Saving and restoring image in a view *without* using a nav controller?

Question

I'm writing an OpenGL app which draws trails/strokes by not clearing the frame buffer from frame to frame (it just lets everything accumulate on top of itself, which is what I want).

The app has a Settings screen. You access it by tapping a button. After you're done with the settings, it returns to the graphics.

Here's the problem: I can't figure out how to transition from the settings back to the graphics without losing what was in the frame buffer. The app is sort of a painting toy. You'd like to be able to paint, go to the settings, and then return to what you were doing without the screen clearing and deleting your work!

If I used a NavigationController all of this would be taken care of (I've tried it -- works perfectly!)

Problem is, I don't want the ugly, bulky nav bar thing on the top of my screen. But, you have to take the nav bar if you want the nav controller.

Any ideas?

Answer 1

Your solution is simple. Hide the navigation bar.

navController.navigationBar.hidden = YES;

See here:

UINavigationController without navigation bar?

Answer 2

Before you leave to go to the settings, save what's in the framebuffer with glReadPixels. When you return, load that data into a texture and draw it on the screen.