def main():
doc = ezdxf.new()
doc.layers.add(ENTITIES, color=colors.YELLOW)
doc.layers.add(INTERSECTION_POINTS, color=colors.RED)
doc.layers.add(CURVE_APPROXIMATIONS, color=colors.CYAN)
msp = doc.modelspace()
ellipse = msp.add_ellipse(
center=(0, 0),
major_axis=(3, 0),
ratio=0.5,
dxfattribs=GfxAttribs(layer=ENTITIES),
)
fit_points = [(-4, -4), (-2, -1), (2, 1), (4, 4)]
spline = msp.add_spline_control_frame(
fit_points, dxfattribs=GfxAttribs(layer=ENTITIES)
)
p1 = Vec2.list(ellipse.flattening(distance=0.001))
p2 = Vec2.list(spline.flattening(distance=0.001))
msp.add_lwpolyline(p1, dxfattribs=GfxAttribs(layer=CURVE_APPROXIMATIONS))
msp.add_lwpolyline(p2, dxfattribs=GfxAttribs(layer=CURVE_APPROXIMATIONS))
res = intersect_polylines_2d(p1, p2)
for point in res:
msp.add_circle(
center=point,
radius=0.1,
dxfattribs=GfxAttribs(layer=INTERSECTION_POINTS),
)
doc.set_modelspace_vport(height=10)
doc.saveas(DIR / "intersect_ellipse_and_spline.dxf")
def test_complex_ellipse_with_spline_intersection(self):
ellipse = ConstructionEllipse(center=(0, 0), major_axis=(3, 0), ratio=0.5)
bspline = BSpline([(-4, -4), (-2, -1), (2, 1), (4, 4)])
p1 = ellipse.flattening(distance=0.01)
p2 = bspline.flattening(distance=0.01)
res = intersect_polylines_2d(Vec2.list(p1), Vec2.list(p2))
assert len(res) == 2
def test_coincident_common_segment(self):
""" The common segment does not create intersection points.
Same as intersection of coincident lines!
"""
pline1 = Vec2.list([(1, 1), (2, 1)])
pline2 = Vec2.list([(1, 1), (2, 1)])
res = intersect_polylines_2d(pline1, pline2)
assert len(res) == 0
def test_intersecting_squares(self):
square1 = forms.close_polygon(forms.square(2.0))
square2 = forms.translate(square1, (1, 1))
res = intersect_polylines_2d(Vec2.list(square1), Vec2.list(square2))
assert len(res) == 2
res.sort()
assert res[0].isclose(Vec2(1, 2))
assert res[1].isclose(Vec2(2, 1))
def test_zig_zag_lines_with_common_vertices(self):
pline1 = Vec2.list([(0, 0), (2, 2), (4, 0), (6, 2), (8, 0)])
pline2 = Vec2.list([(0, 4), (2, 2), (4, 4), (6, 2), (8, 4)])
res = intersect_polylines_2d(pline1, pline2)
assert len(res) == 2
res.sort() # do not rely on any order
assert res[0].isclose(Vec2(2, 2))
assert res[1].isclose(Vec2(6, 2))
def test_coincident_common_last_segment(self):
""" The common segment does not create intersection points, but the
preceding segment does.
"""
pline1 = Vec2.list([(0, 0), (1, 1), (2, 1)])
pline2 = Vec2.list([(0, 2), (1, 1), (2, 1)])
res = intersect_polylines_2d(pline1, pline2)
assert len(res) == 1
assert res[0].isclose(Vec2(1, 1))
def test_intersecting_zig_zag_lines(self):
pline1 = Vec2.list([(0, 0), (2, 2), (4, 0), (6, 2), (8, 0)])
pline2 = Vec2.list([(0, 2), (2, 0), (4, 2), (6, 0), (8, 2)])
res = intersect_polylines_2d(pline1, pline2)
assert len(res) == 4
res.sort() # do not rely on any order
assert res[0].isclose(Vec2(1, 1))
assert res[1].isclose(Vec2(3, 1))
assert res[2].isclose(Vec2(5, 1))
assert res[3].isclose(Vec2(7, 1))
def test_coincident_common_intermediate_segment(self):
""" The common segment does not create intersection points, but the
preceding and the following segment does.
"""
pline1 = Vec2.list([(0, 0), (1, 1), (2, 1), (3, 0)])
pline2 = Vec2.list([(0, 2), (1, 1), (2, 1), (3, 2)])
res = intersect_polylines_2d(pline1, pline2)
assert len(res) == 2
res.sort()
assert res[0].isclose(Vec2(1, 1))
assert res[1].isclose(Vec2(2, 1))
def test_squares_with_common_corner_vertex(self):
square1 = forms.close_polygon(forms.square(2.0))
square2 = forms.translate(square1, (2, 2))
res = intersect_polylines_2d(Vec2.list(square1), Vec2.list(square2))
assert len(res) == 1
assert res[0].isclose(Vec2(2, 2))
def test_intersecting_x_cross(self):
pline1 = Vec2.list([(0, 0), (1, 1), (2, 2)])
pline2 = Vec2.list([(2, 0), (1, 1), (0, 2)])
res = intersect_polylines_2d(pline1, pline2)
assert len(res) == 1
assert res[0].isclose(Vec2(1, 1))
def test_none_intersecting_single_segments(self):
pline1 = Vec2.list([(0, 0), (2, 0)])
pline2 = Vec2.list([(0, 1), (2, 1)])
res = intersect_polylines_2d(pline1, pline2)
assert len(res) == 0
def test_intersecting_single_segments(self):
pline1 = Vec2.list([(0, 1), (2, 1)])
pline2 = Vec2.list([(1, 0), (1, 2)])
res = intersect_polylines_2d(pline1, pline2)
assert len(res) == 1
assert res[0].isclose(Vec2(1, 1))