// Created on: 2011-10-14 
// Created by: Roman KOZLOV
// Copyright (c) 2011-2014 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 __IVTKOCC_SHAPEMESHER_H__
#define __IVTKOCC_SHAPEMESHER_H__

#include <BRepAdaptor_HSurface.hxx>
#include <IVtkOCC_Shape.hxx>
#include <IVtk_IShapeMesher.hxx>
#include <TColgp_Array1OfPnt.hxx>
#include <TColgp_SequenceOfPnt.hxx>
#include <TColStd_Array1OfInteger.hxx>
#include <TopoDS.hxx>
#include <TopoDS_Edge.hxx>
#include <TopoDS_Face.hxx>
#include <TopoDS_Vertex.hxx>
#include <TopTools_IndexedDataMapOfShapeListOfShape.hxx>
#include <TopTools_ListOfShape.hxx>
#include <TopTools_ShapeMapHasher.hxx>

typedef NCollection_DataMap <TopoDS_Shape, IVtk_MeshType, TopTools_ShapeMapHasher> IVtk_ShapeTypeMap;
typedef NCollection_Sequence <gp_Pnt> IVtk_Polyline;
typedef NCollection_List <IVtk_Polyline> IVtk_PolylineList;

class IVtkOCC_ShapeMesher;
DEFINE_STANDARD_HANDLE( IVtkOCC_ShapeMesher, IVtk_IShapeMesher )

//! @class IVtkOCC_ShapeMesher 
//! @brief OCC implementation of IMesher interface.
//!
//! Mesher produces shape data using implementation of IShapeData interface for
//! VTK and then result can be retrieved from this implementation as a vtkPolyData:
//! @image html doc/img/image002.gif
//! Then the resulting vtkPolyData can be used for initialization of VTK pipeline.
class IVtkOCC_ShapeMesher : public IVtk_IShapeMesher
{
public:
  IVtkOCC_ShapeMesher (const Standard_Real& theDevCoeff = 0.0001,
                       const Standard_Real& theDevAngle = 12.0 * M_PI / 180.0,
                       const Standard_Integer theNbUIsos = 1,
                       const Standard_Integer theNbVIsos = 1)
 : myDevCoeff (theDevCoeff),
   myDevAngle (theDevAngle),
   myDeflection (0.0)
  {
    myNbIsos[0] = theNbUIsos;
    myNbIsos[1] = theNbVIsos;
  }

  virtual ~IVtkOCC_ShapeMesher() { }

  //! Returns absolute deflection used by this algorithm.
  //! This value is calculated on the basis of the shape's bounding box.
  //! Zero might be returned in case if the underlying OCCT shape 
  //! is empty or invalid. Thus check the returned value before
  //! passing it to OCCT meshing algorithms!
  //! @return absolute deflection value
  Standard_EXPORT Standard_Real GetDeflection() const;

  //! Returns relative deviation coefficient used by this algorithm.
  //! @return relative deviation coefficient
  Standard_Real GetDeviationCoeff() const
  {
    return myDevCoeff;
  }

  //! Returns deviation angle used by this algorithm.
  //! This is the maximum allowed angle between the normals to the 
  //! curve/surface and the normals to polyline/faceted representation.
  //! @return deviation angle (in radians)
  Standard_Real GetDeviationAngle() const
  {
    return myDevAngle;
  }

protected:
  //! Executes the mesh generation algorithms. To be defined in implementation class.
  Standard_EXPORT virtual void internalBuild() Standard_OVERRIDE;

private:
  //! Internal method, generates OCCT triangulation starting from TopoDS_Shape
  //! @see IVtkOCC_ShapeMesher::addEdge, IVtkOCC_ShapeMesher::addShadedFace
  void meshShape();

  //! Extracts free vertices from the shape (i.e. those not belonging to any edge)
  //! and passes the geometry to IPolyData. 
  //! Each vertex is associated with its sub-shape ID.
  void addFreeVertices();

  //! Adds all the edges (free and non-free) to IPolyData.
  void addEdges();

  //! Adds wireframe representations of all faces to IPolyData.
  void addWireFrameFaces();

  //! Adds shaded representations of all faces to IPolyData.
  void addShadedFaces();

  //! Adds the point coordinates, connectivity info and
  //! sub-shape ID for the OCCT vertex.
  //!
  //! @param theVertex OCCT vertex to be added to the mesh
  //! @param theShapeId global point ID needed for connectivity data creation
  void addVertex (const TopoDS_Vertex& theVertex,
                  const IVtk_IdType    theShapeId,
                  const IVtk_MeshType  theMeshType);

  //! Adds the point coordinates and a polyline for the OCCT edge.
  //! Note that the edge should be triangulated in advance.
  //!
  //! @param theEdge OCCT edge to be meshed
  //! @param theShapeId the edge's subshape ID
  //! @see IVtkOCC_ShapeMesher::meshShape
  void addEdge (const TopoDS_Edge&   theEdge,
                const IVtk_IdType    theShapeId,
                const IVtk_MeshType  theMeshType);

  //! Generates wireframe representation of the given TopoDS_Face object
  //! with help of OCCT algorithms. The resulting polylines are passed to IPolyData
  //! interface and associated with the given sub-shape ID.
  //! @param [in] faceToMesh TopoDS_Face object to build wireframe representation for.
  //! @param [in] shapeId The face' sub-shape ID 
  void addWFFace (const TopoDS_Face&   theFace,
                  const IVtk_IdType    theShapeId);

  //! Creates shaded representation of the given TopoDS_Face object
  //! starting from OCCT triangulation that should be created in advance. 
  //! The resulting triangles are passed to IPolyData
  //! interface and associated with the given sub-shape ID.
  //! @param [in] faceToMesh TopoDS_Face object to build shaded representation for.
  //! @param [in] shapeId The face' sub-shape ID
  //! @see IVtkOCC_ShapeMesher::meshShape, IVtkOCC_ShapeMesher::addEdge
  void addShadedFace (const TopoDS_Face&   theFace,
                      const IVtk_IdType    theShapeId);

  //! Internal helper method that unpacks the input arrays of points and 
  //! connectivity and creates the polyline using IPolyData interface.
  //! Optionally, the transformation specified through the last argument
  //! can be applied to each point's coordinates (noTransform == true).
  //! The polyline is associated with the given sub-shape ID.
  void processPolyline (Standard_Integer               theNbNodes,
                        const TColgp_Array1OfPnt&      thePoints,
                        const TColStd_Array1OfInteger& thePointIds, 
                        const IVtk_IdType              theOcctId,
                        bool                           theNoTransform,
                        gp_Trsf                        theTransformation,
                        const IVtk_MeshType            theMeshType);

  //! Get the IShape as OCC implementation
  const IVtkOCC_Shape::Handle GetShapeObj() const;

  DEFINE_STANDARD_RTTIEXT(IVtkOCC_ShapeMesher,IVtk_IShapeMesher)

private:
  IVtk_ShapeTypeMap     myEdgesTypes;
  Standard_Real         myDevCoeff;
  Standard_Real         myDevAngle;
  mutable Standard_Real myDeflection;
  Standard_Integer      myNbIsos[2];
};

#endif //  __IVTKOCC_SHAPEMESHER_H__
