Graphical artifacts on OnePlus 6 phone

Issue details

On OnePlus 6 phones, and possibly other models, there are graphical artifacts similar to low quality JPEG compression in images. It is especially obvious if there are large single colored areas. It is not equally obvious with all colors, and I have found that the color #2c2c2c reveals the issue well.

Interestingly, the artifact does not show up in screenshots, so I have tried to photograph it using another phone. It is barely visible in the photos, but on the screen of the OnePlus phone they are clearly obvious. I have marked where the issue occurs, you can (barely) see lines across the screen.

https://i.imgur.com/E8rccLa.png https://i.imgur.com/ONtum3B.png

In the test project there are lines, but in my app they are more like cubes like in badly compressed JPEG images.

The phone runs on Android 10. I have also tried on the Pixel emulator with Android 10 and Google services and have not been able to reproduce it on that. On a Sony XZ1, Samsung S5, Nexus 5, Honor 7 as well as the desktop version it runs fine.

Now I guess if none of you have a OnePlus 6 it will be hard to debug this. If someone would give me an idea of where to begin to look that would be greatly appreciated.

Reproduction steps/code

1. Generate a blank LibGDX project
2. Replace the code of the main ApplicationAdapter with this:

public class MyGdxGame extends ApplicationAdapter {
	SpriteBatch batch;
	Color bgColor;
	
	@Override
	public void create () {
		batch = new SpriteBatch();
		bgColor = Color.valueOf("2c2c2c");
	}

	@Override
	public void render () {
		Gdx.gl.glClearColor(bgColor.r, bgColor.g, bgColor.b, bgColor.a);
		Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);
	}
	
	@Override
	public void dispose () {
		batch.dispose();
	}
}

1. Run on a OnePlus 6
2. If the issue does not occur, try exiting and entering the app a couple of times. Maybe also kill and restart it.

Version of LibGDX and/or relevant dependencies

gdxVersion = ‘1.9.10’

Please select the affected platforms

• Android
• iOS (robovm)
• iOS (MOE)
• HTML/GWT
• Windows
• Linux
• MacOS

[crykn]

This stackoverflow post seems to suggest that RGB565 was the default for GLSurfaceView. However, that doesn’t seem to be the case anymore:

If no setEGLConfigChooser method is called, then by default the view will choose an RGB_888 surface with a depth buffer depth of at least 16 bits.

[MobiDevelop]

I think it is odd that we still use RGB565 by default.