DirectFB
Encyclopedia
DirectFB stands for Direct Frame Buffer. It is a software library
for GNU
/Linux
/Unix
-based operating system
s with a small memory footprint
that provides graphics acceleration, input device
handling and abstraction layer
, and integrated windowing system
with support for translucent windows and multiple display layers on top of the Linux framebuffer
without requiring any kernel
modifications. DirectFB is free software licensed under the terms of the GNU Lesser General Public License
(LGPL).
The library allows developers an alternative to a full X Window System
(X11) server used in Unix-like
operating system
s. DirectFB allows applications to talk directly to video hardware through a direct API
, speeding up and simplifying graphic operations.
It is often used by games and embedded system
s developers to circumvent the overhead of a full X Window System
server implementation. In 2006, a version of DirectFB was included in the software stack for the CE Linux Forum
's Audio/Video Graphics Specification V2.
DirectFB can host XDirectFB, a rootless X server implementation that uses DirectFB windows for X11 top-level windows. XDirectFB is an interface that mimics the X11 interface through the DirectFB API to simplify running applications written for X11 on DirectFB.
DirectFBGL is an OpenGL
extension for DirectFB/XDirectFB that uses Direct Rendering Infrastructure
(DRI) in the Mesa 3D
library to support OpenGL hardware acceleration.
Among the products that use DirectFB are LinuxTV
, the unreleased Palm Foleo
mobile companion, the webOS operating system and the Philips
TVs based on jointSPACE.
Library (computer science)
In computer science, a library is a collection of resources used to develop software. These may include pre-written code and subroutines, classes, values or type specifications....
for GNU
GNU
GNU is a Unix-like computer operating system developed by the GNU project, ultimately aiming to be a "complete Unix-compatible software system"...
/Linux
Linux
Linux is a Unix-like computer operating system assembled under the model of free and open source software development and distribution. The defining component of any Linux system is the Linux kernel, an operating system kernel first released October 5, 1991 by Linus Torvalds...
/Unix
Unix
Unix is a multitasking, multi-user computer operating system originally developed in 1969 by a group of AT&T employees at Bell Labs, including Ken Thompson, Dennis Ritchie, Brian Kernighan, Douglas McIlroy, and Joe Ossanna...
-based operating system
Operating system
An operating system is a set of programs that manage computer hardware resources and provide common services for application software. The operating system is the most important type of system software in a computer system...
s with a small memory footprint
Memory footprint
Memory footprint refers to the amount of main memory that a program uses or references while running.This includes all sorts of active memory regions like code, static data sections , heap, as well as all the stacks, plus memory required to hold any additional data structures, such as symbol...
that provides graphics acceleration, input device
Input device
In computing, an input device is any peripheral used to provide data and control signals to an information processing system such as a computer or other information appliance...
handling and abstraction layer
Abstraction layer
An abstraction layer is a way of hiding the implementation details of a particular set of functionality...
, and integrated windowing system
Windowing system
A windowing system is a component of a graphical user interface , and more specifically of a desktop environment, which supports the implementation of window managers, and provides basic support for graphics hardware, pointing devices such as mice, and keyboards...
with support for translucent windows and multiple display layers on top of the Linux framebuffer
Linux framebuffer
The Linux framebuffer is a graphic hardware-independent abstraction layer to show graphics on a computer monitor, typically on the console...
without requiring any kernel
Kernel (computing)
In computing, the kernel is the main component of most computer operating systems; it is a bridge between applications and the actual data processing done at the hardware level. The kernel's responsibilities include managing the system's resources...
modifications. DirectFB is free software licensed under the terms of the GNU Lesser General Public License
GNU Lesser General Public License
The GNU Lesser General Public License or LGPL is a free software license published by the Free Software Foundation . It was designed as a compromise between the strong-copyleft GNU General Public License or GPL and permissive licenses such as the BSD licenses and the MIT License...
(LGPL).
The library allows developers an alternative to a full X Window System
X Window System
The X window system is a computer software system and network protocol that provides a basis for graphical user interfaces and rich input device capability for networked computers...
(X11) server used in Unix-like
Unix-like
A Unix-like operating system is one that behaves in a manner similar to a Unix system, while not necessarily conforming to or being certified to any version of the Single UNIX Specification....
operating system
Operating system
An operating system is a set of programs that manage computer hardware resources and provide common services for application software. The operating system is the most important type of system software in a computer system...
s. DirectFB allows applications to talk directly to video hardware through a direct API
Application programming interface
An application programming interface is a source code based specification intended to be used as an interface by software components to communicate with each other...
, speeding up and simplifying graphic operations.
It is often used by games and embedded system
Embedded system
An embedded system is a computer system designed for specific control functions within a larger system. often with real-time computing constraints. It is embedded as part of a complete device often including hardware and mechanical parts. By contrast, a general-purpose computer, such as a personal...
s developers to circumvent the overhead of a full X Window System
X Window System
The X window system is a computer software system and network protocol that provides a basis for graphical user interfaces and rich input device capability for networked computers...
server implementation. In 2006, a version of DirectFB was included in the software stack for the CE Linux Forum
CE Linux Forum
The Consumer Electronics Linux Forum is a non-profit organization that works to advance Linux as an open source platform for consumer electronics devices...
's Audio/Video Graphics Specification V2.
DirectFB can host XDirectFB, a rootless X server implementation that uses DirectFB windows for X11 top-level windows. XDirectFB is an interface that mimics the X11 interface through the DirectFB API to simplify running applications written for X11 on DirectFB.
DirectFBGL is an OpenGL
OpenGL
OpenGL is a standard specification defining a cross-language, cross-platform API for writing applications that produce 2D and 3D computer graphics. The interface consists of over 250 different function calls which can be used to draw complex three-dimensional scenes from simple primitives. OpenGL...
extension for DirectFB/XDirectFB that uses Direct Rendering Infrastructure
Direct Rendering Infrastructure
In computing, the Direct Rendering Infrastructure is an interface and a free software implementation used in the X Window System to securely allow user applications to access the video hardware without requiring data to be passed through the X server. Its primary application is to provide...
(DRI) in the Mesa 3D
Mesa 3D
Mesa 3D is an open source 3D computer graphics library that provides a generic OpenGL implementation for rendering three-dimensional graphics on multiple platforms. It was initially developed by Brian Paul in August 1993, and is still maintained by him today...
library to support OpenGL hardware acceleration.
Among the products that use DirectFB are LinuxTV
LinuxTV
The LinuxTV project is an informal group of volunteers who develop software related to digital television for the Linux operating system. The community develops and maintains the DVB driver subsystem which is part of the Linux 2.6.x kernel...
, the unreleased Palm Foleo
Palm Foleo
The Palm Foleo was a planned subnotebook computer that was announced by mobile device manufacturer Palm Inc. on May 30, 2007, and canceled three months later. It intended to serve as a companion for smartphones including Palm's own Treo line...
mobile companion, the webOS operating system and the Philips
Philips
Koninklijke Philips Electronics N.V. , more commonly known as Philips, is a multinational Dutch electronics company....
TVs based on jointSPACE.
See also
- X.Org ServerX.Org ServerX.Org Server refers to the X server release packages stewarded by the X.Org Foundation,which is hosted by freedesktop.org, and grants...
- Crank Storyboard SuiteCrank Storyboard SuiteCrank Storyboard Suite is an Eclipse-based graphical user interface builder called Storyboard Designer and a target runtime called Storyboard Engine.- History and development :...