litegraph.js

A library in Javascript to create graphs in the browser similar to PD. Nodes can be programmed easily and it includes an editor to construct the graphs.

It can be integrated easily in any existing web applications and graphs can be run without the need of the editor.

Creating a Graph

You can create graphs from the editor (and store them in JSON) or directly from code:

var graph = new LGraph();
var node = LiteGraph.createNode("basic/const");
var node2 = LiteGraph.createNode("basic/watch");
graph.add( node );
graph.add( node2 );
node.connect(0, node2, 0); //connect node slot 0 to node2 slot 0

graph.runStep(1); //execute one cycle

How to code a new Node type

Here is an example of how to build a node that sums two inputs:

//node constructor class
function MyAddNode()
{
  this.addInput("A","number");
  this.addInput("B","number");
  this.addOutput("A+B","number");
}

//name to show
MyAddNode.title = "Sum";

//function to call when the node is executed
MyAddNode.prototype.onExecute = function()
{
  var A = this.getInputData(0);
  if( A === undefined )
    A = 0;
  var B = this.getInputData(1);
  if( B === undefined )
    B = 0;
  this.setOutputData( 0, A + B );
}

//register in the system
LiteGraph.registerNodeType("basic/sum", MyAddNode );