A* Pathfinding Project
3.6.1
The A* Pathfinding Project for Unity 3D
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Basic path, finds the shortest path from A to B. More...
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 from A to B.
Many other path types inherit from this type.
Public Member Functions | |
ABPath (Vector3 start, Vector3 end, OnPathDelegate callbackDelegate) | |
Create a new path with a start and end point. | |
override void | CalculateStep (long targetTick) |
Calculates the path until completed or until the time has passed targetTick. | |
override void | Cleanup () |
Always called after the path has been calculated. | |
override string | DebugString (PathLog logMode) |
Returns a debug string for this path. | |
override uint | GetConnectionSpecialCost (GraphNode a, GraphNode b, uint currentCost) |
May be called by graph nodes to get a special cost for some connections. | |
Vector3 | GetMovementVector (Vector3 point) |
Returns in which direction to move from a point on the path. | |
override void | Initialize () |
Initializes the path. | |
override void | Prepare () |
Prepares the path. | |
override void | Reset () |
Reset all values to their default values. | |
void | ResetCosts (Path p) |
Resets End Node Costs. | |
Public Member Functions inherited from Path | |
void | AdvanceState (PathState s) |
Threadsafe increment of the state. | |
uint | CalculateHScore (GraphNode node) |
bool | CanTraverse (GraphNode node) |
Returns if the node can be traversed. | |
void | Claim (System.Object o) |
Claim this path. | |
void | Error () |
Aborts the path because of an error. | |
void | ForceLogError (string msg) |
Logs an error and calls Error(). | |
Int3 | GetHTarget () |
PathState | GetState () |
Returns the state of the path in the pathfinding pipeline. | |
uint | GetTagPenalty (int tag) |
Returns penalty for the given tag. | |
float | GetTotalLength () |
Total Length of the path. | |
uint | GetTraversalCost (GraphNode node) |
bool | IsDone () |
Returns if this path is done calculating. | |
void | Log (string msg) |
Appends a message to the errorLog. | |
void | LogError (string msg) |
Appends msg to errorLog and logs msg to the console. | |
virtual void | OnEnterPool () |
Called when the path enters the pool. | |
void | PrepareBase (PathHandler pathHandler) |
Prepares low level path variables for calculation. | |
void | Release (System.Object o) |
Releases a path claim. | |
void | ReleaseSilent (System.Object o) |
Releases the path silently. | |
virtual void | ReturnPath () |
Calls callback to return the calculated path. | |
IEnumerator | WaitForPath () |
Waits until this path has been calculated and returned. | |
Public Attributes | |
bool | calculatePartial = false |
Calculate partial path if the target node cannot be reached. | |
GraphNode | endHint |
Hints can be set to enable faster Get Nearest Node queries. | |
GraphNode | endNode |
End node of the path. | |
Vector3 | endPoint |
Exact end point of the path. | |
Vector3 | originalEndPoint |
End Point exactly as in the path request. | |
Vector3 | originalStartPoint |
Start Point exactly as in the path request. | |
bool | recalcStartEndCosts = true |
Defines if start and end nodes will have their connection costs recalculated for this path. | |
GraphNode | startHint |
Hints can be set to enable faster Get Nearest Node queries. | |
Int3 | startIntPoint |
Start point in integer coordinates. | |
GraphNode | startNode |
Start node of the path. | |
Vector3 | startPoint |
Exact start point of the path. | |
Public Attributes inherited from Path | |
OnPathDelegate | callback |
Callback to call when the path is complete. | |
System.DateTime | callTime |
When the call was made to start the pathfinding for this path. | |
float | duration |
The duration of this path in ms. | |
int | enabledTags = -1 |
Which graph tags are traversable. | |
int | height |
Height of the character. | |
Heuristic | heuristic |
Determines which heuristic to use. | |
float | heuristicScale = 1F |
Scale of the heuristic values. | |
OnPathDelegate | immediateCallback |
Immediate callback to call when the path is complete. | |
Path | next |
The next path to be searched. | |
NNConstraint | nnConstraint = PathNNConstraint.Default |
Constraint for how to search for nodes. | |
List< GraphNode > | path |
Holds the path as a Node array. | |
PathHandler | pathHandler |
Data for the thread calculating this path. | |
ushort | pathID |
ID of this path. | |
int | radius |
Radius for the unit searching for the path. | |
bool | recycled = false |
True if the path is currently recycled (i.e in the path pool). | |
int | searchedNodes |
Number of nodes this path has searched. | |
int | searchIterations = 0 |
int | speed |
Speed of the character. | |
int | turnRadius |
Turning radius of the character. | |
List< Vector3 > | vectorPath |
Holds the (perhaps post processed) path as a Vector3 array. | |
int | walkabilityMask = -1 |
A mask for defining what type of ground a unit can traverse, not used in any default standard graph. | |
Protected Member Functions | |
override void | Recycle () |
Recycle the path. | |
void | UpdateStartEnd (Vector3 start, Vector3 end) |
Sets the start and end points. | |
Protected Member Functions inherited from Path | |
bool | HasExceededTime (int searchedNodes, long targetTime) |
virtual void | Trace (PathNode from) |
Traces the calculated path from the end node to the start. | |
Protected Attributes | |
int[] | endNodeCosts |
Saved original costs for the end node. | |
bool | hasEndPoint = true |
Determines if a search for an end node should be done. | |
PathNode | partialBestTarget = null |
Current best target for the partial path. | |
Protected Attributes inherited from Path | |
PathNode | currentR |
The node currently being processed. | |
bool | hasBeenReset = false |
True if the Reset function has been called. | |
Int3 | hTarget |
Target to use for H score calculation. | |
GraphNode | hTargetNode |
int[] | internalTagPenalties = null |
The tag penalties that are actually used. | |
int[] | manualTagPenalties = null |
Tag penalties set by other scripts. | |
float | maxFrameTime |
The max number of milliseconds per iteration (frame, in case of non-multithreading) | |
Constructors | |
ABPath () | |
Default constructor. | |
static ABPath | Construct (Vector3 start, Vector3 end, OnPathDelegate callback=null) |
Construct a path with a start and end point. | |
void | Setup (Vector3 start, Vector3 end, OnPathDelegate callbackDelegate) |
Additional Inherited Members | |
Properties inherited from Path | |
PathCompleteState | CompleteState [get, set] |
Current state of the path. | |
bool | error [get] |
If the path failed, this is true. | |
string | errorLog [get] |
Log messages with info about eventual errors. | |
virtual bool | FloodingPath [get] |
int[] | tagPenalties [get, set] |
Penalties for each tag. | |
ABPath | ( | Vector3 | start, |
Vector3 | end, | ||
OnPathDelegate | callbackDelegate | ||
) |
ABPath | ( | ) |
Default constructor.
Do not use this. Instead use Pathfinding.PathPool<Pathfinding.Path>.GetPath()
If you want to use the constructor, use this:
And then use a Setup() method.
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virtual |
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).
Implements Path.
Reimplemented in MultiTargetPath, RandomPath, and FloodPathTracer.
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virtual |
Always called after the path has been calculated.
Guaranteed to be called before other paths have been calculated on the same thread. Use for cleaning up things like node tagging and similar.
Reimplemented from Path.
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static |
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virtual |
May be called by graph nodes to get a special cost for some connections.
Nodes may call it when PathNode.flag2 is set to true, for example mesh nodes, which have a very large area can be marked on the start and end nodes, this method will be called to get the actual cost for moving from the start position to its neighbours instead of as would otherwise be the case, from the start node's position to its neighbours. The position of a node and the actual start point on the node can vary quite a lot.
The default behaviour of this method is to return the previous cost of the connection, essentiall making no change at all.
This method should return the same regardless of the order of a and b. That is f(a,b) == f(b,a) should hold.
a | Moving from this node |
b | Moving to this node |
currentCost | The cost of moving between the nodes. Return this value if there is no meaningful special cost to return. |
Reimplemented from Path.
Vector3 GetMovementVector | ( | Vector3 | point | ) |
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 vectorPath) and then returns the direction to the next point from there. The direction is not normalized.
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virtual |
Initializes the path.
Sets up the open list and adds the first node to it
Implements Path.
Reimplemented in MultiTargetPath, RandomPath, and FloodPathTracer.
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virtual |
Prepares the path.
Searches for start and end nodes and does some simple checking if a path is at all possible
Implements Path.
Reimplemented in MultiTargetPath, and RandomPath.
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protectedvirtual |
Recycle the path.
Calling this means that the path and any variables on it are not needed anymore and the path can be pooled. All path data will be reset. Implement this in inheriting path types to support recycling of paths.
Implements Path.
Reimplemented in MultiTargetPath, RandomPath, FloodPathTracer, and FleePath.
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virtual |
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 ();
Reimplemented from Path.
Reimplemented in FloodPathTracer, and RandomPath.
void ResetCosts | ( | Path | p | ) |
Resets End Node Costs.
Costs are updated on the end node at the start of the search to better reflect the end point passed to the path, the previous ones are saved in endNodeCosts and are reset in this function which is called after the path search is complete
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protected |
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protected |
Sets the start and end points.
Sets originalStartPoint, originalEndPoint, startPoint, endPoint, startIntPoint and hTarget (to end )
bool calculatePartial = false |
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.
GraphNode endHint |
Hints can be set to enable faster Get Nearest Node queries.
Only applies to some graph types
GraphNode endNode |
End node of the path.
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protected |
Saved original costs for the end node.
Vector3 endPoint |
Exact end point of the path.
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protected |
Determines if a search for an end node should be done.
Set by different path types.
Vector3 originalEndPoint |
End Point exactly as in the path request.
Vector3 originalStartPoint |
Start Point exactly as in the path request.
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protected |
Current best target for the partial path.
This is the node with the lowest H score
bool recalcStartEndCosts = true |
Defines if start and end nodes will have their connection costs recalculated for this path.
These connection costs will be more accurate and based on the exact start point and target point, however it should not be used when connection costs are not the default ones (all build in graph generators currently generate default connection costs).
GraphNode startHint |
Hints can be set to enable faster Get Nearest Node queries.
Only applies to some graph types
Int3 startIntPoint |
Start point in integer coordinates.
GraphNode startNode |
Start node of the path.
Vector3 startPoint |
Exact start point of the path.