mesa: Add GL and GLSL plumbing for ARB_post_depth_coverage for i965 (gen9+).

This extension allows the fragment shader to control whether values in
gl_SampleMaskIn[] reflect the coverage after application of the early
depth and stencil tests.

Signed-off-by: Plamena Manolova <[email protected]>
Reviewed-by: Chris Forbes <[email protected]>

1 files changed, 18 insertions, 0 deletions

diff --git a/src/compiler/glsl/glsl_parser.yy b/src/compiler/glsl/glsl_parser.yy
index 0c3781c3361..09b7e79c40b 100644
--- a/src/compiler/glsl/glsl_parser.yy
+++ b/src/compiler/glsl/glsl_parser.yy
@@ -1392,6 +1392,24 @@ layout_qualifier_id:
 
             $$.flags.q.early_fragment_tests = 1;
          }
+
+         if (!$$.flags.i &&
+             match_layout_qualifier($1, "post_depth_coverage", state) == 0) {
+            if (state->stage != MESA_SHADER_FRAGMENT) {
+               _mesa_glsl_error(& @1, state,
+                                "post_depth_coverage layout qualifier only "
+                                "valid in fragment shaders");
+            }
+
+            if (state->ARB_post_depth_coverage_enable) {
+               $$.flags.q.post_depth_coverage = 1;
+            } else {
+               _mesa_glsl_error(& @1, state,
+                                "post_depth_coverage layout qualifier present, "
+                                "but the GL_ARB_post_depth_coverage extension "
+                                "is not enabled.");
+            }
+         }
       }
 
       /* Layout qualifiers for tessellation evaluation shaders. */