Added Point.GetCentroid.

v3/src/geom/point/GetCentroid.js

@@ -0,0 +1,38 @@
+var Point = require('./Point');
+
+var GetCentroid = function (points, out)
+{
+    if (out === undefined) { out = new Point(); }
+
+    if (!Array.isArray(points))
+    {
+        throw new Error('GetCentroid points argument must be an array');
+    }
+
+    var len = points.length;
+
+    if (len < 1)
+    {
+        throw new Error('GetCentroid points array must not be empty');
+    }
+    else if (len === 1)
+    {
+        out.x = points[0].x;
+        out.y = points[0].y;
+    }
+    else
+    {
+        for (var i = 0; i < len; i++)
+        {
+            out.x += points[i].x;
+            out.y += points[i].y;
+        }
+
+        out.x /= len;
+        out.y /= len;
+    }
+
+    return out;
+};
+
+module.exports = GetCentroid;

v3/src/geom/point/index.js

@@ -11,6 +11,7 @@ Point.Divide = require('./Divide');
 Point.Dot = require('./Dot');
 Point.Equals = require('./Equals');
 Point.Floor = require('./Floor');
+Point.GetCentroid = require('./GetCentroid');
 Point.GetMagnitude = require('./GetMagnitude');
 Point.GetMagnitudeSq = require('./GetMagnitudeSq');
 Point.Interpolate = require('./Interpolate');