/***********************************************************************
  created:    Wed, 8th Feb 2012
  author:     Lukas E Meindl
*************************************************************************/
/***************************************************************************
    Copyright (C) 2004 - 2012 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 _CEGUIOpenGL3Shader_h_
#define _CEGUIOpenGL3Shader_h_

#include "CEGUI/Exceptions.h"
#include "RendererBase.h"
#include <string>

#if defined(_MSC_VER)
#   pragma warning(push)
#   pragma warning(disable : 4251)
#endif

// Start of CEGUI namespace section
namespace CEGUI
{

  class OPENGL_GUIRENDERER_API OpenGL3Shader :
    public AllocatedObject<OpenGL3Shader>
  {
  public:

    /*!
      \brief
        Creates and loads shader programs from the two strings supplied to it
    */
    OpenGL3Shader(const std::string &vertex_shader_source,
      const std::string &fragment_shader_source);

    ~OpenGL3Shader();

    /*!
      \brief
        Bind the shader to the OGL state-machine
    */
    void bind() const;

    /*!
      \brief
        Unbind the shader
    */
    void unbind() const;

    /*!
      \brief
        Query the location of a vertex attribute inside the shader.
    */
    gl::GLuint getAttribLocation(const std::string &name) const;

    /*!
      \brief
        Query the location of a uniform variable inside the shader.
    */
    gl::GLuint getUniformLocation(const std::string &name) const;

    /*!
      \brief
        Defines the name of the variable inside the shader which represents the
        final color for each fragment.
    */
    void bindFragDataLocation(const std::string &name);

    bool isCreatedSuccessfully();

    void link();

  private:
    gl::GLuint compile(gl::GLenum type, const std::string &source);

    void outputShaderLog(gl::GLuint shader);
    void outputProgramLog(gl::GLuint program);

    std::string d_shaderName;
    bool d_createdSucessfully;

    gl::GLuint d_vertexShader;
    gl::GLuint d_fragmentShader;
    gl::GLuint d_geometryShader;
    gl::GLuint d_program;
  };

#define STRINGIFY(x) #x
#define TOSTRING(x) STRINGIFY(x)
#define AT __FILE__ ":" TOSTRING(__LINE__)
#define checkGLErrors() getGLErrors(AT)

  /*!
    \brief
      Query OpenGL errors and process them in CEGUI
  */
  void getGLErrors(const char *location);

}

#endif

