public List <Vector2> Region(Vector2 p)
        {
            Site site = _sitesIndexedByLocation [p];

            if (site == null)
            {
                return(new List <Vector2> ());
            }
            return(site.GenerateRegion(_plotBounds));
        }
        public void LloydRelaxation(int nbIterations)
        {
            // Reapeat the whole process for the number of iterations asked
            for (int i = 0; i < nbIterations; i++)
            {
                List <Vector2> newPoints = new List <Vector2>();
                // Go thourgh all sites
                SitesList.ResetListIndex();
                Site site = SitesList.Next();

                while (site != null)
                {
                    // Loop all corners of the site to calculate the centroid
                    List <Vector2> region = site.GenerateRegion(plotBounds);
                    if (region.Count < 1)
                    {
                        site = SitesList.Next();
                        continue;
                    }

                    Vector2 centroid   = Vector2.zero;
                    float   signedArea = 0;
                    float   x0         = 0;
                    float   y0         = 0;
                    float   x1         = 0;
                    float   y1         = 0;
                    float   a          = 0;
                    // For all vertices except last
                    for (int j = 0; j < region.Count - 1; j++)
                    {
                        x0          = region[j].x;
                        y0          = region[j].y;
                        x1          = region[j + 1].x;
                        y1          = region[j + 1].y;
                        a           = x0 * y1 - x1 * y0;
                        signedArea += a;
                        centroid.x += (x0 + x1) * a;
                        centroid.y += (y0 + y1) * a;
                    }
                    // Do last vertex
                    x0          = region[region.Count - 1].x;
                    y0          = region[region.Count - 1].y;
                    x1          = region[0].x;
                    y1          = region[0].y;
                    a           = x0 * y1 - x1 * y0;
                    signedArea += a;
                    centroid.x += (x0 + x1) * a;
                    centroid.y += (y0 + y1) * a;

                    signedArea *= 0.5f;
                    centroid.x /= (6 * signedArea);
                    centroid.y /= (6 * signedArea);
                    // Move site to the centroid of its Voronoi cell
                    newPoints.Add(centroid);
                    site = SitesList.Next();
                }

                // Between each replacement of the cendroid of the cell,
                // we need to recompute Voronoi diagram:
                Rect origPlotBounds = this.plotBounds;
                Dispose();
                Init(newPoints, origPlotBounds);
            }
        }