//
// use to add he eight neighboring edges of a graph node that
// is positioned in a grid layout
public static void AddAllNeighboursToGridNode(NavGraph graph, int row, int col, int numCellsX, int numCellsY)
{
for (int i = -1; i <= +1; ++i)
{
for (int j = -1; j <= +1; ++j)
{
//skip if equal to this node
if (i == 0 && j == 0)
{
continue;
}
int nodeX = col + j;
int nodeY = row + i;
//check to see if this is a valid neighbour
if (ValidNeighbour(nodeX, nodeY, numCellsX, numCellsY))
{
//calculate the distance to this node
Vector2 posNode = graph.GetNode(row * numCellsX + col).Position;
Vector2 posNeighbour = graph.GetNode(nodeY * numCellsX + nodeX).Position;
float dist = Vector2.Length(posNeighbour - posNode);
GraphEdge newEdge;
newEdge = new GraphEdge(row * numCellsX + col, nodeY * numCellsX + nodeX, dist);
graph.AddEdge(newEdge);
//if graph is not a diagraph then an edge needs to be added going
//in the other direction
if (!graph.IsDigraph())
{
newEdge = new GraphEdge(nodeY * numCellsX + nodeX, row * numCellsX + col, dist);
graph.AddEdge(newEdge);
}
}
}
}
}