draw: don't assume vertex position is in data[0]

1 files changed, 11 insertions, 0 deletions

diff --git a/src/gallium/auxiliary/draw/draw_vs.c b/src/gallium/auxiliary/draw/draw_vs.c
index 979f9864fdb..978954e91c9 100644
--- a/src/gallium/auxiliary/draw/draw_vs.c
+++ b/src/gallium/auxiliary/draw/draw_vs.c
@@ -85,6 +85,16 @@ draw_create_vertex_shader(struct draw_context *draw,
       }
    }
 
+   if (vs)
+   {
+      uint i;
+      for (i = 0; i < vs->info.num_outputs; i++) {
+         if (vs->info.output_semantic_name[i] == TGSI_SEMANTIC_POSITION &&
+             vs->info.output_semantic_index[i] == 0)
+            vs->position_output = i;
+      }
+   }
+
    assert(vs);
    return vs;
 }
@@ -100,6 +110,7 @@ draw_bind_vertex_shader(struct draw_context *draw,
    {
       draw->vs.vertex_shader = dvs;
       draw->vs.num_vs_outputs = dvs->info.num_outputs;
+      draw->vs.position_output = dvs->position_output;
       dvs->prepare( dvs, draw );
    }
    else {