Here is a dff reproducing that issue (Dolphin’s equivalent of apitrace, too big to attach here): https://linkmauve.fr/files/zmm.dff.xz
This issue happens on Mesa a7b510f656dfbda0afb1de78926037a337449140, using Dolphin master, and isn’t present on either OpenGL/i965 on the same machine, or Vulkan/Nvidia/Windows from another tester.
This is on commit 88b5acfa09d4efa2aea1fc9cc4f8169a48c40286 btw, built yesterday, but has been happening for a while.
Oops, wrong bug report. ^^'
I’ve been able to test this one on bdw too and the bug was also present, but that was on an old 13.something Mesa, we’ve been unable to test on a newer Mesa.
I can’t reproduce this anymore, the dff renders fine on the same computer using Mesa 18.2.4.