// method called when Render is requested via Invalidate private void glControl1_Render(object sender, OpenGL.GlControlEventArgs e) { Control senderControl = (Control)sender; Gl.Viewport(0, 0, senderControl.ClientSize.Width, senderControl.ClientSize.Height); Gl.Clear(ClearBufferMask.ColorBufferBit | ClearBufferMask.DepthBufferBit); GraphicsHandler.SetDrawingColor1(); GcodeHandler.RedrawFullPicture(); GraphicsHandler.SetDrawingColor2(); GcodeHandler.RedrawCompletedPicture(); }