public void CalculateCost(Node_script parent, Node_script goal, int gCost)
{
this.Parent = parent;
this.G = (parent.G + gCost);
this.H = (Mathf.Abs((this.Position.Column - goal.Position.Column) + (this.Position.Row - goal.Position.Row)) * 10);
this.F = (this.G + this.H);
}
private void VisualizeParent(Node_script node, Vector2 worldPosition)
{
if (node.Parent != null)
{
GameObject arrow = Instantiate(this._arrowPrefab, worldPosition, Quaternion.identity);
arrow.transform.SetParent(this.transform);
// RIGHT
if ((node.Position.Column < node.Parent.Position.Column) && (node.Position.Row == node.Parent.Position.Row))
{
arrow.transform.eulerAngles = new Vector3(0, 0, 0);
// RIGHT-DOWN
}
else if ((node.Position.Column < node.Parent.Position.Column) && (node.Position.Row < node.Parent.Position.Row))
{
arrow.transform.eulerAngles = new Vector3(0, 0, -45);
// RIGHT-UP
}
else if ((node.Position.Column < node.Parent.Position.Column) && (node.Position.Row > node.Parent.Position.Row))
{
arrow.transform.eulerAngles = new Vector3(0, 0, 45);
// LEFT
}
else if ((node.Position.Column > node.Parent.Position.Column) && (node.Position.Row == node.Parent.Position.Row))
{
arrow.transform.eulerAngles = new Vector3(0, 0, 180);
// LEFT-DOWN
}
else if ((node.Position.Column > node.Parent.Position.Column) && (node.Position.Row < node.Parent.Position.Row))
{
arrow.transform.eulerAngles = new Vector3(0, 0, -135);
// LEFT-UP
}
else if ((node.Position.Column > node.Parent.Position.Column) && (node.Position.Row > node.Parent.Position.Row))
{
arrow.transform.eulerAngles = new Vector3(0, 0, 135);
// DOWN
}
else if ((node.Position.Column == node.Parent.Position.Column) && (node.Position.Row < node.Parent.Position.Row))
{
arrow.transform.eulerAngles = new Vector3(0, 0, -90);
// UP
}
else if ((node.Position.Column == node.Parent.Position.Column) && (node.Position.Row > node.Parent.Position.Row))
{
arrow.transform.eulerAngles = new Vector3(0, 0, 90);
}
_arrows.Add(arrow);
}
}
private static bool IsMoveAllowed(Node_script currentNode, Node_script neighbor)
{
GridPosition_script direction = (neighbor.Position - currentNode.Position);
GridPosition_script first = new GridPosition_script(currentNode.Position.Row, (currentNode.Position.Column + direction.Column));
GridPosition_script second = new GridPosition_script((currentNode.Position.Row + direction.Row), currentNode.Position.Column);
if (TileMap_script.Instance.IsWithinBounds(first) && !TileMap_script.Instance.Tiles[first].IsWalkable)
{
return(false);
}
if (TileMap_script.Instance.IsWithinBounds(second) && !TileMap_script.Instance.Tiles[second].IsWalkable)
{
return(false);
}
return(true);
}
public static Stack <Node_script> GetPath(GridPosition_script startPosition, GridPosition_script goalPosition)
{
if (_nodes == null)
{
CreateNodes();
}
int gCost;
Node_script neighbor;
GridPosition_script neighborPosition;
Node_script currentNode = _nodes[startPosition];
Node_script goalNode = _nodes[goalPosition];
HashSet <Node_script> openList = new HashSet <Node_script>();
HashSet <Node_script> closedList = new HashSet <Node_script>();
Stack <Node_script> path = new Stack <Node_script>();
openList.Add(currentNode);
while (openList.Count > 0)
{
// GET THE NODE WITH THE LOWEST F COST
currentNode = openList.OrderBy(n => n.F).First();
// GOAL REACHED
if (currentNode == goalNode)
{
// RECONSTRUCT PATH BY BACKTRACING PARENTS
path.Push(currentNode);
while (currentNode.Parent != null)
{
currentNode = currentNode.Parent;
path.Push(currentNode);
}
break;
}
// COSE CURRENT
openList.Remove(currentNode);
closedList.Add(currentNode);
// OPEN NEIGHBORS
for (int row = -1; row <= 1; row++)
{
for (int column = -1; column <= 1; column++)
{
neighborPosition = new GridPosition_script(currentNode.Position.Row - row, currentNode.Position.Column - column);
// SKIP OUT-OF-BOUNDS, UNWALKABLES AND CURRENT NODE
if (TileMap_script.Instance.IsWithinBounds(neighborPosition) &&
(TileMap_script.Instance.Tiles[neighborPosition].IsWalkable) && (neighborPosition != currentNode.Position))
{
neighbor = _nodes[neighborPosition];
// SKIP CLOSED NODE
if (closedList.Contains(neighbor))
{
continue;
}
// HORIZONTAL/VERTICAL
if (Mathf.Abs(column - row) == 1)
{
gCost = 10;
// DIAGONAL
}
else
{
if (!IsMoveAllowed(currentNode, neighbor))
{
continue;
}
gCost = 14;
}
// NEW/UNVISITED
if (!openList.Contains(neighbor))
{
openList.Add(neighbor);
// SKIP IF NOT BETTER
}
else if ((currentNode.G + gCost) >= neighbor.G)
{
continue;
}
// UPDATE COST
neighbor.CalculateCost(currentNode, goalNode, gCost);
}
}
}
}
_nodes.Clear();
_nodes = null;
//// VIZUALIZE OPEN LIST
//GameObject.Find("AstarTest_object").GetComponent<AstarTest_script>().Visualize(openList, Color.yellow);
//GameObject.Find("AstarTest_object").GetComponent<AstarTest_script>().Visualize(closedList, Color.cyan);
//GameObject.Find("AstarTest_object").GetComponent<AstarTest_script>().Visualize(path, Color.blue);
return(path);
}
public void Visualize(Node_script node, Color color)
{
node.TileScript.SpriteRenderer.color = color;
}
