| 1 | <!DOCTYPE html>
|
|---|
| 2 | <html>
|
|---|
| 3 | <head>
|
|---|
| 4 | <meta charset="UTF-8">
|
|---|
| 5 | <title>Bouncing Balls</title>
|
|---|
| 6 | <link rel="stylesheet" href="../css/style.css">
|
|---|
| 7 | <script type="text/javascript" src="../../dist/paper.js"></script>
|
|---|
| 8 | <script type="text/paperscript" canvas="canvas">
|
|---|
| 9 | var Ball = function(point, vector) {
|
|---|
| 10 | if (!vector || vector.isZero()) {
|
|---|
| 11 | this.vector = Point.random() * 5;
|
|---|
| 12 | } else {
|
|---|
| 13 | this.vector = vector * 2;
|
|---|
| 14 | }
|
|---|
| 15 | this.point = point;
|
|---|
| 16 | this.dampen = 0.4;
|
|---|
| 17 | this.gravity = 3;
|
|---|
| 18 | this.bounce = -0.6;
|
|---|
| 19 |
|
|---|
| 20 | var color = {
|
|---|
| 21 | hue: Math.random() * 360,
|
|---|
| 22 | saturation: 1,
|
|---|
| 23 | brightness: 1
|
|---|
| 24 | };
|
|---|
| 25 | var gradient = new Gradient([color, 'black'], true);
|
|---|
| 26 |
|
|---|
| 27 | var radius = this.radius = 50 * Math.random() + 30;
|
|---|
| 28 | // Wrap CompoundPath in a Group, since CompoundPaths directly
|
|---|
| 29 | // applies the transformations to the content, just like Path.
|
|---|
| 30 | var ball = new CompoundPath({
|
|---|
| 31 | children: [
|
|---|
| 32 | new Path.Circle({
|
|---|
| 33 | radius: radius
|
|---|
| 34 | }),
|
|---|
| 35 | new Path.Circle({
|
|---|
| 36 | center: radius / 8,
|
|---|
| 37 | radius: radius / 3
|
|---|
| 38 | })
|
|---|
| 39 | ],
|
|---|
| 40 | fillColor: new Color(gradient, 0, radius, radius / 8),
|
|---|
| 41 | });
|
|---|
| 42 |
|
|---|
| 43 | this.item = new Group({
|
|---|
| 44 | children: [ball],
|
|---|
| 45 | transformContent: false,
|
|---|
| 46 | position: this.point
|
|---|
| 47 | });
|
|---|
| 48 | }
|
|---|
| 49 |
|
|---|
| 50 | Ball.prototype.iterate = function() {
|
|---|
| 51 | var size = view.size;
|
|---|
| 52 | this.vector.y += this.gravity;
|
|---|
| 53 | this.vector.x *= 0.99;
|
|---|
| 54 | var pre = this.point + this.vector;
|
|---|
| 55 | if (pre.x < this.radius || pre.x > size.width - this.radius)
|
|---|
| 56 | this.vector.x *= -this.dampen;
|
|---|
| 57 | if (pre.y < this.radius || pre.y > size.height - this.radius) {
|
|---|
| 58 | if (Math.abs(this.vector.x) < 3)
|
|---|
| 59 | this.vector = Point.random() * [150, 100] + [-75, 20];
|
|---|
| 60 | this.vector.y *= this.bounce;
|
|---|
| 61 | }
|
|---|
| 62 |
|
|---|
| 63 | var max = Point.max(this.radius, this.point + this.vector);
|
|---|
| 64 | this.item.position = this.point = Point.min(max, size - this.radius);
|
|---|
| 65 | this.item.rotate(this.vector.x);
|
|---|
| 66 | };
|
|---|
| 67 |
|
|---|
| 68 |
|
|---|
| 69 | var balls = [];
|
|---|
| 70 | for (var i = 0; i < 10; i++) {
|
|---|
| 71 | var position = Point.random() * view.size,
|
|---|
| 72 | vector = (Point.random() - [0.5, 0]) * [50, 100],
|
|---|
| 73 | ball = new Ball(position, vector);
|
|---|
| 74 | balls.push(ball);
|
|---|
| 75 | }
|
|---|
| 76 |
|
|---|
| 77 | var textItem = new PointText({
|
|---|
| 78 | point: [20, 30],
|
|---|
| 79 | fillColor: 'black',
|
|---|
| 80 | content: 'Click, drag and release to add balls.'
|
|---|
| 81 | });
|
|---|
| 82 |
|
|---|
| 83 | var lastDelta;
|
|---|
| 84 | function onMouseDrag(event) {
|
|---|
| 85 | lastDelta = event.delta;
|
|---|
| 86 | }
|
|---|
| 87 |
|
|---|
| 88 | function onMouseUp(event) {
|
|---|
| 89 | var ball = new Ball(event.point, lastDelta);
|
|---|
| 90 | balls.push(ball);
|
|---|
| 91 | lastDelta = null;
|
|---|
| 92 | }
|
|---|
| 93 |
|
|---|
| 94 | function onFrame() {
|
|---|
| 95 | for (var i = 0, l = balls.length; i < l; i++)
|
|---|
| 96 | balls[i].iterate();
|
|---|
| 97 | }
|
|---|
| 98 | </script>
|
|---|
| 99 | </head>
|
|---|
| 100 | <body>
|
|---|
| 101 | <canvas id="canvas" resize></canvas>
|
|---|
| 102 | </body>
|
|---|
| 103 | </html> |
|---|
