quat_slerp (3) - Linux Manuals
quat_slerp: Version of quat_interpolate() allowing control over the rotation. Allegro game programming library.
NAME
quat_slerp - Version of quat_interpolate() allowing control over the rotation. Allegro game programming library.SYNOPSIS
#include <allegro.h>
void quat_slerp(const QUAT *from, const QUAT *to, float t, QUAT *out, int how);
DESCRIPTION
The same as quat_interpolate(), but allows more control over how the rotation is done. The how parameter can be any one of the values:
QUAT_SHORT - like quat_interpolate(), use shortest path QUAT_LONG - rotation will be greater than 180 degrees QUAT_CW - rotate clockwise when viewed from above QUAT_CCW - rotate counterclockwise when viewed from above QUAT_USER - the quaternions are interpolated exactly as given