mesa: glGetProgramResourceLocationIndex

Patch adds required helper functions to shaderapi.h and
the actual implementation.

The added functionality can be tested by tests for following
functions that are refactored by later patches:

   GetFragDataIndex

v2: return -1 if output not referenced by fragment stage
    (Ilia Mirkin)

Signed-off-by: Tapani Pälli <[email protected]>
Reviewed-by: Martin Peres <[email protected]>

1 files changed, 18 insertions, 0 deletions

diff --git a/src/mesa/main/shader_query.cpp b/src/mesa/main/shader_query.cpp
index f50ceb6a56b..8b2281ddd5c 100644
--- a/src/mesa/main/shader_query.cpp
+++ b/src/mesa/main/shader_query.cpp
@@ -821,3 +821,21 @@ _mesa_program_resource_location(struct gl_shader_program *shProg,
 
    return program_resource_location(shProg, res, name);
 }
+
+/**
+ * Function implements following index queries:
+ *    glGetFragDataIndex
+ */
+GLint
+_mesa_program_resource_location_index(struct gl_shader_program *shProg,
+                                      GLenum interface, const char *name)
+{
+   struct gl_program_resource *res =
+      _mesa_program_resource_find_name(shProg, interface, name);
+
+   /* Non-existent variable or resource is not referenced by fragment stage. */
+   if (!res || !(res->StageReferences & (1 << MESA_SHADER_FRAGMENT)))
+      return -1;
+
+   return RESOURCE_VAR(res)->data.index;
+}