Before, we weren't setting step rate so we got whatever old value happened to be lying around. This can lead to some interesting rendering errors. In particular, if you run the OpenGL ES CTS with dEQP-GLES3.functional.instanced.types.mat2x4 immediately followed by one of the dEQP-GLES3.functional.transform_feedback.* tests, the transform feedback test gets stale instancing data from the other test and fails. The only thing that is causing this to not be a problem today is that we use meta for clears and meta is setting up vertex buffers via the VBO or non-interleaved path and setting step_rate to 0 for us. When blorp depth/stencil clears are enabled, meta is no longer sitting between the two tests and the stale data starts causing noticeable problems.
Cc: "17.1" <mesa-sta...@lists.freedesktop.org> --- src/mesa/drivers/dri/i965/brw_draw_upload.c | 1 + 1 file changed, 1 insertion(+) diff --git a/src/mesa/drivers/dri/i965/brw_draw_upload.c b/src/mesa/drivers/dri/i965/brw_draw_upload.c index cf66770..05b6b1a 100644 --- a/src/mesa/drivers/dri/i965/brw_draw_upload.c +++ b/src/mesa/drivers/dri/i965/brw_draw_upload.c @@ -648,6 +648,7 @@ brw_prepare_vertices(struct brw_context *brw) buffer, interleaved); buffer->offset -= delta * interleaved; buffer->size += delta * interleaved; + buffer->step_rate = 0; for (i = 0; i < nr_uploads; i++) { /* Then, just point upload[i] at upload[0]'s buffer. */ -- 2.5.0.400.gff86faf _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/mesa-dev