[dxf] improve dxf path-to-polygon loading

masque/file/dxf.py

@@ -6,17 +6,21 @@ Notes:
  * ezdxf sets creation time, write time, $VERSIONGUID, and $FINGERPRINTGUID
     to unique values, so byte-for-byte reproducibility is not achievable for now
 """
-from typing import Any, cast, TextIO, IO
-from collections.abc import Mapping, Callable
+from typing import Any, cast, TextIO, IO, Literal
+from collections import defaultdict
+from collections.abc import Mapping, Callable, Sequence
 import io
 import logging
 import pathlib
 import gzip
 
 import numpy
+from numpy.typing import NDArray
 import ezdxf
+from ezdxf import edgeminer
+from ezdxf.math import Vec3
 from ezdxf.enums import TextEntityAlignment
-from ezdxf.entities import LWPolyline, Polyline, Text, Insert, Solid, Trace
+from ezdxf.entities import LWPolyline, Polyline, Text, Insert, Solid, Trace, Line
 
 from .utils import is_gzipped, tmpfile
 from .. import Pattern, Ref, PatternError, Label
@@ -24,6 +28,7 @@ from ..library import ILibraryView, LibraryView, Library
 from ..shapes import Shape, Polygon, Path
 from ..repetition import Grid
 from ..utils import rotation_matrix_2d, layer_t, normalize_mirror
+from ..utils.boolean import _polytree_to_polygons
 
 
 logger = logging.getLogger(__name__)
@@ -173,6 +178,9 @@ def readfile(
 
 def read(
         stream: TextIO,
+        *,
+        polyline_mode: Literal[0, 1, 2, 3, 4] = 2,
+        contour_accuracy: float = 0.0,
         ) -> tuple[Library, dict[str, Any]]:
     """
     Read a dxf file and translate it into a dict of `Pattern` objects. DXF `Block`s are
@@ -183,16 +191,30 @@ def read(
 
     Args:
         stream: Stream to read from.
+        polyline_mode: Treatment of straight LINE/POLYLINE/LWPOLYLINE geometry:
+            0 selects automatically (1 if SOLID/HATCH exists, otherwise 2 if closed
+            polylines exist, otherwise 3); 1 keeps paths; 2 fills closed zero-width
+            polylines; 3 joins zero-width segments into polygons, keeping open
+            contours as paths; 4 additionally closes open contours. Closure may be
+            indicated by the DXF flag or exactly equal endpoints. Positive-width
+            paths are preserved in every mode. Curved and variable-width entities
+            remain unsupported. Automatic selection uses all imported blocks.
+        contour_accuracy: Nonnegative, finite endpoint joining distance in DXF
+            units, used only in modes 3 and 4. Zero requires exact coincidence.
+            Merged polygons are quantized to 1e-6 DXF units and use even-odd filling
+            (nested contours form holes), matching KLayout's polyline merge modes.
 
     Returns:
-        - Top level pattern
+        - Library of patterns
+        - Layer metadata
     """
+    if polyline_mode not in (0, 1, 2, 3, 4):
+        raise ValueError(f'Invalid DXF polyline_mode: {polyline_mode!r}')
+    if not numpy.isfinite(contour_accuracy) or contour_accuracy < 0:
+        raise ValueError('DXF contour_accuracy must be finite and nonnegative')
     lib = ezdxf.read(stream)
     msp = lib.modelspace()
 
-    top_name, top_pat = _read_block(msp)
-    mlib = Library({top_name: top_pat})
-
     blocks_by_name = {
         bb.name: bb
         for bb in lib.blocks
@@ -219,12 +241,27 @@ def read(
             if target in blocks_by_name:
                 pending.append(blocks_by_name[target])
 
-    for bb in lib.blocks:
-        if bb.is_any_layout:
-            continue
-        if bb.name.startswith('_') and bb.name not in referenced:
-            continue
-        name, pat = _read_block(bb)
+    blocks = [msp, *(bb for bb in blocks_by_name.values()
+                      if not bb.name.startswith('_') or bb.name in referenced)]
+    if polyline_mode == 0:
+        polyline_mode = 3
+        for block in blocks:
+            for element in block:
+                if element.dxftype() in ('SOLID', 'HATCH'):
+                    polyline_mode = 1
+                    break
+                if isinstance(element, LWPolyline | Polyline):
+                    verts = (numpy.asarray(element.get_points('xy')) if isinstance(element, LWPolyline)
+                             else numpy.asarray([pp.xyz[:2] for pp in element.points()]))
+                    closed = element.closed if isinstance(element, LWPolyline) else element.is_closed
+                    if closed or (len(verts) > 1 and numpy.array_equal(verts[0], verts[-1])):
+                        polyline_mode = 2
+            if polyline_mode == 1:
+                break
+
+    mlib = Library()
+    for bb in blocks:
+        name, pat = _read_block(bb, polyline_mode=polyline_mode, contour_accuracy=contour_accuracy)
         mlib[name] = pat
 
     library_info = dict(
@@ -234,9 +271,15 @@ def read(
     return mlib, library_info
 
 
-def _read_block(block: ezdxf.layouts.BlockLayout | ezdxf.layouts.Modelspace) -> tuple[str, Pattern]:
+def _read_block(
+        block: ezdxf.layouts.BlockLayout | ezdxf.layouts.Modelspace,
+        *,
+        polyline_mode: int = 2,
+        contour_accuracy: float = 0.0,
+        ) -> tuple[str, Pattern]:
     name = block.name
     pat = Pattern()
+    contours: dict[layer_t, list[numpy.ndarray]] = defaultdict(list)
     for element in block:
         if isinstance(element, LWPolyline | Polyline):
             if isinstance(element, LWPolyline):
@@ -247,6 +290,9 @@ def _read_block(block: ezdxf.layouts.BlockLayout | ezdxf.layouts.Modelspace) ->
                 is_closed = element.is_closed
             attr = element.dxfattribs()
             layer = attr.get('layer', DEFAULT_LAYER)
+            if len(points) < 2:
+                logger.warning('Ignoring DXF polyline with fewer than two vertices')
+                continue
 
             width = 0
             if isinstance(element, LWPolyline):
@@ -260,26 +306,44 @@ def _read_block(block: ezdxf.layouts.BlockLayout | ezdxf.layouts.Modelspace) ->
                 elif points.shape[1] == 3:
                     # width used to be in column 2
                     width = points[0, 2]
+            else:
+                if any(vertex.dxf.get('bulge', 0) != 0 for vertex in element.vertices):
+                    raise PatternError('Polyline has bulge (not yet representable in masque!)')
+                widths = numpy.asarray([
+                    (vertex.dxf.get('start_width', attr.get('default_start_width', 0)),
+                     vertex.dxf.get('end_width', attr.get('default_end_width', 0)))
+                    for vertex in element.vertices
+                    ])
+                if (widths != widths[0, 0]).any():
+                    raise PatternError('Polyline has non-constant width (not yet representable in masque!)')
+                width = widths[0, 0]
 
             if width == 0:
                 width = attr.get('const_width', 0)
 
             verts = points[:, :2]
-            if is_closed and (len(verts) < 2 or not numpy.allclose(verts[0], verts[-1])):
+            endpoint_closed = numpy.array_equal(verts[0], verts[-1])
+            if is_closed and not endpoint_closed:
                 verts = numpy.vstack((verts, verts[0]))
+            is_closed = is_closed or endpoint_closed
 
             shape: Path | Polygon
-            if width == 0 and is_closed:
-                # Use Polygon if it has at least 3 unique vertices
-                shape_verts = verts[:-1] if len(verts) > 1 else verts
-                if len(shape_verts) >= 3:
-                    shape = Polygon(vertices=shape_verts)
-                else:
-                    shape = Path(width=width, vertices=verts)
+            if width == 0 and polyline_mode >= 3:
+                contours[layer].append(verts)
+                continue
+            if width == 0 and is_closed and polyline_mode == 2 and _is_polygon(verts):
+                shape = Polygon(vertices=verts[:-1])
             else:
                 shape = Path(width=width, vertices=verts)
 
             pat.shapes[layer].append(shape)
+        elif isinstance(element, Line):
+            layer = element.dxf.get('layer', DEFAULT_LAYER)
+            verts = numpy.asarray((element.dxf.start.xyz[:2], element.dxf.end.xyz[:2]))
+            if polyline_mode >= 3:
+                contours[layer].append(verts)
+            else:
+                pat.shapes[layer].append(Path(vertices=verts, width=0))
         elif isinstance(element, Solid | Trace):
             attr = element.dxfattribs()
             layer = attr.get('layer', DEFAULT_LAYER)
@@ -316,7 +380,8 @@ def _read_block(block: ezdxf.layouts.BlockLayout | ezdxf.layouts.Modelspace) ->
                 logger.warning('Masque does not support per-axis scaling; using x-scaling only!')
             scale = abs(xscale)
             mirrored, extra_angle = normalize_mirror((yscale < 0, xscale < 0))
-            rotation = numpy.deg2rad(attr.get('rotation', 0)) + extra_angle
+            insert_rotation = numpy.deg2rad(attr.get('rotation', 0))
+            rotation = insert_rotation + extra_angle
 
             offset = numpy.asarray(attr.get('insert', (0, 0, 0)))[:2]
 
@@ -328,64 +393,144 @@ def _read_block(block: ezdxf.layouts.BlockLayout | ezdxf.layouts.Modelspace) ->
                 rotation=rotation,
                 )
 
-            if 'column_count' in attr:
-                col_spacing = attr['column_spacing']
-                row_spacing = attr['row_spacing']
-                col_count = attr['column_count']
-                row_count = attr['row_count']
+            if 'column_count' in attr or 'row_count' in attr:
+                col_spacing = attr.get('column_spacing', 0)
+                row_spacing = attr.get('row_spacing', 0)
+                col_count = attr.get('column_count', 1)
+                row_count = attr.get('row_count', 1)
                 local_x = numpy.array((col_spacing, 0.0))
                 local_y = numpy.array((0.0, row_spacing))
-                inv_rot = rotation_matrix_2d(-rotation)
-
-                candidates = (
-                    (inv_rot @ local_x, inv_rot @ local_y, col_count, row_count),
-                    (inv_rot @ local_y, inv_rot @ local_x, row_count, col_count),
+                # Spacing follows only the original INSERT angle, not its scale
+                # or the extra angle introduced by mirror normalization.
+                rot = rotation_matrix_2d(insert_rotation)
+                args['repetition'] = Grid(
+                    a_vector=rot @ local_x, b_vector=rot @ local_y,
+                    a_count=col_count, b_count=row_count,
                     )
-                repetition = None
-                for a_vector, b_vector, a_count, b_count in candidates:
-                    rotated_a = rotation_matrix_2d(rotation) @ a_vector
-                    rotated_b = rotation_matrix_2d(rotation) @ b_vector
-                    if (numpy.isclose(rotated_a[1], 0, atol=1e-8)
-                            and numpy.isclose(rotated_b[0], 0, atol=1e-8)
-                            and numpy.isclose(rotated_a[0], col_spacing, atol=1e-8)
-                            and numpy.isclose(rotated_b[1], row_spacing, atol=1e-8)
-                            and a_count == col_count
-                            and b_count == row_count):
-                        repetition = Grid(
-                            a_vector=a_vector,
-                            b_vector=b_vector,
-                            a_count=a_count,
-                            b_count=b_count,
-                            )
-                        break
-                    if (numpy.isclose(rotated_a[0], 0, atol=1e-8)
-                            and numpy.isclose(rotated_b[1], 0, atol=1e-8)
-                            and numpy.isclose(rotated_b[0], col_spacing, atol=1e-8)
-                            and numpy.isclose(rotated_a[1], row_spacing, atol=1e-8)
-                            and b_count == col_count
-                            and a_count == row_count):
-                        repetition = Grid(
-                            a_vector=a_vector,
-                            b_vector=b_vector,
-                            a_count=a_count,
-                            b_count=b_count,
-                            )
-                        break
-
-                if repetition is None:
-                    repetition = Grid(
-                        a_vector=inv_rot @ local_x,
-                        b_vector=inv_rot @ local_y,
-                        a_count=col_count,
-                        b_count=row_count,
-                        )
-                args['repetition'] = repetition
             pat.ref(**args)
         else:
             logger.warning(f'Ignoring DXF element {element.dxftype()} (not implemented).')
+    for layer, vertex_lists in contours.items():
+        pat.shapes[layer].extend(_merge_polylines(vertex_lists, contour_accuracy, auto_close=polyline_mode == 4))
     return name, pat
 
 
+def _is_polygon(vertices: NDArray) -> bool:
+    """At least three distinct, noncollinear points (including self-crossing contours)."""
+    points = numpy.unique(vertices, axis=0)
+    if len(points) < 3:
+        return False
+    vectors = points[1:] - points[0]
+    return bool(numpy.any(vectors[:, 0] * vectors[0, 1] != vectors[:, 1] * vectors[0, 0]))
+
+
+def _contours(edges: Sequence[edgeminer.Edge], accuracy: float) -> list[tuple[NDArray, bool]]:
+    """Join each edge once, using indexed endpoint searches rather than loop enumeration."""
+    deposit = edgeminer.Deposit(edges, gap_tol=accuracy)
+    unused = {edge.id for edge in edges}
+    result = []
+
+    def grow(points: list[Vec3]) -> bool:
+        positions = {point: index for index, point in enumerate(points[:-1])}
+        while True:
+            # A walk that started on a dangling segment can encounter a cycle
+            # before returning to its initial point. Extract that rim and keep
+            # the remaining open tail; every segment is still consumed once.
+            contacts = {
+                point for edge in deposit.edges_linked_to(points[-1])
+                for point in (edge.start, edge.end)
+                if point in positions and positions[point] < len(points) - 2
+                and point.distance(points[-1]) <= accuracy
+                }
+            if contacts:
+                point = min(contacts, key=lambda point: (point.distance(points[-1]), point.xyz))
+                index = positions[point]
+                loop = points[index:-1] + [point]
+                result.append((numpy.asarray([pp.xyz[:2] for pp in loop]), True))
+                if index == 0:
+                    return True
+                for removed in points[index + 1:-1]:
+                    positions.pop(removed, None)
+                del points[index + 1:]
+            positions[points[-1]] = len(points) - 1
+            incoming = points[-1] - points[-2]
+            candidates = []
+            for edge in deposit.edges_linked_to(points[-1]):
+                if edge.id not in unused:
+                    continue
+                for oriented in (edge, edge.reversed()):
+                    distance = points[-1].distance(oriented.start)
+                    if distance <= accuracy:
+                        direction = oriented.end - oriented.start
+                        # Like KLayout, use endpoint distance then a signed
+                        # cross product. Canonical seeds follow clockwise rims.
+                        turn = -direction.cross(incoming).z / oriented.length
+                        candidates.append((distance, turn, oriented.end.xyz, oriented.id, oriented))
+            if not candidates:
+                return False
+            edge = min(candidates, key=lambda item: item[:4])[-1]
+            unused.remove(edge.id)
+            # Snap the next start to the preceding endpoint when joining a gap.
+            points.append(edge.end)
+
+    # Canonical ordering makes results independent of input order/direction.
+    ordered = sorted(edges, key=lambda edge: sorted((edge.start.xyz, edge.end.xyz)))
+    for seed in ordered:
+        if seed.id not in unused:
+            continue
+        unused.remove(seed.id)
+        edge = seed.reversed() if seed.start.xyz > seed.end.xyz else seed
+        points = [edge.start, edge.end]
+        closed = grow(points)
+        if not closed:
+            points.reverse()
+            closed = grow(points)
+        if not closed:
+            result.append((numpy.asarray([point.xyz[:2] for point in points]), False))
+    return result
+
+
+def _merge_polylines(
+        vertex_lists: Sequence[NDArray],
+        accuracy: float,
+        *,
+        auto_close: bool,
+        ) -> list[Path | Polygon]:
+    """Assemble one cell/layer's zero-width segments, with KLayout's even-odd fill."""
+    import pyclipper        # noqa: PLC0415
+
+    edges = []
+    result: list[Path | Polygon] = []
+    for vertices in vertex_lists:
+        start_count = len(edges)
+        for start, end in zip(vertices[:-1], vertices[1:], strict=True):
+            if not numpy.array_equal(start, end):
+                edges.append(edgeminer.make_edge(start, end))
+        if start_count == len(edges):
+            result.append(Path(vertices=vertices, width=0))
+
+    scale = 1e6
+    clipper = pyclipper.Pyclipper()
+    has_polygons = False
+    for vertices, closed in _contours(edges, accuracy):
+        if (closed or auto_close) and _is_polygon(vertices):
+            # A contour can collapse at the clipping precision. Preserve its
+            # centerline in that case rather than silently dropping geometry.
+            try:
+                added = clipper.AddPath(pyclipper.scale_to_clipper(vertices, scale), pyclipper.PT_SUBJECT, True)
+            except pyclipper.ClipperException:
+                added = False
+            if added:
+                has_polygons = True
+                continue
+        result.append(Path(vertices=vertices, width=0))
+
+    if has_polygons:
+        tree = clipper.Execute2(pyclipper.CT_UNION, pyclipper.PFT_EVENODD, pyclipper.PFT_EVENODD)
+        result.extend(_polytree_to_polygons(tree, scale))
+    return result
+
+
 def _mrefs_to_drefs(
         block: ezdxf.layouts.BlockLayout | ezdxf.layouts.Modelspace,
         refs: dict[str | None, list[Ref]],
@@ -407,12 +552,10 @@ def _mrefs_to_drefs(
             # In masque, the grid basis vectors are NOT rotated by the reference's rotation.
             # In DXF, the grid basis vectors are [column_spacing, 0] and [0, row_spacing],
             # which ARE then rotated by the block reference's rotation.
-            # Therefore, we can only use a DXF array if ref.rotation is 0 (or a multiple of 90)
-            # AND the grid is already manhattan.
-
-            # Rotate basis vectors by the reference rotation to see where they end up in the DXF frame
-            rotated_a = rotation_matrix_2d(ref.rotation) @ a
-            rotated_b = rotation_matrix_2d(ref.rotation) @ b
+            # Compensate for that rotation to express the world-space basis in
+            # the local DXF frame. Only locally Manhattan grids fit an INSERT.
+            rotated_a = rotation_matrix_2d(-ref.rotation) @ a
+            rotated_b = rotation_matrix_2d(-ref.rotation) @ b
 
             if numpy.isclose(rotated_a[1], 0, atol=1e-8) and numpy.isclose(rotated_b[0], 0, atol=1e-8):
                 attribs['column_count'] = rep.a_count

masque/test/test_dxf_modes.py

@@ -0,0 +1,205 @@
+"""DXF geometry checks independent of masque's writer/reader round trips."""
+import io
+
+import ezdxf
+import numpy
+import pytest
+from numpy.testing import assert_allclose
+
+from ..file import dxf
+from ..library import Library
+from ..pattern import Pattern
+from ..repetition import Grid
+from ..shapes import Path, Polygon
+
+
+def _read(doc: ezdxf.document.Drawing, mode: int = 2, accuracy: float = 0.0) -> Library:
+    stream = io.StringIO()
+    doc.write(stream)
+    stream.seek(0)
+    return dxf.read(stream, polyline_mode=mode, contour_accuracy=accuracy)[0]
+
+
+def _area(shapes: list) -> float:
+    total = 0.0
+    for shape in shapes:
+        if isinstance(shape, Polygon):
+            xx, yy = shape.vertices.T
+            total += abs(numpy.dot(xx, numpy.roll(yy, 1)) - numpy.dot(yy, numpy.roll(xx, 1))) / 2
+    return total
+
+
+def _origins(rows: numpy.ndarray) -> numpy.ndarray:
+    rounded = numpy.round(rows, 8)
+    return rounded[numpy.lexsort((rounded[:, 1], rounded[:, 0]))]
+
+
+@pytest.mark.parametrize('legacy', [False, True])
+@pytest.mark.parametrize('flagged', [False, True])
+@pytest.mark.parametrize('mode', [0, 1, 2, 3, 4])
+def test_closed_polylines(legacy: bool, flagged: bool, mode: int) -> None:
+    doc = ezdxf.new()
+    points = [(0, 0), (10, 0), (10, 10), (0, 10)]
+    if not flagged:
+        points.append(points[0])
+    msp = doc.modelspace()
+    if legacy:
+        msp.add_polyline2d(points).close(flagged)
+    else:
+        msp.add_lwpolyline(points, close=flagged)
+    shapes = _read(doc, mode)['Model'].shapes['0']
+    assert len(shapes) == 1
+    assert isinstance(shapes[0], Path if mode == 1 else Polygon)
+    assert _area(shapes) == (0 if mode == 1 else 100)
+    if mode == 1:
+        assert_allclose(shapes[0].vertices[0], shapes[0].vertices[-1])
+
+
+@pytest.mark.parametrize('mode', [0, 1, 2, 3, 4])
+@pytest.mark.parametrize('closed', [False, True])
+def test_join_shuffled_lines(mode: int, closed: bool) -> None:
+    doc = ezdxf.new()
+    segments = [((10, 10), (10, 0)), ((0, 0), (10, 0)), ((0, 10), (10, 10))]
+    if closed:
+        segments.append(((0, 0), (0, 10)))
+    for start, end in segments:
+        doc.modelspace().add_line(start, end)
+    shapes = _read(doc, mode)['Model'].shapes['0']
+    filled = mode == 4 or (closed and mode in (0, 3))
+    assert _area(shapes) == (100 if filled else 0)
+    assert len(shapes) == (len(segments) if mode in (1, 2) else 1)
+
+
+@pytest.mark.parametrize('entity', ['SOLID', 'HATCH'])
+def test_auto_detects_solids_in_child_blocks(entity: str) -> None:
+    doc = ezdxf.new()
+    doc.modelspace().add_lwpolyline([(0, 0), (4, 0), (4, 4)], close=True)
+    block = doc.blocks.new('child')
+    if entity == 'SOLID':
+        block.add_solid([(0, 0), (1, 0), (1, 1)])
+    else:
+        block.add_hatch()
+    doc.modelspace().add_blockref('child', (0, 0))
+    assert isinstance(_read(doc, 0)['Model'].shapes['0'][0], Path)
+
+
+@pytest.mark.parametrize(('accuracy', 'expected'), [(0, 0), (0.005, 0), (0.02, 100)])
+def test_contour_tolerance(accuracy: float, expected: float) -> None:
+    doc = ezdxf.new()
+    doc.modelspace().add_lwpolyline([(0, 0), (10, 0), (10, 10), (0, 10), (0, 0.01)])
+    shapes = _read(doc, 3, accuracy)['Model'].shapes['0']
+    assert _area(shapes) == expected
+
+
+@pytest.mark.parametrize('mode', [3, 4])
+def test_nested_contours_resolve_holes_and_islands(mode: int) -> None:
+    doc = ezdxf.new()
+    for lo, hi in [(0, 10), (2, 8), (4, 6)]:
+        doc.modelspace().add_lwpolyline([(lo, lo), (hi, lo), (hi, hi), (lo, hi)], close=True)
+    shapes = _read(doc, mode)['Model'].shapes['0']
+    assert len(shapes) == 2
+    assert _area(shapes) == 68
+
+
+@pytest.mark.parametrize('mode', [3, 4])
+def test_layers_and_blocks_are_not_joined(mode: int) -> None:
+    doc = ezdxf.new()
+    doc.modelspace().add_line((0, 0), (10, 0), dxfattribs={'layer': 'a'})
+    doc.modelspace().add_line((10, 0), (0, 10), dxfattribs={'layer': 'b'})
+    doc.blocks.new('child').add_line((0, 10), (0, 0), dxfattribs={'layer': 'a'})
+    lib = _read(doc, mode)
+    assert all(isinstance(shape, Path) for pat in lib.values() for shapes in pat.shapes.values() for shape in shapes)
+
+
+@pytest.mark.parametrize('mode', [0, 1, 2, 3, 4])
+@pytest.mark.parametrize('legacy', [False, True])
+def test_width_and_degenerate_paths_are_preserved(mode: int, legacy: bool) -> None:
+    doc = ezdxf.new()
+    if legacy:
+        doc.modelspace().add_polyline2d([(0, 0), (2, 0), (2, 2)], dxfattribs={
+            'default_start_width': 2, 'default_end_width': 2,
+            }).close(True)
+    else:
+        doc.modelspace().add_lwpolyline([(0, 0), (2, 0), (2, 2)], close=True, dxfattribs={'const_width': 2})
+    doc.modelspace().add_lwpolyline([(10, 0), (10, 0)])
+    doc.modelspace().add_lwpolyline([(20, 0), (21, 0), (22, 0)])
+    shapes = _read(doc, mode)['Model'].shapes['0']
+    assert len(shapes) == 3
+    assert all(isinstance(shape, Path) for shape in shapes)
+    assert sorted(shape.width for shape in shapes) == [0, 0, 2]
+
+
+@pytest.mark.parametrize('mode', [3, 4])
+@pytest.mark.parametrize('spur', [((10, 0), (12, 0)), ((-2, 0), (0, 0)), ((0, -2), (0, 0))])
+def test_branch_and_shuffling_preserve_square(mode: int, spur: tuple) -> None:
+    segments = [((0, 0), (10, 0)), ((10, 0), (10, 10)), ((10, 10), (0, 10)),
+                ((0, 10), (0, 0)), spur]
+    for order in (segments, [(b, a) for a, b in segments[::-1]]):
+        doc = ezdxf.new()
+        for start, end in order:
+            doc.modelspace().add_line(start, end)
+        shapes = _read(doc, mode)['Model'].shapes['0']
+        assert _area(shapes) == 100
+        assert len(shapes) == 2
+
+
+@pytest.mark.parametrize('mode', [-1, 5, 'closed'])
+def test_invalid_polyline_mode(mode: int) -> None:
+    with pytest.raises(ValueError, match='polyline_mode'):
+        _read(ezdxf.new(), mode)
+
+
+@pytest.mark.parametrize('mode', [3, 4])
+def test_merge_uses_even_odd_filling_for_overlapping_contours(mode: int) -> None:
+    doc = ezdxf.new()
+    for xx in (0, 5):
+        doc.modelspace().add_lwpolyline([(xx, 0), (xx + 10, 0), (xx + 10, 10), (xx, 10)], close=True)
+    assert _area(_read(doc, mode)['Model'].shapes['0']) == 100
+
+
+@pytest.mark.parametrize('mode', [3, 4])
+def test_contours_below_clipping_precision_remain_paths(mode: int) -> None:
+    doc = ezdxf.new()
+    doc.modelspace().add_lwpolyline([(0, 0), (1e-7, 0), (0, 1e-7)], close=True)
+    shapes = _read(doc, mode)['Model'].shapes['0']
+    assert len(shapes) == 1
+    assert isinstance(shapes[0], Path)
+    assert_allclose(shapes[0].get_bounds_single(), [[0, 0], [1e-7, 1e-7]], atol=1e-15)
+
+
+@pytest.mark.parametrize('accuracy', [-1, numpy.nan, numpy.inf])
+def test_invalid_contour_accuracy(accuracy: float) -> None:
+    with pytest.raises(ValueError, match='contour_accuracy'):
+        _read(ezdxf.new(), 3, accuracy)
+
+
+@pytest.mark.parametrize('angle', [0, numpy.pi / 2, numpy.pi, numpy.pi / 4])
+@pytest.mark.parametrize('local_grid', [False, True])
+@pytest.mark.parametrize('mirrored', [False, True])
+def test_exported_insert_origins(angle: float, local_grid: bool, mirrored: bool) -> None:
+    lib = Library({'leaf': Pattern(), 'top': Pattern()})
+    lib['leaf'].polygon('1', vertices=[(0, 0), (4, 0), (0, 2)])
+    rep = Grid(a_vector=(10, 0), a_count=3, b_vector=(0, 20), b_count=2)
+    if local_grid:
+        rep.rotate(angle)
+    lib['top'].ref('leaf', offset=(5, 7), rotation=angle, scale=2, mirrored=mirrored, repetition=rep)
+    stream = io.StringIO()
+    dxf.write(lib, 'top', stream)
+    stream.seek(0)
+    inserts = ezdxf.read(stream).modelspace().query('INSERT')
+    origins = [instance.dxf.insert.xyz[:2] for ins in inserts for instance in ins.multi_insert()]
+    assert_allclose(_origins(numpy.asarray(origins)), _origins(rep.displacements + (5, 7)), atol=1e-7)
+
+
+@pytest.mark.parametrize('scales', [(1, 1), (-1, 1), (1, -1), (-1, -1), (2, 2)])
+@pytest.mark.parametrize('angle', [0, 30, 90])
+def test_imported_insert_origins(scales: tuple[float, float], angle: float) -> None:
+    doc = ezdxf.new()
+    doc.blocks.new('leaf')
+    insert = doc.modelspace().add_blockref('leaf', (5, 7), dxfattribs={
+        'rotation': angle, 'xscale': scales[0], 'yscale': scales[1],
+        'column_count': 3, 'row_count': 2, 'column_spacing': 20, 'row_spacing': -10,
+        })
+    expected = numpy.asarray([ins.dxf.insert.xyz[:2] for ins in insert.multi_insert()])
+    ref = _read(doc)['Model'].refs['leaf'][0]
+    assert_allclose(_origins(ref.as_transforms()[:, :2]), _origins(expected), atol=1e-7)

pyproject.toml

@@ -69,7 +69,7 @@ path = "masque/__init__.py"
 [project.optional-dependencies]
 arrow = ["pyarrow", "cffi"]
 oasis = ["fatamorgana~=0.11"]
-dxf = ["ezdxf~=1.4"]
+dxf = ["ezdxf~=1.4", "pyclipper"]
 svg = ["svgwrite"]
 visualize = ["matplotlib"]
 text = ["matplotlib", "freetype-py"]