using OpenGL;
Gl.Viewport(0, 0, (int)MainWindow.Width, (int)MainWindow.Height);
Gl.Clear(ClearBufferMask.ColorBufferBit);
Gl.MatrixMode(MatrixMode.Projection);
Gl.LoadIdentity();
Gl.Ortho(0.0, 1.0, 0.0, 1.0, 0.0, 1.0);