OCCT: port FreeCAD sources to version 7.6

SMESH is not yet ported
Although FreeCAD code compiles with OCCT 7.6 it doesn't work at the moment

src/Mod/Part/Gui/ViewProviderExt.cpp

@@ -1083,16 +1083,25 @@ void ViewProviderPartExt::updateVisual()
 
 
             // cycling through the poly mesh
+#if OCC_VERSION_HEX < 0x070600
             const Poly_Array1OfTriangle& Triangles = mesh->Triangles();
             const TColgp_Array1OfPnt& Nodes = mesh->Nodes();
             TColgp_Array1OfDir Normals (Nodes.Lower(), Nodes.Upper());
+#else
+            int numNodes =  mesh->NbNodes();
+            TColgp_Array1OfDir Normals (1, numNodes);
+#endif
             if (NormalsFromUV)
                 Part::Tools::getPointNormals(actFace, mesh, Normals);
             
             for (int g=1;g<=nbTriInFace;g++) {
                 // Get the triangle
                 Standard_Integer N1,N2,N3;
+#if OCC_VERSION_HEX < 0x070600
                 Triangles(g).Get(N1,N2,N3);
+#else
+                mesh->Triangle(g).Get(N1,N2,N3);
+#endif
 
                 // change orientation of the triangle if the face is reversed
                 if ( orient != TopAbs_FORWARD ) {
@@ -1102,7 +1111,11 @@ void ViewProviderPartExt::updateVisual()
                 }
 
                 // get the 3 points of this triangle
+#if OCC_VERSION_HEX < 0x070600
                 gp_Pnt V1(Nodes(N1)), V2(Nodes(N2)), V3(Nodes(N3));
+#else
+                gp_Pnt V1(mesh->Node(N1)), V2(mesh->Node(N2)), V3(mesh->Node(N3));
+#endif
 
                 // get the 3 normals of this triangle
                 gp_Vec NV1, NV2, NV3;
@@ -1179,7 +1192,11 @@ void ViewProviderPartExt::updateVisual()
                         // rare cases where some points are only referenced by the polygon
                         // but not by any triangle. Thus, we must apply the coordinates to
                         // make sure that everything is properly set.
+#if OCC_VERSION_HEX < 0x070600
                         gp_Pnt p(Nodes(nodeIndex));
+#else
+                        gp_Pnt p(mesh->Node(nodeIndex));
+#endif
                         if (!identity)
                             p.Transform(myTransf);
                         verts[index].setValue((float)(p.X()),(float)(p.Y()),(float)(p.Z()));