TouchUtils

Utility class for handling touch events, e.g.

Type	Name	Interface Description
Static Functions	getPinchEmitter(): IEventEmitter	• Function: Retrieves the event emitter associated with pinch. Returns The event emitter for the pinch, which can be used to subscribe to pinch events defined in IPinchInfo.
Static Functions	isScreenPointOnImage(screenPoint: Vector2f, image: Image): boolean	• Function: Whether a normalized touch point is on an image. Parameters • screenPoint: A normalized screen point in the range [0, 1], typically from TouchData.position. (0, 0) is the top-left corner of the screen; (1, 1) is the bottom-right corner; x increases rightward and y increases downward. This is not the pixel-based screen space used by camera conversion APIs such as Camera.screenToWorldPoint (which uses bottom-left origin with y increasing upward). • image: The image component to judge. The image should be enabled and have a valid screen transform component. It should be rendered by a camera with the Orthographic type. Returns True if the normalized touch point is on the image, otherwise false.

Examples

getPinchEmitter(): IEventEmitter

const emitter = APJS.TouchUtils.getPinchEmitter();
const callback = (event: APJS.IEvent) => {
  const pinchInfo = event.args[0] as APJS.IPinchInfo;
  const { scale, angle } = pinchInfo;
  // Do something with scale and angle, e.g. scale and rotate the image.
  this.imageTransform.scale = new APJS.Vector2f(scale, scale);
  this.imageTransform.rotation = angle * 180 / Math.PI;
}
emitter.on(0, callback); // The pinch emitter ignores eventName, so any number can be used.

isScreenPointOnImage(screenPoint: Vector2f, image: Image): boolean

let callback = (event:APJS.IEvent) => {
    const touchInfo = event.args[0] as APJS.TouchData;
    if (touchInfo.phase === APJS.TouchPhase.Began && APJS.TouchUtils.isScreenPointOnImage(touchInfo.position, this.imageComponent)) {
        ...
    }
}
const globalEmitter = APJS.EventManager.getGlobalEmitter();
globalEmitter.on(APJS.EventType.Touch, callback);

Use Case

@component()
export class NewBehaviourScript extends APJS.BasicScriptComponent {
  onStart() {
    // TODO: instantiate / use TouchUtils here
  }
  onUpdate(deltaTime: number) {
  }
}