private void AddAdjacentCellToOpenList(Node parentNode, int gCost, int cellIndex)
{
/* TODO:
* 1) Create a new node with the cellIndex and parentNode, include the G and H values for the node
* 2) calculate F for the node
* 2) finally add to open list
*/
}
private void ExploreNode(Node parentNode, int columnOffset, int rowOffset, int gCost)
{
var adjacentCellIndex = _map.GetAdjacentCellIndex(parentNode.CellIndex, columnOffset, rowOffset);
// Ignore unwalkable nodes (or nodes outside the grid)
if (adjacentCellIndex == -1)
return;
// TODO: Ignore nodes on the closed list
if (OpenUpdatePathCost(parentNode, gCost, adjacentCellIndex))
return;
AddAdjacentCellToOpenList(parentNode, gCost, adjacentCellIndex);
}
public void CalculatePath()
{
/*
* TODO:
* 1) Create the first node using the StartCell property in Map, the parent should be null since its the starting node
* 2) set the _current node to the node you just created
*/
var node = new Node(_map.StartCell, null);
_openList.Add(node);
_currentNode = node;
while (true)
{
/* TODO
* if the open list has no nodes in it break out of the loop
*
* Find the Node with the smallest F in the open list and set it to _currentNode
* If that node has the same cell index as the target cell (in _map) break out of the loop
*
* Remove the _currentNode from the open list and add it to the closed list
* Add all of the nodes adjacent to the _currentNode to the open list
*
*
*/
ExploreNode(_currentNode, -1, -1, 14);
ExploreNode(_currentNode, 0, -1, 10);
ExploreNode(_currentNode, 1, -1, 14);
ExploreNode(_currentNode, -1, 0, 10);
ExploreNode(_currentNode, 1, 0, 10);
ExploreNode(_currentNode, -1, 1, 14);
ExploreNode(_currentNode, 0, 1, 10);
ExploreNode(_currentNode, 1, 1, 14);
}
_map.HighlightPath(_currentNode);
}
public void HighlightPath(Node node)
{
var currentNode = node;
while (currentNode != null)
{
_path.Add(currentNode.CellIndex);
currentNode = currentNode.Parent;
}
}
private bool OpenUpdatePathCost(Node parentNode, int gCost, int cellIndex)
{
var adjacentNode = _openList.SingleOrDefault(n => n.CellIndex == cellIndex);
if (adjacentNode != null)
{
if (parentNode.G + gCost < adjacentNode.G)
{
adjacentNode.Parent = parentNode;
/*
* TODO: calculate the values of G and H for adjacentNode
*/
}
return true;
}
return false;
}
private void UpdatePathCost(int cellIndex, Node parentNode, int gCost)
{
var adjacentNode = _openList.SingleOrDefault(n => n.CellIndex == cellIndex);
if (parentNode.G + gCost < adjacentNode.G)
{
adjacentNode.Parent = parentNode;
/*
* TODO: calculate the values of G and H for adjacentNode
*/
}
}