Could someone explain:

dogscoff · #1 May 9th, 2001, 12:31 PM

Does anyone recall Frontier: Elite II? That came on 2x 1meg floppies and the map size on there was ridiculous. There were (literally) millions and millions of systems.

Once I jammed my cursor keys down on the system map and went away for a while. When I got back it had reached grid -1124, 295 or something, and it had still only moved a few pixels on the (full screen) galactic map. To put that to scale, each grid reference had maybe half a dozen 3D systems in. Only the nearest few hundred grid references actually stored system information other than the word "unexplored" but the amount of information was mind blowing.

When I reloaded the game another time and checked back, though, the system data was exactly the same (even at -1124, 295), so if it was generating the systems dynamically, it wasn't doing it randomly. It *must* have been generated on the fly by some kind of fractal routine. Veeeery clever. Shame the rest of the game was so buggy.

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"Pinky, are you pondering what I'm pondering?"
"Uh, I think so Brain, but how are we gonna teach a goat to dance with flippers on? "

Askan Nightbringer · #2 May 10th, 2001, 01:03 AM

The Elite guys did randomly create their map. But they stored the 'seed' used to randomly create the map so when you loaded up a game you always got the same result.

This is because random numbers on computers aren't really random. There is just a huge lookup table full of numbers and each one comes out in order. The 'seed' is what is used to work out where you start in that table.

If you use the same 'seed' you'll always get the same numbers in the same order.

ie. If seed = 24
First 5 random numbers is
4 11 3 6 3

So I don't have to store 4,11,3,6,3 all I have to store is the seed (24 in this case).

The original Elite universe was stored in something like 4 bytes of data (which is 32 1's or 0's ). They just had table to look up desriptions based on verbs and nouns. (I guess its the lookup tables that took up all the space)

ie. The Gelbars are known for their fanatical love of sitcoms.

Well thats my bit of completely useless trivia for the week.

Askan

dogscoff · #3 May 9th, 2001, 02:55 PM

Interesting. Not much good for SE though, sinc once the map is generated you *still* have the problem of how to manipulate it all in memory.

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"Pinky, are you pondering what I'm pondering?"
"Uh, I think so Brain, but how are we gonna teach a goat to dance with flippers on? "

Krakenup · #4 May 9th, 2001, 03:20 PM

quote:
Originally posted by askan:
This is because random numbers on computers aren't really random. There is just a huge lookup table full of numbers and each one comes out in order. The 'seed' is what is used to work out where you start in that table.

If you use the same 'seed' you'll always get the same numbers in the same order.

Usually, it's not really a table. Most Random Number Generators perform a series of mathematical operations on the seed, generating a "random" number and a new seed. So if you start with the same seed, as askan said, you get the same series of random numbers. Tables of random numbers exist, but, if you are using billions of them, it's a lot easier to generate them on the fly.

zen. · #5 May 9th, 2001, 08:17 PM

LemmyM:
AFAIK, the AI would behave the same, because it works on a case-by-case basis and not as a 'look at the empire as a whole' thing. But I think I know what you mean...the AI on one Quadrant map wouldn't know that it also existed on the other Quadrant map...they'd be the equivalent of Neutrals stranded in their own system.

Either way, thinking about it, I have enough problems securing 250 systems as is.

Try conquering without glassing worlds...it rilly drags it out and forces you to keep supply lines!

zen

DirectorTsaarx · #6 May 10th, 2001, 05:41 PM

quote:
Originally posted by zenbudo:
Either way, thinking about it, I have enough problems securing 250 systems as is. Try conquering without glassing worlds...it rilly drags it out and forces you to keep supply lines!

zen

Or you at least end up with the same "problem" they had in Ender's Game: the ships available to destroy/take over the enemy homeworld were old, obsolete ships that had been launched decades earlier. I'm having a similar problem in my current game (which I may abandon since it's v1.30 & I'm skirting the boundary of MEE). I've stopped colonizing outside my current boundaries; now I just cruise around and destroy the enemy. Fortunately, I have Quantum Reactors now, so supply is less of an issue; but I still have obsolete ships trying to take on the enemy...

Omega · #7 May 13th, 2001, 05:57 AM

quote:
Originally posted by dogscoff:
Interesting. Not much good for SE though, sinc once the map is generated you *still* have the problem of how to manipulate it all in memory.

You don't store anything in memory. You store everything in a database. Your only limits are the limits of the database system. My unfinished 4X space game uses a database to allow thousands of systems and dozens of AI players. Alpha Centauri is supposed to be a database based game. The technology has existed for years.

Also, a short is always 16-bits in C. The size of an int is dependent on the compiler.