Function computeArcballRotation

computeArcballRotation(
    startNDC: Vector2,
    endNDC: Vector2,
    trackballRadius: number,
    rotateSpeed: number,
): Quaternion
Compute rotation quaternion from arcball drag (start → end in NDC).
Parameters
- startNDC: Vector2
- endNDC: Vector2
- trackballRadius: number
- rotateSpeed: number
Returns Quaternion
- Defined in src/controls/luxar-orbit-controls/math/trackball.ts:26