+ [with_modlib=$withval],
+ [with_modlib=auto])
+
+use_modlib=none
+AS_CASE([$with_modlib],
+ [no|none], [:],
+ [modplug], [DX_LIB_LIBMODPLUG([use_modlib=modplug])],
+ [auto], [DX_LIB_LIBMODPLUG([use_modlib=modplug], [:])],
+ [AC_MSG_ERROR([Invalid argument to --with-modlib: $with_modlib])])