From 9a239261bb9b0c33db27666c6095dacc5eaf638d Mon Sep 17 00:00:00 2001
From: jriegel <FreeCAD@juergen-riegel.net>
Date: Mon, 2 Dec 2013 20:35:12 +0100
Subject: [PATCH] fix in get visible faces

---
 src/Mod/Fem/Gui/ViewProviderFemMeshPyImp.cpp | 28 ++++++++++++++++----
 1 file changed, 23 insertions(+), 5 deletions(-)

diff --git a/src/Mod/Fem/Gui/ViewProviderFemMeshPyImp.cpp b/src/Mod/Fem/Gui/ViewProviderFemMeshPyImp.cpp
index e19204b6c..8a18f6e06 100644
--- a/src/Mod/Fem/Gui/ViewProviderFemMeshPyImp.cpp
+++ b/src/Mod/Fem/Gui/ViewProviderFemMeshPyImp.cpp
@@ -103,14 +103,32 @@ void  ViewProviderFemMeshPy::setHighlightedNodes(Py::List arg)
 Py::List ViewProviderFemMeshPy::getVisibleElementFaces(void) const
 {
     const std::vector<unsigned long> & visElmFc = this->getViewProviderFemMeshPtr()->getVisibleElementFaces();
-    Py::List result( visElmFc.size() );
+    std::vector<unsigned long> trans;
 
+    // sorting out double faces through higer order elements and null entries
+    long elementOld =0, faceOld=0;
+    for (std::vector<unsigned long>::const_iterator it = visElmFc.begin();it!=visElmFc.end();++it){
+        if(*it == 0)
+            continue;
+
+        long element = *it>>3;
+        long face    = (*it&7)+1;
+        if(element == elementOld && face==faceOld)
+            continue;
+
+        trans.push_back(*it);
+        elementOld = element;
+        faceOld    = face;
+    }
+
+    Py::List result( trans.size() );
     int i = 0;
-    for (std::vector<unsigned long>::const_iterator it = visElmFc.begin();it!=visElmFc.end();++it,i++){
+    for (std::vector<unsigned long>::const_iterator it = trans.begin();it!=trans.end();++it,i++){
         Py::Tuple tup(2);
-
-        tup.setItem( 0,Py::Int((long)*it>>3) );
-        tup.setItem( 1,Py::Int((long)(*it&7)+1) );
+        long element = *it>>3;
+        long face    = (*it&7)+1;
+        tup.setItem( 0,Py::Int( element ) );
+        tup.setItem( 1,Py::Int( face ) );
         result.setItem(i,tup);
     }