public Node(Vector2 position, Node parent, Vector2 target)
{
this.position = position;
this.parent = parent;
if (parent == null)
this.g = 0;
else
this.g = parent.g + 1;
Vector2 difference = target - position;
this.h = (int)(Math.Abs(difference.X) + Math.Abs(difference.Y));
this.f = this.g + this.h;
}
public static List<Vector2> createPath(List<Tile> map, Vector2 start, Vector2 end)
{
List<Node> openList, closedList;
openList = new List<Node>();
closedList = new List<Node>();
Node startNode = new Node(start, null, end);
foreach (Tile tile in map)
{
if (!tile.walkable && tile.position == end)
return new List<Vector2>();
if (tile.walkable && Vector2.Distance(tile.position, start) == 1)
openList.Add(new Node(tile.position, startNode, end));
}
closedList.Add(startNode);
while (listContains(closedList, end) == null)
{
Node selected = lowestF(openList, closedList);
if (openList.Count == 0)
break;
foreach (Tile tile in map)
{
//Adjacent node
if (tile.walkable && Vector2.Distance(tile.position, selected.position) == 1)
{
Node adjacentInOpenList;
if ((adjacentInOpenList = listContains(openList, tile.position)) != null)
if (adjacentInOpenList.g < selected.g)
{
openList.Remove(adjacentInOpenList);
adjacentInOpenList = new Node(adjacentInOpenList.position, selected, end);
openList.Add(adjacentInOpenList);
}
//Not in the closed or open list, so add it
if (listContains(openList, tile.position) == null && listContains(closedList, tile.position) == null)
openList.Add(new Node(tile.position, selected, end));
}
}
}
List<Vector2> path = new List<Vector2>();
if (openList.Count == 0)
return path;
Node tempNode = listContains(closedList, end);
path.Add(tempNode.position);
while (tempNode != null) //The startNode's parent is null
{
path.Add(tempNode.position);
tempNode = tempNode.parent;
}
path.Reverse();
return path;
}
static Node lowestF(List<Node> openList, List<Node> closedList)
{
Node ret = new Node(Vector2.Zero, null, Vector2.Zero);
ret.f = int.MaxValue;
foreach (Node node in openList)
if (node.f < ret.f)
ret = node;
if (ret.f == int.MaxValue)
ret = null;
else
{
openList.Remove(ret);
closedList.Add(ret);
}
return ret;
}
private void makeMatrix()
{
for (int i = 0; i < 9; i++)
{
for (int j = 0; j < 9; j++)
{
Node node = new Node();
//Neu node o phia tren nho hon hoac bang 0 thi gan la true,nguoc lai la false
if (i - 1 >= 0)
{
if (input[i - 1, j] <= 0)
{
node.setAdjacency(0, 9*(i-1)+j);
}
else
{
node.setAdjacency(0, -1);
}
}
//Neu node o phia trai nho hon hoac bang 0 thi gan la true,nguoc lai la false
if (j - 1 >= 0)
{
if (input[i, j - 1] <= 0)
{
node.setAdjacency(0, 9*i+j-1);
}
else
{
node.setAdjacency(0, -1);
}
}
//Neu node o phia duoi nho hon hoac bang 0 thi gan la true,nguoc lai la false
if (i + 1 < 9)
{
if (input[i + 1, j] <= 0)
{
node.setAdjacency(0, 9*(i+1)+j);
}
else
{
node.setAdjacency(0, -1);
}
}
//Neu node o phia phai nho hon hoac bang 0 thi gan la true,nguoc lai la false
if (j + 1 < 9)
{
if (input[i, j + 1] <= 0)
{
node.setAdjacency(0, 9*i+j+1);
}
else
{
node.setAdjacency(0, -1);
}
}
matrix[i, j] = node;
}
}
}
