1 // Created on: 1993-07-22 2 // Created by: Isabelle GRIGNON 3 // Copyright (c) 1993-1999 Matra Datavision 4 // Copyright (c) 1999-2014 OPEN CASCADE SAS 5 // 6 // This file is part of Open CASCADE Technology software library. 7 // 8 // This library is free software; you can redistribute it and/or modify it under 9 // the terms of the GNU Lesser General Public License version 2.1 as published 10 // by the Free Software Foundation, with special exception defined in the file 11 // OCCT_LGPL_EXCEPTION.txt. Consult the file LICENSE_LGPL_21.txt included in OCCT 12 // distribution for complete text of the license and disclaimer of any warranty. 13 // 14 // Alternatively, this file may be used under the terms of Open CASCADE 15 // commercial license or contractual agreement. 16 17 #ifndef _BRepBndLib_HeaderFile 18 #define _BRepBndLib_HeaderFile 19 20 #include <Standard.hxx> 21 #include <Standard_DefineAlloc.hxx> 22 #include <Standard_Handle.hxx> 23 24 #include <Standard_Boolean.hxx> 25 class TopoDS_Shape; 26 class Bnd_Box; 27 class Bnd_OBB; 28 29 30 //! This package provides the bounding boxes for curves 31 //! and surfaces from BRepAdaptor. 32 //! Functions to add a topological shape to a bounding box 33 class BRepBndLib 34 { 35 public: 36 37 DEFINE_STANDARD_ALLOC 38 39 40 //! Adds the shape S to the bounding box B. 41 //! More precisely are successively added to B: 42 //! - each face of S; the triangulation of the face is used if it exists, 43 //! - then each edge of S which does not belong to a face, 44 //! the polygon of the edge is used if it exists 45 //! - and last each vertex of S which does not belong to an edge. 46 //! After each elementary operation, the bounding box B is 47 //! enlarged by the tolerance value of the relative sub-shape. 48 //! When working with the triangulation of a face this value of 49 //! enlargement is the sum of the triangulation deflection and 50 //! the face tolerance. When working with the 51 //! polygon of an edge this value of enlargement is 52 //! the sum of the polygon deflection and the edge tolerance. 53 //! Warning 54 //! - This algorithm is time consuming if triangulation has not 55 //! been inserted inside the data structure of the shape S. 56 //! - The resulting bounding box may be somewhat larger than the object. 57 Standard_EXPORT static void Add (const TopoDS_Shape& S, Bnd_Box& B, const Standard_Boolean useTriangulation = Standard_True); 58 59 //! Adds the shape S to the bounding box B. 60 //! This is a quick algorithm but only works if the shape S is 61 //! composed of polygonal planar faces, as is the case if S is 62 //! an approached polyhedral representation of an exact 63 //! shape. Pay particular attention to this because this 64 //! condition is not checked and, if it not respected, an error 65 //! may occur in the algorithm for which the bounding box is built. 66 //! Note that the resulting bounding box is not enlarged by the 67 //! tolerance value of the sub-shapes as is the case with the 68 //! Add function. So the added part of the resulting bounding 69 //! box is closer to the shape S. 70 Standard_EXPORT static void AddClose (const TopoDS_Shape& S, Bnd_Box& B); 71 72 //! Adds the shape S to the bounding box B. 73 //! This algorith builds precise bounding box, 74 //! which differs from exact geometry boundaries of shape only on shape entities tolerances 75 //! Algorithm is the same as for method Add(..), but uses more precise methods for building boxes 76 //! for geometry objects. 77 //! If useShapeTolerance = True, bounding box is enlardged by shape tolerances and 78 //! these tolerances are used for numerical methods of bounding box size calculations, 79 //! otherwise bounding box is built according to sizes of uderlined geometrical entities, 80 //! numerical calculation use tolerance Precision::Confusion(). 81 Standard_EXPORT static void AddOptimal (const TopoDS_Shape& S, Bnd_Box& B, 82 const Standard_Boolean useTriangulation = Standard_True, 83 const Standard_Boolean useShapeTolerance = Standard_False); 84 85 86 //! Computes the Oriented Bounding box for the shape <theS>. 87 //! Two independent methods of computation are implemented: 88 //! first method based on set of points (so, it demands the 89 //! triangulated shape or shape with planar faces and linear edges). 90 //! The second method is based on use of inertia axes and is called 91 //! if use of the first method is impossible. 92 //! If theIsTriangulationUsed == FALSE then the triangulation will 93 //! be ignored at all. 94 //! If theIsShapeToleranceUsed == TRUE then resulting box will be 95 //! extended on the tolerance of the shape. 96 //! theIsOptimal flag defines whether to look for the more tight 97 //! OBB for the cost of performance or not. 98 Standard_EXPORT static 99 void AddOBB(const TopoDS_Shape& theS, 100 Bnd_OBB& theOBB, 101 const Standard_Boolean theIsTriangulationUsed = Standard_True, 102 const Standard_Boolean theIsOptimal = Standard_False, 103 const Standard_Boolean theIsShapeToleranceUsed = Standard_True); 104 105 protected: 106 107 108 109 110 111 private: 112 113 114 115 116 117 }; 118 119 120 121 122 123 124 125 #endif // _BRepBndLib_HeaderFile 126