include/opencascade/BRepOffset_MakeSimpleOffset.hxx

0001 // Created on: 2016-10-13
0002 // Created by: Alexander MALYSHEV
0003 // Copyright (c) 1999-2016 OPEN CASCADE SAS
0004 //
0005 // This file is part of Open CASCADE Technology software library.
0006 //
0007 // This library is free software; you can redistribute it and/or modify it under
0008 // the terms of the GNU Lesser General Public License version 2.1 as published
0009 // by the Free Software Foundation, with special exception defined in the file
0010 // OCCT_LGPL_EXCEPTION.txt. Consult the file LICENSE_LGPL_21.txt included in OCCT
0011 // distribution for complete text of the license and disclaimer of any warranty.
0012 //
0013 // Alternatively, this file may be used under the terms of Open CASCADE
0014 // commercial license or contractual agreement.
0015
0016 #ifndef _BRepOffset_MakeSimpleOffset_HeaderFile
0017 #define _BRepOffset_MakeSimpleOffset_HeaderFile
0018
0019 #include <BRepTools_Modifier.hxx>
0020 #include <ShapeBuild_ReShape.hxx>
0021 #include <NCollection_DataMap.hxx>
0022 #include <Standard_Macro.hxx>
0023 #include <Standard_Real.hxx>
0024 #include <TCollection_AsciiString.hxx>
0025 #include <TopoDS_Edge.hxx>
0026 #include <TopoDS_Face.hxx>
0027 #include <TopoDS_Vertex.hxx>
0028 #include <TopoDS_Shape.hxx>
0029
0030 enum BRepOffsetSimple_Status
0031 {
0032   BRepOffsetSimple_OK,
0033   BRepOffsetSimple_NullInputShape,
0034   BRepOffsetSimple_ErrorOffsetComputation,
0035   BRepOffsetSimple_ErrorWallFaceComputation,
0036   BRepOffsetSimple_ErrorInvalidNbShells,
0037   BRepOffsetSimple_ErrorNonClosedShell
0038 };
0039
0040 //! This class represents simple offset algorithm itself. It builds simple offset without
0041 //! intersection. Solid can be created using SetBuildSolidFlag method (set flag to true). By default
0042 //! shell will be constructed.
0043 //!
0044 //! Algorithm:
0045 //! 1. Build source-image maps for vertices, edges and faces.BRepTools_Modification class will be
0046 //! used
0047 //!    to store this information. An image of a shared edge can be constructed from the
0048 //!    corresponding edge of the first iterated face.
0049 //! 2. Run BRepTools_Modifier to obtain offset shape.
0050 //  3. Ensure topological integrity of the output shape.
0051 //!
0052 //! Limitations:
0053 //! According to the algorithm nature result depends on the smoothness of input data. Smooth
0054 //! (G1-continuity) input shape will lead to the good result.
0055 //!
0056 //! The possible drawback of the simple algorithm is that it leads, in general case, to tolerance
0057 //! increasing. The tolerances have to grow in order to cover the gaps between the neighbor faces in
0058 //! the output. It should be noted that the actual tolerance growth depends on the offset distance
0059 //! and the quality of joints between the input faces. Anyway the good input shell (smooth
0060 //! connections between adjacent faces) will lead to good result.
0061 class BRepOffset_MakeSimpleOffset
0062 {
0063 public:
0064   //! Constructor. Does nothing.
0065   Standard_EXPORT BRepOffset_MakeSimpleOffset();
0066
0067   //! Constructor.
0068   Standard_EXPORT BRepOffset_MakeSimpleOffset(const TopoDS_Shape& theInputShape,
0069                                               const double        theOffsetValue);
0070
0071   //! Initialise shape for modifications.
0072   Standard_EXPORT void Initialize(const TopoDS_Shape& theInputShape, const double theOffsetValue);
0073
0074   //! Computes offset shape.
0075   Standard_EXPORT void Perform();
0076
0077   //! Gets error message.
0078   Standard_EXPORT TCollection_AsciiString GetErrorMessage() const;
0079
0080   //! Gets error code.
0081   BRepOffsetSimple_Status GetError() const { return myError; }
0082
0083   // Inline methods.
0084   //! Gets solid building flag.
0085   bool GetBuildSolidFlag() const { return myIsBuildSolid; }
0086
0087   //! Sets solid building flag.
0088   void SetBuildSolidFlag(const bool theBuildFlag) { myIsBuildSolid = theBuildFlag; }
0089
0090   //! Gets offset value.
0091   double GetOffsetValue() const { return myOffsetValue; }
0092
0093   //! Sets offset value.
0094   void SetOffsetValue(const double theOffsetValue) { myOffsetValue = theOffsetValue; }
0095
0096   //! Gets tolerance (used for handling singularities).
0097   double GetTolerance() const { return myTolerance; }
0098
0099   //! Sets tolerance (used for handling singularities).
0100   void SetTolerance(const double theValue) { myTolerance = theValue; }
0101
0102   //! Gets done state.
0103   bool IsDone() const { return myIsDone; }
0104
0105   //! Returns result shape.
0106   const TopoDS_Shape& GetResultShape() const { return myResShape; }
0107
0108   //! Computes max safe offset value for the given tolerance.
0109   double GetSafeOffset(const double theExpectedToler);
0110
0111   //! Returns result shape for the given one (if exists).
0112   Standard_EXPORT const TopoDS_Shape Generated(const TopoDS_Shape& theShape) const;
0113
0114   //! Returns modified shape for the given one (if exists).
0115   Standard_EXPORT const TopoDS_Shape Modified(const TopoDS_Shape& theShape) const;
0116
0117 protected:
0118   //! Computes max angle in faces junction.
0119   void ComputeMaxAngle();
0120
0121   //! Clears previous result.
0122   void Clear();
0123
0124 private:
0125   //! Builds face on specified wall.
0126   TopoDS_Face BuildWallFace(const TopoDS_Edge& theOrigEdge);
0127
0128   //! Builds missing walls.
0129   bool BuildMissingWalls();
0130
0131   // Input data.
0132
0133   //! Input shape.
0134   TopoDS_Shape myInputShape;
0135
0136   //! Offset value.
0137   double myOffsetValue;
0138
0139   //! Tolerance (for singularities)
0140   double myTolerance;
0141
0142   //! Solid building flag. True means solid construction.
0143   bool myIsBuildSolid;
0144
0145   // Internal data.
0146
0147   //! Maximal angle in faces junction. This value helps to estimate result tolerance.
0148   double myMaxAngle;
0149
0150   //! Error message.
0151   BRepOffsetSimple_Status myError;
0152
0153   //! Done state.
0154   bool myIsDone;
0155
0156   //! Map of vertex - wall edge.
0157   //! Used to build shared edge between adjacent wall faces.
0158   NCollection_DataMap<TopoDS_Vertex, TopoDS_Edge> myMapVE;
0159
0160   //! Used for histrory support.
0161   BRepTools_Modifier myBuilder;
0162
0163   //! Used for history support.
0164   occ::handle<ShapeBuild_ReShape> myReShape;
0165
0166   // Output data.
0167
0168   //! Result shape.
0169   TopoDS_Shape myResShape;
0170 };
0171
0172 #endif // _BRepOffset_MakeSimpleOffset_HeaderFile