LeapPointable¶

Properties:

Methods:

The LeapPointable class reports the physical characteristics of a detected finger or tool.

Both fingers and tools are classified as LeapPointable objects. Use the [LeapPointable isFinger] function to determine whether a pointable object represents a finger. The Leap classifies a detected entity as a tool when it is thinner, straighter, and longer than a typical finger.

To provide touch emulation, the Leap Motion software associates a floating touch plane that adapts to the user’s finger movement and hand posture. The Leap Motion interprets purposeful movements toward this plane as potential touch points. The logic used by the LeapPointable class is the same as that used by the Leap Motion software for OS-level touch and mouse input emulation.

Note that LeapPointable objects can be invalid, which means that they do not contain valid tracking data and do not correspond to a physical entity. Invalid LeapPointable objects can be the result of asking for a pointable object using an ID from an earlier frame when no pointable objects with that ID exist in the current frame. A pointable object created from the LeapPointable constructor is also invalid. Test for validity with the [LeapPointable isValid] function.

Since 1.0

Property

- (LeapVector *) direction

direction

The direction in which this finger or tool is pointing.

LeapVector *direction = pointable.direction;

The direction is expressed as a unit vector pointing in the same direction as the tip.

Return

The LeapVector pointing in the same direction as the tip of this LeapPointable object.

Since 1.0

- (LeapFrame *) frame

frame

The LeapFrame associated with this LeapPointable object.

LeapFrame *owningFrame = pointable.frame;

This property is a weak reference to the LeapFrame object so it is only valid during the lifetime of the LeapFrame object while the LeapFrame object is in the history buffer or while your application maintains its own reference.

Return

The associated LeapFrame object, if available; otherwise, an invalid LeapFrame object is returned.

Since 1.0

- (LeapHand *) hand

hand

The LeapHand associated with a finger.

LeapHand *owningHand = pointable.hand;

This property is a weak reference to the LeapHand object so it is only valid during the lifetime of that LeapHand object in other words, while the parent LeapFrame object is valid or while your application maintains its own reference.

As of version 2, tools are not associated with hands, so this property always returns an invalid LeapHand object for tools.

Return

The associated LeapHand object, if available; otherwise, an invalid LeapHand object is returned.

Since 1.0

- (int32_t) id

id

A unique ID assigned to this LeapPointable object, whose value remains the same across consecutive frames while the tracked finger or tool remains visible.

If tracking is lost, the Leap may assign a new ID when it detects the entity in a future frame.

int id = pointable.id;

Use the ID value with the [LeapFrame pointable:] function to find this LeapPointable object in future frames.

int idOfInterest = 201;
LeapPointable *pointableOfInterest = [frame pointable:idOfInterest];

Return

The ID assigned to this LeapPointable object.

Since 1.0

- (BOOL) isExtended

isExtended

Whether or not this Pointable is in an extended posture.

int extendedCount = 0;
for (LeapPointable *pointable in frame.pointables) {
  if (pointable.isExtended) {
    extendedCount++;
  }
}

A finger is considered extended if it is extended straight from the hand as if pointing. A finger is not extended when it is bent down and curled towards the palm.

Return

True, if the pointable is extended.

Since 2.0

- (BOOL) isFinger

isFinger

Whether or not the LeapPointable is classified a finger.

if (pointable.isFinger) {
  LeapFinger *finger = (LeapFinger *)pointable;
}

Return

YES, if this LeapPointable is classified as a LeapFinger.

Since 1.0

- (BOOL) isTool

isTool

Whether or not the LeapPointable is classified to be a tool.

if (pointable.isTool) {
  LeapTool *tool = (LeapTool *)pointable;
}

Return

NO

- (BOOL) isValid

isValid

Reports whether this is a valid LeapPointable object.

if(pointable.isValid){
    //Use the data
}

Return

YES, if this LeapPointable object contains valid tracking data.

Since 1.0

- (float) length

length

The estimated length of the finger or tool in millimeters.

The reported length is the visible length of the finger or tool. If the length isn’t known, then a value of 0 is returned.

float length = pointable.length;

Return

The estimated length of this LeapPointable object.

Since 1.0

- (LeapVector *) stabilizedTipPosition

stabilizedTipPosition

The stabilized tip position of this LeapPointable.

LeapVector *stabilizedPosition = pointable.stabilizedTipPosition;

Smoothing and stabilization is performed in order to make this value more suitable for interaction with 2D content.

Since 1.0

- (float) timeVisible

timeVisible

The duration of time this Pointable has been visible to the Leap Motion Controller.

float lifetime = pointable.timeVisible;

Return

The duration (in seconds) that this Pointable has been tracked.

Since 1.0

- (LeapVector *) tipPosition

tipPosition

The tip position in millimeters from the Leap origin.

LeapVector *position = pointable.tipPosition;

Return

The LeapVector containing the coordinates of the tip position.

Since 1.0

- (LeapVector *) tipVelocity

tipVelocity

The rate of change of the tip position in millimeters/second.

LeapVector *speed = pointable.tipVelocity;

Return

The LeapVector containing the coordinates of the tip velocity.

Since 1.0

- (float) touchDistance

touchDistance

A value proportional to the distance between this LeapPointable object and the adaptive touch plane.

float touchDistance = pointable.touchDistance;

- (LeapPointableZone) touchZone

touchZone

The current touch zone of this LeapPointable object.

LeapPointableZone zone = pointable.touchZone;

- (float) width

width

The estimated width of the finger or tool in millimeters.

The reported width is the average width of the visible portion of the finger or tool. If the width isn’t known, then a value of 0 is returned.

float width = pointable.width;

Return

The estimated width of this LeapPointable object.

Since 1.0

Public Static Functions

+ (LeapPointable *) invalid

Returns an invalid LeapPointable object.

LeapPointable *pointer = LeapPointable.invalid;

Return

The invalid LeapPointable instance.

Since 1.0