glsl: Optionally lower TES gl_PatchVerticesIn to a uniform.

i965 has no special hardware for this, so we need to pass this value in
as a uniform (unless the TES is linked against a TCS, in which case the
linker can just replace this with a constant).

Signed-off-by: Kenneth Graunke <[email protected]>
Reviewed-by: Alejandro Piñeiro <[email protected]>
Cc: [email protected]

3 files changed, 9 insertions, 0 deletions

diff --git a/src/mesa/main/mtypes.h b/src/mesa/main/mtypes.h
index 471d41d4435..85ef22db9c2 100644
--- a/src/mesa/main/mtypes.h
+++ b/src/mesa/main/mtypes.h
@@ -3762,6 +3762,7 @@ struct gl_constants
    GLuint MaxTessPatchComponents;
    GLuint MaxTessControlTotalOutputComponents;
    bool LowerTessLevel; /**< Lower gl_TessLevel* from float[n] to vecn? */
+   bool LowerTESPatchVerticesIn; /**< Lower gl_PatchVerticesIn to a uniform */
    bool PrimitiveRestartForPatches;
    bool LowerCsDerivedVariables;    /**< Lower gl_GlobalInvocationID and
                                      *   gl_LocalInvocationIndex based on
diff --git a/src/mesa/program/prog_statevars.c b/src/mesa/program/prog_statevars.c
index 27ff3339eaf..23e3015146f 100644
--- a/src/mesa/program/prog_statevars.c
+++ b/src/mesa/program/prog_statevars.c
@@ -598,6 +598,13 @@ _mesa_fetch_state(struct gl_context *ctx, const gl_state_index state[],
          }
          return;
 
+      case STATE_TES_PATCH_VERTICES_IN:
+         if (ctx->TessCtrlProgram._Current)
+            val[0].i = ctx->TessCtrlProgram._Current->VerticesOut;
+         else
+            val[0].i = ctx->TessCtrlProgram.patch_vertices;
+         return;
+
       /* XXX: make sure new tokens added here are also handled in the 
        * _mesa_program_state_flags() switch, below.
        */
diff --git a/src/mesa/program/prog_statevars.h b/src/mesa/program/prog_statevars.h
index 6333e632816..4b27527b1f9 100644
--- a/src/mesa/program/prog_statevars.h
+++ b/src/mesa/program/prog_statevars.h
@@ -128,6 +128,7 @@ typedef enum gl_state_index_ {
    STATE_PT_BIAS,               /**< Pixel transfer RGBA bias */
    STATE_FB_SIZE,               /**< (width-1, height-1, 0, 0) */
    STATE_FB_WPOS_Y_TRANSFORM,   /**< (1, 0, -1, height) if a FBO is bound, (-1, height, 1, 0) otherwise */
+   STATE_TES_PATCH_VERTICES_IN, /**< gl_PatchVerticesIn for TES (integer) */
    STATE_INTERNAL_DRIVER	/* first available state index for drivers (must be last) */
 } gl_state_index;