/**
Returns
1 if abs(xvel) <= 1/2 abs(yvel)
0 otherwise
*/
virtual int evaluate(const Leap::Frame &frame,
const std::string& nodeid) {
Leap::Hand h = frame.hand(0);
if (h.isValid()) {
Leap::Vector vel = h.palmVelocity();
return (abs(vel.x) <= 0.5 * abs(vel.y))
? 1 : 0;
} else
return 0;
}
void MouseListener::onFrame(const Leap::Controller &controller) {
// get list of detected screens
const Leap::ScreenList screens = controller.calibratedScreens();
// make sure we have a detected screen
if (screens.empty()) return;
const Leap::Screen screen = screens[0];
// get hands
const Leap::Frame frame = controller.frame();
const Leap::HandList hands = frame.hands();
if (hands.empty()) return;
// which is the pointer hand and which is the clicker hand?
// if there's only one hand it's the pointer hand. if there's two
// then we'll use the user's primary hand. if ambidextrous, bail.
Leap::Hand pointerHand, clickerHand;
if (pointerHandID) {
pointerHand = frame.hand(pointerHandID);
if (! pointerHand.isValid())
pointerHand = hands[0];
}
if (clickerHandID)
clickerHand = frame.hand(clickerHandID);
if (! clickerHand.isValid() && hands.count() == 2) {
// figure out clicker and pointer hand
// which hand is on the left and which is on the right?
Leap::Hand leftHand, rightHand;
if (hands[0].palmPosition()[0] <= hands[1].palmPosition()[0]) {
leftHand = hands[0];
rightHand = hands[1];
} else {
leftHand = hands[1];
rightHand = hands[0];
}
// now that we know the left and right hands, determine
// which is the clicker and which is the pointer
if (leftHanded) {
pointerHand = leftHand;
clickerHand = rightHand;
} else {
pointerHand = rightHand;
clickerHand = leftHand;
}
// keep track of which hands we decided on
clickerHandID = clickerHand.id();
pointerHandID = pointerHand.id();
}
// find the first finger or tool
const Leap::PointableList pointables = pointerHand.pointables();
if (pointables.empty()) return;
const Leap::Pointable firstPointable = pointables[0];
// get x, y coordinates on the first screen
const Leap::Vector intersection = screen.intersect(
firstPointable,
true, // normalize
1.0f // clampRatio
);
// if the user is not pointing at the screen all components of
// the returned vector will be Not A Number (NaN)
// isValid() returns true only if all components are finite
if (! intersection.isValid()) return;
unsigned int x = screen.widthPixels() * intersection.x;
// flip y coordinate to standard top-left origin
unsigned int y = screen.heightPixels() * (1.0f - intersection.y);
// move cursor to location pointed at
CGPoint destPoint = CGPointMake(x, y);
CGDisplayMoveCursorToPoint(kCGDirectMainDisplay, destPoint);
// check for click gesture
if (! clickerHand.isValid()) return;
// click = two fingers on the clicker hand touching together
const Leap::PointableList clickerFingers = clickerHand.pointables();
if (clickerFingers.count() != 2) return;
// get finger distance
float clickFingerDistance = clickerFingers[0].tipPosition().distanceTo(
clickerFingers[1].tipPosition()
);
cout << "distance: " << clickFingerDistance << endl;
if (! clickActive && clickFingerDistance < clickActivationDistance) {
clickActive = true;
cout << "mouseDown\n";
postMouseDown(x, y);
} else if (clickActive && clickFingerDistance > clickActivationDistance) {
cout << "mouseUp\n";
clickActive = false;
postMouseUp(x, y);
}
}