getting started with animation

canvasAnimation

// jsfiddle.net

// functions
function drawBlueRectangle() {
  ctx.fillStyle = "blue";
  ctx.fillRect(0, 0, 50, 50);
}

// another function
function drawBlueCircle() {
  ctx.strokeStyle = "blue";
  ctx.beginPath();
  ctx.arc(95, 50, 40, 0, 2*Math.PI);
  ctx.stroke();
}

// functions with parameters
// functions
function drawRedRectangle(x, y) {
  ctx.fillStyle = "red";
  ctx.fillRect(x, y, 50, 50);
}

// problems

// make the shape go down

// make the shape go the left

// how do we prevent the shape from going past the boundary?