let cmd_dvips tmpprefix = "dvips -R -E " ^ tmpprefix ^ ".dvi -f >" ^ tmpprefix ^ ".ps" let cmd_latex tmpprefix = "latex " ^ tmpprefix ^ ".tex >/dev/null" (* Putting -transparent white in converts arguments will sort-of give you transperancy *) let cmd_convert tmpprefix finalpath = "convert -quality 100 -density 120 " ^ tmpprefix ^ ".ps " ^ finalpath ^ " >/dev/null 2>/dev/null" (* Putting -bg Transparent in dvipng's arguments will give full-alpha transparency *) (* Note that IE have problems with such PNGs and need an additional javascript snippet *) (* Putting -bg transparent in dvipng's arguments will give binary transparency *) let cmd_dvipng tmpprefix finalpath = "dvipng -gamma 1.5 -D 120 -T tight --strict " ^ tmpprefix ^ ".dvi -o " ^ finalpath ^ " >/dev/null 2>/dev/null" exception ExternalCommandFailure of string let render tmppath finalpath outtex md5 = let tmpprefix0 = (string_of_int (Unix.getpid ()))^"_"^md5 in let tmpprefix = (tmppath^"/"^tmpprefix0) in let unlink_all () = begin (* Commenting this block out will aid in debugging *) Sys.remove (tmpprefix ^ ".dvi"); Sys.remove (tmpprefix ^ ".aux"); Sys.remove (tmpprefix ^ ".log"); Sys.remove (tmpprefix ^ ".tex"); if Sys.file_exists (tmpprefix ^ ".ps") then Sys.remove (tmpprefix ^ ".ps"); end in let f = (Util.open_out_unless_exists (tmpprefix ^ ".tex")) in begin output_string f (Texutil.get_preface ()); output_string f outtex; output_string f (Texutil.get_footer ()); close_out f; if Util.run_in_other_directory tmppath (cmd_latex tmpprefix0) != 0 then (unlink_all (); raise (ExternalCommandFailure "latex")) else if (Sys.command (cmd_dvipng tmpprefix (finalpath^"/"^md5^".png")) != 0) then (if (Sys.command (cmd_dvips tmpprefix) != 0) then (unlink_all (); raise (ExternalCommandFailure "dvips")) else if (Sys.command (cmd_convert tmpprefix (finalpath^"/"^md5^".png")) != 0) then (unlink_all (); raise (ExternalCommandFailure "convert")) else unlink_all ()) else unlink_all () end