new file mode 100644
--- /dev/null
+++ b/src/graphics/opengl/gl-render.h
@@ -0,0 +1,118 @@
+/*
+
+Copyright (C) 2008 Michael Goffioul
+
+This file is part of Octave.
+
+Octave 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 3 of the License, or (at your
+option) any later version.
+
+Octave 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 Octave; see the file COPYING.  If not, see
+<http://www.gnu.org/licenses/>.
+
+*/
+
+#if !defined (gl_render_h)
+#define gl_render_h 1
+
+#include "graphics.h"
+
+class
+OCTGRAPHICS_API
+opengl_renderer
+{
+public:
+  opengl_renderer (void) { }
+
+  virtual ~opengl_renderer (void) { }
+
+  virtual void draw (const graphics_handle& h)
+    { draw (gh_manager::get_object (h)); }
+
+  virtual void draw (const graphics_object& go);
+
+  virtual void draw (const Matrix& hlist)
+    {
+      int len = hlist.length ();
+
+      for (int i = 0; i < len; i++)
+	{
+	  graphics_handle h = gh_manager::lookup (hlist(i));
+
+	  if (h.ok ())
+	    draw (h);
+	}
+    }
+
+  virtual void set_viewport (int w, int h);
+
+protected:
+  virtual void draw (const figure::properties& props);
+  virtual void draw (const axes::properties& props);
+  virtual void draw (const line::properties& props);
+
+  virtual void set_color (const Matrix& c);
+  virtual void set_polygon_offset (bool on, double offset = 0.0);
+  virtual void set_linewidth (float w);
+  virtual void set_linestyle (const std::string& s, bool stipple = false);
+  virtual void set_clipbox (double x1, double x2, double y1, double y2,
+			    double z1, double z2);
+  virtual void set_clipping (bool on);
+
+  virtual void init_marker (const std::string& m, double size, float width);
+  virtual void end_marker (void);
+  virtual void draw_marker (double x, double y, double z,
+			    const Matrix& lc, const Matrix& fc);
+
+private:
+  opengl_renderer (const opengl_renderer&) { }
+
+  opengl_renderer& operator = (const opengl_renderer&)
+    { return *this; }
+
+  bool is_nan_or_inf (double x, double y, double z) const
+    {
+      return (xisnan (x) || xisnan (y) || xisnan (z)
+	      || xisinf (x) || xisinf (y) || xisinf (z));
+    }
+
+  octave_uint8 clip_code (double x, double y, double z) const
+    {
+      return ((x < xmin ? 1 : 0)
+	      | (x > xmax ? 1 : 0) << 1
+	      | (y < ymin ? 1 : 0) << 2
+	      | (y > ymax ? 1 : 0) << 3
+	      | (z < zmin ? 1 : 0) << 4
+	      | (z > zmax ? 1 : 0) << 5
+	      | (is_nan_or_inf (x, y, z) ? 0 : 1) << 6);
+    }
+
+  unsigned int make_marker_list (const std::string& m, double size,
+				 bool filled) const;
+
+private:
+  /* the backend associated with the figure being rendered */
+  graphics_backend backend;
+  /* axes transformation data */
+  graphics_xform xform;
+  /* axis limits in model scaled coordinate */
+  double xmin, xmax;
+  double ymin, ymax;
+  double zmin, zmax;
+  /* Z projection limits in windows coordinate */
+  double xZ1, xZ2;
+  /* call lists identifiers for markers */
+  unsigned int marker_id, filled_marker_id;
+  /* camera information for primitive sorting */
+  ColumnVector camera_pos, camera_dir;
+};
+
+#endif