I guess it's kind of UB, but it's handy for images that will be
conditionally written by the GPU but need to be in shader-read-only for
draw calls and the validation layers can't tell that the layers won't be
used.
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).
They're now qfv_* and shared within the vulkan renderer. qfv_z_up cannot
be shared across renderers as they have their own ideas for the world
frame. qfv_box_rotations currently can't be shared across renderers
because if the Y-axis flip and the way it's handled, but sharing should
be achievable by modifying the other renderers to handle the sides
correctly (glsl and gl need to do lookups for the side enums, sw just
needs to be shown which way is up).
Using set iterators can be quite a lot faster for sparse sets due to the
function call overhead in testing each element. Times for ad_tears
dropped from about 1200us to about 670us (hard to say due to there being
only 3 data points and a lot of noise in the time).
If a step has process tasks, any render or compute
pipelines/renderpasses are **not** run automatically: the idea is the
process tasks need to run the relevant pipelines in a custom manner but
needs the objects to be created.
The recent light changes highlighted that the renderer does not own the
efrags (segfault in qwaq when shutting down my test scene). After
digging through the history of efrag clearing, it turns out that the
renderer never owned them, I just didn't understand the concept of
scenes at the time that I moved efrags into the renderer.
This eliminates the O(N^2) (N = map leaf count) operation of finding
visible lights and will later allow for finer culling of the lights as
they can be tested against the leaf volume (which they currently are
not as this was just getting things going). However, this has severely
hurt ad_tears' performance (I suspect due to the extreme number of
leafs), but the speed seems to be very steady. Hopefully, reconstructing
the vis clusters will help (I imagine it will help in many places, not
just lights).
The grid calculations are modified from those of Inigo Quilez
(https://iquilezles.org/articles/filterableprocedurals/), but give very
nice results: when thin enough, the lines fade out nicely instead of
producing crazy moire patterns. Though currently disabled, the default
planes are the xy, yz and zx planes with colored axes.
Based on the article
(https://developer.nvidia.com/content/depth-precision-visualized), this
should give nice precision behavior, and removes the need to worry about
large maps getting clipped. If I'm doing my math correctly, despite
being reversed, near precision is still crazy high. And (thanks to the
reversed depth) about a quarter of a unit (for near clip of 4) out at 1M
unit distance.
Due to doing most of my testing using the demos, I hadn't noticed the
double-draw until flying around with the debug camera (and it showed as
a weird shimmer behind the sky layers).
The lights debug is from the light splat experiment (this is why I kept
the code), and the bsp debug is based on that. Both currently disabled
for now until I get UI controls in.
SCR_UpdateScreen_Legacy now takes only the screen functions pointer (it
didn't need camera or realtime), and the camera sizzle code has been
moved into one place to make cleaning it up easier (when I get around to
auditing AngleVectors etc).
There's still the problem with unused variables when building for
windows because of vulkan debug stuff, but this fixes the important
errors. It actually still works (at least under wine).
The biggest change was splitting up the job resources into
per-render-pass resources, allowing individual render passes to
reallocate their resources without affecting any others. After that, it
was just getting translucency and capture working after a window resize.
It looks horrible due to the lack of lighting etc, but it's good enough
for basic testing, especially of my render job design (that passed with
flying colors).
I'm not sure I like fontconfig (docs are...), but it is pretty standard,
and I was able to find some reasonable examples on stackexchange
(https://stackoverflow.com/questions/10542832/how-to-use-fontconfig-to-get-font-list-c-c).
Currently, only the one font is handled, no font sets for fall backs
etc. It's meant for the debug UI I'm working on, so that shouldn't be a
big deal.
