The software renderer uses Bresenham's line slice algorithm as presented
by Michael Abrash in his Graphics Programming Black Book Special Edition
with the serial numbers filed off (as such, more just so *I* can read
the code easily), along with the Chen-Sutherland line clipping
algorithm. The other renderers were more or less trivial in comparison.
One more step towards BSP thread-safety. This one brought with it a very
noticeable speed boost (ie, not lost in the noise) thanks to the face
visframes being in tightly packed groups instead of 128 bytes apart,
though the sw render's boost is lost in the noise (but it's very
fill-rate limited).
This is next critical step to making BSP rendering thread-safe.
visframe was replaced with cluster (not used yet) in anticipation of BSP
cluster reconstruction (which will be necessary for dealing with large
maps like ad_tears).
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.
The map uses 41% of a 4k light map scrap, and 512 texture descriptors
wasn't enough for vulkan. Ouch. I do need to get cvars on these things,
but this will do for now (decades later...)
And maybe a nano-optimization. Switching from (~side + 1) to (-side)
seems to give glsl a very tiny speed boost, but certainly doesn't hurt.
Looking at some assembly output for the three cases, the two hacks seem
to generate the same code as each other, but 3 instructions vs 6 for ?:.
While ?: is more generically robust, the hacks are tuned for the
knowledge side is either 0 or 1. The later xor might alter things, but
at least I now know that the hack (either version) is worthwhile.
This makes it much easier to see just what is being done to build a
polygon to be passed to the GPU, and it served as a test for the
lightmap st changes since Vulkan currently never used them.
The parsing of light data from maps is now in the client library, and
basic light management is in scene. Putting the light loading code into
the Vulkan renderer was a mistake I've wanted to correct for a while.
The client code still needs a bit of cleanup, but the basics are working
nicely.
This replaces *_NewMap with *_NewScene and adds SCR_NewScene to handle
loading a new map (for quake) in the renderer, and will eventually be
how any new scene is loaded.
I doubt the calls were ever actually made in a normal map due to the
node actually being a node when breaking out of the loop, but when I
experimented with an empty world model (no nodes, one infinite empty
leaf) I found that visit_leaf was getting called twice instead of once.
This is an extremely extensive patch as it hits every cvar, and every
usage of the cvars. Cvars no longer store the value they control,
instead, they use a cexpr value object to reference the value and
specify the value's type (currently, a null type is used for strings).
Non-string cvars are passed through cexpr, allowing expressions in the
cvars' settings. Also, cvars have returned to an enhanced version of the
original (id quake) registration scheme.
As a minor benefit, relevant code having direct access to the
cvar-controlled variables is probably a slight optimization as it
removed a pointer dereference, and the variables can be located for data
locality.
The static cvar descriptors are made private as an additional safety
layer, though there's nothing stopping external modification via
Cvar_FindVar (which is needed for adding listeners).
While not used yet (partly due to working out the design), cvars can
have a validation function.
Registering a cvar allows a primary listener (and its data) to be
specified: it will always be called first when the cvar is modified. The
combination of proper listeners and direct access to the controlled
variable greatly simplifies the more complex cvar interactions as much
less null checking is required, and there's no need for one cvar's
callback to call another's.
nq-x11 is known to work at least well enough for the demos. More testing
will come.
This fixes (*ahem*) the vulkan renderer segfaulting when attempting to
take a screenshot. However, the image is upside down. Also, remote
snapshots and demo capture are broken for the moment.
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.
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).
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.
Other than the view model (undecided on the approach) this has
R_RenderView pretty much pulled out of the low level renderers. With
this, I'll be able to focus on scene handling for a bit then getting
shadows and fisheye working (again for fisheye).
r_screen isn't really the right place, but it gets the scene rendering
out of the low-level renderers and will make it easier to sort out
later, and hopefully easier to figure out a good design for vulkan.
The code is really part of scene (not a typo wrt r_screen: that is
misnamed as such, or at least SCR_UpdateScreen needs to be split into
screen (2d overlay, really) and scene updates).
This breaks fisheye rendering as the fisheye code calls the actual scene
render code multiple times, but the fisheye code is called by said scene
render code via a diversion. The fisheye needs to be moved out to the
high level scene render, but that will takes some extra work for frame
buffer setup.
Finally. I never liked it (felt bad adding it in the first place), and
it has caused confusion with function and global variable names, but it
did let me get the render plugins working.
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).
GL still has its own functions for enabling and disabling fog while
rendering, but GLSL doesn't need such (thanks to the shaders), nor will
vulkan (and the software renderers don't support fog).
This is a step towards high-level unification of the renderers, as far
as possible keeping only actual low-level implementation details in the
individual renderers (some higher level stuff, eg shadows, is expected
to be per-renderer as some things are just not feasible to implement in
all renderers). However, the idea is to move the high-level
functionality into scene rendering.
Only CaptureBGR is per-renderer as the rest of the screenshot code uses
it to do the actual capture (which is target dependent). Vulkan is
currently broken due to capture being an asynchronous process and the
rest of the code expecting capture to be synchronous (also, bgr vs rgb).
The best thing is all renderers now write the same format (currently
png).
While there's currently only the one still, this will allow the entities
to be multiply queued for multi-pass rendering (eg, shadows). As the
avoidance of putting an entity in the same queue more than once relies
on the entity id, all entities now come from the scene (which is stored
in cl_world in the client code for nq and qw), thus the extensive
changes in the clients.
GL and GLSL were drawing the view model after particles instead of
before. For GL, this is likely due to avoiding fog affecting the view
model (which I think is not the right thing to do), and GLSL due to
copying GL (because I had no idea at the time). This makes the two
renderers consistent with the software renderers, and might even speed
things up a little as that's one less set of blends to do when the
particles are covered by the view model (I don't expect much
difference).
While I doubt the difference is all that significant, this should speed
up entity rendering because it cuts out a lot of branching, and
eliminates scanning the same list multiple times only to not do anything
for large chunks of the list.
The actual view and projection matrices are now consistent with vulkan,
with the vulkan-gl disparity moved into adjustment matrices. The goal is
to allow the same camera data and code to be used in all renderers. The
extra matrix multiplication shouldn't be too expensive as it occurs only
when the field of view (not often, under user control) or near and far
clip distances (very rarely) change.
This takes care of the global variables to a point (there is still the
global struct shared between the non-vulkan renderers), but it also
takes care of glsl's points-only rendering.
After yesterday's crazy marathon editing all the particles files, and
starting to do another big change to them today, I realized that I
really do need to merge them down. All the actual spawning is now in the
client library (though particle insertion will need to be moved). GLSL
particle rendering is semi-broken in that it now does only points (until
I come up with a way to select between points and quads (probably a
context object, which I need anyway for Vulkan)).
This has the advantage of getting entity_t out of the particle system,
and much easier to read math. Also, it served as a nice test for my
particle physics shaders (implemented the ideas in C). There's a lot of
code that needs merging down: all but the actual drawing can be merged.
There's some weirdness with color ramps, but I'll look into that later.
As the sw renderer's implementation was the closest to id's, it was used
as the model (thus a fair bit of cleanup is still needed). This fixes
some incorrect implementations in glsl and gl.
