Direct rendering infrastructure

The Linux graphics stack with the Direct Rendering Manager

The Direct Rendering Infrastructure (abbreviated DRI ) is a framework for Unix-like operating systems , which is supposed to enable the most direct, yet secure and stable access to 3D accelerators . The name comes from the fact that indirect rendering , for example via the GLX protocol, has been replaced.

Software architecture

The DRI consists of the kernel module Direct Rendering Manager (DRM), which provides an interface to the graphics card , and components in the user space that access it. The latter part of the DRI provides a hardware-accelerated back-end for Mesa and translates the application's commands into hardware-specific commands, which it sends to the graphics card via the DRM.

DRI2

Since 2007, the development of a successor version of DRI has been driven forward, which eliminates several weaknesses of DRI, especially in conjunction with AIGLX . At the beginning of 2008 the first DRI2 graphics drivers were added to the X.Org server's developer tree.

DRI3

DRI3 was released on November 1, 2013. It contains numerous changes from DRI2.

Driver support

DRI is supported by almost all free drivers in the X.Org server and in XFree86 . Some proprietary drivers such as AMD / ATI also support DRI.

history

There were only 2D drivers, and these were also part of the X server
Only indirect image synthesis via the GLX protocol was possible; there were also Utah GLX drivers
Early direct rendering infrastructure
Hardware access is only via the Direct Rendering Manager possible
In Linux kernel 3.12, render nodes were introduced and the KMS was split off. Wayland implements direct rendering through EGL .