OCCT

// Created on: 2016-07-04
// Copyright (c) 2016 OPEN CASCADE SAS
// Created by: Oleg AGASHIN
//
// 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.

#include <BRepMesh_ModelPostProcessor.hxx>

#include <BRepMesh_ShapeTool.hxx>
#include <IMeshData_Model.hxx>
#include <IMeshData_Edge.hxx>
#include <IMeshData_PCurve.hxx>
#include <IMeshTools_Parameters.hxx>
#include <OSD_Parallel.hxx>
#include <BRepLib.hxx>
#include <Poly_TriangulationParameters.hxx>

IMPLEMENT_STANDARD_RTTIEXT(BRepMesh_ModelPostProcessor, IMeshTools_ModelAlgo)

namespace
{
//! Commits 3D polygons and polygons on triangulations for corresponding edges.
class PolygonCommitter
{
public:
  //! Constructor
  PolygonCommitter(const occ::handle<IMeshData_Model>& theModel)
      : myModel(theModel)
  {
  }

  //! Main functor.
  void operator()(const int theEdgeIndex) const
  {
    const IMeshData::IEdgeHandle& aDEdge = myModel->GetEdge(theEdgeIndex);
    if (aDEdge->GetCurve()->ParametersNb() == 0)
    {
      return;
    }

    if (aDEdge->IsFree())
    {
      if (!aDEdge->IsSet(IMeshData_Reused))
      {
        commitPolygon3D(aDEdge);
      }
    }
    else
    {
      commitPolygons(aDEdge);
    }
  }

private:
  //! Commits 3d polygon to topological edge
  void commitPolygon3D(const IMeshData::IEdgeHandle& theDEdge) const
  {
    const IMeshData::ICurveHandle& aCurve = theDEdge->GetCurve();

    NCollection_Array1<gp_Pnt> aNodes(1, aCurve->ParametersNb());
    NCollection_Array1<double> aUVNodes(1, aCurve->ParametersNb());
    for (int i = 1; i <= aCurve->ParametersNb(); ++i)
    {
      aNodes(i)   = aCurve->GetPoint(i - 1);
      aUVNodes(i) = aCurve->GetParameter(i - 1);
    }

    occ::handle<Poly_Polygon3D> aPoly3D = new Poly_Polygon3D(aNodes, aUVNodes);
    aPoly3D->Deflection(theDEdge->GetDeflection());

    BRepMesh_ShapeTool::UpdateEdge(theDEdge->GetEdge(), aPoly3D);
  }

  //! Commits all polygons on triangulations correspondent to the given edge.
  void commitPolygons(const IMeshData::IEdgeHandle& theDEdge) const
  {
    // Collect pcurves associated with the given edge on the specific surface.
    IMeshData::IDMapOfIFacePtrsListOfIPCurves aMapOfPCurves;
    for (int aPCurveIt = 0; aPCurveIt < theDEdge->PCurvesNb(); ++aPCurveIt)
    {
      const IMeshData::IPCurveHandle& aPCurve   = theDEdge->GetPCurve(aPCurveIt);
      const IMeshData::IFacePtr&      aDFacePtr = aPCurve->GetFace();
      const IMeshData::IFaceHandle    aDFace    = aDFacePtr;
      if (aDFace->IsSet(IMeshData_Failure) || aDFace->IsSet(IMeshData_Reused))
      {
        continue;
      }

      if (!aMapOfPCurves.Contains(aDFacePtr))
      {
        aMapOfPCurves.Add(aDFacePtr, IMeshData::ListOfIPCurves());
      }

      IMeshData::ListOfIPCurves& aPCurves = aMapOfPCurves.ChangeFromKey(aDFacePtr);
      aPCurves.Append(aPCurve);
    }

    // Commit polygons related to separate face.
    const TopoDS_Edge&                                  aEdge = theDEdge->GetEdge();
    IMeshData::IDMapOfIFacePtrsListOfIPCurves::Iterator aPolygonIt(aMapOfPCurves);
    for (; aPolygonIt.More(); aPolygonIt.Next())
    {
      const TopoDS_Face& aFace = aPolygonIt.Key()->GetFace();

      TopLoc_Location                        aLoc;
      const occ::handle<Poly_Triangulation>& aTriangulation = BRep_Tool::Triangulation(aFace, aLoc);

      if (!aTriangulation.IsNull())
      {
        const IMeshData::ListOfIPCurves& aPCurves = aPolygonIt.Value();
        if (aPCurves.Size() == 2)
        {
          BRepMesh_ShapeTool::UpdateEdge(
            aEdge,
            collectPolygon(aPCurves.First(), theDEdge->GetDeflection()),
            collectPolygon(aPCurves.Last(), theDEdge->GetDeflection()),
            aTriangulation,
            aLoc);
        }
        else
        {
          BRepMesh_ShapeTool::UpdateEdge(
            aEdge,
            collectPolygon(aPCurves.First(), theDEdge->GetDeflection()),
            aTriangulation,
            aLoc);
        }
      }
    }
  }

  //! Collects polygonal data for the given pcurve
  occ::handle<Poly_PolygonOnTriangulation> collectPolygon(const IMeshData::IPCurveHandle& thePCurve,
                                                          const double theDeflection) const
  {
    NCollection_Array1<int>    aNodes(1, thePCurve->ParametersNb());
    NCollection_Array1<double> aParams(1, thePCurve->ParametersNb());
    for (int i = 1; i <= thePCurve->ParametersNb(); ++i)
    {
      aNodes(i)  = thePCurve->GetIndex(i - 1);
      aParams(i) = thePCurve->GetParameter(i - 1);
    }

    occ::handle<Poly_PolygonOnTriangulation> aPolygon =
      new Poly_PolygonOnTriangulation(aNodes, aParams);

    aPolygon->Deflection(theDeflection);
    return aPolygon;
  }

private:
  occ::handle<IMeshData_Model> myModel;
};

//! Estimates and updates deflection of triangulations for corresponding faces.
class DeflectionEstimator
{
public:
  //! Constructor
  DeflectionEstimator(const occ::handle<IMeshData_Model>& theModel,
                      const IMeshTools_Parameters&        theParams)
      : myModel(theModel),
        myParams(new Poly_TriangulationParameters(theParams.Deflection,
                                                  theParams.Angle,
                                                  theParams.MinSize))
  {
  }

  //! Main functor.
  void operator()(const int theFaceIndex) const
  {
    const IMeshData::IFaceHandle& aDFace = myModel->GetFace(theFaceIndex);
    if (aDFace->IsSet(IMeshData_Failure) || aDFace->IsSet(IMeshData_Reused))
    {
      return;
    }

    BRepLib::UpdateDeflection(aDFace->GetFace());

    TopLoc_Location                        aLoc;
    const occ::handle<Poly_Triangulation>& aTriangulation =
      BRep_Tool::Triangulation(aDFace->GetFace(), aLoc);

    if (!aTriangulation.IsNull())
    {
      aTriangulation->Parameters(myParams);
    }
  }

private:
  occ::handle<IMeshData_Model>              myModel;
  occ::handle<Poly_TriangulationParameters> myParams;
};
} // namespace

//=================================================================================================

BRepMesh_ModelPostProcessor::BRepMesh_ModelPostProcessor() = default;

//=================================================================================================

BRepMesh_ModelPostProcessor::~BRepMesh_ModelPostProcessor() = default;

//=================================================================================================

bool BRepMesh_ModelPostProcessor::performInternal(const occ::handle<IMeshData_Model>& theModel,
                                                  const IMeshTools_Parameters&        theParameters,
                                                  const Message_ProgressRange&        theRange)
{
  (void)theRange;
  if (theModel.IsNull())
  {
    return false;
  }

  // TODO: Force single threaded solution due to data races on edges sharing the same TShape
  OSD_Parallel::For(0,
                    theModel->EdgesNb(),
                    PolygonCommitter(theModel),
                    true /*!theParameters.InParallel*/);

  // Estimate deflection here due to BRepLib::EstimateDeflection requires
  // existence of both Poly_Triangulation and Poly_PolygonOnTriangulation.
  OSD_Parallel::For(0,
                    theModel->FacesNb(),
                    DeflectionEstimator(theModel, theParameters),
                    !theParameters.InParallel);
  return true;
}