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

       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.

Allegro                                           version 4.4.3                          matrix_to_quat(3alleg4)

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

#include<allegro.h>voidmatrix_to_quat(constMATRIX_f*m,QUAT*q);