Unity中制作游戏的快照游戏支持玩家拍快照

Unity中制作游戏的快照游戏支持玩家拍快照

有些游戏支持玩家“拍快照”，也就是将游戏的精彩瞬间以图片的形式记录下来的功能。这个功能比较有趣，而且以后的用途也会很广，为此本节打算介绍：截取矩形区域内游戏视图，并将其显示在视图其它区域的方法。具体的操作步骤如下本文选自Unity游戏开发技巧集锦：

（1）在Project视图里，创建一个C#脚本文件，并命名为ScreenTexture。在此脚本中编写如下的代码：

• 01     using UnityEngine;
• 02     using System.Collections;
• 03
• 04     public class ScreenTexture : MonoBehaviour
• 05     {
• 06              //公有成员
• 07              public int photoWidth = 50;                                    //矩形的宽度
• 08              public int photoHeight = 50;                                  //矩形的高度
• 09              public int thumbProportion = 25;                          //截图的显示比例
• 10              public Color borderColor = Color.white;             //矩形框架的颜色
• 11              public int borderWidth = 2;                                              //矩形框的宽度
• 12              //私有成员
• 13              private Texture2D texture;
• 14              private Texture2D border;
• 15              private int screenWidth;
• 16              private int screenHeight;
• 17              private int frameWidth;
• 18              private int frameHeight;
• 19              private bool shoot = false;
• 20              // 脚本初始化时，调用此函数
• 21              void Start ()
• 22              {
• 23                       screenWidth = Screen.width;
• 24                       screenHeight = Screen.height;
• 25                       frameWidth = Mathf.RoundToInt(screenWidth * photoWidth * 0.01f);
• 26                       frameHeight = Mathf.RoundToInt(screenHeight * photoHeight * 0.01f);
• 27                       texture = new Texture2D (frameWidth,frameHeight,TextureFormat.RGB24,false);
• 28                       border = new Texture2D (1,1,TextureFormat.ARGB32, false);
• 29                       border.SetPixel(0,0,borderColor);
• 30                       border.Apply();
• 31              }
• 32              // 运行游戏时，每帧都调用此函数
• 33              void Update ()
• 34              {
• 35                        //鼠标左键按下的时候
• 36                       if (Input.GetKeyUp(KeyCode.Mouse0))
• 37                                 StartCoroutine(CaptureScreen());
• 38              }
• 39              //在Game视图上，绘制纹理
• 40              void OnGUI ()
• 41              {
• 42                        //绘制矩形框的四个边
• 43                       GUI.DrawTexture(
• 44                                                   new Rect(
• 45                                                             (screenWidth*0.5f)-(frameWidth*0.5f) - borderWidth*2,
• 46                                                             ((screenHeight*0.5f)-(frameHeight*0.5f)) - borderWidth,
• 47                                                             frameWidth + borderWidth*2,
• 48                                                             borderWidth),
• 49                                                   border,ScaleMode.StretchToFill);
• 50                       GUI.DrawTexture(
• 51                                                   new Rect(
• 52                                                             (screenWidth*0.5f)-(frameWidth*0.5f) - borderWidth*2,
• 53                                                             (screenHeight*0.5f)+(frameHeight*0.5f),
• 54                                                             frameWidth + borderWidth*2,
• 55                                                             borderWidth),
• 56                                                   border,ScaleMode.StretchToFill);
• 57                       GUI.DrawTexture(
• 58                                                   new Rect(
• 59                                                             (screenWidth*0.5f)-(frameWidth*0.5f)- borderWidth*2,
• 60                                                             (screenHeight*0.5f)-(frameHeight*0.5f),
• 61                                                             borderWidth,
• 62                                                             frameHeight),
• 63                                                   border,ScaleMode.StretchToFill);
• 64                       GUI.DrawTexture(
• 65                                                   new Rect(
• 66                                                             (screenWidth*0.5f)+(frameWidth*0.5f),
• 67                                                             (screenHeight*0.5f)-(frameHeight*0.5f),
• 68                                                             borderWidth,
• 69                                                             frameHeight),
• 70                                                   border,ScaleMode.StretchToFill);
• 71                        //绘制矩形框中截取到的Game视图
• 72                       if(shoot)
• 73                       {
• 74                                 GUI.DrawTexture(
• 75                                                   new Rect (
• 76                                                             10,
• 77                                                             10,
• 78                                                             frameWidth*thumbProportion*0.01f,
• 79                                                             frameHeight*thumbProportion* 0.01f),
• 80                                                   texture,ScaleMode.StretchToFill);
• 81                       }
• 82              }
• 83              //截取矩形框里的Game视图
• 84              IEnumerator CaptureScreen ()
• 85              {
• 86                       yield return new WaitForEndOfFrame();
• 87                       texture.ReadPixels(
• 88                                 new Rect(
• 89                                          (screenWidth*0.5f)-(frameWidth*0.5f),
• 90                                (screenHeight*0.5f)-(frameHeight*0.5f),
• 91                                frameWidth,
• 92                                          frameHeight),
• 93                                 0,0);
• 94                       texture.Apply();
• 95                       shoot = true;
• 96              }
• 97     }

脚本代码中，40行的OnGUI()函数，使用GUI.DrawTexture()绘制了矩形框，以及矩形框中截取到的游戏视图；84行的CaptureScreen()函数，使用texture.ReadPixels()读取矩形框中的所有像素点，然后存储到texture中。触发“拍照”功能的操作是，在Game视图中的任意位置，单击鼠标左键，即36行代码实现的功能。

（2）将脚本ScreenTexture赋予Main Camera，然后选中Main Camera，在Inspector视图里可以设置脚本组件的一些属性，如图2-19所示本文选自Unity游戏开发技巧集锦。

图2-19  Main Camera上ScreenTexture脚本组件的各属性       图2-20  当前的Scene视图

（3）为游戏的场景添加一些几何体，并调整它们各自的位置，如图2-20所示。

（4）运行游戏，当在Game视图中的任意位置，单击鼠标左键的时候，可在视图的左上角看到矩形框中截取到的游戏视图，如图2-21所示本文选自Unity游戏开发技巧集锦。

图2-21  运行游戏，查看截图的效果