[Mesa-dev] [PATCH] i965: Enable EWA anisotropic filtering algorithm

Ian Romanick idr at freedesktop.org
Tue Mar 4 01:08:05 PST 2014


From: Ian Romanick <ian.d.romanick at intel.com>

Volume 4, part 1 of the Ivybridge PRM says, "Generally, the EWA
approximation algorithm results in higher image quality than the legacy
algorithm."  Using a classic anisotropic filtering "tunnel" demo, it
appears that there is *no* anisotropic filtering on IVB without this bit
set.

Signed-off-by: Ian Romanick <ian.d.romanick at intel.com>
Cc: Eero Tamminen <eero.t.tamminen at intel.com>
---
 src/mesa/drivers/dri/i965/gen7_sampler_state.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/mesa/drivers/dri/i965/gen7_sampler_state.c b/src/mesa/drivers/dri/i965/gen7_sampler_state.c
index 968c410..709a783 100644
--- a/src/mesa/drivers/dri/i965/gen7_sampler_state.c
+++ b/src/mesa/drivers/dri/i965/gen7_sampler_state.c
@@ -82,6 +82,7 @@ gen7_update_sampler_state(struct brw_context *brw, int unit, int ss_index,
    if (gl_sampler->MaxAnisotropy > 1.0) {
       sampler->ss0.min_filter = BRW_MAPFILTER_ANISOTROPIC;
       sampler->ss0.mag_filter = BRW_MAPFILTER_ANISOTROPIC;
+      sampler->ss0.aniso_algorithm = 1;
 
       if (gl_sampler->MaxAnisotropy > 2.0) {
 	 sampler->ss3.max_aniso = MIN2((gl_sampler->MaxAnisotropy - 2) / 2,
-- 
1.8.1.4



More information about the mesa-dev mailing list