Flip entire framebuffer upside down?

[Jared@ETC]

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).

[Rob Fletcher]

OK, I won't ask

glMatrixMode(GL_PROJECTION);
glRotatef(180.0,0.0,0.0,1.0);
glMatrixMode(GL_MODELVIEW);

or similar, possibly???

R.

[Jared@ETC]

Doesn't work.

[coredump]

turn the monitor upside down

b

[Jared@ETC]

actually, that's exactly what i'm doing http://www.opengl.org/discussion_boards/ubb/wink.gif

[Jared@ETC]

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

[chowe6685]

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

[Deiussum]

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()

[Omaha]

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