From: Paul Berry Date: Wed, 27 Nov 2013 15:43:03 +0000 (-0800) Subject: i965/gen6: Fix multisample resolve blits for luminance/intensity 32F formats. X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=c4cf487315f1f5375534f1677177983fa496d577;p=mesa.git i965/gen6: Fix multisample resolve blits for luminance/intensity 32F formats. On gen6, multisamble resolve blits use the SAMPLE message to blend together the 4 samples for each texel. For some reason, SAMPLE doesn't blend together the proper samples when the source format is L32_FLOAT or I32_FLOAT, resulting in blocky artifacts. To work around this problem, sample from the source surface using R32_FLOAT. This shouldn't affect rendering correctness, because when doing these resolve blits, the destination format is R32_FLOAT, so the channel replication done by L32_FLOAT and I32_FLOAT is unnecessary. Fixes piglit tests on Sandy Bridge: - spec/ARB_texture_float/multisample-formats 2 GL_ARB_texture_float - spec/ARB_texture_float/multisample-formats 4 GL_ARB_texture_float No piglit regressions on Sandy Bridge. Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=70601 Cc: Kenneth Graunke Cc: mesa-stable@lists.freedesktop.org Reviewed-by: Kenneth Graunke --- diff --git a/src/mesa/drivers/dri/i965/brw_blorp_blit.cpp b/src/mesa/drivers/dri/i965/brw_blorp_blit.cpp index 2d2edc1649c..9c48eacef5d 100644 --- a/src/mesa/drivers/dri/i965/brw_blorp_blit.cpp +++ b/src/mesa/drivers/dri/i965/brw_blorp_blit.cpp @@ -2099,6 +2099,21 @@ brw_blorp_blit_params::brw_blorp_blit_params(struct brw_context *brw, src.brw_surfaceformat = dst.brw_surfaceformat; } + /* When doing a multisample resolve of a GL_LUMINANCE32F or GL_INTENSITY32F + * texture, the above code configures the source format for L32_FLOAT or + * I32_FLOAT, and the destination format for R32_FLOAT. On Sandy Bridge, + * the SAMPLE message appears to handle multisampled L32_FLOAT and + * I32_FLOAT textures incorrectly, resulting in blocky artifacts. So work + * around the problem by using a source format of R32_FLOAT. This + * shouldn't affect rendering correctness, since the destination format is + * R32_FLOAT, so only the contents of the red channel matters. + */ + if (brw->gen == 6 && src.num_samples > 1 && dst.num_samples <= 1 && + src_mt->format == dst_mt->format && + dst.brw_surfaceformat == BRW_SURFACEFORMAT_R32_FLOAT) { + src.brw_surfaceformat = dst.brw_surfaceformat; + } + use_wm_prog = true; memset(&wm_prog_key, 0, sizeof(wm_prog_key));