1 files changed, 884 insertions, 0 deletions
diff --git a/q3radiant/Undo.cpp b/q3radiant/Undo.cpp
new file mode 100755
index 0000000..ca0a74e
--- /dev/null
+++ b/q3radiant/Undo.cpp
@@ -0,0 +1,884 @@
+/*
+===========================================================================
+Copyright (C) 1999-2005 Id Software, Inc.
+
+This file is part of Quake III Arena source code.
+
+Quake III Arena source code is free software; you can redistribute it
+and/or modify it under the terms of the GNU General Public License as
+published by the Free Software Foundation; either version 2 of the License,
+or (at your option) any later version.
+
+Quake III Arena source code is distributed in the hope that it will be
+useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with Foobar; if not, write to the Free Software
+Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+===========================================================================
+*/
+
+/*
+
+  QERadiant Undo/Redo
+
+
+basic setup:
+
+<-g_undolist---------g_lastundo> <---map data---> <-g_lastredo---------g_redolist->
+
+
+  undo/redo on the world_entity is special, only the epair changes are remembered
+  and the world entity never gets deleted.
+
+  FIXME: maybe reset the Undo system at map load
+		 maybe also reset the entityId at map load
+*/
+
+#include "stdafx.h"
+#include "Radiant.h"
+#include "qe3.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
+	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)
+
+
+/*
+=============
+Undo_MemorySize
+=============
+*/
+int Undo_MemorySize(void)
+{
+	/*
+	int size;
+	undo_t *undo;
+	brush_t *pBrush;
+	entity_t *pEntity;
+
+	size = 0;
+	for (undo = g_undolist; undo; undo = undo->next)
+	{
+		for (pBrush = undo->brushlist.next ; pBrush != NULL && pBrush != &undo->brushlist ; pBrush = pBrush->next)
+		{
+			size += Brush_MemorySize(pBrush);
+		}
+		for (pEntity = undo->entitylist.next; pEntity != NULL && pEntity != &undo->entitylist; pEntity = pEntity->next)
+		{
+			size += Entity_MemorySize(pEntity);
+		}
+		size += sizeof(undo_t);
+	}
+	return size;
+	*/
+	return g_undoMemorySize;
+}
+
+/*
+=============
+Undo_ClearRedo
+=============
+*/
+void Undo_ClearRedo(void)
+{
+	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;
+}
+
+/*
+=============
+Undo_Clear
+
+  Clears the undo buffer.
+=============
+*/
+void Undo_Clear(void)
+{
+	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;
+}
+
+/*
+=============
+Undo_SetMaxSize
+=============
+*/
+void Undo_SetMaxSize(int size)
+{
+	Undo_Clear();
+	if (size < 1) g_undoMaxSize = 1;
+	else g_undoMaxSize = size;
+}
+
+/*
+=============
+Undo_GetMaxSize
+=============
+*/
+int Undo_GetMaxSize(void)
+{
+	return g_undoMaxSize;
+}
+
+/*
+=============
+Undo_SetMaxMemorySize
+=============
+*/
+void Undo_SetMaxMemorySize(int size)
+{
+	Undo_Clear();
+	if (size < 1024) g_undoMaxMemorySize = 1024;
+	else g_undoMaxMemorySize = size;
+}
+
+/*
+=============
+Undo_GetMaxMemorySize
+=============
+*/
+int Undo_GetMaxMemorySize(void)
+{
+	return g_undoMaxMemorySize;
+}
+
+/*
+=============
+Undo_FreeFirstUndo
+=============
+*/
+void Undo_FreeFirstUndo(void)
+{
+	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--;
+}
+
+/*
+=============
+Undo_GeneralStart
+=============
+*/
+void Undo_GeneralStart(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();
+	}
+}
+
+/*
+=============
+Undo_BrushInUndo
+=============
+*/
+int Undo_BrushInUndo(undo_t *undo, brush_t *brush)
+{
+	brush_t *b;
+
+	for (b = undo->brushlist.next; b != &undo->brushlist; b = b->next)
+	{
+		if (b == brush) return true;
+	}
+	return false;
+}
+
+/*
+=============
+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)
+	{
+		if (e == ent) return true;
+	}
+	return false;
+}
+
+/*
+=============
+Undo_Start
+=============
+*/
+void Undo_Start(char *operation)
+{
+	Undo_ClearRedo();
+	Undo_GeneralStart(operation);
+}
+
+/*
+=============
+Undo_AddBrush
+=============
+*/
+void Undo_AddBrush(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");
+	}
+	//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
+=============
+*/
+void Undo_AddBrushList(brush_t *brushlist)
+{
+	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
+		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);
+		//
+		g_undoMemorySize += Brush_MemorySize(pClone);
+	}
+}
+
+/*
+=============
+Undo_EndBrush
+=============
+*/
+void Undo_EndBrush(brush_t *pBrush)
+{
+	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)
+{
+	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)
+{
+	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);
+	//NOTE: Entity_Clone adds the entity to the entity list
+	//		so we remove it from that list here
+	Entity_RemoveFromList(pClone);
+	//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)
+{
+	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;
+	}
+	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)
+{
+	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(void)
+{
+	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;
+		}
+	}
+
+	// remove current selection
+	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)
+		{
+			//free the epairs of the world entity
+			Entity_FreeEpairs(world_entity);
+			//set back the original epairs
+			world_entity->epairs = pEntity->epairs;
+			// unhook the epairs and free the world_entity clone that stored the epairs
+			pEntity->epairs = NULL;
+			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)
+	{
+		g_undoMemorySize -= Brush_MemorySize(pBrush);
+		Brush_RemoveFromList(pBrush);
+    	Brush_AddToList(pBrush, &active_brushes);
+		for (pEntity = entities.next; pEntity != NULL && pEntity != &entities; pEntity = pNextEntity)
+		{
+			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);
+		pBrush->redoId = redo->id;
+    }
+	//
+	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; 
+    Sys_UpdateWindows(W_ALL);
+}
+
+/*
+=============
+Undo_Redo
+=============
+*/
+void Undo_Redo(void)
+{
+	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)
+		{
+			//free the epairs of the world entity
+			Entity_FreeEpairs(world_entity);
+			//set back the original epairs
+			world_entity->epairs = pEntity->epairs;
+			//free the world_entity clone that stored the epairs
+			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 = pNextEntity)
+		{
+			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; 
+    Sys_UpdateWindows(W_ALL);
+}
+
+/*
+=============
+Undo_RedoAvailable
+=============
+*/
+int Undo_RedoAvailable(void)
+{
+	if (g_lastredo) return true;
+	return false;
+}
+
+/*
+=============
+Undo_UndoAvailable
+=============
+*/
+int Undo_UndoAvailable(void)
+{
+	if (g_lastundo)
+	{
+		if (g_lastundo->done)
+			return true;
+	}
+	return false;
+}