st/mesa: redefine mapping from VARYING_SLOT_TEXi/PNTC/VARi to TGSI GENERIC[i]

Generic varyings in TGSI were based on the value of VARYING_SLOT_TEX0, so VAR0
was always GENERIC[22] (with tessellation patches). Some drivers might not
be able to cope with that.

This commit defines a proper mapping, so that PNTC is GENERIC[8] and VAR0 is
GENERIC[9].

Reviewed-by: Brian Paul <[email protected]>

1 files changed, 25 insertions, 0 deletions

diff --git a/src/mesa/state_tracker/st_program.h b/src/mesa/state_tracker/st_program.h
index 9a5b6a847a5..cf1b40a55fc 100644
--- a/src/mesa/state_tracker/st_program.h
+++ b/src/mesa/state_tracker/st_program.h
@@ -270,6 +270,31 @@ st_reference_fragprog(struct st_context *st,
                            (struct gl_program *) prog);
 }
 
+/**
+ * This defines mapping from Mesa VARYING_SLOTs to TGSI GENERIC slots.
+ */
+static INLINE unsigned
+st_get_generic_varying_index(struct st_context *st, GLuint attr)
+{
+   if (attr >= VARYING_SLOT_VAR0) {
+      if (st->needs_texcoord_semantic)
+         return attr - VARYING_SLOT_VAR0;
+      else
+         return 9 + (attr - VARYING_SLOT_VAR0);
+   }
+   if (attr == VARYING_SLOT_PNTC) {
+      assert(!st->needs_texcoord_semantic);
+      return 8;
+   }
+   if (attr >= VARYING_SLOT_TEX0 && attr <= VARYING_SLOT_TEX7) {
+      assert(!st->needs_texcoord_semantic);
+      return attr - VARYING_SLOT_TEX0;
+   }
+
+   assert(0);
+   return 0;
+}
+
 
 extern struct st_vp_variant *
 st_get_vp_variant(struct st_context *st,