Install libsdl2-gfx-doc by entering the following commands in the terminal:
sudo apt update sudo apt install libsdl2-gfx-doc
Description:
documentation files for SDL2_gfx
The SDL2_gfx library is an extension to the SDL2 library which provides basic antialiased drawing routines such as lines, circles or polygons, an interpolating rotozoomer for SDL2 surfaces, framerate control and MMX image filters. . This package contains the documentation to program with the SDL2_gfx library.
Homepage: https://www.ferzkopp.net/joomla/content/view/19/14/
Version: 1.0.4+dfsg-1
Section: universe/doc