/**
* Creates a Transform that is a snapshot of the absolute position of this transform
*
* @return the snapshot
*/
@Threadsafe
public Transform getAbsolutePosition() {
while (true) {
int seq = lock.readLock();
if (parent == null) {
Transform r = copy();
if (lock.readUnlock(seq)) {
return r;
}
} else {
Transform r = createSum(parent.get().getAbsolutePosition());
if (lock.readUnlock(seq)) {
return r;
}
}
}
}
/**
* Gets a String representation of this transform
*
* @return the string
*/
@Override
@Threadsafe
public String toString() {
while (true) {
int seq = lock.readLock();
String s = getClass().getSimpleName() + "{" + position + ", " + rotation + ", " + scale + "}";
if (lock.readUnlock(seq)) {
return s;
}
}
}
/**
* Atomically gets the parent of this Transform
*
* @return the parent
*/
@Threadsafe
public Transform getParent() {
while (true) {
int seq = lock.readLock();
Transform result = null;
try {
result = parent.get();
} finally {
if (lock.readUnlock(seq)) {
return result;
}
}
}
}
/**
* Creates a Transform that is a copy of this transform
*
* @return the snapshot
*/
@Threadsafe
public Transform copy() {
Transform t = new Transform();
while (true) {
int seq = lock.readLock();
t.setPosition(position);
t.setRotation(rotation);
t.setScale(scale);
t.setParent(parent.get());
if (lock.readUnlock(seq)) {
return t;
}
}
}
/**
* Creates a Transform that is the sum of this transform and the given transform
*
* @param t the transform
* @return the new transform
*/
@Threadsafe
public Transform createSum(Transform t) {
Transform r = new Transform();
while (true) {
int seq = lock.readLock();
r.setPosition(position.add(t.getPosition()));
r.setRotation(rotation.multiply(t.getRotation()));
r.setScale(scale.add(t.getScale()));
r.setParent(parent.get());
if (lock.readUnlock(seq)) {
return r;
}
}
}
/**
* Unlocks the optimistic read lock
*
* @param sequence the sequence number returned by readLock()
* @return true if the Transform hasn't changed
*/
public boolean readUnlock(int sequence) {
return lock.readUnlock(sequence);
}