fui, standing for framebuffer user interface, is a C library for interacting with the framebuffer in a tty context. It writes directly to the framebuffer device, using a system of layers for drawing. Some stuff that it does:

• Draws pixel values to an arbitrary number of layers, which are then composited together and rendered to the framebuffer.
• Primitive drawing functions for lines, rectangles, and circles.
• Text rendering using a bitmap font.
• Event handling for keyboard and mouse input (using libevdev), with a more generic event system implemented that can be used for other events.
• A cheeky sound system using alsa that can play sine tones and chords for now.

The actual library is in fui, and can be compiled and installed with:

make
sudo make install

The library can then be used by including -Lfui -l:libfui.a in your compiler flags. The library is statically linked, so you don't need to worry about shared libraries.

Since both the video and input access needs root privileges, it is recommended to add the user to these groups, to avoid running any compiled program with sudo. You can do this with:

sudo usermod -aG video "$USER"
sudo usermod -aG input "$USER"

You'll need to logout and log back in after this. If that doesn't work, a reboot should do it.

There are some (half-baked for now) examples included, in the examples folder. main.c and bodies.c kind of demonstrates most of the components of the library. In the asteroids folder we have a simple asteroids game, which uses the sound system. Also, in tests, there are a few tests implemented using cmocka.

Some stuff running with fui (from main.c).

Asteroids!