Dogcows Code - chaz/yoink/blob - src/rectangle.hh

   1
   2 /*******************************************************************************
   3
   4  Copyright (c) 2009, Charles McGarvey
   5  All rights reserved.
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   7  Redistribution   and   use  in  source  and  binary  forms,  with  or  without
   8  modification, are permitted provided that the following conditions are met:
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  10    * Redistributions  of  source  code  must retain the above copyright notice,
  11      this list of conditions and the following disclaimer.
  12    * Redistributions  in binary form must reproduce the above copyright notice,
  13      this  list of conditions and the following disclaimer in the documentation
  14      and/or other materials provided with the distribution.
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  16  THIS  SOFTWARE  IS  PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  17  AND  ANY  EXPRESS  OR  IMPLIED  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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  19  DISCLAIMED.  IN  NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
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  27 *******************************************************************************/
  28
  29 #ifndef _RECTANGLE_HH_
  30 #define _RECTANGLE_HH_
  31
  32 #include "math.hh"
  33 #include "vector.hh"
  34
  35
  36 namespace dc {
  37
  38 //
  39 // A rectangle is a 2d shape defined by point (origin) and size (width & height)
  40 // vectors.  The usual rectangle maths are available.  Valid rectangles have
  41 // positive width and height.  Invalid rectangles will be returned for invalid
  42 // operations such as trying to get the intersection of two rectangles which
  43 // don't intersect.  Using an invalid rectangle is undefined, but it may be used
  44 // after "fixing" it using the fix method which will cause the size to be
  45 // positive and adjust the origin to be the bottom-left point.  Check the
  46 // validity of a rectangle using the isValid method especially if the rectangle
  47 // is a result of an operation which could fail.
  48 //
  49
  50 class rectangle
  51 {
  52 public:
  53         // Constructors.
  54         rectangle() {}
  55         rectangle(point o, point s) {
  56                 origin = o;
  57                 size = s;
  58         }
  59
  60         // Rectangle validity.
  61         bool isValid() const { return size.x >= 0.0 && size.y >= 0.0; }
  62         void fix()
  63         {
  64                 if (size.x <= 0.0)
  65                 {
  66                         size.x = 0.0 - size.x;
  67                         origin.x -= size.x;
  68                 }
  69                 if (size.y <= 0.0)
  70                 {
  71                         size.y = 0.0 - size.y;
  72                         origin.y -= size.y;
  73                 }
  74         }
  75
  76         // Rectangle operations.
  77         scalar area() const { return size.x * size.y; }
  78         scalar perimeter() const {
  79                 return  size.x + size.x + size.y + size.y;
  80         }
  81
  82         bool containsPoint(point pt) const
  83         {
  84                 return origin.x <= pt.x && origin.y <= pt.y &&
  85                            pt.x <= origin.x + size.x && pt.y <= origin.y + size.y;
  86         }
  87
  88         void inset(scalar h, scalar v)
  89         {
  90                 origin.x        += h;
  91                 origin.y        += v;
  92                 size.x          -= h + h;
  93                 size.y          -= v + v;
  94         }
  95         void offset(scalar h, scalar v)
  96         {
  97                 origin.x        -= h;
  98                 origin.y        -= v;
  99                 size.x          += h + h;
 100                 size.y          += v + v;
 101         }
 102
 103         bool containsRect(const rectangle& r) const;
 104         bool intersectsRect(const rectangle& r) const;
 105         rectangle unionWith(const rectangle& r) const;
 106         rectangle intersectionWith(const rectangle& r) const;
 107
 108         // Checking equality.
 109         bool operator == (const rectangle& r) const {
 110                 return origin == r.origin && size == r.size;
 111         }
 112         bool operator != (const rectangle& r) const {
 113                 return !(*this == r);
 114         }
 115
 116         // Data.
 117         point origin, size;
 118 };
 119
 120 } // namespace dc
 121
 122
 123 #endif // _RECTANGLE_HH_
 124