Permalink
Switch branches/tags
Nothing to show
Find file Copy path
Fetching contributors…
Cannot retrieve contributors at this time
92 lines (83 sloc) 2.69 KB
<!doctype html>
<html>
<head>
<meta charset="utf-8">
<title>Bubbles 3</title>
<link rel="stylesheet" href="../include/style.css">
</head>
<body>
<header>
Example from <a href="http://amzn.com/1430236655?tag=html5anim-20"><em>Foundation HTML5 Animation with JavaScript</em></a>
</header>
<canvas id="canvas" width="400" height="400"></canvas>
<script src="../include/utils.js"></script>
<script src="./classes/ball.js"></script>
<script>
window.onload = function () {
var canvas = document.getElementById('canvas'),
context = canvas.getContext('2d'),
balls = [],
numBalls = 10,
bounce = -0.5,
spring = 0.015,
gravity = 0.1;
for (var ball, i = 0; i < numBalls; i++) {
ball = new Ball(Math.random() * 30 + 20, Math.random() * 0xffffff);
ball.x = Math.random() * canvas.width / 2;
ball.y = Math.random() * canvas.height / 2;
ball.vx = Math.random() * 6 - 3;
ball.vy = Math.random() * 6 - 3;
balls.push(ball);
}
function checkCollision (ballA, i) {
for (var ballB, dx, dy, dist, min_dist, j = i + 1; j < numBalls; j++) {
ballB = balls[j];
dx = ballB.x - ballA.x;
dy = ballB.y - ballA.y;
dist = Math.sqrt(dx * dx + dy * dy);
min_dist = ballA.radius + ballB.radius;
if (dist < min_dist) {
var tx = ballA.x + dx / dist * min_dist,
ty = ballA.y + dy / dist * min_dist,
ax = (tx - ballB.x) * spring,
ay = (ty - ballB.y) * spring;
ballA.vx -= ax;
ballA.vy -= ay;
ballB.vx += ax;
ballB.vy += ay;
}
}
}
function move (ball) {
ball.vy += gravity;
ball.x += ball.vx;
ball.y += ball.vy;
if (ball.x + ball.radius > canvas.width) {
ball.x = canvas.width - ball.radius;
ball.vx *= bounce;
} else if (ball.x - ball.radius < 0) {
ball.x = ball.radius;
ball.vx *= bounce;
}
if (ball.y + ball.radius > canvas.height) {
ball.y = canvas.height - ball.radius;
ball.vy *= bounce;
} else if (ball.y - ball.radius < 0) {
ball.y = ball.radius;
ball.vy *= bounce;
}
}
function draw (ball) {
ball.draw(context);
}
(function drawFrame () {
window.requestAnimationFrame(drawFrame, canvas);
context.clearRect(0, 0, canvas.width, canvas.height);
balls.forEach(checkCollision);
balls.forEach(move);
balls.forEach(draw);
}());
};
</script>
</body>
</html>