diff --git a/common/rfb/UpdateTracker.h b/common/rfb/UpdateTracker.h
new file mode 100644
index 0000000..5b51317
--- /dev/null
+++ b/common/rfb/UpdateTracker.h
@@ -0,0 +1,103 @@
+/* Copyright (C) 2002-2005 RealVNC Ltd.  All Rights Reserved.
+ * 
+ * This 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.
+ * 
+ * This software 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 this software; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307,
+ * USA.
+ */
+
+#ifndef __RFB_UPDATETRACKER_INCLUDED__
+#define __RFB_UPDATETRACKER_INCLUDED__
+
+#include <rfb/Rect.h>
+#include <rfb/Region.h>
+#include <rfb/PixelBuffer.h>
+
+namespace rfb {
+
+  class UpdateInfo {
+  public:
+    Region changed;
+    Region copied;
+    Point copy_delta;
+    bool is_empty() const {
+      return copied.is_empty() && changed.is_empty();
+    }
+    int numRects() const {
+      return copied.numRects() + changed.numRects();
+    }
+  };
+
+  class UpdateTracker {
+  public:
+    UpdateTracker() {};
+    virtual ~UpdateTracker() {};
+
+    virtual void add_changed(const Region &region) = 0;
+    virtual void add_copied(const Region &dest, const Point &delta) = 0;
+  };
+
+  class ClippingUpdateTracker : public UpdateTracker {
+  public:
+    ClippingUpdateTracker() : ut(0) {}
+    ClippingUpdateTracker(UpdateTracker* ut_, const Rect& r=Rect()) : ut(ut_), clipRect(r) {}
+    
+    void setUpdateTracker(UpdateTracker* ut_) {ut = ut_;}
+    void setClipRect(const Rect& cr) {clipRect = cr;}
+
+    virtual void add_changed(const Region &region);
+    virtual void add_copied(const Region &dest, const Point &delta);
+  protected:
+    UpdateTracker* ut;
+    Region clipRect;
+  };
+
+  class SimpleUpdateTracker : public UpdateTracker {
+  public:
+    SimpleUpdateTracker(bool use_copyrect=true);
+    virtual ~SimpleUpdateTracker();
+
+    virtual void enable_copyrect(bool enable);
+
+    virtual void add_changed(const Region &region);
+    virtual void add_copied(const Region &dest, const Point &delta);
+    virtual void subtract(const Region& region);
+
+    // Fill the supplied UpdateInfo structure with update information
+    virtual void getUpdateInfo(UpdateInfo* info, const Region& cliprgn);
+
+    // Copy the contained updates to another tracker
+    virtual void copyTo(UpdateTracker* to) const;
+
+
+    // Get the changed/copied regions
+    const Region& get_changed() const {return changed;}
+    const Region& get_copied() const {return copied;}
+    const Point& get_delta() const {return copy_delta;}
+
+    // Move the entire update region by an offset
+    void translate(const Point& p) {changed.translate(p); copied.translate(p);}
+
+    virtual bool is_empty() const {return changed.is_empty() && copied.is_empty();}
+
+    virtual void clear() {changed.clear(); copied.clear();};
+  protected:
+    Region changed;
+    Region copied;
+    Point copy_delta;
+    bool copy_enabled;
+  };
+
+}
+
+#endif // __RFB_UPDATETRACKER_INCLUDED__