The SDL_gfx library evolved out of the SDL_gfxPrimitives code which
provided basic drawing routines such as lines, circles or polygons and
SDL_rotozoom which implemented a interpolating rotozoomer for SDL
surfaces. The current components of the SDL_gfx library are:

- Graphic Primitives (SDL_gfxPrimitives.h)

- Rotozoomer (SDL_rotozoom.h)

- Framerate control (SDL_framerate.h)

- MMX image filters (SDL_imageFilter.h)

The library is backwards compatible to the above mentioned code. It is
written in plain C and can be used in C++ code.