glsl: rewrite clip/cull distance lowering pass

The last version of this broke clipping, and I had to spend
sometime getting this working properly.

I had to introduce a third pass to count the clip/cull totals,
all due to one messy corner case. We have a piglit test
tes-input-gl_ClipDistance.shader_test
that doesn't actually output the clip distances, it just passes
them like a varying from TCS->TES, the older lowering pass worked
but to lower clip/cull we need to know the total number of clip+culls
used to defined the new variable correctly, and to offset culls
properly.

This adds an extra pass that works out the sizes for clip/cull,
then lowers gl_ClipDistance then gl_CullDistance into the new
gl_ClipDistanceMESA.

The pass checks using the fixed array sizes code if they array
has been referenced, or is actually never used, and ignores
it in the latter case.

Reviewed-by: Ilia Mirkin <imirkin@alum.mit.edu>
Signed-off-by: Dave Airlie <airlied@redhat.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/src/compiler/glsl/linker.cpp b/src/compiler/glsl/linker.cpp
index f4d443b..ca2f060 100644
--- a/src/compiler/glsl/linker.cpp
+++ b/src/compiler/glsl/linker.cpp
@@ -4663,7 +4663,7 @@ link_shaders(struct gl_context *ctx, struct gl_shader_program *prog)
 	 goto done;
 
       if (ctx->Const.ShaderCompilerOptions[i].LowerCombinedClipCullDistance) {
-         lower_clip_distance(prog->_LinkedShaders[i]);
+         lower_clip_cull_distance(prog, prog->_LinkedShaders[i]);
       }
 
       if (ctx->Const.LowerTessLevel) {