include/opencascade/BRepOffset.hxx

0001 // Created on: 1995-10-12
0002 // Created by: Bruno DUMORTIER
0003 // Copyright (c) 1995-1999 Matra Datavision
0004 // Copyright (c) 1999-2014 OPEN CASCADE SAS
0005 //
0006 // This file is part of Open CASCADE Technology software library.
0007 //
0008 // This library is free software; you can redistribute it and/or modify it under
0009 // the terms of the GNU Lesser General Public License version 2.1 as published
0010 // by the Free Software Foundation, with special exception defined in the file
0011 // OCCT_LGPL_EXCEPTION.txt. Consult the file LICENSE_LGPL_21.txt included in OCCT
0012 // distribution for complete text of the license and disclaimer of any warranty.
0013 //
0014 // Alternatively, this file may be used under the terms of Open CASCADE
0015 // commercial license or contractual agreement.
0016
0017 #ifndef _BRepOffset_HeaderFile
0018 #define _BRepOffset_HeaderFile
0019
0020 #include <Standard.hxx>
0021 #include <Standard_DefineAlloc.hxx>
0022 #include <Standard_Handle.hxx>
0023
0024 #include <BRepOffset_Status.hxx>
0025
0026 class Geom_Surface;
0027 class TopoDS_Face;
0028
0029 //! Auxiliary tools for offset algorithms
0030
0031 class BRepOffset
0032 {
0033 public:
0034
0035   //! returns   the  Offset  surface  computed from  the
0036   //! surface <Surface> at an OffsetDistance <Offset>.
0037   //!
0038   //! If possible, this method returns  the real type of
0039   //! the surface ( e.g. An Offset of a plane is a plane).
0040   //!
0041   //! If  no particular  case  is detected, the returned
0042   //! surface will have the Type Geom_OffsetSurface.
0043   //! Parameter allowC0 is then passed as last argument to
0044   //! constructor of Geom_OffsetSurface.
0045   Standard_EXPORT static Handle(Geom_Surface) Surface (const Handle(Geom_Surface)& Surface,
0046                                                        const Standard_Real Offset,
0047                                                        BRepOffset_Status& theStatus,
0048                                                        Standard_Boolean allowC0 = Standard_False);
0049
0050   //! Preprocess surface to be offset (bspline, bezier, or revolution based on
0051   //! bspline or bezier curve), by collapsing each singular side to single point.
0052   //!
0053   //! This is to avoid possible flipping of normal at the singularity
0054   //! of the surface due to non-zero distance between the poles that
0055   //! logically should be in one point (singularity).
0056   //!
0057   //! The (parametric) side of the surface is considered to be singularity if face
0058   //! has degenerated edge whose vertex encompasses (by its tolerance) all points on that side,
0059   //! or if all poles defining that side fit into sphere with radius thePrecision.
0060   //!
0061   //! Returns either original surface or its modified copy (if some poles have been moved).
0062   Standard_EXPORT static Handle(Geom_Surface) CollapseSingularities (const Handle(Geom_Surface)& theSurface,
0063                                                                      const TopoDS_Face& theFace,
0064                                                                      Standard_Real thePrecision);
0065
0066 };
0067
0068 #endif // _BRepOffset_HeaderFile