gltk is a C++ Widget library built on GLUT. The API of gltk is modeled after gtkmm, the C++ interface of the GTK+ library. The implementation of gltk was inspired by GLUI. By building on GLUT, the library is readily ported to platforms where GLUT (or FreeGLUT) is available. These include Linux, Windows, and Mac OS X.
A loose goal of gltk is to be API compatible with gtkmm, where people
can, ideally, replace the Gtk namespace by
gltk and have their programs compile and run on platforms
where gtkmm is not available. Under the limitation of GLUT, such goal
can only be filled partially. In reality, this project only aims for
a close approximation to the most commonly used part of the API, so
the author does not have to rewrite his existing gtkmm codes to make
his programs portable with GLUT.
Following gtkmm, the communication between objects in the library is
provided by the signal-slot API of
libsigc++. While
libsigc++ is readily ported to a wide range of platforms, to minimize
the prerequisites of gltk, a very limited, in-house substitute of
libsigc++, under the same sigc namespace, is provided in
the header sigc.hh with the aim of making it
source-compatible with libsigc++. The users of the library may replace
sigc.hh with the real libsigc++ when it's available to
gain flexibility and performance.