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Phobeus

glList and modern PCs

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Phobeus    122
Hi Guys, I just throw a view on lesson 12 and everything seems to work fine on my system here. Only I would swear that the autor is talking about a speed win using glLists, ain''t I right? I cannot detect anything on that? I draw several cubes (20*20 as field) using diffrent colors, once as a list and once as a normal vertex call. Both seems to be totally equal and are arround a rock solid 48 FPS. Did I make anything wrong, or can you detect this speed ups only on older systems (currently using P4 1,7 GhZ, Geforce2 MX 64 and 768 MB RAM). Or better asked... how big is the speed win I can expect? ThanXs in Advise! Phobeus

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Guest Anonymous Poster   
Guest Anonymous Poster
quote:
Original post by Phobeus
Hi Guys,

I just throw a view on lesson 12 and everything seems to work fine on my system here. Only I would swear that the autor is talking about a speed win using glLists, ain''t I right? I cannot detect anything on that? I draw several cubes (20*20 as field) using diffrent colors, once as a list and once as a normal vertex call. Both seems to be totally equal and are arround a rock solid 48 FPS.

Did I make anything wrong, or can you detect this speed ups only on older systems (currently using P4 1,7 GhZ, Geforce2 MX 64 and 768 MB RAM). Or better asked... how big is the speed win I can expect?




Are you drawing one list many times, or many cubes in one list?

Also, have you turned vsync off?

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Phobeus    122
No there''s only one cube in the list and I draw the list several times.

V-Sync isn''t deactivate as far as I would guess. How can I do this? Sorry, i am starting with OpenGL and comes from D3D

thx,
Phobeus

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miles vignol    122
As I understand it, lists are the fasted way to draw -- unless they are very small (in the amount of geometry they represent). For example, it''s actually slower to draw a single quad as a list. I dunno where the trade-off occurs, tho. Maybe around a hundred polys or so?

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Yann L    1802
Display lists are indeed very fast (though VAR beats everything) but there is a point, where the list overhead is larger than the potential speedup. The trade-off point is highly hardware and driver dependent. But I would not use a DL for anything less than 250 faces.

Try to put your whole cube-field into a single DL, and you''ll notice a big speedup. And turn off vsync, otherwise your timing will completely screw up.

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Phobeus    122
Hmm... yes, i guessed something like that. In fact is it right to say, that i won''t get any loses for using a DL (not slower than a "normal" cube), right?

And please... don''t let me stand alone with the v-sync How can i use (even better with checking) it?

thx,
Phobeus



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quote:
Original post by Phobeus
Hmm... yes, i guessed something like that. In fact is it right to say, that i won''t get any loses for using a DL (not slower than a "normal" cube), right?



You might. Depends on the driver.

quote:

And please... don''t let me stand alone with the v-sync How can i use (even better with checking) it?



There''s an extension for doing this in your program, but there''s usually a place you can turn this off in your display driver''s perferences.

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