i965: fix EXT_provoking_vertex support

This didn't work for quad/quadstrips at all, and for all other primitive types
it only worked when they were unclipped.
Fix up the former in gs stage (could probably do without these changes and
instead set QuadsFollowProvokingVertexConvention to false), and the rest in
clip stage.

1 files changed, 1 insertions, 0 deletions

diff --git a/src/mesa/drivers/dri/i965/brw_clip.c b/src/mesa/drivers/dri/i965/brw_clip.c
index 20a927cf38..f45dcf8282 100644
--- a/src/mesa/drivers/dri/i965/brw_clip.c
+++ b/src/mesa/drivers/dri/i965/brw_clip.c
@@ -156,6 +156,7 @@ static void upload_clip_prog(struct brw_context *brw)
    key.attrs = brw->vs.prog_data->outputs_written;
    /* _NEW_LIGHT */
    key.do_flat_shading = (ctx->Light.ShadeModel == GL_FLAT);
+   key.pv_first = (ctx->Light.ProvokingVertex == GL_FIRST_VERTEX_CONVENTION);
    /* _NEW_TRANSFORM */
    key.nr_userclip = brw_count_bits(ctx->Transform.ClipPlanesEnabled);