Mesa (computer graphics)

An open-source effort to write a Mesa Nvidia driver called Nouveau is developed mostly by the community.

Besides 3D applications such as games, modern display servers (X.org's Glamor or Wayland's Weston) use OpenGL/EGL; therefore all graphics typically go through Mesa.

Mesa was subsequently widely adopted and now contains numerous contributions from various individuals and corporations worldwide, including from the graphics hardware manufacturers of the Khronos Group that administer the OpenGL specification.

Permanent work is possible completion of Features and Optimization of drivers for older hardware like AMD R600/Evergreen, Nvidia Tesla and before, Fermi, Kepler or Intel Sandybridge, Ivybridge, Haswell or Broadwell.

ARM Architecture made also great improvements in Adreno 3xx/4xx/5xx and Broadwell VC4/VC5 for Raspi with main target OpenGL ES.

Google VirtIO GPU Driver Venus with Vulkan 1.2+ is merged in experimental state with low performance in mesa main tree.

[53] An old plan is to split old drivers in a classic tree with many advantages in programming, support, bug fixing for the modern gallium 3D part.

[54] A new Gallium3D driver Crocus for Intel Gen 4 Graphics to Haswell is here in development to complete here the gallium3D area with possible split in the next time of year 2021.

[57] Microsoft introduces new driver „Dozen“ for WSL 2 in early development stage as Vulkan over d3d12 in Mesa 22.1.

Vulkan breaks compatibility with OpenGL and completely abandons its monolithic state machine concept.

Similarly there is no technical reason to flange it with NIR, but yet Intel's employees implemented their Vulkan driver that way.

Mesa Software Driver VIRGL starts Vulkan Development in 2018 with GSOC projects for support of Virtual machines.

At XDC2014, Nvidia employee Andy Ritger proposed to enhance EGL in order to replace GBM.

Due to patent concerns regarding the H.264, H.265 and VC-1 video codecs, Fedora Linux disabled support for VAAPI acceleration for those in its build of Mesa in September 2022.

[129] With adapting to DRI, the Mesa library finally took over the role of the front end component of a full scale OpenGL framework with varying backend components that could offer different degrees of 3D hardware support while not dropping the full software rendering capability.

[134] Mesa also contains an implementation of software rendering called swrast that allows shaders to run on the CPU as a fallback when no graphics hardware accelerators are present.

The Gallium software rasterizer is known as softpipe or when built with support for LLVM llvmpipe, which generates CPU code at runtime.

In Mesa 12.0 a new Intel Rasterizer OpenSWR is available with high advantages in clusters for large data sets.

Matt Turner said it was much easier to fix this in the translator program than having to make Mesa's compiler carry the burden of dealing with such bloated shaders.

[150][151] NIR was extended in last and actual releases as base of Spir-V support and is since 2016 main development area.

NIR is now Main development area, so TGSI is only for older driver like r300g default infrastructure and will be deprecated in some years.

Gallium3D is a set of interfaces and a collection of supporting libraries[154] 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,[155] and the implementation is available as free and open-source software as part of Mesa 3D hosted by freedesktop.org.

This is done by providing a better division of labor, for example, leaving memory management to the kernel DRI driver.

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.

In addition, using the modular structure of Gallium3D, there is an effort underway to use the LLVM compiler suite and create a module to optimize shader code on the fly.

Original authors of Gallium3D were Keith Whitwell and Brian Paul at Tungsten Graphics (acquired by VMware in 2008).

2011-11-30: Intel 965g and Cell Gallium drivers were removed from the master branch of Mesa as unmaintained and broken.

[184] Beginning in 1993, he spent eighteen months of part-time development before he released the software on the Internet in February 1995.

In this first phase, rendering was done indirectly in the display server, leaving some overhead and noticeable speed lagging behind the theoretical maximum.

Video games outsource rendering calculations to the GPU over OpenGL in real-time. Shaders are written in OpenGL Shading Language or SPIR-V and compiled on the CPU. The compiled programs are executed on the GPU.
Illustration of the Linux graphics stack: DRM & libDRM, Mesa 3D . Display server belongs to the windowing system and is not necessary e.g. for gaming.
The free implementations of Wayland rely upon the Mesa implementation of EGL . The special library called libwayland-EGL , written to accommodate access to the framebuffer , should have been made obsolete by the EGL 1.5 release. On the GDC 2014 , AMD was exploring a strategy change towards using DRM instead of their in-kernel blob. [ 4 ]
Graphics device drivers are implemented using two components: a UMD (user-mode driver) and a KMD (kernel-mode driver). Starting with Linux kernel 4.2 AMD Catalyst and Mesa will share the same Linux kernel driver: amdgpu . Amdgpu provides interfaces defined by DRM and KMS.
A graphics driver consists of an implementation of the OpenGL state machine and a compilation stack to compile the shaders into the GPU's machine language. This compilation, as well as pretty much anything else, is executed on the CPU, then the compiled shaders are sent to the GPU and are executed by it. (SDL = Simple DirectMedia Layer ).
The Intermediate Representations (IRs) in Mesa: GLSL IR, Mesa IR, TGSI , and LLVM IR . Missing are HIR, LIR and NIR.
Mesa IR is due to be removed completely.
VC4 and freedreno can both consume NIR directly (and fall back to tgsi_to_nir for shaders that do not use glsl_to_nir).
Illustration of the Linux graphics stack
Mesa/ DRI and Gallium3D have different driver models. Both share a lot of free and open-source code.
A possible example matrix when implementing the Gallium3D driver model. Through the introduction of the Gallium3D Tracker Interface and the Gallium3D WinSys Interface, only 18 instead of 36 modules are required. Each WinSys module can work with each Gallium3D device driver module and with each State Tracker module.
GlassyMesa is an LLVM-based compiler stack for shaders written in GLSL . For SSA see the article Static single assignment form .