WIDTH = 480
HEIGHT = 480

rows = [WIDTH * 0.0, WIDTH * 0.25, WIDTH * 0.50, WIDTH * 0.75, WIDTH * 1.00]
columns = [HEIGHT * 0.0, HEIGHT * 0.25, HEIGHT * 0.50, HEIGHT * 0.75, HEIGHT * 1.00]
coordinates = [(i, j) for i in rows for j in columns]

# "coordinates" is a list of tuples of all the vertices:
# [(0.0, 0.0), (0.0, 120.0), (0.0, 240.0), (0.0, 360.0), (0.0, 480.0), (120.0, 0.0), (120.0, 120.0), (120.0, 240.0), (120.0, 360.0), (120.0, 480.0), ...]