llvmpipe: do final the pixel in/out triangle test in the fragment shader

The test to determine which of the pixels in a 2x2 quad is now done in
the fragment shader rather than in the calling C code.  This is a little
faster but there's a few more things to do.

Note that the step[] array elements are in a different order now.  Rather
than being in row-major order for the 4x4 grid, they're in "quad-major"
order.  The setup of the step arrays is a little more complicated now.
So is the course/intermediate tile test code, but some lookup tables
help with that.

Next steps:
 - early-cull 2x2 quads which are totally outside the triangle.
 - skip the in/out test for fully contained quads
 - make the in/out comparison code tighter/faster.

1 files changed, 5 insertions, 6 deletions

diff --git a/src/gallium/drivers/llvmpipe/lp_rast.h b/src/gallium/drivers/llvmpipe/lp_rast.h
index 2dd0193d8d..46e22f69a6 100644
--- a/src/gallium/drivers/llvmpipe/lp_rast.h
+++ b/src/gallium/drivers/llvmpipe/lp_rast.h
@@ -80,6 +80,9 @@ struct lp_rast_shader_inputs {
    float (*a0)[4];
    float (*dadx)[4];
    float (*dady)[4];
+
+   /* edge/step info for 3 edges and 4x4 block of pixels */
+   int ALIGN16_ATTRIB step[3][16];
 };
 
 
@@ -117,14 +120,10 @@ struct lp_rast_triangle {
    int dx31;
 
    /* edge function values at minx,miny ?? */
-   int c1;
-   int c2;
-   int c3;
-
-   int step[3][16];
+   int c1, c2, c3;
 
    /* inputs for the shader */
-   struct lp_rast_shader_inputs inputs;
+   struct lp_rast_shader_inputs ALIGN16_ATTRIB inputs;
 };