glxinfo

glxinfo [options]

-display
    Specifies the X display to connect to. If not specified, uses the DISPLAY environment variable.

-t
    Print only a table of GLX visuals (format is similar to xdpyinfo).

-v
    Verbose output.

-b
    Print only basic GLX information.

-i
    Print only the direct rendering information. This is the same as using -v and then grep'ing for "direct rendering".

-h
    Display help text.

glxinfo is a command-line utility that provides detailed information about the OpenGL implementation running on an X Window System server. It queries the X server and the OpenGL client driver to gather data on various aspects, including: the OpenGL version, the supported extensions, the rendering context, and the visual configuration. This information is crucial for developers debugging OpenGL applications, verifying driver configurations, and ensuring compatibility across different systems. It allows users to assess if their hardware and software are correctly configured for OpenGL. It is especially helpful when troubleshooting graphics-related issues and identifying potential bottlenecks in rendering pipelines. Output includes details about the vendor, renderer, and version of OpenGL, as well as a long list of supported OpenGL extensions. Knowing which extensions are supported by your OpenGL implementation is very important for many programs to run correctly.

Note: It requires an X Window System to be running.

glxinfo requires an X server to be running and a GLX-capable OpenGL implementation to be installed. The output may vary depending on the graphics driver and hardware configuration. The direct rendering context might not be available if the X server isn't properly configured or if there's a mismatch between the driver and the hardware.

Direct rendering is a feature that allows OpenGL applications to render directly to the graphics card, bypassing the X server. This can significantly improve performance, especially for demanding applications like games and 3D modeling software. glxinfo is used to confirm that direct rendering is enabled, a crucial aspect for optimal OpenGL performance.

The extensive list of OpenGL extensions reported by glxinfo indicates the features supported by the OpenGL implementation. Applications may use these extensions to access advanced rendering techniques and hardware-specific capabilities.

glxinfo was developed as part of the X Window System and its OpenGL extension (GLX). It's been around since the early days of OpenGL adoption on Linux and other Unix-like systems. It serves as a crucial tool for diagnosing OpenGL configurations.

xdpyinfo(1), xrandr(1), opengl(7)