/***********************************************************************
    created:    Sat Jan 31 2009
    author:     Paul D Turner
*************************************************************************/
/***************************************************************************
     Copyright (C) 2004 - 2011 Paul D Turner & The CEGUI Development Team

     Permission is hereby granted, free of charge, to any person obtaining
     a copy of this software and associated documentation files (the
     "Software"), to deal in the Software without restriction, including
     without limitation the rights to use, copy, modify, merge, publish,
     distribute, sublicense, and/or sell copies of the Software, and to
     permit persons to whom the Software is furnished to do so, subject to
     the following conditions:

     The above copyright notice and this permission notice shall be
     included in all copies or substantial portions of the Software.

     THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
     EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
     MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
     IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR
     OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
     ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
     OTHER DEALINGS IN THE SOFTWARE.
 ***************************************************************************/
#ifndef _CEGUIOpenGLGLXPBTextureTarget_h_
#define _CEGUIOpenGLGLXPBTextureTarget_h_

#include <GL/glxew.h>

#include "CEGUI/RendererModules/OpenGL/TextureTarget.h"

// Start of CEGUI namespace section
namespace CEGUI
{
  class OpenGLTexture;

  /*!
    \brief
      OpenGLGLXPBTextureTarget - allows rendering to an OpenGL texture via the
      pbuffer provided in GLX 1.3 and above.
  */
  class OPENGL_GUIRENDERER_API OpenGLGLXPBTextureTarget : public OpenGLTextureTarget
  {
  public:
    OpenGLGLXPBTextureTarget(OpenGLRendererBase &owner);
    virtual ~OpenGLGLXPBTextureTarget();

    // overrides from OpenGLRenderTarget
    void activate();
    void deactivate();
    // implementation of TextureTarget interface
    void clear();
    void declareRenderSize(const Sizef &sz);
    // specialise functions from OpenGLTextureTarget
    void grabTexture();
    void restoreTexture();

  protected:
    //! default size of created texture objects
    static const float DEFAULT_SIZE;

    //! Initialise the PBuffer with the needed size
    void initialisePBuffer();

    //! Switch rendering so it targets the pbuffer
    void enablePBuffer() const;

    //! Switch rendering to target what was active before the pbuffer was used.
    void disablePBuffer() const;

    //! Perform basic initialisation of the texture we're going to use.
    void initialiseTexture();

    //! Selects an appropriate FB config to use and stores in d_fbconfig.
    void selectFBConfig();

    //!Creates the context to use with the pbuffer.
    void createContext();

    //! X server display.
    Display *d_dpy;
    //! GLX config used in creating pbuffer
    GLXFBConfig d_fbconfig;
    //! GLX context
    GLXContext d_context;
    //! The GLX pbuffer we're using.
    GLXPbuffer d_pbuffer;
    //! stores previous X display when switching to pbuffer
    mutable Display *d_prevDisplay;
    //! stores previous GLX drawable when switching to pbuffer
    mutable GLXDrawable d_prevDrawable;
    //! stores previous GLX context when switching to pbuffer
    mutable GLXContext d_prevContext;
  };

} // End of  CEGUI namespace section

#endif  // end of guard _CEGUIOpenGLGLXPBTextureTarget_h_
