Install libsdl-gfx1.2-doc by entering the following commands in the terminal:
sudo apt update sudo apt install libsdl-gfx1.2-doc
Description:
documentation files for SDL_gfx
The SDL_gfx library is an extension to the SDL library which provides basic antialiased drawing routines such as lines, circles or polygons, an interpolating rotozoomer for SDL surfaces, framerate control and MMX image filters. . This package contains the documentation to program with the SDL_gfx library.
Homepage: http://www.ferzkopp.net/Software/SDL_gfx-2.0/
Version: 2.0.25-9
Section: universe/doc