quat_interpolate - Man Page

#include <allegro.h>

void quat_interpolate(const QUAT *from, const QUAT *to, float t, QUAT *out);

Constructs a quaternion that represents a rotation between from and to.  The argument t can be anything between 0 and 1 and represents where  between from and to the result will be. 0 returns from, 1 returns to, and  0.5 will return a rotation exactly in between. The result is copied to  out. This function will create the short rotation (less than 180 degrees)  between from and to.

exquat(3)

exquat(3).