From 435cc3786de79aca689d7521a3ae9a67db8636b0 Mon Sep 17 00:00:00 2001
From: wmayer <wmayer@users.sourceforge.net>
Date: Thu, 8 Sep 2016 13:32:30 +0200
Subject: [PATCH] take care of segments in mesh on export

---
 src/Mod/Mesh/App/AppMeshPy.cpp | 47 +++++++++++++++++++++++++++++-----
 src/Mod/Mesh/App/Mesh.cpp      |  1 +
 2 files changed, 41 insertions(+), 7 deletions(-)

diff --git a/src/Mod/Mesh/App/AppMeshPy.cpp b/src/Mod/Mesh/App/AppMeshPy.cpp
index c09c29316..12ef3b188 100644
--- a/src/Mod/Mesh/App/AppMeshPy.cpp
+++ b/src/Mod/Mesh/App/AppMeshPy.cpp
@@ -59,6 +59,16 @@ using namespace MeshCore;
 namespace Mesh {
 class Module : public Py::ExtensionModule<Module>
 {
+    struct add_offset {
+        unsigned long i;
+        add_offset(unsigned long i) : i(i)
+        {
+        }
+        void operator()(unsigned long& v)
+        {
+            v += i;
+        }
+    };
 public:
     Module() : Py::ExtensionModule<Module>("Mesh")
     {
@@ -307,13 +317,36 @@ private:
                     else
                         global_mesh.addMesh(kernel);
 
-                    // now create a segment for the added mesh
-                    std::vector<unsigned long> indices;
-                    indices.resize(global_mesh.countFacets() - countFacets);
-                    std::generate(indices.begin(), indices.end(), Base::iotaGen<unsigned long>(countFacets));
-                    Segment segm(&global_mesh, indices, true);
-                    segm.setName(obj->Label.getValue());
-                    global_mesh.addSegment(segm);
+                    // if the mesh already has persistent segments then use them instead
+                    unsigned long numSegm = mesh.countSegments();
+                    unsigned long canSave = 0;
+                    for (unsigned long i=0; i<numSegm; i++) {
+                        if (mesh.getSegment(i).isSaved())
+                            canSave++;
+                    }
+
+                    if (canSave > 0) {
+                        for (unsigned long i=0; i<numSegm; i++) {
+                            const Segment& segm = mesh.getSegment(i);
+                            if (segm.isSaved()) {
+                                std::vector<unsigned long> indices = segm.getIndices();
+                                std::for_each(indices.begin(), indices.end(), add_offset(countFacets));
+                                Segment new_segm(&global_mesh, indices, true);
+                                new_segm.setName(segm.getName());
+                                global_mesh.addSegment(new_segm);
+                            }
+                        }
+
+                    }
+                    else {
+                        // now create a segment for the added mesh
+                        std::vector<unsigned long> indices;
+                        indices.resize(global_mesh.countFacets() - countFacets);
+                        std::generate(indices.begin(), indices.end(), Base::iotaGen<unsigned long>(countFacets));
+                        Segment segm(&global_mesh, indices, true);
+                        segm.setName(obj->Label.getValue());
+                        global_mesh.addSegment(segm);
+                    }
                 }
                 else if (obj->getTypeId().isDerivedFrom(partId)) {
                     App::Property* shape = obj->getPropertyByName("Shape");
diff --git a/src/Mod/Mesh/App/Mesh.cpp b/src/Mod/Mesh/App/Mesh.cpp
index c7ed5e7a3..2933068e7 100644
--- a/src/Mod/Mesh/App/Mesh.cpp
+++ b/src/Mod/Mesh/App/Mesh.cpp
@@ -1619,6 +1619,7 @@ void MeshObject::addSegment(const Segment& s)
     addSegment(s.getIndices());
     this->_segments.back().setName(s.getName());
     this->_segments.back().save(s.isSaved());
+    this->_segments.back()._modifykernel = s._modifykernel;
 }
 
 void MeshObject::addSegment(const std::vector<unsigned long>& inds)