context.fillRect(0, 0, 200, 200);
context.translate(100, 100);
context.strokeStyle = "orange";
context.lineWidth = 2;
var R = 36;  var r = 8;  var d = 15;  var t = 0;
var lastx = R + d - r;   var lasty = 0;
var id = window.setInterval(function() {
    context.beginPath();
    context.moveTo(lastx, lasty);
    var x = ((R - r) * Math.cos(t)) +
        (d * Math.cos(((R - r) / r) * t));
    var y = ((R - r) * Math.sin(t)) -
        (d * Math.sin(((R - r) / r) * t));
    context.lineTo(x, y);
    context.stroke();
    t += 0.1;  lastx = x;  lasty = y;
    if ((2 * 2 * Math.PI) < (t - 0.1)) {
        window.clearInterval(id);
    }
}, 50);
var sl = new Image();
sl.onload = function() {
    for (i = 0; i < 8; i++) {
        context.save();
        context.rotate((i / 8) * (2 * Math.PI));
        context.globalAlpha = (8 - i) / 4;
        context.drawImage(sl, -25, -100, 50, 50);
        context.restore();
    }
};
sl.src = "Silverlight.png";

processing.js example

// All Examples Written by Casey Reas and Ben Fry
// unless otherwise stated.
int xspacing = 8;   // How far apart should each horizontal location be spaced
int w;              // Width of entire wave

float theta = 0.0;       // Start angle at 0
float amplitude = 75.0;  // Height of wave
float period = 500.0;    // How many pixels before the wave repeats
float dx;                 // Value for incrementing X, to be calculated as a function of period and xspacing
float[] yvalues;          // Using an array to store height values for the wave (not entirely necessary)

void setup() {
  size(200,200);
  frameRate(30);
  colorMode(RGB,255,255,255,100);
  smooth();
  w = width+16;
  dx = (TWO_PI / period) * xspacing;
  yvalues = new float[w/xspacing];
}

void draw() {
  background(0);
  calcWave();
  renderWave();

}

void calcWave() {
  // Increment theta (try different values for 'angular velocity' here
  theta += 0.02;

  // For every x value, calculate a y value with sine function
  float x = theta;
  for (int i = 0; i < yvalues.length; i++) {
    yvalues[i] = sin(x)*amplitude;
    x+=dx;
  }
}

void renderWave() {
  // A simple way to draw the wave with an ellipse at each location
  for (int x = 0; x < yvalues.length; x++) {
    noStroke();
    fill(255,50);
    ellipseMode(CENTER);
    ellipse(x*xspacing,width/2+yvalues[x],16,16);
  }
}

context.fillStyle = "rgb(0, 162, 232)";
context.fillRect(0, 0, 100, 100);
context.save();
context.fillStyle = "rgba(255, 127, 39, 0.8)";
context.fillRect(25, 25, 100, 100);
context.strokeStyle = "rgb(255, 174, 201)";
context.lineWidth = 15;
context.strokeRect(50, 50, 100, 100);
context.restore();
context.beginPath()
context.moveTo(75, 75);
context.lineTo(175, 75);
context.lineTo(75, 175);
context.fill();
var gradient = context
    .createLinearGradient(150, 100, 150, 200);
gradient.addColorStop(0/5, "red");
gradient.addColorStop(1/5, "orange");
gradient.addColorStop(2/5, "yellow");
gradient.addColorStop(3/5, "green");
gradient.addColorStop(4/5, "blue");
gradient.addColorStop(5/5, "purple");
context.fillStyle = gradient;
context.fillRect(100, 100, 100, 100);