def aa_rect_overlaps_aa_rect(aa_rect, other):
    """
    Tells if two axis aligned rectangles overlap.

    The rects must have members 'center', 'rx', 'ry' where the latest two are
    the rect half_width and half_height.
    """
    return abs(aa_rect.center[0] - other.center[0]
        ) < aa_rect.rx + other.rx and abs(aa_rect.center[1] - other.center[1]
        ) < aa_rect.ry + other.ry
