math/render.ml

   1 let cmd_dvips tmpprefix = "dvips -q -R -E " ^ tmpprefix ^ ".dvi -f >" ^ tmpprefix ^ ".ps"
   2 let cmd_latex tmpprefix = "latex " ^ tmpprefix ^ ".tex >/dev/null"
   3 (* Putting -transparent white in converts arguments will sort-of give you transperancy *)
   4 let cmd_convert tmpprefix finalpath = "convert -quality 100 -density 120 " ^ tmpprefix ^ ".ps " ^ finalpath ^ " >/dev/null 2>/dev/null"
   5 (* Putting -bg Transparent in dvipng's arguments will give full-alpha transparency *)
   6 (* Note that IE have problems with such PNGs and need an additional javascript snippet *)
   7 (* Putting -bg transparent in dvipng's arguments will give binary transparency *)
   8 let cmd_dvipng tmpprefix finalpath = "dvipng -gamma 1.5 -D 120 -T tight --strict " ^ tmpprefix ^ ".dvi -o " ^ finalpath ^ " >/dev/null 2>/dev/null"
   9
  10 exception ExternalCommandFailure of string
  11
  12 let render tmppath finalpath outtex md5 =
  13     let tmpprefix0 = (string_of_int (Unix.getpid ()))^"_"^md5 in
  14     let tmpprefix = (tmppath^"/"^tmpprefix0) in
  15     let unlink_all () =
  16       begin
  17         (* Commenting this block out will aid in debugging *)
  18         Sys.remove (tmpprefix ^ ".dvi");
  19         Sys.remove (tmpprefix ^ ".aux");
  20         Sys.remove (tmpprefix ^ ".log");
  21         Sys.remove (tmpprefix ^ ".tex");
  22         if Sys.file_exists (tmpprefix ^ ".ps")
  23         then Sys.remove (tmpprefix ^ ".ps");
  24       end in
  25     let f = (Util.open_out_unless_exists (tmpprefix ^ ".tex")) in
  26       begin
  27         output_string f (Texutil.get_preface ());
  28         output_string f outtex;
  29         output_string f (Texutil.get_footer ());
  30         close_out f;
  31         if Util.run_in_other_directory tmppath (cmd_latex tmpprefix0) != 0
  32         then (unlink_all (); raise (ExternalCommandFailure "latex"))
  33         else if (Sys.command (cmd_dvipng tmpprefix (finalpath^"/"^md5^".png")) != 0)
  34         then (if (Sys.command (cmd_dvips tmpprefix) != 0)
  35         then (unlink_all (); raise (ExternalCommandFailure "dvips"))
  36         else if (Sys.command (cmd_convert tmpprefix (finalpath^"/"^md5^".png")) != 0)
  37         then (unlink_all (); raise (ExternalCommandFailure "convert"))
  38         else unlink_all ())
  39         else unlink_all ()
  40       end