Mesa (master): i965: Enable EWA anisotropic filtering algorithm

[Kenneth Graunke]

Module: Mesa
Branch: master
Commit: f74cf5f80ea6ea16abb38c28c2b4826b8559017b
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=f74cf5f80ea6ea16abb38c28c2b4826b8559017b

Author: Ian Romanick <ian.d.romanick at intel.com>
Date:   Tue Mar  4 11:08:05 2014 +0200

i965: Enable EWA anisotropic filtering algorithm

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>
Reviewed-by: Kenneth Graunke <kenneth at whitecape.org>

---

 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,