Random number generator

[mentor]

I need to generate a random (really random, not pseudo-random) number at the very beginning of the program. I need to initialize the position of a certain sprite and this position has to be different each time the game starts. rand() itself generates the same position every time I start the game, so I need to seed it using srand(). On Windows I would use time(NULL) as a parameter here, but PSY-Q doesn't provide us with time() function (which is fully understandable). I searched the docs for some replacement of time(), but I haven't found anything. It seems like there's no way I could get PS1 system time or anything similar to it. Psymake doesn't recognize rdtsc()... And so I'm actually out of ideas. srand() needs some initial starting point as a seed and this seed also needs to be different each time. Therefore, how to seed srand(), so rand() would generate random number, different each time the program starts?

[Administrator]

I need to generate a random (really random, not pseudo-random) number at the very beginning of the program. I need to initialize the position of a certain sprite and this position has to be different each time the game starts. rand() itself generates the same position every time I start the game, so I need to seed it using srand(). On Windows I would use time(NULL) as a parameter here, but PSY-Q doesn't provide us with time() function (which is fully understandable). I searched the docs for some replacement of time(), but I haven't found anything. It seems like there's no way I could get PS1 system time or anything similar to it. Psymake doesn't recognize rdtsc()... And so I'm actually out of ideas. srand() needs some initial starting point as a seed and this seed also needs to be different each time. Therefore, how to seed srand(), so rand() would generate random number, different each time the program starts?

Use the system root counter as a randomiser base and parse it through a custom algorithm (function).

Here is a small example of a random function:

Code: Select all

///////////////////////////////////////////////////////////
// Random Number Generator (global)
///////////////////////////////////////////////////////////
int Random(int max)
{
	RAN = (rand()%max);
	return 0;
}

or

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///////////////////////////////////////////////////////////
// Random Number Generator (local)
///////////////////////////////////////////////////////////
int Random(int max)
{
	int RAN = 0;
	RAN = (rand()%max);
	return RAN;
}

All you need to do is make it use an algo based off of the root counter.
'max' is the maximum amount you would like to return. So if you parse 10, you will get numbers 1 through 10.

[mentor]

Thanks for your answer. If I understand you correctly, I need to set srand() parameter to GetRCnt(RCntCNT1)), like this:

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srand(GetRCnt(RCntCNT1));

But before I can use GetRCnt() function I need to set RCntCNT1 mode to RCntMdNOINTR and this can be done by calling SetRCnt:

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SetRCnt(RCntCNT1,0,RCntMdNOINTR);

I don't really know what second parameter here should be. 0? Something else? Is this way of setting seed even correct?