XiuXianGame/Assets/FlatKit/Demos/Common/Scripts/Motion/OrbitMotion.cs

using UnityEngine;

namespace Dustyroom {
public class OrbitMotion : MonoBehaviour {
    public enum TargetMode {
        Transform,
        Position
    }

    public TargetMode targetMode = TargetMode.Position;
    public Transform targetTransform;
    public bool followTargetTransform = true;
    public Vector3 targetOffset = Vector3.zero;
    public Vector3 targetPosition;

    [Space] public float distanceHorizontal = 60.0f;
    public float distanceVertical = 60.0f;
    public float xSpeed = 120.0f;
    public float ySpeed = 120.0f;
    public float damping = 3f;

    [Space] public bool clampAngle = false;
    public float yMinLimit = -20f;
    public float yMaxLimit = 80f;

    [Space] public bool allowZoom = false;
    public float distanceMin = .5f;
    public float distanceMax = 15f;

    float _x = 0.0f;
    float _y = 0.0f;

    [Space] public bool autoMovement = false;
    public float autoSpeedX = 0.2f;
    public float autoSpeedY = 0.1f;
    public float autoSpeedDistance = -0.1f;

    [Space] public bool interactive = true;

    private float _lastMoveTime;
    [HideInInspector] public float timeSinceLastMove;

    void Start() {
        Vector3 angles = transform.eulerAngles;
        _x = angles.y;
        _y = angles.x;

        // Make the rigid body not change rotation
        Rigidbody rigidbody = GetComponent<Rigidbody>();
        if (rigidbody != null) {
            rigidbody.freezeRotation = true;
        }

#if (UNITY_ANDROID || UNITY_IOS) && !UNITY_EDITOR
        xSpeed *= 0.2f;
        ySpeed *= 0.2f;
#endif

        if (targetMode == TargetMode.Transform) {
            if (targetTransform != null) {
                targetPosition = targetTransform.position + targetOffset;
            }
            else {
                Debug.LogWarning("Reference transform is not set.");
            }
        }
    }

    void Update() {
        if (targetMode == TargetMode.Transform && followTargetTransform) {
            if (targetTransform != null) {
                targetPosition = targetTransform.position + targetOffset;
            }
            else {
                Debug.LogWarning("Reference transform is not set.");
            }
        }

        //*
        bool isCameraMoving = false;
#if ((UNITY_ANDROID || UNITY_IOS) && !UNITY_EDITOR)
        isCameraMoving = Input.GetTouch(0).deltaPosition.sqrMagnitude > 0f;
#else
        isCameraMoving = Mathf.Abs(Input.GetAxis("Mouse X")) + Mathf.Abs(Input.GetAxis("Mouse Y")) > 0f;
#endif
        if (isCameraMoving) {
            _lastMoveTime = Time.time;
        }

        timeSinceLastMove = Time.time - _lastMoveTime;
        //*/

        if (interactive && Input.GetMouseButton(0)) {
#if ((UNITY_ANDROID || UNITY_IOS) && !UNITY_EDITOR)
        _x += Input.GetTouch(0).deltaPosition.x * xSpeed * 40f * 0.02f;
        _y -= Input.GetTouch(0).deltaPosition.y * ySpeed * 40f * 0.02f;
#else
        _x += Input.GetAxis("Mouse X") * xSpeed * 40f * 0.02f;
        _y -= Input.GetAxis("Mouse Y") * ySpeed * 40f * 0.02f;
#endif
        }
        else if (autoMovement) {
            _x += autoSpeedX * 40f * Time.deltaTime * 10f;
            _y -= autoSpeedY * 40f * Time.deltaTime * 10f;
            distanceHorizontal += autoSpeedDistance;
        }

        if (clampAngle) {
            _y = ClampAngle(_y, yMinLimit, yMaxLimit);
        }

        Quaternion rotation = Quaternion.Slerp(transform.rotation, Quaternion.Euler(_y, _x, 0),
            Time.deltaTime * damping);

        if (allowZoom) {
            distanceHorizontal = Mathf.Clamp(
                distanceHorizontal - Input.GetAxis("Mouse ScrollWheel") * 5, distanceMin, distanceMax);
        }

        float rotationX = rotation.eulerAngles.x;
        if (rotationX > 90f) {
            rotationX -= 360f;
        }

        float usedDistance = Mathf.Lerp(distanceHorizontal, distanceVertical, Mathf.Abs(rotationX / 90f));
        Vector3 negDistance = new Vector3(0.0f, 0.0f, -usedDistance);
        Vector3 position = rotation * negDistance + targetPosition;

        transform.rotation = rotation;
        transform.position = position;
    }

    private static float ClampAngle(float angle, float min, float max) {
        if (angle < -360f)
            angle += 360f;
        if (angle > 360f)
            angle -= 360f;
        return Mathf.Clamp(angle, min, max);
    }
}
}