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ALLEGRO_PI - Allegro 5 API

ALLEGRO_PI(3alleg5) ALLEGRO_PI(3alleg5)

NAME

ALLEGRO_PI - Allegro 5 API

SYNOPSIS

#include <allegro5/allegro.h>
#define ALLEGRO_PI        3.14159265358979323846

DESCRIPTION

C99 compilers have no predefined value like M_PI for the constant π, but you can use this one instead.
Allegro reference manual