Implement PushBuffer

[VReaperV]

Requires #1683

Add PushBuffer, update uniforms to have an updateType. The CONST and FRAME uniforms are written into a uniform buffer after the map is loaded/at the start of a frame. This allows skipping some of the glUniform*() calls to decrease the amount of overhead.

This largely re-uses the existing functionality added for the material system.

This will also be needed for #1587

[slipher]

This can be rebased now.

[VReaperV]

This can be rebased now.

Done.

[slipher]

Some issues found with testing:

1. Fog is not rendered if material system is enabled.
2. In one scene from my test script the dynamic light from the Painsaw is not rendered. I can't observe this with manual testing so I'd have to investigate more to provide a reliable repro.

[slipher]

2. In one scene from my test script the dynamic light from the Painsaw is not rendered. I can't observe this with manual testing so I'd have to investigate more to provide a reliable repro.

Now I found a way. Set common.framerate.max 3 and fire the Painsaw once. On master you will see a frame with the realtime light rendered, but on this branch no. Maybe there is some issue with data being a frame out of date.

[VReaperV]

1. Fog is not rendered if material system is enabled.

Fixed.

[VReaperV]

Now I found a way. Set common.framerate.max 3 and fire the Painsaw once. On master you will see a frame with the realtime light rendered, but on this branch no. Maybe there is some issue with data being a frame out of date.

Also fixed.

[slipher]

I confirm the 2 previous bugs are fixed. But I get the depth fade issue from #1676 again with this branch when enabling material system. It happens with any depth fade regardless of alpha tests, polygon offset etc. The bug reappears as of the first usable commit Add the remaining code for the global UBO in PushBuffer. (The first four commits don't build; GLUniform._global -> _updateType builds but doesn't render anything.)

[VReaperV]

I confirm the 2 previous bugs are fixed. But I get the depth fade issue from #1676 again with this branch when enabling material system. It happens with any depth fade regardless of alpha tests, polygon offset etc. The bug reappears as of the first usable commit Add the remaining code for the global UBO in PushBuffer. (The first four commits don't build; GLUniform._global -> _updateType builds but doesn't render anything.)

The comment there says it was already broken on material system? On my end it was working fine so I can't confirm if there's any issue with it on master right now.

[slipher]

It was broken but #1704 fixed it. It works on master.

[VReaperV]

It was broken but #1704 fixed it. It works on master.

Not sure what the issue is. I can't reproduce it on my end, and there don't seem to be any depth writes after glTextureBarrier().

[slipher]

The depth texture is all garbage all the time, as if it's not hooked up properly. It's still garbage if I set r_materialSystemSkip 1. It's still garbage with r_drawWorld 0 and nothing being rendered.

By the way, I realized you can make a depth texture visualization with just a q3shader, no GLSL required:

depthvis {
    {
        map _white
        depthFade 600
        blendFunc GL_SRC_ALPHA GL_ZERO
    }
}

[slipher]

Forgot screenshot

[VReaperV]

Hmm, the only thing I could think of is it has something to do with the textures being bindless. This is on AMD + Mesa, right? It might have the same cause as the broken occlusion culling reported there ~1 year ago.

[slipher]

This is on AMD + Mesa, right?

Yes

It might have the same cause as the broken occlusion culling reported there ~1 year ago.

On master if I turn on occlusion culling, it segfaults immediately.

[VReaperV]

On master if I turn on occlusion culling, it segfaults immediately.

Is the segfault coming from daemon? I don't get any on master.

[slipher]

I have provided a stack trace in #1724

[slipher]

Hmm, the only thing I could think of is it has something to do with the textures being bindless.

That's true, just r_preferBindlessTextures is enough to trigger the bug.

[VReaperV]

Hmm, the only thing I could think of is it has something to do with the textures being bindless.

That's true, just r_preferBindlessTextures is enough to trigger the bug.

Even with the fix from #1725?

[VReaperV]

It might that the driver recognises that the depth map handle is in the buffer (which is interfaced in all shaders) and that breaks glTextureBarrier().

[VReaperV]

Actually no, there is a missing texture barrier, before depthtile.

[VReaperV]

Added a fix for that now.

[slipher]

I still get this with bindless textures

[VReaperV]

I see. One more possible workaround is to special-case the depth map, so it never goes into the buffer on AMD + Mesa.

[VReaperV]

I still get this with bindless textures

I added a workaround for AMD/Mesa.

[VReaperV]

CI failure is unrelated.

[slipher]

Now there is a weird bug where polygons with depth fade are drawn back-faced or with reverse culling. So for example rifle smoke and acid tube acid are invisible. You can see it by using /testshader and going to the other side.

[slipher]

Now there is a weird bug where polygons with depth fade are drawn back-faced or with reverse culling. So for example rifle smoke and acid tube acid are invisible. You can see it by using /testshader and going to the other side.

This happens iff bindless textures are used.

[VReaperV]

Now there is a weird bug where polygons with depth fade are drawn back-faced or with reverse culling. So for example rifle smoke and acid tube acid are invisible. You can see it by using /testshader and going to the other side.

Works fine for me. You can report it to Mesa, I don't see where the issue might be.

[slipher]

If we implement #1783 we could try activating it for drivers/hardware affected by depth texture problems as a workaround.

[slipher]

I wanted to see if the changes from #1814 had any effect on the issues here. So I made an attempt to rebase the PR so that each commits builds and runs - see the slipher/pushbuffer-rebase branch. (I had to squash several commits together because none of them would build without major surgery.)

I still get the problem that when bindless textures are enabled, depth fade and motion blur shaders produce noise. However, there is now an available workaround in setting r_readonlyDepthBuffer 2. The existing Add a workaround for AMD/Mesa driver bug with bindless on depth target commit didn't work for me, so maybe that could be used instead.

I also uncovered another issue: when disabling r_arb_direct_state_access (and hence push buffers), the GLSL does not compile.

[VReaperV]

I also uncovered another issue: when disabling r_arb_direct_state_access (and hence push buffers), the GLSL does not compile.

Fixed.

[VReaperV]

I've removed the previous workaround commit since it's not working.