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View Full Version : Flip entire framebuffer upside down?



Jared@ETC
07-25-2002, 06:29 AM
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).

ScottManDeath
07-25-2002, 08:35 AM
Hi

I would render it to a texture and then render a full screen quad with prober texture coordinates. You could either do a glCopySubTexImage or using the WGL_render_texture extension or perhaps the NV_texture_rectangle extension

Bye
ScottManDeath

davepermen
07-26-2002, 05:48 AM
if possible, you could render everything upside down as well.. depends on the exact problem, but possibly is a solution as well..

or turn your screen upside down.. http://www.opengl.org/discussion_boards/ubb/smile.gif

Mazy
07-27-2002, 02:12 AM
Scale the projection matrix with glScale(1,-1,1);

that might screw up some other calcs like fog, but as we cant ask you what its for, maybe that will help

AdrianD
07-27-2002, 05:36 AM
Originally posted by Mazy:
Scale the projection matrix with glScale(1,-1,1);

that might screw up some other calcs like fog, but as we cant ask you what its for, maybe that will help

this helps only, when you also reverse your backfaceculling function.

Bode
07-29-2002, 02:04 AM
I don't know if this solves your problem, but I just negate the FOV in gluPerspective(). Like so:
gluPerspective(-45.0, screenWidth/screenHeight, 1.0, 100.0);

Bode