trackable-pointer.md 2.8KB
TrackablePointer
A trackable that represents a pointer tracked by a PointerTracker.
A pointer is an abstraction that represents an instance of user input that targets one or more coordinates on a screen. For example, each point of contact between fingers and a multitouch screen generate a pointer. Devices such as a mouse and a pen/stylus also generate pointers.
Pointers are located in the viewport. Their positions are given in space units. By default, space units are normalized units, which range from -1 to +1. In normalized space, the center of the viewport is at (0,0). The top right corner is at (1,1). The bottom left corner is at (-1,-1).
Since: 0.4.0
Properties
id
pointer.id: number, read-only
A unique identifier assigned to this pointer.
phase
pointer.phase: string, read-only
The phase of the pointer. It’s one of the following strings:
"began": the tracking began in this frame (e.g., a finger has just touched the screen)"stationary": the user did not move the pointer in this frame"moved": the user moved the pointer in this frame"ended": the tracking ended in this frame (e.g., a finger has just been lifted from the screen)"canceled": the tracking was canceled in this frame (e.g., the page has just lost focus)
position
pointer.position: Vector2, read-only
The current position of the pointer, given in space units. See also: PointerTracker.space, Viewer.raycast, Viewport.convertToPixels.
initialPosition
pointer.initialPosition: Vector2, read-only
The position of the pointer when its tracking began.
deltaPosition
pointer.deltaPosition: Vector2, read-only
The difference between the position of the pointer in this and in the previous frame.
velocity
pointer.velocity: Vector2, read-only
The current velocity of the pointer, given in space units per second. You can get the current speed of motion by calculating the magnitude of this vector.
duration
pointer.duration: number, read-only
The elapsed time, in seconds, since the tracking of this pointer began.
totalDistance
pointer.totalDistance: number, read-only
How much this pointer has moved, in space units, since its tracking began. You can get the average speed of motion by calculating the ratio totalDistance / duration.
isPrimary
pointer.isPrimary: boolean, read-only
Whether or not this is the primary pointer among all pointers of this type. A typical primary pointer is that of a finger that touches the screen when no other fingers are touching it.
kind
pointer.kind: string, read-only
The type of device that originated this pointer. Typically "touch", "mouse" or "pen".