dxf splines and ellipse import support

cadquery/occ_impl/importers.py

@@ -1,15 +1,26 @@
+from collections import OrderedDict
+from math import pi
+
 from .. import cq
 from .geom import Vector
-from .shapes import Shape, Edge, Face, sortWiresByBuildOrder
+from .shapes import Shape, Edge, Face, sortWiresByBuildOrder, DEG2RAD
 
 import ezdxf
 
 from OCP.STEPControl import STEPControl_Reader
 from OCP.ShapeAnalysis import ShapeAnalysis_FreeBounds
 from OCP.TopTools import TopTools_HSequenceOfShape
+from OCP.gp import gp_Pnt
+from OCP.Geom import Geom_BSplineCurve
+from OCP.TColgp import TColgp_Array1OfPnt
+from OCP.TColStd import TColStd_Array1OfReal, TColStd_Array1OfInteger
+from OCP.BRepBuilderAPI import BRepBuilderAPI_MakeEdge
+
 
 import OCP.IFSelect
 
+RAD2DEG = 360.0 / (2 * pi)
+
 
 class ImportTypes:
  STEP = "STEP"
@@ -104,12 +115,79 @@ def _dxf_polyline(el):
  return (e[0] for e in rv if e)
 
 
+def _dxf_spline(el):
+
+ try:
+ degree = el.dxf.degree
+ periodic = el.closed
+ rational = False
+
+ knots_unique = OrderedDict()
+ for k in el.knots:
+ if k in knots_unique:
+ knots_unique[k] += 1
+ else:
+ knots_unique[k] = 1
+
+ # assmble knots
+ knots = TColStd_Array1OfReal(1, len(knots_unique))
+ multiplicities = TColStd_Array1OfInteger(1, len(knots_unique))
+ for i, (k, m) in enumerate(knots_unique.items()):
+ knots.SetValue(i + 1, k)
+ multiplicities.SetValue(i + 1, m)
+
+ # assemble wieghts if present:
+ if el.weights:
+ rational = True
+
+ weights = OCP.TColStd.TColStd_Array1OfReal(1, len(el.weights))
+ for i, w in enumerate(el.weights):
+ weights.SetValue(i + 1, w)
+
+ # assmeble conotrol points
+ pts = TColgp_Array1OfPnt(1, len(el.control_points))
+ for i, p in enumerate(el.control_points):
+ pts.SetValue(i + 1, gp_Pnt(*p))
+
+ if rational:
+ spline = Geom_BSplineCurve(
+ pts, weights, knots, multiplicities, degree, periodic
+ )
+ else:
+ spline = Geom_BSplineCurve(pts, knots, multiplicities, degree, periodic)
+
+ return (Edge(BRepBuilderAPI_MakeEdge(spline).Edge()),)
+
+ except Exception:
+ return ()
+
+
+def _dxf_ellipse(el):
+
+ try:
+
+ return (
+ Edge.makeEllipse(
+ el.dxf.major_axis.magnitude,
+ el.minor_axis.magnitude,
+ pnt=Vector(el.dxf.center.xyz),
+ xdir=Vector(el.dxf.major_axis.xyz),
+ angle1=el.dxf.start_param * RAD2DEG,
+ angle2=el.dxf.end_param * RAD2DEG,
+ ),
+ )
+ except Exception:
+ return ()
+
+
 DXF_CONVERTERS = {
  "LINE": _dxf_line,
  "CIRCLE": _dxf_circle,
  "ARC": _dxf_arc,
  "POLYLINE": _dxf_polyline,
  "LWPOLYLINE": _dxf_polyline,
+ "SPLINE": _dxf_spline,
+ "ELLIPSE": _dxf_ellipse,
 }
 
 

tests/test_importers.py

@@ -109,6 +109,27 @@ def testImportDXF(self):
  obj = importers.importDXF(filename)
  self.assertTrue(obj.val().isValid())
 
+ # test spline import
+
+ filename = os.path.join(testdataDir, "spline.dxf")
+ obj = importers.importDXF(filename, tol=1)
+ self.assertTrue(obj.val().isValid())
+ self.assertEqual(obj.faces().size(), 1)
+ self.assertEqual(obj.wires().size(), 2)
+
+ # test rational spline import
+ filename = os.path.join(testdataDir, "rational_spline.dxf")
+ obj = importers.importDXF(filename)
+ self.assertTrue(obj.val().isValid())
+ self.assertEqual(obj.faces().size(), 1)
+ self.assertEqual(obj.edges().size(), 1)
+
+ # importing of a complex shape exported from Inkscape
+ filename = os.path.join(testdataDir, "genshi.dxf")
+ obj = importers.importDXF(filename)
+ self.assertTrue(obj.val().isValid())
+ self.assertEqual(obj.faces().size(), 1)
+
 
 if __name__ == "__main__":
  import unittest