svga: fix shadow comparison failures

In some cases, We do shadow comparison cases in the fragment shader
instead of with texture sampler state.  But when we do so, we must
disable the shadow comparison test in the sampler state.  As it
was, we were doing the comparison twice, which resulted in nonsense.
Also, we had the texcoord and texel value swapped in the comparison
instruction.

Fixes about 38 Piglit tex-miplevel-selection tests.

Reviewed-by: Neha Bhende <[email protected]>
Reviewed-by: Charmaine Lee <[email protected]>

1 files changed, 5 insertions, 0 deletions

diff --git a/src/gallium/drivers/svga/svga_shader.h b/src/gallium/drivers/svga/svga_shader.h
index dc462c94af6..70d12469827 100644
--- a/src/gallium/drivers/svga/svga_shader.h
+++ b/src/gallium/drivers/svga/svga_shader.h
@@ -158,6 +158,11 @@ struct svga_shader_variant
    /** Is the color output just a constant value? (fragment shader only) */
    boolean constant_color_output;
 
+   /** Bitmask indicating which texture units are doing the shadow
+    * comparison test in the shader rather than the sampler state.
+    */
+   unsigned fs_shadow_compare_units;
+
    /** For FS-based polygon stipple */
    unsigned pstipple_sampler_unit;