initialize method
Implementation
void initialize(
PlayerControllerListener controller,
camera.Viewport viewPort,
) {
if (_screenSize == viewPort.virtualSize) return;
_viewPort = viewPort;
_screenSize = viewPort.virtualSize.clone();
_controller = controller;
final radius = size / 2;
final screenRect = Rect.fromLTRB(
margin.left + radius,
margin.top + radius,
_screenSize.x - margin.right - radius,
_screenSize.y - margin.bottom - radius,
);
Offset osBackground = alignment.withinRect(screenRect);
_backgroundRect = Rect.fromCircle(
center: osBackground,
radius: radius,
);
Offset osKnob = Offset(
_backgroundRect!.center.dx,
_backgroundRect!.center.dy,
);
_knobRect = Rect.fromCircle(
center: osKnob,
radius: size / 4,
);
_dragPosition = _knobRect!.center;
}