Function zoom2D

packages/engine/Source/Scene/ScreenSpaceCameraController.js:1010–1025

(controller, startPosition, movement)

}

function zoom2D(controller, startPosition, movement) {
  if (defined(movement.distance)) {
    movement = movement.distance;
  }

  const scene = controller._scene;
  const camera = scene.camera;

  handleZoom(
    controller,
    startPosition,
    movement,
    controller.zoomFactor,
    camera.getMagnitude(),
  );
}

const twist2DStart = new Cartesian2();
const twist2DEnd = new Cartesian2();