キャンバスをフェードするクラス【Unity】

CanvasFader.cs

//  CanvasFader.cs
//  http://kan-kikuchi.hatenablog.com/entry/SceneNavigator
//
//  Created by kan.kikuchi on 2017.05.14.

using UnityEngine;
using System;
using System.Collections;
using System.Collections.Generic;

[RequireComponent(typeof(CanvasGroup))]
/// <summary>
/// キャンバスをフェードするクラス
/// </summary>
public class CanvasFader : MonoBehaviour {

  //フェード用のキャンバスとそのアルファ値
  private CanvasGroup _canvasGroupEntity;
  private CanvasGroup _canvasGroup{
    get{
      if(_canvasGroupEntity == null){
        _canvasGroupEntity = GetComponent<CanvasGroup>();
        if(_canvasGroupEntity == null){
          _canvasGroupEntity = gameObject.AddComponent<CanvasGroup>();
        }
      }
      return _canvasGroupEntity;
    }
  }
  public float Alpha{
    get{
      return _canvasGroup.alpha;
    }
    set{
      _canvasGroup.alpha = value;
    }
  }

  //フェードの状態
  private enum FadeState{
    None, FadeIn, FadeOut
  }
  private FadeState _fadeState = FadeState.None;

  //フェードしているか
  public bool IsFading{
    get{return _fadeState != FadeState.None;}
  }

  //フェード時間
  [SerializeField]
  private float _duration;
  public  float  Duration{get{return _duration;}}

  //タイムスケールを無視するか
  [SerializeField]
  private bool _ignoreTimeScale = true;

  //フェード終了後のコールバック
  private event Action _onFinished = null;

  //=================================================================================
  //更新
  //=================================================================================

  private void Update (){
    if(!IsFading){
      return;
    }

    float fadeSpeed = 1f / _duration;
    if(_ignoreTimeScale){
      fadeSpeed *= Time.unscaledDeltaTime;
    }
    else{
      fadeSpeed *= Time.deltaTime;
    }

    Alpha += fadeSpeed * (_fadeState == FadeState.FadeIn ? 1f : -1f);

    //フェード終了判定
    if(Alpha > 0 && Alpha < 1){
      return;
    }

    _fadeState = FadeState.None;
    this.enabled = false;

    if(_onFinished != null){
      _onFinished();
    }
  }

  //=================================================================================
  //開始
  //=================================================================================

  /// <summary>
  /// 対象のオブジェクトのフェードを開始する
  /// </summary>
  public static void Begin(GameObject target, bool isFadeOut, float duration){
    CanvasFader canvasFader = target.GetComponent<CanvasFader>();
    if(canvasFader == null){
      canvasFader = target.AddComponent<CanvasFader>();
    }
    canvasFader.enabled = true;


    canvasFader.Play(isFadeOut, duration);
  }

  /// <summary>
  /// フェードを開始する
  /// </summary>
  public void Play(bool isFadeOut, float duration,  bool ignoreTimeScale = true, Action onFinished = null){
    this.enabled = true;

    _ignoreTimeScale = ignoreTimeScale;
    _onFinished      = onFinished;

    Alpha      = isFadeOut ? 1 : 0;
    _fadeState = isFadeOut ? FadeState.FadeOut :FadeState.FadeIn;

    _duration = duration;
  }

  //=================================================================================
  //停止
  //=================================================================================

  /// <summary>
  /// フェード停止
  /// </summary>
  public void Stop(){
    _fadeState = FadeState.None;
    this.enabled = false;
  }

}