Square hittest

/**
 * Copyright Thumasz ( http://wonderfl.net/user/Thumasz )
 * MIT License ( http://www.opensource.org/licenses/mit-license.php )
 * Downloaded from: http://wonderfl.net/c/i90L
 */

package {
////////////////////////////////////////////////////
import flash.display.*;
import flash.events.*;
import flash.text.*;
import flash.geom.*;

public class FlashTest extends Sprite
{
    private var sq0:Square;
    private var sq1:Square;
    public function FlashTest() 
    {
        sq0 = new Square(0x666666, 150);
        addChild(sq0);
        sq0.x=sq0.y=150;
        //
        sq1 = new Square(0x000000, 50);
        addChild(sq1);
        sq1.x=sq1.y=50;
        sq1.buttonMode=true;
        //
        sq0.addEventListener(MouseEvent.MOUSE_DOWN, mDown);
        sq0.addEventListener(MouseEvent.MOUSE_UP, mUp);
        sq1.addEventListener(MouseEvent.MOUSE_DOWN, mDown);
        sq1.addEventListener(MouseEvent.MOUSE_UP, mUp);
        
        addEventListener(Event.ENTER_FRAME, update);
    }
    
    public function update(e:Event):void{
        switch(checkCollision(sq0, sq1)){
            case 0:
                sq0.setColor(0xCCCCCC);
            break;
            case 1:
                sq0.setColor(0x000000);
            break;
            case 2:
                sq0.setColor(0xFF0000);
            break;
            case 3:
                sq0.setColor(0x00FF00);
            break;
            case 4:
                sq0.setColor(0x0000FF);
            break;
            case 5:
                sq0.setColor(0xFF00FF);
            break;
        }

    }
    
    public function checkCollision(a:Square, b:Square):int{
        var aMin:Point = new Point(a.x, a.y);
        var aMax:Point = new Point(a.x + a.width, a.y + a.height);
        
        var bMin:Point = new Point(b.x, b.y);
        var bMax:Point = new Point(b.x + b.width, b.y + b.height);
        
         var left:Number = bMin.x - aMax.x;
         var right:Number = bMax.x - aMin.x;
         var top:Number = bMin.y - aMax.y;
         var bottom:Number = bMax.y - aMin.y;

         if(left > 0) return 0;
         if(right < 0) return 0;
         if(top > 0) return 0;
         if(bottom < 0) return 0;
        
        var returnCode:Point = new Point();
        
        returnCode.x = (Math.abs(left) - right) * a.width;
        returnCode.y = (Math.abs(top) - bottom) * a.height;
        
        var temp:int = 0;
        
        if(returnCode.x > 0){
            //Hits left
            temp = 2;
        }else{
            //Hits right
            temp = 3;
        }
        
        if(returnCode.y > 0){
            //Hits top
            if(returnCode.y > Math.abs(returnCode.x)){
                temp = 4;
            }
        }else{
            //Hits bottom
            if(returnCode.y < -Math.abs(returnCode.x)){
                temp = 5;
            }
        }


        
        return temp;
    }
    
    public function mDown(e:MouseEvent):void{
        e.target.startDrag();
    }

    public function mUp(e:MouseEvent):void{
        e.target.stopDrag();
    }

}
////////////////////////////////////////////////////
}


import flash.display.*;
internal class Square extends Sprite{
    
    private var _size:int;
   public function Square(color:uint,size:int){
      graphics.beginFill(color);
      graphics.drawRect(0, 0, size, size);
      _size = size;
   }
   
   public function setColor(color:uint):void{
      graphics.clear();
      graphics.beginFill(color);
      graphics.drawRect(0, 0, _size, _size);
   }

}