def test_tangents():
e = ConstructionEllipse(center=(3, 3),
major_axis=(2, 0),
ratio=0.5,
start_param=0,
end_param=math.pi * 1.5)
params = list(e.params(7))
result = [(0.0, 1.0, 0.0), (-0.894427190999916, 0.447213595499958, 0.0),
(-1.0, 3.061616997868383e-17, 0.0),
(-0.894427190999916, -0.4472135954999579, 0.0),
(-2.4492935982947064e-16, -1.0, 0.0),
(0.8944271909999159, -0.44721359549995804, 0.0), (1.0, 0.0, 0.0)]
for v, r in zip(e.tangents(params), result):
assert v.isclose(r)
def test_vertices():
e = ConstructionEllipse(center=(3, 3), major_axis=(2, 0), ratio=0.5, start_param=0, end_param=math.pi * 1.5)
params = list(e.params(7))
result = [
(5.0, 3.0, 0.0),
(4.414213562373095, 3.7071067811865475, 0.0),
(3.0, 4.0, 0.0),
(1.585786437626905, 3.7071067811865475, 0.0),
(1.0, 3.0, 0.0),
(1.5857864376269046, 2.2928932188134525, 0.0),
(3.0, 2.0, 0.0),
]
for v, r in zip(e.vertices(params), result):
assert v.isclose(r)
v1, v2 = e.vertices([0, math.tau])
assert v1 == v2
def to_line_edges(edge):
# Start- and end params are always stored in counter clockwise order!
ellipse = ConstructionEllipse(
center=edge.center,
major_axis=edge.major_axis,
ratio=edge.ratio,
start_param=edge.start_param,
end_param=edge.end_param,
)
segment_count = max(
int(float(num) * ellipse.param_span / math.tau), 3
)
params = ellipse.params(segment_count + 1)
# Reverse path if necessary!
if not edge.ccw:
params = reversed(list(params))
vertices = list(ellipse.vertices(params))
for v1, v2 in zip(vertices[:-1], vertices[1:]):
line = LineEdge()
line.start = v1.vec2
line.end = v2.vec2
yield line
def test_params():
count = 9
e = ConstructionEllipse(start_param=math.pi / 2, end_param=-math.pi / 2)
params = list(e.params(count))
expected = list(linspace(math.pi / 2, math.pi / 2.0 * 3.0, count))
assert params == expected
