Unity使用GL绘制线条

public class Test : MonoBehaviour
{
//由于Camera在完成绘制后会清空屏幕，若此前调用GL接口，绘制内容会被清空。通常会在Camera的OnPostRender()或绘制对象的OnRenderXX()中。
    private void OnPostRender()
    {
        //DrawSingleLine();
        DrawMutilLine();
        //DrawScreenSingleLine();
    }

    void DrawMutilLine() {
        List<Vector3> posList = new List<Vector3>();
        posList.Add(new Vector3(0.3f, 0.6f, 0));
        posList.Add(new Vector3(1.2f, 1.8f, 0));
        posList.Add(new Vector3(0.6f, 2.4f, 0));
        posList.Add(new Vector3(1.5f, 2.7f, 0));

        if (posList.Count < 2) return;

        GL.Begin(GL.LINES);
        for (int i = 0; i < posList.Count - 1; i++) {
            GL.Vertex(posList[i]);
            GL.Vertex(posList[i + 1]);
        }
        GL.End();
    }

    void DrawSingleLine() {

        Vector3 start = Vector3.zero;
        Vector3 end = new Vector3(10, 10, 10);

        GL.Begin(GL.LINES);
        GL.Color(Color.red);
        GL.Vertex(start);
        GL.Vertex(end);
        GL.End();
    }

    void DrawScreenSingleLine()
    {
        Vector3 start = Vector3.zero;
        Vector3 end = new Vector3(0.2f, 0.7f, 0);

        GL.LoadOrtho(); //屏幕空间，圆心为屏幕左下角，屏幕区域{(0,1), (0,1)}
        GL.Begin(GL.LINES);
        GL.Color(Color.red);
        GL.Vertex(start);
        GL.Vertex(end);
        GL.End();
    }
}