fix compile without rtree

Mesh/filterElements.cpp

+// Gmsh - Copyright (C) 1997-2013 C. Geuzaine, J.-F. Remacle
+//
+// See the LICENSE.txt file for license information. Please report all
+// bugs and problems to the public mailing list <gmsh@geuz.org>.
+
 #include <algorithm>
 #include <vector>
 #include <set>
@@ -10,6 +15,7 @@
 #include "MQuadrangle.h"
 #include "MPrism.h"
 #include "MHexahedron.h"
+
 #if defined(HAVE_RTREE)
 #include "rtree.h"
 void MElementBB(void *a, double *min, double *max);
@@ -37,12 +43,13 @@ static bool inBB (double *mi, double *ma, double *x){
   return true;
 }
 
-bool rtree_callback(MElement *e1,void* pe2){
+bool rtree_callback(MElement *e1,void* pe2)
+{
   MElement_Wrapper *wrapper = static_cast<MElement_Wrapper*>(pe2);
   MElement *e2 = wrapper->_e;
 
-  if (std::binary_search(wrapper->_notOverlap.begin(),wrapper->_notOverlap.end(),e1))return true;  
-  
+  if (std::binary_search(wrapper->_notOverlap.begin(),wrapper->_notOverlap.end(),e1))
+    return true;
 
   for (int i=0;i<e1->getNumVertices();i++){
     for (int j=0;j<e2->getNumVertices();j++){
@@ -213,11 +220,30 @@ void filterOverlappingElements (std::vector<MElement*> &els,
   }
   els = newEls;
 }
+
 #else
+
+void filterOverlappingElements (std::vector<MTriangle*> &blTris,
+				std::vector<MQuadrangle*>&blQuads,
+				std::map<MElement*,std::vector<MElement*> > &_elemColumns,
+				std::map<MElement*,MElement*> &_toFirst)
+{
+  Msg::Error("Gmsh needs to be compiled with RTREE support for bonudary layers");
+}
+
+void filterOverlappingElements (std::vector<MPrism*> &blPrisms,
+				std::vector<MHexahedron*>&blHexes,
+				std::map<MElement*,std::vector<MElement*> > &_elemColumns,
+				std::map<MElement*,MElement*> &_toFirst)
+{
+  Msg::Error("Gmsh needs to be compiled with RTREE support for bonudary layers");
+}
+
 void filterOverlappingElements (std::vector<MElement*> &els,
 				std::map<MElement*,std::vector<MElement*> > &_elemColumns,
 				std::map<MElement*,MElement*> &_toFirst )
 {
-  Msg::Error("full boundary layer capabilities are only available whilst compiling GMSH together with a RTREE library");
+  Msg::Error("Gmsh needs to be compiled with RTREE support for bonudary layers");
 }
+
 #endif