man identity_matrix () - Global containing the identity matrix. Allegro game programming library.
NAME
identity_matrix, identity_matrix_f - Global containing the identity matrix. Allegro game programming library.
SYNOPSIS
#include <allegro.h>
extern MATRIX identity_matrix;
extern MATRIX_f identity_matrix_f;
DESCRIPTION
Global variables containing the 'do nothing' identity matrix. Multiplying by the identity matrix has no effect.