Godot 4.0 Support

[FrobtheBuilder]

I'd like to use this in a Godot 4.0 project and I think I see how you'd go about upgrading it to work. It looks like the only incompatibility is with the exports and setter/getter syntax. However, I'm still pretty new to the engine so I'm not sure if the shader is going to implode or something if I fix the script, and also I think they changed some stuff about how viewports work. Fixing that would probably be beyond me, plus I'm not sure if this library will do exactly what I want in the first place... I'm looking for a method of getting decent antialiased pixel art upscaling to non-integer screen resolutions for a 2D game.

1. Do you think the shader is still compatible with the new Vulkan backend? I saw a few of these warnings in the editor, but no errors.
   
2. Would you rather just do the porting yourself, or would you accept a PR from me if I fixed the script?
3. Can this library actually do what I'm looking for? It looks to me like it should be able to, but I'm not certain.

[cybereality]

I did actually port it to Godot 4.0, but I never released it. This is because Godot 4.0 has built-in scaling options that are better than this. If you enable the Advanced Options in the Project Settings, there is a mode for Scaling 3D. This uses either Bilinear Interpolation or AMD FSR. I am not sure if it works for 2D, maybe not. But I did some testing, and these options were better than my shader in terms of the quality and performance. So I opted not to release the code, since it wouldn't be useful. If you want to use this for 2D, I can clean up the port and post the code, it wouldn't be that much work. I just didn't think anyone would use it.

[FrobtheBuilder]

Yeah the crazy thing is I actually tried using the various antialiasing options in the settings, but no dice. MSAA doesn't work on textures and FXAA seems to apply AFTER upscaling, so I still get oddly shaped pixels everywhere. Aaaaand... I just checked and sadly the 3D scaling options don't apply at all to 2D viewports. This is making me sad. What I need is to scale up to an integer and then scale back down with antialiasing. Would you mind sharing the port so I can give it a try? I've got a slightly unusual use case here, I need to accommodate flip screen on one dimension so I don't want to zoom the camera too much for different resolutions.

[cybereality]

So my add-on doesn't do integer scaling. I was going to add it originally, but I didn't get much interest, so I stopped working on it. Also, since I mainly work in 3D, I didn't need it for anything I was doing. But I know how to do it. Just give me like a day or two to take a look at the code, it's shouldn't be too difficult.

[FrobtheBuilder]

Oh thanks, that would be very helpful. I've been playing around with other camera systems in the meantime but even fully dynamic the size of the viewport I want just doesn't quite line up with the closest integer scales at 1080p, to say nothing of other resolutions. Being able to scale arbitrarily with antialiasing would help me out a lot, but I'm just not quite sure how to make it happen myself.