<html> <head> <base href="https://bugs.freedesktop.org/"> </head> <body> <div> <a class="bz_bug_link bz_status_NEW " title="NEW - triangle clipping causes wrong vertex's attribute to be broadcasted for flat interpolation" href="https://bugs.freedesktop.org/show_bug.cgi?id=98846#c3">Comment # 3</a> on <a class="bz_bug_link bz_status_NEW " title="NEW - triangle clipping causes wrong vertex's attribute to be broadcasted for flat interpolation" href="https://bugs.freedesktop.org/show_bug.cgi?id=98846">bug 98846</a> from <a class="email" href="mailto:sroland@vmware.com" title="Roland Scheidegger <sroland@vmware.com>"> Roland Scheidegger</a> <pre>(In reply to Zebediah Figura from <a href="show_bug.cgi?id=98846#c2">comment #2</a>) > This also affects softpipe and llvmpipe. I'm not familiar with mesa, but I > think there are multiple places that do the wrong thing. For example, > do_clip_tri() in src/gallium/auxiliary/draw/draw_pipe_clip.c gets passed the > vertices in winding order, but it doesn't take that into account when > determining provoking vertex. > > If this should be split off to a separate bug, then I'll do so. > > This causes failures in Wine's conformance test suite, since we use > GL_FIRST_VERTEX_CONVENTION universally, and test flat shading with > GL_TRIANGLESTRIP and some vertices slightly clipped outside of the viewport. > Since our test suite is run in a virtual machine, it uses llvmpipe, and so > is affected by this bug. I suspect it's a different issue. For llvmpipe the piglit test you pointed out works just fine. (I have some suspicion for llvmpipe/softpipe it would make a difference if you use interpolation qualifier flat vs. shade model flat. See the FIXME in draw_pt_decompose.h - the order of decomposing should only be determined by flatshade_first, and not depend on if flatshade is actually active. But we need this to compensate for some bug elsewhere, apparently...)</pre> </div> <hr> You are receiving this mail because: <ul> <li>You are the assignee for the bug.</li> <li>You are the QA Contact for the bug.</li> </ul> </body> </html>