ET/Unity/Assets/Plugins/AstarPathfindingProject/Pathfinders/ABPath.cs

using UnityEngine;
using System.Collections.Generic;

namespace Pathfinding {
	/// <summary>
	/// Basic path, finds the shortest path from A to B.
	///
	/// This is the most basic path object it will try to find the shortest path between two points.
	/// Many other path types inherit from this type.
	/// See: Seeker.StartPath
	/// See: calling-pathfinding (view in online documentation for working links)
	/// See: getstarted (view in online documentation for working links)
	/// </summary>
	public class ABPath : Path {
		/// <summary>Start node of the path</summary>
		public GraphNode startNode;

		/// <summary>End node of the path</summary>
		public GraphNode endNode;

		/// <summary>Start Point exactly as in the path request</summary>
		public Vector3 originalStartPoint;

		/// <summary>End Point exactly as in the path request</summary>
		public Vector3 originalEndPoint;

		/// <summary>
		/// Start point of the path.
		/// This is the closest point on the <see cref="startNode"/> to <see cref="originalStartPoint"/>
		/// </summary>
		public Vector3 startPoint;

		/// <summary>
		/// End point of the path.
		/// This is the closest point on the <see cref="endNode"/> to <see cref="originalEndPoint"/>
		/// </summary>
		public Vector3 endPoint;

		/// <summary>
		/// Determines if a search for an end node should be done.
		/// Set by different path types.
		/// Since: Added in 3.0.8.3
		/// </summary>
		protected virtual bool hasEndPoint {
			get {
				return true;
			}
		}

		public Int3 startIntPoint; /// <summary>< Start point in integer coordinates</summary>

		/// <summary>
		/// Calculate partial path if the target node cannot be reached.
		/// If the target node cannot be reached, the node which was closest (given by heuristic) will be chosen as target node
		/// and a partial path will be returned.
		/// This only works if a heuristic is used (which is the default).
		/// If a partial path is found, CompleteState is set to Partial.
		/// Note: It is not required by other path types to respect this setting
		///
		/// The <see cref="endNode"/> and <see cref="endPoint"/> will be modified and be set to the node which ends up being closest to the target.
		///
		/// Warning: Using this may make path calculations significantly slower if you have a big graph. The reason is that
		/// when the target node cannot be reached, the path must search through every single other node that it can reach in order
		/// to determine which one is closest. This may be expensive, and is why this option is disabled by default.
		/// </summary>
		public bool calculatePartial;

		/// <summary>
		/// Current best target for the partial path.
		/// This is the node with the lowest H score.
		/// </summary>
		protected PathNode partialBestTarget;

		/// <summary>Saved original costs for the end node. See: ResetCosts</summary>
		protected int[] endNodeCosts;

#if !ASTAR_NO_GRID_GRAPH
		/// <summary>Used in EndPointGridGraphSpecialCase</summary>
		GridNode gridSpecialCaseNode;
#endif

		/// <summary>@{ @name Constructors</summary>

		/// <summary>
		/// Default constructor.
		/// Do not use this. Instead use the static Construct method which can handle path pooling.
		/// </summary>
		public ABPath () {}

		/// <summary>
		/// Construct a path with a start and end point.
		/// The delegate will be called when the path has been calculated.
		/// Do not confuse it with the Seeker callback as they are sent at different times.
		/// If you are using a Seeker to start the path you can set callback to null.
		///
		/// Returns: The constructed path object
		/// </summary>
		public static ABPath Construct (Vector3 start, Vector3 end, OnPathDelegate callback = null) {
			var p = PathPool.GetPath<ABPath>();

			p.Setup(start, end, callback);
			return p;
		}

		protected void Setup (Vector3 start, Vector3 end, OnPathDelegate callbackDelegate) {
			callback = callbackDelegate;
			UpdateStartEnd(start, end);
		}

		/// <summary>
		/// Creates a fake path.
		/// Creates a path that looks almost exactly like it would if the pathfinding system had calculated it.
		///
		/// This is useful if you want your agents to follow some known path that cannot be calculated using the pathfinding system for some reason.
		///
		/// <code>
		/// var path = ABPath.FakePath(new List<Vector3> { new Vector3(1, 2, 3), new Vector3(4, 5, 6) });
		///
		/// ai.SetPath(path);
		/// </code>
		///
		/// You can use it to combine existing paths like this:
		///
		/// <code>
		/// var a = Vector3.zero;
		/// var b = new Vector3(1, 2, 3);
		/// var c = new Vector3(2, 3, 4);
		/// var path1 = ABPath.Construct(a, b);
		/// var path2 = ABPath.Construct(b, c);
		///
		/// AstarPath.StartPath(path1);
		/// AstarPath.StartPath(path2);
		/// path1.BlockUntilCalculated();
		/// path2.BlockUntilCalculated();
		///
		/// // Combine the paths
		/// // Note: Skip the first element in the second path as that will likely be the last element in the first path
		/// var newVectorPath = path1.vectorPath.Concat(path2.vectorPath.Skip(1)).ToList();
		/// var newNodePath = path1.path.Concat(path2.path.Skip(1)).ToList();
		/// var combinedPath = ABPath.FakePath(newVectorPath, newNodePath);
		/// </code>
		/// </summary>
		public static ABPath FakePath (List<Vector3> vectorPath, List<GraphNode> nodePath = null) {
			var path = PathPool.GetPath<ABPath>();

			for (int i = 0; i < vectorPath.Count; i++) path.vectorPath.Add(vectorPath[i]);

			path.completeState = PathCompleteState.Complete;
			((IPathInternals)path).AdvanceState(PathState.Returned);

			if (vectorPath.Count > 0) {
				path.UpdateStartEnd(vectorPath[0], vectorPath[vectorPath.Count - 1]);
			}

			if (nodePath != null) {
				for (int i = 0; i < nodePath.Count; i++) path.path.Add(nodePath[i]);
				if (nodePath.Count > 0) {
					path.startNode = nodePath[0];
					path.endNode = nodePath[nodePath.Count - 1];
				}
			}

			return path;
		}

		/// <summary>@}</summary>

		/// <summary>
		/// Sets the start and end points.
		/// Sets <see cref="originalStartPoint"/>, <see cref="originalEndPoint"/>, <see cref="startPoint"/>, <see cref="endPoint"/>, <see cref="startIntPoint"/> and <see cref="hTarget"/> (to end )
		/// </summary>
		protected void UpdateStartEnd (Vector3 start, Vector3 end) {
			originalStartPoint = start;
			originalEndPoint = end;

			startPoint = start;
			endPoint = end;

			startIntPoint = (Int3)start;
			hTarget = (Int3)end;
		}

		public override uint GetConnectionSpecialCost (GraphNode a, GraphNode b, uint currentCost) {
			if (startNode != null && endNode != null) {
				if (a == startNode) {
					return (uint)((startIntPoint - (b == endNode ? hTarget : b.position)).costMagnitude * (currentCost*1.0/(a.position-b.position).costMagnitude));
				}
				if (b == startNode) {
					return (uint)((startIntPoint - (a == endNode ? hTarget : a.position)).costMagnitude * (currentCost*1.0/(a.position-b.position).costMagnitude));
				}
				if (a == endNode) {
					return (uint)((hTarget - b.position).costMagnitude * (currentCost*1.0/(a.position-b.position).costMagnitude));
				}
				if (b == endNode) {
					return (uint)((hTarget - a.position).costMagnitude * (currentCost*1.0/(a.position-b.position).costMagnitude));
				}
			} else {
				// endNode is null, startNode should never be null for an ABPath
				if (a == startNode) {
					return (uint)((startIntPoint - b.position).costMagnitude * (currentCost*1.0/(a.position-b.position).costMagnitude));
				}
				if (b == startNode) {
					return (uint)((startIntPoint - a.position).costMagnitude * (currentCost*1.0/(a.position-b.position).costMagnitude));
				}
			}

			return currentCost;
		}

		/// <summary>
		/// Reset all values to their default values.
		/// All inheriting path types must implement this function, resetting ALL their variables to enable recycling of paths.
		/// Call this base function in inheriting types with base.Reset ();
		/// </summary>
		protected override void Reset () {
			base.Reset();

			startNode = null;
			endNode = null;
			originalStartPoint = Vector3.zero;
			originalEndPoint = Vector3.zero;
			startPoint = Vector3.zero;
			endPoint = Vector3.zero;
			calculatePartial = false;
			partialBestTarget = null;
			startIntPoint = new Int3();
			hTarget = new Int3();
			endNodeCosts = null;

#if !ASTAR_NO_GRID_GRAPH
			gridSpecialCaseNode = null;
#endif
		}

#if !ASTAR_NO_GRID_GRAPH
		/// <summary>Cached <see cref="Pathfinding.NNConstraint.None"/> to reduce allocations</summary>
		static readonly NNConstraint NNConstraintNone = NNConstraint.None;

		/// <summary>
		/// Applies a special case for grid nodes.
		///
		/// Assume the closest walkable node is a grid node.
		/// We will now apply a special case only for grid graphs.
		/// In tile based games, an obstacle often occupies a whole
		/// node. When a path is requested to the position of an obstacle
		/// (single unwalkable node) the closest walkable node will be
		/// one of the 8 nodes surrounding that unwalkable node
		/// but that node is not neccessarily the one that is most
		/// optimal to walk to so in this special case
		/// we mark all nodes around the unwalkable node as targets
		/// and when we search and find any one of them we simply exit
		/// and set that first node we found to be the 'real' end node
		/// because that will be the optimal node (this does not apply
		/// in general unless the heuristic is set to None, but
		/// for a single unwalkable node it does).
		/// This also applies if the nearest node cannot be traversed for
		/// some other reason like restricted tags.
		///
		/// Returns: True if the workaround was applied. If this happens the
		/// endPoint, endNode, hTarget and hTargetNode fields will be modified.
		///
		/// Image below shows paths when this special case is applied. The path goes from the white sphere to the orange box.
		/// [Open online documentation to see images]
		///
		/// Image below shows paths when this special case has been disabled
		/// [Open online documentation to see images]
		/// </summary>
		protected virtual bool EndPointGridGraphSpecialCase (GraphNode closestWalkableEndNode) {
			var gridNode = closestWalkableEndNode as GridNode;

			if (gridNode != null) {
				var gridGraph = GridNode.GetGridGraph(gridNode.GraphIndex);

				// Find the closest node, not neccessarily walkable
				var endNNInfo2 = AstarPath.active.GetNearest(originalEndPoint, NNConstraintNone);
				var gridNode2 = endNNInfo2.node as GridNode;

				if (gridNode != gridNode2 && gridNode2 != null && gridNode.GraphIndex == gridNode2.GraphIndex) {
					// Calculate the coordinates of the nodes
					var x1 = gridNode.NodeInGridIndex % gridGraph.width;
					var z1 = gridNode.NodeInGridIndex / gridGraph.width;

					var x2 = gridNode2.NodeInGridIndex % gridGraph.width;
					var z2 = gridNode2.NodeInGridIndex / gridGraph.width;

					bool wasClose = false;
					switch (gridGraph.neighbours) {
					case NumNeighbours.Four:
						if ((x1 == x2 && System.Math.Abs(z1-z2) == 1) || (z1 == z2 && System.Math.Abs(x1-x2) == 1)) {
							// If 'O' is gridNode2, then gridNode is one of the nodes marked with an 'x'
							//    x
							//  x O x
							//    x
							wasClose = true;
						}
						break;
					case NumNeighbours.Eight:
						if (System.Math.Abs(x1-x2) <= 1 && System.Math.Abs(z1-z2) <= 1) {
							// If 'O' is gridNode2, then gridNode is one of the nodes marked with an 'x'
							//  x x x
							//  x O x
							//  x x x
							wasClose = true;
						}
						break;
					case NumNeighbours.Six:
						// Hexagon graph
						for (int i = 0; i < 6; i++) {
							var nx = x2 + gridGraph.neighbourXOffsets[GridGraph.hexagonNeighbourIndices[i]];
							var nz = z2 + gridGraph.neighbourZOffsets[GridGraph.hexagonNeighbourIndices[i]];
							if (x1 == nx && z1 == nz) {
								// If 'O' is gridNode2, then gridNode is one of the nodes marked with an 'x'
								//    x x
								//  x O x
								//  x x
								wasClose = true;
								break;
							}
						}
						break;
					default:
						// Should not happen unless NumNeighbours is modified in the future
						throw new System.Exception("Unhandled NumNeighbours");
					}

					if (wasClose) {
						// We now need to find all nodes marked with an x to be able to mark them as targets
						SetFlagOnSurroundingGridNodes(gridNode2, 1, true);

						// Note, other methods assume hTarget is (Int3)endPoint
						endPoint = (Vector3)gridNode2.position;
						hTarget = gridNode2.position;
						endNode = gridNode2;

						// hTargetNode is used for heuristic optimizations
						// (also known as euclidean embedding).
						// Even though the endNode is not walkable
						// we can use it for better heuristics since
						// there is a workaround added (EuclideanEmbedding.ApplyGridGraphEndpointSpecialCase)
						// which is there to support this case.
						hTargetNode = endNode;

						// We need to save this node
						// so that we can reset flag1 on all nodes later
						gridSpecialCaseNode = gridNode2;
						return true;
					}
				}
			}

			return false;
		}

		/// <summary>Helper method to set PathNode.flag1 to a specific value for all nodes adjacent to a grid node</summary>
		void SetFlagOnSurroundingGridNodes (GridNode gridNode, int flag, bool flagState) {
			// Loop through all adjacent grid nodes
			var gridGraph = GridNode.GetGridGraph(gridNode.GraphIndex);

			// Number of neighbours as an int
			int mxnum = gridGraph.neighbours == NumNeighbours.Four ? 4 : (gridGraph.neighbours == NumNeighbours.Eight ? 8 : 6);

			// Calculate the coordinates of the node
			var x = gridNode.NodeInGridIndex % gridGraph.width;
			var z = gridNode.NodeInGridIndex / gridGraph.width;

			if (flag != 1 && flag != 2)
				throw new System.ArgumentOutOfRangeException("flag");

			for (int i = 0; i < mxnum; i++) {
				int nx, nz;
				if (gridGraph.neighbours == NumNeighbours.Six) {
					// Hexagon graph
					nx = x + gridGraph.neighbourXOffsets[GridGraph.hexagonNeighbourIndices[i]];
					nz = z + gridGraph.neighbourZOffsets[GridGraph.hexagonNeighbourIndices[i]];
				} else {
					nx = x + gridGraph.neighbourXOffsets[i];
					nz = z + gridGraph.neighbourZOffsets[i];
				}

				// Check if the position is still inside the grid
				if (nx >= 0 && nz >= 0 && nx < gridGraph.width && nz < gridGraph.depth) {
					var adjacentNode = gridGraph.nodes[nz*gridGraph.width + nx];
					var pathNode = pathHandler.GetPathNode(adjacentNode);
					if (flag == 1) pathNode.flag1 = flagState;
					else pathNode.flag2 = flagState;
				}
			}
		}
#endif

		/// <summary>Prepares the path. Searches for start and end nodes and does some simple checking if a path is at all possible</summary>
		protected override void Prepare () {
			AstarProfiler.StartProfile("Get Nearest");

			//Initialize the NNConstraint
			nnConstraint.tags = enabledTags;
			var startNNInfo  = AstarPath.active.GetNearest(startPoint, nnConstraint);

			//Tell the NNConstraint which node was found as the start node if it is a PathNNConstraint and not a normal NNConstraint
			var pathNNConstraint = nnConstraint as PathNNConstraint;
			if (pathNNConstraint != null) {
				pathNNConstraint.SetStart(startNNInfo.node);
			}

			startPoint = startNNInfo.position;

			startIntPoint = (Int3)startPoint;
			startNode = startNNInfo.node;

			if (startNode == null) {
				FailWithError("Couldn't find a node close to the start point");
				return;
			}

			if (!CanTraverse(startNode)) {
				FailWithError("The node closest to the start point could not be traversed");
				return;
			}

			// If it is declared that this path type has an end point
			// Some path types might want to use most of the ABPath code, but will not have an explicit end point at this stage
			if (hasEndPoint) {
				var endNNInfo = AstarPath.active.GetNearest(endPoint, nnConstraint);
				endPoint = endNNInfo.position;
				endNode = endNNInfo.node;

				if (endNode == null) {
					FailWithError("Couldn't find a node close to the end point");
					return;
				}

				// This should not trigger unless the user has modified the NNConstraint
				if (!CanTraverse(endNode)) {
					FailWithError("The node closest to the end point could not be traversed");
					return;
				}

				// This should not trigger unless the user has modified the NNConstraint
				if (startNode.Area != endNode.Area) {
					FailWithError("There is no valid path to the target");
					return;
				}

#if !ASTAR_NO_GRID_GRAPH
				// Potentially we want to special case grid graphs a bit
				// to better support some kinds of games
				// If this returns true it will overwrite the
				// endNode, endPoint, hTarget and hTargetNode fields
				if (!EndPointGridGraphSpecialCase(endNNInfo.node))
#endif
				{
					// Note, other methods assume hTarget is (Int3)endPoint
					hTarget = (Int3)endPoint;
					hTargetNode = endNode;

					// Mark end node with flag1 to mark it as a target point
					pathHandler.GetPathNode(endNode).flag1 = true;
				}
			}

			AstarProfiler.EndProfile();
		}

		/// <summary>
		/// Checks if the start node is the target and complete the path if that is the case.
		/// This is necessary so that subclasses (e.g XPath) can override this behaviour.
		///
		/// If the start node is a valid target point, this method should set CompleteState to Complete
		/// and trace the path.
		/// </summary>
		protected virtual void CompletePathIfStartIsValidTarget () {
			// flag1 specifies if a node is a target node for the path
			if (hasEndPoint && pathHandler.GetPathNode(startNode).flag1) {
				CompleteWith(startNode);
				Trace(pathHandler.GetPathNode(startNode));
			}
		}

		protected override void Initialize () {
			// Mark nodes to enable special connection costs for start and end nodes
			// See GetConnectionSpecialCost
			if (startNode != null) pathHandler.GetPathNode(startNode).flag2 = true;
			if (endNode != null) pathHandler.GetPathNode(endNode).flag2 = true;

			// Zero out the properties on the start node
			PathNode startRNode = pathHandler.GetPathNode(startNode);
			startRNode.node = startNode;
			startRNode.pathID = pathHandler.PathID;
			startRNode.parent = null;
			startRNode.cost = 0;
			startRNode.G = GetTraversalCost(startNode);
			startRNode.H = CalculateHScore(startNode);

			// Check if the start node is the target and complete the path if that is the case
			CompletePathIfStartIsValidTarget();
			if (CompleteState == PathCompleteState.Complete) return;

			// Open the start node and puts its neighbours in the open list
			startNode.Open(this, startRNode, pathHandler);

			searchedNodes++;

			partialBestTarget = startRNode;

			// Any nodes left to search?
			if (pathHandler.heap.isEmpty) {
				if (calculatePartial) {
					CompletePartial(partialBestTarget);
				} else {
					FailWithError("The start node either had no neighbours, or no neighbours that the path could traverse");
				}
				return;
			}

			// Pop the first node off the open list
			currentR = pathHandler.heap.Remove();
		}

		protected override void Cleanup () {
			// TODO: Set flag1 = false as well?
			if (startNode != null) {
				var pathStartNode = pathHandler.GetPathNode(startNode);
				pathStartNode.flag1 = false;
				pathStartNode.flag2 = false;
			}

			if (endNode != null) {
				var pathEndNode = pathHandler.GetPathNode(endNode);
				pathEndNode.flag1 = false;
				pathEndNode.flag2 = false;
			}

#if !ASTAR_NO_GRID_GRAPH
			// Set flag1 and flag2 to false on all nodes we set it to true on
			// at the start of the path call. Otherwise this state
			// will leak to other path calculations and cause all
			// kinds of havoc.
			// flag2 is also set because the end node could have changed
			// and thus the flag2 which is set to false above might not set
			// it on the correct node
			if (gridSpecialCaseNode != null) {
				var pathNode = pathHandler.GetPathNode(gridSpecialCaseNode);
				pathNode.flag1 = false;
				pathNode.flag2 = false;
				SetFlagOnSurroundingGridNodes(gridSpecialCaseNode, 1, false);
				SetFlagOnSurroundingGridNodes(gridSpecialCaseNode, 2, false);
			}
#endif
		}

		void CompletePartial (PathNode node) {
			CompleteState = PathCompleteState.Partial;
			endNode = node.node;
			endPoint = endNode.ClosestPointOnNode(originalEndPoint);
			Trace(node);
		}

		/// <summary>
		/// Completes the path using the specified target node.
		/// This method assumes that the node is a target node of the path
		/// not just any random node.
		/// </summary>
		void CompleteWith (GraphNode node) {
#if !ASTAR_NO_GRID_GRAPH
			if (endNode == node) {
				// Common case, no grid graph special case has been applied
				// Nothing to do
			} else {
				// See EndPointGridGraphSpecialCase()
				var gridNode = node as GridNode;
				if (gridNode == null) {
					throw new System.Exception("Some path is not cleaning up the flag1 field. This is a bug.");
				}

				// The grid graph special case has been applied
				// The closest point on the node is not yet known
				// so we need to calculate it
				endPoint = gridNode.ClosestPointOnNode(originalEndPoint);
				// This is now our end node
				// We didn't know it before, but apparently it was optimal
				// to move to this node
				endNode = node;
			}
#else
			// This should always be true unless
			// the grid graph special case has been applied
			// which can only happen if grid graphs have not
			// been stripped out with ASTAR_NO_GRID_GRAPH
			node.MustBeEqual(endNode);
#endif
			// Mark the path as completed
			CompleteState = PathCompleteState.Complete;
		}

		/// <summary>
		/// Calculates the path until completed or until the time has passed targetTick.
		/// Usually a check is only done every 500 nodes if the time has passed targetTick.
		/// Time/Ticks are got from System.DateTime.UtcNow.Ticks.
		///
		/// Basic outline of what the function does for the standard path (Pathfinding.ABPath).
		/// <code>
		/// while the end has not been found and no error has occurred
		/// check if we have reached the end
		/// if so, exit and return the path
		///
		/// open the current node, i.e loop through its neighbours, mark them as visited and put them on a heap
		///
		/// check if there are still nodes left to process (or have we searched the whole graph)
		/// if there are none, flag error and exit
		///
		/// pop the next node of the heap and set it as current
		///
		/// check if the function has exceeded the time limit
		/// if so, return and wait for the function to get called again
		/// </code>
		/// </summary>
		protected override void CalculateStep (long targetTick) {
			int counter = 0;

			// Continue to search as long as we haven't encountered an error and we haven't found the target
			while (CompleteState == PathCompleteState.NotCalculated) {
				searchedNodes++;

				// Close the current node, if the current node is the target node then the path is finished
				if (currentR.flag1) {
					// We found a target point
					// Mark that node as the end point
					CompleteWith(currentR.node);
					break;
				}

				if (currentR.H < partialBestTarget.H) {
					partialBestTarget = currentR;
				}

				AstarProfiler.StartFastProfile(4);

				// Loop through all walkable neighbours of the node and add them to the open list.
				currentR.node.Open(this, currentR, pathHandler);

				AstarProfiler.EndFastProfile(4);

				// Any nodes left to search?
				if (pathHandler.heap.isEmpty) {
					if (calculatePartial && partialBestTarget != null) {
						CompletePartial(partialBestTarget);
					} else {
						FailWithError("Searched all reachable nodes, but could not find target. This can happen if you have nodes with a different tag blocking the way to the goal. You can enable path.calculatePartial to handle that case workaround (though this comes with a performance cost).");
					}
					return;
				}

				// Select the node with the lowest F score and remove it from the open list
				AstarProfiler.StartFastProfile(7);
				currentR = pathHandler.heap.Remove();
				AstarProfiler.EndFastProfile(7);

				// Check for time every 500 nodes, roughly every 0.5 ms usually
				if (counter > 500) {
					// Have we exceded the maxFrameTime, if so we should wait one frame before continuing the search since we don't want the game to lag
					if (System.DateTime.UtcNow.Ticks >= targetTick) {
						// Return instead of yield'ing, a separate function handles the yield (CalculatePaths)
						return;
					}
					counter = 0;

					// Mostly for development
					if (searchedNodes > 1000000) {
						throw new System.Exception("Probable infinite loop. Over 1,000,000 nodes searched");
					}
				}

				counter++;
			}

			AstarProfiler.StartProfile("Trace");

			if (CompleteState == PathCompleteState.Complete) {
				Trace(currentR);
			} else if (calculatePartial && partialBestTarget != null) {
				CompletePartial(partialBestTarget);
			}

			AstarProfiler.EndProfile();
		}

		/// <summary>Returns a debug string for this path.</summary>
		protected override string DebugString (PathLog logMode) {
			if (logMode == PathLog.None || (!error && logMode == PathLog.OnlyErrors)) {
				return "";
			}

			var text = new System.Text.StringBuilder();

			DebugStringPrefix(logMode, text);

			if (!error && logMode == PathLog.Heavy) {
				if (hasEndPoint && endNode != null) {
					PathNode nodeR = pathHandler.GetPathNode(endNode);
					text.Append("\nEnd Node\n	G: ");
					text.Append(nodeR.G);
					text.Append("\n	H: ");
					text.Append(nodeR.H);
					text.Append("\n	F: ");
					text.Append(nodeR.F);
					text.Append("\n	Point: ");
					text.Append(((Vector3)endPoint).ToString());
					text.Append("\n	Graph: ");
					text.Append(endNode.GraphIndex);
				}

				text.Append("\nStart Node");
				text.Append("\n	Point: ");
				text.Append(((Vector3)startPoint).ToString());
				text.Append("\n	Graph: ");
				if (startNode != null) text.Append(startNode.GraphIndex);
				else text.Append("< null startNode >");
			}

			DebugStringSuffix(logMode, text);

			return text.ToString();
		}

		/// <summary>\cond INTERNAL</summary>
		/// <summary>
		/// Returns in which direction to move from a point on the path.
		/// A simple and quite slow (well, compared to more optimized algorithms) algorithm first finds the closest path segment (from <see cref="vectorPath)"/> and then returns
		/// the direction to the next point from there. The direction is not normalized.
		/// Returns: Direction to move from a point, returns Vector3.zero if <see cref="vectorPath"/> is null or has a length of 0
		/// Deprecated:
		/// </summary>
		[System.Obsolete()]
		public Vector3 GetMovementVector (Vector3 point) {
			if (vectorPath == null || vectorPath.Count == 0) {
				return Vector3.zero;
			}

			if (vectorPath.Count == 1) {
				return vectorPath[0]-point;
			}

			float minDist = float.PositiveInfinity;//Mathf.Infinity;
			int minSegment = 0;

			for (int i = 0; i < vectorPath.Count-1; i++) {
				Vector3 closest = VectorMath.ClosestPointOnSegment(vectorPath[i], vectorPath[i+1], point);
				float dist = (closest-point).sqrMagnitude;
				if (dist < minDist) {
					minDist = dist;
					minSegment = i;
				}
			}

			return vectorPath[minSegment+1]-point;
		}

		/// <summary>\endcond</summary>
	}
}