/// <summary>
/// Creates searchNodes for all the tiles and connect them to their neighbours
/// </summary>
private void InitializeSearchNodes(Map map)
{
searchNodes = new SearchNode[width, height];
//Create nodes
for (int x = 0; x < width; x++)
{
for (int y = 0; y < height; y++)
{
SearchNode node = new SearchNode(new Point(x, y), map);
if (node.walkable == true)
{
node.neighbors = new SearchNode[4];
searchNodes[x, y] = node;
}
}
}
//Connect nodes to neighbours
for (int x = 0; x < width; x++)
{
for (int y = 0; y < height; y++)
{
SearchNode node = searchNodes[x, y];
// If not relevant node, skip to next.
if (node == null || node.walkable == false)
{
continue;
}
Point[] neighbours = new Point[] {
new Point (x, y - 1), // The node above the current node.
new Point (x, y + 1), // The node below the current node.
new Point (x - 1, y), // The node left of the current node.
new Point (x + 1, y), // The node right of the current node.
};
for (int i = 0; i < neighbours.Length; i++)
{
Point position = neighbours[i];
// If position is not valid, skip to next.
if (position.X < 0 || position.X > width - 1 || position.Y < 0 || position.Y > height - 1)
{
continue;
}
SearchNode neighbour = searchNodes[position.X, position.Y];
// If unit can not walk on node, skip to next.
if (neighbour == null || neighbour.walkable == false)
{
continue;
}
node.neighbors[i] = neighbour;
}
}
}
}
/// <summary>
/// After arriving at the end node, follow path back from endNode to find shortest path.
/// </summary>
private List<Vector2> FindFinalPath(SearchNode startNode, SearchNode endNode)
{
List<Vector2> finalPath = new List<Vector2>();
closedList.Add(endNode);
SearchNode parentNode = endNode.parent;
// Add nodes in path to the closedList in reverse order.
while (parentNode != startNode)
{
closedList.Add(parentNode);
parentNode = parentNode.parent;
}
// Add nodes to final path as coordinates in the correct order.
for (int i = closedList.Count - 1; i >= 0; i--)
{
finalPath.Add(new Vector2(closedList[i].position.X * Map.TILESIZE, closedList[i].position.Y * Map.TILESIZE));
}
return finalPath;
}
