ferguson coons curve

/**
 * Copyright arumajirou ( http://wonderfl.net/user/arumajirou )
 * MIT License ( http://www.opensource.org/licenses/mit-license.php )
 * Downloaded from: http://wonderfl.net/c/6Msj
 */

package {
    import flash.display.Sprite;
	import flash.display.Graphics;
	import flash.geom.*;
	import flash.text.*;

	public class FlashTest extends Sprite {
		public var p0 : Vector3D;
		public var p1 : Vector3D;
		public var v0 : Vector3D;
		public var v1 : Vector3D;

		static public var tex : TextField = new TextField();

		public function FlashTest() {
			// write as3 code here..
			tex.autoSize = TextFieldAutoSize.LEFT;
			addChild( tex );
			const g : Graphics = graphics;
			g.lineStyle( 1, 0xff0000 );
			
			p0 = new Vector3D( 0, stage.stageHeight / 2, 0, 1 );
			p1 = new Vector3D( stage.stageWidth, stage.stageHeight / 2, 0, 1 );
			v0 = new Vector3D( 0, -200, 0, 0 );
			v1 = new Vector3D( 0,  200, 0, 0 );
	
			g.moveTo( 0, stage.stageHeight / 2 );			
			for( var i : Number = 0 ; i < stage.stageWidth ; i++ )
			{
				var x : Number = fergusonCoons( i / stage.stageWidth, 0, stage.stageWidth, 0, 0 );
				var y : Number = fergusonCoons( i / stage.stageWidth, stage.stageHeight / 2, stage.stageHeight /2, -200, 200 );
				g.lineTo( x, y );
			}
		}

		public function fergusonCoons( delta : Number, p0 : Number, p1 : Number, v0 : Number, v1 : Number ) : Number
		{
			return ( Math.pow( delta, 3 ) * ( 2 * (p0-p1) + v0 + v1 ) + Math.pow( delta, 2 ) * ( 3 * ( p1 - p0 ) - v1 - v0 - v0 ) + delta * v0 + p0 );
		}
	}
}