/// <summary>
/// Create a new instance of the grid, instantiating the corresponding active algorithms nodes.
/// </summary>
public void CreateGrid()
{
CheckExistingGrid();
grid = new Node[gridSizeX, gridSizeY];
Vector2 bottomLeft = (Vector2)transform.position - Vector2.right * gridWorldSize.x / 2 - Vector2.up * gridWorldSize.y / 2; // Calculate the bottom left position of the grid by starting from the centre (transform.position) and subtracting half the length and height of the grid.
// Cycle through every position of the grid.
for (int y = 0; y < gridSizeY; y++)
{
for (int x = 0; x < gridSizeX; x++)
{
Vector2 worldPoint = bottomLeft + Vector2.right * (x * nodeDiameter + nodeRadius) + Vector2.up * (y * nodeDiameter + nodeRadius); // Calculate position the node is in the world based on position in the grid and node size.
bool walkable = true; // Flag as not being obstructed by default.
// CircleCast at the current position of the grid to check if there are any obstacles, useful for adapting to level design changes.
if (Physics2D.CircleCast(worldPoint, nodeRadius, Vector2.zero, 0.5f, unwalkableMask))
{
walkable = false; // Flag as being obstructed if an obstacle was overalpping the circlecast.
}
// Instantiate node game object and scale to set size.
GameObject _nodeGO = Instantiate(node, worldPoint, Quaternion.identity);
_nodeGO.transform.localScale = Vector3.one * (nodeDiameter - distanceBetweenNodes);
// Assign active algorithms node class to the node game object and store at the current grid position.
switch (PathfinderFactory.ActiveAlgorithm)
{
case PathfinderFactory.Pathfinding.AStar:
AStarNode _aStarNode = _nodeGO.AddComponent <AStarNode>();
_aStarNode.SetValues(walkable, worldPoint, x, y);
grid[x, y] = _aStarNode;
break;
case PathfinderFactory.Pathfinding.Dijkstra:
DijkstraNode _dijkstraNode = _nodeGO.AddComponent <DijkstraNode>();
_dijkstraNode.SetValues(walkable, worldPoint, x, y);
grid[x, y] = _dijkstraNode;
break;
case PathfinderFactory.Pathfinding.BFS:
BFSNode _BFSNode = _nodeGO.AddComponent <BFSNode>();
_BFSNode.SetValues(walkable, worldPoint, x, y);
grid[x, y] = _BFSNode;
break;
case PathfinderFactory.Pathfinding.DFS:
DFSNode _DFSNode = _nodeGO.AddComponent <DFSNode>();
_DFSNode.SetValues(walkable, worldPoint, x, y);
grid[x, y] = _DFSNode;
break;
}
}
}
if (previousObstaclePoints != null) // If any previous obstacles are recorded...
{
// Loop over each, calculate the node that has taken their position and flag them as not walkable.
foreach (Vector2 point in previousObstaclePoints)
{
Node node = NodeFromWorldPoint(point);
node.Walkable = false;
}
}
if (previousStartPosition != Vector2.zero) // If a previous start position exists...
{
// Calculate the node that has taken its position and flag as start node.
Node node = NodeFromWorldPoint(previousStartPosition);
node.IsStartNode = true;
PathfindingManager.instance.startNode = node.transform;
}
if (previousEndPosition != Vector2.zero) // If a previous end position exists...
{
// Calculate the node that has taken its position and flag as end node.
Node node = NodeFromWorldPoint(previousEndPosition);
node.IsEndNode = true;
PathfindingManager.instance.endNode = node.transform;
}
UpdateNodeColours();
}
