HTML5 Game - Canvas Animation Pulsing motion

Introduction

The following code uses sine values to scale the ball.
Demo

<!doctype html>  
    <html>  
     <body>  
      <canvas id="canvas" width="400" height="400"></canvas>  
      <script>  
class Ball{  /*from  ww  w. j  a  v  a 2 s . c o  m*/
  constructor(radius, color) {
      if (radius === undefined) { radius = 40; }  
      if (color === undefined) { color = "#ff0000"; }  
      this.x = 0;  
      this.y = 0;  
      this.radius = radius;  
      this.rotation = 0;  
      this.scaleX = 1;  
      this.scaleY = 1;  
      this.color = color;  
      this.lineWidth = 1;  
    }  
      
    draw = function (context) {  
      context.save();  
      context.translate(this.x, this.y);  
      context.rotate(this.rotation);  
      context.scale(this.scaleX, this.scaleY);  
      context.lineWidth = this.lineWidth;  
      context.fillStyle = this.color;  
      context.beginPath();  
      //x, y, radius, start_angle, end_angle, anti-clockwise  
      context.arc(0, 0, this.radius, 0, (Math.PI * 2), true);  
      context.closePath();  
      context.fill();  
      if (this.lineWidth > 0) {  
        context.stroke();  
      }  
      context.restore();  
    }
} 
      window.onload = function () {  
        let canvas = document.getElementById('canvas'),  
            context = canvas.getContext('2d'),  
            ball = new Ball(),  
            angle = 0,  
            centerScale = 1,  
            range = 0.5,  
            speed = 0.05;  
      
        ball.x = canvas.width / 2;  
        ball.y = canvas.height / 2;  
      
        (function drawFrame () {  
          window.requestAnimationFrame(drawFrame, canvas);  
          context.clearRect(0, 0, canvas.width, canvas.height);  
      
          ball.scaleX = ball.scaleY = centerScale + Math.sin(angle) * range;  
          angle += speed;  
          ball.draw(context);  
        }());  
      };  
      </script>  
     </body>  
    </html>