View source for AIGLX

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{{short description|Open source project}}
[[File:Linux graphics drivers DRI current.svg|thumb|300px|[[GLX]] and '''AIGLX''' versus [[Direct Rendering Manager|direct rendering]].]]
[[Image:Fedora-Core-6-AIGLX.png|thumb|[[Compiz]] running on Fedora Core 6 with AIGLX.]]
'''Accelerated Indirect GLX'''  ("'''AIGLX'''") is an [[Open-source software|open source]] project founded by [[Red Hat]] and the [[Fedora (operating system)|Fedora]] community, led by [[Kristian Høgsberg]],<ref>{{cite web | url = http://archive.fosdem.org/2007/interview/kristian+hoegsberg.html | title = Interview: Kristian Høgsberg | date = 2007-02-06 | quote = Learn from AIGLX creator Kristian Høgsberg....}}</ref> to allow accelerated indirect [[GLX]] rendering capabilities to  the [[X.Org Server]] and [[Direct Rendering Infrastructure|DRI]] drivers. This allows remote X clients to get fully hardware accelerated rendering over the GLX protocol; coincidentally, this development was required for [[OpenGL]] [[compositing window manager]]s to function with hardware acceleration.

== Rationale ==
There are two ways in which a windowing system can allow an OpenGL implementation to talk to the graphics card.

The first is to specify the OpenGL command stream in a portable network-neutral manner using a client/server implementation similar to the X11 drawing routines.  This method, used by AIGLX, is indirect in that the drawing commands are sent to the X server and then the X server sends them along to the graphics card.

The second way, which is at the base of [[Xgl]], is to open a window and then allow the OpenGL library to send commands directly to the graphics card.

Accelerating the indirect OpenGL path is orthogonal to how the X server itself is implemented, but it has the side effect of allowing the OpenGL command stream to be more easily captured and redirected to a texture.  This allows Compiz and other [[compositing window manager]]s to be built on top of a traditional X server with a small extension rather than requiring a full Xgl server. This is also an advantage over [[Direct Rendering Infrastructure|DRI]] which bypasses the compositing engine even while providing hardware acceleration.

== Deployment ==
The AIGLX project was merged into X.Org and has been available with X.Org 7.1.

AIGLX needed driver support to run. Specifically, it depended on the {{samp|texture_from_pixmap}} [[OpenGL]] extension.

== Relationship to Xgl ==
Although the AIGLX project has features similar to [[Xgl]], it was not intended to be a competing product. According to the Fedora Project Wiki, the project was founded in part because Xgl was written during its final stages "behind closed doors." This lack of peer-review drew criticism claiming to be the root of flaws in the software. An agreement was reached to share the source code between the two projects under the premise that doing so would prevent compatibility conflicts. Xgl was removed from the X Server on June 12, 2008.<ref>[http://gitweb.freedesktop.org/?p=xorg/xserver.git;a=commit;h=d15b3790307053587df8daed1936ff6923881b63 XGL Version Info]</ref>

== History ==
<gallery>
File:Linux graphics drivers 2D.svg|2D drivers inside of the [[display server|X server]]
File:Linux graphics drivers Utah GLX.svg|Indirect rendering over [[GLX]], using [[Utah GLX]]
File:Linux graphics drivers DRI early.svg|early [[Direct Rendering Infrastructure]]
File:Linux graphics drivers DRI current.svg|Finally all access goes through the [[Direct Rendering Manager]]
File:Linux graphics drivers DRI Wayland.svg|In Linux kernel 3.12 ''render nodes'' were merged and the [[Kernel mode-setting|KMS]] was split off. [[Wayland (display server protocol)|Wayland]] implements direct rendering over [[EGL (API)|EGL]]
</gallery>

== See also ==
*[[Core OpenGL|CGL]] – the equivalent [[Mac OS X]] interface to OpenGL
*[[EGL (API)|EGL]] – the equivalent [[Wayland (display server protocol)|Wayland]] interface to [[OpenGL ES]] and [[OpenVG]] (Wayland is also being mainly developed by Kristian Høgsberg)
*[[GLX]] – the equivalent [[X11]] interface to OpenGL

== References ==
{{Reflist}}

== External links ==
* [http://fedoraproject.org/wiki/RenderingProject/aiglx Fedora Project Wiki AIGLX Article] — contains early demonstration videos in the free [[Theora|Ogg Theora]] format.

{{XWinSys}}

[[Category:Free software projects]]
[[Category:Freedesktop.org]]
[[Category:OpenGL]]