// Get outgoing connections from given node
public IEnumerable <IConnection> GetConnections(int fromNode)
{
// Convert node to tile-world position
Vector2Int node = Ind2Vec(fromNode, world.GetLength(0));
// If the position is not blocked, it's a node with possible outgoing
// connections
if (world[node.x, node.y].TileType != TileTypeEnum.Blocked)
{
// Possible destination nodes
Vector2Int up, down, left, right;
// Horizontal world position
int xdim = world.GetLength(0);
// Determine node above
up = node + Vector2Int.up;
// Is node within world limits and unblocked?
if (up.y < world.GetLength(1) &&
world[up.x, up.y].TileType != TileTypeEnum.Blocked)
{
// If so, yield return connection to this node
yield return(new Connection(1f, fromNode, Vec2Ind(up, xdim)));
}
// Determine node below
down = node + Vector2Int.down;
// Is node within world limits and unblocked?
if (down.y >= 0 &&
world[down.x, down.y].TileType != TileTypeEnum.Blocked)
{
// If so, yield return connection to this node
yield return(new Connection(1f, fromNode, Vec2Ind(down, xdim)));
}
// Determine left node
left = node + Vector2Int.left;
// Is node within world limits and unblocked?
if (left.x >= 0 &&
world[left.x, left.y].TileType != TileTypeEnum.Blocked)
{
// If so, yield return connection to this node
yield return(new Connection(1f, fromNode, Vec2Ind(left, xdim)));
}
// Determine right node
right = node + Vector2Int.right;
// Is node within world limits and unblocked?
if (right.x < world.GetLength(0) &&
world[right.x, right.y].TileType != TileTypeEnum.Blocked)
{
// If so, yield return connection to this node
yield return(new Connection(1f, fromNode, Vec2Ind(right, xdim)));
}
}
}
// Euclidean distance heuristic from given node to destination node
private float EuclideanDistance(int node)
{
Vector2 nodeVec = (Vector2)Ind2Vec(node, world.GetLength(0));
Vector2 destVec = (Vector2)GoalPos;
return(Vector2.Distance(nodeVec, destVec));
}
// This method is used as an heuristic for A*
// It's the euclidean distance heuristic
private float HeuristicForAStar(int node)
{
Vector2 nodeVec = (Vector2)Ind2Vec(node, world.GetLength(0));
Vector2 destVec = (Vector2)GoalPos;
return(Vector2.Distance(nodeVec, destVec));
}
/// <summary>
/// Checks if a position is in the bounds of the borad or not
/// </summary>
/// <param name="position"></param>
/// <returns></returns>
public bool IsInBounds(Vector2Int position)
{
if (position.x < 0 || position.x >= board.GetLength(0) || position.y < 0)
{
return(false);
}
return(true);
}