This is a library to manipulate SSFN files as well as import other formats. For the latter it has some dependencies. This library is only used by the converter and the editor, and NOT needed by the renderer. The library relies on the renderer, and not the other way around. See libsfn's API for more details.
Heavily stripped down versions of the required libraries are linked statically by default. These include:
To generate the static library, run
$ make libsfn.a
If you rather have dynamically linked dependencies (libimagequant and freetype2), then
$ USE_DYNDEPS=1 make libsfn.a
I would recommend static dependencies under Windows, and dynamic under Linux (and other POSIX systems with decent package management for shared libraries).
To exclude importing foreign font formats altogether and just support SSFN and ASC (no need for libimagequant nor freetype2), then use
$ USE_NOFOREIGN=1 make libsfn.a
Note: to avoid .dll.a linking issues under MinGW, both sfnconv and sfnedit directly links with the .o object files of libsfn. K.I.S.S.! :-)