mesa: Expose GLSL interpolation qualifiers in gl_fragment_program.

This patch makes GLSL interpolation qualifiers visible to drivers via
the array InterpQualifier[] in gl_fragment_program, so that they can
easily be used by driver back-ends to select the correct interpolation
mode.

Previous to this patch, the GLSL compiler was using the enum
ir_variable_interpolation to represent interpolation types.  Rather
than make a duplicate enum in core mesa to represent the same thing, I
moved the enum into mtypes.h and renamed it to be more consistent with
the other enums defined there.

Reviewed-by: Brian Paul <[email protected]>
Reviewed-by: Kenneth Graunke <[email protected]>
Reviewed-by: Eric Anholt <[email protected]>

3 files changed, 21 insertions, 2 deletions

diff --git a/src/mesa/main/mtypes.h b/src/mesa/main/mtypes.h
index 4117686414e..9410e3ff67a 100644
--- a/src/mesa/main/mtypes.h
+++ b/src/mesa/main/mtypes.h
@@ -1790,6 +1790,18 @@ typedef enum
 } gl_system_value;
 
 
+/**
+ * The possible interpolation qualifiers that can be applied to a fragment
+ * shader input in GLSL.
+ */
+enum glsl_interp_qualifier
+{
+   INTERP_QUALIFIER_SMOOTH,
+   INTERP_QUALIFIER_FLAT,
+   INTERP_QUALIFIER_NOPERSPECTIVE
+};
+
+
 /** Vertex and fragment instructions */
 struct prog_instruction;
 struct gl_program_parameter_list;
@@ -1890,6 +1902,13 @@ struct gl_fragment_program
    GLboolean OriginUpperLeft;
    GLboolean PixelCenterInteger;
    enum gl_frag_depth_layout FragDepthLayout;
+
+   /**
+    * GLSL interpolation qualifier associated with each fragment shader input.
+    * For inputs that do not have an interpolation qualifier specified in
+    * GLSL, the value is INTERP_QUALIFIER_SMOOTH.
+    */
+   enum glsl_interp_qualifier InterpQualifier[FRAG_ATTRIB_MAX];
 };
 
 
diff --git a/src/mesa/program/ir_to_mesa.cpp b/src/mesa/program/ir_to_mesa.cpp
index bdbb6b93838..93563bdaa5b 100644
--- a/src/mesa/program/ir_to_mesa.cpp
+++ b/src/mesa/program/ir_to_mesa.cpp
@@ -3191,7 +3191,7 @@ get_mesa_program(struct gl_context *ctx,
    prog->Instructions = mesa_instructions;
    prog->NumInstructions = num_instructions;
 
-   do_set_program_inouts(shader->ir, prog);
+   do_set_program_inouts(shader->ir, prog, shader->Type == GL_FRAGMENT_SHADER);
    count_resources(prog);
 
    check_resources(ctx, shader_program, prog);
diff --git a/src/mesa/state_tracker/st_glsl_to_tgsi.cpp b/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
index 145bd7dcd0c..67a1b513bda 100644
--- a/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
+++ b/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
@@ -4966,7 +4966,7 @@ get_mesa_program(struct gl_context *ctx,
    prog->Instructions = NULL;
    prog->NumInstructions = 0;
 
-   do_set_program_inouts(shader->ir, prog);
+   do_set_program_inouts(shader->ir, prog, shader->Type == GL_FRAGMENT_SHADER);
    count_resources(v, prog);
 
    check_resources(ctx, shader_program, v, prog);