Build Status MetaCPAN Release


Alien::FLTK - Build and use the stable 1.3.x branch of the Fast Light Toolkit


This distribution builds and installs libraries for the (stable) 1.3.x branch of the FLTK GUI toolkit.


use Alien::FLTK;
use ExtUtils::CBuilder;
my $AF  = Alien::FLTK->new();
my $CC  = ExtUtils::CBuilder->new();
my $SRC = 'hello_world.cxx';
open(my $FH, '>', $SRC) || die '...';
syswrite($FH, <<'') || die '...'; close $FH;
  #include <FL/Fl.H>
  #include <FL/Fl_Window.H>
  #include <FL/Fl_Box.H>
  int main(int argc, char **argv) {
    Fl_Window *window = new Fl_Window(300,180);
    Fl_Box *box = new Fl_Box(FL_UP_BOX, 20, 40, 260, 100, "Hello, World!");
    box->labelfont(FL_BOLD + FL_ITALIC);
    window->show(argc, argv);
    return Fl::run();

my $OBJ = $CC->compile('C++'                => 1,
                       source               => $SRC,
                       include_dirs         => [$AF->include_dirs()],
                       extra_compiler_flags => $AF->cxxflags()
my $EXE =
     objects            => $OBJ,
     extra_linker_flags => '-L' . $AF->library_path . ' ' . $AF->ldflags()
print system('./' . $EXE) ? 'Aww...' : 'Yay!';
END { unlink grep defined, $SRC, $OBJ, $EXE; }


There are no per-object configuration options as of this version, but there may be in the future, so any new code using Alien::FLTK should create objects with the new constructor.

my $AF = Alien::FLTK->new( );


After creating a new Alien::FLTK object, use the following methods to gather information:


my @include_dirs = $AF->include_dirs( );

Returns a list of the locations of the headers installed during the build process and those required for compilation.


my $lib_path = $AF->library_path( );

Returns the location of the private libraries we made and installed during the build process.


my $cflags = $AF->cflags( );

Returns additional C compiler flags to be used.


my $cxxflags = $AF->cxxflags( );

Returns additional flags to be used to when compiling C++ using FLTK.


my $ldflags = $AF->ldflags( qw[gl images] );

Returns additional linker flags to be used. This method can automatically add appropriate flags based on how you plan on linking to fltk. Acceptable arguments are:

  • gl

    Include flags to use GL.

    This is an experimental option. Depending on your system, this may also include OpenGL or MesaGL.

  • images

    Include flags to use extra image formats (PNG, JPEG).



Prerequisites differ by system...

  • Win32

    The fltk libs and Alien::FLTK both build right out of the box with MinGW. Further testing is needed for other setups.

  • X11/*nix

    X11-based systems require several development packages. On Debian, these may be installed with:

    > sudo apt-get install libx11-dev
    > sudo apt-get install libxi-dev

    Additionally, the optional XCurser lib may be installed with:

    > sudo apt-get install libxcursor-dev
  • Darwin/OSX

    Uh, yeah, I have no idea.


The distribution is based on Module::Build, so use the following procedure:

> perl Build.PL
> ./Build
> ./Build test
> ./Build install
  • Issue Tracker

    Please only report Alien::FLTK related bugs to this tracker. For FLTK issues, use

  • Commit Log

  • Homepage: is the homepage of the FLTK project.

  • License:

    See the License and Legal section of this document.

  • Mailing List

    Once I find someone to host a list for the FLTK project, I'll use it for Alien::FLTK too.

  • Repository and you are invited to fork it.


Please see the Synopsis and the files in the /examples/.


Numerous, I'm sure.

To Do

Please see Alien::FLTK::Todo

See Also

FLTK, Alien::FLTK2


  • The FLTK Team -


Sanko Robinson -


License and Legal

Copyright (C) 2009-2020 by Sanko Robinson

This program is free software; you can redistribute it and/or modify it under the terms of The Artistic License 2.0. See the LICENSE file included with this distribution or For clarification, see

When separated from the distribution, all POD documentation is covered by the Creative Commons Attribution-Share Alike 3.0 License. See For clarification, see

Alien::FLTK is based in part on the work of the FLTK project. See