ET/Unity/Assets/Plugins/AstarPathfindingProject/Core/AI/Seeker.cs

using UnityEngine;
using System.Collections.Generic;
using UnityEngine.Profiling;

namespace Pathfinding {
	/// <summary>
	/// Handles path calls for a single unit.
	///
	/// This is a component which is meant to be attached to a single unit (AI, Robot, Player, whatever) to handle its pathfinding calls.
	/// It also handles post-processing of paths using modifiers.
	///
	/// [Open online documentation to see images]
	///
	/// See: calling-pathfinding (view in online documentation for working links)
	/// See: modifiers (view in online documentation for working links)
	/// </summary>
	[AddComponentMenu("Pathfinding/Seeker")]
	[HelpURL("http://arongranberg.com/astar/documentation/stable/class_pathfinding_1_1_seeker.php")]
	public class Seeker : VersionedMonoBehaviour {
		/// <summary>
		/// Enables drawing of the last calculated path using Gizmos.
		/// The path will show up in green.
		///
		/// See: OnDrawGizmos
		/// </summary>
		public bool drawGizmos = true;

		/// <summary>
		/// Enables drawing of the non-postprocessed path using Gizmos.
		/// The path will show up in orange.
		///
		/// Requires that <see cref="drawGizmos"/> is true.
		///
		/// This will show the path before any post processing such as smoothing is applied.
		///
		/// See: drawGizmos
		/// See: OnDrawGizmos
		/// </summary>
		public bool detailedGizmos;

		/// <summary>Path modifier which tweaks the start and end points of a path</summary>
		[HideInInspector]
		public StartEndModifier startEndModifier = new StartEndModifier();

		/// <summary>
		/// The tags which the Seeker can traverse.
		///
		/// Note: This field is a bitmask.
		/// See: bitmasks (view in online documentation for working links)
		/// </summary>
		[HideInInspector]
		public int traversableTags = -1;

		/// <summary>
		/// Penalties for each tag.
		/// Tag 0 which is the default tag, will have added a penalty of tagPenalties[0].
		/// These should only be positive values since the A* algorithm cannot handle negative penalties.
		///
		/// Note: This array should always have a length of 32 otherwise the system will ignore it.
		///
		/// See: Pathfinding.Path.tagPenalties
		/// </summary>
		[HideInInspector]
		public int[] tagPenalties = new int[32];

		/// <summary>
		/// Graphs that this Seeker can use.
		/// This field determines which graphs will be considered when searching for the start and end nodes of a path.
		/// It is useful in numerous situations, for example if you want to make one graph for small units and one graph for large units.
		///
		/// This is a bitmask so if you for example want to make the agent only use graph index 3 then you can set this to:
		/// <code> seeker.graphMask = 1 << 3; </code>
		///
		/// See: bitmasks (view in online documentation for working links)
		///
		/// Note that this field only stores which graph indices that are allowed. This means that if the graphs change their ordering
		/// then this mask may no longer be correct.
		///
		/// If you know the name of the graph you can use the <see cref="Pathfinding.GraphMask.FromGraphName"/> method:
		/// <code>
		/// GraphMask mask1 = GraphMask.FromGraphName("My Grid Graph");
		/// GraphMask mask2 = GraphMask.FromGraphName("My Other Grid Graph");
		///
		/// NNConstraint nn = NNConstraint.Default;
		///
		/// nn.graphMask = mask1 | mask2;
		///
		/// // Find the node closest to somePoint which is either in 'My Grid Graph' OR in 'My Other Grid Graph'
		/// var info = AstarPath.active.GetNearest(somePoint, nn);
		/// </code>
		///
		/// Some overloads of the <see cref="StartPath"/> methods take a graphMask parameter. If those overloads are used then they
		/// will override the graph mask for that path request.
		///
		/// [Open online documentation to see images]
		///
		/// See: multiple-agent-types (view in online documentation for working links)
		/// </summary>
		[HideInInspector]
		public GraphMask graphMask = GraphMask.everything;

		/// <summary>Used for serialization backwards compatibility</summary>
		[UnityEngine.Serialization.FormerlySerializedAs("graphMask")]
		int graphMaskCompatibility = -1;

		/// <summary>
		/// Callback for when a path is completed.
		/// Movement scripts should register to this delegate.
		/// A temporary callback can also be set when calling StartPath, but that delegate will only be called for that path
		/// </summary>
		public OnPathDelegate pathCallback;

		/// <summary>Called before pathfinding is started</summary>
		public OnPathDelegate preProcessPath;

		/// <summary>Called after a path has been calculated, right before modifiers are executed.</summary>
		public OnPathDelegate postProcessPath;

		/// <summary>Used for drawing gizmos</summary>
		[System.NonSerialized]
		List<Vector3> lastCompletedVectorPath;

		/// <summary>Used for drawing gizmos</summary>
		[System.NonSerialized]
		List<GraphNode> lastCompletedNodePath;

		/// <summary>The current path</summary>
		[System.NonSerialized]
		protected Path path;

		/// <summary>Previous path. Used to draw gizmos</summary>
		[System.NonSerialized]
		private Path prevPath;

		/// <summary>Cached delegate to avoid allocating one every time a path is started</summary>
		private readonly OnPathDelegate onPathDelegate;
		/// <summary>Cached delegate to avoid allocating one every time a path is started</summary>
		private readonly OnPathDelegate onPartialPathDelegate;

		/// <summary>Temporary callback only called for the current path. This value is set by the StartPath functions</summary>
		private OnPathDelegate tmpPathCallback;

		/// <summary>The path ID of the last path queried</summary>
		protected uint lastPathID;

		/// <summary>Internal list of all modifiers</summary>
		readonly List<IPathModifier> modifiers = new List<IPathModifier>();

		public enum ModifierPass {
			PreProcess,
			// An obsolete item occupied index 1 previously
			PostProcess = 2,
		}

		public Seeker () {
			onPathDelegate = OnPathComplete;
			onPartialPathDelegate = OnPartialPathComplete;
		}

		/// <summary>Initializes a few variables</summary>
		protected override void Awake () {
			base.Awake();
			startEndModifier.Awake(this);
		}

		/// <summary>
		/// Path that is currently being calculated or was last calculated.
		/// You should rarely have to use this. Instead get the path when the path callback is called.
		///
		/// See: pathCallback
		/// </summary>
		public Path GetCurrentPath () {
			return path;
		}

		/// <summary>
		/// Stop calculating the current path request.
		/// If this Seeker is currently calculating a path it will be canceled.
		/// The callback (usually to a method named OnPathComplete) will soon be called
		/// with a path that has the 'error' field set to true.
		///
		/// This does not stop the character from moving, it just aborts
		/// the path calculation.
		/// </summary>
		/// <param name="pool">If true then the path will be pooled when the pathfinding system is done with it.</param>
		public void CancelCurrentPathRequest (bool pool = true) {
			if (!IsDone()) {
				path.FailWithError("Canceled by script (Seeker.CancelCurrentPathRequest)");
				if (pool) {
					// Make sure the path has had its reference count incremented and decremented once.
					// If this is not done the system will think no pooling is used at all and will not pool the path.
					// The particular object that is used as the parameter (in this case 'path') doesn't matter at all
					// it just has to be *some* object.
					path.Claim(path);
					path.Release(path);
				}
			}
		}

		/// <summary>
		/// Cleans up some variables.
		/// Releases any eventually claimed paths.
		/// Calls OnDestroy on the <see cref="startEndModifier"/>.
		///
		/// See: <see cref="ReleaseClaimedPath"/>
		/// See: <see cref="startEndModifier"/>
		/// </summary>
		public void OnDestroy () {
			ReleaseClaimedPath();
			startEndModifier.OnDestroy(this);
		}

		/// <summary>
		/// Releases the path used for gizmos (if any).
		/// The seeker keeps the latest path claimed so it can draw gizmos.
		/// In some cases this might not be desireable and you want it released.
		/// In that case, you can call this method to release it (not that path gizmos will then not be drawn).
		///
		/// If you didn't understand anything from the description above, you probably don't need to use this method.
		///
		/// See: pooling (view in online documentation for working links)
		/// </summary>
		void ReleaseClaimedPath () {
			if (prevPath != null) {
				prevPath.Release(this, true);
				prevPath = null;
			}
		}

		/// <summary>Called by modifiers to register themselves</summary>
		public void RegisterModifier (IPathModifier modifier) {
			modifiers.Add(modifier);

			// Sort the modifiers based on their specified order
			modifiers.Sort((a, b) => a.Order.CompareTo(b.Order));
		}

		/// <summary>Called by modifiers when they are disabled or destroyed</summary>
		public void DeregisterModifier (IPathModifier modifier) {
			modifiers.Remove(modifier);
		}

		/// <summary>
		/// Post Processes the path.
		/// This will run any modifiers attached to this GameObject on the path.
		/// This is identical to calling RunModifiers(ModifierPass.PostProcess, path)
		/// See: RunModifiers
		/// Since: Added in 3.2
		/// </summary>
		public void PostProcess (Path path) {
			RunModifiers(ModifierPass.PostProcess, path);
		}

		/// <summary>Runs modifiers on a path</summary>
		public void RunModifiers (ModifierPass pass, Path path) {
			if (pass == ModifierPass.PreProcess) {
				if (preProcessPath != null) preProcessPath(path);

				for (int i = 0; i < modifiers.Count; i++) modifiers[i].PreProcess(path);
			} else if (pass == ModifierPass.PostProcess) {
				Profiler.BeginSample("Running Path Modifiers");
				// Call delegates if they exist
				if (postProcessPath != null) postProcessPath(path);

				// Loop through all modifiers and apply post processing
				for (int i = 0; i < modifiers.Count; i++) modifiers[i].Apply(path);
				Profiler.EndSample();
			}
		}

		/// <summary>
		/// Is the current path done calculating.
		/// Returns true if the current <see cref="path"/> has been returned or if the <see cref="path"/> is null.
		///
		/// Note: Do not confuse this with Pathfinding.Path.IsDone. They usually return the same value, but not always
		/// since the path might be completely calculated, but it has not yet been processed by the Seeker.
		///
		/// Since: Added in 3.0.8
		/// Version: Behaviour changed in 3.2
		/// </summary>
		public bool IsDone () {
			return path == null || path.PipelineState >= PathState.Returned;
		}

		/// <summary>
		/// Called when a path has completed.
		/// This should have been implemented as optional parameter values, but that didn't seem to work very well with delegates (the values weren't the default ones)
		/// See: OnPathComplete(Path,bool,bool)
		/// </summary>
		void OnPathComplete (Path path) {
			OnPathComplete(path, true, true);
		}

		/// <summary>
		/// Called when a path has completed.
		/// Will post process it and return it by calling <see cref="tmpPathCallback"/> and <see cref="pathCallback"/>
		/// </summary>
		void OnPathComplete (Path p, bool runModifiers, bool sendCallbacks) {
			if (p != null && p != path && sendCallbacks) {
				return;
			}

			if (this == null || p == null || p != path)
				return;

			if (!path.error && runModifiers) {
				// This will send the path for post processing to modifiers attached to this Seeker
				RunModifiers(ModifierPass.PostProcess, path);
			}

			if (sendCallbacks) {
				p.Claim(this);

				lastCompletedNodePath = p.path;
				lastCompletedVectorPath = p.vectorPath;

				// This will send the path to the callback (if any) specified when calling StartPath
				if (tmpPathCallback != null) {
					tmpPathCallback(p);
				}

				// This will send the path to any script which has registered to the callback
				if (pathCallback != null) {
					pathCallback(p);
				}

				// Note: it is important that #prevPath is kept alive (i.e. not pooled)
				// if we are drawing gizmos.
				// It is also important that #path is kept alive since it can be returned
				// from the GetCurrentPath method.
				// Since #path will be copied to #prevPath it is sufficient that #prevPath
				// is kept alive until it is replaced.

				// Recycle the previous path to reduce the load on the GC
				if (prevPath != null) {
					prevPath.Release(this, true);
				}

				prevPath = p;
			}
		}

		/// <summary>
		/// Called for each path in a MultiTargetPath.
		/// Only post processes the path, does not return it.
		/// </summary>
		void OnPartialPathComplete (Path p) {
			OnPathComplete(p, true, false);
		}

		/// <summary>Called once for a MultiTargetPath. Only returns the path, does not post process.</summary>
		void OnMultiPathComplete (Path p) {
			OnPathComplete(p, false, true);
		}

		/// <summary>
		/// Returns a new path instance.
		/// The path will be taken from the path pool if path recycling is turned on.
		/// This path can be sent to <see cref="StartPath(Path,OnPathDelegate,int)"/> with no change, but if no change is required <see cref="StartPath(Vector3,Vector3,OnPathDelegate)"/> does just that.
		/// <code>
		/// var seeker = GetComponent<Seeker>();
		/// Path p = seeker.GetNewPath (transform.position, transform.position+transform.forward*100);
		/// // Disable heuristics on just this path for example
		/// p.heuristic = Heuristic.None;
		/// seeker.StartPath (p, OnPathComplete);
		/// </code>
		/// Deprecated: Use ABPath.Construct(start, end, null) instead.
		/// </summary>
		[System.Obsolete("Use ABPath.Construct(start, end, null) instead")]
		public ABPath GetNewPath (Vector3 start, Vector3 end) {
			// Construct a path with start and end points
			return ABPath.Construct(start, end, null);
		}

		/// <summary>
		/// Call this function to start calculating a path.
		/// Since this method does not take a callback parameter, you should set the <see cref="pathCallback"/> field before calling this method.
		/// </summary>
		/// <param name="start">The start point of the path</param>
		/// <param name="end">The end point of the path</param>
		public Path StartPath (Vector3 start, Vector3 end) {
			return StartPath(start, end, null);
		}

		/// <summary>
		/// Call this function to start calculating a path.
		///
		/// The callback will be called when the path has been calculated (which may be several frames into the future).
		/// Callback will not be called if the path is canceled (e.g when a new path is requested before the previous one has completed)
		/// </summary>
		/// <param name="start">The start point of the path</param>
		/// <param name="end">The end point of the path</param>
		/// <param name="callback">The function to call when the path has been calculated</param>
		public Path StartPath (Vector3 start, Vector3 end, OnPathDelegate callback) {
			return StartPath(ABPath.Construct(start, end, null), callback);
		}

		/// <summary>
		/// Call this function to start calculating a path.
		///
		/// The callback will be called when the path has been calculated (which may be several frames into the future).
		/// Callback will not be called if the path is canceled (e.g when a new path is requested before the previous one has completed)
		/// </summary>
		/// <param name="start">The start point of the path</param>
		/// <param name="end">The end point of the path</param>
		/// <param name="callback">The function to call when the path has been calculated</param>
		/// <param name="graphMask">Mask used to specify which graphs should be searched for close nodes. See #Pathfinding.NNConstraint.graphMask. This will override #graphMask for this path request.</param>
		public Path StartPath (Vector3 start, Vector3 end, OnPathDelegate callback, GraphMask graphMask) {
			return StartPath(ABPath.Construct(start, end, null), callback, graphMask);
		}

		/// <summary>
		/// Call this function to start calculating a path.
		///
		/// The callback will be called when the path has been calculated (which may be several frames into the future).
		/// The callback will not be called if a new path request is started before this path request has been calculated.
		///
		/// Version: Since 3.8.3 this method works properly if a MultiTargetPath is used.
		/// It now behaves identically to the StartMultiTargetPath(MultiTargetPath) method.
		///
		/// Version: Since 4.1.x this method will no longer overwrite the graphMask on the path unless it is explicitly passed as a parameter (see other overloads of this method).
		/// </summary>
		/// <param name="p">The path to start calculating</param>
		/// <param name="callback">The function to call when the path has been calculated</param>
		public Path StartPath (Path p, OnPathDelegate callback = null) {
			// Set the graph mask only if the user has not changed it from the default value.
			// This is not perfect as the user may have wanted it to be precisely -1
			// however it is the best detection that I can do.
			// The non-default check is primarily for compatibility reasons to avoid breaking peoples existing code.
			// The StartPath overloads with an explicit graphMask field should be used instead to set the graphMask.
			if (p.nnConstraint.graphMask == -1) p.nnConstraint.graphMask = graphMask;
			StartPathInternal(p, callback);
			return p;
		}

		/// <summary>
		/// Call this function to start calculating a path.
		///
		/// The callback will be called when the path has been calculated (which may be several frames into the future).
		/// The callback will not be called if a new path request is started before this path request has been calculated.
		///
		/// Version: Since 3.8.3 this method works properly if a MultiTargetPath is used.
		/// It now behaves identically to the StartMultiTargetPath(MultiTargetPath) method.
		/// </summary>
		/// <param name="p">The path to start calculating</param>
		/// <param name="callback">The function to call when the path has been calculated</param>
		/// <param name="graphMask">Mask used to specify which graphs should be searched for close nodes. See #Pathfinding.GraphMask. This will override #graphMask for this path request.</param>
		public Path StartPath (Path p, OnPathDelegate callback, GraphMask graphMask) {
			p.nnConstraint.graphMask = graphMask;
			StartPathInternal(p, callback);
			return p;
		}

		/// <summary>Internal method to start a path and mark it as the currently active path</summary>
		void StartPathInternal (Path p, OnPathDelegate callback) {
			var mtp = p as MultiTargetPath;
			if (mtp != null) {
				// TODO: Allocation, cache
				var callbacks = new OnPathDelegate[mtp.targetPoints.Length];

				for (int i = 0; i < callbacks.Length; i++) {
					callbacks[i] = onPartialPathDelegate;
				}

				mtp.callbacks = callbacks;
				p.callback += OnMultiPathComplete;
			} else {
				p.callback += onPathDelegate;
			}

			p.enabledTags = traversableTags;
			p.tagPenalties = tagPenalties;

			// Cancel a previously requested path is it has not been processed yet and also make sure that it has not been recycled and used somewhere else
			if (path != null && path.PipelineState <= PathState.Processing && path.CompleteState != PathCompleteState.Error && lastPathID == path.pathID) {
				path.FailWithError("Canceled path because a new one was requested.\n"+
					"This happens when a new path is requested from the seeker when one was already being calculated.\n" +
					"For example if a unit got a new order, you might request a new path directly instead of waiting for the now" +
					" invalid path to be calculated. Which is probably what you want.\n" +
					"If you are getting this a lot, you might want to consider how you are scheduling path requests.");
				// No callback will be sent for the canceled path
			}

			// Set p as the active path
			path = p;
			tmpPathCallback = callback;

			// Save the path id so we can make sure that if we cancel a path (see above) it should not have been recycled yet.
			lastPathID = path.pathID;

			// Pre process the path
			RunModifiers(ModifierPass.PreProcess, path);

			// Send the request to the pathfinder
			AstarPath.StartPath(path);
		}

		/// <summary>
		/// Starts a Multi Target Path from one start point to multiple end points.
		/// A Multi Target Path will search for all the end points in one search and will return all paths if pathsForAll is true, or only the shortest one if pathsForAll is false.
		///
		/// callback and <see cref="pathCallback"/> will be called when the path has completed. Callback will not be called if the path is canceled (e.g when a new path is requested before the previous one has completed)
		///
		/// See: Pathfinding.MultiTargetPath
		/// See: MultiTargetPathExample.cs (view in online documentation for working links) "Example of how to use multi-target-paths"
		/// </summary>
		/// <param name="start">The start point of the path</param>
		/// <param name="endPoints">The end points of the path</param>
		/// <param name="pathsForAll">Indicates whether or not a path to all end points should be searched for or only to the closest one</param>
		/// <param name="callback">The function to call when the path has been calculated</param>
		/// <param name="graphMask">Mask used to specify which graphs should be searched for close nodes. See Pathfinding.NNConstraint.graphMask.</param>
		public MultiTargetPath StartMultiTargetPath (Vector3 start, Vector3[] endPoints, bool pathsForAll, OnPathDelegate callback = null, int graphMask = -1) {
			MultiTargetPath p = MultiTargetPath.Construct(start, endPoints, null, null);

			p.pathsForAll = pathsForAll;
			StartPath(p, callback, graphMask);
			return p;
		}

		/// <summary>
		/// Starts a Multi Target Path from multiple start points to a single target point.
		/// A Multi Target Path will search from all start points to the target point in one search and will return all paths if pathsForAll is true, or only the shortest one if pathsForAll is false.
		///
		/// callback and <see cref="pathCallback"/> will be called when the path has completed. Callback will not be called if the path is canceled (e.g when a new path is requested before the previous one has completed)
		///
		/// See: Pathfinding.MultiTargetPath
		/// See: MultiTargetPathExample.cs (view in online documentation for working links) "Example of how to use multi-target-paths"
		/// </summary>
		/// <param name="startPoints">The start points of the path</param>
		/// <param name="end">The end point of the path</param>
		/// <param name="pathsForAll">Indicates whether or not a path from all start points should be searched for or only to the closest one</param>
		/// <param name="callback">The function to call when the path has been calculated</param>
		/// <param name="graphMask">Mask used to specify which graphs should be searched for close nodes. See Pathfinding.NNConstraint.graphMask.</param>
		public MultiTargetPath StartMultiTargetPath (Vector3[] startPoints, Vector3 end, bool pathsForAll, OnPathDelegate callback = null, int graphMask = -1) {
			MultiTargetPath p = MultiTargetPath.Construct(startPoints, end, null, null);

			p.pathsForAll = pathsForAll;
			StartPath(p, callback, graphMask);
			return p;
		}

		/// <summary>
		/// Starts a Multi Target Path.
		/// Takes a MultiTargetPath and wires everything up for it to send callbacks to the seeker for post-processing.
		///
		/// callback and <see cref="pathCallback"/> will be called when the path has completed. Callback will not be called if the path is canceled (e.g when a new path is requested before the previous one has completed)
		///
		/// See: Pathfinding.MultiTargetPath
		/// See: MultiTargetPathExample.cs (view in online documentation for working links) "Example of how to use multi-target-paths"
		///
		/// Version: Since 3.8.3 calling this method behaves identically to calling StartPath with a MultiTargetPath.
		/// Version: Since 3.8.3 this method also sets enabledTags and tagPenalties on the path object.
		///
		/// Deprecated: You can use StartPath instead of this method now. It will behave identically.
		/// </summary>
		/// <param name="p">The path to start calculating</param>
		/// <param name="callback">The function to call when the path has been calculated</param>
		/// <param name="graphMask">Mask used to specify which graphs should be searched for close nodes. See Pathfinding.NNConstraint.graphMask.</param>
		[System.Obsolete("You can use StartPath instead of this method now. It will behave identically.")]
		public MultiTargetPath StartMultiTargetPath (MultiTargetPath p, OnPathDelegate callback = null, int graphMask = -1) {
			StartPath(p, callback, graphMask);
			return p;
		}

		/// <summary>Draws gizmos for the Seeker</summary>
		public void OnDrawGizmos () {
			if (lastCompletedNodePath == null || !drawGizmos) {
				return;
			}

			if (detailedGizmos) {
				Gizmos.color = new Color(0.7F, 0.5F, 0.1F, 0.5F);

				if (lastCompletedNodePath != null) {
					for (int i = 0; i < lastCompletedNodePath.Count-1; i++) {
						Gizmos.DrawLine((Vector3)lastCompletedNodePath[i].position, (Vector3)lastCompletedNodePath[i+1].position);
					}
				}
			}

			Gizmos.color = new Color(0, 1F, 0, 1F);

			if (lastCompletedVectorPath != null) {
				for (int i = 0; i < lastCompletedVectorPath.Count-1; i++) {
					Gizmos.DrawLine(lastCompletedVectorPath[i], lastCompletedVectorPath[i+1]);
				}
			}
		}

		protected override int OnUpgradeSerializedData (int version, bool unityThread) {
			if (graphMaskCompatibility != -1) {
				Debug.Log("Loaded " + graphMaskCompatibility + " " + graphMask.value);
				graphMask = graphMaskCompatibility;
				graphMaskCompatibility = -1;
			}
			return base.OnUpgradeSerializedData(version, unityThread);
		}
	}
}