Pathfinding.GraphUpdateObject.WillUpdateNode C# (CSharp) Method

        public virtual void WillUpdateNode(Node node)
        {
            if (trackChangedNodes && node != null) {
                if (changedNodes == null) { changedNodes = new List<Node>(); backupData = new List<ulong>(); backupPositionData = new List<Int3>(); }
                changedNodes.Add (node);
                backupPositionData.Add (node.position);
                backupData.Add ((ulong)node.penalty<<32 | (ulong)node.flags);
            }
        }

        public static void UpdateArea(GraphUpdateObject o, INavmesh graph)
        {
            Bounds bounds = o.bounds;

            // Bounding rectangle with floating point coordinates
            Rect r = Rect.MinMaxRect(bounds.min.x, bounds.min.z, bounds.max.x, bounds.max.z);

            // Bounding rectangle with int coordinates
            var r2 = new IntRect(
                Mathf.FloorToInt(bounds.min.x * Int3.Precision),
                Mathf.FloorToInt(bounds.min.z * Int3.Precision),
                Mathf.FloorToInt(bounds.max.x * Int3.Precision),
                Mathf.FloorToInt(bounds.max.z * Int3.Precision)
                );

            // Corners of the bounding rectangle
            var a = new Int3(r2.xmin, 0, r2.ymin);
            var b = new Int3(r2.xmin, 0, r2.ymax);
            var c = new Int3(r2.xmax, 0, r2.ymin);
            var d = new Int3(r2.xmax, 0, r2.ymax);

            var ymin = ((Int3)bounds.min).y;
            var ymax = ((Int3)bounds.max).y;

            // Loop through all nodes
            graph.GetNodes(_node => {
                var node = _node as TriangleMeshNode;

                bool inside = false;

                int allLeft   = 0;
                int allRight  = 0;
                int allTop    = 0;
                int allBottom = 0;

                // Check bounding box rect in XZ plane
                for (int v = 0; v < 3; v++)
                {
                    Int3 p   = node.GetVertex(v);
                    var vert = (Vector3)p;

                    if (r2.Contains(p.x, p.z))
                    {
                        inside = true;
                        break;
                    }

                    if (vert.x < r.xMin)
                    {
                        allLeft++;
                    }
                    if (vert.x > r.xMax)
                    {
                        allRight++;
                    }
                    if (vert.z < r.yMin)
                    {
                        allTop++;
                    }
                    if (vert.z > r.yMax)
                    {
                        allBottom++;
                    }
                }

                if (!inside)
                {
                    if (allLeft == 3 || allRight == 3 || allTop == 3 || allBottom == 3)
                    {
                        return(true);
                    }
                }

                // Check if the polygon edges intersect the bounding rect
                for (int v = 0; v < 3; v++)
                {
                    int v2 = v > 1 ? 0 : v + 1;

                    Int3 vert1 = node.GetVertex(v);
                    Int3 vert2 = node.GetVertex(v2);

                    if (VectorMath.SegmentsIntersectXZ(a, b, vert1, vert2))
                    {
                        inside = true; break;
                    }
                    if (VectorMath.SegmentsIntersectXZ(a, c, vert1, vert2))
                    {
                        inside = true; break;
                    }
                    if (VectorMath.SegmentsIntersectXZ(c, d, vert1, vert2))
                    {
                        inside = true; break;
                    }
                    if (VectorMath.SegmentsIntersectXZ(d, b, vert1, vert2))
                    {
                        inside = true; break;
                    }
                }

                // Check if the node contains any corner of the bounding rect
                if (inside || node.ContainsPoint(a) || node.ContainsPoint(b) || node.ContainsPoint(c) || node.ContainsPoint(d))
                {
                    inside = true;
                }

                if (!inside)
                {
                    return(true);
                }

                int allAbove = 0;
                int allBelow = 0;

                // Check y coordinate
                for (int v = 0; v < 3; v++)
                {
                    Int3 p = node.GetVertex(v);
                    if (p.y < ymin)
                    {
                        allBelow++;
                    }
                    if (p.y > ymax)
                    {
                        allAbove++;
                    }
                }

                // Polygon is either completely above the bounding box or completely below it
                if (allBelow == 3 || allAbove == 3)
                {
                    return(true);
                }

                // Triangle is inside the bounding box!
                // Update it!
                o.WillUpdateNode(node);
                o.Apply(node);
                return(true);
            });
        }