Touhou/client/Assets/Game/Scripts/ECS/System/ViewSystem.cs

using Entitas;
using UnityEngine;
using Game;
using Vector3 = UnityEngine.Vector3;

// view的3d转2d的表现在此处理
public class ViewSystem : IExecuteSystem, IInitializeSystem
{
    private IGroup<GameEntity> _entities;

    public void Initialize()
    {
        _entities = Util.GetGroup(GameMatcher.View);
    }

    public void Execute()
    {
        foreach (var entity in _entities)
        {
            UpdateShake(entity); //更新抖动
            UpdateViewPos(entity); //更新位置
            if (Util.IsPause(entity))
            {
                continue;
            }

            UpdateActive(entity); //更新显示
        }
    }

    private static void UpdateActive(GameEntity entity)
    {
        var view = entity.view;
        var entityItem = view.EntityPoolItem;
        if (entityItem.IsAlive && !entityItem.GameObject.activeSelf)
        {
            entityItem.GameObject.SetActive(true);
        }
    }

    private static void UpdateShake(GameEntity entity)
    {
        var view = entity.view;
        if (view.ShakeTimeLeft == 0)
        {
            return;
        }

        view.ShakeTimeLeft -= Time.unscaledDeltaTime;
        if (view.ShakeTimeLeft < 0)
        {
            view.ShakeTimeLeft = 0;
            view.LocalPositionShake = Vector3.zero;
            return;
        }

        var shakeDist = Mathf.Sin(view.ShakeTimeLeft * GameConst.ShakeRate) * GameConst.ShakeDistance;
        view.LocalPositionShake = new Vector3(shakeDist, 0, 0);
    }

    private static void UpdateViewPos(GameEntity entity)
    {
        var view = entity.view;
        view.PositionPre = entity.Pos();
        var transView = view.TransformViewMain;
        transView.localPosition = view.LocalPositionShake + view.LocalPositionOrder;
        view.PosView.Value = transView.position;
    }
}