정교한 다각형 HitTest Class

기존의 HitTestpoint와 HitTestobject는 사실 오브젝트 vs 오브젝트인 경우

HitTest판별이 회전, 변형하는 직사각형 오각형같은 도형들에 관해선

사실상 정교한 판별이 불가능했고 특히 회전하는 경우엔 그야말로 뿌카능!! 하다..

그래서 분명 정교한 HitTest 클래스를 만든 소스가 있을거라 생각하고 뒤지던중

광명을 발견했다!!....

그래서 그 소스를 적어놓겠다능
(나능 관대하다능...)

http://www.tink.ws/blog/as-30-hittest/

 

package ws.tink.display
{
 
	import flash.display.BitmapData;
	import flash.display.BlendMode;
	import flash.display.DisplayObject;
	import flash.display.Sprite;
 
	import flash.geom.ColorTransform;
	import flash.geom.Matrix;
	import flash.geom.Point;
	import flash.geom.Rectangle;
 
	public class HitTest
	{
 
		public static function complexHitTestObject( target1:DisplayObject, target2:DisplayObject,  accurracy:Number = 1 ):Boolean
		{
			return complexIntersectionRectangle( target1, target2, accurracy ).width != 0;
		}
 
		public static function intersectionRectangle( target1:DisplayObject, target2:DisplayObject ):Rectangle
		{
			// If either of the items don't have a reference to stage, then they are not in a display list
			// or if a simple hitTestObject is false, they cannot be intersecting.
			if( !target1.root || !target2.root || !target1.hitTestObject( target2 ) ) return new Rectangle();
 
			// Get the bounds of each DisplayObject.
			var bounds1:Rectangle = target1.getBounds( target1.root );
			var bounds2:Rectangle = target2.getBounds( target2.root );
 
			// Determine test area boundaries.
			var intersection:Rectangle = new Rectangle();
			intersection.x 		= Math.max( bounds1.x, bounds2.x );
			intersection.y		= Math.max( bounds1.y, bounds2.y );
			intersection.width 	= Math.min( ( bounds1.x + bounds1.width ) - intersection.x, ( bounds2.x + bounds2.width ) - intersection.x );
			intersection.height = Math.min( ( bounds1.y + bounds1.height ) - intersection.y, ( bounds2.y + bounds2.height ) - intersection.y );
 
			return intersection;
		}
 
		public static function complexIntersectionRectangle( target1:DisplayObject, target2:DisplayObject, accurracy:Number = 1 ):Rectangle
		{			
			if( accurracy < = 0 ) throw new Error( "ArgumentError: Error #5001: Invalid value for accurracy", 5001 );
 
			// If a simple hitTestObject is false, they cannot be intersecting.
			if( !target1.hitTestObject( target2 ) ) return new Rectangle();
 
			var hitRectangle:Rectangle = intersectionRectangle( target1, target2 );
			// If their boundaries are no interesecting, they cannot be intersecting.
			if( hitRectangle.width * accurracy < 1 || hitRectangle.height * accurracy < 1 ) return new Rectangle();
 
			var bitmapData:BitmapData = new BitmapData( hitRectangle.width * accurracy, hitRectangle.height * accurracy, false, 0x000000 );	
 
			// Draw the first target.
			bitmapData.draw( target1, HitTest.getDrawMatrix( target1, hitRectangle, accurracy ), new ColorTransform( 1, 1, 1, 1, 255, -255, -255, 255 ) );
			// Overlay the second target.
			bitmapData.draw( target2, HitTest.getDrawMatrix( target2, hitRectangle, accurracy ), new ColorTransform( 1, 1, 1, 1, 255, 255, 255, 255 ), BlendMode.DIFFERENCE );
 
			// Find the intersection.
			var intersection:Rectangle = bitmapData.getColorBoundsRect( 0xFFFFFFFF,0xFF00FFFF );
 
			bitmapData.dispose();
 
			// Alter width and positions to compensate for accurracy
			if( accurracy != 1 )
			{
				intersection.x /= accurracy;
				intersection.y /= accurracy;
				intersection.width /= accurracy;
				intersection.height /= accurracy;
			}
 
			intersection.x += hitRectangle.x;
			intersection.y += hitRectangle.y;
 
			return intersection;
		}
 
 
		protected static function getDrawMatrix( target:DisplayObject, hitRectangle:Rectangle, accurracy:Number ):Matrix
		{
			var localToGlobal:Point;;
			var matrix:Matrix;
 
			var rootConcatenatedMatrix:Matrix = target.root.transform.concatenatedMatrix;
 
			localToGlobal = target.localToGlobal( new Point( ) );
			matrix = target.transform.concatenatedMatrix;
			matrix.tx = localToGlobal.x - hitRectangle.x;
			matrix.ty = localToGlobal.y - hitRectangle.y;
 
			matrix.a = matrix.a / rootConcatenatedMatrix.a;
			matrix.d = matrix.d / rootConcatenatedMatrix.d;
			if( accurracy != 1 ) matrix.scale( accurracy, accurracy );
 
			return matrix;
		}
 
	}
 
}