Clearing Depth Buffer in FBO

I have an FBO with a couple of color attachments and a depth attachment. My question is, when I call glClear(GL_DEPTH_BUFFER_BIT) how do I know if it’s the depth renderbuffer attached to the FBO that’s being cleared? (a.k.a. How do I know it’s not the default window depth buffer being cleared?)

I’ve been trying to write a small test program, but so far no luck in figuring out the answer.

When your FBO is bound, glClear will clear its depth-buffer. If no FBO is bound, the window depth buffer is cleared.

You unbind an FBO (and thus make the window buffers current) by calling glBindFramebuffer with the FBO index 0.


Okay, great. That’s what I thought. I was just confused by an example program I had found that was calling glClear before the FBO was bound.