debian man page for cross_product

cross_product(3alleg4)						  Allegro manual					    cross_product(3alleg4)

NAME
       cross_product, cross_product_f - Calculates the cross product. Allegro game programming library.

SYNOPSIS
       #include <allegro.h>

       void cross_product(fixed x1, y1, z1, x2, y2, z2, *xout, *yout, *zout);

       void cross_product_f(float x1, y1, z1, x2, y2, z2, *xout, *yout, *zout);

DESCRIPTION
       Calculates  the	cross product (x1, y1, z1) x (x2, y2, z2), storing the result in (*xout, *yout, *zout). The cross product is perpendicular
       to both of the input vectors, so it can be used to generate polygon normals.

SEE ALSO
       dot_product(3alleg4), polygon_z_normal(3alleg4), normalize_vector(3alleg4), exstars(3alleg4)

Allegro 							   version 4.4.2					    cross_product(3alleg4)