def transform(entities):
for entity in entities:
try:
entity.transform(m)
except NotImplementedError:
skipped_entity_callback(entity, "non transformable")
except NonUniformScalingError:
dxftype = entity.dxftype()
if dxftype in {"ARC", "CIRCLE"}:
if abs(entity.dxf.radius) > ABS_TOL:
yield Ellipse.from_arc(entity).transform(m)
else:
skipped_entity_callback(
entity, f"Invalid radius in entity {str(entity)}.")
elif dxftype in {"LWPOLYLINE", "POLYLINE"}: # has arcs
yield from transform(entity.virtual_entities())
else:
skipped_entity_callback(entity,
"unsupported non-uniform scaling")
except InsertTransformationError:
# INSERT entity can not represented in the target coordinate
# system defined by transformation matrix `m`.
# Yield transformed sub-entities of the INSERT entity:
yield from transform(
virtual_block_reference_entities(entity,
skipped_entity_callback))
else:
yield entity
def test_flattening_by_ellipse(lwpolyline1: LWPolyline):
entities = list(lwpolyline1.virtual_entities())
for e in entities:
if e.dxftype() == "ARC":
ellipse = Ellipse.from_arc(e)
points = list(ellipse.flattening(MAX_SAGITTA))
assert len(points) > 0
def virtual_entities(block_ref: 'Insert') -> Iterable['DXFGraphic']:
"""
Yields 'virtual' entities of block reference `block_ref`. This method is meant to examine the the block reference
entities without the need to explode the block reference.
This entities are located at the 'exploded' positions, but are not stored in the entity database, have no handle
are not assigned to any layout. It is possible to convert this entities into regular drawing entities, this lines
show how to add the virtual `entity` to the entity database and assign this entity to the modelspace::
doc.entitydb.add(entity)
msp = doc.modelspace()
msp.add_entity(entity)
To explode the whole block reference use :meth:`~ezdxf.entities.Insert.explode`.
Args:
block_ref: Block reference entity (:class:`~ezdxf.entities.Insert`)
.. warning::
**Non uniform scaling** returns incorrect results for text entities (TEXT, MTEXT, ATTRIB) and
some other entities like ELLIPSE, SHAPE, HATCH with arc or ellipse path segments and
POLYLINE/LWPOLYLINE with arc segments.
"""
brcs = block_ref.brcs()
# Non uniform scaling will produce incorrect results for some entities!
xscale = block_ref.dxf.xscale
yscale = block_ref.dxf.yscale
uniform_scaling = max(abs(xscale), abs(yscale))
non_uniform_scaling = xscale != yscale
block_layout = block_ref.block()
if block_layout is None:
raise DXFStructureError(
f'Required block definition for "{block_ref.dxf.name}" does not exist.'
)
for entity in block_layout:
dxftype = entity.dxftype()
if dxftype == 'ATTDEF': # do not explode ATTDEF entities
continue
# Copy entity with all DXF attributes
try:
copy = entity.copy()
except DXFTypeError:
continue # non copyable entities will be ignored
if non_uniform_scaling and dxftype in {'ARC', 'CIRCLE'}:
from ezdxf.entities import Ellipse
copy = Ellipse.from_arc(entity)
dxftype = copy.dxftype()
# Basic transformation from BRCS to WCS
try:
copy.transform_to_wcs(brcs)
except NotImplementedError: # entities without 'transform_to_ucs' support will be ignored
continue
# Apply DXF attribute scaling:
# 1. simple entities without properties to scale
if dxftype in {
'LINE', 'POINT', 'LWPOLYLINE', 'POLYLINE', 'MESH', 'HATCH',
'SPLINE', 'SOLID', '3DFACE', 'TRACE', 'IMAGE', 'WIPEOUT',
'XLINE', 'RAY', 'LIGHT', 'HELIX'
}:
pass # nothing else to do
elif dxftype in {'CIRCLE', 'ARC'}:
# simple uniform scaling of radius
# How to handle non uniform scaling? -> Ellipse
copy.dxf.radius = entity.dxf.radius * uniform_scaling
elif dxftype == 'ELLIPSE':
if non_uniform_scaling:
# ELLIPSE -> ELLIPSE
if entity.dxftype() == 'ELLIPSE':
ellipse = cast('Ellipse', entity)
major_axis = Vector(ellipse.dxf.major_axis)
minor_axis = ellipse.minor_axis
major_axis_length = brcs.direction_to_wcs(
major_axis).magnitude
minor_axis_length = brcs.direction_to_wcs(
minor_axis).magnitude
copy.dxf.ratio = max(minor_axis_length / major_axis_length,
1e-6)
else: # ARC -> ELLIPSE
scale = max(min((yscale / xscale), 1.0), 1e-6)
copy.dxf.ratio = scale
elif dxftype == 'MTEXT':
# Scale MTEXT height/width just by uniform_scaling, how to handle non uniform scaling?
copy.dxf.char_height *= uniform_scaling
copy.dxf.width *= uniform_scaling
elif dxftype in {'TEXT', 'ATTRIB'}:
# Scale TEXT height just by uniform_scaling, how to handle non uniform scaling?
copy.dxf.height *= uniform_scaling
elif dxftype == 'INSERT':
# Set scaling of child INSERT to scaling of parent INSERT
for scale in ('xscale', 'yscale', 'zscale'):
if block_ref.dxf.hasattr(scale):
original_scale = copy.dxf.get_default(scale)
block_ref_scale = block_ref.dxf.get(scale)
copy.dxf.set(scale, original_scale * block_ref_scale)
if uniform_scaling != 1:
# Scale attached ATTRIB entities:
# Scale height just by uniform_scaling, how to handle non uniform scaling?
for attrib in copy.attribs:
attrib.dxf.height *= uniform_scaling
elif dxftype == 'SHAPE':
# Scale SHAPE size just by uniform_scaling, how to handle non uniform scaling?
copy.dxf.size *= uniform_scaling
else: # unsupported entity will be ignored
continue
yield copy
