public List<Tile> SearchPath(bool diagonal = true)
{
int i;
for (i = 0; i < tiles.Count; i++)
{
if (tiles[i].Type == 1)
start = new Node(tiles[i].ID, null);
if (tiles[i].Type == 2)
end = new Node(tiles[i].ID, null);
}
openList.Add(start);
current = start;
while (true)
{
if (openList.Count == 0)
break;
current = FindSmallestF();
if (current.CellIndex == end.CellIndex)
break;
openList.Remove(current);
closedList.Add(current);
if (diagonal)
{
//Diagonal
AddAdjacentCellToOpenList(current, 1, -1, 14);
AddAdjacentCellToOpenList(current, -1, -1, 14);
AddAdjacentCellToOpenList(current, -1, 1, 14);
AddAdjacentCellToOpenList(current, 1, 1, 14);
}
//Straight
AddAdjacentCellToOpenList(current, 0, -1, 10);
AddAdjacentCellToOpenList(current, -1, 0, 10);
AddAdjacentCellToOpenList(current, 1, 0, 10);
AddAdjacentCellToOpenList(current, 0, 1, 10);
}
while (current != null)
{
bool endOnClosed = false;
for (int v = 0; v < openList.Count; v++)
if (openList[v].CellIndex == end.CellIndex)
endOnClosed = true;
if (endOnClosed && tiles[current.CellIndex].Type != 2 && tiles[current.CellIndex].Type != 1)
tiles[current.CellIndex].Type = 4;
current = current.Parent;
}
return tiles;
}
private void AddAdjacentCellToOpenList(Node parentNode, int columnOffset, int rowOffset, int gCost)
{
var adjacentCellIndex = GetAdjacentCellIndex(parentNode.CellIndex, columnOffset, rowOffset);
// ignore unwalkable nodes (or nodes outside the grid)
if (adjacentCellIndex == -1)
return;
// ignore nodes on the closed list
if (closedList.Any(n => n.CellIndex == adjacentCellIndex))
return;
var adjacentNode = openList.SingleOrDefault(n => n.CellIndex == adjacentCellIndex);
if (adjacentNode != null)
{
if (parentNode.G + gCost < adjacentNode.G)
{
adjacentNode.Parent = parentNode;
adjacentNode.G = parentNode.G + gCost;
adjacentNode.F = adjacentNode.G + adjacentNode.H;
}
return;
}
var node = new Node(adjacentCellIndex, parentNode) { G = gCost, H = GetDistance(adjacentCellIndex, end.CellIndex) };
node.F = node.G + node.H;
openList.Add(node);
}
public Node(int cellIndex, Node parent)
{
CellIndex = cellIndex;
Parent = parent;
}