/**
* 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);
}
protected void updateSplineCache() {
Vec deltaP =
Vec.subtract(
keyFrameList.get(currentFrame2.nextIndex()).position(),
keyFrameList.get(currentFrame1.nextIndex()).position());
pv1 =
Vec.add(
Vec.multiply(deltaP, 3.0f),
Vec.multiply(keyFrameList.get(currentFrame1.nextIndex()).tgP(), (-2.0f)));
pv1 = Vec.subtract(pv1, keyFrameList.get(currentFrame2.nextIndex()).tgP());
pv2 = Vec.add(Vec.multiply(deltaP, (-2.0f)), keyFrameList.get(currentFrame1.nextIndex()).tgP());
pv2 = Vec.add(pv2, keyFrameList.get(currentFrame2.nextIndex()).tgP());
splineCacheIsValid = true;
}
/**
* Starts the interpolation process.
*
* <p>A timer is started with an {@link #interpolationPeriod()} period that updates the {@link
* #frame()}'s position, orientation and magnitude. {@link #interpolationStarted()} will return
* {@code true} until {@link #stopInterpolation()} or {@link #toggleInterpolation()} is called.
*
* <p>If {@code period} is positive, it is set as the new {@link #interpolationPeriod()}. The
* previous {@link #interpolationPeriod()} is used otherwise (default).
*
* <p>If {@link #interpolationTime()} is larger than {@link #lastTime()}, {@link
* #interpolationTime()} is reset to {@link #firstTime()} before interpolation starts (and
* inversely for negative {@link #interpolationSpeed()}.
*
* <p>Use {@link #setInterpolationTime(float)} before calling this method to change the starting
* {@link #interpolationTime()}.
*
* <p><b>Attention:</b> The keyFrames must be defined (see {@link #addKeyFrame(GenericFrame,
* float)}) before you startInterpolation(), or else the interpolation will naturally immediately
* stop.
*/
public void startInterpolation(int myPeriod) {
if (myPeriod >= 0) setInterpolationPeriod(myPeriod);
if (!keyFrameList.isEmpty()) {
if ((interpolationSpeed() > 0.0)
&& (interpolationTime() >= keyFrameList.get(keyFrameList.size() - 1).time()))
setInterpolationTime(keyFrameList.get(0).time());
if ((interpolationSpeed() < 0.0) && (interpolationTime() <= keyFrameList.get(0).time()))
setInterpolationTime(keyFrameList.get(keyFrameList.size() - 1).time());
if (keyFrameList.size() > 1) interpolationTimerTask.run(interpolationPeriod());
interpolationStrt = true;
update();
}
}
/**
* Updates {@link #frame()} state according to current {@link #interpolationTime()}. Then adds
* {@link #interpolationPeriod()}* {@link #interpolationSpeed()} to {@link #interpolationTime()}.
*
* <p>This internal method is called by a timer when {@link #interpolationStarted()}. It can be
* used for debugging purpose. {@link #stopInterpolation()} is called when {@link
* #interpolationTime()} reaches {@link #firstTime()} or {@link #lastTime()}, unless {@link
* #loopInterpolation()} is {@code true}.
*/
protected void update() {
interpolateAtTime(interpolationTime());
interpolationTm += interpolationSpeed() * interpolationPeriod() / 1000.0f;
if (interpolationTime() > keyFrameList.get(keyFrameList.size() - 1).time()) {
if (loopInterpolation())
setInterpolationTime(
keyFrameList.get(0).time()
+ interpolationTm
- keyFrameList.get(keyFrameList.size() - 1).time());
else {
// Make sure last KeyFrame is reached and displayed
interpolateAtTime(keyFrameList.get(keyFrameList.size() - 1).time());
stopInterpolation();
}
} else if (interpolationTime() < keyFrameList.get(0).time()) {
if (loopInterpolation())
setInterpolationTime(
keyFrameList.get(keyFrameList.size() - 1).time()
- keyFrameList.get(0).time()
+ interpolationTm);
else {
// Make sure first KeyFrame is reached and displayed
interpolateAtTime(keyFrameList.get(0).time());
stopInterpolation();
}
}
}
/**
* Returns the Frame associated with the keyFrame at index {@code index}.
*
* <p>See also {@link #keyFrameTime(int)}. {@code index} has to be in the range 0..{@link
* #numberOfKeyFrames()}-1.
*
* <p><b>Note:</b> If this keyFrame was defined using a reference to a Frame (see {@link
* #addKeyFrame(GenericFrame, float)} the current referenced Frame state is returned.
*/
public GenericFrame keyFrame(int index) {
/**
* AbstractKeyFrame kf = keyFr.get(index); return new Frame(kf.orientation(), kf.position(),
* kf.magnitude());
*/
return keyFrameList.get(index).frame();
}
protected void updateModifiedFrameValues() {
KeyFrame kf;
KeyFrame prev = keyFrameList.get(0);
kf = keyFrameList.get(0);
int index = 1;
while (kf != null) {
KeyFrame next = (index < keyFrameList.size()) ? keyFrameList.get(index) : null;
index++;
if (next != null) kf.computeTangent(prev, next);
else kf.computeTangent(prev, kf);
prev = kf;
kf = next;
}
valuesAreValid = true;
}
/**
* Appends a new keyFrame to the path.
*
* <p>Same as {@link #addKeyFrame(GenericFrame, float)}, except that the {@link
* #keyFrameTime(int)} is set to the previous {@link #keyFrameTime(int)} plus one second (or 0.0
* if there is no previous keyFrame).
*/
public void addKeyFrame(GenericFrame frame) {
float time;
if (keyFrameList.isEmpty()) time = 0.0f;
else time = keyFrameList.get(keyFrameList.size() - 1).time() + 1.0f;
addKeyFrame(frame, time);
}
protected void updateCurrentKeyFrameForTime(float time) {
// Assertion: times are sorted in monotone order.
// Assertion: keyFrame_ is not empty
// TODO: Special case for loops when closed path is implemented !!
if (!currentFrmValid)
// Recompute everything from scratch
currentFrame1 = keyFrameList.listIterator();
// currentFrame_[1]->peekNext() <---> keyFr.get(currentFrame1.nextIndex());
while (keyFrameList.get(currentFrame1.nextIndex()).time() > time) {
currentFrmValid = false;
if (!currentFrame1.hasPrevious()) break;
currentFrame1.previous();
}
if (!currentFrmValid) currentFrame2 = keyFrameList.listIterator(currentFrame1.nextIndex());
while (keyFrameList.get(currentFrame2.nextIndex()).time() < time) {
currentFrmValid = false;
if (!currentFrame2.hasNext()) break;
currentFrame2.next();
}
if (!currentFrmValid) {
currentFrame1 = keyFrameList.listIterator(currentFrame2.nextIndex());
if ((currentFrame1.hasPrevious())
&& (time < keyFrameList.get(currentFrame2.nextIndex()).time())) currentFrame1.previous();
currentFrame0 = keyFrameList.listIterator(currentFrame1.nextIndex());
if (currentFrame0.hasPrevious()) currentFrame0.previous();
currentFrame3 = keyFrameList.listIterator(currentFrame2.nextIndex());
if (currentFrame3.hasNext()) currentFrame3.next();
currentFrmValid = true;
splineCacheIsValid = false;
}
}
/**
* 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();
}
/**
* Returns the time corresponding to the last keyFrame, expressed in seconds.
*
* <p>
*
* @see #firstTime()
* @see #duration()
* @see #keyFrameTime(int)
*/
public float lastTime() {
if (keyFrameList.isEmpty()) return 0.0f;
else return keyFrameList.get(keyFrameList.size() - 1).time();
}
/**
* Returns the time corresponding to the first keyFrame, expressed in seconds.
*
* <p>Returns 0.0 if the path is empty.
*
* @see #lastTime()
* @see #duration()
* @see #keyFrameTime(int)
*/
public float firstTime() {
if (keyFrameList.isEmpty()) return 0.0f;
else return keyFrameList.get(0).time();
}
/**
* Returns the time corresponding to the {@code index} keyFrame. index has to be in the range 0..
* {@link #numberOfKeyFrames()}-1.
*
* @see #keyFrame(int)
*/
public float keyFrameTime(int index) {
return keyFrameList.get(index).time();
}
/** 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;
}
}