egret 示例实战四：圆弧遮罩

1.绘制圆弧

1 private initGraphics(){
2         this.shape = new egret.Shape();
3         this.shape.x = Main.instance.stage.stageWidth/2;
4         this.shape.y = Main.instance.stage.stageHeight/2;
5         this.addChild(this.shape);
6 }

2.计时修改弧度

 1 private changeGraphics(){
 2         let shape = this.shape;
 3         let angle = 0;
 4         let i = 1;
 5         egret.startTick(function(timeStamp:number):boolean{
 6             changeGraphics(angle);
 7             angle += 1;
 8             if(angle >= 360){
 9                 angle = angle/360;
10                 i *= -1;
11             }
12             return false;
13         },this);
14         function changeGraphics(angle){
15             shape.graphics.clear();
16             shape.graphics.beginFill(0xB0E2FF,1);
17             shape.graphics.moveTo(0,0);
18             shape.graphics.lineTo(200,0);
19             shape.graphics.drawArc(0,0,200,0,angle*Math.PI/180,i == -1);
20             shape.graphics.lineTo(0,0);
21             shape.graphics.endFill();
22         }
23     }

3.效果

4.添加一个爱心图片对象

1         let img = CommonFun.creatBitmapByName('love_png');
2         img.x = Main.instance.stage.stageWidth/2;
3         img.y = Main.instance.stage.stageHeight/2;
4         img.anchorOffsetX = img.width/2;
5         img.anchorOffsetY = img.height/2;
6         this.addChild(img);

5.效果

6.设置圆弧为爱心图片的遮罩

1 img.mask = this.shape;

7.效果