public override void nextTile()
{
if (ctX == ntX - 1 && ctY == ntY - 1)
{
// Already at last tile
throw new NoNextElementException();
}
else if (ctX < ntX - 1)
{
// If not at end of current tile line
setTile(ctX + 1, ctY);
}
else
{
// Go to first tile at next line
setTile(0, ctY + 1);
}
}