mirror of
https://github.com/scratchfoundation/paper.js.git
synced 2025-01-01 10:48:38 -05:00
140 lines
No EOL
3.5 KiB
HTML
140 lines
No EOL
3.5 KiB
HTML
<!DOCTYPE html>
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<html>
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<head>
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<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
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<title>Future Splash</title>
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<link rel="stylesheet" href="../css/style.css">
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<script type="text/javascript" src="../../dist/paper.js"></script>
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<script type="text/paperscript" canvas="canvas">
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// Code ported to Paper.js from http://the389.com/9/1/
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// with permission.
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var values = {
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friction: 0.8,
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timeStep: 0.01,
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amount: 15,
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mass: 2,
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count: 0
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};
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values.invMass = 1 / values.mass;
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var path;
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var size = view.size * [1.2, 1];
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var Spring = Base.extend({
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initialize: function(a, b, param) {
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if (!param)
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param = {};
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this.a = a;
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this.b = b;
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this.restLength = param.restLength || 80;
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this.strength = param.strength ? param.strength : 0.55;
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this.mamb = values.invMass * values.invMass;
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},
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update: function() {
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var delta = this.b - this.a;
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var dist = delta.length;
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var normDistStrength = (dist - this.restLength) /
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(dist * (this.mamb)) * this.strength;
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delta.y *= (normDistStrength * values.invMass) / 5;
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if (!this.a.fixed)
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this.a.y += delta.y;
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if (!this.b.fixed)
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this.b.y -= delta.y;
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}
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});
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function createPath(strength) {
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var path = new Path();
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path.data = {};
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path.data.springs = [];
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path.fillColor = 'black';
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segments = path.segments;
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var previous;
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for (var i = 0; i <= values.amount; i++) {
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var segment = path.add(new Point(i / values.amount, 0.5) * size);
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var point = segment.point;
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point.px = point.x;
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point.py = point.y;
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point.fixed = i === 0 || i == values.amount;
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if (previous) {
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var spring = new Spring(previous, point, {
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strength: strength
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});
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path.data.springs.push(spring);
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}
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previous = point;
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}
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path.position.x -= size.width / 4;
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return path;
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}
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function onResize() {
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values.count = 0;
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if (path) {
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path.remove();
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}
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size = view.bounds.size * [2, 1];
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path = createPath(0.1);
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}
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function onMouseMove(event) {
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var segments = path.segments;
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var index = Math.floor((event.point.x + size.width / 4) * segments.length / size.width);
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var y = event.point.y;
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var range = size.height / 4;
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var segment = segments[index];
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var point = segment.point;
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var prev, next;
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if (segment.previous)
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prev = segment.previous.point;
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if (segment.next)
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next = segment.next.point;
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if (!point.fixed && y + range > point.y && y - range < point.y) {
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point.y += (y - point.y) / 6;
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if (prev && !prev.fixed) prev.y += (y - prev.y) / 12;
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if (next && !next.fixed) next.y += (y - next.y) / 12;
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}
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}
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function onFrame(event) {
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if (values.count != 0) {
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path.firstSegment.remove();
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path.lastSegment.remove();
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}
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updateWave(path);
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values.count++;
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}
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function updateWave(path) {
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var segments = path.segments;
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var force = 1 - values.friction * values.timeStep * values.timeStep;
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for (var i = 0, l = segments.length; i < l; i++) {
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var point = segments[i].point;
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var ty = point.y;
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var dy = (point.y - point.py) * force;
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point.y += dy;
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point.py = ty;
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point.y = Math.max(0, point.y);
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}
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for (var j = 0, l = path.data.springs.length; j < l; j++) {
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path.data.springs[j].update(true);
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}
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path.smooth();
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path.insert(0, new Point(0, size.height));
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path.add(new Point(size));
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}
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function onKeyDown(event) {
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if (event.key == 'space')
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path.fullySelected = !path.fullySelected;
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}
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</script>
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</head>
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<body>
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<canvas id="canvas" resize></canvas>
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</body>
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</html> |