void
lib3ds_track_eval_quat(Lib3dsTrack *track, float q[4], float t) {
lib3ds_quat_identity(q);
if (track) {
Lib3dsKey pp, p0, p1, pn;
float u;
int index;
float ap[4], bp[4], an[4], bn[4];
assert(track->type == LIB3DS_TRACK_QUAT);
if (!track->nkeys) {
return;
}
index = find_index(track, t, &u);
if (index < 0) {
lib3ds_quat_axis_angle(q, track->keys[0].value, track->keys[0].value[3]);
return;
}
if (index >= track->nkeys) {
quat_for_index(track, track->nkeys - 1, q);
return;
}
setup_segment(track, index, &pp, &p0, &p1, &pn);
rot_key_setup(pp.frame>=0? &pp : NULL, &p0, &p1, ap, bp);
rot_key_setup(&p0, &p1, pn.frame>=0? &pn : NULL, an, bn);
lib3ds_quat_squad(q, p0.value, ap, bn, p1.value, u);
}
}
/*!
* \ingroup tracks
*/
void
lib3ds_quat_track_eval(Lib3dsQuatTrack *track, Lib3dsQuat q, Lib3dsFloat t)
{
Lib3dsQuatKey *k;
Lib3dsFloat nt;
Lib3dsFloat u;
if (!track->keyL) {
lib3ds_quat_identity(q);
return;
}
if (!track->keyL->next) {
lib3ds_quat_copy(q, track->keyL->q);
return;
}
for (k=track->keyL; k->next!=0; k=k->next) {
if ((t>=k->tcb.frame) && (t<k->next->tcb.frame)) {
break;
}
}
if (!k->next) {
if (track->flags&LIB3DS_REPEAT) {
nt=(Lib3dsFloat)fmod(t, k->tcb.frame);
for (k=track->keyL; k->next!=0; k=k->next) {
if ((nt>=k->tcb.frame) && (nt<k->next->tcb.frame)) {
break;
}
}
ASSERT(k->next);
}
else {
lib3ds_quat_copy(q, k->q);
return;
}
}
else {
nt=t;
}
u=nt - k->tcb.frame;
u/=(k->next->tcb.frame - k->tcb.frame);
lib3ds_quat_squad(
q,
k->q,
k->dd,
k->next->ds,
k->next->q,
u
);
}
