OpenGL ES : Revealing underneath view

I am working on a sample in which I have placed two textures one above the other. What I want, whenever user moves his finger on the screen, underneath view should get revealed as he moves. Wiping out front view to reveal underneath view is what I am looking for.

I would like to know some of ideas/ thoughts to implement this feature using OpenGL ES. Any related pointer will be highly appreciated.

Thanks in advance.开发者_如何学Python

This does not sound performance-intensive so simple code can trump complicated tuned operations.

You don't need to use OpenGL. You can simply have two images - front and back - with the front supporting an alpha channel. Each time you get a hit or move, you clear a circular patch whereever the impact is for some certain radius or such.

And then queue-up a redraw. The redraw draws the two bitmaps, back first then front.

If possible, try to queue a redraw for just the the area where you have updated the front since the last draw.