帮助c中的opengl或opentk＃

Question

我正在用OpenTK工具在c＃中使用OpenGL。

我的问题是：首先，我们想要在glwindows中绘制一些带有线条的形状，我们开始绘制线条，使用按钮MouseDown事件并使用键（e）完成它，当我们完成绘制线时，想要画出新的线条，windowsframe（ColorBufferBit）会清除，我不知道我必须做什么？

更多的解释，我必须说的是，当我们画线，我们称之为
GL.Clear(ClearBufferMask.ColorBufferBit | ClearBufferMask.DepthBufferBit); ，当我们finishid它，我们将要darwing新的生产线，强制，我必须调用
GL.Clear(ClearBufferMask.AccumBufferBit | ClearBufferMask.DepthBufferBit);
什么是必须我做？ 这里是代码

using System; 
using OpenTK; 
using OpenTK.Graphics; 
using OpenTK.Graphics.OpenGL; 
using OpenTK.Audio; 
using OpenTK.Audio.OpenAL; 
using OpenTK.Input; 
using System.Drawing; 
using System.Drawing.Imaging; 

namespace FarmApp 
{ 
class openGLfarm : GameWindow 
{ 
    bool flage, chechFirst; 
    float XMouseBegin_first, YMouseBegin_first; 
    //----------------------------- 
    public openGLfarm(GraphicsMode mode) 
     : base(700, 700, GraphicsMode.Default, "O Sample") 
    { 
     VSync = VSyncMode.On; 
     chechFirst = true; 
     Mouse.ButtonDown += new EventHandler<MouseButtonEventArgs>(Mouse_ButtonDown); 
     Mouse.ButtonUp += new EventHandler<MouseButtonEventArgs>(Mouse_ButtonUp); 
     Mouse.Move += new EventHandler<MouseMoveEventArgs>(Mouse_Move); 

     Mouse.ButtonDown += new EventHandler<MouseButtonEventArgs>(Mouse_ButtonDown); 
     Mouse.ButtonUp += new EventHandler<MouseButtonEventArgs>(Mouse_ButtonUp); 
     Mouse.Move += new EventHandler<MouseMoveEventArgs>(Mouse_Move); 


    } 
    //------------------------------- 
     public openGLfarm() 
    { 
     // TODO: Complete member initialization 
    } 


    void Mouse_Move(object sender, MouseMoveEventArgs e) 
    { 
     // Now use mouse_delta to move the camera 
    } 

    void Mouse_ButtonUp(object sender, MouseButtonEventArgs e) 
    { 
     switch (e.Button) 
     { 
      case MouseButton.Left: 
       { 
        flage = true; 
        if (chechFirst) 
        { 
         chechFirst = false; 
         XMouseBegin_first = Mouse.X; 
         YMouseBegin_first = Mouse.Y; 

        } 
        break; 
       } 
      case MouseButton.Middle: 
       ///camera_mode = ECameraMode.CAMERA_DOLLY; 
       break; 
      case MouseButton.Right: 
       //camera_mode = ECameraMode.CAMERA_ORBIT; 
       break; 
     } 

    } 

    void Mouse_ButtonDown(object sender, MouseButtonEventArgs e) 
    { 
     switch (e.Button) 
     { 
      case MouseButton.Left: 
       { 
        break; 
       } 
      case MouseButton.Middle: 
       ///camera_mode = ECameraMode.CAMERA_DOLLY; 
       break; 
      case MouseButton.Right: 
       //camera_mode = ECameraMode.CAMERA_ORBIT; 
       break; 
     } 
    } 

    protected override void OnLoad(EventArgs e) 
    { 
     base.OnLoad(e); 
    } 

    protected override void OnResize(EventArgs e) 
    { 
     base.OnResize(e); 

    } 

    protected override void OnUpdateFrame(FrameEventArgs e) 
    { 
     base.OnUpdateFrame(e); 
     if (Keyboard[Key.Escape]) 
      Exit(); 
     if (Keyboard[Key.E]) 
     { 
      flage = false; 
      chechFirst = true; 

     } 
    } 



    void table(float count) 
    { 
     float x, y; 
     GL.Color4(Color4.Wheat); 

     float z = (2f)/(count); 
     x = -1; 
     y = -1; 
     for (double i = 0; i < count; i++) 
     { 
      GL.Begin(BeginMode.Lines); 

      GL.Vertex2(x + (z), -1); 
      GL.Vertex2(x + (z), 1); 

      GL.End(); 
      x = x + (z); 
     } 

     for (double i = 0; i < count; i++) 
     { 
      GL.Begin(BeginMode.Lines); 

      GL.Vertex2(-1, y + (z)); 
      GL.Vertex2(1, y + (z)); 

      GL.End(); 
      y = y + (z); 
     } 


    } 
    public void DrawLine(float Xbegin, float Ybegin, float Xend, float Yend) 
    { 
     GL.Begin(BeginMode.Lines); 
     GL.Vertex2(Xbegin, Ybegin); 
     GL.Vertex2(Xend, Yend); 
     GL.End(); 

    } 
    protected override void OnRenderFrame(FrameEventArgs e) 
    { 
     //base.OnRenderFrame(e); 
     if (chechFirst) 
      GL.Clear(ClearBufferMask.AccumBufferBit | ClearBufferMask.DepthBufferBit); 

     else 
      GL.Clear(ClearBufferMask.ColorBufferBit | ClearBufferMask.DepthBufferBit); 
     GL.MatrixMode(MatrixMode.Modelview); 
     GL.LoadIdentity(); 
     table(Form1.co); 
     if (flage) 
     { 
      //flage = false; 
      DrawLine((XMouseBegin_first/350f - 1f), -(YMouseBegin_first/350f - 1f), (Mouse.X/350f - 1f), -(Mouse.Y/350f - 1f)); 
     } 
     SwapBuffers(); 
    } 
} 

}

Answer 1

你可以福尔例如创建Vector2的数组去保存它的起点和终点。然后在绘制线条的函数中绘制并绘制所有这些线条。