Back with Org Mode

If there is one thing I’d like to commit it must be the my time mangement improvements. For that purpose, Emacs Org-mode is the ultimate tool for programmers. I can keep my notes nicely and I can track my tasks/errands all together. But all my notes are stored in my linux box, I lose access to them once I am away. From that reason, I was always on-and-off with using org-mode due to the portability.

Xwayland Clipboard

I hate every single line of xwayland code I wrote, it is ugly, long and hard to maintain. Now I know very well why there is wayland in the first place, sadly a complete wayland compositor has to bring a piece of crap of X with it. I just finished the selection handling in xwayland by mimicing weston code. After finally understand that 1000 lines of confusing code, I just found out I can’t do any better.

Jan 2021 Status Update

Folks, the Magical year of 2020 is behind us, and it wasn’t a happy new chapter waiting us. Man, I still couldn’t believe, once per 100 years, why it was us who have to face the coronavirus. Now I take a good look of my 2020, I went from trying to submit a xcbcommon handling patch to weston to writing a full wayland compositor from scratch. It was not my plan!

Working with libdrm, buffer allocation

In the first blog of libdrm, we went through the repainting loop using the libdrm. Now we move on to the topic of framebuffers. A framebuffer is a piece of memory (could be on main memory or on GPU) for repainting every frame. It is like a canvas, represents what you would finally see on screen. Framebuffer is already a familiar concept to rendering programmers, in OpenGL, We have GL_FRAMEBUFFER_0 for presenting the surface, additional framebuffers for roles like G-Buffer and post-processing.

Working with libdrm, repainting timeline

As the taiwins project finished with X11/Wayland backend rigging. Now I am fully on the libdrm backend development, dealing with hardwares directly. This backend requires 200 percent my energy to tame the complexity. Like other backends, libdrm also needs to provide two resources, input and output. Backends like nested wayland backend or X11 backend, the output device are the windows created by ourselves (or by the user). Meaning we can create it or destroy it as we please.

August 2020 Status Update

It is a sunny day, somehow I got up early this morning. The cool, chilling breath of air reminded me we are at the tail of the summer. It felt so strange, this summer was like it was never here. Hiking, go swimming, taking a trips and night outs. all those experiences for a normal summer I would do, they are all absent, hope I don’t regret too much for crunching code at home all these months.

July 2020 Status Update

July, the hottest month in Montreal every year. The heat wave rushes to you when you walk outside makes you wondering if you are in some tropical island, it sure doesn’t look like living at 45 latitde northen hemisphere. Last month was a rapid leap towards wayland objects implementations and now I just hitted the wall of xdg-shell protocol. Today I’d like to talk about what it is like to implement a wayland protocol.

June 2020 Status Update

Montréal is hotter than ever in this month, under the broiling sun, it was an exhausting quarantine. The first month I remeber I was feeling fortunate I got this aleatory chance for advancement of taiwins in this global pandemic, right now all I felt was the painful experience converting all the Taiwins server code away from libweston. Implementating of server side wayland objects was indeed unpleasant experience. Without libweston, I have to implement every little thing and get it right, even the basics 2D homogenous matrix operations for coordinates transformations.

Libweston vs Wlroots

You need a wayland compositor library to create a wayland server. Wayland is a protocol, itself, cannot do much, long time ago I used to think the server-side wl_resource represents some structure you can operate on, well it turned out all you do with it is handling messages between client and server. All the logic you need to implement yourself. There were a few attempts to wayland compositing library created. The first sucessful one is wlc.


wl_data_device interface in the base wayland protocol is the most complex one, in my opinion, wayland.xml explains it fairly well, but every pieces are scattered in the file, here I serialize it together, give you quick run through. In brief, data device in wayland consists of four interfaces: The first is wl_data_device_manager, it is the global. The second is wl_data_device, can be created from wl_data_device_manager for a given seat, it is used to set selection(ctrl-c ctrl-v) and drag-n-drop.