<meta charset="UTF-8" />
<script src="http://spelprogrammering.nu/simple.js">
function start()
{
  scale(2.1,2.1);
  translate(-totalWidth/4-40,-totalHeight/2+10);
  g      = 9.82;
  l      = 2.5;
  theta0 = pi/4;
  theta  = 0;

  omega  = sqrt(g/l);
  t = 0;

  for(var i = 0; i<54; i++)
    fakeUpdate();

  math.polarLine(0,0,pi/4+3*pi/2, l, "black");
  math.polarPoint(pi/4+3*pi/2, l, 10, "blue");

  for (v = 3*pi/2;v < pi/4+3*pi/2;v+=0.005)
    math.polarPoint(v, 0.5, 0.5, "red");

  for (l = 0;l < 2.5;l+=0.2)
  {
    math.polarLine(3*pi/2, l, 3*pi/2, l+0.1, "black");
    math.polarLine(3*pi/2-pi/4, l, 3*pi/2-pi/4, l+0.1, "black");
  }

  math.text(0.8, -0.8, 30, "L", "black");
  math.text(2, -2, 30, "M", "blue");
  math.text(0.15, -0.75, 30, "θ", "red");
}

function fakeUpdate()
{
  theta = theta0*sin(omega*t+pi/2);
  math.polarPoint(theta+3*pi/2, l, 2, "green");
  t += 0.03;
}
</script>