// TODO Add support for LineOfSight to take line width into account
private bool LineOfSight(PathfindingNode nodeA, PathfindingNode nodeB)
{
// Simple limit to the number of cells that can checked in one call
// Prevents runaway computation
// TODO Make sure excecution always terminates so this hard limit can be removed
int limit = 100;
int count = 0;
List <PathfindingNode> intersectedNodes = new List <PathfindingNode>();
var dir = ((Vector2)(nodeB.GridPosition - nodeA.GridPosition)).normalized;
int signX = Math.Sign(dir.x);
int signY = Math.Sign(dir.y);
float slope = dir.y / dir.x;
var currentCell = nodeA;
Vector2 lastIntersection = nodeA.GridPosition;
float nextX = nodeA.GridPosition.x + 0.5f * signX;
float nextY = nodeA.GridPosition.y + 0.5f * signY;
intersectedNodes.Add(currentCell);
while (currentCell != nodeB)
{
if (count >= limit)
{
return(false);
}
float y = (nextX - lastIntersection.x) * slope + lastIntersection.y;
Vector2 xInt = new Vector2(nextX, y);
float tx = dir.x == 0 ? Mathf.Infinity : Vector2.Distance(lastIntersection, xInt);
float x = (nextY - lastIntersection.y) / slope + lastIntersection.x;
Vector2 yInt = new Vector2(x, nextY);
float ty = dir.y == 0 ? Mathf.Infinity : Vector2.Distance(lastIntersection, yInt);
if (tx == ty)
{
currentCell = NodeAtGridPosition((signX == 1 ? Mathf.CeilToInt(nextX) : Mathf.FloorToInt(nextX)),
(signY == 1 ? Mathf.CeilToInt(nextY) : Mathf.FloorToInt(nextY)));
intersectedNodes.Add(currentCell);
intersectedNodes.Add(NodeAtGridPosition(Mathf.FloorToInt(nextX), Mathf.CeilToInt(nextY)));
intersectedNodes.Add(NodeAtGridPosition(Mathf.CeilToInt(nextX), Mathf.FloorToInt(nextY)));
lastIntersection = xInt;
nextX += 1 * signX;
nextY += 1 * signY;
}
else if (tx < ty)
{
currentCell = NodeAtGridPosition((signX == 1 ? Mathf.CeilToInt(nextX) : Mathf.FloorToInt(nextX)),
(signY == 1 ? Mathf.FloorToInt(nextY) : Mathf.CeilToInt(nextY)));
intersectedNodes.Add(currentCell);
lastIntersection = xInt;
nextX += 1 * signX;
}
else
{
currentCell = NodeAtGridPosition((signX == 1 ? Mathf.FloorToInt(nextX) : Mathf.CeilToInt(nextX)),
(signY == 1 ? Mathf.CeilToInt(nextY) : Mathf.FloorToInt(nextY)));
intersectedNodes.Add(currentCell);
lastIntersection = yInt;
nextY += 1 * signY;
}
count++;
}
return(intersectedNodes.All(n => n.IsWalkable));
}
public void Reset()
{
Parent = null;
GCost = Mathf.Infinity;
HCost = Mathf.Infinity;
}
public float NonWalkableNeighborsCost(PathfindingNode node)
{
List <PathfindingNode> nonWalkableNeighbors = GetNeighbors(node).Where(neighbor => !neighbor.IsWalkable).ToList();
return(nonWalkableNeighbors.Count);
}
