test_bresenham.py

import pytest

from bresenham import bresenham


@pytest.mark.parametrize(('x0', 'y0', 'x1', 'y1', 'result'), (
    (0, 0, 0, 0, ((0, 0), )),
    (0, 0, 5, 0, ((0, 0), (1, 0), (2, 0), (3, 0), (4, 0), (5, 0))),
    (0, 0, -5, 0, ((0, 0), (-1, 0), (-2, 0), (-3, 0), (-4, 0), (-5, 0))),
    (0, 0, 0, 5, ((0, 0), (0, 1), (0, 2), (0, 3), (0, 4), (0, 5))),
    (0, 0, 0, -5, ((0, 0), (0, -1), (0, -2), (0, -3), (0, -4), (0, -5))),
    (0, 0, 2, 3, ((0, 0), (1, 1), (1, 2), (2, 3))),
    (0, 0, -2, 3, ((0, 0), (-1, 1), (-1, 2), (-2, 3))),
    (0, 0, 2, -3, ((0, 0), (1, -1), (1, -2), (2, -3))),
    (0, 0, -2, -3, ((0, 0), (-1, -1), (-1, -2), (-2, -3))),
    (-1, -3, 3, 3, ((-1, -3), (0, -2), (0, -1),
                    (1, 0), (2, 1), (2, 2), (3, 3))),
    (0, 0, 11, 1, ((0, 0), (1, 0), (2, 0), (3, 0), (4, 0), (5, 0),
                   (6, 1), (7, 1), (8, 1), (9, 1), (10, 1), (11, 1))),
))
def test_bresenham(x0, y0, x1, y1, result):
    assert tuple(bresenham(x0, y0, x1, y1)) == result
    assert tuple(bresenham(x1, y1, x0, y0)) == tuple(reversed(result))


def test_min_slope_two_way():
    assert tuple(bresenham(0, 0, 10, 1)) == ((0, 0), (1, 0), (2, 0), (3, 0),
                                             (4, 0), (5, 1), (6, 1), (7, 1),
                                             (8, 1), (9, 1), (10, 1))
    assert tuple(bresenham(10, 1, 0, 0)) == ((10, 1), (9, 1), (8, 1), (7, 1),
                                             (6, 1), (5, 0), (4, 0), (3, 0),
                                             (2, 0), (1, 0), (0, 0))