text: // Created on: 2013-12-20
  // Created by: Denis BOGOLEPOV
  // Copyright (c) 2013-2014 OPEN CASCADE SAS
  //
  // This file is part of Open CASCADE Technology software library.
  //
  // This library is free software; you can redistribute it and/or modify it under
  // the terms of the GNU Lesser General Public License version 2.1 as published
  // by the Free Software Foundation, with special exception defined in the file
  // OCCT_LGPL_EXCEPTION.txt. Consult the file LICENSE_LGPL_21.txt included in OCCT
  // distribution for complete text of the license and disclaimer of any warranty.
  //
  // Alternatively, this file may be used under the terms of Open CASCADE
  // commercial license or contractual agreement.
  
  #ifndef BVH_PrimitiveSet_HeaderFile
  #define BVH_PrimitiveSet_HeaderFile
  
  #include <BVH_Object.hxx>
  #include <BVH_Builder.hxx>
  #include <BVH_BinnedBuilder.hxx>
  
  //! Set of abstract geometric primitives organized with bounding
  //! volume hierarchy (BVH). Unlike an object set, this collection
  //! is designed for storing structural elements of a single object
  //! (such as triangles in the object triangulation). Because there
  //! may be a large number of such elements, the implementations of
  //! this interface should be sufficiently optimized.
  //! \tparam T Numeric data type
  //! \tparam N Vector dimension
  template<class T, int N>
  class BVH_PrimitiveSet : public BVH_Object<T, N>, public BVH_Set<T, N>
  {
  protected:
  
    using BVH_Set<T, N>::Box;
  
  public:
    static const Standard_Integer MaxTreeDepth = BVH_Constants_MaxTreeDepth;
  
    //! Creates set of abstract primitives.
    BVH_PrimitiveSet()
    : myBVH (new BVH_Tree<T, N>()),
      // set default builder - binned SAH split
      myBuilder (new BVH_BinnedBuilder<T, N, BVH_Constants_NbBinsBest> (BVH_Constants_LeafNodeSizeDefault, BVH_Constants_MaxTreeDepth))
    {
      //
    }
  
    //! Creates set of abstract primitives.
    BVH_PrimitiveSet (const opencascade::handle<BVH_Builder<T, N> >& theBuilder)
    : myBVH (new BVH_Tree<T, N>()),
      myBuilder (theBuilder)
    {
      //
    }
  
    //! Releases resources of set of abstract primitives.
    virtual ~BVH_PrimitiveSet()
    {
      myBVH.Nullify();
      myBuilder.Nullify();
    }
  
  public:
  
    //! Returns AABB of primitive set.
    virtual BVH_Box<T, N> Box() const Standard_OVERRIDE
    {
      if (BVH_Object<T, N>::myIsDirty)
      {
        myBox = BVH_Set<T, N>::Box();
      }
      return myBox;
    }
  
    //! Returns BVH tree (and builds it if necessary).
    virtual const opencascade::handle<BVH_Tree<T, N> >& BVH()
    {
      if (BVH_Object<T, N>::myIsDirty)
      {
        Update();
      }
      return myBVH;
    }
  
    //! Returns the method (builder) used to construct BVH.
    virtual const opencascade::handle<BVH_Builder<T, N> >& Builder() const { return myBuilder; }
  
    //! Sets the method (builder) used to construct BVH.
    virtual void SetBuilder (const opencascade::handle<BVH_Builder<T, N> >& theBuilder) { myBuilder = theBuilder; }
  
  protected:
  
    //! Updates BVH of primitive set.
    virtual void Update()
    {
      if (BVH_Object<T, N>::myIsDirty)
      {
        myBuilder->Build (this, myBVH.operator->(), Box());
        BVH_Object<T, N>::myIsDirty = Standard_False;
      }
    }
  
  protected:
  
    opencascade::handle<BVH_Tree<T, N> >    myBVH;     //!< Constructed bottom-level BVH
    opencascade::handle<BVH_Builder<T, N> > myBuilder; //!< Builder for bottom-level BVH
  
    mutable BVH_Box<T, N> myBox; //!< Cached bounding box of geometric primitives
  
  };
  
  #endif // _BVH_PrimitiveSet_Header
  