def transform(self, m: "Matrix44") -> "LWPolyline":
"""Transform the LWPOLYLINE entity by transformation matrix `m` inplace.
A non uniform scaling is not supported if the entity contains circular
arc segments (bulges).
Args:
m: transformation :class:`~ezdxf.math.Matrix44`
Raises:
NonUniformScalingError: for non uniform scaling of entity containing
circular arc segments (bulges)
"""
dxf = self.dxf
ocs = OCSTransform(self.dxf.extrusion, m)
if not ocs.scale_uniform and self.has_arc:
raise NonUniformScalingError(
"LWPOLYLINE containing arcs (bulges) does not support non uniform scaling"
)
# The caller function has to catch this exception and explode the
# LWPOLYLINE into LINE and ELLIPSE entities.
vertices = list(
ocs.transform_vertex(v) for v in self.vertices_in_ocs())
lwpoints = []
for v, p in zip(vertices, self.lwpoints):
_, _, start_width, end_width, bulge = p
# assume a uniform scaling!
start_width = ocs.transform_width(start_width)
end_width = ocs.transform_width(end_width)
lwpoints.append((v.x, v.y, start_width, end_width, bulge))
self.set_points(lwpoints)
# All new OCS vertices must have the same z-axis, which is the elevation
# of the polyline:
if vertices:
dxf.elevation = vertices[0].z
if dxf.hasattr("const_width"): # assume a uniform scaling!
dxf.const_width = ocs.transform_width(dxf.const_width)
if dxf.hasattr("thickness"):
dxf.thickness = ocs.transform_thickness(dxf.thickness)
dxf.extrusion = ocs.new_extrusion
self.post_transform(m)
return self
def test_x_scaling(self, width):
ocs = OCSTransform(Z_AXIS, Matrix44.scale(2, 1, 1))
assert ocs.transform_width(width) == pytest.approx(
2 * abs(width)
), "current implementation scales by biggest x- or y-axis factor"
def test_uniform_scaling_for_all_axis(self, width):
ocs = OCSTransform(Z_AXIS, Matrix44.scale(-2, -2, -2))
assert ocs.transform_width(width) == pytest.approx(
2 * abs(width)
), "width should always be >= 0"
def test_no_transformation(self, width):
ocs = OCSTransform(Z_AXIS, Matrix44())
assert ocs.transform_width(width) == pytest.approx(abs(width))
def test_non_uniform_xy_scaling_for_y(self, width):
ocs = OCSTransform(Z_AXIS, Matrix44.scale(-2, -3, 1))
assert ocs.transform_width(width) == pytest.approx(
3 * abs(width)
), "current implementation scales by biggest x- or y-axis factor"
def transform(self, m: Matrix44) -> "Polyline":
"""Transform the POLYLINE entity by transformation matrix `m` inplace.
A non uniform scaling is not supported if a 2D POLYLINE contains
circular arc segments (bulges).
Args:
m: transformation :class:`~ezdxf.math.Matrix44`
Raises:
NonUniformScalingError: for non uniform scaling of 2D POLYLINE
containing circular arc segments (bulges)
"""
def _ocs_locations(elevation):
for vertex in self.vertices:
location = vertex.dxf.location
if elevation is not None:
# Older DXF versions may not have written the z-axis, so
# replace existing z-axis by the elevation value.
location = location.replace(z=elevation)
yield location
if self.is_2d_polyline:
dxf = self.dxf
ocs = OCSTransform(self.dxf.extrusion, m)
if not ocs.scale_uniform and self.has_arc:
raise NonUniformScalingError(
"2D POLYLINE containing arcs (bulges) does not support non uniform scaling"
)
# The caller function has to catch this exception and explode the
# 2D POLYLINE into LINE and ELLIPSE entities.
if dxf.hasattr("elevation"):
z_axis = dxf.elevation.z
else:
z_axis = None
vertices = [
ocs.transform_vertex(vertex)
for vertex in _ocs_locations(z_axis)
]
# All vertices of a 2D polyline must have the same z-axis, which is
# the elevation of the polyline:
if vertices:
dxf.elevation = vertices[0].replace(x=0, y=0)
for vertex, location in zip(self.vertices, vertices):
vdxf = vertex.dxf
vdxf.location = location
if vdxf.hasattr("start_width"):
vdxf.start_width = ocs.transform_width(vdxf.start_width)
if vdxf.hasattr("end_width"):
vdxf.end_width = ocs.transform_width(vdxf.end_width)
if dxf.hasattr("default_start_width"):
dxf.default_start_width = ocs.transform_width(
dxf.default_start_width)
if dxf.hasattr("default_end_width"):
dxf.default_end_width = ocs.transform_width(
dxf.default_end_width)
if dxf.hasattr("thickness"):
dxf.thickness = ocs.transform_thickness(dxf.thickness)
dxf.extrusion = ocs.new_extrusion
else:
for vertex in self.vertices:
vertex.transform(m)
self.post_transform(m)
return self
