Allegro?
SDL?
OpenGL?

I'm going to buy a book on SDL, but before I do that, should I use OGL or allegro?

Allegro and OpenGl are different category.

"Allegro is a cross-platform library intended for use in computer games and other types of multimedia programming." --Allegro sourceforge site.

"Simple DirectMedia Layer is a cross-platform multimedia library designed to provide low level access to audio, keyboard, mouse, joystick, 3D hardware via OpenGL, and 2D video framebuffer." --libsdl.org

"OpenGL (for “Open Graphics Library”) is a software interface to graphics hardware. The interface consists of a set of several hundred procedures and functions that allow a programmer to specify the objects and operations involved in producing high-quality graphical images, specifically color images of three-dimensional objects." --OpenGL 2.1 Spec.


Use them for what purpose? Since you fail to tell us anything meaningful about your purpose for using any of the 3, how could anyone here provide anything more than a completely subjective response to "Which API is the best?"


MxB