onPinchUpdate method
Implementation
@override
void onPinchUpdate(PinchEvent event) {
if (updateCameraByPinchGestureEnabled) {
final scale = event.factorDistance;
gameRef.camera.zoom = _initialZoom * scale;
final diff = event.diffCenter;
gameRef.camera.position =
(_initialPosition - diff / (gameRef.camera.zoom));
}
super.onPinchUpdate(event);
}