Raspberry Pi 2 - Distortion while moving objects in Portrait mode

Question

I am currently working on a Kiosk system based on the Raspberry Pi 2 running Raspbian which runs a Java app. Everything works perfectly well, except for a distortion on the screen which appears while objects are moving. Normally, this wouldn't be a problem, but I have a list on the Java app which will be extensively used by the users. The distortion is visible while scrolling on this list.

The link below shows this in action:

A GIF showing the distortion

What I know so far:

• This only occurs while the screen is rotated. I have rotated the screen by 270* by setting “display_rotate=3” in /boot/config.txt
• It is not dependent on the screen resolution or the “hdmi_group"
• This doesn't happen only on the GUI, the distortion is also visible during boot time
• Overlocking doesn't affect the distortion
• It always appearson the right-bottom side of the screen
• This issue was also present in Ubuntu Mate

Answer 1

I'm not a specialist in Linux or anything like that but hear me out,

You say that you rotate your screen in the config file. Could you put it back to the default? Why do you need it to be rotated? Because this rotation could cause it to off align parts of the screen. I would first for your problem look at experimenting with that variable and see how it changes. :)

Answer 2

Look at this: https://github.com/justincjack/rasp_pi_graphics

It's a library that I wrote that will definitely solve your issue. It will create a shared object (and static) with a C header file. If you can create Java bindings for it to be able to use the lib it produces your problems will be over.

I couldn't find any info that really worked, so this is the product of a few weeks worth of work.

It allows smooth rendering with no tearing and no crazy deep-digging into libdri (libdrm)/kms.

Answer 3

Based on the information provided, it appears that the distortion is caused by an issue with the display hardware or driver.

It is possible that the GPU or display driver is not correctly configured to handle the rotation of the display or that the display hardware cannot control the rotation. To troubleshoot this issue, you could try the following steps:

1. Try different display resolutions and settings in /boot/config.txt to see if the distortion is affected.
2. Try a different display driver, such as the open-source driver from the Raspberry Pi Foundation.
3. Try a different display, such as a different monitor or television.
4. Try a different operating system, such as Raspbian or Ubuntu.
5. Check the display hardware for any signs of damage or wear.

If these steps do not resolve the issue, then it is likely that the display hardware is not compatible with the rotation of the display. In this case, you may need to purchase a different display or use a different rotation setting.