def test_params_from_vertices_random():
center = Vector.random(5)
major_axis = Vector.random(5)
extrusion = Vector.random()
ratio = 0.75
e = ConstructionEllipse(center, major_axis, extrusion, ratio)
params = [random.uniform(0.0001, math.tau - 0.0001) for _ in range(20)]
vertices = e.vertices(params)
new_params = e.params_from_vertices(vertices)
for expected, param in zip(params, new_params):
assert math.isclose(expected, param)
# This creates the same vertex as v1 and v2
v1, v2 = e.vertices([0, math.tau])
assert v1.isclose(v2)
# This should create the same param for v1 and v2, but
# floating point inaccuracy produces unpredictable results:
p1, p2 = e.params_from_vertices((v1, v2))
assert math.isclose(p1, 0, abs_tol=1e-9) or math.isclose(
p1, math.tau, abs_tol=1e-9)
assert math.isclose(p2, 0, abs_tol=1e-9) or math.isclose(
p2, math.tau, abs_tol=1e-9)
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 test_get_start_and_end_vertex():
ellipse = ConstructionEllipse(
center=(1, 2, 3),
major_axis=(4, 3, 0),
extrusion=(0, 0, -1),
ratio=.7,
start_param=math.pi / 2,
end_param=math.pi,
)
start, end = list(ellipse.vertices([
ellipse.start_param,
ellipse.end_param,
]))
# test values from BricsCAD
assert start.isclose(Vec3(3.1, -0.8, 3), abs_tol=1e-6)
assert end.isclose(Vec3(-3, -1, 3), abs_tol=1e-6)
# for convenience, but vertices() is much more efficient:
assert ellipse.start_point.isclose(Vec3(3.1, -0.8, 3), abs_tol=1e-6)
assert ellipse.end_point.isclose(Vec3(-3, -1, 3), abs_tol=1e-6)
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
