FEM: add getNodesBySolid()

Conflicts:
	src/Mod/Fem/App/FemMesh.cpp

src/Mod/Fem/App/FemMesh.cpp

@@ -524,6 +524,45 @@ std::map<int, int> FemMesh::getccxVolumesByFace(const TopoDS_Face &face) const
     return result;
 }
 
+std::set<int> FemMesh::getNodesBySolid(const TopoDS_Solid &solid) const
+{
+    std::set<int> result;
+
+    Bnd_Box box;
+    BRepBndLib::Add(solid, box);
+    // limit where the mesh node belongs to the solid:
+    double limit = box.SquareExtent()/10000.0;
+    //double limit = BRep_Tool::Tolerance(solid);   // does not compile --> no matching function for call to 'BRep_Tool::Tolerance(const TopoDS_Solid&)'
+    box.Enlarge(limit);
+
+    // get the current transform of the FemMesh
+    const Base::Matrix4D Mtrx(getTransform());
+
+    SMDS_NodeIteratorPtr aNodeIter = myMesh->GetMeshDS()->nodesIterator();
+    while (aNodeIter->more()) {
+        const SMDS_MeshNode* aNode = aNodeIter->next();
+        Base::Vector3d vec(aNode->X(),aNode->Y(),aNode->Z());
+        // Apply the matrix to hold the BoundBox in absolute space.
+        vec = Mtrx * vec;
+
+        if (!box.IsOut(gp_Pnt(vec.x,vec.y,vec.z))) {
+            // create a vertex
+            BRepBuilderAPI_MakeVertex aBuilder(gp_Pnt(vec.x,vec.y,vec.z));
+            TopoDS_Shape s = aBuilder.Vertex();
+            // measure distance
+            BRepExtrema_DistShapeShape measure(solid,s);
+            measure.Perform();
+            if (!measure.IsDone() || measure.NbSolution() < 1)
+                continue;
+
+            if (measure.Value() < limit)
+                result.insert(aNode->GetID());
+        }
+    }
+
+    return result;
+}
+
 std::set<int> FemMesh::getNodesByFace(const TopoDS_Face &face) const
 {
     std::set<int> result;