llvmpipe: don't interpolate front face or prim id

The loop was iterating over all the fs inputs and setting them
to perspective interpolation, then after the loop we were
creating extra output slots with the correct interpolation. Instead
of injecting bogus extra outputs, just set the interpolation
on front face and prim id correctly when doing the initial scan
of fs inputs.

Signed-off-by: Zack Rusin <[email protected]>
Reviewed-by: Roland Scheidegger <[email protected]>
Reviewed-by: Jose Fonseca <[email protected]>
Reviewed-by: Brian Paul <[email protected]>

1 files changed, 13 insertions, 15 deletions

diff --git a/src/gallium/drivers/llvmpipe/lp_state_derived.c b/src/gallium/drivers/llvmpipe/lp_state_derived.c
index 5a51b50821e..8aee92b1b96 100644
--- a/src/gallium/drivers/llvmpipe/lp_state_derived.c
+++ b/src/gallium/drivers/llvmpipe/lp_state_derived.c
@@ -69,8 +69,8 @@ compute_vertex_info(struct llvmpipe_context *llvmpipe)
    vinfo->num_attribs = 0;
 
    vs_index = draw_find_shader_output(llvmpipe->draw,
-                                       TGSI_SEMANTIC_POSITION,
-                                       0);
+                                      TGSI_SEMANTIC_POSITION,
+                                      0);
 
    draw_emit_vertex_attr(vinfo, EMIT_4F, INTERP_PERSPECTIVE, vs_index);
 
@@ -89,12 +89,18 @@ compute_vertex_info(struct llvmpipe_context *llvmpipe)
          llvmpipe->color_slot[idx] = (int)vinfo->num_attribs;
       }
 
-      /*
-       * Emit the requested fs attribute for all but position.
-       */
-      draw_emit_vertex_attr(vinfo, EMIT_4F, INTERP_PERSPECTIVE, vs_index);
+      if (lpfs->info.base.input_semantic_name[i] == TGSI_SEMANTIC_FACE) {
+         llvmpipe->face_slot = vinfo->num_attribs;
+         draw_emit_vertex_attr(vinfo, EMIT_4F, INTERP_CONSTANT, vs_index);
+      } else if (lpfs->info.base.input_semantic_name[i] == TGSI_SEMANTIC_PRIMID) {
+         draw_emit_vertex_attr(vinfo, EMIT_4F, INTERP_CONSTANT, vs_index);
+      } else {
+         /*
+          * Emit the requested fs attribute for all but position.
+          */
+         draw_emit_vertex_attr(vinfo, EMIT_4F, INTERP_PERSPECTIVE, vs_index);
+      }
    }
-
    /* Figure out if we need bcolor as well.
     */
    for (i = 0; i < 2; i++) {
@@ -140,14 +146,6 @@ compute_vertex_info(struct llvmpipe_context *llvmpipe)
       llvmpipe->layer_slot = 0;
    }
 
-   /* Check for a fake front face for unfilled primitives*/
-   vs_index = draw_find_shader_output(llvmpipe->draw,
-                                      TGSI_SEMANTIC_FACE, 0);
-   if (vs_index >= 0) {
-      llvmpipe->face_slot = vinfo->num_attribs;
-      draw_emit_vertex_attr(vinfo, EMIT_4F, INTERP_CONSTANT, vs_index);
-   }
-
    draw_compute_vertex_size(vinfo);
    lp_setup_set_vertex_info(llvmpipe->setup, vinfo);
 }