<script src="http://spelprogrammering.nu/simple.js">

function start()
{
  paddles = {speed: 15, width: 20, height: 80, distanceToWall: 20};
  ball    = {x: totalWidth / 2 - 10, y: totalHeight / 2 - 10, 
             size: 20, xSpeed: 10, ySpeed: random(12) - 6};
  p1 = {x: paddles.distanceToWall, y: totalHeight / 2 - paddles.height / 2};
  p2 = {x: totalWidth - paddles.distanceToWall - paddles.width, y: p1.y};
}

function update()
{
  if (keyboard.up)   { p2.y -= paddles.speed; }
  if (keyboard.down) { p2.y += paddles.speed; }
  if (keyboard.w)    { p1.y -= paddles.speed; }
  if (keyboard.s)    { p1.y += paddles.speed; }

  ball.x += ball.xSpeed;
  ball.y += ball.ySpeed;

  if (ball.y < 0 || ball.y > totalHeight - ball.size) 
    ball.ySpeed = -ball.ySpeed; 

  if ((ball.x > p1.x && 
       ball.y > p1.y - ball.size && 
       ball.y < p1.y + paddles.height && 
       ball.x < p1.x + paddles.width) 
      || 
      (ball.x < p2.x && 
       ball.y > p2.y - ball.size && 
       ball.y < p2.y + paddles.height && 
       ball.x > p2.x - ball.size))
  {
    ball.xSpeed = -ball.xSpeed - ball.xSpeed / abs(ball.xSpeed);
    ball.ySpeed = ball.ySpeed + random(8) - 4;
  }

  if (ball.x < 0 - ball.size || ball.x >= totalWidth) { start(); }

  fill("black");
  rectangle(p1.x, p1.y, paddles.width, paddles.height, "white");
  rectangle(p2.x, p2.y, paddles.width, paddles.height, "white");
  rectangle(ball.x, ball.y, ball.size, ball.size, "white");
}


</script>