diff --git a/unix/x0vncserver/Geometry.cxx b/unix/x0vncserver/Geometry.cxx
new file mode 100644
index 0000000..ccb4e69
--- /dev/null
+++ b/unix/x0vncserver/Geometry.cxx
@@ -0,0 +1,71 @@
+/* Copyright (C) 2006 Constantin Kaplinsky.  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.
+ */
+
+//
+// Geometry.cxx
+//
+
+#include <rfb/Rect.h>
+#include <rfb/LogWriter.h>
+#include <x0vncserver/Geometry.h>
+
+static LogWriter vlog("Geometry");
+
+StringParameter Geometry::m_geometryParam("Geometry",
+  "Screen area shown to VNC clients. "
+  "Format is <width>x<height>+<offset_x>+<offset_y>, "
+  "more information in man X, section GEOMETRY SPECIFICATIONS. "
+  "If the argument is empty, full screen is shown to VNC clients.",
+  "");
+
+Geometry::Geometry(int fullWidth, int fullHeight)
+  : m_width(fullWidth), m_height(fullHeight),
+    m_offsetLeft(0), m_offsetTop(0)
+{
+  const char *param = m_geometryParam.getData();
+  if (strlen(param) != 0) {
+    int w, h;
+    int x = 0, y = 0;
+    char sign_x[2] = "+";
+    char sign_y[2] = "+";
+    int n = sscanf(param, "%dx%d%1[+-]%d%1[+-]%d",
+                   &w, &h, sign_x, &x, sign_y, &y);
+    if ((n == 2 || n == 6) && w > 0 && h > 0 && x >= 0 && y >= 0) {
+      if (sign_x[0] == '-')
+        x = fullWidth - w - x;
+      if (sign_y[0] == '-')
+        y = fullHeight - h - y;
+      Rect fullRect(0, 0, fullWidth, fullHeight);
+      Rect partRect(x, y, x + w, y + h);
+      Rect r = partRect.intersect(fullRect);
+      if (r.area() > 0) {
+        m_width = r.width();
+        m_height = r.height();
+        m_offsetLeft = r.tl.x;
+        m_offsetTop = r.tl.y;
+      } else {
+        vlog.error("Requested area is out of the desktop boundaries");
+      }
+    } else {
+      vlog.error("Wrong argument format");
+    }
+  }
+  vlog.info("Desktop geometry is %dx%d+%d+%d",
+            m_width, m_height, m_offsetLeft, m_offsetTop);
+}
+