Gallium3D

Gallium3D is a set of interfaces and a collection of supporting libraries intended to ease the programming of device drivers for 3D graphics chipsets for multiple operating systems, rendering or video acceleration APIs.

The development of Gallium3D started in 2008 at Tungsten Graphics, and the implementation is available as free and open-source software as part of Mesa 3D hosted by freedesktop.org. The primary goal of making driver development easier, bundling otherwise duplicated code of several different drivers at a single point, and to support modern hardware architectures. This is done by providing a better division of labor, for example, leaving memory management to the kernel DRI driver.

Gallium3D has been a part of Mesa since 2009 and is currently used by the free and open-source graphics driver for Nvidia (nouveau project), for R300–R900, and for other free and open-source GPU device drivers.

Gallium3D eases programming of device drivers by splitting the graphics device driver into three parts. This is accomplished by the introduction of two interfaces: Gallium3D State Tracker Interface and the Gallium3D WinSys Interface. The three components are called:

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 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. 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.