Texpainter is a utility program intended for creating tilable textures. It consists of very basic raster graphics editor (more basic than Ms Paint, though it supports transparency), combined with a powerful node based compositor, through which multiple images can be processed and combined to a single image.
Install
If you do not have it, also install g++ version 10 or later, since the code uses some new features from C++20.
Install maike, and wad64, currently avaiable in the ppa:s https://launchpad.net/~milasudril/+archive/ubuntu/maike and https://launchpad.net/~milasudril/+archive/ubuntu/wad64 That is,
sudo add-apt-repository ppa:milasudril/maike
sudo add-apt-repository ppa:milasudril/wad64
sudo apt-get update
sudo apt-get install maike wad64
Should do the trick
Run make
The binary can now be started with the command __targets_rel/app/texpainter