First commit.

Signed-off-by: Chen Xiao <abigwc@gmail.com>

client/node_modules/layout-base/src/fd/FDLayoutNode.js

@@ -0,0 +1,42 @@
+var LNode = require('../LNode');
+
+function FDLayoutNode(gm, loc, size, vNode) {
+  // alternative constructor is handled inside LNode
+  LNode.call(this, gm, loc, size, vNode);
+  //Spring, repulsion and gravitational forces acting on this node
+  this.springForceX = 0;
+  this.springForceY = 0;
+  this.repulsionForceX = 0;
+  this.repulsionForceY = 0;
+  this.gravitationForceX = 0;
+  this.gravitationForceY = 0;
+  //Amount by which this node is to be moved in this iteration
+  this.displacementX = 0;
+  this.displacementY = 0;
+
+  //Start and finish grid coordinates that this node is fallen into
+  this.startX = 0;
+  this.finishX = 0;
+  this.startY = 0;
+  this.finishY = 0;
+
+  //Geometric neighbors of this node
+  this.surrounding = [];
+}
+
+FDLayoutNode.prototype = Object.create(LNode.prototype);
+
+for (var prop in LNode) {
+  FDLayoutNode[prop] = LNode[prop];
+}
+
+FDLayoutNode.prototype.setGridCoordinates = function (_startX, _finishX, _startY, _finishY)
+{
+  this.startX = _startX;
+  this.finishX = _finishX;
+  this.startY = _startY;
+  this.finishY = _finishY;
+
+};
+
+module.exports = FDLayoutNode;