Gradient Matrixの練習

↓夏blogエントリーから勉強させていただきました。
http://nutsu.com/blog/2009/020921_as_gradient_matrix.html

by sakusan393 28 Oct 2009

• Related works: 1
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/*
↓夏blogエントリーから勉強させていただきました。
http://nutsu.com/blog/2009/020921_as_gradient_matrix.html




*/


package  {
	import flash.display.MovieClip;
	import flash.display.Sprite;
	import flash.events.Event;
	import flash.geom.Matrix;
	import flash.geom.Point;
	import flash.display.GradientType;
	
	
	public class Main extends MovieClip{
		var x0:int = 100;
		var x1:int=  275;
		var y0:int= 100;
		var y1:int = 100;
		var speedX:int = 25;
		var speedY:int = 10;
		var pt0:Sprite = new Sprite();
		var pt1:Sprite = new Sprite();
		
                //グラデーションの設定
		var colors:Array = [0xff66ff,0x55aacc];
		var alphas:Array = [100,100];
		var ratios:Array = [0,0xff];
		
		public function Main() {
			pt0.x = x0;
			pt0.y = y0;
			pt0.graphics.beginFill(0xFF0000);
			pt0.graphics.drawCircle(0,0,10);
			pt0.graphics.endFill();
			addChild(pt0);

			pt1.x = x1;
			pt1.y = y1;
			pt1.graphics.beginFill(0x0000FF);
			pt1.graphics.drawCircle(0,0,10);
			pt1.graphics.endFill();
			addChild(pt1);
			
			addEventListener(Event.ENTER_FRAME,xStageEnterFrame);
		}
		function xStageEnterFrame(e:Event):void {
			if(pt0.x > stage.stageWidth){
				speedX = speedX*-1
			}
			if(pt0.x < 0){
				speedX = speedX*-1
			}
			if(pt1.y > stage.stageHeight){
				speedY = speedY*-1
			}
			if(pt1.y < 0){
				speedY = speedY*-1
			}
			
			
			pt0.x += speedX;
			pt1.y += speedY;
			
			var matrix:Matrix = new Matrix();
			//とりあえず単位行列的な
			matrix.createGradientBox( 1, 1, 0, -0.5, -0.5 );

			//線分のベクトル
			var vx:Number = pt1.x - pt0.x;
			var vy:Number = pt1.y - pt0.y;

			//線分の長さ(p0,p1の距離)
			var w:Number  = Math.sqrt( vx*vx + vy*vy );

			//傾き
			var r:Number  = Math.atan2( vy, vx );

			//中点
			var cx:Number = (pt0.x + pt1.x)/2;
			var cy:Number = (pt0.y + pt1.y)/2;

			//あとはあててくだけ
			matrix.scale( w, 1 );//線形なんで高さは 1 にしとく
			matrix.rotate( r );
			matrix.translate( cx, cy );



			graphics.beginGradientFill(GradientType.LINEAR, colors, alphas, ratios, matrix);
			graphics.drawRect(0, 0, stage.stageWidth, stage.stageHeight);
		}
	}
	
}