// Returns the distance between the index finger and thumb of the rightmost
// hand in the field of view of the Leap Motion sensor
private Double getGripDistance(Frame frame) {
Double gripDist = -1.0;
if (frame.isValid()) {
if (!frame.hands().isEmpty() && frame.fingers().count() >= 2) {
// right hand used to control arm
Hand rightHand = frame.hands().rightmost();
// get the two fingers with smallest X co-ords
Finger thumb = null, index = null;
Float minX = 9999f, minX2 = minX;
Iterator<Finger> it = rightHand.fingers().iterator();
while (it.hasNext()) {
Finger finger = it.next();
Float tipXPos = finger.stabilizedTipPosition().getX();
if (tipXPos < minX) {
minX2 = minX;
index = thumb;
minX = tipXPos;
thumb = finger;
} else if (tipXPos < minX2) {
minX2 = tipXPos;
index = finger;
}
}
Vector thumbTip = thumb.stabilizedTipPosition();
Vector indexTip = index.stabilizedTipPosition();
gripDist = (double) thumbTip.distanceTo(indexTip);
}
}
return gripDist;
}
// Returns the orientation of the palm given a frame of data
// The double returned is a real number between 0 and 1 indicating
// the component of the normal to the palm on the plane of the
// computer screen
private Double getPalmOrientation(Frame frame) {
Double armOrt = -1.0;
if (frame.isValid()) {
if (!frame.hands().isEmpty()) {
Vector normal = frame.hands().rightmost().palmNormal();
armOrt = Math.sqrt(normal.getX() * normal.getX() + normal.getY() * normal.getY());
}
}
return armOrt;
}
// Checks if the user wants to lock the position of the gripper
// For locking the gripper, there need to be at least two hands in the
// sensor's field of view, and the leftmost hand must have no fingers
// outstretched (clenched fist with the back of the hand facing the sensor)
private boolean checkGripperLock(Frame frame) {
boolean locked = false;
if (frame.isValid()) {
if (frame.hands().count() > 1) {
Hand leftHand = frame.hands().leftmost();
if (leftHand.fingers().isEmpty()) locked = true;
}
}
return locked;
}
