resize된 canvas위에 대한 mouse좌표 스케일링

let rect = this.canvas.getBoundingClientRect();

        let scaleX = this.canvas.width/rect.width;
        let scaleY = this.canvas.height/rect.height;

        //resize된 캔버스 마우스 pos 재정렬
        this.mousePos.x = (e.clientX - rect.left)*scaleX
        this.mousePos.y = (e.clientY - rect.top)*scaleY