|Original author(s)||GIMP authors|
|Developer(s)||The GNOME Project|
|Stable release||3.12.2 (May 20, 2014[±])|
|Preview release||3.13.4 (July 25, 2014 ) [±]|
|Operating system||Linux, OS X, Microsoft Windows|
|Platform||X11, Wayland, others|
|License||GNU Lesser General Public License (LGPL)|
GDK (GIMP Drawing Kit) is a library that acts as a wrapper around the low-level functions provided by the underlying windowing and graphics systems. GDK lies between the display server and the GTK+ library, handling basic rendering such as drawing primitives, raster graphics (bitmaps), cursors, fonts, as well as window events and drag-and-drop functionality.
Like GTK+, GDK is licensed under the GNU Lesser General Public License (LGPL).
GTK+ is implemented on top of an abstraction layer called GDK, freeing GTK+ from low-level concerns like input gathering and pixel format conversion.
GDK is an important part of GTK+'s portability. Since low-level cross-platform functionality is already provided by GLib, all that is needed to make GTK+ run on other platforms is to port GDK to the underlying operating system's graphics layer. Hence, the GDK ports to the Windows API and Quartz are what makes GTK+ applications run on Windows and OS X, respectively.
GDK is an intermediate layer which isolates GTK+ from the details of the windowing system. GDK is a thin wrapper around Xlib. The X Window System comes with a low-level library called Xlib. Almost every function in GDK is a very thin wrapper around a corresponding Xlib function; but some of the complexity (and functionality) of Xlib is hidden, to simplify programming and to make GDK easier to port to other windowing systems, such as Wayland or Microsoft Windows. The concealed Xlib functionality will rarely be of interest to application programmers; for example, many features used solely by window managers are not exposed in GDK.
GDK lets you do low level stuff, like e.g. "blit this pixmap to the screen".
GDK provides a layer that is much more portable than say the X protocol, without sacrificing any of the low-level accessibility that systems such as X provide. The true power of this abstraction is that if you choose to use it rather than say, X, your software will automatically render on the Linux Framebuffer and Windows.
Canvas (Scene graph)
In its history GDK contained and linked with a couple of different Canvases.
- Graphene is the forthcoming GTK+ scene graph (canvas) API.
Developers are also considering new directions for the library, including removing deprecated API components and adding an integrated scene graph (canvas) system, similar to the Clutter graphics library, effectively integrating GTK+ with OpenGL.
GdkPixbuf is a toolkit for image loading and pixel buffer manipulation. In GTK+ version 2.22 from 2010-09-23 GdkPixbuf was split off from GDK into a separate package in preparation for the transition to GTK+ 3.
- "GNOME 3.12.1 release notes". GNOME mailing list. 2014-04-17. Retrieved 2014-06-19.
- Jardón, Javier (July 25, 2014). "GNOME 3.13.4". gnome-announce mailing list. https://mail.gnome.org/archives/gnome-announce-list/2014-July/msg00017.html. Retrieved July 27, 2014.
- "Graphene". 2014-05-02.
- Alberto Ruiz's Blog
- Havoc Pennington's scene graph proposal
- GDK code from release GTK+ 2.16.0