陀螺仪

// ***********************************************************

// Written by Heyworks Unity Studio http://unity./

// ***********************************************************

using UnityEngine;

/// <summary>

/// Gyroscope controller that works with any device orientation.

/// </summary>

public class GyroController : MonoBehaviour

{

    #region [Private fields]

    private bool gyroEnabled = true;

    private const float lowPassFilterFactor = 0.2f;

    private readonly Quaternion baseIdentity = Quaternion.Euler(90, 0, 0);

    private readonly Quaternion landscapeRight = Quaternion.Euler(0, 0, 90);

    private readonly Quaternion landscapeLeft = Quaternion.Euler(0, 0, -90);

    private readonly Quaternion upsideDown = Quaternion.Euler(0, 0, 180);

    private Quaternion cameraBase = Quaternion.identity;

    private Quaternion calibration = Quaternion.identity;

    private Quaternion baseOrientation = Quaternion.Euler(90, 0, 0);

    private Quaternion baseOrientationRotationFix = Quaternion.identity;

    private Quaternion referanceRotation = Quaternion.identity;

    private bool debug = true;

    #endregion

    #region [Unity events]

    protected void Start()

    {

        AttachGyro();

    }

    protected void Update()

    {

        if (!gyroEnabled)

            return;

        transform.rotation = Quaternion.Slerp(transform.rotation,

            cameraBase * (ConvertRotation(referanceRotation * Input.gyro.attitude) * GetRotFix()), lowPassFilterFactor);

    }

    protected void OnGUI()

    {

        if (!debug)

            return;

        GUILayout.Label("Orientation: " + Screen.orientation);

        GUILayout.Label("Calibration: " + calibration);

        GUILayout.Label("Camera base: " + cameraBase);

        GUILayout.Label("input.gyro.attitude: " + Input.gyro.attitude);

        GUILayout.Label("transform.rotation: " + transform.rotation);

        if (GUILayout.Button("On/off gyro: " + Input.gyro.enabled, GUILayout.Height(100)))

        {

            Input.gyro.enabled = !Input.gyro.enabled;

        }

        if (GUILayout.Button("On/off gyro controller: " + gyroEnabled, GUILayout.Height(100)))

        {

            if (gyroEnabled)

            {

                DetachGyro();

            }

            else

            {

                AttachGyro();

            }

        }

        if (GUILayout.Button("Update gyro calibration (Horizontal only)", GUILayout.Height(80)))

        {

            UpdateCalibration(true);

        }

        if (GUILayout.Button("Update camera base rotation (Horizontal only)", GUILayout.Height(80)))

        {

            UpdateCameraBaseRotation(true);

        }

        if (GUILayout.Button("Reset base orientation", GUILayout.Height(80)))

        {

            ResetBaseOrientation();

        }

        if (GUILayout.Button("Reset camera rotation", GUILayout.Height(80)))

        {

            transform.rotation = Quaternion.identity;

        }

    }

    #endregion

    #region [Public methods]

    /// <summary>

    /// Attaches gyro controller to the transform.

    /// </summary>

    private void AttachGyro()

    {

        gyroEnabled = true;

        ResetBaseOrientation();

        UpdateCalibration(true);

        UpdateCameraBaseRotation(true);

        RecalculateReferenceRotation();

    }

    /// <summary>

    /// Detaches gyro controller from the transform

    /// </summary>

    private void DetachGyro()

    {

        gyroEnabled = false;

    }

    #endregion

    #region [Private methods]

    /// <summary>

    /// Update the gyro calibration.

    /// </summary>

    private void UpdateCalibration(bool onlyHorizontal)

    {

        if (onlyHorizontal)

        {

            var fw = (Input.gyro.attitude) * (-Vector3.forward);

            fw.z = 0;

            if (fw == Vector3.zero)

            {

                calibration = Quaternion.identity;

            }

            else

            {

                calibration = (Quaternion.FromToRotation(baseOrientationRotationFix * Vector3.up, fw));

            }

        }

        else

        {

            calibration = Input.gyro.attitude;

        }

    }

    /// <summary>

    /// Update the camera base rotation.

    /// </summary>

    /// <param name='onlyHorizontal'>

    /// Only y rotation.

    /// </param>

    private void UpdateCameraBaseRotation(bool onlyHorizontal)

    {

        if (onlyHorizontal)

        {

            var fw = transform.forward;

            fw.y = 0;

            if (fw == Vector3.zero)

            {

                cameraBase = Quaternion.identity;

            }

            else

            {

                cameraBase = Quaternion.FromToRotation(Vector3.forward, fw);

            }

        }

        else

        {

            cameraBase = transform.rotation;

        }

    }

    /// <summary>

    /// Converts the rotation from right handed to left handed.

    /// </summary>

    /// <returns>

    /// The result rotation.

    /// </returns>

    /// <param name='q'>

    /// The rotation to convert.

    /// </param>

    private static Quaternion ConvertRotation(Quaternion q)

    {

        return new Quaternion(q.x, q.y, -q.z, -q.w);

    }

    /// <summary>

    /// Gets the rot fix for different orientations.

    /// </summary>

    /// <returns>

    /// The rot fix.

    /// </returns>

    private Quaternion GetRotFix()

    {

#if UNITY_3_5

        if (Screen.orientation == ScreenOrientation.Portrait)

            return Quaternion.identity;

           

        if (Screen.orientation == ScreenOrientation.LandscapeLeft || Screen.orientation == ScreenOrientation.Landscape)

            return landscapeLeft;

                   

        if (Screen.orientation == ScreenOrientation.LandscapeRight)

            return landscapeRight;

                   

        if (Screen.orientation == ScreenOrientation.PortraitUpsideDown)

            return upsideDown;

        return Quaternion.identity;

#else

        return Quaternion.identity;

#endif

    }

    /// <summary>

    /// Recalculates reference system.

    /// </summary>

    private void ResetBaseOrientation()

    {

        baseOrientationRotationFix = GetRotFix();

        baseOrientation = baseOrientationRotationFix * baseIdentity;

    }

    /// <summary>

    /// Recalculates reference rotation.

    /// </summary>

    private void RecalculateReferenceRotation()

    {

        referanceRotation = Quaternion.Inverse(baseOrientation) * Quaternion.Inverse(calibration);

    }

    #endregion

}