JavascriptVoronoi
A Javascript implementation of Steven J. Fortune's algorithm to efficiently compute Voronoi diagrams. The Voronoi object's purpose is to solely compute a Voronoi diagram, it is completely standalone, with no dependency on external code: it contains no rendering code: that is left to the user of the library.
Core files
 rhillvoronoicore.js
Where the Voronoi object is implemented. This is a standalone library, there is no dependency.
 rhillvoronoicore.min.js
The minimized version (using YUI compressor)
Demo files
 rhillvoronoidemo1.html
 rhillvoronoidemo2.html
 rhillvoronoidemo3.php
 rhillvoronoidemo4.html
 rhillvoronoidemo5.html
Demo pages to demonstrate usage of the Voronoi object.
 excanvas/*
Used by demo pages.
ExplorerCanvas, giving preHTML5 Internet Explorer the ability to make sense of HTML5's canvas element. Pulled from http://code.google.com/p/explorercanvas/
 mootools/*
Used by rhillvoronoidemo3.php
 Above pages available at http://www.raymondhill.net/voronoi/
Main object: Voronoi
A Javascript object which allows to compute a Voronoi diagram. The Voronoi object doesn't render the resulting Voronoi diagram, the user is responsible for rendering the diagram.
Usage
Roughly:
var voronoi = ;var bbox = xl: 0 xr: 800 yt: 0 yb: 600; // xl is xleft, xr is xright, yt is ytop, and yb is ybottomvar sites = x: 200 y: 200 x: 50 y: 250 x: 400 y: 100 /* , ... */ ;// a 'vertex' is an object exhibiting 'x' and 'y' properties. The// Voronoi object will add a unique 'voronoiId' property to all// sites. The 'voronoiId' can be used as a key to lookup the associated cell// in diagram.cells.var diagram = voronoi;
The returned 'diagram' variable is a Javascript object with the following properties:
diagram.vertices
An array of unordered, unique Voronoi.Vertex
objects making up the
Voronoi diagram. Each Voronoi.Vertex
object in the list is shared by
many Voronoi.Edge
objects.
diagram.edges
An array of unordered, unique Voronoi.Edge
objects making up the
Voronoi diagram. Voronoi.Edges
are defined by two vertices,
va
and vb
, which vertices are shared by connected edges. This mean
that if you change one vertex belonging to an edge, other connected edges
will also be changed.
diagram.cells
An array of Voronoi.Cell
objects making up the Voronoi diagram. A
Voronoi.Cell
object might have an empty array of halfedges
,
meaning no Voronoi cell could be computed for a particular cell.
diagram.execTime
The time it took to compute the Voronoi diagram, in milliseconds.
Added on October 12, 2013: In order to help improve performance,
Voronoi.recycle()
has been added to allow the recycling of a returned Voronoi
diagram. Usage:
var diagram;...// some kind of loop starting here (whether outright or through a timer)...voronoi;// diagram.vertices, diagram.edges and diagram.cells can no longer be used!diagram = voronoi;// do stuff with content of `diagram`...
This new method helps performance significantly when recomputing a Voronoi diagram, as it saves on memory allocation, and associated garbage collection.
Public objects
Voronoi
The Voronoi
object which computes a Voronoi diagram.
Voronoi.Vertex

x
: no explanation required. 
y
: no explanation required.
Voronoi.Edge

lSite
: the Voronoi site object at the left of thisVoronoi.Edge
object. The site object is just a reference to a site in the array of sites supplied by the user whenVoronoi.compute()
was called. 
rSite
: the Voronoi site object at the right of thisVoronoi.Edge
object (can be null, when this is a border edge). The site object is just a reference to a site in the array of sites supplied by the user whenVoronoi.compute()
was called. 
va
: aVoronoi.Vertex
object with anx
and ay
property defining the start point (relative to the Voronoi site on the left) of thisVoronoi.Edge
object. 
vb
: aVoronoi.Vertex
object with anx
and ay
property defining the end point (relative to Voronoi site on the left) of thisVoronoi.Edge
object.
Voronoi.Cell

site
: the Voronoi site object associated with the Voronoi cell. 
halfedges
: an array ofVoronoi.Halfedge
objects, ordered counterclockwise, defining the polygon for this Voronoi cell.
Voronoi.Halfedge

site
: the Voronoi site object owning thisVoronoi.Halfedge
object. 
edge
: a reference to the uniqueVoronoi.Edge
object underlying thisVoronoi.Halfedge
object. 
getStartpoint()
: a method returning aVoronoi.Vertex
of the start point of this halfedge. Keep in mind halfedges are always counterclockwise. 
getEndpoint()
: a method returning aVoronoi.Vertex
object with anx
and ay
property for the end point of this halfedge. Keep in mind halfedges are always counterclockwise.
License
Copyright (c) 20102013 Raymond Hill https://github.com/gorhill/JavascriptVoronoi
Licensed under The MIT License http://en.wikipedia.org/wiki/MIT_License
Permission is hereby granted, free of charge, to any person 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.