st/mesa: use shader stencil export to accelerate shader drawpixels.

If the pipe driver has shader stencil export we can accelerate DrawPixels
using it. It tries to pick an S8 texture and works its way to X24S8 and S8X24
if that isn't supported.

1 files changed, 9 insertions, 0 deletions

diff --git a/src/mesa/state_tracker/st_program.c b/src/mesa/state_tracker/st_program.c
index 18a7bbe0f9..733cdd0ac9 100644
--- a/src/mesa/state_tracker/st_program.c
+++ b/src/mesa/state_tracker/st_program.c
@@ -398,11 +398,20 @@ st_translate_fragment_program(struct st_context *st,
          outputsWritten &= ~(1 << FRAG_RESULT_DEPTH);
       }
 
+      if (outputsWritten & BITFIELD64_BIT(FRAG_RESULT_STENCIL)) {
+         fs_output_semantic_name[fs_num_outputs] = TGSI_SEMANTIC_STENCIL;
+         fs_output_semantic_index[fs_num_outputs] = 0;
+         outputMapping[FRAG_RESULT_STENCIL] = fs_num_outputs;
+         fs_num_outputs++;
+         outputsWritten &= ~(1 << FRAG_RESULT_STENCIL);
+      }
+
       /* handle remaning outputs (color) */
       for (attr = 0; attr < FRAG_RESULT_MAX; attr++) {
          if (outputsWritten & BITFIELD64_BIT(attr)) {
             switch (attr) {
             case FRAG_RESULT_DEPTH:
+            case FRAG_RESULT_STENCIL:
                /* handled above */
                assert(0);
                break;