Metal: example-01-helloworld corrupted render when MSAA is enabled
rogual opened this issue · comments
Describe the bug
With MSAA on, the Hello World example renders with a bright pink background on my M2 Mac, and the imgui window disappears. Strangely enough, if I capture a frame with the Metal graphics debugger, it shows as normal in there. No errors are reported either.
To Reproduce
Steps to reproduce the behavior:
- Run Hello World example
- Press F8 to turn on MSAA
Expected behavior
The example should display as normal
Screenshots
Additional context
MacBook Pro
Apple M2 Max
OS: 13.5 (22G74)
Chipset Model: Apple M2 Max
Type: GPU
Bus: Built-In
Total Number of Cores: 30
Vendor: Apple (0x106b)
Metal Support: Metal 3
Hm, this is suspicious. That's a non-MSAA frame on the left, and MSAA (pink frame) on the right.
I notice the dependency between submit and blitRender is a dashed line in the MSAA frame, which means synchronization only (no data transfer). So the frame isn't being transferred between submit and blitRender passes? I hope I have that right.
It looks like bgfx is storing to "Color 0 Resolve" in the submit pass, but trying to load from "Color 0" in the blitRender pass.