createProgram( m_vertex_program, filename.c_str(), GL_VERTEX_PROGRAM_NV );
glGenProgramsNV( 1, &m_fragment_program );
glBindProgramNV( GL_FRAGMENT_PROGRAM_NV, m_fragment_program );
filename.clear();
createProgram( m_vertex_program, filename.c_str(), GL_VERTEX_PROGRAM_NV );
glGenProgramsNV( 1, &m_fragment_program );
glBindProgramNV( GL_FRAGMENT_PROGRAM_NV, m_fragment_program );
filename.clear();