hex-spiral is library for working with 2D hexagonal maps using single-coordinate positions.
While most hex-grid-based 2D games use multiple coordinates, hex-spiral uses a single-coordinate spiral,
where the central hex has the position 0, and further hexes are placed within theoretical hexagonal rings
that surround it.
- add conversion from hex position to window/screen coordinates
- add conversion from window/screen coordinates to hex position
- revise the APIs and data types