Why, after calling SetVideoMode as in the following, does nothing appear on my screen?

Question

I am trying to create an application that will need to use double buffering (for purpose of vsync). I am using SDL.NET. From what I understood, in order to have double buffering, I have to SetVideoMode with the opengl paremeter set to true.

Here's the code I'm using:

        Video.Initialize();

        Video.GLSetAttribute(OpenGLAttr.DoubleBuffer, 1);
        Video.GLSetAttribute(OpenGLAttr.SwapControl, 1);
        Video.GLSetAttribute(OpenGLAttr.RedSize, 8);
        Video.GLSetAttribute(OpenGLAttr.GreenSize, 8);
        Video.GLSetAttribute(OpenGLAttr.BlueSize, 8);
        Video.GLSetAttribute(OpenGLAttr.DepthSize, 16);

        Video.SetVideoMode(VideoInfo.ScreenWidth, VideoInfo.ScreenHeight, false, true, true, true);

If 4th parameter (bool opengl) is false, it works: a new fullscreen window is created and displayed (but I assume the OpenGLAttr's set above are meaningless in this case).

If 4th parameter is true, nothing happens. A new window gets created (at least, it appears in the list of open windows) but I cannot alt-tab into it and nothing appears on the screen.

What am I doing wrong?

Answer 1

Okay, I see that the problem was, I didn't output anything on the screen - doing Video.GLSwapBuffers() made the black screen appear.