Unity - マウスドラッグでカメラを回転させる（一人称視点）

カメラをマウスドラッグで回転（一人称視点）させるサンプルスクリプト。

public class CameraRotator1stPersonPov : MonoBehaviour
{
    public Vector2 rotationSpeed = new Vector2(0.1f, 0.1f);
    public bool reverse;

    private Camera mainCamera;
    private Vector2 lastMousePosition;
    private Vector2 newAngle = Vector2.zero;

    void Start()
    {
        mainCamera = Camera.main;
    }

    void Update()
    {
        if (Input.GetMouseButtonDown(0))
        {
            newAngle = mainCamera.transform.localEulerAngles;
            lastMousePosition = Input.mousePosition;
        }
        else if (Input.GetMouseButton(0))
        {
            if (!reverse)
            {
                newAngle.y -= (lastMousePosition.x - Input.mousePosition.x) * rotationSpeed.y;
                newAngle.x -= (Input.mousePosition.y - lastMousePosition.y) * rotationSpeed.x;

                mainCamera.transform.localEulerAngles = newAngle;
                lastMousePosition = Input.mousePosition;
            }
            else
            {
                newAngle.y -= (Input.mousePosition.x - lastMousePosition.x) * rotationSpeed.y;
                newAngle.x -= (lastMousePosition.y - Input.mousePosition.y) * rotationSpeed.x;

                mainCamera.transform.localEulerAngles = newAngle;
                lastMousePosition = Input.mousePosition;
            }
        }
    }
}