using UnityEngine;

namespace Thousandto.Launcher.ExternalLibs
{
    /// <summary>
    /// 小草的动画  
    /// </summary>
    public class GrassAnimateScript : VertexAnimateBaseScript
    {
        #region//私有变量
        //一个随机值
        private float _randNum;
        //风的时间
        public float _windTime = Mathf.PI * 2f;
        //开始摆动计时
        public float _time = 0f;
        //偏移值
        public float _offset = 1.4f;
        //限制最小摆动因子的分母
        public int _dePow = 5; 
        //碰撞力度
        public Vector2 _power = Vector2.one;
        //顶点移动方向向量
        private Vector3 _dir = Vector3.zero;

        #endregion

        #region//重写MonoBehaviour

        private void OnDisable()
        {
            Stop();
        }

        //进入触发器
        void OnTriggerEnter(Collider other)
        {   
            Vector3 dir = transform.position - other.transform.position;
            //碰撞方向向量
            _dir = transform.parent.InverseTransformDirection(dir);
            dir = _dir;
            if (other is CapsuleCollider)
            {
                var box = other as CapsuleCollider;// UnityUtils.RequireComponent<CapsuleCollider>(other.gameObject);
                //碰撞力度
                if (box != null)
                {
                    if (dir.x > box.radius)
                        dir.x = box.radius;
                    if (dir.z > box.radius)
                        dir.z = box.radius;
                    if (dir.x < box.radius / _dePow)
                        dir.x = box.radius / _dePow;
                    if (dir.z < box.radius / _dePow)
                        dir.z = box.radius / _dePow;
                    float pow_x = Mathf.Abs(dir.x / box.radius);
                    float pow_y = Mathf.Abs(dir.z / box.radius);
                    float cos_x = Mathf.Cos(pow_x);
                    float cos_y = Mathf.Cos(pow_y);
                    _power.x = (1 - pow_x) * _offset * cos_x;
                    _power.y = (1 - pow_y) * _offset * cos_y;
                }
            }
            _dir = _dir.normalized;
            Play();
        }
        #endregion

        #region//重写函数
        protected override void OnStart()
        {
            _windTime = Mathf.PI * 2f;
            _randNum = UnityEngine.Random.Range(1f, 3f);

            base.OnStart();
        }

        //刷新顶点之前
        protected override bool OnRefreshVertexBefore(ref Vector3 datVertex)
        {
            //计算频率
            var _frequency = (1.0f - _windTime / (Mathf.PI * 2f)) * 0.7f;
            //根据时间获取一个角度
            //x移动的位置是一个角度的Sin信息
            datVertex.x = _dir.x * Mathf.Sin(_time) * _frequency * _power.x;
            //y方向不做变化
            datVertex.y = 0;
            //z移动的位置是角度+90度后的一个角度的Sin值.x和z的移动方向是垂直的
            datVertex.z = _dir.z * Mathf.Sin(_time) * _frequency * _power.y;

            return true;           
        }

        //刷新顶点后的处理
        protected override void OnRefreshVertexAfter(ref Vector3 datVertex)
        {
            if (_windTime < Mathf.PI * 2f)
            {
                _windTime += 0.04f;
                _time += Time.deltaTime + 0.1f;
            }
            else
            {  
                Stop();
            }
        }

        //播放
        protected override void Play()
        {
            _time = 0f;
            _windTime = 0;
            base.Play();
        }

        //停止
        protected override void Stop()
        {
            _time = 0f;
            _windTime = Mathf.PI * 2f;
            base.Stop();
        }
       
        #endregion
    }
}