hdZddlmZddlmZmZmZddlmZddl m Z m Z m Z m Z mZer ddlmZddlmZGdd Zy ) a DXF R12 Splines =============== DXF R12 supports 2d B-splines, but Autodesk do not document the usage in the DXF Reference. The base entity for splines in DXF R12 is the POLYLINE entity. Transformed Into 3D Space ------------------------- The spline itself is always in a plane, but as any 2D entity, the spline can be transformed into the 3D object by elevation, extrusion and thickness/width. Open Quadratic Spline with Fit Vertices ------------------------------------- Example: 2D_SPLINE_QUADRATIC.dxf expected knot vector: open uniform degree: 2 order: 3 POLYLINE: flags (70): 4 = SPLINE_FIT_VERTICES_ADDED smooth type (75): 5 = QUADRATIC_BSPLINE Sequence of VERTEX flags (70): SPLINE_VERTEX_CREATED = 8 # Spline vertex created by spline-fitting This vertices are the curve vertices of the spline (fitted). Frame control vertices appear after the curve vertices. Sequence of VERTEX flags (70): SPLINE_FRAME_CONTROL_POINT = 16 No control point at the starting point, but a control point at the end point, last control point == last fit vertex Closed Quadratic Spline with Fit Vertices ----------------------------------------- Example: 2D_SPLINE_QUADRATIC_CLOSED.dxf expected knot vector: closed uniform degree: 2 order: 3 POLYLINE: flags (70): 5 = CLOSED | SPLINE_FIT_VERTICES_ADDED smooth type (75): 5 = QUADRATIC_BSPLINE Sequence of VERTEX flags (70): SPLINE_VERTEX_CREATED = 8 # Spline vertex created by spline-fitting Frame control vertices appear after the curve vertices. Sequence of VERTEX flags (70): SPLINE_FRAME_CONTROL_POINT = 16 Open Cubic Spline with Fit Vertices ----------------------------------- Example: 2D_SPLINE_CUBIC.dxf expected knot vector: open uniform degree: 3 order: 4 POLYLINE: flags (70): 4 = SPLINE_FIT_VERTICES_ADDED smooth type (75): 6 = CUBIC_BSPLINE Sequence of VERTEX flags (70): SPLINE_VERTEX_CREATED = 8 # Spline vertex created by spline-fitting This vertices are the curve vertices of the spline (fitted). Frame control vertices appear after the curve vertices. Sequence of VERTEX flags (70): SPLINE_FRAME_CONTROL_POINT = 16 No control point at the starting point, but a control point at the end point, last control point == last fit vertex Closed Curve With Extra Vertices Created ---------------------------------------- Example: 2D_FIT_CURVE_CLOSED.dxf POLYLINE: flags (70): 3 = CLOSED | CURVE_FIT_VERTICES_ADDED Vertices with bulge values: flags (70): 1 = EXTRA_VERTEX_CREATED Vertex 70=0, Vertex 70=1, Vertex 70=0, Vertex 70=1 ) annotations) TYPE_CHECKINGIterableOptional)const)BSplineclosed_uniform_bsplineVec3UCSUVec) BaseLayout)Polylinec\eZdZdZ d ddZ d d dZ d d dZy) R12SplineaDXF R12 supports 2D B-splines, but Autodesk do not document the usage in the DXF Reference. The base entity for splines in DXF R12 is the POLYLINE entity. The spline itself is always in a plane, but as any 2D entity, the spline can be transformed into the 3D object by elevation and extrusion (:ref:`OCS`, :ref:`UCS`). This way it was possible to store the spline parameters in the DXF R12 file, to allow CAD applications to modify the spline parameters and rerender the B-spline afterward again as polyline approximation. Therefore, the result is not better than an approximation by the :class:`Spline` class, it is also just a POLYLINE entity, but maybe someone need exact this tool in the future. cTtj||_||_||_y)z Args: control_points: B-spline control frame vertices degree: degree of B-spline, only 2 and 3 is supported closed: ``True`` for closed curve N)r listcontrol_pointsdegreeclosed)selfrrrs 6lib/python3.12/site-packages/ezdxf/render/r12spline.py__init__zR12Spline.__init__s##ii7  Nc|jr%t|j|jdz}n$t |j|jdz}|j |} fd|D}t |S)alApproximate the B-spline by a polyline with `segments` line segments. If `ucs` is not ``None``, ucs defines an :class:`~ezdxf.math.UCS`, to transform the curve into :ref:`OCS`. The control points are placed xy-plane of the UCS, don't use z-axis coordinates, if so make sure all control points are in a plane parallel to the OCS base plane (UCS xy-plane), else the result is unpredictable and depends on the CAD application used to open the DXF file - it may crash. Args: segments: count of line segments for approximation, vertex count is `segments` + 1 ucs: :class:`~ezdxf.math.UCS` definition, control points in ucs coordinates Returns: list of vertices in :class:`~ezdxf.math.OCS` as :class:`~ezdxf.math.Vec3` objects )orderc3@K|]}j|yw)N)to_ocs).0vertexucss r z(R12Spline.approximate..sBv 6*s)rr rrr approximater)rsegmentsr!splineverticess ` rr#zR12Spline.approximatesn, ;;+##4;;?FT00 aHF%%h/ ?BBHH~rc|jg|}|j}|jr||jz}||j_|j dk(r |j}n'|j dk(r |j}n td||j_ ||j|j_ |j|j|||jjt j"d|j$}|;t'|j)|}dd|dj*f|j_|j||jjt j.d|S)aTRenders the B-spline into `layout` as 2D :class:`~ezdxf.entities.Polyline` entity. Use an :class:`~ezdxf.math.UCS` to place the 2D spline in the 3D space, see :meth:`approximate` for more information. Args: layout: :class:`~ezdxf.layouts.BaseLayout` object segments: count of line segments for approximation, vertex count is `segments` + 1 ucs: :class:`~ezdxf.math.UCS` definition, control points in ucs coordinates. dxfattribs: DXF attributes for :class:`~ezdxf.entities.Polyline` )points dxfattribszinvalid degree of spline)layerflags)r)r)add_polyline2dSPLINE_FIT_VERTICES_ADDEDrCLOSEDdxfr-rQUADRATIC_BSPLINE CUBIC_BSPLINE ValueError smooth_typeuz extrusionappend_verticesr#r,rVTX_SPLINE_VERTEX_CREATEDrr points_to_ocsz elevationVTX_SPLINE_FRAME_CONTROL_POINT) rlayoutr$r!r)polyliner-r5rs rrenderzR12Spline.renders_(((z(J22 ;; X__ $E"  ;;! "44K [[A "00K78 8#.   ?%(VVHLL "     Xs +!++88 ! ,, ?!#"3"3N"CDN&'N1,=,?,?%@HLL "  !++== ! r)r*T)rzIterable[UVec]rintrbool)(N)r$rAr! Optional[UCS]returnz list[UVec])rCNN)r>r r$rAr!rDrEr)__name__ __module__ __qualname____doc__rr#r@rrrros $ & $8<'4 H! ;;; ;  ;rrN)rI __future__rtypingrrr ezdxf.lldxfr ezdxf.mathrr r r r ezdxf.layoutsr ezdxf.entitiesrrrJrrrQs5aD#44GG('}}r