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#ifndef ProjViewTransfCallback_INCLUDE_ONCE
#define ProjViewTransfCallback_INCLUDE_ONCE

#include <vlGraphics/link_config.hpp>
#include <vlCore/Object.hpp>

namespace vl
{
  class Renderer;
  class GLSLProgram;
  class Transform;
  class Camera;

  //-----------------------------------------------------------------------------
  // ProjViewTransfCallback
  //-----------------------------------------------------------------------------
  /** Callback class to update the state of the \p projection, \p view, \p transform and \p normal matrices of a GLSLProgram or fixed function pipeline. 
  * By default it updates the GL_PROJECTION and GL_MODELVIEW matrices. If GLSL is used and any of \p vl_ModelViewMatrix, \p vl_ProjectionMatrix, 
  * \p vl_ModelViewProjectionMatrix or \p vl_NormalMatrix is used, then no legacy uniform matrix is updated (GL_MODELVIEW, gl_ModelViewMatrix etc.)
  * but only the vl_* ones.
  * Reimplement the updateMatrices() method to update any other camera/transform matrix you might need such as the ones defined in
  * http://www.opengl.org/registry/doc/GLSLangSpec.Full.1.10.59.pdf pag 45.
  */
  class VLGRAPHICS_EXPORT ProjViewTransfCallback: public Object
  {
    VL_INSTRUMENT_CLASS(vl::ProjViewTransfCallback, Object)

  public:
    ProjViewTransfCallback()
    {
      VL_DEBUG_SET_OBJECT_NAME()
    }

    //! Update matrices of the current GLSLProgram, if glsl_program == NULL then fixed function pipeline is active.
    virtual void updateMatrices(bool cam_changed, bool transf_changed, const GLSLProgram* glsl_program, const Camera* camera, const Transform* transform);
  };
}

#endif