Initial gh-pages commit
This commit is contained in:
Dennis Hotson
commit
a4ccfd40b8
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index.html
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index.html
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<!DOCTYPE html>
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<html>
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<head>
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<title>Springy - A force directed graph layout algorithm in JavaScript.</title>
|
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<link href='http://fonts.googleapis.com/css?family=IM+Fell+English+SC|IM+Fell+English:400,400italic' rel='stylesheet' type='text/css'>
|
||||
<script src="springy.js"></script>
|
||||
<style>
|
||||
body {
|
||||
background: #FFF;
|
||||
font-family: 'IM Fell English', serif;
|
||||
font-size: 18px;
|
||||
line-height: 1.4;
|
||||
text-align: center;
|
||||
}
|
||||
|
||||
h1 {
|
||||
font-weight: normal;
|
||||
font-size: 48px;
|
||||
font-family: 'IM Fell English SC', serif;
|
||||
}
|
||||
|
||||
.subtitle {
|
||||
font-size: 24px;
|
||||
font-style: italic;
|
||||
}
|
||||
|
||||
h2 {
|
||||
font-weight: normal;
|
||||
font-size: 32px;
|
||||
font-family: 'IM Fell English SC', serif;
|
||||
margin-top: 0;
|
||||
}
|
||||
|
||||
.section {
|
||||
width: 650px;
|
||||
margin: 0 auto;
|
||||
text-align: left;
|
||||
}
|
||||
|
||||
.divider {
|
||||
margin: 30px 0;
|
||||
text-align: center;
|
||||
}
|
||||
|
||||
.example {
|
||||
box-sizing: border-box;
|
||||
background: #EEEEEE;
|
||||
box-shadow: 0 0 50px 0 rgba(0,0,0,0.2) inset;
|
||||
}
|
||||
|
||||
pre {
|
||||
font-family: monospace;
|
||||
background: #EEEEEE;
|
||||
padding: 15px;
|
||||
}
|
||||
.Function { font-weight: bold; }
|
||||
.Normal { font-weight: bold; }
|
||||
.Identifier { font-weight: bold; }
|
||||
.Comment { color: #808080; }
|
||||
</style>
|
||||
</head>
|
||||
<body>
|
||||
<h1>Springy.js</h1>
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<p class="subtitle">A force directed graph layout algorithm for JavaScript.</p>
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|
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<div class="divider"><img src="branch.png" align="top" /></div>
|
||||
<div id="what" class="section">
|
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<h2>What is Springy?</h2>
|
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<p>Springy is a force directed graph layout algorithm.</p>
|
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<p>So what does this “force directed” stuff mean anyway? Excellent question!</p>
|
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<p>It basically means that it uses some real world physics to try and figure out how to show a network graph in a nice way.</p>
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<p>Here's an example:</p>
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<canvas id="adv" class="example" width="650" height="300"></canvas>
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<p>You can imagine it as a bunch of springs connected to each other.</p>
|
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</div>
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|
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<script>
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(function() {
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// make a new graph
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var graph = new Graph();
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|
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// make some nodes
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var node1 = graph.newNode({label: 'Norway Spruce'});
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var node2 = graph.newNode({label: 'Sicilian Fir'});
|
||||
var node3 = graph.newNode({label: 'Sumatran Pine'});
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var node4 = graph.newNode({label: 'Japanese Larch'});
|
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|
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// connect them with an edge
|
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graph.newEdge(node1, node2);
|
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graph.newEdge(node2, node3);
|
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graph.newEdge(node2, node4);
|
||||
graph.newEdge(node1, node4);
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|
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var layout = new Layout.ForceDirected(
|
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graph,
|
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200.0, // Spring stiffness
|
||||
400.0, // Node repulsion
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||||
0.5 // Damping
|
||||
);
|
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|
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var canvas = document.getElementById('adv');
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var ctx = canvas.getContext('2d');
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||||
|
||||
var renderer = new Renderer(10, layout,
|
||||
function clear() {
|
||||
ctx.clearRect(0, 0, 650, 300);
|
||||
},
|
||||
function drawEdge(edge, p1, p2) {
|
||||
ctx.save();
|
||||
ctx.translate(325, 150);
|
||||
|
||||
ctx.strokeStyle = 'rgba(0,0,0,0.1)';
|
||||
ctx.lineWidth = 3.0;
|
||||
|
||||
ctx.beginPath();
|
||||
ctx.moveTo(p1.x * 50, p1.y * 40);
|
||||
ctx.lineTo(p2.x * 50, p2.y * 40);
|
||||
ctx.stroke();
|
||||
|
||||
ctx.restore();
|
||||
},
|
||||
function drawNode(node, p) {
|
||||
ctx.save();
|
||||
ctx.translate(325, 150);
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||||
|
||||
ctx.font = "18px 'IM Fell English', serif";
|
||||
|
||||
var width = ctx.measureText(node.data.label).width;
|
||||
var x = p.x * 50;
|
||||
var y = p.y * 40;
|
||||
ctx.clearRect(x - width / 2.0 - 5, y - 12, width + 10, 24);
|
||||
ctx.fillStyle = '#000000';
|
||||
ctx.fillText(node.data.label, x - width / 2.0, y + 5);
|
||||
|
||||
ctx.restore();
|
||||
}
|
||||
);
|
||||
|
||||
renderer.start();
|
||||
})()
|
||||
</script>
|
||||
<div class="divider"><img src="pine.png" /></div>
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||||
|
||||
<div id="usage" class="section">
|
||||
<h2>Basic usage</h2>
|
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<p>springy.js by itself is quite plain and doesn't include any code to do rendering or drag and drop etc. It's just for calculating the layout.</p>
|
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<p>The drawing and interaction stuff is mostly up to you.</p>
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<p>However, I've written a little helper jQuery plugin called springyui.js to help get you started. It's got a semi-decent default renderer and some half assed drag and drop.</p>
|
||||
<p>Take a look at <a href="#">demo.html</a> and <a href="#">springyui.js</a> for an example of usage.</p>
|
||||
</div>
|
||||
|
||||
<div class="divider"><img src="nut.png" /></div>
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||||
|
||||
<div id="usage" class="section">
|
||||
<h2>Advanced usage</h2>
|
||||
<p>If you're keen to do your own custom drawing, you'll need to know a few things before you get started.</p>
|
||||
<p>This is the basic graph API, you can create nodes and edges etc.</p>
|
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<pre>
|
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<span class="Comment">// make a new graph</span>
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<span class="Identifier">var</span> graph = <span class="Normal">new</span> Graph();
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|
||||
<span class="Comment">// make some nodes</span>
|
||||
<span class="Identifier">var</span> node1 = graph.newNode(<span class="Function">{</span>label: <span class="String">'Norway Spruce'</span><span class="Function">}</span>);
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||||
<span class="Identifier">var</span> node2 = graph.newNode(<span class="Function">{</span>label: <span class="String">'Sicilian Fir'</span><span class="Function">}</span>);
|
||||
|
||||
<span class="Comment">// connect them with an edge</span>
|
||||
graph.newEdge(node1, node2);
|
||||
</pre>
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||||
|
||||
<p>So now to draw this graph, lets make a layout object:</p>
|
||||
<pre>
|
||||
<span class="Identifier">var</span> layout = <span class="Normal">new</span> Layout.ForceDirected(
|
||||
graph,
|
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<span class="Constant">400</span>.<span class="Constant">0</span>, <span class="Comment">// Spring stiffness</span>
|
||||
<span class="Constant">400</span>.<span class="Constant">0</span>, <span class="Comment">// Node repulsion</span>
|
||||
<span class="Constant">0</span>.<span class="Constant">5</span> <span class="Comment">// Damping</span>
|
||||
);
|
||||
</pre>
|
||||
<p>I've written a Renderer class, which will handle the rendering loop. You just need to provide some callbacks to do the actual drawing.</p>
|
||||
<pre>
|
||||
<span class="Identifier">var</span> renderer = <span class="Normal">new</span> Renderer(<span class="Constant">10</span>, layout,
|
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<span class="Function">function</span> clear() <span class="Function">{</span>
|
||||
<span class="Comment">// code to clear screen</span>
|
||||
<span class="Function">}</span>,
|
||||
<span class="Function">function</span> drawEdge(edge, p1, p2) <span class="Function">{</span>
|
||||
<span class="Comment">// draw an edge</span>
|
||||
<span class="Function">}</span>,
|
||||
<span class="Function">function</span> drawNode(node, p) <span class="Function">{</span>
|
||||
<span class="Comment">// draw a node</span>
|
||||
<span class="Function">}</span>
|
||||
);
|
||||
</pre>
|
||||
|
||||
<p>Now, just start the rendering loop:</p>
|
||||
|
||||
<pre>
|
||||
renderer.start();
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||||
</pre>
|
||||
|
||||
<div class="divider"><img src="cone.png" /></div>
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||||
|
||||
<div id="usage" class="section">
|
||||
<h2>Acknowledgements</h2>
|
||||
</div>
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||||
|
||||
<div class="divider"><img src="dome.png" /></div>
|
||||
</body>
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||||
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578
springy.js
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springy.js
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/**
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* Springy v1.0.1
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*
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||||
* Copyright (c) 2010 Dennis Hotson
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*
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||||
* Permission is hereby granted, free of charge, to any person
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||||
* obtaining a copy of this software and associated documentation
|
||||
* files (the "Software"), to deal in the Software without
|
||||
* restriction, including without limitation the rights to use,
|
||||
* copy, modify, merge, publish, distribute, sublicense, and/or sell
|
||||
* copies of the Software, and to permit persons to whom the
|
||||
* Software is furnished to do so, subject to the following
|
||||
* conditions:
|
||||
*
|
||||
* The above copyright notice and this permission notice shall be
|
||||
* included in all copies or substantial portions of the Software.
|
||||
*
|
||||
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
|
||||
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
|
||||
* OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
|
||||
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
|
||||
* HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
|
||||
* WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
|
||||
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
|
||||
* OTHER DEALINGS IN THE SOFTWARE.
|
||||
*/
|
||||
|
||||
//https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/Array/forEach
|
||||
if ( !Array.prototype.forEach ) {
|
||||
Array.prototype.forEach = function( callback, thisArg ) {
|
||||
var T, k;
|
||||
if ( this == null ) {
|
||||
throw new TypeError( " this is null or not defined" );
|
||||
}
|
||||
var O = Object(this);
|
||||
var len = O.length >>> 0; // Hack to convert O.length to a UInt32
|
||||
if ( {}.toString.call(callback) != "[object Function]" ) {
|
||||
throw new TypeError( callback + " is not a function" );
|
||||
}
|
||||
if ( thisArg ) {
|
||||
T = thisArg;
|
||||
}
|
||||
k = 0;
|
||||
while( k < len ) {
|
||||
var kValue;
|
||||
if ( k in O ) {
|
||||
kValue = O[ k ];
|
||||
callback.call( T, kValue, k, O );
|
||||
}
|
||||
k++;
|
||||
}
|
||||
};
|
||||
}
|
||||
|
||||
var Graph = function() {
|
||||
this.nodeSet = {};
|
||||
this.nodes = [];
|
||||
this.edges = [];
|
||||
this.adjacency = {};
|
||||
|
||||
this.nextNodeId = 0;
|
||||
this.nextEdgeId = 0;
|
||||
this.eventListeners = [];
|
||||
};
|
||||
|
||||
var Node = function(id, data) {
|
||||
this.id = id;
|
||||
this.data = typeof(data) !== 'undefined' ? data : {};
|
||||
};
|
||||
|
||||
var Edge = function(id, source, target, data) {
|
||||
this.id = id;
|
||||
this.source = source;
|
||||
this.target = target;
|
||||
this.data = typeof(data) !== 'undefined' ? data : {};
|
||||
};
|
||||
|
||||
Graph.prototype.addNode = function(node) {
|
||||
if (typeof(this.nodeSet[node.id]) === 'undefined') {
|
||||
this.nodes.push(node);
|
||||
}
|
||||
|
||||
this.nodeSet[node.id] = node;
|
||||
|
||||
this.notify();
|
||||
return node;
|
||||
};
|
||||
|
||||
Graph.prototype.addEdge = function(edge) {
|
||||
var exists = false;
|
||||
this.edges.forEach(function(e) {
|
||||
if (edge.id === e.id) { exists = true; }
|
||||
});
|
||||
|
||||
if (!exists) {
|
||||
this.edges.push(edge);
|
||||
}
|
||||
|
||||
if (typeof(this.adjacency[edge.source.id]) === 'undefined') {
|
||||
this.adjacency[edge.source.id] = {};
|
||||
}
|
||||
if (typeof(this.adjacency[edge.source.id][edge.target.id]) === 'undefined') {
|
||||
this.adjacency[edge.source.id][edge.target.id] = [];
|
||||
}
|
||||
|
||||
exists = false;
|
||||
this.adjacency[edge.source.id][edge.target.id].forEach(function(e) {
|
||||
if (edge.id === e.id) { exists = true; }
|
||||
});
|
||||
|
||||
if (!exists) {
|
||||
this.adjacency[edge.source.id][edge.target.id].push(edge);
|
||||
}
|
||||
|
||||
this.notify();
|
||||
return edge;
|
||||
};
|
||||
|
||||
Graph.prototype.newNode = function(data) {
|
||||
var node = new Node(this.nextNodeId++, data);
|
||||
this.addNode(node);
|
||||
return node;
|
||||
};
|
||||
|
||||
Graph.prototype.newEdge = function(source, target, data) {
|
||||
var edge = new Edge(this.nextEdgeId++, source, target, data);
|
||||
this.addEdge(edge);
|
||||
return edge;
|
||||
};
|
||||
|
||||
// find the edges from node1 to node2
|
||||
Graph.prototype.getEdges = function(node1, node2) {
|
||||
if (typeof(this.adjacency[node1.id]) !== 'undefined'
|
||||
&& typeof(this.adjacency[node1.id][node2.id]) !== 'undefined') {
|
||||
return this.adjacency[node1.id][node2.id];
|
||||
}
|
||||
|
||||
return [];
|
||||
};
|
||||
|
||||
// remove a node and it's associated edges from the graph
|
||||
Graph.prototype.removeNode = function(node) {
|
||||
if (typeof(this.nodeSet[node.id]) !== 'undefined') {
|
||||
delete this.nodeSet[node.id];
|
||||
}
|
||||
|
||||
for (var i = this.nodes.length - 1; i >= 0; i--) {
|
||||
if (this.nodes[i].id === node.id) {
|
||||
this.nodes.splice(i, 1);
|
||||
}
|
||||
}
|
||||
|
||||
this.detachNode(node);
|
||||
|
||||
};
|
||||
|
||||
// removes edges associated with a given node
|
||||
Graph.prototype.detachNode = function(node) {
|
||||
var tmpEdges = this.edges.slice();
|
||||
tmpEdges.forEach(function(e) {
|
||||
if (e.source.id === node.id || e.target.id === node.id) {
|
||||
this.removeEdge(e);
|
||||
}
|
||||
}, this);
|
||||
|
||||
this.notify();
|
||||
};
|
||||
|
||||
// remove a node and it's associated edges from the graph
|
||||
Graph.prototype.removeEdge = function(edge) {
|
||||
for (var i = this.edges.length - 1; i >= 0; i--) {
|
||||
if (this.edges[i].id === edge.id) {
|
||||
this.edges.splice(i, 1);
|
||||
}
|
||||
}
|
||||
|
||||
for (var x in this.adjacency) {
|
||||
for (var y in this.adjacency[x]) {
|
||||
var edges = this.adjacency[x][y];
|
||||
|
||||
for (var j=edges.length - 1; j>=0; j--) {
|
||||
if (this.adjacency[x][y][j].id === edge.id) {
|
||||
this.adjacency[x][y].splice(j, 1);
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
this.notify();
|
||||
};
|
||||
|
||||
/* Merge a list of nodes and edges into the current graph. eg.
|
||||
var o = {
|
||||
nodes: [
|
||||
{id: 123, data: {type: 'user', userid: 123, displayname: 'aaa'}},
|
||||
{id: 234, data: {type: 'user', userid: 234, displayname: 'bbb'}}
|
||||
],
|
||||
edges: [
|
||||
{from: 0, to: 1, type: 'submitted_design', directed: true, data: {weight: }}
|
||||
]
|
||||
}
|
||||
*/
|
||||
Graph.prototype.merge = function(data) {
|
||||
var nodes = [];
|
||||
data.nodes.forEach(function(n) {
|
||||
nodes.push(this.addNode(new Node(n.id, n.data)));
|
||||
}, this);
|
||||
|
||||
data.edges.forEach(function(e) {
|
||||
var from = nodes[e.from];
|
||||
var to = nodes[e.to];
|
||||
|
||||
var id = (e.directed)
|
||||
? (id = e.type + "-" + from.id + "-" + to.id)
|
||||
: (from.id < to.id) // normalise id for non-directed edges
|
||||
? e.type + "-" + from.id + "-" + to.id
|
||||
: e.type + "-" + to.id + "-" + from.id;
|
||||
|
||||
var edge = this.addEdge(new Edge(id, from, to, e.data));
|
||||
edge.data.type = e.type;
|
||||
}, this);
|
||||
};
|
||||
|
||||
Graph.prototype.filterNodes = function(fn) {
|
||||
var tmpNodes = this.nodes.slice();
|
||||
tmpNodes.forEach(function(n) {
|
||||
if (!fn(n)) {
|
||||
this.removeNode(n);
|
||||
}
|
||||
}, this);
|
||||
};
|
||||
|
||||
Graph.prototype.filterEdges = function(fn) {
|
||||
var tmpEdges = this.edges.slice();
|
||||
tmpEdges.forEach(function(e) {
|
||||
if (!fn(e)) {
|
||||
this.removeEdge(e);
|
||||
}
|
||||
}, this);
|
||||
};
|
||||
|
||||
|
||||
Graph.prototype.addGraphListener = function(obj) {
|
||||
this.eventListeners.push(obj);
|
||||
};
|
||||
|
||||
Graph.prototype.notify = function() {
|
||||
this.eventListeners.forEach(function(obj){
|
||||
obj.graphChanged();
|
||||
});
|
||||
};
|
||||
|
||||
// -----------
|
||||
var Layout = {};
|
||||
Layout.ForceDirected = function(graph, stiffness, repulsion, damping) {
|
||||
this.graph = graph;
|
||||
this.stiffness = stiffness; // spring stiffness constant
|
||||
this.repulsion = repulsion; // repulsion constant
|
||||
this.damping = damping; // velocity damping factor
|
||||
|
||||
this.nodePoints = {}; // keep track of points associated with nodes
|
||||
this.edgeSprings = {}; // keep track of springs associated with edges
|
||||
};
|
||||
|
||||
Layout.ForceDirected.prototype.point = function(node) {
|
||||
if (typeof(this.nodePoints[node.id]) === 'undefined') {
|
||||
var mass = typeof(node.data.mass) !== 'undefined' ? node.data.mass : 1.0;
|
||||
this.nodePoints[node.id] = new Layout.ForceDirected.Point(Vector.random(), mass);
|
||||
}
|
||||
|
||||
return this.nodePoints[node.id];
|
||||
};
|
||||
|
||||
Layout.ForceDirected.prototype.spring = function(edge) {
|
||||
if (typeof(this.edgeSprings[edge.id]) === 'undefined') {
|
||||
var length = typeof(edge.data.length) !== 'undefined' ? edge.data.length : 1.0;
|
||||
|
||||
var existingSpring = false;
|
||||
|
||||
var from = this.graph.getEdges(edge.source, edge.target);
|
||||
from.forEach(function(e) {
|
||||
if (existingSpring === false && typeof(this.edgeSprings[e.id]) !== 'undefined') {
|
||||
existingSpring = this.edgeSprings[e.id];
|
||||
}
|
||||
}, this);
|
||||
|
||||
if (existingSpring !== false) {
|
||||
return new Layout.ForceDirected.Spring(existingSpring.point1, existingSpring.point2, 0.0, 0.0);
|
||||
}
|
||||
|
||||
var to = this.graph.getEdges(edge.target, edge.source);
|
||||
from.forEach(function(e){
|
||||
if (existingSpring === false && typeof(this.edgeSprings[e.id]) !== 'undefined') {
|
||||
existingSpring = this.edgeSprings[e.id];
|
||||
}
|
||||
}, this);
|
||||
|
||||
if (existingSpring !== false) {
|
||||
return new Layout.ForceDirected.Spring(existingSpring.point2, existingSpring.point1, 0.0, 0.0);
|
||||
}
|
||||
|
||||
this.edgeSprings[edge.id] = new Layout.ForceDirected.Spring(
|
||||
this.point(edge.source), this.point(edge.target), length, this.stiffness
|
||||
);
|
||||
}
|
||||
|
||||
return this.edgeSprings[edge.id];
|
||||
};
|
||||
|
||||
// callback should accept two arguments: Node, Point
|
||||
Layout.ForceDirected.prototype.eachNode = function(callback) {
|
||||
var t = this;
|
||||
this.graph.nodes.forEach(function(n){
|
||||
callback.call(t, n, t.point(n));
|
||||
});
|
||||
};
|
||||
|
||||
// callback should accept two arguments: Edge, Spring
|
||||
Layout.ForceDirected.prototype.eachEdge = function(callback) {
|
||||
var t = this;
|
||||
this.graph.edges.forEach(function(e){
|
||||
callback.call(t, e, t.spring(e));
|
||||
});
|
||||
};
|
||||
|
||||
// callback should accept one argument: Spring
|
||||
Layout.ForceDirected.prototype.eachSpring = function(callback) {
|
||||
var t = this;
|
||||
this.graph.edges.forEach(function(e){
|
||||
callback.call(t, t.spring(e));
|
||||
});
|
||||
};
|
||||
|
||||
|
||||
// Physics stuff
|
||||
Layout.ForceDirected.prototype.applyCoulombsLaw = function() {
|
||||
this.eachNode(function(n1, point1) {
|
||||
this.eachNode(function(n2, point2) {
|
||||
if (point1 !== point2)
|
||||
{
|
||||
var d = point1.p.subtract(point2.p);
|
||||
var distance = d.magnitude() + 0.1; // avoid massive forces at small distances (and divide by zero)
|
||||
var direction = d.normalise();
|
||||
|
||||
// apply force to each end point
|
||||
point1.applyForce(direction.multiply(this.repulsion).divide(distance * distance * 0.5));
|
||||
point2.applyForce(direction.multiply(this.repulsion).divide(distance * distance * -0.5));
|
||||
}
|
||||
});
|
||||
});
|
||||
};
|
||||
|
||||
Layout.ForceDirected.prototype.applyHookesLaw = function() {
|
||||
this.eachSpring(function(spring){
|
||||
var d = spring.point2.p.subtract(spring.point1.p); // the direction of the spring
|
||||
var displacement = spring.length - d.magnitude();
|
||||
var direction = d.normalise();
|
||||
|
||||
// apply force to each end point
|
||||
spring.point1.applyForce(direction.multiply(spring.k * displacement * -0.5));
|
||||
spring.point2.applyForce(direction.multiply(spring.k * displacement * 0.5));
|
||||
});
|
||||
};
|
||||
|
||||
Layout.ForceDirected.prototype.attractToCentre = function() {
|
||||
this.eachNode(function(node, point) {
|
||||
var direction = point.p.multiply(-1.0);
|
||||
point.applyForce(direction.multiply(this.repulsion / 50.0));
|
||||
});
|
||||
};
|
||||
|
||||
|
||||
Layout.ForceDirected.prototype.updateVelocity = function(timestep) {
|
||||
this.eachNode(function(node, point) {
|
||||
// Is this, along with updatePosition below, the only places that your
|
||||
// integration code exist?
|
||||
point.v = point.v.add(point.a.multiply(timestep)).multiply(this.damping);
|
||||
point.a = new Vector(0,0);
|
||||
});
|
||||
};
|
||||
|
||||
Layout.ForceDirected.prototype.updatePosition = function(timestep) {
|
||||
this.eachNode(function(node, point) {
|
||||
// Same question as above; along with updateVelocity, is this all of
|
||||
// your integration code?
|
||||
point.p = point.p.add(point.v.multiply(timestep));
|
||||
});
|
||||
};
|
||||
|
||||
// Calculate the total kinetic energy of the system
|
||||
Layout.ForceDirected.prototype.totalEnergy = function(timestep) {
|
||||
var energy = 0.0;
|
||||
this.eachNode(function(node, point) {
|
||||
var speed = point.v.magnitude();
|
||||
energy += 0.5 * point.m * speed * speed;
|
||||
});
|
||||
|
||||
return energy;
|
||||
};
|
||||
|
||||
var __bind = function(fn, me){ return function(){ return fn.apply(me, arguments); }; }; // stolen from coffeescript, thanks jashkenas! ;-)
|
||||
|
||||
Layout.requestAnimationFrame = __bind(window.requestAnimationFrame ||
|
||||
window.webkitRequestAnimationFrame ||
|
||||
window.mozRequestAnimationFrame ||
|
||||
window.oRequestAnimationFrame ||
|
||||
window.msRequestAnimationFrame ||
|
||||
function(callback, element) {
|
||||
window.setTimeout(callback, 10);
|
||||
}, window);
|
||||
|
||||
|
||||
// start simulation
|
||||
Layout.ForceDirected.prototype.start = function(interval, render, done) {
|
||||
var t = this;
|
||||
|
||||
if (this._started) return;
|
||||
this._started = true;
|
||||
|
||||
Layout.requestAnimationFrame(function step() {
|
||||
t.applyCoulombsLaw();
|
||||
t.applyHookesLaw();
|
||||
t.attractToCentre();
|
||||
t.updateVelocity(0.03);
|
||||
t.updatePosition(0.03);
|
||||
|
||||
if (typeof(render) !== 'undefined')
|
||||
render();
|
||||
|
||||
// stop simulation when energy of the system goes below a threshold
|
||||
if (t.totalEnergy() < 0.01) {
|
||||
t._started = false;
|
||||
if (typeof(done) !== 'undefined') { done(); }
|
||||
} else {
|
||||
Layout.requestAnimationFrame(step);
|
||||
}
|
||||
});
|
||||
};
|
||||
|
||||
// Find the nearest point to a particular position
|
||||
Layout.ForceDirected.prototype.nearest = function(pos) {
|
||||
var min = {node: null, point: null, distance: null};
|
||||
var t = this;
|
||||
this.graph.nodes.forEach(function(n){
|
||||
var point = t.point(n);
|
||||
var distance = point.p.subtract(pos).magnitude();
|
||||
|
||||
if (min.distance === null || distance < min.distance) {
|
||||
min = {node: n, point: point, distance: distance};
|
||||
}
|
||||
});
|
||||
|
||||
return min;
|
||||
};
|
||||
|
||||
// returns [bottomleft, topright]
|
||||
Layout.ForceDirected.prototype.getBoundingBox = function() {
|
||||
var bottomleft = new Vector(-2,-2);
|
||||
var topright = new Vector(2,2);
|
||||
|
||||
this.eachNode(function(n, point) {
|
||||
if (point.p.x < bottomleft.x) {
|
||||
bottomleft.x = point.p.x;
|
||||
}
|
||||
if (point.p.y < bottomleft.y) {
|
||||
bottomleft.y = point.p.y;
|
||||
}
|
||||
if (point.p.x > topright.x) {
|
||||
topright.x = point.p.x;
|
||||
}
|
||||
if (point.p.y > topright.y) {
|
||||
topright.y = point.p.y;
|
||||
}
|
||||
});
|
||||
|
||||
var padding = topright.subtract(bottomleft).multiply(0.07); // ~5% padding
|
||||
|
||||
return {bottomleft: bottomleft.subtract(padding), topright: topright.add(padding)};
|
||||
};
|
||||
|
||||
|
||||
// Vector
|
||||
Vector = function(x, y) {
|
||||
this.x = x;
|
||||
this.y = y;
|
||||
};
|
||||
|
||||
Vector.random = function() {
|
||||
return new Vector(10.0 * (Math.random() - 0.5), 10.0 * (Math.random() - 0.5));
|
||||
};
|
||||
|
||||
Vector.prototype.add = function(v2) {
|
||||
return new Vector(this.x + v2.x, this.y + v2.y);
|
||||
};
|
||||
|
||||
Vector.prototype.subtract = function(v2) {
|
||||
return new Vector(this.x - v2.x, this.y - v2.y);
|
||||
};
|
||||
|
||||
Vector.prototype.multiply = function(n) {
|
||||
return new Vector(this.x * n, this.y * n);
|
||||
};
|
||||
|
||||
Vector.prototype.divide = function(n) {
|
||||
return new Vector((this.x / n) || 0, (this.y / n) || 0); // Avoid divide by zero errors..
|
||||
};
|
||||
|
||||
Vector.prototype.magnitude = function() {
|
||||
return Math.sqrt(this.x*this.x + this.y*this.y);
|
||||
};
|
||||
|
||||
Vector.prototype.normal = function() {
|
||||
return new Vector(-this.y, this.x);
|
||||
};
|
||||
|
||||
Vector.prototype.normalise = function() {
|
||||
return this.divide(this.magnitude());
|
||||
};
|
||||
|
||||
// Point
|
||||
Layout.ForceDirected.Point = function(position, mass) {
|
||||
this.p = position; // position
|
||||
this.m = mass; // mass
|
||||
this.v = new Vector(0, 0); // velocity
|
||||
this.a = new Vector(0, 0); // acceleration
|
||||
};
|
||||
|
||||
Layout.ForceDirected.Point.prototype.applyForce = function(force) {
|
||||
this.a = this.a.add(force.divide(this.m));
|
||||
};
|
||||
|
||||
// Spring
|
||||
Layout.ForceDirected.Spring = function(point1, point2, length, k) {
|
||||
this.point1 = point1;
|
||||
this.point2 = point2;
|
||||
this.length = length; // spring length at rest
|
||||
this.k = k; // spring constant (See Hooke's law) .. how stiff the spring is
|
||||
};
|
||||
|
||||
// Layout.ForceDirected.Spring.prototype.distanceToPoint = function(point)
|
||||
// {
|
||||
// // hardcore vector arithmetic.. ohh yeah!
|
||||
// // .. see http://stackoverflow.com/questions/849211/shortest-distance-between-a-point-and-a-line-segment/865080#865080
|
||||
// var n = this.point2.p.subtract(this.point1.p).normalise().normal();
|
||||
// var ac = point.p.subtract(this.point1.p);
|
||||
// return Math.abs(ac.x * n.x + ac.y * n.y);
|
||||
// };
|
||||
|
||||
// Renderer handles the layout rendering loop
|
||||
function Renderer(interval, layout, clear, drawEdge, drawNode) {
|
||||
this.interval = interval;
|
||||
this.layout = layout;
|
||||
this.clear = clear;
|
||||
this.drawEdge = drawEdge;
|
||||
this.drawNode = drawNode;
|
||||
|
||||
this.layout.graph.addGraphListener(this);
|
||||
}
|
||||
|
||||
Renderer.prototype.graphChanged = function(e) {
|
||||
this.start();
|
||||
};
|
||||
|
||||
Renderer.prototype.start = function() {
|
||||
var t = this;
|
||||
this.layout.start(50, function render() {
|
||||
t.clear();
|
||||
|
||||
t.layout.eachEdge(function(edge, spring) {
|
||||
t.drawEdge(edge, spring.point1.p, spring.point2.p);
|
||||
});
|
||||
|
||||
t.layout.eachNode(function(node, point) {
|
||||
t.drawNode(node, point.p);
|
||||
});
|
||||
});
|
||||
};
|
||||
|
||||
Loading…
Reference in New Issue
Block a user