/// <summary>
/// 2016-2-22
/// Returns all the neighbors of the provided coordinates. Optional last parameter indicates the
/// neighbor filter:
/// 0 -- return all neighbors
/// 1 -- return orthogonal neighbors only
/// 2 -- diagonal neighbors only
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="source"></param>
/// <param name="x"></param>
/// <param name="y"></param>
/// <returns></returns>
public static List <T> GetNeighborsOf <T>(this T[,,] source, int x, int y, int z, int filter = 0)
{
if (!source.ContainsCoords(x, y, z))
{
return(null);
}
List <T> neighbors = new List <T>();
for (int i = -1; i <= 1; i++)
{
for (int j = -1; j <= 1; j++)
{
for (int k = -1; k <= 1; k++)
{
int indexX = x + i;
int indexY = y + j;
int indexZ = z + k;
// ignore coordinates that aren't on the map
if (!source.ContainsCoords(indexX, indexY, indexZ))
{
continue;
}
// ignore the center coordinate
if (i == 0 && j == 0 && k == 0)
{
continue;
}
switch (filter)
{
case 1:
// skip diagonals
if ((i == -1 || i == 1) && j != 0 && k != 0)
{
continue;
}
if ((j == -1 || j == 1) && i != 0 && k != 0)
{
continue;
}
if ((k == -1 || k == 1) && i != 0 && j != 0)
{
continue;
}
break;
case 2:
// skip orthogonals
if ((i == -1 || i == 1) && j == 0 && k == 0)
{
continue;
}
if ((j == -1 || j == 1) && i == 0 && k == 0)
{
continue;
}
if ((k == -1 || k == 1) && i == 0 && j == 0)
{
continue;
}
break;
case 0:
default:
// keep everything
break;
}
neighbors.Add(source[indexX, indexY, indexZ]);
}
}
}
return(neighbors);
}