Technical solution to eliminate desync in single-player sessions

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MrMisterMissedHer wrote:

Everyone actually concerned about FP determinism (actual programmers), if you are uninformed, lacking the knowledge, please ignore the posts about FP determinism and inform yourself.

http://randomascii.wordpress.com/2013/07/16/floating-point-determinism/

Some of the crap I've read in this thread is hilarious.

Excellent article.
In my mind qwave's CURRENT plan(as opposed to the many many prior iterations) could be made to work with extensive code, nearly a complete recode. There are several solutions i have imagined to make it viable(including the fp issue), yet am keeping them secret. Because as iv said in the past, this proposal throws many aspects of security out the window. It also requires a large investment of resources for a very limited (and not guaranteed) payoff.

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MrMisterMissedHer wrote:

Everyone actually concerned about FP determinism (actual programmers), if you are uninformed, lacking the knowledge, please ignore the posts about FP determinism and inform yourself.

http://randomascii.wordpress.com/2013/07/16/floating-point-determinism/

Some of the crap I've read in this thread is hilarious.

This has already been discussed and understood. It's nothing new. And i'll quote something from the article:

"If you can control these factors – some are easy to control and some may involve a lot of work – then floating-point math can be deterministic, and indeed many games have been shipped based on this. Then you just need to make sure that everything else is deterministic and you are well on your way to an extremely efficient replay and networking mechanism."

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MrMisterMissedHer wrote:

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LogoOnPoE wrote:

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MrMisterMissedHer wrote:

Everyone actually concerned about FP determinism (actual programmers), if you are uninformed, lacking the knowledge, please ignore the posts about FP determinism and inform yourself.

http://randomascii.wordpress.com/2013/07/16/floating-point-determinism/

Some of the crap I've read in this thread is hilarious.

This has already been discussed and understood. It's nothing new. And i'll quote something from the article:

"If you can control these factors – some are easy to control and some may involve a lot of work – then floating-point math can be deterministic, and indeed many games have been shipped based on this. Then you just need to make sure that everything else is deterministic and you are well on your way to an extremely efficient replay and networking mechanism."

Excuse me for posting it again, I honestly couldn't read through this whole thread and some of the more recent posts suggest a rather poor understanding of the issue.

No problem, and some early posts by qwave do indicate the lack of knowledge, but it was sorted out during the discussion.

Edit: though i'm not sure this exact article was posted, some others concerning the issue were. So I guess thanks for the article, and I guess I worded my response a bit aggressively.

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LogoOnPoE wrote:

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MrMisterMissedHer wrote:

Everyone actually concerned about FP determinism (actual programmers), if you are uninformed, lacking the knowledge, please ignore the posts about FP determinism and inform yourself.

http://randomascii.wordpress.com/2013/07/16/floating-point-determinism/

Some of the crap I've read in this thread is hilarious.

This has already been discussed and understood. It's nothing new. And i'll quote something from the article:

"If you can control these factors – some are easy to control and some may involve a lot of work – then floating-point math can be deterministic, and indeed many games have been shipped based on this. Then you just need to make sure that everything else is deterministic and you are well on your way to an extremely efficient replay and networking mechanism."

I would reread the summary page. Saying FP is deterministic is like saying that poverty can be "solved".

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deteego wrote:

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LogoOnPoE wrote:

This has already been discussed and understood. It's nothing new. And i'll quote something from the article:

"If you can control these factors – some are easy to control and some may involve a lot of work – then floating-point math can be deterministic, and indeed many games have been shipped based on this. Then you just need to make sure that everything else is deterministic and you are well on your way to an extremely efficient replay and networking mechanism."

I would reread the summary page. Saying FP is deterministic is like saying that poverty can be "solved".

"and indeed many games have been shipped based on this"

Does that mean that poverty has been solved many times?

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LogoOnPoE wrote:

Does that mean that poverty has been solved many times?

No it means that poverty has only been solved for certain countries, at certain times. Read the article, once, twice, and then three times.

As has been stated numerous times, whether FP determinism is possible depends on a huge number of factors, and only one of those factors needs to be out of PoE's control to throw the whole concept of FP determinism out of the window.

It can be anything from what language they are using, or the practical limits to ensure compilers produce same results across their servers and clients, to many other things.

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deteego wrote:

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LogoOnPoE wrote:

Does that mean that poverty has been solved many times?

No it means that poverty has only been solved for certain countries, at certain times. Read the article, once, twice, and then three times.

As has been stated numerous times, whether FP determinism is possible depends on a huge number of factors, and only one of those factors needs to be out of PoE's control to throw the whole concept of FP determinism out of the window.

It can be anything from what language they are using, or the practical limits to ensure compilers produce same results across their servers and clients, to many other things.

Yes, it depends on many factors and requires work, is that your point?

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LogoOnPoE wrote:

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deteego wrote:

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LogoOnPoE wrote:

Does that mean that poverty has been solved many times?

No it means that poverty has only been solved for certain countries, at certain times. Read the article, once, twice, and then three times.

As has been stated numerous times, whether FP determinism is possible depends on a huge number of factors, and only one of those factors needs to be out of PoE's control to throw the whole concept of FP determinism out of the window.

It can be anything from what language they are using, or the practical limits to ensure compilers produce same results across their servers and clients, to many other things.

Yes, it depends on many factors and requires work, is that your point?

My point is its not a black and white possible/impossible, its about how practical it is, and I have always said that for PoE specifically, doing deterministic FP is practically unfeasible, that doesn't mean its impossible, it just means it most likely won't ever be done due to the engineering effort required

The fact that some very few rare games have been shipped with FP determinism is irrelevant, because those games don't have the same environment, or same factors, as PoE has.

If PoE for example, runs their servers on different OS's with different CPU's, you can pretty much forget about any FP determinism, and thats only one factor. As has been explained in the article, every single factor has to be controlled for FP to be deterministic, only one factor needs to be out of place, than your FP is not deterministic

And odds are, if it was practically feasible, it would have been done by now