Hi.

This will help you build a shared library that will let you display mixed languages like Arabic and Latin characters in the proper visual way. 
''FriBidi'' is the library which does it.


****Required Debian packages****


   1. apt-get install swig ; ''swig'' is the one that can let us use any C/C++ library and transform its methods and functions into Tcl commands, Perl functions, PHP functions.
   2. apt-get install libfribidi-dev ; we need this to build the Tcl version of FriBiDi
   3. apt-get install tcl8.6-dev ; Swig needs this to include the Tcl bindings and make us the Tcl commands; If you have ActiveTcl installed you don't need this. Please don't confine yourself to version 8.6 .. check if it works too for 8.5. I think it must.


****Building steps****

select one and only one of the following 3 options:
   
If you use tcl8.5-dev package then type in the terminal:  
   tcl_include=/usr/include/tcl8.5/

If you use tcl8.6-dev package then type in the terminal:  
   tcl_include=/usr/include/tcl8.6/
  
If you use ActiveTcl 8.6 package then type in the terminal:
   tcl_include=/opt/ActiveTcl-8.6/include/

So I ask you to change the version of Tcl accordingly.

And then open a new ascii text file, using a text editor like gEdit or vi or kate. Name the file ''fribidi.i''.

Add the following instructions used by ''swig'' to ''fribidi.i''

  %module fribidi
  %{
   #include <fribidi/fribidi.h>
  %}

  %include "/usr/include/fribidi/fribidi-common.h";
  %include "/usr/include/fribidi/fribidi-unicode.h";
  %include "/usr/include/fribidi/fribidi-types.h";
  %include "/usr/include/fribidi/fribidi-flags.h";
  %include "/usr/include/fribidi/fribidi-bidi-types.h";
  %include "/usr/include/fribidi/fribidi-bidi.h";
  %include "/usr/include/fribidi/fribidi-joining-types.h";
  %include "/usr/include/fribidi/fribidi-joining.h";
  %include "/usr/include/fribidi/fribidi-mirroring.h";
  %include "/usr/include/fribidi/fribidi-arabic.h";
  %include "/usr/include/fribidi/fribidi-shape.h";
  %include "/usr/include/fribidi/fribidi-char-sets.h";
  %include "/usr/include/fribidi/fribidi-deprecated.h";
  %include "/usr/include/fribidi/fribidi-begindecls.h";
  %include "/usr/include/fribidi/fribidi-enddecls.h";
                                                    
Run the following command:
  swig -tcl fribidi.i

This will produce a new file named ''fribidi_wrap.c'' in the current directory. 

The following is warning that will result from using ''swig''. Ignore the warning:
  /usr/include/fribidi/fribidi-unicode.h:55: Warning 451: Setting a const char * variable may leak memory

Then generate the object file ''free_wrap.o'' by compiling ''fribidi_wrap.c''. Read carefully:

If you are on ''32 bit'' system, run the following command on the terminal:
 gcc -c fribidi_wrap.c -o fribidi_wrap.o -I $tcl_include

If you are on ''64 bit'' system, run the following command on the terminal. Notice that we added the option ''-fPIC'':
 gcc -c fribidi_wrap.c -o fribidi_wrap.o -I $tcl_include -fPIC

finally we can get our shared library as the file ''fribidi_tcl.so'', run the following command on the terminal :
   gcc -Wall -shared -I $tcl_include  fribidi_wrap.o -lm -lfribidi -o fribidi_tcl.so

Then in your Tcl code, you may use ''fribidi_tcl.so'' using the [load] command:
 load fribidi_tcl.so

To see all the commands provided by ''fribidi_tcl.so'', run the following command on the terminal
  nm fribidi_tcl.so | more

The tcl terminal ''tkcon'' can also help in listing some of fribidi commands. Only type ''fribidi'' and use text completion by pressing the TAB key twice.
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