This makes a possible improvement to e1m3, only barely affects ad_tears,
but makes about 30% difference to gmsp3v2 (21fps to 27, and from 3300
leafs to 2700).
The rendering of the shadow maps now takes the culling information into
account resulting in a drastic reduction of work. There's still more
work to be done, but demo1 peaks at over 1000fps at 640x480, gmsp3v2 now
gets 14fps (1920x1080) near the front gate (used to be 3, then 6),
ad_tears is up to 3fps, but marcher is still unhappy, but it has
infinite radius lights, so needs more culling work (clipped light
volumes will help, I think). Also, culling lights for which nothing has
moved within their volumes will help somewhat (though not as much for
most id maps, I suspect).
Using the translucency pass made it easy to have depth-tested
translucent "solid" light volumes instead of always visible lines (which
are still an option as that's useful too). Most importantly, being able
to see the surfaces helped no end in figuring out that my hulls were
created with counter-clockwise windings instead of quake's usual
clockwise windings and thus my hulls were being rendered inside-out in
the occlusion pass.
The results of the occlusion queries give the lights that don't have a
visible hull, but unfortunately that includes any lights which the
camera is inside, but simple distance checks sort that out (with a
fudge-factor for the icosahedron vertices (1.583 (3(2+p)/(2+3p), p is
golden ratio)).
My efforts (especially the collect zone (what was I thinking)) got
tracy's knickers in a twist resulting in vanishing zones in the server.
It looks like there are some synchronisation issues between cpu and gpu,
but I'm not *too* worried about it at this stage.
The info isn't used yet, but this shows that vulkan's occlusion queries
are at least somewhat useful. However, the technique isn't perfect:
infinite radius lights (1/r and 1/r^2) are difficult to cull, and all
lights can poke through thin enough walls, and then lights containing
the camera get culled incorrectly (will need a separate test). Still, it
looks like it will help once everything is tied together.
They weren't rendering properly at all due to the matrix updates getting
overwritten by the light data (I'd forgotten to advance the packet data
pointer).
This doesn't make much of a difference on the GPU, but it drastically
cuts down CPU usage, especially for ad_tears: shadow map drawing is down
from 16.3ms to 3.7ms thanks to no having to run the alias model queues
as often.
Batching shadow map rendering needs be able to reference matrices for
multiple lights in a single batch, but the only input is the view index,
so use that to look up the matrix index rather than using it to index
the matrices directly (modulo the base index that's still there).
Actually, only 29 are used because nvidia's drivers segfault when there
are more than 29 views (regardless of the exact bit pattern in the view
mask). This will allow rendering shadow maps in large batches, which
should make for better GPU utilization.
Even that's getting pretty big, but with the quanta at 128, that's a
maximum of 8 different image sizes (which is nice for my planned
"staging image" idea).
Interestingly, this caused a reduction in memory use for some maps (but
did increase marcher's again, but not as much as the bogus rounding
did). The idea was to use sparse bindings to remap shadow map layers,
but it turns out sparse bindings are insanely slow (beyond unusable).
However, the reduction in the number of shadow map images seems to be
worth it.
Since switching to the 1.2 api as a requirement, might as well use the
relevant structs instead of extension struct (for multiview). Came up
when double-checking the max views property due to running into what
appears to be an nvidia bug where > 29 views (any bit pattern) cause a
segfault when creating the pipeline.
I had missed that upping max lights to 2048 meant that up to 12288
matrices are needed for all the possible lights. This made it so the
light type could not be encoded in id_data, but the shaders never used
it anyway. This leaves one bit free.
I'd added some developer output to see how the layers were distributed
between images and found the image widths to be... odd. It turns out I
was double-adding the shadow_quanta. Oops. Results in ~164MB less memory
used by marcher (for 32 pixel quanta).
While QFV_PacketScatterBuffer works on only one destination buffer, it
turns out it's still useful for scattering to multiple buffers, just
with multiple calls. This makes it pretty easy to combine multiple
buffer updates into a single staging buffer packet, resulting in
reducing lighting's packet use from up to 7 to just one, drastically
reducing the pressure on the stating buffer packet pool, and thus
reducing the chances of QFV_PacketAcquire stalling.
This relies on my fork of tracy: https://github.com/taniwha/tracy
on the wip-c-vulkan branch. Everything is still rather flaky though.
This necessitated the jump to vulkan 1.2 as a requirement.
Tracy is a frame profiler: https://github.com/wolfpld/tracy
This uses Tracy's C API to instrument the code (already added in several
places). It turns out there is something very weird with the fence
behavior between the staging buffers and render commands as the
inter-frame delay occurs in a very strangle place (in the draw code's
packet acquisition rather than the fence waiter that's there for that
purpose). I suspect some tangled dependencies.
I'm actually surprised anything worked, though I guess it was just the
one entry getting corrupted (and not 32, but I figured allocate slots
for all of the dynamic lights just in case). Or none, really, since
larger scenes (ie, those with multiple lights that fit in the same image
size) would result in not all the maps getting used and thus one spare
for dynamic lights.
This seems excessive, but gmsp3v2 map has 1399 lights. Worse, it has a
lot of different light sizes that go up by small increments (generally
around 10) resulting in 33 shadow map images (1 too many). Quantizing
the sizes to 32 drops this nicely to 20, and reduces memory consumption
slightly too (image buffer overhead, I guess).
This covers only the rendering of the shadow maps (actual use still
needs to be implemented). Working with orthographic projection matrices
is surprisingly difficult, partly because creating one includes the
translations needed to get the scene into the view (and depth range),
which means care needs to be taken with the view (camera) matrix in
order to avoid double-translating depending on just how the orthographic
matrix is set up (if it's set up to focus on the origin, then the camera
matrix will need translation, otherwise the camera matrix needs to avoid
translation).
This improves the projection API in that near clip is a parameter rather
than being taken directly from the cvar, and a far clip (ie, finite far
plane) version is available (necessary for cascaded shadow maps as it's
rather hard to fit a box to an infinite frustum).
Also, the orthographic projection matrix is now reversed as per the
perspective matrix (and the code tidied up a little), and a version that
takes min and max vectors is available.
gcc didn't like a couple of the changes (rightly so: one was actually
incorrect), and the fix for qfcc I didn't think to suggest while working
with Emily.
The general CFLAGS etc fixes mostly required just getting the order of
operations right: check for attributes after setting the warnings flags,
though those needed some care for gcc as it began warning about main
wanting the const attribute.
Fixing the imui link errors required moving the ui functions and setup
to vulkan_lighting.c, which is really the only place they're used.
Fixing a load of issues related to autoconf and some small source-level issues to re-add clang support.
autoconf feature detection probably needs some addressing - partially as -Werror is applied late.
Lines are drawn for a light's leaf, the leafs visible to it, or those in
its efrags chain. Still no idea why lights are drawing when they
shouldn't. Deek suggest holes in the map, but I think if that was the
case, there'd be something visible. My suspicion is I'm doing something
wrong in with efrags.
This has resulted in some rather interesting information: it seems the
surfaces (and thus, presumably bounding boxes) for leafs have little to
do with the actual leaf node's volume.
This also fixes the segfault in the previous commit.
Dynamic light shadow sizes are fixed, but can be controlled via the
dynlight_size cvar (defaults to 250).
Other than the rather bad shadow acne, this is actually quake itself
working nicely. Still need to get directional lights working for
community maps, and all sorts of other little things (hide view model,
show player, fix brush backfaces, etc).
This takes care of the type punning issue by each pass using the correct
sampler type with the correct view types bound. Also, point light and
spot light shadow maps are now guaranteed to be separated (it was just
luck that they were before) and spot light maps may be significantly
smaller as their cone angle is taken into account. Lighting is quite
borked, but at least the engine is running again.
This gets everything but the actual shadow map bindings working: the
validation layers don't like my type punning (which may well be the
right thing) and specialization constants don't help (yet, anyway) but I
want to get things into git.
Directional lights don't get correct matrices yet as I need to study the
math involved for cascaded shadow maps (and id maps don't have
directional lights).
Getting spotlights working correctly was insanely frustrating: I just
couldn't get the entities into the view of the spotlight with any
sensible combination of inverses and the z_up matrix. It turned out it
was all due to an incorrect reference vector: it was +Z instead of +X.
It turns out bsp faces are still back-face culled despite the null point
being on the front of every possible plane... or really, because it's on
the front of every possible plane: sometimes the back face is the front
face, and this breaks the face selection code (a separate traversal
function will be needed for non-culling rendering).
Despite that, other than having to deal with different pipelines,
getting the model renderers working went better than expected.
This involved rewriting the descriptor update code too, but that now
feels cleaner.
The matrices are loaded into a storage buffer as it can get quite big at
6 matrices per light (and the current max lights is 768).
The parameter will be passed on to the pipeline tasks in their task
context, allowing for communication between the subsystem calling
QFV_RunRenderPass and the pipeline tasks (for the case of lighting,
passing the current matrix base index).
