1/**************************************************************************
2 *
3 * Copyright 2008 VMware, Inc.
4 * All Rights Reserved.
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a
7 * copy of this software and associated documentation files (the
8 * "Software"), to deal in the Software without restriction, including
9 * without limitation the rights to use, copy, modify, merge, publish,
10 * distribute, sub license, and/or sell copies of the Software, and to
11 * permit persons to whom the Software is furnished to do so, subject to
12 * the following conditions:
13 *
14 * The above copyright notice and this permission notice (including the
15 * next paragraph) shall be included in all copies or substantial portions
16 * of the Software.
17 *
18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
19 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
20 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
21 * IN NO EVENT SHALL VMWARE AND/OR ITS SUPPLIERS BE LIABLE FOR
22 * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
23 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
24 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
25 *
26 **************************************************************************/
27
28
29#ifndef U_RECT_H
30#define U_RECT_H
31
32#include "pipe/p_compiler.h"
33#include "util/u_math.h"
34
35#ifdef __cplusplus
36extern "C" {
37#endif
38
39struct u_rect {
40   int x0, x1;
41   int y0, y1;
42};
43
44/* Do two rectangles intersect?
45 * Note: empty rectangles are valid as inputs (and never intersect).
46 */
47static inline boolean
48u_rect_test_intersection(const struct u_rect *a,
49                         const struct u_rect *b)
50{
51   return (!(a->x1 < b->x0 ||
52             b->x1 < a->x0 ||
53             a->y1 < b->y0 ||
54             b->y1 < a->y0 ||
55             a->x1 < a->x0 ||
56             a->y1 < a->y0 ||
57             b->x1 < b->x0 ||
58             b->y1 < b->y0));
59}
60
61/* Find the intersection of two rectangles known to intersect.
62 */
63static inline void
64u_rect_find_intersection(const struct u_rect *a,
65                         struct u_rect *b)
66{
67   /* Caller should verify intersection exists before calling.
68    */
69   if (b->x0 < a->x0) b->x0 = a->x0;
70   if (b->x1 > a->x1) b->x1 = a->x1;
71   if (b->y0 < a->y0) b->y0 = a->y0;
72   if (b->y1 > a->y1) b->y1 = a->y1;
73}
74
75
76static inline int
77u_rect_area(const struct u_rect *r)
78{
79   return (r->x1 - r->x0) * (r->y1 - r->y0);
80}
81
82static inline void
83u_rect_possible_intersection(const struct u_rect *a,
84                             struct u_rect *b)
85{
86   if (u_rect_test_intersection(a,b)) {
87      u_rect_find_intersection(a,b);
88   }
89   else {
90      /*
91       * Note the u_rect_xx tests deal with inclusive coordinates
92       * hence all-zero would not be an empty box.
93       */
94      b->x0 = b->y0 = 0;
95      b->x1 = b->y1 = -1;
96   }
97}
98
99/* Set @d to a rectangle that covers both @a and @b.
100 */
101static inline void
102u_rect_union(struct u_rect *d, const struct u_rect *a, const struct u_rect *b)
103{
104   d->x0 = MIN2(a->x0, b->x0);
105   d->y0 = MIN2(a->y0, b->y0);
106   d->x1 = MAX2(a->x1, b->x1);
107   d->y1 = MAX2(a->y1, b->y1);
108}
109
110#ifdef __cplusplus
111}
112#endif
113
114#endif /* U_RECT_H */
115