polygon-offset/example/polygon_control.js

Polygon offsetting algorithm, aimed for use with leaflet

L.EditControl = L.Control.extend({

  options: {
    position: 'topleft',
    callback: null,
    kind: '',
    html: ''
  },

  onAdd: function (map) {
    var container = L.DomUtil.create('div', 'leaflet-control leaflet-bar'),
        link = L.DomUtil.create('a', '', container);

    link.href = '#';
    link.title = 'Create a new ' + this.options.kind;
    link.innerHTML = this.options.html;
    L.DomEvent.on(link, 'click', L.DomEvent.stop)
              .on(link, 'click', function () {
                window.LAYER = this.options.callback.call(map.editTools);
              }, this);

    return container;
  }

});

L.NewPolygonControl = L.EditControl.extend({
  options: {
    position: 'topleft',
    kind: 'polygon',
    html: '∆'
  }
});

L.NewLineControl = L.EditControl.extend({
  options: {
    position: 'topleft',
    kind: 'polyline',
    html: '/'
  }
});

L.NewPointControl = L.EditControl.extend({
  options: {
    position: 'topleft',
    kind: 'point',
    html: '●'
  }
});