/// <summary>
/// Modifies the input path by removing any nodes which are not neccesarry for the path to still be valid.
/// </summary>
public NavTilePath ModifyPath(NavTilePath inPath)
{
// If the path is too short, return the path as is.
if (inPath.Count <= 2)
{
return(inPath);
}
NavTilePath modifiedPath = inPath;
// Iterate over all nodes between start and finish.
// (i < inPath.Count - 1) is deliberate, since the last iteration needs to be the node before the last one.
for (int i = 1; i < modifiedPath.Count - 1;)
{
Vector2Int before = modifiedPath[i - 1].TilePosition;
Vector2Int after = modifiedPath[i + 1].TilePosition;
if (IsWalkable(before, after, inPath.AreaMask))
{
// If the area between the 2 points is walkable, remove the point in between.
// Don't increment 'i' as the next node will be on the current index.
modifiedPath.RemoveAt(i);
}
else
{
// If the tile can't be removed, move to the next one
i++;
}
}
return(modifiedPath);
}
/// <summary>
/// Converts a list of coordinates to a path with world positions.
/// </summary>
/// <param name="inPathInCoordinates">List of 2D coordinates on the grid.</param>
/// <param name="inAreaMask">Area mask to associate with the path. Currently used for smoothing.</param>
/// <returns>The path with world positions.</returns>
protected NavTilePath ConvertCoordinatesToPath(List <Vector2Int> inPathInCoordinates, int inAreaMask)
{
NavTilePath path = new NavTilePath();
for (int i = inPathInCoordinates.Count - 1; i >= 0; i--)
{
path.Add(inPathInCoordinates[i]);
}
path.AreaMask = inAreaMask;
return(path);
}
public void CancelPath()
{
if (_followingPathCoroutine != null)
{
StopCoroutine(_followingPathCoroutine);
_pathStatus = EPathStatus.NotAvailable;
_movementStatus = EMovementStatus.Stationary;
UpdateTileOccupancy(_occupyingTilePosition, NavTileManager.Instance.SurfaceManager.Grid.WorldToCell(transform.position).GetVector2Int());
}
_path = null;
}
/// <summary>
/// Executes the pipeline on the Unity main thread.
/// </summary>
/// <param name="inInput">Input parameters for the path.</param>
private NavTilePath DoLinearPipeline(FindPathInput inInput)
{
if (_algorithm == null)
{
Type algorithm = Type.GetType(AlgorithmType);
_algorithm = Activator.CreateInstance(algorithm) as IPathfindingAlgorithm;
}
NavTilePath path = _algorithm.FindPath(inInput);
foreach (var smoothingAlgorithm in EnabledSmoothingAlgorithms)
{
var instance = Activator.CreateInstance(Type.GetType(smoothingAlgorithm)) as INavTilePathModifier;
path = instance.ModifyPath(path);
}
return(path);
}
/// <summary>
/// Coroutine for following a given path.
/// </summary>
/// <param name="inPath">The path that should be followed.</param>
private IEnumerator FollowPath(NavTilePath inPath)
{
if (inPath == null)
{
yield break;
}
// Prepare path traversal.
_currentPathNodeIndex = 0;
PathNode currentNode = new PathNode(transform.position);
PathNode nextNode = inPath[_currentPathNodeIndex];
_pathStatus = EPathStatus.Traversing;
_movementStatus = EMovementStatus.Traversing;
float timeInPath = 0;
float timeInCurrentNode = 0;
float currentSpeed = GetAreaSpeed(nextNode.GetAreaIndex());
OnAreaChangeUnityEvent.Invoke(nextNode.GetAreaIndex());
float timeToNextNode = inPath.GetDurationBetweenNodes(currentNode, nextNode, currentSpeed);
// Initial animation triggers.
SetAnimationParameters(nextNode.WorldPosition - currentNode.WorldPosition, currentSpeed);
// Do conflict handling if enabled
if (_conflictOption != EConflictOptions.Disabled)
{
// Check if there is a conflict before starting to traverse.
EConflictStatus conflictStatus;
EAbortReason abortReason;
do
{
conflictStatus = HandleConflict(currentNode, nextNode, out abortReason);
// In case the conflict is not completely resolved, yield the coroutine and check again next frame.
if (conflictStatus == EConflictStatus.Processing)
{
_movementStatus = EMovementStatus.Waiting;
yield return(null);
}
else if (conflictStatus == EConflictStatus.Abort) // In case the conflict cannot be resolved, abort path traversing.
{
_pathStatus = EPathStatus.NotAvailable;
_movementStatus = EMovementStatus.Stationary;
OnPathAbortedUnityEvent.Invoke(abortReason, nextNode.TilePosition);
yield break;
}
} while (conflictStatus == EConflictStatus.Processing); // If this is false, the 'do-while' will stop and thus a conflict has not been encountered.
}
// Start traversing.
while (true)
{
// Check if the agent will reach the next node in this frame or not.
// If so, start walking towards the subsequent node.
if (timeInCurrentNode + Time.deltaTime >= timeToNextNode)
{
// Switch to next node.
_currentPathNodeIndex++;
// Goal reached?
if (_currentPathNodeIndex == inPath.Count)
{
transform.position = nextNode.WorldPosition;
_pathStatus = EPathStatus.NotAvailable;
_movementStatus = EMovementStatus.Stationary;
// Reset animation parameters.
ResetAnimationParameters();
OnPathFinishedUnityEvent.Invoke();
yield break;
}
currentNode = nextNode;
nextNode = inPath[_currentPathNodeIndex];
// The 'previous' position is the tile which the agent is walking from.
_previousPosition = currentNode.TilePosition;
// Check if next tile is still walkable.
if (!NavTileManager.Instance.SurfaceManager.Data.IsTileWalkable(nextNode.TilePosition, AreaMask))
{
OnPathAbortedUnityEvent.Invoke(EAbortReason.EncounteredObstruction, nextNode.TilePosition);
yield break;
}
// Check for conflicts if enabled.
if (_conflictOption != EConflictOptions.Disabled)
{
// Check if there is a conflict on the next node.
EConflictStatus conflictStatus;
EAbortReason abortReason;
do
{
conflictStatus = HandleConflict(currentNode, nextNode, out abortReason);
// In case the conflict is not completely resolved, yield the coroutine and check again next frame.
if (conflictStatus == EConflictStatus.Processing)
{
_movementStatus = EMovementStatus.Waiting;
yield return(null);
}
else if (conflictStatus == EConflictStatus.Abort) // In case the conflict cannot be resolved, abort path traversing.
{
_pathStatus = EPathStatus.NotAvailable;
_movementStatus = EMovementStatus.Stationary;
OnPathAbortedUnityEvent.Invoke(abortReason, nextNode.TilePosition);
yield break;
}
} while (conflictStatus == EConflictStatus.Processing); // If this is false, the 'do-while' will stop and thus a conflict has not been encountered.
// Set movementstatus just in case it has been changed due to a conflict.
_movementStatus = EMovementStatus.Traversing;
}
// Check whether the agent has changed areas.
int nextAreaIndex = nextNode.GetAreaIndex();
if (currentNode.GetAreaIndex() != nextAreaIndex)
{
currentSpeed = GetAreaSpeed(nextAreaIndex);
OnAreaChangeUnityEvent.Invoke(nextAreaIndex);
}
// Calculate the time which might be left over from the previous node to already move in towards the subsequent node.
// This prevents the agent to first exactly stop on a tile before starting to move again, creating jittering.
timeInCurrentNode += Time.deltaTime - timeToNextNode;
timeToNextNode = inPath.GetDurationBetweenNodes(currentNode, nextNode, currentSpeed);
transform.position = Vector3.Lerp(currentNode.WorldPosition, nextNode.WorldPosition, timeInCurrentNode / timeToNextNode);
// Set animation parameters
SetAnimationParameters(nextNode.WorldPosition - currentNode.WorldPosition, currentSpeed);
yield return(null);
}
else // The next node has not been reached, so keep moving towards it.
{
timeInPath += Time.deltaTime;
timeInCurrentNode += Time.deltaTime;
transform.position = Vector3.Lerp(currentNode.WorldPosition, nextNode.WorldPosition, timeInCurrentNode / timeToNextNode);
yield return(null);
}
}
}
/// <summary>
/// Moves the agent to a tile position
/// </summary>
/// <param name="inTargetPosition">The position to move to as a tile position.</param>
public async void MoveToPosition(Vector2Int inTargetPosition, params Vector2Int[] inAvoidTiles)
{
// Check for early exits or possible errors first
if (NavTileManager.Instance.SurfaceManager.Grid == null)
{
Debug.LogWarning("There is no (or multiple) grid object(s) found in the scene. Path can't be calculated without one.");
OnPathNotFoundUnityEvent.Invoke();
return;
}
if (!NavTileManager.Instance.SurfaceManager.IsDataInitialized || NavTileManager.Instance.SurfaceManager.Data.HasNoTiles)
{
Debug.LogWarning("Data is not initialized for this scene. Please bake in the navigation 2D window.");
OnPathNotFoundUnityEvent.Invoke();
return;
}
Vector2Int startCoordinate = NavTileManager.Instance.SurfaceManager.Grid.WorldToCell(this.transform.position).GetVector2Int();
if (startCoordinate == inTargetPosition)
{
Debug.LogWarning("Trying to find a path to the start node. Calculating a path is redundant.");
OnPathNotFoundUnityEvent.Invoke();
return;
}
if (NavTileManager.Instance.SurfaceManager.Data.GetTileData(inTargetPosition) == null)
{
Debug.LogWarning(string.Format("Coordinate {0} is not a tile on the grid, can't calculate path.", inTargetPosition));
OnPathNotFoundUnityEvent.Invoke();
return;
}
// Start calculating a path.
_pathStatus = EPathStatus.Calculating;
// Intialize parameters to find a path.
FindPathInput input = new FindPathInput(startCoordinate, inTargetPosition, _areaMask, this._diagonalAllowed, this._cutCorners, this._ignoreTileCost, inAvoidTiles);
#if UNITY_EDITOR
input.Visualizer = visualizer;
#endif
// Get a path based on the input and the Pipeline Settings in the Navigation2D window.
_path = await NavTileManager.Instance.GetPath(input);
// If no path is found, return.
if (_path == null || _path.Count == 0)
{
Debug.LogWarning("Path could not be found.", gameObject);
_pathStatus = EPathStatus.NotAvailable;
OnPathNotFoundUnityEvent.Invoke();
return;
}
OnPathFound();
}