protected function generate_graphics_data(&$result_file, $system_identifier)
 {
     $this->rows[] = $system_identifier;
     $rows_index = count($this->rows) - 1;
     foreach ($this->columns as $i => $cpuinfo_item) {
         switch ($cpuinfo_item) {
             case 'OpenGL Renderer':
                 $line = phodevi_parser::read_glx_renderer();
                 break;
             case 'OpenGL Version':
                 $line = phodevi_parser::software_glxinfo_version();
                 break;
             case 'GLSL Version':
                 $line = phodevi_parser::software_glxinfo_glsl_version();
                 break;
             case 'OpenGL Extensions':
                 $line = phodevi_parser::software_glxinfo_opengl_extensions();
                 break;
         }
         $this->table_data[$i][$rows_index] = $line;
     }
 }