Sample to convert Dtk_Body to OpenCascade TopoDS_Shape

Using Datakit SDK for OpenCascade needs to go through assembly and construction tree like standard integration .
Then for Dtk_Node with type Dtk_Node::BodyType you can access to the Dtk_Body and convert it into TopoDS_Shape object.
The following sample show you how to convert a Dtk_Body to an Opencascade binary object : TopoDS_Shape

 
 
 
#include "datakit.h"
#include "tess/tess.h"
#include "../LibReadersSample/WritingSample/PdfWrite/PdfWrite.hpp"
#include "../LibReadersSample/WritingSample/XmlWrite/XmlWrite.hpp"
 
 
//  for TEST OCC
//  include files of the target version of OpenCascade
#include <TopoDS_Shape.hxx>
#include <BRepTools.hxx>
//  include files of the gateway SDK-OCC
#if defined(DTK_USE_OCCRW_SDK)
#include "occrw/Dtk_SdkOcc.hpp"
#else //defined(DTK_USE_DKOC_SDK)
#include "DKOC/Dtk_SdkOcc.hpp"
#endif
 
#include <Standard_Version.hxx>
 
int GetTesselationStatus();
void WriteDtk_Mesh(const Dtk_MeshPtr& inMeshToWrite);
//extern Dtk_ErrorStatus DKOC_Body_File(const Dtk_BodyPtr& inBody, const Dtk_string& inOutputFile, const int inShapeFixMode);
extern Dtk_transfo CurrentMatrix;
 
 
static void PrintOccVersion()
{
#if defined(OCC_VERSION_COMPLETE)
     std::cout << "OpenCascade version: " << OCC_VERSION_COMPLETE << std::endl;
#elif defined(OCC_VERSION_STRING)
     std::cout << "OpenCascade version: " << OCC_VERSION_STRING << std::endl;
#elif defined(OCC_VERSION_MAJOR) && defined(OCC_VERSION_MINOR) && defined(OCC_VERSION_MAINTENANCE)
     std::cout << "OpenCascade version: "
          << OCC_VERSION_MAJOR << "."
          << OCC_VERSION_MINOR << "."
          << OCC_VERSION_MAINTENANCE << std::endl;
#else
     std::cout << "OpenCascade version macro not available in this OCC headers set." << std::endl;
#endif
}
 
 
void WriteBody(Dtk_NodePtr inNode)
{
    // Get if the node represent infinite geometry
    // 1 = Infinite, 0 = Finite
    int NodeInfiniteGeometry = inNode->GetInfos()->GetInfiniteGeometryFlag();
    if (NodeInfiniteGeometry == 0)
    {
        //Calling both methods GetDtk_MeshPtr() and GetDtk_BodyPtr() on BodyNode will give you the same result
        //Choose the one you need in order to avoid duplicated data
        const Dtk_BodyPtr TmpBody = inNode->GetDtk_BodyPtr();
        if (TmpBody.IsNotNULL())
        {
            // Used to write an XML File 
            if (IsXmlDumpActivated())
            {
                XmlWriteBody(TmpBody);
            }
 
               static bool occVersionPrinted = false;
               if( !occVersionPrinted )
               {
                    PrintOccVersion();
                    occVersionPrinted = true;
               }
 
            //  TEST  OCC
            //  For each body , write a BREP file (OCC format)
            DKOC_Body2OCCBRep B2OC;
            TopoDS_Shape res;
            B2OC.SetConfigShapeFix(DTK_TRUE);
            B2OC.SetConfigKeepPcurves(DTK_TRUE);
            Dtk_ErrorStatus stat = B2OC.ConvertBody(TmpBody);
            res = B2OC.GetMainShape();
            if (res.IsNull()) 
            {
                std::cout << "WriteBodyOcc Error : " << dtkTypeError(stat).c_str() << std::endl;
                return;
            }
 
            // Name of BREP file : with a number
            static int numbrep = 0;
            numbrep++;
 
            Dtk_InfoPtr bodyinfo = TmpBody->get_info();
            Dtk_string bodyname;
            if (bodyinfo.IsNotNULL()) bodyname = bodyinfo->GetName();
            if (bodyname.len() == 0) 
            {
                bodyinfo = inNode->GetInfos();
                if (bodyinfo.IsNotNULL()) bodyname = bodyinfo->GetName();
                if (bodyname.len() == 0) bodyname = "???";
            }
 
            std::cout << "Writing ToOpenCascade Body " << numbrep << " name: " << bodyname.c_str() << std::endl;
 
            Dtk_string filebrep = "body";
            filebrep += "_";
            filebrep.add_int(numbrep);
            filebrep += ".brep";
 
            // Write the brep file
            BRepTools::Write(res, filebrep.c_str());
 
            // How to get a TopoDS_Shape corresponding to a Dtk_Entity from its ID ( get_info()->GetId() )
            // Useful to resolve Dtk_Connector
            // This code gets the ID of the first face and then getting the corresponding TopoDS_Shape
            Dtk_LumpPtr Lump;
            Dtk_VolumePtr Vol;
            Dtk_ShellPtr Shell;
            Dtk_FacePtr Face;
            Dtk_bool orient;
            TopoDS_Shape facewithid;
            TmpBody->GetLump(0, Lump);
            if (Lump.IsNotNULL())
            {
                Lump->GetVolume(0, Vol);
                if (Vol.IsNotNULL())
                {
                    Vol->GetShell(0, Shell);
                    if (Shell.IsNotNULL())
                    {
                        Shell->GetFace(0, Face, orient);
                        if (Face.IsNotNULL())
                        {
                            Dtk_ID faceid = Face->get_info()->GetId();
                            Dtk_string SampleBrepFileForFace = "facewithid";
                            SampleBrepFileForFace.add_int(faceid);
                            SampleBrepFileForFace += ".brep";
                            facewithid = B2OC.ShapeFromDtkID(faceid);
                            BRepTools::Write(facewithid, SampleBrepFileForFace.c_str());
                        }
                    }
                }
            }
 
            // How to get the Dtk_Entity corresponding to a TopoDS_Shape
            // This code show how to retrieve Dtk_Entity form a TopoDS_Shape
               if( !facewithid.IsNull() )
               {
                    Dtk_ID DatakitFaceID = B2OC.GetDtkID( B2OC.GetShapeID( facewithid ) );
                    Dtk_tab<Dtk_EntityPtr> CorrespondingFaces;
                    Dtk_ErrorStatus err = TmpBody->GetEntities( DatakitFaceID, CorrespondingFaces );
 
                    //However, if you are looking for a Dtk_TopologialEntity, we recommand to use TmpBody->GetPtr which provides a direct access to the entity through its internal index in the Dtk_Body.
                    //To get this, you first have to construct a map from the Dtk_Body with the method FillTopologicalEntitiesIdMapping.
                    //It fills a map between Topological Entity identifiers (Dtk_ID from Dtk_Info::GetId) and the indices of corresponding entities within the Dtk_Body.
                    //While GetEntities is looking for the Dtk_Entity(s) corresponding to a Dtk_ID by browsing all the entities of the body, GetPtr is directly looking for the Dtk_TopologicalEntity pointer in the Dtk_Body using its index.
                    std::unordered_map<Dtk_ID, std::vector<Dtk_Size_t>> map;
                    TmpBody->FillTopologicalEntitiesIdMapping( map );
 
                    Dtk_tab<Dtk_TopologicalEntityPtr> CorrespondingFacesWithGetPtr;
                    if( map.count( DatakitFaceID ) > 0 )
                    {
                         for( Dtk_Size_t i = 0; i < map.at( DatakitFaceID ).size(); ++i )
                         {
                              CorrespondingFacesWithGetPtr.push_back( TmpBody->GetPtr( map.at( DatakitFaceID )[ i ] ) );
                         }
                    }
            }
 
            //  END OCC conversion
        }
    }
}