virtual void ReadBuffer( GLenum mode ) = 0;
virtual void DrawRangeElements( GLenum mode, GLuint start, GLuint end, GLsizei count, GLenum type, const GLvoid* indices ) = 0;
virtual void ReadBuffer( GLenum mode ) = 0;
virtual void DrawRangeElements( GLenum mode, GLuint start, GLuint end, GLsizei count, GLenum type, const GLvoid* indices ) = 0;