src/gallium/auxiliary/util/u_rect.h

   1 /**************************************************************************
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   3  * Copyright 2008 VMware, Inc.
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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
  34 #ifdef __cplusplus
  35 extern "C" {
  36 #endif
  37
  38 struct u_rect {
  39    int x0, x1;
  40    int y0, y1;
  41 };
  42
  43 /* Do two rectangles intersect?
  44  */
  45 static INLINE boolean
  46 u_rect_test_intersection(const struct u_rect *a,
  47                          const struct u_rect *b)
  48 {
  49    return (!(a->x1 < b->x0 ||
  50              b->x1 < a->x0 ||
  51              a->y1 < b->y0 ||
  52              b->y1 < a->y0));
  53 }
  54
  55 /* Find the intersection of two rectangles known to intersect.
  56  */
  57 static INLINE void
  58 u_rect_find_intersection(const struct u_rect *a,
  59                          struct u_rect *b)
  60 {
  61    /* Caller should verify intersection exists before calling.
  62     */
  63    if (b->x0 < a->x0) b->x0 = a->x0;
  64    if (b->x1 > a->x1) b->x1 = a->x1;
  65    if (b->y0 < a->y0) b->y0 = a->y0;
  66    if (b->y1 > a->y1) b->y1 = a->y1;
  67 }
  68
  69
  70 static INLINE void
  71 u_rect_possible_intersection(const struct u_rect *a,
  72                              struct u_rect *b)
  73 {
  74    if (u_rect_test_intersection(a,b)) {
  75       u_rect_find_intersection(a,b);
  76    }
  77    else {
  78       b->x0 = b->x1 = b->y0 = b->y1 = 0;
  79    }
  80 }
  81
  82 #ifdef __cplusplus
  83 }
  84 #endif
  85
  86 #endif /* U_RECT_H */