Pong #1: Paddle
by Calumks
HTML
<canvas id="canvas" width="480" height="320"></canvas>
JavaScript
var canvas = document.getElementById("canvas");
var context = canvas.getContext("2d");
var x = 1;
var y = 1;
var velocityX = 2;
var velocityY = 2;
draw();
function draw() {
context.clearRect(0, 0, 480, 320);
context.fillStyle = "#000000";
context.fillRect(x, y, 100, 100);
x+=velocityX;
y+=velocityY;
if (y <= 0 || y + 100 >= 320) {velocityY*=-1;}
if (x <= 0 || x + 100 >= 480) {velocityX*=-1;}
requestAnimationFrame(draw);
}