]> de.git.xonotic.org Git - xonotic/netradiant.git/blobdiff - radiant/undo.cpp
apply misc fixes from Markus Fischer and Rambetter
[xonotic/netradiant.git] / radiant / undo.cpp
index aa75d950e27e61f415963dbfa624c0b5bbeef581..40bbcfb4513fbfda5e2faee6f4870fa74be04c81 100644 (file)
@@ -1,6 +1,6 @@
 /*
-Copyright (C) 2001-2006, William Joseph.
-All Rights Reserved.
+Copyright (C) 1999-2007 id Software, Inc. and contributors.
+For a list of contributors, see the accompanying CONTRIBUTORS file.
 
 This file is part of GtkRadiant.
 
@@ -19,572 +19,955 @@ along with GtkRadiant; if not, write to the Free Software
 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */
 
-#include "undo.h"
 
-#include "debugging/debugging.h"
-#include "warnings.h"
-
-#include "iundo.h"
-#include "preferencesystem.h"
-#include "string/string.h"
-#include "generic/callback.h"
-#include "preferences.h"
-#include "stringio.h"
-
-#include <list>
-#include <map>
-#include <set>
-
-#include "timer.h"
-
-class DebugScopeTimer
-{
-  Timer m_timer;
-  const char* m_operation;
-public:
-  DebugScopeTimer(const char* operation)
-    : m_operation(operation)
-  {
-    m_timer.start();
-  }
-  ~DebugScopeTimer()
-  {
-    unsigned int elapsed = m_timer.elapsed_msec();
-    if(elapsed > 0)
-    {
-      globalOutputStream() << m_operation << ": " << elapsed << " msec\n";
-    }
-  }
-};
-
-
-class RadiantUndoSystem : public UndoSystem
-{
-  INTEGER_CONSTANT(MAX_UNDO_LEVELS, 1024);
-
-  class Snapshot
-  {
-    class StateApplicator
-    {
-    public:
-      Undoable* m_undoable;
-    private:
-      UndoMemento* m_data;
-    public:
-
-      StateApplicator(Undoable* undoable, UndoMemento* data)
-        : m_undoable(undoable), m_data(data)
-      {
-      }
-      void restore()
-      {
-        m_undoable->importState(m_data);
-      }
-      void release()
-      {
-        m_data->release();
-      }
-    };
-  
-    typedef std::list<StateApplicator> states_t;
-    states_t m_states;
-
-  public:
-    bool empty() const
-    {
-      return m_states.empty();
-    }
-    std::size_t size() const
-    {
-      return m_states.size();
-    }
-    void save(Undoable* undoable)
-    {
-      m_states.push_front(StateApplicator(undoable, undoable->exportState()));
-    }
-    void restore()
-    {
-      for(states_t::iterator i = m_states.begin(); i != m_states.end(); ++i)
-      {
-        (*i).restore();
-      }
-    }
-    void release()
-    {
-      for(states_t::iterator i = m_states.begin(); i != m_states.end(); ++i)
-      {
-        (*i).release();
-      }
-    }
-  };
-
-  struct Operation
-  {
-    Snapshot m_snapshot;
-    CopiedString m_command;
-
-    Operation(const char* command)
-      : m_command(command)
-    {
-    }
-    ~Operation()
-    {
-      m_snapshot.release();
-    }
-  };
-
-
-  class UndoStack
-  {
-    //! Note: using std::list instead of vector/deque, to avoid copying of undos
-    typedef std::list<Operation*> Operations;
-
-    Operations m_stack;
-    Operation* m_pending;
+/*
 
-  public:
-    UndoStack() : m_pending(0)
-    {
-    }
-    ~UndoStack()
-    {
-      clear();
-    }
-    bool empty() const
-    {
-      return m_stack.empty();
-    }
-    std::size_t size() const
-    {
-      return m_stack.size();
-    }
-    Operation* back()
-    {
-      return m_stack.back();
-    }
-    const Operation* back() const
-    {
-      return m_stack.back();
-    }
-    Operation* front()
-    {
-      return m_stack.front();
-    }
-    const Operation* front() const
-    {
-      return m_stack.front();
-    }
-    void pop_front()
-    {
-      delete m_stack.front();
-      m_stack.pop_front();
-    }
-    void pop_back()
-    {
-      delete m_stack.back();
-      m_stack.pop_back();
-    }
-    void clear()
-    {
-      if(!m_stack.empty())
-      {
-        for(Operations::iterator i = m_stack.begin(); i != m_stack.end(); ++i)
-        {
-          delete *i;
-        }
-        m_stack.clear();
-      }
-    }
-    void start(const char* command)
-    {
-      if(m_pending != 0)
-      {
-        delete m_pending;
-      }
-      m_pending = new Operation(command);
-    }
-    bool finish(const char* command)
-    {
-      if(m_pending != 0)
-      {
-        delete m_pending;
-        m_pending = 0;
-        return false;
-      }
-      else
-      {
-        ASSERT_MESSAGE(!m_stack.empty(), "undo stack empty");
-        m_stack.back()->m_command = command;
-        return true;
-      }
-    }
-    void save(Undoable* undoable)
-    {
-      if(m_pending != 0)
-      {
-        m_stack.push_back(m_pending);
-        m_pending = 0;
-      }
-      back()->m_snapshot.save(undoable);
-    }
-  };
+  QERadiant Undo/Redo
 
-  UndoStack m_undo_stack;
-  UndoStack m_redo_stack;
 
-  class UndoStackFiller : public UndoObserver
-  {
-    UndoStack* m_stack;
-  public:
+basic setup:
 
-    UndoStackFiller()
-      : m_stack(0)
-    {
-    }
-    void save(Undoable* undoable)
-    {
-      ASSERT_NOTNULL(undoable);
-
-      if(m_stack != 0)
-      {
-        m_stack->save(undoable);
-        m_stack = 0;
-      }
-    }
-    void setStack(UndoStack* stack)
-    {
-      m_stack = stack;
-    }
-  };
+<-g_undolist---------g_lastundo> <---map data---> <-g_lastredo---------g_redolist->
 
-  typedef std::map<Undoable*, UndoStackFiller> undoables_t;
-  undoables_t m_undoables;
 
-  void mark_undoables(UndoStack* stack)
-  {
-    for(undoables_t::iterator i = m_undoables.begin(); i != m_undoables.end(); ++i)
-    {
-      (*i).second.setStack(stack);
-    }
-  }
-
-  std::size_t m_undo_levels;
-
-  typedef std::set<UndoTracker*> Trackers;
-  Trackers m_trackers;
-public:
-  RadiantUndoSystem()
-    : m_undo_levels(64)
-  {
-  }
-  ~RadiantUndoSystem()
-  {
-    clear();
-  }
-  UndoObserver* observer(Undoable* undoable)
-  {
-    ASSERT_NOTNULL(undoable);
-
-    return &m_undoables[undoable];
-  }
-  void release(Undoable* undoable)
-  {
-    ASSERT_NOTNULL(undoable);
-
-    m_undoables.erase(undoable);
-  }
-  void setLevels(std::size_t levels)
-  {
-    if(levels > MAX_UNDO_LEVELS())
-    {
-      levels = MAX_UNDO_LEVELS();
-    }
+  undo/redo on the world_entity is special, only the epair changes are remembered
+  and the world entity never gets deleted.
 
-    while(m_undo_stack.size() > levels)
-    {
-      m_undo_stack.pop_front();
-    }
-    m_undo_levels = levels;
-  }
-  std::size_t getLevels() const
-  {
-    return m_undo_levels;
-  }
-  std::size_t size() const
-  {
-    return m_undo_stack.size();
-  }
-  void startUndo()
-  {
-    m_undo_stack.start("unnamedCommand");
-    mark_undoables(&m_undo_stack);
-  }
-  bool finishUndo(const char* command)
-  {
-    bool changed = m_undo_stack.finish(command);
-    mark_undoables(0);
-    return changed;
-  }
-  void startRedo()
-  {
-    m_redo_stack.start("unnamedCommand");
-    mark_undoables(&m_redo_stack);
-  }
-  bool finishRedo(const char* command)
-  {
-    bool changed = m_redo_stack.finish(command);
-    mark_undoables(0);
-    return changed;
-  }
-  void start()
-  {
-    m_redo_stack.clear();
-    if(m_undo_stack.size() == m_undo_levels)
-    {
-      m_undo_stack.pop_front();
-    }
-    startUndo();
-    trackersBegin();
-  }
-  void finish(const char* command)
-  {
-    if(finishUndo(command))
-    {
-      globalOutputStream() << command << '\n';
-    }
-  }
-  void undo()
-  {
-    if(m_undo_stack.empty())
-    {
-      globalOutputStream() << "Undo: no undo available\n";
-    }
-    else
-    {
-      Operation* operation = m_undo_stack.back();
-      globalOutputStream() << "Undo: " << operation->m_command.c_str() << "\n";
-
-      startRedo();
-      trackersUndo();
-      operation->m_snapshot.restore();
-      finishRedo(operation->m_command.c_str());
-      m_undo_stack.pop_back();
-    }
-  }
-  void redo()
-  {
-    if(m_redo_stack.empty())
-    {
-      globalOutputStream() << "Redo: no redo available\n";
-    }
-    else
-    {
-      Operation* operation = m_redo_stack.back();
-      globalOutputStream() << "Redo: " << operation->m_command.c_str() << "\n";
-
-      startUndo();
-      trackersRedo();
-      operation->m_snapshot.restore();
-      finishUndo(operation->m_command.c_str());
-      m_redo_stack.pop_back();
-    }
-  }
-  void clear()
-  {
-    mark_undoables(0);
-    m_undo_stack.clear();
-    m_redo_stack.clear();
-    trackersClear();
-  }
-  void trackerAttach(UndoTracker& tracker)
-  {
-    ASSERT_MESSAGE(m_trackers.find(&tracker) == m_trackers.end(), "undo tracker already attached");
-    m_trackers.insert(&tracker);
-  }
-  void trackerDetach(UndoTracker& tracker)
-  {
-    ASSERT_MESSAGE(m_trackers.find(&tracker) != m_trackers.end(), "undo tracker cannot be detached");
-    m_trackers.erase(&tracker);
-  }
-  void trackersClear() const
-  {
-    for(Trackers::const_iterator i = m_trackers.begin(); i != m_trackers.end(); ++i)
-    {
-      (*i)->clear();
-    }
-  }
-  void trackersBegin() const
-  {
-    for(Trackers::const_iterator i = m_trackers.begin(); i != m_trackers.end(); ++i)
-    {
-      (*i)->begin();
-    }
-  }
-  void trackersUndo() const
-  {
-    for(Trackers::const_iterator i = m_trackers.begin(); i != m_trackers.end(); ++i)
-    {
-      (*i)->undo();
-    }
-  }
-  void trackersRedo() const
-  {
-    for(Trackers::const_iterator i = m_trackers.begin(); i != m_trackers.end(); ++i)
-    {
-      (*i)->redo();
-    }
-  }
-};
+  FIXME: maybe reset the Undo system at map load
+                maybe also reset the entityId at map load
+*/
 
+#include "stdafx.h"
 
+typedef struct undo_s
+{
+       double time;                            //time operation was performed
+       int id;                                         //every undo has an unique id
+       int done;                                       //true when undo is build
+       const char *operation;                  //name of the operation
+       brush_t brushlist;                      //deleted brushes
+       entity_t entitylist;            //deleted entities
+       struct undo_s *prev, *next;     //next and prev undo in list
+} undo_t;
+
+undo_t *g_undolist;                                            //first undo in the list
+undo_t *g_lastundo;                                            //last undo in the list
+undo_t *g_redolist;                                            //first redo in the list
+undo_t *g_lastredo;                                            //last undo in list
+int g_undoMaxSize = 64;                                        //maximum number of undos
+int g_undoSize = 0;                                            //number of undos in the list
+int g_undoMaxMemorySize = 2*1024*1024; //maximum undo memory (default 2 MB)
+int g_undoMemorySize = 0;                              //memory size of undo buffer
+int g_undoId = 1;                                              //current undo ID (zero is invalid id)
+int g_redoId = 1;                                              //current redo ID (zero is invalid id)
 
-void UndoLevels_importString(RadiantUndoSystem& undo, const char* value)
+/*
+=============
+Undo_MemorySize
+=============
+*/
+int Undo_MemorySize(void)
 {
-  int levels;
-  Int_importString(levels, value);
-  undo.setLevels(levels);
+       return g_undoMemorySize;
 }
-typedef ReferenceCaller1<RadiantUndoSystem, const char*, UndoLevels_importString> UndoLevelsImportStringCaller;
-void UndoLevels_exportString(const RadiantUndoSystem& undo, const StringImportCallback& importer)
+
+/*
+=============
+Undo_ClearRedo
+=============
+*/
+void Undo_ClearRedo(void)
 {
-  Int_exportString(static_cast<int>(undo.getLevels()), importer);
+       undo_t *redo, *nextredo;
+       brush_t *pBrush, *pNextBrush;
+       entity_t *pEntity, *pNextEntity;
+
+       for (redo = g_redolist; redo; redo = nextredo)
+       {
+               nextredo = redo->next;
+               for (pBrush = redo->brushlist.next ; pBrush != NULL && pBrush != &redo->brushlist ; pBrush = pNextBrush)
+               {
+                       pNextBrush = pBrush->next;
+                       Brush_Free(pBrush);
+               }
+               for (pEntity = redo->entitylist.next; pEntity != NULL && pEntity != &redo->entitylist; pEntity = pNextEntity)
+               {
+                       pNextEntity = pEntity->next;
+                       Entity_Free(pEntity);
+               }
+               free(redo);
+       }
+       g_redolist = NULL;
+       g_lastredo = NULL;
+       g_redoId = 1;
 }
-typedef ConstReferenceCaller1<RadiantUndoSystem, const StringImportCallback&, UndoLevels_exportString> UndoLevelsExportStringCaller;
 
-#include "generic/callback.h"
+/*
+=============
+Undo_Clear
 
-void UndoLevelsImport(RadiantUndoSystem& self, int value)
+  Clears the undo buffer.
+=============
+*/
+void Undo_Clear(void)
 {
-  self.setLevels(value);
+       undo_t *undo, *nextundo;
+       brush_t *pBrush, *pNextBrush;
+       entity_t *pEntity, *pNextEntity;
+
+       Undo_ClearRedo();
+       for (undo = g_undolist; undo; undo = nextundo)
+       {
+               nextundo = undo->next;
+               for (pBrush = undo->brushlist.next ; pBrush != NULL && pBrush != &undo->brushlist ; pBrush = pNextBrush)
+               {
+                       pNextBrush = pBrush->next;
+                       g_undoMemorySize -= Brush_MemorySize(pBrush);
+                       Brush_Free(pBrush);
+               }
+               for (pEntity = undo->entitylist.next; pEntity != NULL && pEntity != &undo->entitylist; pEntity = pNextEntity)
+               {
+                       pNextEntity = pEntity->next;
+                       g_undoMemorySize -= Entity_MemorySize(pEntity);
+                       Entity_Free(pEntity);
+               }
+               g_undoMemorySize -= sizeof(undo_t);
+               free(undo);
+       }
+       g_undolist = NULL;
+       g_lastundo = NULL;
+       g_undoSize = 0;
+       g_undoMemorySize = 0;
+       g_undoId = 1;
 }
-typedef ReferenceCaller1<RadiantUndoSystem, int, UndoLevelsImport> UndoLevelsImportCaller;
-void UndoLevelsExport(const RadiantUndoSystem& self, const IntImportCallback& importCallback)
+
+/*
+=============
+Undo_SetMaxSize
+=============
+*/
+void Undo_SetMaxSize(int size)
 {
-  importCallback(static_cast<int>(self.getLevels()));
+       Undo_Clear();
+       if (size < 1) g_undoMaxSize = 1;
+       else g_undoMaxSize = size;
 }
-typedef ConstReferenceCaller1<RadiantUndoSystem, const IntImportCallback&, UndoLevelsExport> UndoLevelsExportCaller;
 
+/*
+=============
+Undo_GetMaxSize
+=============
+*/
+int Undo_GetMaxSize(void)
+{
+       return g_undoMaxSize;
+}
 
-void Undo_constructPreferences(RadiantUndoSystem& undo, PreferencesPage& page)
+/*
+=============
+Undo_SetMaxMemorySize
+=============
+*/
+void Undo_SetMaxMemorySize(int size)
 {
-  page.appendSpinner("Undo Queue Size", 64, 0, 1024, IntImportCallback(UndoLevelsImportCaller(undo)), IntExportCallback(UndoLevelsExportCaller(undo)));
+       Undo_Clear();
+       if (size < 1024) g_undoMaxMemorySize = 1024;
+       else g_undoMaxMemorySize = size;
 }
-void Undo_constructPage(RadiantUndoSystem& undo, PreferenceGroup& group)
+
+/*
+=============
+Undo_GetMaxMemorySize
+=============
+*/
+int Undo_GetMaxMemorySize(void)
 {
-  PreferencesPage page(group.createPage("Undo", "Undo Queue Settings"));
-  Undo_constructPreferences(undo, page);
+       return g_undoMaxMemorySize;
 }
-void Undo_registerPreferencesPage(RadiantUndoSystem& undo)
+
+/*
+=============
+Undo_FreeFirstUndo
+=============
+*/
+void Undo_FreeFirstUndo(void)
 {
-  PreferencesDialog_addSettingsPage(ReferenceCaller1<RadiantUndoSystem, PreferenceGroup&, Undo_constructPage>(undo));
+       undo_t *undo;
+       brush_t *pBrush, *pNextBrush;
+       entity_t *pEntity, *pNextEntity;
+
+       //remove the oldest undo from the undo buffer
+       undo = g_undolist;
+       g_undolist = g_undolist->next;
+       g_undolist->prev = NULL;
+       //
+       for (pBrush = undo->brushlist.next ; pBrush != NULL && pBrush != &undo->brushlist ; pBrush = pNextBrush)
+       {
+               pNextBrush = pBrush->next;
+               g_undoMemorySize -= Brush_MemorySize(pBrush);
+               Brush_Free(pBrush);
+       }
+       for (pEntity = undo->entitylist.next; pEntity != NULL && pEntity != &undo->entitylist; pEntity = pNextEntity)
+       {
+               pNextEntity = pEntity->next;
+               g_undoMemorySize -= Entity_MemorySize(pEntity);
+               Entity_Free(pEntity);
+       }
+       g_undoMemorySize -= sizeof(undo_t);
+       free(undo);
+       g_undoSize--;
 }
 
-class UndoSystemDependencies : public GlobalPreferenceSystemModuleRef
+/*
+=============
+Undo_GeneralStart
+=============
+*/
+void Undo_GeneralStart(const char *operation)
 {
-};
+       undo_t *undo;
+       brush_t *pBrush;
+       entity_t *pEntity;
+
+
+       if (g_lastundo)
+       {
+               if (!g_lastundo->done)
+               {
+                       Sys_Printf("Undo_Start: WARNING last undo not finished.\n");
+               }
+       }
+
+       undo = (undo_t *) malloc(sizeof(undo_t));
+       if (!undo)
+    return;
+       memset(undo, 0, sizeof(undo_t));
+       undo->brushlist.next = &undo->brushlist;
+       undo->brushlist.prev = &undo->brushlist;
+       undo->entitylist.next = &undo->entitylist;
+       undo->entitylist.prev = &undo->entitylist;
+       if (g_lastundo)
+    g_lastundo->next = undo;
+       else
+    g_undolist = undo;
+       undo->prev = g_lastundo;
+       undo->next = NULL;
+       g_lastundo = undo;
+
+       undo->time = Sys_DoubleTime();
+       //
+       if (g_undoId > g_undoMaxSize * 2) g_undoId = 1;
+       if (g_undoId <= 0) g_undoId = 1;
+       undo->id = g_undoId++;
+       undo->done = false;
+       undo->operation = operation;
+       //reset the undo IDs of all brushes using the new ID
+       for (pBrush = active_brushes.next; pBrush != NULL && pBrush != &active_brushes; pBrush = pBrush->next)
+       {
+               if (pBrush->undoId == undo->id)
+               {
+                       pBrush->undoId = 0;
+               }
+       }
+       for (pBrush = selected_brushes.next; pBrush != NULL && pBrush != &selected_brushes; pBrush = pBrush->next)
+       {
+               if (pBrush->undoId == undo->id)
+               {
+                       pBrush->undoId = 0;
+               }
+       }
+       //reset the undo IDs of all entities using thew new ID
+       for (pEntity = entities.next; pEntity != NULL && pEntity != &entities; pEntity = pEntity->next)
+       {
+               if (pEntity->undoId == undo->id)
+               {
+                       pEntity->undoId = 0;
+               }
+       }
+       g_undoMemorySize += sizeof(undo_t);
+       g_undoSize++;
+       //undo buffer is bound to a max
+       if (g_undoSize > g_undoMaxSize)
+       {
+               Undo_FreeFirstUndo();
+       }
+}
 
-class UndoSystemAPI
+/*
+=============
+Undo_BrushInUndo
+=============
+*/
+int Undo_BrushInUndo(undo_t *undo, brush_t *brush)
 {
-  RadiantUndoSystem m_undosystem;
-public:
-  typedef UndoSystem Type;
-  STRING_CONSTANT(Name, "*");
+/*     brush_t *b;
+
+       for (b = undo->brushlist.next; b != &undo->brushlist; b = b->next)
+       {
+    // Arnout: NOTE - can't do a pointer compare as the brushes get cloned into the undo brushlist, and not just referenced from it
+    // For entities we have a unique ID, for brushes we have numberID - but brush full clone increases that anyway so it's useless right now.
+               if (b == brush) return true;
+       }*/
+  // Arnout: function is pointless right now, see above explanation
+       return false;
+}
 
-  UndoSystemAPI()
-  {
-    GlobalPreferenceSystem().registerPreference("UndoLevels", makeIntStringImportCallback(UndoLevelsImportCaller(m_undosystem)), makeIntStringExportCallback(UndoLevelsExportCaller(m_undosystem)));
+/*
+=============
+Undo_EntityInUndo
+=============
+*/
+int Undo_EntityInUndo(undo_t *undo, entity_t *ent)
+{
+       entity_t *e;
+
+       for (e = undo->entitylist.next; e != &undo->entitylist; e = e->next)
+       {
+    // Arnout: NOTE - can't do a pointer compare as the entities get cloned into the undo entitylist, and not just referenced from it
+               //if (e == ent) return true;
+    if( e->entityId == ent->entityId ) return true;
+       }
+       return false;
+}
 
-    Undo_registerPreferencesPage(m_undosystem);
-  }
-  UndoSystem* getTable()
-  {
-    return &m_undosystem;
-  }
-};
+/*
+=============
+Undo_Start
+=============
+*/
+void Undo_Start(const char *operation)
+{
+       // spog - disable undo if undo levels = 0
+       if (g_PrefsDlg.m_nUndoLevels == 0)
+       {
+#ifdef DBG_UNDO
+               Sys_Printf("Undo_Start: undo is disabled.\n");
+#endif
+               return;
+       }
 
-#include "modulesystem/singletonmodule.h"
-#include "modulesystem/moduleregistry.h"
+       Undo_ClearRedo();
+       Undo_GeneralStart(operation);
+}
 
-typedef SingletonModule<UndoSystemAPI, UndoSystemDependencies> UndoSystemModule;
-typedef Static<UndoSystemModule> StaticUndoSystemModule;
-StaticRegisterModule staticRegisterUndoSystem(StaticUndoSystemModule::instance());
+/*
+=============
+Undo_AddBrush
+=============
+*/
+void Undo_AddBrush(brush_t *pBrush)
+{
+       // spog - disable undo if undo levels = 0
+       if (g_PrefsDlg.m_nUndoLevels == 0)
+       {
+#ifdef DBG_UNDO
+               Sys_Printf("Undo_AddBrush: undo is disabled.\n");
+#endif
+               return;
+       }
+
+       if (!g_lastundo)
+       {
+               Sys_Printf("Undo_AddBrushList: no last undo.\n");
+               return;
+       }
+       if (g_lastundo->entitylist.next != &g_lastundo->entitylist)
+       {
+               Sys_Printf("Undo_AddBrushList: WARNING adding brushes after entity.\n");
+       }
+       //if the brush is already in the undo
+       if (Undo_BrushInUndo(g_lastundo, pBrush))
+               return;
+       //clone the brush
+       brush_t* pClone = Brush_FullClone(pBrush);
+       //save the ID of the owner entity
+       pClone->ownerId = pBrush->owner->entityId;
+       //save the old undo ID for previous undos
+       pClone->undoId = pBrush->undoId;
+       Brush_AddToList (pClone, &g_lastundo->brushlist);
+       //
+       g_undoMemorySize += Brush_MemorySize(pClone);
+}
 
+/*
+=============
+Undo_AddBrushList
+TTimo: some brushes are just there for UI, and the information is somewhere else
+for patches it's in the patchMesh_t structure, so when we clone the brush we get that information (brush_t::pPatch)
+but: models are stored in pBrush->owner->md3Class, and owner epairs and origin parameters are important
+  so, we detect models and push the entity in the undo session (as well as it's BBox brush)
+       same for other items like weapons and ammo etc.
+=============
+*/
+void Undo_AddBrushList(brush_t *brushlist)
+{
+       // spog - disable undo if undo levels = 0
+       if (g_PrefsDlg.m_nUndoLevels == 0)
+       {
+#ifdef DBG_UNDO
+               Sys_Printf("Undo_AddBrushList: undo is disabled.\n");
+#endif
+               return;
+       }
+
+       brush_t *pBrush;
+
+       if (!g_lastundo)
+       {
+               Sys_Printf("Undo_AddBrushList: no last undo.\n");
+               return;
+       }
+       if (g_lastundo->entitylist.next != &g_lastundo->entitylist)
+       {
+               Sys_Printf("Undo_AddBrushList: WARNING adding brushes after entity.\n");
+       }
+       //copy the brushes to the undo
+       for (pBrush = brushlist->next ; pBrush != NULL && pBrush != brushlist; pBrush=pBrush->next)
+       {
+               //if the brush is already in the undo
+               //++timo FIXME: when does this happen?
+               if (Undo_BrushInUndo(g_lastundo, pBrush))
+                       continue;
+               // do we need to store this brush's entity in the undo?
+               // if it's a fixed size entity, the brush that reprents it is not really relevant, it's used for selecting and moving around
+               // what we want to store for undo is the owner entity, epairs and origin/angle stuff
+               //++timo FIXME: if the entity is not fixed size I don't know, so I don't do it yet
+               if (pBrush->owner->eclass->fixedsize == 1)
+                       Undo_AddEntity( pBrush->owner );
+               // clone the brush
+               brush_t* pClone = Brush_FullClone(pBrush);
+               // save the ID of the owner entity
+               pClone->ownerId = pBrush->owner->entityId;
+               // save the old undo ID from previous undos
+               pClone->undoId = pBrush->undoId;
+               Brush_AddToList (pClone, &g_lastundo->brushlist);
+               // track memory size used by undo
+               g_undoMemorySize += Brush_MemorySize(pClone);
+       }
+}
 
+/*
+=============
+Undo_EndBrush
+=============
+*/
+void Undo_EndBrush(brush_t *pBrush)
+{
+       // spog - disable undo if undo levels = 0
+       if (g_PrefsDlg.m_nUndoLevels == 0)
+       {
+#ifdef DBG_UNDO
+               Sys_Printf("Undo_EndBrush: undo is disabled.\n");
+#endif
+               return;
+       }
+
+
+       if (!g_lastundo)
+       {
+               //Sys_Printf("Undo_End: no last undo.\n");
+               return;
+       }
+       if (g_lastundo->done)
+       {
+               //Sys_Printf("Undo_End: last undo already finished.\n");
+               return;
+       }
+       pBrush->undoId = g_lastundo->id;
+}
 
+/*
+=============
+Undo_EndBrushList
+=============
+*/
+void Undo_EndBrushList(brush_t *brushlist)
+{
+       // spog - disable undo if undo levels = 0
+       if (g_PrefsDlg.m_nUndoLevels == 0)
+       {
+#ifdef DBG_UNDO
+               Sys_Printf("Undo_EndBrushList: undo is disabled.\n");
+#endif
+               return;
+       }
+
+
+       if (!g_lastundo)
+       {
+               //Sys_Printf("Undo_End: no last undo.\n");
+               return;
+       }
+       if (g_lastundo->done)
+       {
+               //Sys_Printf("Undo_End: last undo already finished.\n");
+               return;
+       }
+       for (brush_t* pBrush = brushlist->next; pBrush != NULL && pBrush != brushlist; pBrush=pBrush->next)
+       {
+               pBrush->undoId = g_lastundo->id;
+       }
+}
 
+/*
+=============
+Undo_AddEntity
+=============
+*/
+void Undo_AddEntity(entity_t *entity)
+{
+       // spog - disable undo if undo levels = 0
+       if (g_PrefsDlg.m_nUndoLevels == 0)
+       {
+#ifdef DBG_UNDO
+               Sys_Printf("Undo_AddEntity: undo is disabled.\n");
+#endif
+               return;
+       }
+
+
+       entity_t* pClone;
+
+       if (!g_lastundo)
+       {
+               Sys_Printf("Undo_AddEntity: no last undo.\n");
+               return;
+       }
+       //if the entity is already in the undo
+       if (Undo_EntityInUndo(g_lastundo, entity))
+               return;
+       //clone the entity
+       pClone = Entity_Clone(entity);
+       //save the old undo ID for previous undos
+       pClone->undoId = entity->undoId;
+       //save the entity ID (we need a full clone)
+       pClone->entityId = entity->entityId;
+       //
+       Entity_AddToList(pClone, &g_lastundo->entitylist);
+       //
+       g_undoMemorySize += Entity_MemorySize(pClone);
+}
 
+/*
+=============
+Undo_EndEntity
+=============
+*/
+void Undo_EndEntity(entity_t *entity)
+{
+       // spog - disable undo if undo levels = 0
+       if (g_PrefsDlg.m_nUndoLevels == 0)
+       {
+#ifdef DBG_UNDO
+               Sys_Printf("Undo_EndEntity: undo is disabled.\n");
+#endif
+               return;
+       }
 
 
+       if (!g_lastundo)
+       {
+#ifdef _DEBUG
+               Sys_Printf("Undo_End: no last undo.\n");
+#endif
+               return;
+       }
+       if (g_lastundo->done)
+       {
+#ifdef _DEBUG
+               Sys_Printf("Undo_End: last undo already finished.\n");
+#endif
+               return;
+       }
+       if (entity == world_entity)
+       {
+               //Sys_Printf("Undo_AddEntity: undo on world entity.\n");
+               //NOTE: we never delete the world entity when undoing an operation
+               //              we only transfer the epairs
+               return;
+       }
+       entity->undoId = g_lastundo->id;
+}
 
+/*
+=============
+Undo_End
+=============
+*/
+void Undo_End(void)
+{
+       // spog - disable undo if undo levels = 0
+       if (g_PrefsDlg.m_nUndoLevels == 0)
+       {
+#ifdef DBG_UNDO
+               Sys_Printf("Undo_End: undo is disabled.\n");
+#endif
+               return;
+       }
+
+
+       if (!g_lastundo)
+       {
+               //Sys_Printf("Undo_End: no last undo.\n");
+               return;
+       }
+       if (g_lastundo->done)
+       {
+               //Sys_Printf("Undo_End: last undo already finished.\n");
+               return;
+       }
+       g_lastundo->done = true;
+
+       //undo memory size is bound to a max
+       while (g_undoMemorySize > g_undoMaxMemorySize)
+       {
+               //always keep one undo
+               if (g_undolist == g_lastundo) break;
+               Undo_FreeFirstUndo();
+       }
+       //
+       //Sys_Printf("undo size = %d, undo memory = %d\n", g_undoSize, g_undoMemorySize);
+}
 
+/*
+=============
+Undo_Undo
+=============
+*/
+void Undo_Undo(boolean bSilent)
+{
+       // spog - disable undo if undo levels = 0
+       if (g_PrefsDlg.m_nUndoLevels == 0)
+       {
+               Sys_Printf("Undo_Undo: undo is disabled.\n");
+               return;
+       }
+
+       undo_t *undo, *redo;
+       brush_t *pBrush, *pNextBrush;
+       entity_t *pEntity, *pNextEntity, *pUndoEntity;
+
+       if (!g_lastundo)
+       {
+               Sys_Printf("Nothing left to undo.\n");
+               return;
+       }
+       if (!g_lastundo->done)
+       {
+               Sys_Printf("Undo_Undo: WARNING: last undo not yet finished!\n");
+       }
+       // get the last undo
+       undo = g_lastundo;
+       if (g_lastundo->prev) g_lastundo->prev->next = NULL;
+       else g_undolist = NULL;
+       g_lastundo = g_lastundo->prev;
+
+       //allocate a new redo
+       redo = (undo_t *) malloc(sizeof(undo_t));
+       if (!redo) return;
+       memset(redo, 0, sizeof(undo_t));
+       redo->brushlist.next = &redo->brushlist;
+       redo->brushlist.prev = &redo->brushlist;
+       redo->entitylist.next = &redo->entitylist;
+       redo->entitylist.prev = &redo->entitylist;
+       if (g_lastredo) g_lastredo->next = redo;
+       else g_redolist = redo;
+       redo->prev = g_lastredo;
+       redo->next = NULL;
+       g_lastredo = redo;
+       redo->time = Sys_DoubleTime();
+       redo->id = g_redoId++;
+       redo->done = true;
+       redo->operation = undo->operation;
+
+       //reset the redo IDs of all brushes using the new ID
+       for (pBrush = active_brushes.next; pBrush != NULL && pBrush != &active_brushes; pBrush = pBrush->next)
+       {
+               if (pBrush->redoId == redo->id)
+               {
+                       pBrush->redoId = 0;
+               }
+       }
+       for (pBrush = selected_brushes.next; pBrush != NULL && pBrush != &selected_brushes; pBrush = pBrush->next)
+       {
+               if (pBrush->redoId == redo->id)
+               {
+                       pBrush->redoId = 0;
+               }
+       }
+       //reset the redo IDs of all entities using thew new ID
+       for (pEntity = entities.next; pEntity != NULL && pEntity != &entities; pEntity = pEntity->next)
+       {
+               if (pEntity->redoId == redo->id)
+               {
+                       pEntity->redoId = 0;
+               }
+       }
+
+       // deselect current sutff
+       Select_Deselect();
+       // move "created" brushes to the redo
+       for (pBrush = active_brushes.next; pBrush != NULL && pBrush != &active_brushes; pBrush=pNextBrush)
+       {
+               pNextBrush = pBrush->next;
+               if (pBrush->undoId == undo->id)
+               {
+                       //Brush_Free(pBrush);
+                       //move the brush to the redo
+                       Brush_RemoveFromList(pBrush);
+                       Brush_AddToList(pBrush, &redo->brushlist);
+                       //make sure the ID of the owner is stored
+                       pBrush->ownerId = pBrush->owner->entityId;
+                       //unlink the brush from the owner entity
+                       Entity_UnlinkBrush(pBrush);
+               }
+       }
+       // move "created" entities to the redo
+       for (pEntity = entities.next; pEntity != NULL && pEntity != &entities; pEntity = pNextEntity)
+       {
+               pNextEntity = pEntity->next;
+               if (pEntity->undoId == undo->id)
+               {
+                       // check if this entity is in the undo
+                       for (pUndoEntity = undo->entitylist.next; pUndoEntity != NULL && pUndoEntity != &undo->entitylist; pUndoEntity = pUndoEntity->next)
+                       {
+                               // move brushes to the undo entity
+                               if (pUndoEntity->entityId == pEntity->entityId)
+                               {
+                                       pUndoEntity->brushes.next = pEntity->brushes.next;
+                                       pUndoEntity->brushes.prev = pEntity->brushes.prev;
+                                       pEntity->brushes.next = &pEntity->brushes;
+                                       pEntity->brushes.prev = &pEntity->brushes;
+                               }
+                       }
+                       //
+                       //Entity_Free(pEntity);
+                       //move the entity to the redo
+                       Entity_RemoveFromList(pEntity);
+                       Entity_AddToList(pEntity, &redo->entitylist);
+               }
+       }
+       // add the undo entities back into the entity list
+       for (pEntity = undo->entitylist.next; pEntity != NULL && pEntity != &undo->entitylist; pEntity = undo->entitylist.next)
+       {
+               g_undoMemorySize -= Entity_MemorySize(pEntity);
+               //if this is the world entity
+               if (pEntity->entityId == world_entity->entityId)
+               {
+                       epair_t* tmp = world_entity->epairs;
+                       world_entity->epairs = pEntity->epairs;
+      pEntity->epairs = tmp;
+                       Entity_Free(pEntity);
+               }
+               else
+               {
+                       Entity_RemoveFromList(pEntity);
+                       Entity_AddToList(pEntity, &entities);
+                       pEntity->redoId = redo->id;
+               }
+       }
+       // add the undo brushes back into the selected brushes
+       for (pBrush = undo->brushlist.next; pBrush != NULL && pBrush != &undo->brushlist; pBrush = undo->brushlist.next)
+       {
+               //Sys_Printf("Owner ID: %i\n",pBrush->ownerId);
+               g_undoMemorySize -= Brush_MemorySize(pBrush);
+               Brush_RemoveFromList(pBrush);
+       Brush_AddToList(pBrush, &active_brushes);
+               for (pEntity = entities.next; pEntity != NULL && pEntity != &entities; pEntity = pEntity->next) // fixes broken undo on entities
+               {
+                       //Sys_Printf("Entity ID: %i\n",pEntity->entityId);
+                       if (pEntity->entityId == pBrush->ownerId)
+                       {
+                               Entity_LinkBrush(pEntity, pBrush);
+                               break;
+                       }
+               }
+               //if the brush is not linked then it should be linked into the world entity
+               //++timo FIXME: maybe not, maybe we've lost this entity's owner!
+               if (pEntity == NULL || pEntity == &entities)
+               {
+                       Entity_LinkBrush(world_entity, pBrush);
+               }
+               //build the brush
+               //Brush_Build(pBrush);
+               Select_Brush(pBrush);
+               pBrush->redoId = redo->id;
+    }
+       if (!bSilent)
+               Sys_Printf("%s undone.\n", undo->operation);
+       // free the undo
+       g_undoMemorySize -= sizeof(undo_t);
+       free(undo);
+       g_undoSize--;
+       g_undoId--;
+       if (g_undoId <= 0) g_undoId = 2 * g_undoMaxSize;
+       //
+    g_bScreenUpdates = true;
+    UpdateSurfaceDialog();
+    Sys_UpdateWindows(W_ALL);
+}
 
-class undoable_test : public Undoable
+/*
+=============
+Undo_Redo
+=============
+*/
+void Undo_Redo(void)
 {
-  struct state_type : public UndoMemento
-  {
-    state_type() : test_data(0)
-    {
-    }
-    state_type(const state_type& other) : UndoMemento(other), test_data(other.test_data)
-    {
-    }
-    void release()
-    {
-      delete this;
-    }
+       // spog - disable undo if undo levels = 0
+       if (g_PrefsDlg.m_nUndoLevels == 0)
+       {
+               Sys_Printf("Undo_Redo: undo is disabled.\n");
+               return;
+       }
+
+       undo_t *redo;
+       brush_t *pBrush, *pNextBrush;
+       entity_t *pEntity, *pNextEntity, *pRedoEntity;
+
+       if (!g_lastredo)
+       {
+               Sys_Printf("Nothing left to redo.\n");
+               return;
+       }
+       if (g_lastundo)
+       {
+               if (!g_lastundo->done)
+               {
+                       Sys_Printf("WARNING: last undo not finished.\n");
+               }
+       }
+       // get the last redo
+       redo = g_lastredo;
+       if (g_lastredo->prev) g_lastredo->prev->next = NULL;
+       else g_redolist = NULL;
+       g_lastredo = g_lastredo->prev;
+       //
+       Undo_GeneralStart(redo->operation);
+       // remove current selection
+       Select_Deselect();
+       // move "created" brushes back to the last undo
+       for (pBrush = active_brushes.next; pBrush != NULL && pBrush != &active_brushes; pBrush = pNextBrush)
+       {
+               pNextBrush = pBrush->next;
+               if (pBrush->redoId == redo->id)
+               {
+                       //move the brush to the undo
+                       Brush_RemoveFromList(pBrush);
+                       Brush_AddToList(pBrush, &g_lastundo->brushlist);
+                       g_undoMemorySize += Brush_MemorySize(pBrush);
+                       pBrush->ownerId = pBrush->owner->entityId;
+                       Entity_UnlinkBrush(pBrush);
+               }
+       }
+       // move "created" entities back to the last undo
+       for (pEntity = entities.next; pEntity != NULL && pEntity != &entities; pEntity = pNextEntity)
+       {
+               pNextEntity = pEntity->next;
+               if (pEntity->redoId == redo->id)
+               {
+                       // check if this entity is in the redo
+                       for (pRedoEntity = redo->entitylist.next; pRedoEntity != NULL && pRedoEntity != &redo->entitylist; pRedoEntity = pRedoEntity->next)
+                       {
+                               // move brushes to the redo entity
+                               if (pRedoEntity->entityId == pEntity->entityId)
+                               {
+                                       pRedoEntity->brushes.next = pEntity->brushes.next;
+                                       pRedoEntity->brushes.prev = pEntity->brushes.prev;
+                                       pEntity->brushes.next = &pEntity->brushes;
+                                       pEntity->brushes.prev = &pEntity->brushes;
+                               }
+                       }
+                       //
+                       //Entity_Free(pEntity);
+                       //move the entity to the redo
+                       Entity_RemoveFromList(pEntity);
+                       Entity_AddToList(pEntity, &g_lastundo->entitylist);
+                       g_undoMemorySize += Entity_MemorySize(pEntity);
+               }
+       }
+       // add the undo entities back into the entity list
+       for (pEntity = redo->entitylist.next; pEntity != NULL && pEntity != &redo->entitylist; pEntity = redo->entitylist.next)
+       {
+               //if this is the world entity
+               if (pEntity->entityId == world_entity->entityId)
+               {
+      epair_t* tmp = world_entity->epairs;
+                       world_entity->epairs = pEntity->epairs;
+      pEntity->epairs = tmp;
+                       Entity_Free(pEntity);
+               }
+               else
+               {
+                       Entity_RemoveFromList(pEntity);
+                       Entity_AddToList(pEntity, &entities);
+               }
+       }
+       // add the redo brushes back into the selected brushes
+       for (pBrush = redo->brushlist.next; pBrush != NULL && pBrush != &redo->brushlist; pBrush = redo->brushlist.next)
+       {
+               Brush_RemoveFromList(pBrush);
+    Brush_AddToList(pBrush, &active_brushes);
+               for (pEntity = entities.next; pEntity != NULL && pEntity != &entities; pEntity = pEntity->next) // fixes broken undo on entities
+               {
+                       if (pEntity->entityId == pBrush->ownerId)
+                       {
+                               Entity_LinkBrush(pEntity, pBrush);
+                               break;
+                       }
+               }
+               //if the brush is not linked then it should be linked into the world entity
+               if (pEntity == NULL || pEntity == &entities)
+               {
+                       Entity_LinkBrush(world_entity, pBrush);
+               }
+               //build the brush
+               //Brush_Build(pBrush);
+               Select_Brush(pBrush);
+    }
+       //
+       Undo_End();
+       //
+       Sys_Printf("%s redone.\n", redo->operation);
+       //
+       g_redoId--;
+       // free the undo
+       free(redo);
+       //
+    g_bScreenUpdates = true;
+    UpdateSurfaceDialog();
+    Sys_UpdateWindows(W_ALL);
+}
 
-    int test_data;
-  };
-  state_type m_state;
-  UndoObserver* m_observer;
-public:
-  undoable_test()
-    : m_observer(GlobalUndoSystem().observer(this))
-  {
-  }
-  ~undoable_test()
-  {
-    GlobalUndoSystem().release(this);
-  }
-  UndoMemento* exportState() const
-  {
-    return new state_type(m_state);
-  }
-  void importState(const UndoMemento* state)
-  {
-    ASSERT_NOTNULL(state);
-
-    m_observer->save(this);
-    m_state = *(static_cast<const state_type*>(state));
-  }
-
-  void mutate(unsigned int data)
-  {
-    m_observer->save(this);
-    m_state.test_data = data;
-  }
-};
-
-#if 0
-
-class TestUndo
+/*
+=============
+Undo_RedoAvailable
+=============
+*/
+int Undo_RedoAvailable(void)
 {
-public:
-  TestUndo()
-  {
-    undoable_test test;
-    GlobalUndoSystem().begin("bleh");
-    test.mutate(3);
-    GlobalUndoSystem().begin("blah");
-    test.mutate(4);
-    GlobalUndoSystem().undo();
-    GlobalUndoSystem().undo();
-    GlobalUndoSystem().redo();
-    GlobalUndoSystem().redo();
-  }
-};
-
-TestUndo g_TestUndo;
+       if (g_lastredo) return true;
+       return false;
+}
 
-#endif
+int Undo_GetUndoId(void)
+{
+       if (g_lastundo)
+               return g_lastundo->id;
+       return 0;
+}
 
+/*
+=============
+Undo_UndoAvailable
+=============
+*/
+int Undo_UndoAvailable(void)
+{
+       if (g_lastundo)
+       {
+               if (g_lastundo->done)
+                       return true;
+       }
+       return false;
+}