just-gl

Run an OpenGL application on Linux, and nothing more.

Terminology

• DRI - Direct Rendering Infrastructure
• KMS - Kernel Mode Setting
• DRM - Direct Rendering Manager
• GBM - Generic Buffer Management
• EGL - An interface between OpenGL and the underlying native platform windowing system. Unlike predecessors GLX (for X11) and WGL (Windows), EGL is independent of the underlying display technology. It can be used on any number of platforms, including Wayland, X11, and KMS
• CRT - Cathode Ray Tube
• CRTC - CRT Controller, or Video Controller. Corresponds to a video buffer on a video card that is destined to be output

Kernel Setup for Nvidia Cards

I had to add nvidia_drm.modeset=1 as a kernel commandline parameter. On Arch this was done by editing /boot/loader/entries/arch.conf.

Reading References

https://gitlab.freedesktop.org/mesa/kmscube

https://github.com/dvdhrm/docs/tree/master/drm-howto

https://zamundaaa.github.io/wayland/2023/03/10/porting-away-from-gbm-surface.html

https://github.com/nyorain/kms-vulkan#what-are-egl-and-gbm

https://github.com/CuarzoSoftware/SRM

rust-windowing/winit#2272

Remote Environment Setup

Development can take place much faster if you develop in your local environment, and run/test on a remote machine without X11 or Wayland.

It's also necessary if you're developing on a non-linux platform, as libdrm and others are highly linux-specific.

I (bschwind) am currently using Sublime Text with this remote setup:

• Install the Rsync SSH Package
• Install rsync on both your local machine and the target remote machine
• Configure the Rsync SSH sublime package with your target machine's hostname, repo location, etc. My config looks like this:

Sublime RSync SSH Config

{
	"folders":
	[
		{
			"path": "/Users/brian/projects/tonari/just-gl",
		}
	],
	"settings":
	{
		"rsync_ssh":
		{
			"excludes":
			[
				".git*",
				"_build",
				"blib",
				"Build"
			],
			"options":
			[
				"--delete"
			],
			"remotes":
			{
				"/Users/brian/projects/tonari/just-gl":
				[
					{
						"command": "rsync",
						"enabled": 1,
						"excludes":
						[
						],
						"options":
						[
						],
						"remote_host": "tonarchi-test-machine.tonari.wg",
						"remote_path": "/home/tonari/projects/just-gl",
						"remote_port": 22,
						"remote_post_command": "",
						"remote_pre_command": "",
						"remote_user": "tonari"
					}
				]
			},
			"sync_on_save": true
		}
	},
}

• I have a passwordless SSH key to use to SSH into the target remote machine
• The target remote machine has my public SSH key added to ~/.ssh/authorized_keys
• On the remote machine, I use cargo watch (cargo install cargo-watch) to run a command which will execute every time files change on the file system (which happens every time you save files on your local machine, thanks to rsync):
  • $ cargo watch -x 'clippy --all-targets -- -D warnings'
• Develop locally, and receive compilation results from an SSH session on the remote machine (running cargo watch)