/// <summary>
/// Take world coodinates and find the corresponding square. The
/// result is returned as an int array that contains that square's
/// position in the matrix.
/// </summary>
private static int[] GetSquare(Vector3 vec)
{
const CoordinateSystem system = CoordinateSystem.Grid;
var cell = _grid.NearestCell(vec, system);
var shift = .5f * Vector3.one;
var square = cell - shift;
var indices = new int[2];
for (var i = 0; i < 2; ++i)
{
// Remember, boxes don't have whole coordinates, that's why we
// use a little shift to turn e.g. (3.5, 2.5, 1.5) into (3, 2,
// 1).
indices[i] = Mathf.RoundToInt(square[i]);
}
return(indices);
}