how to render small texture on another texture?

Question

can anybody help me to render small texture on another texture. i.e I have one background image, when user touches on the screen it should draw small(circle or any object) on it.

can anybody suggest me good tutorial to starts with it?

Answer 1

It's called off-screen rendering. In OpenGL you perform normal rendering, but into another render target where you have bound texture which you want render to.

There's wiki documenting it very well, especially this section. It has example for both OpenGL ES1, ES2.

Answer 2

You can bind the background as a render target, and then render the circle onto it. And the next time you want to render a circle onto it, you bind it, but don't clear the colorbuffer, just draw the circle again.