Add official Linux ARM/Raspberry Pi editor and export template binaries

[Schweini07]

Bugsquad edit: You can use https://github.com/hiulit/Unofficial-Godot-Engine-Raspberry-Pi until official builds are provided.

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The re-open of godotengine/godot#2671.

NOTE: This issue is more about Godot 3.2, as Godot 3.0.6 and 3.1 are possible to get on the pi, with the costs of a few bugs, for more information read below.

If you have anything to add, please tell me.

Takeaways:

• Godot 3 works on the Raspberry Pi 4 due to the support for GLES3
• A user named efornara got Godot 3.0.6/3.1 with GLES2 working on the Raspberry Pi 3 B+ trough compiling and other methods, see:
  Add official Raspberry Pi support godot#2671 (comment) (The error from compiling was apparently caused due to an upstream bug, see: Add official Raspberry Pi support godot#2671 (comment))
  Add official Raspberry Pi support godot#2671 (comment)
• There's a repo (https://github.com/efornara/frt) which let's the Pi support Godot 2.1/3.0/3.1 BUT not /3.2

Other interesting things I found:

• This website: http://raspbian.raspberrypi.org/raspbian/pool/main/g/godot/, which apparently has Godot 3.2 executables for the Pi
• On https://repology.org/project/godot/versions, there's also apparently Godot 3.2 listed as an official raspbian package, it's not marked Stable but as Testing.
• When you want to install Godot trough apt on the Pi you write apt install godot, Godot 3.0.6 gets installed, as it's apparently the stable package (see link above).
• Someone got export templates for Pi working on 2.1.4: https://github.com/crabcrabcam/godot/releases
• This post: https://www.reddit.com/r/godot/comments/af1cji/compiling_godot_31_for_raspberry_pi/, where someone made instructions, on how to compile Gdot 3.1.1 for the Pi

Describe the project you are working on:
Applies to any project made on a Pi.

Describe the problem or limitation you are having in your project:
It's hard perhaps even impossible, to get Godot 3.2 working on the Pi.

Describe the feature / enhancement and how it helps to overcome the problem or limitation:
It's hard to tell why Godot 3.2 doesn't work with Pis below 4. My assumption is that it has to do something with the missing GLES3 or because the Pi has an ARM processor (https://godotengine.org/qa/13114/export-godot-project-for-raspberry-pi). I think it could help to look into: https://github.com/efornara/frt

Describe how your proposal will work, with code, pseudocode, mockups, and/or diagrams:
As I don't know the exact problems, I can't tell.

If this enhancement will not be used often, can it be worked around with a few lines of script?:
A few lines of code probably won't do it, but Godot 3.2 is desired from Raspberry Pi users.

Is there a reason why this should be core and not an add-on in the asset library?:
It isn't possible.

[efornara]

As a clarification, FRT (export template) does support Godot 3.2. In fact, I have just noticed this proposal when publishing 3.2.2-beta4 (https://sourceforge.net/projects/frt/files/previews/). Godot 3.2.1-stable is still available (it is the default download).

The unmodified x11 platform of Godot 3.2 should work out of the box on a Pi 4 and, by changing the OpenGL system settings, on a Pi 2/3 too. You should add a compiler flag to select hard float when generating the binaries, and I think some people have problems when using GCC, but, apart from that, it should be fine.

[realkotob]

I've worked with godot 3.2 and 3.1 on the raspberry PI 3A and 3B+

It works pretty well for 2D.

However, even for 2D there are a lot of optimizations and graphical limitations that the user needs to do and figure out on their own.

I still think it would be useful to make an official RPI export template, and I would love to help to make it happen since it would be useful to a lot of users, but this can only happen after #877 is decided since RPI is considered a low-end platform.

Example limitations: Particles do not work at all, and there's a texture memory limit that means that it's better to load things as needed instead of loading everything into the scene at once (or else they will appear black ingame).

[antv199]

I found this Vulkan update for the Raspberry Pi. This might come in handy.

[Coolcreeper27]

This would help for beginning game devs to be able code any time

[Calinou]

@Coolcreeper27 Please don't bump issues without contributing significant new information. Use the 👍 reaction button on the first post instead.

[dh928]

I've worked with godot 3.2 and 3.1 on the raspberry PI 3A and 3B+

It works pretty well for 2D.

However, even for 2D there are a lot of optimizations and graphical limitations that the user needs to do and figure out on their own.

I still think it would be useful to make an official RPI export template, and I would love to help to make it happen since it would be useful to a lot of users, but this can only happen after #877 is decided since RPI is considered a low-end platform.

Example limitations: Particles do not work at all, and there's a texture memory limit that means that it's better to load things as needed instead of loading everything into the scene at once (or else they will appear black ingame).

How did you get it to work on your pi 3B+?

[realkotob]

@dh928 You can use the FRT thing directly or use this thing which makes it run within RetroPie.

Note that some things are not supported, like particle effects or Websockets (but fortunately I used the other TCP option for multiplayer, so wasn't an issue since I changed 1 line).

[ShalokShalom]

Would be nice to find it here 🥳