include/opencascade/GProp.hxx

0001 // Created on: 1991-03-12
0002 // Created by: Michel CHAUVAT
0003 // Copyright (c) 1991-1999 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 _GProp_HeaderFile
0018 #define _GProp_HeaderFile
0019
0020 #include <Standard.hxx>
0021 #include <Standard_DefineAlloc.hxx>
0022 #include <Standard_Handle.hxx>
0023
0024 #include <Standard_Real.hxx>
0025 class gp_Pnt;
0026 class gp_Mat;
0027
0028 //! This package defines algorithms to compute the global properties
0029 //! of a set of points, a curve, a surface, a solid (non infinite
0030 //! region of space delimited with geometric entities), a compound
0031 //! geometric system (heterogeneous composition of the previous
0032 //! entities).
0033 //!
0034 //! Global properties are:
0035 //! . length, area, volume,
0036 //! . centre of mass,
0037 //! . axis of inertia,
0038 //! . moments of inertia,
0039 //! . radius of gyration.
0040 //!
0041 //! It provides also a class to compile the average point or
0042 //! line of a set of points.
0043 class GProp
0044 {
0045 public:
0046   DEFINE_STANDARD_ALLOC
0047
0048   //! methods of package
0049   //! Computes the matrix Operator, referred to as the
0050   //! "Huyghens Operator" of a geometric system at the
0051   //! point Q of the space, using the following data:
0052   //! - Mass, i.e. the mass of the system,
0053   //! - G, the center of mass of the system.
0054   //! The "Huyghens Operator" is used to compute
0055   //! Inertia/Q, the matrix of inertia of the system at
0056   //! the point Q using Huyghens' theorem:
0057   //! Inertia/Q = Inertia/G + HOperator (Q, G, Mass)
0058   //! where Inertia/G is the matrix of inertia of the
0059   //! system relative to its center of mass as returned by
0060   //! the function MatrixOfInertia on any GProp_GProps object.
0061   Standard_EXPORT static void HOperator(const gp_Pnt& G,
0062                                         const gp_Pnt& Q,
0063                                         const double  Mass,
0064                                         gp_Mat&       Operator);
0065 };
0066
0067 #endif // _GProp_HeaderFile