From fec4f5de67b22a7048266fb7e57f49fe6fc3744a Mon Sep 17 00:00:00 2001 From: Roland Scheidegger Date: Tue, 1 Sep 2015 16:29:17 -0600 Subject: [PATCH] gallium/util: return FALSE for intersection if there's empty rectangles It isn't really obvious if intersection test should take into account empty rectangles or if the caller should do it. But it looks like most callers actually verified one of the rects but not the other, but since correctly returning an empty rect that other rect could actually be empty leading to more bugs. Hence just verify both rects for emptyness in the intersection test itself which makes the code easier in the caller (though it will be slower if the caller knows the rectangles are non-empty). Reviewed-by: Zack Rusin --- src/gallium/auxiliary/util/u_rect.h | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/src/gallium/auxiliary/util/u_rect.h b/src/gallium/auxiliary/util/u_rect.h index b26f671f313..dea1e1ecff3 100644 --- a/src/gallium/auxiliary/util/u_rect.h +++ b/src/gallium/auxiliary/util/u_rect.h @@ -42,6 +42,7 @@ struct u_rect { }; /* Do two rectangles intersect? + * Note: empty rectangles are valid as inputs (and never intersect). */ static inline boolean u_rect_test_intersection(const struct u_rect *a, @@ -50,7 +51,11 @@ u_rect_test_intersection(const struct u_rect *a, return (!(a->x1 < b->x0 || b->x1 < a->x0 || a->y1 < b->y0 || - b->y1 < a->y0)); + b->y1 < a->y0 || + a->x1 < a->x0 || + a->y1 < a->y0 || + b->x1 < b->x0 || + b->y1 < b->y0)); } /* Find the intersection of two rectangles known to intersect. -- 2.30.2