From e23e4f67bed51a8dfd182eae6c7e8e23a7d2cb0e Mon Sep 17 00:00:00 2001 From: Roland Scheidegger Date: Tue, 21 Jan 2014 17:47:08 +0100 Subject: [PATCH] draw: fix points with negative w coords for d3d style point clipping Even with depth clipping disabled, vertices which have negative w coords must be discarded. And since we don't have a proper guardband implementation yet (relying on driver to handle all values except infs/nans in rasterization for such points) we need to kill them off manually (as they can end up with coordinates inside viewport otherwise). v2: use 0.0f instead of 0 (spotted by Brian). Reviewed-by: Jose Fonseca Reviewed-by: Brian Paul --- src/gallium/auxiliary/draw/draw_pipe_clip.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/src/gallium/auxiliary/draw/draw_pipe_clip.c b/src/gallium/auxiliary/draw/draw_pipe_clip.c index 8bdb882218b..de354e9e9da 100644 --- a/src/gallium/auxiliary/draw/draw_pipe_clip.c +++ b/src/gallium/auxiliary/draw/draw_pipe_clip.c @@ -635,8 +635,13 @@ clip_point_guard_xy( struct draw_stage *stage, clipmask &= ~(1 << plane_idx); /* turn off this plane's bit */ /* TODO: this should really do proper guardband clipping, * currently just throw out infs/nans. + * Also note that vertices with negative w values MUST be tossed + * out (not sure if proper guardband clipping would do this + * automatically). These would usually be captured by depth clip + * too but this can be disabled. */ - if (util_is_inf_or_nan(header->v[0]->clip[0]) || + if (header->v[0]->clip[3] <= 0.0f || + util_is_inf_or_nan(header->v[0]->clip[0]) || util_is_inf_or_nan(header->v[0]->clip[1])) return; } @@ -645,7 +650,6 @@ clip_point_guard_xy( struct draw_stage *stage, } - static void clip_first_point( struct draw_stage *stage, struct prim_header *header ) -- 2.30.2