Unity | 部分区域*截图

一、固定区域截屏：

Unity三种截屏方法

二、*截图

using System.Collections;
using UnityEngine;

///挂在摄像机上
///如果要截图UI，需将Canvas的RenderMode设置为Screen Space-Camera，并将Render Camera设置为挂该脚本的摄像机

public class Capture : MonoBehaviour {
    public Color rColor = Color.green;//截图框颜色
    public Vector3 start = Vector3.zero;//开始位置
    public Vector3 end = Vector3.zero;//结束位置
    public Material rMat = null;//截图框材质，shader为"UI/Default"即可
    public bool drawFlag = false;//是否开始截图
    private Rect rect;//截图区域
    private Texture2D cutImage;//图片
    byte[] bytes;//图片byte
  
    void Update()
    {
        //按下鼠标左键开始截图
        if (Input.GetMouseButtonDown(0) && SecondPageManager._instance. ToCapture)
        {
            SecondPageManager._instance.CapturePanel.SetActive(false);
            drawFlag = true;
            start = Input.mousePosition;
        }
        //抬起鼠标左键结束截图
        if (Input.GetMouseButtonUp(0) && SecondPageManager._instance.ToCapture && drawFlag)
        {
            SecondPageManager._instance.ToCapture = false;
            drawFlag = false;
            StartCoroutine(CutImage());
        }
        //点击鼠标右键取消截图
        if (Input.GetMouseButtonDown(1) && SecondPageManager._instance.ToCapture)
        {
            SecondPageManager._instance.CapturePanel.transform.parent.gameObject.SetActive(false);
            SecondPageManager._instance.CapturePanel.SetActive(false);
            SecondPageManager._instance.ToCapture = false;
            drawFlag = false;
        }
    }
    //绘制框选  
    void OnPostRender()
    { 
        if (drawFlag)
        {
            end = Input.mousePosition;//鼠标当前位置  
            GL.PushMatrix();//保存摄像机变换矩阵  
            if (!rMat)
                return;
            rMat.SetPass(0);
            GL.LoadPixelMatrix();//设置用屏幕坐标绘图  
            GL.Begin(GL.QUADS);
            GL.Color(new Color(rColor.r, rColor.g, rColor.b, 0.2f));//设置颜色和透明度，方框内部透明  
            GL.Vertex3(start.x, start.y, 0);
            GL.Vertex3(end.x, start.y, 0);
            GL.Vertex3(end.x, end.y, 0);
            GL.Vertex3(start.x, end.y, 0);
            GL.End();
            GL.Begin(GL.LINES);
            GL.Color(rColor);//设置方框的边框颜色 边框不透明  
            GL.Vertex3(start.x, start.y, 0);
            GL.Vertex3(end.x, start.y, 0);
            GL.Vertex3(end.x, start.y, 0);
            GL.Vertex3(end.x, end.y, 0);
            GL.Vertex3(end.x, end.y, 0);
            GL.Vertex3(start.x, end.y, 0);
            GL.Vertex3(start.x, end.y, 0);
            GL.Vertex3(start.x, start.y, 0);
            GL.End();
            GL.PopMatrix();//恢复摄像机投影矩阵  
        }
    }
    IEnumerator CutImage()
    {

        string date = System.DateTime.Now.ToString("yyyyMMddHHmmss");
        //图片大小    
        if (end.x > start.x&& start.y > end.y)
        {
            cutImage = new Texture2D((int)(end.x - start.x), (int)(start.y - end.y), TextureFormat.RGB24, true);
            //坐标左下角为(0,0)点
            rect = new Rect((int)start.x,
                Screen.height - (int)(Screen.height - end.y), 
                (int)(end.x - start.x),
                (int)(start.y - end.y));
            yield return new WaitForEndOfFrame();
            cutImage.ReadPixels(rect, 0, 0, false);
            cutImage.Apply();
            yield return cutImage;
            bytes = cutImage.EncodeToPNG();
            //保存截图    
            //File.WriteAllBytes("D:/CutImage" + date + ".png", bytes);
            //公式识别
            StartCoroutine(FormulaRecognize._instance.OCRIdentify(bytes));
        }
        else
        {
            StartCoroutine(FormulaRecognize._instance.OCRIdentify(null));
            Debug.Log("请按照左上角到右下角的方式截图"); 
        }
    }
}