-#define RECT_CONTAINS(r, x, y) \
- (x >= (r).x && x < (r).x + (r).width && \
- y >= (r).y && y < (r).y + (r).height)
+#define RECT_CONTAINS(r, px, py) \
+ ((px) >= (r).x && (px) < (r).x + (r).width && \
+ (py) >= (r).y && (py) < (r).y + (r).height)
+#define RECT_CONTAINS_RECT(r, o) \
+ ((o).x >= (r).x && (o).x + (o).width <= (r).x + (r).width && \
+ (o).y >= (r).y && (o).y + (o).height <= (r).y + (r).height)
+#define RECT_INTERSECTS_RECT(r, o) \
+ ((o).x < (r).x + (r).width && (o).x + (o).width > (r).x && \
+ (o).y < (r).y + (r).height && (o).y + (o).height > (r).y)
+
+#define RECT_SET_INTERSECTION(r, a, b) \
+ ((r).x = MAX((a).x, (b).x), \
+ (r).y = MAX((a).y, (b).y), \
+ (r).width = MIN((a).x + (a).width - 1, \
+ (b).x + (b).width - 1) - (r).x + 1, \
+ (r).height = MIN((a).y + (a).height - 1, \
+ (b).y + (b).height - 1) - (r).y + 1)