# InteractionBox¶

Methods:

class Leap::InteractionBox

The InteractionBox class represents a box-shaped region completely within the field of view of the Leap Motion controller.

The interaction box is an axis-aligned rectangular prism and provides normalized coordinates for hands, fingers, and tools within this box. The InteractionBox class can make it easier to map positions in the Leap Motion coordinate system to 2D or 3D coordinate systems used for application drawing.

The InteractionBox region is defined by a center and dimensions along the x, y, and z axes.

Get an InteractionBox object from a Frame object.

Since
1.0

Public Functions

Vector center()

The center of the InteractionBox in device coordinates (millimeters).

This point is equidistant from all sides of the box.

Vector boxCenter = interactionBox.center();


Return
The InteractionBox center in device coordinates.
Since
1.0

Vector denormalizePoint(const Vector & normalizedPosition)

Converts a position defined by normalized InteractionBox coordinates into device coordinates in millimeters.

InteractionBox interactionBox = frame.interactionBox();
Vector point = Vector(100, 75, -125);
Vector normalizedCoordinates = interactionBox.normalizePoint(point, false);
Vector denormalizedCoordinates = interactionBox.denormalizePoint(normalizedCoordinates);
// denormalizedCoordinates == point


This function performs the inverse of normalizePoint().

Return
The corresponding denormalized position in device coordinates.
Since
1.0
Parameters
• normalizedPosition -

The input position in InteractionBox coordinates.

float depth()

The depth of the InteractionBox in millimeters, measured along the z-axis.

float boxDimensionAlongZAxis = interactionBox.depth();


Return
The InteractionBox depth in millimeters.
Since
1.0

float height()

The height of the InteractionBox in millimeters, measured along the y-axis.

float boxDimensionAlongYAxis = interactionBox.height();


Return
The InteractionBox height in millimeters.
Since
1.0

bool isValid()

Reports whether this is a valid InteractionBox object.

if (interactionBox.isValid()) {
//Use the box...
}


Return
True, if this InteractionBox object contains valid data.
Since
1.0

Vector normalizePoint(const Vector & position, bool clamp = true)

Normalizes the coordinates of a point using the interaction box.

Vector normalizedHandPosition = interactionBox.normalizePoint(hand.palmPosition());


Coordinates from the Leap Motion frame of reference (millimeters) are converted to a range of [0..1] such that the minimum value of the InteractionBox maps to 0 and the maximum value of the InteractionBox maps to 1.

Return
The normalized position.
Since
1.0
Parameters
• position -

The input position in device coordinates.

• clamp -

Whether or not to limit the output value to the range [0,1] when the input position is outside the InteractionBox. Defaults to true.

bool operator!=(const InteractionBox &)

Compare InteractionBox object inequality.

thisBox != thatBox;


Two InteractionBox objects are equal if and only if both InteractionBox objects represent the exact same InteractionBox and both InteractionBoxes are valid.

Since
1.0

bool operator==(const InteractionBox &)

Compare InteractionBox object equality.

thisBox == thatBox;


Two InteractionBox objects are equal if and only if both InteractionBox objects represent the exact same InteractionBox and both InteractionBoxes are valid.

Since
1.0

std::string toString()

A string containing a brief, human readable description of the InteractionBox object.

Return
A description of the InteractionBox as a string.
Since
1.0

float width()

The width of the InteractionBox in millimeters, measured along the x-axis.

float boxDimensionAlongXAxis = interactionBox.width();


Return
The InteractionBox width in millimeters.
Since
1.0

Public Static Functions

const InteractionBox & invalid()

Returns an invalid InteractionBox object.

You can use the instance returned by this function in comparisons testing whether a given InteractionBox instance is valid or invalid. (You can also use the InteractionBox::isValid() function.)

if (interactionBox != InteractionBox::invalid()) {
//Use the box...
}


Return
The invalid InteractionBox instance.
Since
1.0