src/gallium/auxiliary/util/u_rect.h

   1 /**************************************************************************
   2  *
   3  * Copyright 2008 VMware, Inc.
   4  * All Rights Reserved.
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  15  * next paragraph) shall be included in all copies or substantial portions
  16  * of the Software.
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  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  */
  46 static inline boolean
  47 u_rect_test_intersection(const struct u_rect *a,
  48                          const struct u_rect *b)
  49 {
  50    return (!(a->x1 < b->x0 ||
  51              b->x1 < a->x0 ||
  52              a->y1 < b->y0 ||
  53              b->y1 < a->y0));
  54 }
  55
  56 /* Find the intersection of two rectangles known to intersect.
  57  */
  58 static inline void
  59 u_rect_find_intersection(const struct u_rect *a,
  60                          struct u_rect *b)
  61 {
  62    /* Caller should verify intersection exists before calling.
  63     */
  64    if (b->x0 < a->x0) b->x0 = a->x0;
  65    if (b->x1 > a->x1) b->x1 = a->x1;
  66    if (b->y0 < a->y0) b->y0 = a->y0;
  67    if (b->y1 > a->y1) b->y1 = a->y1;
  68 }
  69
  70
  71 static inline int
  72 u_rect_area(const struct u_rect *r)
  73 {
  74    return (r->x1 - r->x0) * (r->y1 - r->y0);
  75 }
  76
  77 static inline void
  78 u_rect_possible_intersection(const struct u_rect *a,
  79                              struct u_rect *b)
  80 {
  81    if (u_rect_test_intersection(a,b)) {
  82       u_rect_find_intersection(a,b);
  83    }
  84    else {
  85       b->x0 = b->x1 = b->y0 = b->y1 = 0;
  86    }
  87 }
  88
  89 /* Set @d to a rectangle that covers both @a and @b.
  90  */
  91 static inline void
  92 u_rect_union(struct u_rect *d, const struct u_rect *a, const struct u_rect *b)
  93 {
  94    d->x0 = MIN2(a->x0, b->x0);
  95    d->y0 = MIN2(a->y0, b->y0);
  96    d->x1 = MAX2(a->x1, b->x1);
  97    d->y1 = MAX2(a->y1, b->y1);
  98 }
  99
 100 #ifdef __cplusplus
 101 }
 102 #endif
 103
 104 #endif /* U_RECT_H */