cross_product, cross_product_f - Calculates the cross product. Allegro game
programming library.
#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);
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.
dot_product(3), polygon_z_normal(3), normalize_vector(3),
exstars(3)