<html> <head> <base href="https://bugs.freedesktop.org/"> </head> <body> <div> <a class="bz_bug_link bz_status_REOPENED " title="REOPENED - Stellaris - colored overlay of sectors doesn't render on i965" href="https://bugs.freedesktop.org/show_bug.cgi?id=95530#c11">Comment # 11</a> on <a class="bz_bug_link bz_status_REOPENED " title="REOPENED - Stellaris - colored overlay of sectors doesn't render on i965" href="https://bugs.freedesktop.org/show_bug.cgi?id=95530">bug 95530</a> from <a class="email" href="mailto:jakub+mesa@streamcomputing.eu" title="Jakub Szuppe <jakub+mesa@streamcomputing.eu>"> Jakub Szuppe</a> <pre>Sectors have "noisy" borders and very low transparency on i965 driver (Mesa 17.1.0-devel (git-d5ee55f)). Other Mesa drivers (llvmpipe and radeonsi) work correctly. How it looks like on i965: <a href="https://drive.google.com/open?id=0B1fY17pW39ZeWUoxVXJWUU42dFk">https://drive.google.com/open?id=0B1fY17pW39ZeWUoxVXJWUU42dFk</a> How it should: <a href="https://drive.google.com/open?id=0B1fY17pW39ZeUGhQdmRTUS1UVWc">https://drive.google.com/open?id=0B1fY17pW39ZeUGhQdmRTUS1UVWc</a> These overlays are rendered using render-to-texture in the call 2149486: <a href="https://drive.google.com/open?id=0B1fY17pW39ZedlFDREwwSFB6Nzg">https://drive.google.com/open?id=0B1fY17pW39ZedlFDREwwSFB6Nzg</a> The program 706 (a fragment shader 708, created in 911931) uses two textures with glTexParameteri(target = GL_TEXTURE_2D, pname = GL_TEXTURE_MIN_FILTER, param = GL_NEAREST) glTexParameteri(target = GL_TEXTURE_2D, pname = GL_TEXTURE_MAG_FILTER, param = GL_NEAREST) These textures also have GL_TEXTURE_MAX_ANISOTROPY_EXT set to 16: glTexParameterf(target = GL_TEXTURE_2D, pname = GL_TEXTURE_MAX_ANISOTROPY_EXT, param = 16) Setting GL_TEXTURE_MAX_ANISOTROPY_EXT to 1 for both textures fixes the issue: <a href="https://drive.google.com/open?id=0B1fY17pW39Zec2pMa3dIN0Nobjg">https://drive.google.com/open?id=0B1fY17pW39Zec2pMa3dIN0Nobjg</a> I.e., GL_TEXTURE_MAX_ANISOTROPY_EXT disables GL_NEAREST, and because the shader highly depends on exact texel values (it calculates sums, maximum of values of the first texture, uses the second texture as a look-up table), the results have such a big difference. Here the code that disables GL_NEAREST in this case: <a href="https://cgit.freedesktop.org/mesa/mesa/tree/src/mesa/drivers/dri/i965/brw_sampler_state.c#n454">https://cgit.freedesktop.org/mesa/mesa/tree/src/mesa/drivers/dri/i965/brw_sampler_state.c#n454</a> We've found one issue with a proposed patch here: <a class="bz_bug_link bz_status_NEW " title="NEW - setting texture filtering to nearest has no effect when anisotropy is greater than 1" href="show_bug.cgi?id=91786">https://bugs.freedesktop.org/show_bug.cgi?id=91786</a> The patched driver produces correct results for both traces. Kind regards, Stream HPC Team <a href="https://streamhpc.com/">https://streamhpc.com/</a></pre> </div> <hr> You are receiving this mail because: <ul> <li>You are the QA Contact for the bug.</li> </ul> </body> </html>