I did not found the specification but I found the GL state diagram and...yes...the culling is performed after screen projection.
Now I know why GL, before HW acceleration, was so crappy [smile]
backface culling
Quote:Original post by blizzard999
Today we use OpenGL, DirectX and even pixel and fragment shaders so we have forgot the ancient art [smile]
don't fret, here you go.
http://www.devmaster.net/articles/software-rendering/part1.php
http://www.icarusindie.com/DoItYourSelf/rtsr/ <-- this one is awesome
Quote:Original post by blizzard999
I did not found the specification but I found the GL state diagram and...yes...the culling is performed after screen projection.
Now I know why GL, before HW acceleration, was so crappy [smile]
I don't know how one can not find the specification. A Google for, in my oppinion a pretty obvious search phrase, opengl specification returns, as first link, the place where you can download it. And on, in my oppinion an obvious place to look, opengl.orghas a direct link in the left menu on the front page.
Anyway, now I have given you two ways of getting it, so now you know where it is [wink]
Quote:Original post by Brother Bob
I don't know how one can not find the specification. A Google for, in my oppinion a pretty obvious search phrase, opengl specification returns, as first link, the place where you can download it. And on, in my oppinion an obvious place to look, opengl.orghas a direct link in the left menu on the front page.
Anyway, now I have given you two ways of getting it, so now you know where it is [wink]
[headshake]
I'm sorry...obviously I found the specification as well as the state diagram (they are on the same page at gl.org !)
What I've not found is the specification about the backface culling (probably with the new version it's no more in the section 2.13 as mikeman reported...)
No problem because if you follow the pipeline on the state diagram you see where backface culling is.
Quote:Original post by blizzard999
I'm sorry...obviously I found the specification as well as the state diagram (they are on the same page at gl.org !)
What I've not found is the specification about the backface culling (probably with the new version it's no more in the section 2.13 as mikeman reported...)
If that's what you meant, then I'm sorry for the misunderstanding. If you still want to read about it though, it's around equation (2.6) on page 63 in the OpenGL 2.0 specification. That particular part is about coloring with two sided lighting, where you need to determine what side is visible (to choose front or back material properties). That is about determining whether the back or front is visible, and that is what backface culling in OpenGL is about.
Quote:Original post by Brother Bob
If that's what you meant, then I'm sorry for the misunderstanding. If you still want to read about it though, it's around equation (2.6) on page 63 in the OpenGL 2.0 specification. That particular part is about coloring with two sided lighting, where you need to determine what side is visible (to choose front or back material properties). That is about determining whether the back or front is visible, and that is what backface culling in OpenGL is about.
Thanks
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