I'm trying to learn a little about OpenGL, so I'm making a simple 2D game (with OpenTK), and so far it's coming along well. I thought it would be fun to give it that, for lack of a better word, retropixelated look of games from the early nineties. I figured it would be an easy thing to do -- simply draw everything at half its normal size and scale up with no anti-aliasing.

But I can't find any resources on how to do this. I can set the min/mag filters of my textures to nearest and that works fine for my sprites, but I'm using lots of primitives and I'd like the effect to apply to them as well.

The one idea I had was to draw everything at half size, then somehow copy the render buffer to a texture, then render that texture full-size, but I don't know how to do that, and it seems like there must be a better way. Can anyone help me out?