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
36 extern "C" {
37 #endif
38
39 struct 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 */
47 static inline boolean
u_rect_test_intersection(const struct u_rect * a,const struct u_rect * b)48 u_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 */
63 static inline void
u_rect_find_intersection(const struct u_rect * a,struct u_rect * b)64 u_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
76 static inline int
u_rect_area(const struct u_rect * r)77 u_rect_area(const struct u_rect *r)
78 {
79 return (r->x1 - r->x0) * (r->y1 - r->y0);
80 }
81
82 static inline void
u_rect_possible_intersection(const struct u_rect * a,struct u_rect * b)83 u_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 */
101 static inline void
u_rect_union(struct u_rect * d,const struct u_rect * a,const struct u_rect * b)102 u_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