Provided by: allegro5-doc_5.0.11-2_all 

NAME
al_fixhypot - Allegro 5 API
SYNOPSIS
#include <allegro5/allegro.h>
al_fixed al_fixhypot(al_fixed x, al_fixed y)
DESCRIPTION
Fixed point hypotenuse (returns the square root of x*x + y*y). This should be better than calculating
the formula yourself manually, since the error is much smaller.
al_fixhypot(3alleg5) Allegro reference manual()