let bgImage = Sprite.from("bg.png");
let pMask = new Sprite;
bgImage.cacheAs = "bitmap";
bgImage.addChild(pMask);
let angle = 45;
pMask.graphics.clear();
let radius = 80;
pMask.graphics.drawPie([size=14]45[/size], [size=14]45[/size], [size=14]radius[/size], angle, 90, "#000000");
pMask.blendMode = "destination-out";
