gluPerspective culling planes

I want to know how to determine the clipping planes for a perspective view. Say I load a bitmap. I want to only display it where it can be viewed. Another reason is so I can define them when I draw polygons OGL doesn't have to do any calculations on them, before it realizes it doesn't have to display it.

theres a good article about frustum culling on flipcode ( i think its this one)

also, i've written a cool demo which shows how to clips polygons against an arbitrary plane if your interested.

edit: link, url, whats the difference... ;)

yes i am. I knew you would be the one to respond :cool:
I am reading the article and am wondering, how do I replace this in C

Code:

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if(m_plane[p].SideOfPlane(vCorner[i]) == BEHIND) {

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Quote:

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Originally Posted by linuxdude

[...] how do I replace this in C

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well, this type of thing is well suited to OOP. If you want to use C and keep the same type of layout in the article, you could replace member functions of classes with function pointers in structs, then point the function pointers to wherever you define the functions.

Ill have to dig out the demo, it was an assignment from last year and i dont have it hear on my laptop. ill post it up when i have a chance.

okay I can wait
bu how would you actually get those values? Like the left clip plan, or any of them?

well, my demo is for clipping against arbitrary user defined planes. If you want to see how to extract the view frustum look at the "updateFrustum" function here
http://nehe.gamedev.net/data/lessons....asp?lesson=44