Editing Mesa (computer graphics) (section)

==== Differences from classic graphics drivers ====

Gallium3D provides a unified [[API]] exposing standard hardware functions, such as [[shader]] units found on modern hardware. Thus, 3D APIs such as [[OpenGL]] 1.x/2.x, OpenGL 3.x, [[OpenVG]], [[GPGPU]] infrastructure or even [[Direct3D]] (as found in the [[Wine (software)|Wine]] compatibility layer) will need only a single back-end, called a state tracker, targeting the Gallium3D API. By contrast, classic-style DRI device drivers require a different back-end for each hardware platform and several other APIs need translation to OpenGL at the expense of code duplication.<ref>{{cite web
 |url        = http://www.tungstengraphics.com/technologies/gallium3d.html
 |archive-url = https://web.archive.org/web/20080503021058/http://www.tungstengraphics.com/technologies/gallium3d.html
 |url-status   = dead
 |archive-date = 3 May 2008
 |title      = TG-Gallium3D
 |publisher  = Tungsten Graphics
 |access-date = 1 April 2008
}}</ref><ref>{{cite web
|url = http://zrusin.blogspot.com/2008/02/gpgpu.html
|title = GPGPU
|last = Rusin
|first = Zack
|date = 6 February 2008
|access-date = 1 April 2008
}}</ref><ref>{{cite web
|url = http://zrusin.blogspot.com/2008/02/openvg-and-accelerating-2d.html
|title = OpenVG and accelerating 2D
|last = Rusin
|first = Zack
|date = 7 February 2008
|access-date = 1 April 2008
}}</ref> All vendor device drivers, due to their proprietary and closed-source nature, are written that way meaning that, e.g. the [[AMD Catalyst]] implements both [[OpenGL]] and [[Direct3D]], and the vendor drivers for the [[GeForce]] have their implementations.

Under Gallium3D, [[Direct Rendering Manager]] (DRM) kernel drivers will manage the memory and [[Direct Rendering Infrastructure|Direct Rendering Interface]] (DRI2) drivers will be more GPU processing oriented.<ref>{{cite web
 |url         = http://wiki.x.org/wiki/DRI2
 |title       = DRI2
 |date        = 4 October 2007
 |access-date  = 1 April 2008
 |url-status     = dead
 |archive-url  = https://web.archive.org/web/20080704122122/http://wiki.x.org/wiki/DRI2
 |archive-date = 4 July 2008
 |df          = dmy-all
}}</ref> During the transition period from userspace modesetting to kernelspace modesetting some of the Mesa 3D drivers, such as the radeon driver or Intel's drivers, ended up supporting both DRI1 and DRI2 and used DRI2 if available on the system. Gallium3D additionally requires a level of shader support that is not available on older cards like e.g. ATi r100-r200 so users for those cards need to keep using Mesa 3D with DRI2 for their 3D usage.