Created attachment 41478 [details]
Screenshot of bug in Amnesia
Some games have some sort of visible wireframe, or an outline visible when r300g is used (softpipe does not have this problem). I'm pretty sure this is a known bug, but I haven't found any open bug reports about it.
This bug is very noticeable in the game Amnesia (where the screenshot is from).
-- system architecture: 32-bit
-- Linux distribution: Debian unstable
-- GPU: RV570
-- Model: Asus EAX1950Pro 256MB
-- Display connector: DVI
-- xf86-video-ati: e9928fe036e9382fd7bc353f3f05531445f08977
-- xserver: 22.214.171.1242 (1.9.1 RC 2)
-- mesa: b832ae8a4a77563c50a6e82c49b4732f6a0dbf11
-- drm: 2.4.22
-- kernel: 2.6.36
Is it known what function/effect the bug is in? If not, considering how prevalent this is in Amnesia, maybe Edward Rudd could shed some light on this?
This bug is r500-only as far as I can tell.
I have just found a way to trigger it very easily: enable offset mapping in nexuiz. If you disable it, the problem will go away. Given this fact, I believe it's a bug in our r500 fragment shader backend.
I have a similar problem with sauerbraten on my RV530, with both r300 and r300g, see also bug #25710.
Commit 6da4866ffdb19315bbb48f6778d1a5297b842a77 fixes it here. Closing.