add observer pattern to all decimaters

closes #2366

git-svn-id: http://www.openmesh.org/svnrepo/OpenMesh/trunk@1197 fdac6126-5c0c-442c-9429-916003d36597

src/OpenMesh/Tools/Decimater/BaseDecimaterT.cc

@@ -67,7 +67,7 @@ namespace Decimater {
 
 template<class Mesh>
 BaseDecimaterT<Mesh>::BaseDecimaterT(Mesh& _mesh) :
-    mesh_(_mesh), cmodule_(NULL), initialized_(false) {
+    mesh_(_mesh), cmodule_(NULL), initialized_(false), observer_(NULL) {
   // default properties
   mesh_.request_vertex_status();
   mesh_.request_edge_status();

src/OpenMesh/Tools/Decimater/BaseDecimaterT.hh

@@ -71,6 +71,30 @@ namespace Decimater {
 //== CLASS DEFINITION =========================================================
 
 
+class Observer
+{
+public:
+  Observer(size_t _step) :
+      step_(_step) {
+  }
+  
+  virtual ~Observer() {
+  }
+  
+  size_t get_step() const                 { return step_; }
+  // give the notification step size
+  void set_step(size_t _step)         { step_ = _step; }
+  
+  //notifies about a finished decimater step with the given step number
+  virtual void notify(size_t _step) = 0;
+  //after notification, ask for abort or not, return true, if the decimater should abort
+  virtual bool abort() const = 0;
+  
+private:
+  size_t step_;
+};
+
+
 /** base class decimater framework
     \see BaseDecimaterT, \ref decimater_docu
 */
@@ -113,6 +137,17 @@ public: //------------------------------------------------------ public methods
 
 public: //--------------------------------------------------- module management
 
+  // Observer interface
+  void set_observer(Observer* _o)
+  {
+      observer_ = _o;
+  }
+
+  Observer* observer()
+  {
+      return observer_;
+  }
+
   /// access mesh. used in modules.
   Mesh& mesh() { return mesh_; }
 
@@ -166,6 +201,17 @@ public: //--------------------------------------------------- module management
 
 protected:
 
+  //returns false, if abort requested by observer
+  bool notify_observer(size_t _n_collapses)
+  {
+    if (observer() && _n_collapses % observer()->get_step() == 0)
+    {
+      observer()->notify(_n_collapses);
+      return !observer()->abort();
+    }
+    return true;
+  }
+
   // Reset the initialized flag, and clear the bmodules_ and cmodule_
   void set_uninitialized() {
     initialized_ = false;
@@ -234,6 +280,8 @@ private: //------------------------------------------------------- private data
   // Flag if all modules were initialized
   bool       initialized_;
 
+  // observer
+  Observer* observer_;
 
 };
 

src/OpenMesh/Tools/Decimater/DecimaterT.cc

@@ -136,13 +136,13 @@ void DecimaterT<Mesh>::heap_vertex(VertexHandle _vh) {
     mesh_.property(priority_, _vh) = -1;
   }
 }
-
-//-----------------------------------------------------------------------------
-template<class Mesh>
-size_t DecimaterT<Mesh>::decimate(size_t _n_collapses) {
-
-  if (!this->is_initialized())
-    return 0;
+
+//-----------------------------------------------------------------------------
+template<class Mesh>
+size_t DecimaterT<Mesh>::decimate(size_t _n_collapses) {
+
+  if (!this->is_initialized())
+    return 0;
 
   typename Mesh::VertexIter v_it, v_end(mesh_.vertices_end());
   typename Mesh::VertexHandle vp;
@@ -212,12 +212,16 @@ size_t DecimaterT<Mesh>::decimate(size_t _n_collapses) {
 
     // update heap (former one ring of decimated vertex)
     for (s_it = support.begin(), s_end = support.end(); s_it != s_end; ++s_it) {
-      assert(!mesh_.status(*s_it).deleted());
-      heap_vertex(*s_it);
-    }
-  }
-
-  // delete heap
+      assert(!mesh_.status(*s_it).deleted());
+      heap_vertex(*s_it);
+    }
+
+    // notify observer and stop if the observer requests it
+    if (!this->notify_observer(n_collapses))
+        return n_collapses;
+  }
+
+  // delete heap
   heap_.reset();
 
 
@@ -226,13 +230,13 @@ size_t DecimaterT<Mesh>::decimate(size_t _n_collapses) {
   return n_collapses;
 }
 
-//-----------------------------------------------------------------------------
-
-template<class Mesh>
-size_t DecimaterT<Mesh>::decimate_to_faces(size_t _nv, size_t _nf) {
-
-  if (!this->is_initialized())
-    return 0;
+//-----------------------------------------------------------------------------
+
+template<class Mesh>
+size_t DecimaterT<Mesh>::decimate_to_faces(size_t _nv, size_t _nf) {
+
+  if (!this->is_initialized())
+    return 0;
 
   if (_nv >= mesh_.n_vertices() || _nf >= mesh_.n_faces())
     return 0;
@@ -313,12 +317,16 @@ size_t DecimaterT<Mesh>::decimate_to_faces(size_t _nv, size_t _nf) {
 
     // update heap (former one ring of decimated vertex)
     for (s_it = support.begin(), s_end = support.end(); s_it != s_end; ++s_it) {
-      assert(!mesh_.status(*s_it).deleted());
-      heap_vertex(*s_it);
-    }
-  }
-
-  // delete heap
+      assert(!mesh_.status(*s_it).deleted());
+      heap_vertex(*s_it);
+    }
+
+    // notify observer and stop if the observer requests it
+    if (!this->notify_observer(n_collapses))
+        return n_collapses;
+  }
+
+  // delete heap
   heap_.reset();
 
 

src/OpenMesh/Tools/Decimater/McDecimaterT.cc

@@ -198,6 +198,10 @@ size_t McDecimaterT<Mesh>::decimate(size_t _n_collapses) {
       // post-process collapse
       this->postprocess_collapse(ci);
 
+      // notify observer and stop if the observer requests it
+      if (!this->notify_observer(n_collapses))
+          return n_collapses;
+
     } else {
       if (oldCollapses == n_collapses) {
         if (collapsesUnchanged == false) {
@@ -337,6 +341,10 @@ size_t McDecimaterT<Mesh>::decimate_to_faces(size_t _nv, size_t _nf) {
       // post-process collapse
       this->postprocess_collapse(ci);
 
+      // notify observer and stop if the observer requests it
+      if (!this->notify_observer(n_collapses))
+          return n_collapses;
+
     } else {
       if (oldCollapses == n_collapses) {
         if (collapsesUnchanged == false) {
@@ -491,6 +499,10 @@ size_t McDecimaterT<Mesh>::decimate_constraints_only(float _factor) {
       // post-process collapse
       this->postprocess_collapse(ci);
 
+      // notify observer and stop if the observer requests it
+      if (!this->notify_observer(n_collapses))
+          return n_collapses;
+
     } else {
       if (oldCollapses == n_collapses) {
         if (collapsesUnchanged == false) {

src/OpenMesh/Tools/Decimater/MixedDecimaterT.cc

@@ -92,6 +92,11 @@ size_t MixedDecimaterT<Mesh>::decimate(const size_t _n_collapses, const float _m
   size_t r_collapses = 0;
   if (_mc_factor > 0.0)
     r_collapses = McDecimaterT<Mesh>::decimate(n_collapses_mc);
+
+  // returns, if the previous steps were aborted by the observer
+  if (this->observer() && this->observer()->abort())
+      return r_collapses;
+
   if (_mc_factor < 1.0)
     r_collapses += DecimaterT<Mesh>::decimate(n_collapses_inc);
 
@@ -147,6 +152,10 @@ size_t MixedDecimaterT<Mesh>::decimate_to_faces(const size_t  _n_vertices,const
   //Update the mesh::n_vertices function, otherwise the next Decimater function will delete too much
   this->mesh().garbage_collection();
 
+  // returns, if the previous steps were aborted by the observer
+  if (this->observer() && this->observer()->abort())
+      return r_collapses;
+
   //reduce the rest of the mesh
   if (_mc_factor < 1.0) {
     r_collapses += DecimaterT<Mesh>::decimate_to_faces(_n_vertices,_n_faces);