/**
* Interpolate {@link #frame()} at time {@code time} (expressed in seconds). {@link
* #interpolationTime()} is set to {@code time} and {@link #frame()} is set accordingly.
*
* <p>If you simply want to change {@link #interpolationTime()} but not the {@link #frame()}
* state, use {@link #setInterpolationTime(float)} instead.
*/
public void interpolateAtTime(float time) {
this.checkValidity();
setInterpolationTime(time);
if ((keyFrameList.isEmpty()) || (frame() == null)) return;
if (!valuesAreValid) updateModifiedFrameValues();
updateCurrentKeyFrameForTime(time);
if (!splineCacheIsValid) updateSplineCache();
float alpha;
float dt =
keyFrameList.get(currentFrame2.nextIndex()).time()
- keyFrameList.get(currentFrame1.nextIndex()).time();
if (Util.zero(dt)) alpha = 0.0f;
else alpha = (time - keyFrameList.get(currentFrame1.nextIndex()).time()) / dt;
Vec pos =
Vec.add(
keyFrameList.get(currentFrame1.nextIndex()).position(),
Vec.multiply(
Vec.add(
keyFrameList.get(currentFrame1.nextIndex()).tgP(),
Vec.multiply(Vec.add(pv1, Vec.multiply(pv2, alpha)), alpha)),
alpha));
float mag =
Util.lerp(
keyFrameList.get(currentFrame1.nextIndex()).magnitude(),
keyFrameList.get(currentFrame2.nextIndex()).magnitude(),
alpha);
Rotation q;
if (gScene.is3D()) {
q =
Quat.squad(
(Quat) keyFrameList.get(currentFrame1.nextIndex()).orientation(),
((KeyFrame3D) keyFrameList.get(currentFrame1.nextIndex())).tgQ(),
((KeyFrame3D) keyFrameList.get(currentFrame2.nextIndex())).tgQ(),
(Quat) keyFrameList.get(currentFrame2.nextIndex()).orientation(),
alpha);
} else {
q =
new Rot(
Util.lerp(
keyFrameList.get(currentFrame1.nextIndex()).orientation().angle(),
keyFrameList.get(currentFrame2.nextIndex()).orientation().angle(),
(alpha)));
}
frame().setPositionWithConstraint(pos);
frame().setRotationWithConstraint(q);
frame().setMagnitude(mag);
}
/**
* Appends a new keyFrame to the path, with its associated {@code time} (in seconds).
*
* <p>When {@code setRef} is {@code false} the keyFrame is added by value, meaning that the path
* will use the current {@code frame} state.
*
* <p>When {@code setRef} is {@code true} the keyFrame is given as a reference to a Frame, which
* will be connected to the KeyFrameInterpolator: when {@code frame} is modified, the
* KeyFrameInterpolator path is updated accordingly. This allows for dynamic paths, where keyFrame
* can be edited, even during the interpolation. {@code null} frame references are silently
* ignored. The {@link #keyFrameTime(int)} has to be monotonously increasing over keyFrames.
*/
public void addKeyFrame(GenericFrame frame, float time) {
if (frame == null) return;
if (keyFrameList.isEmpty()) interpolationTm = time;
if ((!keyFrameList.isEmpty()) && (keyFrameList.get(keyFrameList.size() - 1).time() > time))
System.out.println("Error in KeyFrameInterpolator.addKeyFrame: time is not monotone");
else {
if (gScene.is3D()) keyFrameList.add(new KeyFrame3D(frame, time));
else keyFrameList.add(new KeyFrame2D(frame, time));
}
valuesAreValid = false;
pathIsValid = false;
currentFrmValid = false;
resetInterpolation();
}
/** Intenal use. Call {@link #checkValidity()} and if path is not valid recomputes it. */
protected void updatePath() {
checkValidity();
if (!pathIsValid) {
path.clear();
int nbSteps = 30;
if (keyFrameList.isEmpty()) return;
if (!valuesAreValid) updateModifiedFrameValues();
if (keyFrameList.get(0) == keyFrameList.get(keyFrameList.size() - 1))
// TODO experimenting really
path.add(
new Frame(
keyFrameList.get(0).position(),
keyFrameList.get(0).orientation(),
keyFrameList.get(0).magnitude()));
else {
KeyFrame[] kf = new KeyFrame[4];
kf[0] = keyFrameList.get(0);
kf[1] = kf[0];
int index = 1;
kf[2] = (index < keyFrameList.size()) ? keyFrameList.get(index) : null;
index++;
kf[3] = (index < keyFrameList.size()) ? keyFrameList.get(index) : null;
while (kf[2] != null) {
Vec pdiff = Vec.subtract(kf[2].position(), kf[1].position());
Vec pvec1 = Vec.add(Vec.multiply(pdiff, 3.0f), Vec.multiply(kf[1].tgP(), (-2.0f)));
pvec1 = Vec.subtract(pvec1, kf[2].tgP());
Vec pvec2 = Vec.add(Vec.multiply(pdiff, (-2.0f)), kf[1].tgP());
pvec2 = Vec.add(pvec2, kf[2].tgP());
for (int step = 0; step < nbSteps; ++step) {
Frame frame = new Frame();
float alpha = step / (float) nbSteps;
frame.setPosition(
Vec.add(
kf[1].position(),
Vec.multiply(
Vec.add(
kf[1].tgP(),
Vec.multiply(Vec.add(pvec1, Vec.multiply(pvec2, alpha)), alpha)),
alpha)));
if (gScene.is3D()) {
frame.setOrientation(
Quat.squad(
(Quat) kf[1].orientation(),
((KeyFrame3D) kf[1]).tgQ(),
((KeyFrame3D) kf[2]).tgQ(),
(Quat) kf[2].orientation(),
alpha));
} else {
// linear interpolation
float start = kf[1].orientation().angle();
float stop = kf[2].orientation().angle();
frame.setOrientation(new Rot(start + (stop - start) * alpha));
}
frame.setMagnitude(Util.lerp(kf[1].magnitude(), kf[2].magnitude(), alpha));
path.add(frame.get());
}
// Shift
kf[0] = kf[1];
kf[1] = kf[2];
kf[2] = kf[3];
index++;
kf[3] = (index < keyFrameList.size()) ? keyFrameList.get(index) : null;
}
// Add last KeyFrame
path.add(new Frame(kf[1].position(), kf[1].orientation(), kf[1].magnitude()));
}
pathIsValid = true;
}
}