while on the subject of linked lists, why is it that all of the tutorials (and my C++ book) never delete any of the memory they have created?!
Is it just bad programming or can you leave it for windows to clean up? ----- Original Message ----- From: "Persuter" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Friday, June 28, 2002 5:20 AM Subject: RE: [hlcoders] Particle System > Jim: yeah, that's what I said earlier. The benefit of using arrays lies > in the fact that they're sequential and initialized early, so no memory > allocation time. But as you so correctly pointed out, the problem of > figuring out the most efficient use of space within the array is not > simple. > > Anyway, I think we're all forgetting the 80-20 rule here. 80% of > processing time is taken up by 20% of the program. I seriously doubt, > based on my observations, that at reasonable amounts of particles, a > carefully-programmed particle system using linked lists is in that 20%. > > Also, consider this. If you initialize a long linked list at the > beginning of the program and create all the individual rendering lists > from that, you get most of the advantages of sequentiality without the > staticness of arrays, since malloc or new will allocate sequential > memory. You can grow the list at any time, and you can shrink it within > the program if memory limits start to be reached. > > Persuter > > > -----Original Message----- > > From: [EMAIL PROTECTED] [mailto:hlcoders- > > [EMAIL PROTECTED]] On Behalf Of Jim Hunter > > Sent: Thursday, June 27, 2002 11:28 PM > > To: [EMAIL PROTECTED] > > Subject: Re: [hlcoders] Particle System > > > > > Sure, having the ability to create a *variable* number of particles > is a > > > plus by using a linked list over an array. Why have 20,000 dormant > > > classes/structures taking up memory when you don't have to? How > about > > > allocating new particles? Are you supposed to scan through the > entire > > array > > > each time you wish to create a new particle to find that indexes 919 > and > > > 9294-12300 are free? By using a linked list, you can simply store a > > pointer > > > to the last particle and then add on to it as necessary. > > > > Forgive my ignorance, but aren't you just shifting that burden (of > finding > > empty space to store a new particle) from your own code to the heap > > manager? > > I have no idea which would be more efficient, but either way, > *something* > > has got to look for storage space and determine that it's unused, and > > reclaim space that is no longer used. I would bet the performance > would > > be > > close to equal; anyone know if a formal analysis of such a problem has > > been > > done? Just curious. > > > > Jim > > > > _______________________________________________ > > To unsubscribe, edit your list preferences, or view the list archives, > > please visit: > > http://list.valvesoftware.com/mailman/listinfo/hlcoders > > _______________________________________________ > To unsubscribe, edit your list preferences, or view the list archives, please visit: > http://list.valvesoftware.com/mailman/listinfo/hlcoders > > _______________________________________________ To unsubscribe, edit your list preferences, or view the list archives, please visit: http://list.valvesoftware.com/mailman/listinfo/hlcoders
