linkcad.edit

Geometry manipulation tasks. Each task is constructed against a Drawing (or, for FlattenTask, a Cell) and is run by calling task.execute(). Tasks must be run inside a WriteLock (standalone scripts) or a Transaction (tool plugins).

from linkcad.v1.edit import (
    ITask,
    SnapToGridTask,
    FlattenTask,
    RemoveDuplicatesTask,
    MergeTask,
    ClosePolylinesTask,
    JoinPolylinesTask,
    PolylineToPolygonTask,
    ExplodeToPolygonTask,
    RemoveZeroWidthPolylinesTask,
    RemoveOverlappingPolylinesTask,
    FixSelfIntersectingPolygonsTask,
    FillRule,
    HolesMode,
    EdgePolicy,
    PolygonSnapMode,
    ShapesToConvert,
    CellFilter,
    LayerFilter,
    ShapeFilter,
)

Base Class

ITask

All tasks extend ITask.

Property / Method	Description
task.execute()	Run the task. May raise on failure
task.cancel()	Cancel a running task
task.progress	Progress percentage (0-100)
task.cell_filter	Which cells the task processes; assignable
task.layer_filter	Which layers the task includes; assignable
task.shape_filter	Which shapes the task includes; assignable

from linkcad.v1.edit import CellFilter, RemoveDuplicatesTask, ShapeFilter

task = RemoveDuplicatesTask(drawing)
task.cell_filter = CellFilter.EnabledCells
task.shape_filter = ShapeFilter.SelectedShapes
task.execute()

Note

A task is bound to the drawing it was created for. Using one after that drawing has been destroyed raises RuntimeError rather than reading freed memory, and dropping a stale task is safe. It is still tidier to keep a task inside the with Drawing(...) block that owns its drawing — the one-liner form below (Task(...).execute()) does that on its own.

Tasks

SnapToGridTask

Snaps shape vertices to the nearest grid point.

from linkcad.v1.db import Transaction
from linkcad.v1.edit import PolygonSnapMode, SnapToGridTask

with Transaction(drawing, "Snap to grid"):
    SnapToGridTask(drawing, 100, PolygonSnapMode.AllAngle).execute()

Parameter	Type	Default	Description
drawing	Drawing	required	Target drawing
grid	int	required	Grid spacing in database units
snap_mode	PolygonSnapMode	AllAngle	Whether to force Manhattan geometry

FlattenTask

Flattens the cell hierarchy below a cell — expands all cell references into that cell. Note that it takes the starting cell, not the drawing.

from linkcad.v1.edit import FlattenTask

FlattenTask(drawing.main_cell).execute()

Parameter	Type	Description
start_cell	Cell	Cell whose references are expanded

RemoveDuplicatesTask

Removes polygons and polylines with identical geometry.

from linkcad.v1.edit import RemoveDuplicatesTask

RemoveDuplicatesTask(drawing).execute()

MergeTask

Merges overlapping polygons on each layer using a boolean union. Curved shapes are tessellated first using the provided Resolution.

from linkcad.v1.edit import EdgePolicy, FillRule, HolesMode, MergeTask
from linkcad.v1.geom import Resolution

res = Resolution()
res.minimum_facets = 32
res.maximum_error = 1

task = MergeTask(
    drawing,
    res,
    FillRule.NonZero,
    HolesMode.Link,
    EdgePolicy.Merge,
    dont_explode=False,
    process_vertically=False,
)
task.execute()

Parameter	Type	Default	Description
drawing	Drawing	required	Target drawing
resolution	Resolution	required	Curve tessellation settings
fill_rule	FillRule	required	Winding rule for determining polygon interior
holes_mode	HolesMode	required	How to represent holes in output polygons
edge_policy	EdgePolicy	required	How to handle inner boundaries
dont_explode	bool	False	If True, do not decompose complex result polygons
process_vertically	bool	False	If True, process cells bottom-up (for hierarchical drawings)

ClosePolylinesTask

Closes open polylines by connecting first and last vertices.

from linkcad.v1.edit import ClosePolylinesTask

ClosePolylinesTask(drawing).execute()

JoinPolylinesTask

Joins polylines whose endpoints touch, within tolerance.

from linkcad.v1.edit import JoinPolylinesTask

task = JoinPolylinesTask(drawing, wire_end_tolerance=10, width_tolerance=1)
task.execute()
print(task.unique_object_count, task.total_object_count)

Parameter	Type	Description
drawing	Drawing	Target drawing
wire_end_tolerance	int	Maximum endpoint gap, in database units
width_tolerance	int	Maximum width difference between joined polylines

PolylineToPolygonTask

Converts closed polylines to filled polygons.

from linkcad.v1.edit import PolylineToPolygonTask
from linkcad.v1.geom import Resolution

PolylineToPolygonTask(drawing, tolerance=0, resolution=Resolution()).execute()

Parameter	Type	Description
drawing	Drawing	Target drawing
tolerance	int	Endpoint gap still treated as closed
resolution	Resolution	Curve tessellation settings

ExplodeToPolygonTask

Converts complex shapes to plain polygons and polylines by tessellation.

from linkcad.v1.edit import ExplodeToPolygonTask, FillRule, HolesMode, ShapesToConvert
from linkcad.v1.geom import Resolution

res = Resolution()
res.minimum_facets = 32

task = ExplodeToPolygonTask(
    drawing, res, FillRule.NonZero, HolesMode.Link, ShapesToConvert.All
)
task.execute()
print(task.unique_object_count, task.total_object_count)

Parameter	Type	Description
drawing	Drawing	Target drawing
resolution	Resolution	Curve tessellation settings
fill_rule	FillRule	Winding rule
holes_mode	HolesMode	How to represent holes
shapes_to_convert	ShapesToConvert	Which shape types to explode

unique_object_count and total_object_count are properties, and are only defined on the two tasks that count anything: ExplodeToPolygonTask and JoinPolylinesTask.

RemoveZeroWidthPolylinesTask

Deletes all polylines with a width of zero.

from linkcad.v1.edit import RemoveZeroWidthPolylinesTask

RemoveZeroWidthPolylinesTask(drawing).execute()

RemoveOverlappingPolylinesTask

Removes polyline segments that overlap other segments on the same layer.

from linkcad.v1.edit import RemoveOverlappingPolylinesTask

RemoveOverlappingPolylinesTask(drawing).execute()

FixSelfIntersectingPolygonsTask

Splits self-intersecting polygons into simple polygons.

from linkcad.v1.edit import FillRule, FixSelfIntersectingPolygonsTask, HolesMode

FixSelfIntersectingPolygonsTask(drawing, FillRule.NonZero, HolesMode.Link).execute()

Parameter	Type	Description
drawing	Drawing	Target drawing
fill_rule	FillRule	Winding rule
holes_mode	HolesMode	How to represent holes

Enums

FillRule

Winding rule used when determining which regions are “inside” a polygon. Re-exported from linkcad.v1.db.

Value	Description
FillRule.NonZero	Non-zero winding rule (standard CAD/EDA convention)
FillRule.EvenOdd	Even-odd (alternating fill) rule

HolesMode

Controls how holes in result polygons are represented. Re-exported from linkcad.v1.plugin.

Value	Description
HolesMode.Link	Link holes to the outer boundary with zero-width bridges
HolesMode.Split	Split polygons so no holes appear in output
HolesMode.Extract	Return holes as separate polygons
HolesMode.Keep	Keep holes as they are

EdgePolicy

Controls how inner boundaries are handled during merge.

Value	Description
EdgePolicy.Keep	Keep original inner boundaries
EdgePolicy.Merge	Merge inner boundaries

PolygonSnapMode

Controls the angles vertices may take after snapping.

Value	Description
PolygonSnapMode.AllAngle	Allow all angles
PolygonSnapMode.ForceManhattan	Force Manhattan (orthogonal) geometry

ShapesToConvert

Selects which shape types ExplodeToPolygonTask converts. Values combine.

Value	Description
ShapesToConvert.None	Nothing
ShapesToConvert.All	Every convertible shape type
ShapesToConvert.Polylines	Polylines
ShapesToConvert.Text	Text
ShapesToConvert.Circles	Circles and ellipses
ShapesToConvert.Arcs	Arcs
ShapesToConvert.Donuts	Donuts
ShapesToConvert.Nurbs	NURBS curves
ShapesToConvert.ZeroWidthClosedPolylines	Closed polylines of zero width

None is a Python keyword, so that member is reachable only as getattr(ShapesToConvert, "None").