Switching to and from orthogonal projection

I’m currently working on an openGL project in which I have implemented a console…

I use orthogonal projection when rendering the console so that i can accurately place text and draw the console on a per pixel basis, but I dont use orthog when rendering my game world. So each frame (if the console is up) I need to switch to orthogonal projection to render it then switch back to render the world, I’d like to know the quickest way of doing so.

Currently I use quite a few lines of code to switch OUT of orthog (to ‘perspective’ projection?) because I set up the view area and fov all over again, which I’m sure is unnecessary.


the usual strategy is to use glPushMatrix() and glPopMatrix to store the perspective projection while you render in ortho. At least thats what I usually do. I doubt however that the switch between ortho and perspective is likely to be a bottleneck in your program.

I think I tried push & pop matrix but something went all funny with the perspective mode, maybe I just need to experiment more