How can I test if my framebuffer object is rendering properly?

I'm using a framebuffer object with a color buffer attachment to do some per-pixel hit testing. I'd like to render it to the screen for debugging and testing but right now all I'm getting is a big white nothingness. I assume I have to send some render command similar to glSwapBuffers(), but as开发者_如何学运维 I'm only using one buffer I don't know what it would be swapping to. Is there an equivalent command for using just one buffer?

Here's my setup:

    // Store the real framebuffer
    glGetIntegerv(GL_FRAMEBUFFER_BINDING_OES, (GLint*) &regularFbo);
    // Generate an offscreen framebuffer/renderbuffer for rendering the hit detection polys
    // Create framebuffer
    glGenFramebuffersOES(1, &hitDetectionFbo);
    glBindFramebufferOES(GL_FRAMEBUFFER_OES, hitDetectionFbo);
    // Create colorbuffer
    glGenRenderbuffersOES(1, &colorBuffer);
    glBindRenderbufferOES(GL_RENDERBUFFER_OES, colorBuffer);
    // Create storage (RGBA) for color buffer
    glRenderbufferStorageOES(GL_RENDERBUFFER_OES, GL_RGBA8_OES, SCREEN_WIDTH, SCREEN_HEIGHT);
    // Attach color buffer to framebuffer
    glFramebufferRenderbufferOES(GL_FRAMEBUFFER_OES, GL_COLOR_ATTACHMENT0_OES, GL_RENDERBUFFER_OES, colorBuffer);
    glDisable(GL_DEPTH_TEST);
    glDepthMask(GL_FALSE);

This doesn't flag any glErrors but I'm clearly missing something, as nothing is appearing on screen after I switch over to my new FBO. The program will render just fine if I continue to use the original framebuffer (through a glBindFramebufferOES(GL_FRAMEBUFFER_OES, regularFbo) call).

Thanks for the help, -S

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On the iPhone platform, the only FBO that can be used directly as the backbuffer is the one that has a color buffer that has been allocated using:

[myEaglContext renderbufferStorage:GL_RENDERBUFFER fromDrawable: eaglLayer];

If you allocate a color buffer using glRenderbufferStorageOES, then it's a normal off-screen FBO, and the best way to make it show up the screen is to bind it to a texture and render a quad.