Discrete Grid Spiral Iterator

spiral_iterator.py

def square_iterator(x: int, y: int):
    """Generate all the points on a square 2d lattice, spiraling out from the center.  Modified from a solution by Nikita Rybak. https://stackoverflow.com/a/3706260"""
    dx = 1
    dy = 0
    segment_length = 1
    leg_iterations = 0

    while True:
        x += dx
        y += dy
        yield((x, y))
        leg_iterations += 1
        if leg_iterations >= segment_length:
            leg_iterations = 0
            # Rotate our direction by 90 degrees, and when we're back to dx == 0 (on the flat side), bump the segment_length by 1.
            tmp = dy
            dy = -dx
            dx = tmp

            if dy == 0:
                segment_length += 1