i965: fix transform feedback with primitive restart

When querying GL_PRIMITIVES_GENERATED, if primitive restart
is also used, then take the software primitive restart
path so GL_PRIMITIVES_GENERATED is returned correctly.

GL_TRANSFORM_FEEDBACK_PRIMITIVES_WRITTEN is also updated
since it will also affected by the same issue.

As noted in brw_primitive_restart.c, with further work we
should be able to move this situation back to a hardware
handled path.

Signed-off-by: Jordan Justen <jordan.l.justen@intel.com>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>

1 files changed, 12 insertions, 0 deletions

diff --git a/src/mesa/drivers/dri/i965/brw_primitive_restart.c b/src/mesa/drivers/dri/i965/brw_primitive_restart.c
index 962ff18..02deba4 100644
--- a/src/mesa/drivers/dri/i965/brw_primitive_restart.c
+++ b/src/mesa/drivers/dri/i965/brw_primitive_restart.c
@@ -69,6 +69,18 @@ can_cut_index_handle_prims(struct gl_context *ctx,
                            GLuint nr_prims,
                            const struct _mesa_index_buffer *ib)
 {
+   struct brw_context *brw = brw_context(ctx);
+
+   if (brw->sol.counting_primitives_generated ||
+       brw->sol.counting_primitives_written) {
+      /* Counting primitives generated in hardware is not currently
+       * supported, so take the software path. We need to investigate
+       * the *_PRIMITIVES_COUNT registers to allow this to be handled
+       * entirely in hardware.
+       */
+      return false;
+   }
+
    if (!can_cut_index_handle_restart_index(ctx, ib)) {
       /* The primitive restart index can't be handled, so take
        * the software path