sheedy · August 29, 2015 14:07
diff --git a/gistfile1.txt b/gistfile1.txt
 <!DOCTYPE html>
 <html>
    <head>
        <meta charset="utf-8" />
        <title>Balls.</title>
        <style>
        canvas { background-color: black; }
        </style>
    </head>
    <body>
        <canvas width="600" height="600" id="stage"></canvas>
        <script>
        var stage = document.getElementById("stage");

        var stageW = stage.width,
            stageH = stage.height;

        var ctx = stage.getContext("2d");

        function drawBall(ball) {
            ctx.fillStyle = "#0080ff";

            ctx.beginPath();
            ctx.arc(ball.x, ball.y, ball.r, 0, Math.PI * 2);
            ctx.closePath();

            ctx.fill();
        }

        var balls = [];

        var ballRadius = 20;

        for (var i = 0; i < 10; i++) {
            balls.push({
                x: Math.random() * (stageW - ballRadius * 2) + ballRadius,
                y: Math.random() * (stageH - ballRadius * 2) + ballRadius,
                r: ballRadius,
                vx: (Math.random() - 0.5) * 10,
                vy: (Math.random() - 0.5) * 10
            });
        }

        function draw() {
            ctx.globalAlpha = 0.2;
            ctx.drawImage(
                ctx.canvas,
                5,
                5,
                ctx.canvas.width - 10,
                ctx.canvas.height - 10,
                0, 0, ctx.canvas.width, ctx.canvas.height);

            ctx.globalAlpha = 0.02;
            ctx.fillStyle = "#401000";
            ctx.fillRect(0, 0, stageW, stageH);

            ctx.globalAlpha = 1;

            balls.forEach(drawBall);
        }

        var accX = 0;
            accY = 0.5;

        function process() {
            balls.forEach(function (ball) {
                ball.x += ball.vx;
                ball.y += ball.vy;

                if (ball.x < ballRadius) {
                    ball.x = ballRadius;
                    ball.vx = -ball.vx;
                } else if (ball.x > stageW - ballRadius) {
                    ball.x = stageW - ballRadius;
                    ball.vx = -ball.vx;
                }

                if (ball.y < ballRadius) {
                    ball.y = ballRadius;
                    ball.vy = -ball.vy;
                } else if (ball.y > stageH - ballRadius) {
                    ball.y = stageH - ballRadius;
                    ball.vy = -ball.vy;
                }

                ball.vy += accY;
                ball.vx += accX;
            });
        }

        function tick() {
            draw();
            process();

            window.setTimeout(tick, 1000 / 25);
        }

        tick();
        </script>
    </body>
 </html>
	<!DOCTYPE html>
	<html>
	<head>
	<meta charset="utf-8" />
	<title>Balls.</title>
	<style>
	canvas { background-color: black; }
	</style>
	</head>
	<body>
	<canvas width="600" height="600" id="stage"></canvas>
	<script>
	var stage = document.getElementById("stage");

	var stageW = stage.width,
	stageH = stage.height;

	var ctx = stage.getContext("2d");

	function drawBall(ball) {
	ctx.fillStyle = "#0080ff";

	ctx.beginPath();
	ctx.arc(ball.x, ball.y, ball.r, 0, Math.PI * 2);
	ctx.closePath();

	ctx.fill();
	}

	var balls = [];

	var ballRadius = 20;

	for (var i = 0; i < 10; i++) {
	balls.push({
	x: Math.random() * (stageW - ballRadius * 2) + ballRadius,
	y: Math.random() * (stageH - ballRadius * 2) + ballRadius,
	r: ballRadius,
	vx: (Math.random() - 0.5) * 10,
	vy: (Math.random() - 0.5) * 10
	});
	}

	function draw() {
	ctx.globalAlpha = 0.2;
	ctx.drawImage(
	ctx.canvas,
	5,
	5,
	ctx.canvas.width - 10,
	ctx.canvas.height - 10,
	0, 0, ctx.canvas.width, ctx.canvas.height);

	ctx.globalAlpha = 0.02;
	ctx.fillStyle = "#401000";
	ctx.fillRect(0, 0, stageW, stageH);

	ctx.globalAlpha = 1;

	balls.forEach(drawBall);
	}

	var accX = 0;
	accY = 0.5;

	function process() {
	balls.forEach(function (ball) {
	ball.x += ball.vx;
	ball.y += ball.vy;

	if (ball.x < ballRadius) {
	ball.x = ballRadius;
	ball.vx = -ball.vx;
	} else if (ball.x > stageW - ballRadius) {
	ball.x = stageW - ballRadius;
	ball.vx = -ball.vx;
	}

	if (ball.y < ballRadius) {
	ball.y = ballRadius;
	ball.vy = -ball.vy;
	} else if (ball.y > stageH - ballRadius) {
	ball.y = stageH - ballRadius;
	ball.vy = -ball.vy;
	}

	ball.vy += accY;
	ball.vx += accX;
	});
	}

	function tick() {
	draw();
	process();

	window.setTimeout(tick, 1000 / 25);
	}

	tick();
	</script>
	</body>
	</html>