That's not a trivial task although I would like to see a Free Pascal binding for SFML. For a first start I would recommend the document "How to use C code in Free Pascal projects" which can be found here: ftp://ftp.freepascal.org/fpc/docs-pdf/CinFreePascal.pdf
This could be interesting, too: http://wiki.freepascal.org/Common_pr...C_header_files