public PathNode(PathNode pt, Point c, Point end)
{
cell = c;
parent = pt;
hscore = PointM.Sum(PointM.Add(end, -c.X, -c.Y));
closed = false;
}
/// <summary>
/// Generates a path through the array
/// </summary>
/// <typeparam name="E">Type of the array</typeparam>
/// <param name="arr">The array</param>
/// <param name="start">The starting position</param>
/// <param name="end">The target position</param>
/// <param name="isPathable">Delegate to check pathability using input (fromPoint, toPoint)</param>
/// <param name="GetFScore">Delegate to get movement score using input (V1, V2, P1, P2)</param>
/// <param name="diagonal">Boolean to determine ability to move diagonally</param>
/// <returns>Returns the shortest path from start to end</returns>
public static GenericPath GeneratePath <E>(E[,] arr, Point start, Point end, Func <Point, Point, bool> isPathable, Func <E, E, Point, Point, float> GetFScore, bool diagonal)
{
PathNode[,] nodes = new PathNode[arr.GetLength(0), arr.GetLength(1)];
MinHeap <PathNode> openHeap = new MinHeap <PathNode>(Comparer <PathNode> .Default);
nodes[start.X, start.Y] = new PathNode(null, start, end);
nodes[start.X, start.Y].fscore = 0;
openHeap.Add(nodes[start.X, start.Y]);
bool done = false;
do
{
PathNode current = openHeap.ExtractDominating();
foreach (Point p in diagonal ? dincrements : increments)
{
Point next = PointM.Add(current.cell, p.X, p.Y);
if (PointM.Assure(next, 0, arr.GetLength(0), 0, arr.GetLength(1)))
{
if (isPathable(current.cell, next))
{
float tfscore = current.fscore + GetFScore(arr[current.cell.X, current.cell.Y], arr[next.X, next.Y], current.cell, next);
if ((nodes[next.X, next.Y] != null && (!nodes[next.X, next.Y].closed && nodes[next.X, next.Y].fscore > tfscore)) || nodes[next.X, next.Y] == null)
{
nodes[next.X, next.Y] = new PathNode(current, next, end);
nodes[next.X, next.Y].fscore = tfscore;
openHeap.Add(nodes[next.X, next.Y]);
if (next.Equals(end))
{
done = true;
}
}
}
}
}
} while (!done && openHeap.Count > 0);
if (openHeap.Count != 0)
{
return(nodes[end.X, end.Y].GeneratePath());
}
return(null);
}
