https://bugs.freedesktop.org/show_bug.cgi?id=53884

Bug #: 53884 Summary: gl_FragCoord gets corrupted in some camera angles Classification: Unclassified Product: Mesa Version: 8.0 Platform: x86-64 (AMD64) OS/Version: Linux (All) Status: NEW Severity: normal Priority: medium Component: Drivers/Gallium/r600 AssignedTo: dri-devel@lists.freedesktop.org ReportedBy: curaga@operamail.com

Created attachment 65891 --> https://bugs.freedesktop.org/attachment.cgi?id=65891 Screenshot of the issue, bad camera angle

In certain camera angles, gl_FragCoord.xy seem to have bogus/corrupted values.

I tried to make a simple example but couldn't, so uploading an apitrace of the bigger app and screenshots. The apitrace is 60mb XZ-compressed, that's why the need to use a third-party service - upload limits here.

This shader:

void main() { gl_FragColor = vec4(gl_FragCoord.xy / vec2(640, 480), 0.0, 0.0); }

should always create values from 0 to 1 in a window of that size. In the apitrace the only difference is that the size is passed in an uniform.

This bug happens on both r600g and llvmpipe. I didn't have the patience to wait for softpipe to render it. I don't have anything else on this machine to compare to (swrast, blobs).

Mesa 8.0.3 Linux 3.2.23