public IEnumerable <HexCoords> Arc(uint radius, HexFacing begin, HexFacing end)
{
HexCoords cursor = this + (begin.ToOffset() * (int)radius);
// Yielding the initial cursor position is unique to arcs,
// and is why this code works at radius 0 while rings do not.
yield return(cursor);
// We need to track our travel facing.
// When following a circle, we start at the southwest corner heading north.
// Southwest to north is rotating CW twice.
// Any corner you start at, your travel on that side will be CW twice.
HexRotation turnIntoSide = new HexRotation(2);
foreach (HexFacing facing in begin.Rotate(2).CompassTurnCW(end.Rotate(1)))
{
for (int idx = 0; idx < radius; idx++)
{
cursor += facing;
yield return(cursor);
}
}
}
