1: <?php
  2: 
  3: namespace Quadtree\Geometry;
  4: 
  5: /**
  6:  * A Bounds represents a rectangle on a two-dimensional plane
  7:  */
  8: class Bounds implements \Quadtree\Insertable
  9: {
 10:     /** @var float */
 11:     private $width;
 12:     
 13:     /** @var float */
 14:     private $height;
 15: 
 16:     /** @var float */
 17:     private $left;
 18:     
 19:     /** @var float */
 20:     private $top;
 21:     
 22:     /**
 23:      * @param float $width
 24:      * @param float $height
 25:      * @param float $left
 26:      * @param float $top
 27:      */
 28:     public function __construct($width, $height, $left = 0, $top = 0)
 29:     {
 30:         if (
 31:             !is_numeric($width)
 32:             || !is_numeric($height)
 33:             || !is_numeric($left) 
 34:             || !is_numeric($top)
 35:         ) {
 36:             throw new \InvalidArgumentException('Input must be numeric');
 37:         }
 38:         $this->width = (float)$width;
 39:         $this->height = (float)$height;
 40:         $this->left = (float)$left;
 41:         $this->top = (float)$top;
 42:     }
 43:     
 44:     /**
 45:      * @return float
 46:      */
 47:     function getWidth()
 48:     {
 49:         return $this->width;
 50:     }
 51: 
 52:     /**
 53:      * @return float
 54:      */
 55:     function getHeight()
 56:     {
 57:         return $this->height;
 58:     }
 59: 
 60:     /**
 61:      * @return float
 62:      */
 63:     function getLeft()
 64:     {
 65:         return $this->left;
 66:     }
 67: 
 68:     /**
 69:      * @return float
 70:      */
 71:     function getTop()
 72:     {
 73:         return $this->top;
 74:     }
 75:     
 76:     /**
 77:      * Returns true if the given point is in this bounds
 78:      * @param \Quadtree\Geometry\Point $point
 79:      * @return boolean
 80:      */
 81:     public function containsPoint(Point $point)
 82:     {
 83:         $leftIn = $point->getLeft() >= $this->left && $point->getLeft() < ($this->left + $this->width);
 84:         $topIn = $point->getTop() >= $this->top && $point->getTop() < ($this->top + $this->height);
 85:         return $leftIn && $topIn;
 86:     }
 87:     
 88:     /**
 89:      * Computes the center of this bounds
 90:      * @return \Quadtree\Geometry\Point
 91:      */
 92:     public function getCenter()
 93:     {
 94:         $left = $this->left + ($this->width / 2);
 95:         $top = $this->top + ($this->height / 2);
 96:         return new Point($left, $top);
 97:     }
 98:     
 99:     /**
100:      * Returns true if this bounds shares any points with other bounds
101:      * @param \Quadtree\Geometry\Bounds $other
102:      * @return boolean
103:      */
104:     public function intersects(Bounds $other)
105:     {
106:         return $this->left <= $other->getLeft() + $other->getWidth()
107:                 && $other->getLeft() <= $this->left + $this->width
108:                 && $this->top <= $other->getTop() + $other->getHeight()
109:                 && $other->getTop() <= $this->top + $this->height;
110:     }
111:     
112:     /**
113:      * Returns the intersection of two bounds
114:      * @param \Quadtree\Geometry\Bounds $other
115:      * @return \Quadtree\Geometry\Bounds | NULL
116:      */
117:     public function intersection(Bounds $other)
118:     {
119:         $x0 = max($this->left, $other->getLeft());
120:         $x1 = min($this->left + $this->width, $other->getLeft() + $other->getWidth());
121:         if ($x0 <= $x1) {
122:             $y0 = max($this->top, $other->getTop());
123:             $y1 = min($this->top + $this->height, $other->getTop() + $other->getHeight());
124:             if ($y0 <= $y1) {
125:                 return new static($x1 - $x0, $y1 - $y0, $x0, $y0);
126:             }
127:         }
128:         return NULL;
129:     }
130: 
131: 
132:     /**
133:      * Get 2D envelope
134:      * @return \Quadtree\Geometry\Bounds
135:      */
136:     public function getBounds()
137:     {
138:         return $this;
139:     }
140:     
141:     /**
142:      * Calculate size of area
143:      * @return float
144:      */
145:     public function getArea()
146:     {
147:         return $this->width * $this->height;
148:     }
149:     
150:     /**
151:      * Comparison function
152:      * @param \Quadtree\Geometry\Bounds $other
153:      * @return boolean
154:      */
155:     public function equals(Bounds $other)
156:     {
157:         return $this->width === $other->getWidth()
158:                 && $this->height === $other->getHeight()
159:                 && $this->left === $other->getLeft()
160:                 && $this->top === $other->getTop();
161:     }
162: }