Minimap broken

[fabio]

The circular minimaps are broken here since a while. Example on current build from svn on Linux with Death Canion:

EDIT: this is a mesa (Linux) driver problem: see this bug for more info: ​https://bugs.freedesktop.org/show_bug.cgi?id=36762

[Philip Taylor]

I guess "a while" may have been r9139. This looks like a z-ordering problem, but it works fine for me and I don't see why it'd be different for you :-(

What drivers are these? Is it the same regardless of renderpath/shadows/fancywater, and regardless of any scrolling on the map?

[fabio]

Replying to Philip:

I guess "a while" may have been r9139. This looks like a z-ordering problem, but it works fine for me and I don't see why it'd be different for you :-(

What drivers are these? Is it the same regardless of renderpath/shadows/fancywater, and regardless of any scrolling on the map?

Broken with r300g (git master and git 7.9 branch) and every combination of renderpath/shadows/fancywater.

Works fine with old r300 and llvmpipe.

[fabio]

I reverted r9139 and indeed the minimap worked again. However, if you think the current 0ad code is fine, and indeed it only breaks gallium r300, maybe it's better to leave this as is. In this case I'll open a bug report against the r300 gallium driver.

[Philip Taylor]

I don't see anything obviously wrong or particularly unusual with the current minimap code, and haven't seen problems in any other drivers, so I guess it's most likely that it is a driver bug.

(Only about 0.5% of users seem to be on r300g so I don't think this is critical for the release. But it's probably good to keep the ticket open for a while to track any driver bug reports, and maybe add workarounds to our code depending on what the bug is.)

[fabio]

OK, I reported the bug here: ​https://bugs.freedesktop.org/show_bug.cgi?id=36762

Please avoid adding the workaround until the r300g driver is fixed, so that mesa developers can have a test case for it.