docs: graphic driver

NixOS.md

@@ -414,6 +414,56 @@ nix-shell -p appimage-run
 appimage-run ~/Downloads/ubports-installer_0.10.0_linux_x86_64.AppImage
 ```
 
+## Graphic drivers
+
+Usually most of this should work out of the box on NixOS.
+
+Vulkan:
+- Verification: If `vulkaninfo` returns information about your GPU, Vulkan is working. https://wiki.archlinux.org/title/Vulkan#Verification
+
+OpenGL:
+- Verification: https://wiki.archlinux.org/title/OpenGL#Verification
+  - `eglinfo -B` should not return `eglInitialize failed`
+  - `eglgears_x11` and `eglgears_wayland` -> ![eglgears.png](assets/doc/eglgears.png)
+
+Video acceleration:
+- VA-API
+  - Verifying: `vainfo` -> E.g. `Driver version: Mesa Gallium driver 23.1.9 for AMD Radeon Graphics`. https://wiki.archlinux.org/title/Hardware_video_acceleration#Verifying_VA-API
+  - Driver comparison chart. https://wiki.archlinux.org/title/Hardware_video_acceleration#VA-API_drivers
+    - With `libva-mesa-driver` on "Radeon RX 7900 and higher/newer" a codec for encoding AV1 8 and 10 bit is available.
+- VDPAU
+  - Video Decode and Presentation API for Unix (VDPAU).
+  - Verifying: `vdpauinfo`. https://wiki.archlinux.org/title/Hardware_video_acceleration#Verifying_VDPAU
+
+Configuration example for an AMD GPU:
+
+```nix
+hardware.opengl = {
+  enable = true;
+  # Whether to enable accelerated OpenGL rendering through the Direct Rendering Interface (DRI).
+  # The Direct Rendering Infrastructure (DRI) is the framework comprising the modern Linux graphics [...]. The main use of DRI is to provide hardware acceleration for the Mesa implementation of OpenGL.
+  driSupport = true;
+  extraPackages = [
+    # AMD Open Source Driver For Vulkan
+    pkgs.amdvlk
+    
+    # Encoding/decoding acceleration
+    #
+    # VDPAU driver with OpenGL/VAAPI backend
+    pkgs.libvdpau-va-gl
+    # VDPAU driver for the VAAPI library
+    pkgs.vaapiVdpau
+    
+    # OpenCL (Open Computing Language) is a framework for writing programs that execute across heterogeneous platforms.
+    #
+    # OpenCL ICD definition for AMD GPUs using the ROCm stack.
+    pkgs.rocm-opencl-icd
+    # OpenCL runtime for AMD GPUs, part of the ROCm stack.
+    pkgs.rocm-opencl-runtime
+  ];
+};
+```
+
 ## Additional resources
 
 * Simple NixOS flake template for NixOS with HomeManager. https://github.com/Misterio77/nix-starter-configs#readme