Flip entire framebuffer upside down?

Subject says what I need to do…systematically do a vertical flip of everything in the framebuffer right before it is displayed onscreen.

Flipping just the geometry (glPixelZoom, etc.) will not work in this application (don’t ask).

OK, I won’t ask


or similar, possibly???


Doesn’t work.

turn the monitor upside down


actually, that’s exactly what i’m doing

Any other suggestions on how to do this without moving the monitor or standing on my head?

you could render to a texture or copy the framebuffer to a texture then draw a quad with that as its texture across the entire screen

Since you say you want a flip, not a rotate, I would guess glScalef(1.0, -1.0, 1.0) would be more appropriate. I wouldn’t put it in the projection matrix, though. You can mess up lighting/fog calculations. Do that before any “Camera” transformations like gluLookAt()

WHy not just swap the signs on the top/bottom parameters when you create your frustum?