Merge remote-tracking branch 'origin/v4' into v4

lib/network/modules/components/physics/BarnesHutSolver.js

@@ -68,17 +68,7 @@ class BarnesHutSolver {
       // original condition : s/d < theta = passed  ===  d/s > 1/theta = passed
       // calcSize = 1/s --> d * 1/s > 1/theta = passed
       if (distance * parentBranch.calcSize > this.thetaInversed) {
-        // duplicate code to reduce function calls to speed up program
-        if (distance === 0) {
-          distance = 0.1 * Math.random();
-          dx = distance;
-        }
-        var gravityForce = this.options.gravitationalConstant * parentBranch.mass * node.options.mass / (distance * distance * distance);
-        var fx = dx * gravityForce;
-        var fy = dy * gravityForce;
-
-        this.physicsBody.forces[node.id].x += fx;
-        this.physicsBody.forces[node.id].y += fy;
+        this._calculateForces(distance, dx, dy, node, parentBranch);
       }
       else {
         // Did not pass the condition, go into children if available
@@ -90,17 +80,7 @@ class BarnesHutSolver {
         }
         else { // parentBranch must have only one node, if it was empty we wouldnt be here
           if (parentBranch.children.data.id != node.id) { // if it is not self
-            // duplicate code to reduce function calls to speed up program
-            if (distance === 0) {
-              distance = 0.5 * Math.random();
-              dx = distance;
-            }
-            var gravityForce = this.options.gravitationalConstant * parentBranch.mass * node.options.mass / (distance * distance * distance);
-            var fx = dx * gravityForce;
-            var fy = dy * gravityForce;
-
-            this.physicsBody.forces[node.id].x += fx;
-            this.physicsBody.forces[node.id].y += fy;
+            this._calculateForces(distance, dx, dy, node, parentBranch);
           }
         }
       }
@@ -108,6 +88,31 @@ class BarnesHutSolver {
   }
 
 
+  /**
+   * Calculate the forces based on the distance.
+   *
+   * @param distance
+   * @param dx
+   * @param dy
+   * @param node
+   * @param parentBranch
+   * @private
+   */
+  _calculateForces(distance, dx, dy, node, parentBranch) {
+    // duplicate code to reduce function calls to speed up program
+    if (distance === 0) {
+      distance = 0.1 * Math.random();
+      dx = distance;
+    }
+    var gravityForce = this.options.gravitationalConstant * parentBranch.mass * node.options.mass / (distance * distance * distance);
+    var fx = dx * gravityForce;
+    var fy = dy * gravityForce;
+
+    this.physicsBody.forces[node.id].x += fx;
+    this.physicsBody.forces[node.id].y += fy;
+  }
+
+
   /**
    * This function constructs the barnesHut tree recursively. It creates the root, splits it and starts placing the nodes.
    *