OpenGL & Vulkan

[rdb]

Users of several games using our engine have reported that surfaces are flickering using the Radeon RX 5700 XT.  I have traced this down to the use of GL_BGRA as first argument to glColorPointer calls, which causes it to apparently sample garbled data.  This occurs both with the fixed-function pipeline, as well as with shaders that use gl_Color.  It does not seem to occur for glVertexAttribPointer.

I captured an apitrace file that can be replayed using qapitrace or glretrace to reproduce the issue.  The last few frames show flickering white text (text rendering is grouped under "wglGraphicsWindow window1" > "render2d"), which should instead be continuously white and clearly visible, as it is on other cards:

http://rdb.name/amd-rdna-bug.trace

Avoiding use of GL_BGRA works around the issue for us.  Let me know if I can provide any additional assistance.

This is a regression: drivers 20.2.1, 20.2.2, 20.3.1, 20.4.1, and 20.4.2 do not exhibit the issue, 20.5.1 through 21.3.1 (latest) do.

[elstaci]

Deleted my answer since Moderator Dipak moved the thread to OpenGL directly.

[dipak]

Hi @rdb  ,

I've whitelisted you and moved this post to the OpenGL forum.

Thank you @elstaci for your help.

Thanks.

[rdb]

Thanks for moving the post and for the whitelist.  I've edited my original post with some information about the affected driver version.