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Fernando
12-18-2002, 11:27 AM
Hi guys. I'm a newbie with opengl and would like to know a way to copy my Front Buffer to the Back Buffer. Is it possible? or I can swap only from back to front?

Thank you!

Mazy
12-18-2002, 12:41 PM
take a look at

glDrawBuffer
glReadBuffer
glCopyPixels

Fernando
12-18-2002, 01:15 PM
Thank yoy Mazy.

But how I DO I use glCopyPixels? I've been trying to make it work the entire day, but til now, nothing....

Look how I'm doing:

glReadBuffer(GL_FRONT);
glDrawBufer(GL_BACK);
glRasterPos3f(0.0f, 0.0f, 0.0f);
glCopyPixels(10, 10, 50, 50, GL_DEPTH);
glCopyPixels(10, 10, 50, 50, GL_COLOR);
glDrawBufer(GL_BACK);
glReadBuffer(GL_BACK);

I don't know why... but it don't work!!


Help me please!

Thank you
Fernando.

[This message has been edited by Fernando (edited 12-18-2002).]

Bob
12-18-2002, 01:25 PM
Make sure the raster position is actually where you want it. Draw a single point at the raster position and see if it appears where you want it. If it doesn't, maybe the raster position is outside the window, which makes it invalid.

Fernando
12-18-2002, 01:48 PM
Yeah!!!

I was giving the a wrong value for the Z axis.

Now I'm using glRasterPos3f(0.0f, 0.0f, -1.0f) and there's a black box appearing on the center of the screen isntead of the front buffer....

Do you have any hints?

Thank you
fernando

Bob
12-18-2002, 02:44 PM
All I can say right now is that something is wrong, but that's obvious. You have to provide more information, preferably code (only relevant pieces).