case $THIS_SUB_DEPENDS in
  NV|NOUVEAU) [[ "$LIBDRM_NV" == "y" ]] && return 0 ;;
  INTEL) [[ "$LIBDRM_INTEL" == "y" ]] && return 0 ;;
 RADEON) [[ "$LIBDRM_RADEON" == "y" ]] && return 0 ;;
      *) message "${PROBLEM_COLOR}bogus sub_depends: $SPELL $THIS_SUB_DEPENDS${DEFAULT_COLOR}"
         return 1;;
esac

.