Difference between Flutter_wayland and flutter-pi

[limbouser]

Apart from the fact that one is designed for Pi and other for a 64bit machine, what is the difference between flutter_wayland and flutter-pi?

Does flutter-pi run on a machine if vc4graphics isn't available?

[ardera]

The difference is basically an additional layer of abstraction. For flutter_wayland, it looks like this:
DRM (linux kernel) <-- wayland <-- flutter_wayland <-- flutter

For flutter-pi, it looks like this:
DRM (linux kernel) <-- flutter-pi <-- flutter

So, basically, for flutter_wayland, there's an additional layer between the linux kernel and flutter_wayland, while flutter-pi communicates with the linux kernel directly.

There's some advantages to this (flutter-pi's) approach, but also some drawbacks.

Advantages:

• resources. It's just plain wasteful to start a whole wayland server for a single, full-screen application.
• faster (in general, and also startup) because of less overhead.
• easier to implement platform-specific stuff. For example, in the past, the Raspberry Pi used a different graphics stack. IIRC, you could only get hardware acceleration for OpenGL by using that proprietary graphics stack. If you want to make flutter-pi compatible with some platform that still uses such a non-standard grahpics stack, you could just modify the init_graphics procedure of flutter-pi to get it to work. It's not that easy with flutter_wayland though, as you'd have to update wayland for that.

Disadvantages:

• wayland does a lot of stuff other than graphics. flutter_pi has to implement that stuff by itself. For example, there's no way to just change the speed of your mouse for flutter-pi, because there's no layer of abstraction in flutter-pi that'd implement such configuration. Keyboard layouts is similiar, that's why there's this limitation to the text input from the controlling console (see readme).
• you can't run flutter-pi alongside your x- or wayland-server.

Does flutter-pi run on a machine if vc4graphics isn't available?

flutter-pi uses the standard linux graphics stack. So if hardware acceleration of your machine works with the standard linux graphics stack, it should run. If it uses a different graphics stack, you'd need to apply some hacks.

[limbouser]

Doesn't Wayland alone exist? Can I run flutter-pi somewhere if I can't afford to have vc4-drm? What changes wouldnI have to make to make this thing work on plain Wayland?

[ardera]

Doesn't Wayland alone exist?

I don't understand what you mean by this.

Can I run flutter-pi somewhere if I can't afford to have vc4-drm?

As I wrote above, if it has working DRM support, flutter-pi should run. That's untested though. I don't understand what you mean by "afford to have vc4-drm".

What changes wouldnI have to make to make this thing work on plain Wayland?

The sole purpose of flutter-pi is to run without X or wayland, so you could probably discard most of the flutter-pi.c, console_keyboard.c files. No idea what specific changes would be necessary though.