def test_point_on_line():
line = LineSegment(Point(0, 0), Point(4, 4))
a = Point(3, 3)
assert not is_point_right_of_line(line, a)
line = LineSegment(Point(4, 4), Point(0, 0))
assert not is_point_right_of_line(line, a)
def test_lines_do_intersect_t6():
for _ in range(50):
ax = random.random()
ay = random.random()
bx = random.random()
by = random.random()
a = LineSegment(Point(ax, ay), Point(bx, by))
b = LineSegment(Point(ax, ay), Point(bx, by))
assert do_lines_intersect(a, b)
def test_antisymmetry_of_cross_product():
points = [Point(0, 0), Point(1, 1)]
for _ in range(50):
points.append(Point(random.random(), random.random()))
for p1 in points:
for p2 in points:
r1 = crossproduct(p1, p2)
r2 = crossproduct(p2, p1)
assert abs(r1 + r2) < EPSILON, f"[{p1}, {p2}]"
def get_shortest_endpoint(x, y,
intersections: List[Point]) -> Tuple[float, float]:
shortest_x, shortest_y = intersections[0].x, intersections[0].y
min_length = LineSegment(Point(x, y), Point(shortest_x,
shortest_y)).length()
for p in intersections:
xe, ye = p.x, p.y
tmp = LineSegment(Point(x, y), Point(xe, ye))
if tmp.length() < min_length:
shortest_x = xe
shortest_y = ye
return (shortest_x, shortest_y)
def test_compare_to_brute_force():
n = 30
max_intersections = (n * n - n) / 2
lines: List[LineSegment] = []
for _ in range(n):
a = Point(random.random(), random.random())
b = Point(random.random(), random.random())
lines.append(LineSegment(a, b))
intersectionsBrute: Set[
LineSegment] = get_all_intersecting_lines_by_brute_force(lines)
# intersectionsSweep: Set[LineSegment] = getAllIntersectingLines(lines)
assert len(intersectionsBrute) <= max_intersections
def get_intersections(
line: Tuple[int, int, float, float],
lines: List[Tuple[int, int, int, int]]) -> List[Tuple[float, float]]:
(x, y, xe, ye) = line
line_segment = LineSegment(Point(x, y), Point(xe, ye))
intersections = []
for line_tmp in lines:
x1, y1, x2, y2 = line_tmp
line_segment_tmp = LineSegment(Point(x1, y1), Point(x2, y2))
intersection = line_segment.get_intersection(line_segment_tmp)
if intersection is not None:
intersections.append(intersection)
return intersections
def test_line_segment_crosses_line():
"""Tests for lineSegmentCrossesLine"""
line_segment = LineSegment(Point(5, 5), Point(17, 17))
line = LineSegment(Point(0, 0), Point(1, 1))
assert line_segment_touches_or_crosses_line(line_segment, line)
line_segment = LineSegment(Point(17, 17), Point(5, 5))
line = LineSegment(Point(0, 0), Point(1, 1))
assert line_segment_touches_or_crosses_line(line_segment, line)
def test_line_segment_equality():
line_segment1 = LineSegment(Point(0, 0), Point(42, 0))
line_segment2 = LineSegment(Point(42, 0), Point(0, 0))
assert line_segment1 == line_segment2
line_segment1 = LineSegment(Point(0, 0), Point(42.1, 0))
line_segment2 = LineSegment(Point(42, 0), Point(0, 0))
assert line_segment1 != line_segment2
assert line_segment1 != "[(0|0), (42|0)]"
def test_line_segment_point_intersection_up_down():
"""A single point intersection"""
ls1 = LineSegment(Point(0, -4), Point(0, 4))
ls2 = LineSegment(Point(0, 2), Point(0, -2))
expected = LineSegment(Point(0, -2), Point(0, 2))
assert ls1.intersect(ls2).simplify() == expected
assert ls2.intersect(ls1).simplify() == expected
def test_get_equation_parameters():
line_segment = LineSegment(Point(0, 0), Point(1, 0))
assert line_segment._get_equation_parameters() == (0, 0)
line_segment = LineSegment(Point(0, 0), Point(1, 1))
assert line_segment._get_equation_parameters() == (1, 0)
line_segment = LineSegment(Point(0, 0), Point(0, 1))
with pytest.raises(ValueError) as exinfo:
line_segment._get_equation_parameters()
assert str(exinfo.value) == "The given points have the same x-coordinate"
def create(width: int = 1400,
height: int = 1200,
nb_points: int = 100,
max_length: int = None,
iterations: int = 10):
if max_length is None:
max_length = int((width**2 + height**2)**0.5)
lines: List[Tuple[int, int, int, int]] = []
points = [(
random.randint(0, width),
random.randint(0, height),
math.radians(random.randint(0, 360)),
) for _ in range(nb_points)]
for _ in progressbar.progressbar(range(iterations)):
new_points: List[Tuple[int, int, float]] = []
for point in points:
x, y, angle = point
# Find end
dx, dy = math.cos(angle), math.sin(angle)
xe, ye = x + dx * max_length, y + dy * max_length
xe, ye = crop_at_box((x, y, xe, ye), width, height)
# Get all intersections
intersections = get_intersections(
(x, y, xe, ye), lines) + [Point(xe, ye)]
# And use the first intersection
xe, ye = get_shortest_endpoint(x, y, intersections)
xe, ye = int(xe), int(ye)
lines.append((x, y, xe, ye))
new_points.append(
(xe, ye, math.radians((math.degrees(angle) + 90) % 360)))
# draw
img_size = (height, width)
img = np.ones(img_size) * 255
lineThickness = 2
for x1, y1, x2, y2 in lines:
cv2.line(img, (x1, y1), (x2, y2), (0, 255, 0), lineThickness)
cv2.imwrite("houghlines3.jpg", img)
def test_lines_dont_intersect_f2():
a = LineSegment(Point(-4, 4), Point(-2, 1))
b = LineSegment(Point(-2, 3), Point(0, 0))
assert not do_lines_intersect(a, b)
def test_line_segment_simplify_self():
line_segment1 = LineSegment(Point(0, 0), Point(42, 0))
assert str(line_segment1.simplify()) == "LineSegment [(0|0) to (42|0)]"
def test_point_equality():
p1 = Point(0, 0)
assert not (p1 == "(0|0)")
p2 = Point(0.0, 0.0)
assert p1 == p2
def test_point_str():
p1 = Point(0, 0)
assert str(p1) == "(0|0)"
assert repr(p1) == "(0|0)"
def test_lines_dont_intersect_f8():
a = LineSegment(Point(0, 5), Point(6, 0))
b = LineSegment(Point(2, 1), Point(2, 2))
assert not do_lines_intersect(a, b)
def test_lines_dont_intersect_f1():
"""Tests for do_lines_intersect"""
a = LineSegment(Point(0, 0), Point(7, 7))
b = LineSegment(Point(3, 4), Point(4, 5))
assert not do_lines_intersect(a, b)
def test_line_segment_intersection_90_270():
"""A single point intersection"""
ls1 = LineSegment(Point(0, 0), Point(0, 1))
ls2 = LineSegment(Point(0, 3), Point(0, 1))
assert ls1.intersect(ls2) == Point(0, 1)
assert ls2.intersect(ls1) == Point(0, 1)
def test_lines_dont_intersect_f5():
a = LineSegment(Point(-1, -1), Point(2, 2))
b = LineSegment(Point(3, 3), Point(5, 5))
assert not do_lines_intersect(a, b)
def test_lines_do_intersect_t4():
a = LineSegment(Point(0, 2), Point(2, 2))
b = LineSegment(Point(2, 0), Point(2, 4))
assert do_lines_intersect(a, b)
def test_lines_do_intersect_t3():
a = LineSegment(Point(-1, 0), Point(0, 0))
b = LineSegment(Point(-1, -1), Point(-1, 1))
assert do_lines_intersect(a, b)
def test_lines_dont_intersect_f6():
a = LineSegment(Point(0, 0), Point(1, 1))
b = LineSegment(Point(2, 0), Point(0.5, 2))
assert not do_lines_intersect(a, b)
def test_lines_do_intersect_t2():
a = LineSegment(Point(5, 5), Point(0, 0))
b = LineSegment(Point(1, 1), Point(8, 2))
assert do_lines_intersect(a, b)
def test_line_segment_no_intersection1():
"""No intersection"""
ls1 = LineSegment(Point(0, 0), Point(1, 0))
ls2 = LineSegment(Point(2, 0), Point(3, 0))
assert ls1.intersect(ls2) is None
assert ls2.intersect(ls1) is None
def test_line_segment_no_intersection2():
"""No intersection"""
ls1 = LineSegment(Point(0, 0), Point(0, 1))
ls2 = LineSegment(Point(0, 2), Point(0, 3))
assert ls1.intersect(ls2) is None
assert ls2.intersect(ls1) is None
def test_blog_example():
"""check getAllIntersectingLines()"""
lines: List[LineSegment] = [
LineSegment(Point(1, 4), Point(6, 1), "a"),
LineSegment(Point(2, 1), Point(5, 4), "b"),
LineSegment(Point(3, 1), Point(6, 4), "c"),
LineSegment(Point(4, 1), Point(8, 5), "d"),
LineSegment(Point(3, 4), Point(9, 3), "e"),
LineSegment(Point(7, 2), Point(9, 3), "f"),
LineSegment(Point(6, 7), Point(9, 1), "g"),
LineSegment(Point(11, 1), Point(16, 5), "h"),
LineSegment(Point(13, 3), Point(13, 4), "i"),
LineSegment(Point(15, 3), Point(15, 4), "j"),
LineSegment(Point(13, 2), Point(14, 2), "k"),
LineSegment(Point(14, 1), Point(14, 2), "l"),
LineSegment(Point(17, 3), Point(21, 3), "m"),
LineSegment(Point(19, 5), Point(19, 1), "n"),
LineSegment(Point(11, 1), Point(16, 5), "o"),
]
intersections: Set[LineSegment] = set()
add = frozenset({lines[0], lines[1]})
intersections.add(add)
add = frozenset({lines[0], lines[2]})
intersections.add(add)
add = frozenset({lines[0], lines[3]})
intersections.add(add)
add = frozenset({lines[3], lines[6]})
intersections.add(add)
add = frozenset({lines[4], lines[1]})
intersections.add(add)
add = frozenset({lines[4], lines[2]})
intersections.add(add)
add = frozenset({lines[4], lines[3]})
intersections.add(add)
add = frozenset({lines[4], lines[5]})
intersections.add(add)
add = frozenset({lines[4], lines[6]})
intersections.add(add)
add = frozenset({lines[5], lines[6]})
intersections.add(add)
add = frozenset({lines[10], lines[11]})
intersections.add(add)
add = frozenset({lines[12], lines[13]})
intersections.add(add)
add = frozenset({lines[7], lines[14]})
intersections.add(add)
intersectionsBrute: Set[
LineSegment] = get_all_intersecting_lines_by_brute_force(lines)
# intersectionsSweep: Set[LineSegment] = getAllIntersectingLines(lines)
assert intersectionsBrute == intersections
def test_lines_dont_intersect_f3():
a = LineSegment(Point(0, 0), Point(0, 1))
b = LineSegment(Point(2, 2), Point(2, 3))
assert not do_lines_intersect(a, b)
def test_get_straight_line_intersection():
intersection = _get_straight_line_intersection(0, 0, 10, 5, 20)
assert intersection == LineSegment(Point(0, 5), Point(0, 10))
def test_lines_do_intersect_t5():
a = LineSegment(Point(0, 0), Point(5, 5))
b = LineSegment(Point(1, 1), Point(3, 3))
assert do_lines_intersect(a, b)
def test_lines_dont_intersect_f7():
a = LineSegment(Point(1, 1), Point(4, 1))
b = LineSegment(Point(2, 2), Point(3, 2))
assert not do_lines_intersect(a, b)
