include/opencascade/BVH_Distance.hxx

0001 // Created by: Eugeny MALTCHIKOV
0002 // Created on: 2019-04-17
0003 // Copyright (c) 2019 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 _BVH_Distance_Header
0017 #define _BVH_Distance_Header
0018
0019 #include <BVH_Traverse.hxx>
0020
0021 //! Abstract class for computation of the min distance between some
0022 //! Object and elements of BVH tree.
0023 //! To use this class it is required to define two methods:
0024 //! - *RejectNode* to compute distance from the object to bounding box
0025 //! - *Accept* to compute distance from the object to the element of tree
0026 //!
0027 //! \tparam NumType Numeric data type
0028 //! \tparam Dimension Vector dimension
0029 //! \tparam ObjectType Type of the object to which the distance is required
0030 //! \tparam BVHSetType Type of the set on which BVH is built
0031 template <class NumType, int Dimension, class ObjectType, class BVHSetType>
0032 class BVH_Distance : public BVH_Traverse<NumType, Dimension, BVHSetType, NumType>
0033 {
0034 public: //! @name Constructor
0035
0036   //! Constructor
0037   BVH_Distance()
0038     : BVH_Traverse <NumType, Dimension, BVHSetType, NumType>(),
0039       myDistance (std::numeric_limits<NumType>::max()),
0040       myIsDone(Standard_False)
0041   {
0042   }
0043
0044 public: //! @name Setting object for distance computation
0045
0046   //! Sets the object to which the distance is required
0047   void SetObject (const ObjectType& theObject)
0048   {
0049     myObject = theObject;
0050   }
0051
0052 public: //! @name Compute the distance
0053
0054   //! Computes the distance between object and BVH tree
0055   NumType ComputeDistance()
0056   {
0057     myIsDone = this->Select() > 0;
0058     return myDistance;
0059   }
0060
0061 public: //! @name Accessing the results
0062
0063   //! Returns IsDone flag
0064   Standard_Boolean IsDone () const { return myIsDone; }
0065
0066   //! Returns the computed distance
0067   NumType Distance() const { return myDistance; }
0068
0069 public: //! @name Definition of the rules for tree descend
0070
0071   //! Compares the two metrics and chooses the best one
0072   virtual Standard_Boolean IsMetricBetter (const NumType& theLeft,
0073                                            const NumType& theRight) const Standard_OVERRIDE
0074   {
0075     return theLeft < theRight;
0076   }
0077
0078   //! Rejects the branch by the metric
0079   virtual Standard_Boolean RejectMetric (const NumType& theMetric) const Standard_OVERRIDE
0080   {
0081     return theMetric > myDistance;
0082   }
0083
0084   //! Returns the flag controlling the tree descend
0085   virtual Standard_Boolean Stop() const Standard_OVERRIDE
0086   {
0087     return myDistance == static_cast<NumType>(0);
0088   }
0089
0090 protected: //! @name Fields
0091
0092   NumType myDistance;        //!< Distance
0093   Standard_Boolean myIsDone; //!< State of the algorithm
0094   ObjectType myObject;       //!< Object to compute the distance to
0095
0096 };
0097
0098 #endif // _BVH_Distance_Header