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 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
#include "DKOC/Dtk_SdkOcc.hpp"
 
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;
 
 
 
 
 
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);
            }
 
            //  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 = bodyname;
            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_EntityPtr CorrespondingFace = TmpBody->GetEntity(DatakitFaceID);
            }
 
            //  END OCC conversion
        }
 
        // Some CAD formats store also faceted data besides B-Rep. 
        // So you can get faceted data corresponding to the body using the following method
        const Dtk_MeshPtr TmpFacetedBody = inNode->GetDtk_MeshPtr();
        if (TmpFacetedBody.IsNotNULL())
        {
            TmpFacetedBody->Transform(CurrentMatrix);
            WriteDtk_Mesh(TmpFacetedBody);
        }
 
 
        // If there is no mesh data associated to the current body, you can tessellate (and if init of tessellation engine is successful)
        if (TmpFacetedBody.IsNULL() && TmpBody.IsNotNULL() && GetTesselationStatus() == dtkNoError)
        {
            Dtk_tab<Dtk_MeshPtr> meshes;
            Dtk_tab<Dtk_Int32> isclosed;
            int err_tess = tess_BodyToMeshes(TmpBody, meshes, isclosed);
               if( inNode->Name().len() > 0 )
                    std::cout << "NodeName = " << inNode->Name().c_str() << ";";
            std::cout << "err_tess = " << dtkTypeError( err_tess ).c_str() << std::endl ;
            if (err_tess == 0)
            {
                Dtk_Size_t i, nbmeshes = meshes.size();
                for (i = 0; i < nbmeshes; i++)
                {
                    meshes[i]->Transform(CurrentMatrix);
                    WriteDtk_Mesh(meshes[i]);
                }
            }
 
            if (IsPdfDumpActivated() && TmpBody->HasWire())
            {// handling wire / points
                    PdfWriteEntity( Dtk_EntityPtr::DtkDynamicCast( TmpBody ));
            }
        }
    }
}