost because the effect is a little
squashed, but I think the sw renderer does the same).
The GLSL compiler requires any #version lines to be the first (real)
line of the program, even #line causes an error, so if the first line of
the chunk starts with #version, insert the #line directive as the second
line.