CircleGestureΒΆ

Properties:

Methods:

class Leap::CircleGesture

The CircleGesture classes represents a circular finger movement.

A circle movement is recognized when the tip of a finger draws a circle within the Leap Motion Controller field of view.

api/../../../images/Leap_Gesture_Circle.png

Important: To use circle gestures in your application, you must enable recognition of the circle gesture. You can enable recognition with:

controller.EnableGesture (Gesture.GestureType.TYPE_CIRCLE);

Circle gestures are continuous. The CircleGesture objects for the gesture have three possible states:

State::STATE_START The circle gesture has just started. The movement has progressed far enough for the recognizer to classify it as a circle.

State::STATE_UPDATE The circle gesture is continuing.

State::STATE_STOP The circle gesture is finished.

You can set the minimum radius and minimum arc length required for a movement to be recognized as a circle using the config attribute of a connected Controller object. Use the following keys to configure circle recognition:

Key string Value type Default value Units
Gesture.Circle.MinRadius float 5.0 mm
Gesture.Circle.MinArc float 1.5 * pi radians

The following example demonstrates how to set the circle configuration parameters:

controller.Config.SetFloat ("Gesture.Circle.MinRadius", 10.0f);
controller.Config.SetFloat ("Gesture.Circle.MinArc", .5f);
controller.Config.Save ();

The Controller object must be connected to the Leap Motion service/daemon before setting the configuration parameters.

Since
1.0

Public Functions

CircleGesture()

Constructs a new CircleGesture object.

An uninitialized CircleGesture object is considered invalid. Get valid instances of the CircleGesture class from a Frame object.

Since
1.0

CircleGesture(Gesture rhs)

Constructs a CircleGesture object from an instance of the Gesture class.

if (gesture.Type == Gesture.GestureType.TYPE_CIRCLE) {
    CircleGesture circleGesture = new CircleGesture (gesture);
}

Since
1.0
Parameters

Property

Vector Center

The center point of the circle within the Leap Motion frame of reference.

Vector centerPoint = circle.Center;
Return
Vector The center of the circle in mm from the Leap Motion origin.
Since
1.0

Vector Normal

Returns the normal vector for the circle being traced.

If you draw the circle clockwise, the normal vector points in the same general direction as the pointable object drawing the circle. If you draw the circle counterclockwise, the normal points back toward the pointable. If the angle between the normal and the pointable object drawing the circle is less than 90 degrees, then the circle is clockwise.

String clockwiseness;
if (circle.Pointable.Direction.AngleTo (circle.Normal) <= Math.PI / 2) {
    clockwiseness = "clockwise";
} else {
    clockwiseness = "counterclockwise";
}

Return
Vector the normal vector for the circle being traced
Since
1.0

Pointable Pointable

The finger performing the circle gesture.

Pointable circlePointable = circle.Pointable;

Return
Pointable A Pointable object representing the circling finger.
Since
1.0

float Progress

The number of times the finger tip has traversed the circle.

Progress is reported as a positive number of the number. For example, a progress value of .5 indicates that the finger has gone halfway around, while a value of 3 indicates that the finger has gone around the the circle three times.

float turns = circle.Progress;

Progress starts where the circle gesture began. Since the circle must be partially formed before the Leap Motion software can recognize it, progress will be greater than zero when a circle gesture first appears in the frame.

Return
float A positive number indicating the gesture progress.
Since
1.0

float Radius

The radius of the circle.

float diameter = 2 * circle.Radius;

Return
The circle radius in mm.
Since
1.0

Public Static Functions

The circle gesture type.

if (gesture.Type == CircleGesture.ClassType ()) {
    CircleGesture circleGesture = new CircleGesture (gesture);
}

Return
Type The type value designating a circle gesture.
Since
1.0