Display lists and contexts
Author
I am working on a base class method that will start up a gl window. Everything is working fine, except when I run two instances of it. I am creating a display list of an object based on random numbers, and rotating it. Both windows show the same object. I checked the rendering context before creating the list and they are two distinct contexts. The appropriate context is set before the display loop is called. The display list numbers are the same however. Is that what is supposed to happen? Any ideas?
Thanks!
Author
Well, I figured out what was going on, but it is rather strange. Before starting the display loop I set the appropriate context, initialize OpenGL, seed the random number generator with the time, then create my display list. Apparently, the random numbers for both instances were the exact same. I didn''t think this should happen since I am seeding with the time:
srand(time(NULL));
Seeding the generator just once solved the problem. I suppose the seed must have been the same for each initialization, but since its done with time(), I would not expect that. Any one more familiar with the workings of these functions?
srand(time(NULL));
Seeding the generator just once solved the problem. I suppose the seed must have been the same for each initialization, but since its done with time(), I would not expect that. Any one more familiar with the workings of these functions?
How close together are these seed calls? The time() call only has a granularity of 1 second, IIRC.
Author
That''s what the problem was. I was performing one initialization, then reseeding the generator within the same second. I should probable use timeGetTime().
The elasped time is probably insignificant. Anyways, excepting a very few select circumstances, you should only ever call srand once per application.
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The Phoenix shall arise from the ashes... ThunderHawk -- ¦þ
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The Phoenix shall arise from the ashes... ThunderHawk -- ¦þ
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