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

1 files changed, 8 insertions, 8 deletions

diff --git a/src/gallium/auxiliary/draw/draw_pipe_clip.c b/src/gallium/auxiliary/draw/draw_pipe_clip.c
index 77ccddac4ab..fa10f8efca2 100644
--- a/src/gallium/auxiliary/draw/draw_pipe_clip.c
+++ b/src/gallium/auxiliary/draw/draw_pipe_clip.c
@@ -113,6 +113,7 @@ static void interp( const struct clipper *clip,
 		    const struct vertex_header *in )
 {
    const unsigned nr_attrs = clip->stage.draw->vs.num_vs_outputs;
+   const unsigned pos_attr = clip->stage.draw->vs.position_output;
    unsigned j;
 
    /* Vertex header.
@@ -138,18 +139,17 @@ static void interp( const struct clipper *clip,
       const float *trans = clip->stage.draw->viewport.translate;
       const float oow = 1.0f / pos[3];
 
-      dst->data[0][0] = pos[0] * oow * scale[0] + trans[0];
-      dst->data[0][1] = pos[1] * oow * scale[1] + trans[1];
-      dst->data[0][2] = pos[2] * oow * scale[2] + trans[2];
-      dst->data[0][3] = oow;
+      dst->data[pos_attr][0] = pos[0] * oow * scale[0] + trans[0];
+      dst->data[pos_attr][1] = pos[1] * oow * scale[1] + trans[1];
+      dst->data[pos_attr][2] = pos[2] * oow * scale[2] + trans[2];
+      dst->data[pos_attr][3] = oow;
    }
 
    /* Other attributes
-    * Note: start at 1 to skip winpos (data[0]) since we just computed
-    * it above.
     */
-   for (j = 1; j < nr_attrs; j++) {
-      interp_attr(dst->data[j], t, in->data[j], out->data[j]);
+   for (j = 0; j < nr_attrs; j++) {
+      if (j != pos_attr)
+         interp_attr(dst->data[j], t, in->data[j], out->data[j]);
    }
 }