/// <summary>
/// When an entity moves around we'll remove it from its old node and add it to its new node (if applicable)
/// </summary>
/// <param name="moveEvent"></param>
private void HandleEntityMove(MoveEvent moveEvent)
{
// If we've moved to space or the likes then remove us.
if (moveEvent.Sender.Deleted ||
!moveEvent.Sender.TryGetComponent(out IPhysicsComponent physics) ||
!PathfindingNode.IsRelevant(moveEvent.Sender, physics))
{
HandleEntityRemove(moveEvent.Sender);
return;
}
// Memory leak protection until grid parenting confirmed fix / you REALLY need the performance
var gridBounds = _mapManager.GetGrid(moveEvent.Sender.Transform.GridID).WorldBounds;
if (!gridBounds.Contains(moveEvent.Sender.Transform.WorldPosition))
{
HandleEntityRemove(moveEvent.Sender);
return;
}
// If we move from space to a grid we may need to start tracking it.
if (!_lastKnownPositions.TryGetValue(moveEvent.Sender, out var oldNode))
{
HandleEntityAdd(moveEvent.Sender);
return;
}
var newGridId = moveEvent.NewPosition.GetGridId(_entityManager);
if (newGridId == GridId.Invalid)
{
HandleEntityRemove(moveEvent.Sender);
return;
}
// The pathfinding graph is tile-based so first we'll check if they're on a different tile and if we need to update.
// If you get entities bigger than 1 tile wide you'll need some other system so god help you.
var newTile = _mapManager.GetGrid(newGridId).GetTileRef(moveEvent.NewPosition);
if (oldNode == null || oldNode.TileRef == newTile)
{
return;
}
var newNode = GetNode(newTile);
_lastKnownPositions[moveEvent.Sender] = newNode;
oldNode.RemoveEntity(moveEvent.Sender);
newNode.AddEntity(moveEvent.Sender, physics);
}
/// <summary>
/// Tries to add the entity to the relevant pathfinding node
/// </summary>
/// The node will filter it to the correct category (if possible)
/// <param name="entity"></param>
private void HandleEntityAdd(IEntity entity)
{
if (entity.Deleted ||
_lastKnownPositions.ContainsKey(entity) ||
!entity.TryGetComponent(out IPhysicsComponent physics) ||
!PathfindingNode.IsRelevant(entity, physics))
{
return;
}
var grid = _mapManager.GetGrid(entity.Transform.GridID);
var tileRef = grid.GetTileRef(entity.Transform.Coordinates);
var chunk = GetChunk(tileRef);
var node = chunk.GetNode(tileRef);
node.AddEntity(entity, physics);
_lastKnownPositions.Add(entity, node);
}