Use SDL for joypad input on Linux

[EIREXE]

SDL is loaded in the same way other Linux system libraries are loaded by using a wrapped and dlopen.

Optionally, SDL can be dynamically linked into the binary.

Currently for Linux only since that platform direly needs it, but should be easy to make work on Windows once stable.

Proposal at: godotengine/godot-proposals#9000

P.S: I've made sure to strip the files as much as possible, but unless you want to be pulling your hair out by stripping files individually this is the best we can do IMO.

• Bugsquad edit, related to Switch to SDL as the main gamepad input driver godotengine/godot-proposals#9000 and Laptop touchpads are seen as gamepads godotengine/godot#59250

[sDIMMaX]

I think this is more than this proposal - my opinion switch to SDL in core as input and window manager.
Exist strong reasons why -
1: Codebase more easy to support, because maintainers of SDL know he work and do this very well. (check Godot issues in input system (ios, android, etc)) and we can avoid this just switching to SDL
2: Platforms - SDL have huge platforms support. I talk about consoles. Example - why on console X - this not working/have issue.

Maybe not now, but i think we can make discussion on this.

[brianhsu]

As a Linux user, I strongly second this. SDL is basically the de-facto standard when handling gamepad in Linux. And currently the Godot implementation is not that reliable. I don't remember how many times I had to restart Godot and pray it detect my gamepad while other games using SDL had no problem at all.

I don't mind if the executable file will increase a few megabytes, it's not big deal for me IMO.

[yarbelk]

Reviewing from a phone is headache inducing. I just looked the Python, which is about the maximum effort I could stomach in a phone

[yarbelk]

My read on sccon environments and a quick check of its usage in the project says that the falsy check is unneeded, so this could just be

But I'd like someone who actually uses sccon more than me to verify this

Suggested change

	if "sdl" in env and env["sdl"]:
	if "sdl" in env:

[yarbelk]

Are we changing references to Godot in new code?

[OldDev78]

There is a PR that updates the copyright disclaimer script. That probably should be executed by maintainers at some point. Also, this PR has been rescued from Godot purgatory, it seems.