


Gimp(3)        User Contributed Perl Documentation        Gimp(3)


NAME
       Gimp - Perl extension for writing Gimp Extensions/Plug-
       ins/Load & Save-Handlers

RATIONALE
       Well, scheme (which is used by script-fu), is IMnsHO the
       crappiest language ever (well, the crappiest language that
       one actually can use, so it's not _that_ bad). Scheme has
       the worst of all languages, no data types, but still using
       variables. Look at haskell to see how functional is done
       right.

       I'd loved to write a haskell interface instead, but it was
       sooo much easier in perl (at least for me..), so here's
       the Gimp <-> Perl interface, mostly a direct libgimp
       interface. Needless to say, it was (is) very instructive,
       too.

SYNOPSIS
         use Gimp;

         Other modules of interest:

         use Gimp::Util;
         use Gimp::OO;

         these have their own manpage.


       IMPORT TAGS

       If you don't give an interface= hint, we will guess a
       default which might be wrong in future versions of the
       Gimp, so watch out!

       :auto
           Import useful constants, like RGB,
           RUN_NONINTERACTIVE... as well as all libgimp and pdb
           functions automagically into the caller's namespace.
           BEWARE!  This will overwrite your AUTOLOAD function,
           if you have one!

       interface=lib
           Use direct interface via libgimp.

       interface=net
           Use network interface using Net-Server and Gimp::Net.

       (ignore this section for now... ;) this will eventually
       contain some minimal plug-in examples)

       use Gimp qw( :auto );

       sub net {



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Gimp(3)        User Contributed Perl Documentation        Gimp(3)


         gimp_quit; }

       exit gimp_main;

DESCRIPTION
       Sorry, I didn't make a very useful documentation yet..
       help appreciated!

       Look at the sample plug-ins that come with this module. If
       you write other plug-ins, send them to me! If you have
       question on use, you might as well ask me (although I'm a
       busy man, so be patient, or wait for the next version ;)

       It might also prove useful to know how a plug-in is
       written in C, so have a look at some existing plug-ins in
       C!

       Anyway, feedback is appreciated, otherwise, I won't
       publish future version.

       And have a look at the other modules, Gimp::Util and
       Gimp::OO, and maybe the interface modules Gimp::Lib and
       Gimp::Net.

       Some highlites:

       o Networked plug-ins and plug-ins using the libgimp
         interfaces (i.e. to be started by The Gimp) are written
         alsmot the same way, you can easily create hybrid
         (network & libgimp) scripts as well.

       o Use either a plain pdb (scheme-like) interface or nice
         object- oriented syntax, i.e.
         """"gimp_layer_new(600,300,RGB)"""" is the same as
         """"new Image(600,300,RGB)""""

       noteworthy limitations (subject to be changed):

       o callback procedures do not return anything to The Gimp,
         not even a status argument, which seems to be mandatory
         by the gimp protocol (which is nowhere standardized,
         though).

       o The tile and region functions are not yet supported.

CALLBACKS
       init (), query (), quit (), <installed_procedure>()
           the standard libgimp callback functions. run() is
           missing, because this module will directly call the
           function you registered with gimp_install_procedure.

       net ()
           this is called when the plug-in is not started from
           within Gimp, but is using Net-Server (the perl network



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Gimp(3)        User Contributed Perl Documentation        Gimp(3)


           server extension you hopefully have installed and
           started ;)

FUNCTIONS
       set_trace (tracemask)
           Tracking down bugs in gimp scripts is difficult: no
           sensible error messages.  If anything goes wrong, you
           only get an execution failure. Switch on tracing to
           see which parameters are used to call pdb functions.

           This function is never exported, so you have to
           qualify it when calling.  (not yet implemented for
           networked modules).

           tracemask is any number of the following flags or'ed
           together.

       TRACE_NONE  nothing is printed.

       TRACE_CALL  all pdb calls (and only pdb calls!) are
                   printed with arguments and return values.

       TRACE_TYPE  the parameter types are printed additionally.

       TRACE_NAME  the parameter names are printed.

       TRACE_DESC  the parameter descriptions.

       TRACE_ALL   all of the above.

       set_trace(\$tracevar)
           write trace into $tracevar instead of printing it to
           STDERR. $tracevar only contains the last command
           traces, i.e. it's cleared on every gimp_call_procedure
           invocation.

       set_trace(*FILEHANDLE)
           write trace to FILEHANDLE instead of STDERR.

       gimp_main()
           Should be called immediately when perl is initialized.
           Arguments are not yet supported. Initializations can
           later be done in the init function.

       gimp_install_procedure(name, blurb, help, author,
           copyright, date, menu_path, image_types, type,
           [params], [return_vals])
           Mostly same as gimp_install_procedure. The parameters
           and return values for the functions are specified as
           an array ref containing either integers or array-refs
           with three elements, [PARAM_TYPE, \"NAME\",
           \"DESCRIPTION\"].





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Gimp(3)        User Contributed Perl Documentation        Gimp(3)


       gimp_progress_init(message)
           Initializes a progress bar. In networked modules this
           is a no-op.

       gimp_progress_update(percentage)
           Updates the progress bar. No-op in networked modules.

       Some functions that have a different calling convention
       than pdb functions but the same name are not visible in
       the perl module. (i.e. pdb functions have priority on name
       clashes)

SUPPORTED GIMP DATA TYPES
       Gimp supports different data types like colors, regions,
       strings. In perl, these are represented as:

       INT32, INT16, INT8, FLOAT, STRING
           normal perl scalars. Anything except STRING will be
           mapped to a perl-double.

       INT32ARRAY, INT16ARRAY, INT8ARRAY, FLOATARRAY, STRINGARRAY
           array refs containing scalars of the same type, i.e.
           [1, 2, 3, 4].  (not yet supported).

       COLOR
           on input, either an array ref with 3 elements (i.e.
           [233,40,40]) or a X11-like string is accepted
           ("#rrggbb").

       REGION
           Not yet supported.

       DISPLAY, IMAGE, LAYER, CHANNEL, DRAWABLE, SELECTION
           These will be mapped to corresponding objects (IMAGE
           => Gimp::Image). In trace output you will see small
           integers (the image/layer/etc..-ID)

       BOUNDARY, PATH, STATUS
           Not yet supported.

PLEASE
       if you get this far while reading the manpage, please
       consider helping me with the documentation, or write
       scripts etc... ;) thanks!

AUTHOR
       Marc Lehmann, pcg@goof.com

SEE ALSO
       perl(1), gimp(1), Gimp:OO, Gimp::Data, Gimp::Util.







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Gimp(3)        User Contributed Perl Documentation        Gimp(3)



























































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