matrix_to_quat - Man Page

Constructs a quaternion from a rotation matrix. Allegro game programming library.

Synopsis

#include <allegro.h>

void matrix_to_quat(const MATRIX_f *m, QUAT *q);

Description

Constructs a quaternion from a rotation matrix. Translation is discarded  during the conversion. Use get_align_matrix_f() if the matrix is not  orthonormalized, because strange things may happen otherwise.

Info

version 4.4.3 Allegro manual