Could someone explain:
 

Could someone explain why we can not have over 255 systems? What exactly happens when you exceed this number and why?

I want to have a game with up wards of 350 systems in it, but am fearfull that will cause problems, and I do not know why. Your help is appreciated as always.


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"We've made too many compromises already, too many retreats! They invade our space and we fall back -- they assimilate entire worlds and we fall back! Not again! The line must be drawn here -- this far, no further! And I will make them pay for what they've done!" -- Patrick Stewart as Captain Picard
UCP/TCO Ship Yards

Re: Could someone explain:
 

This came up a week or two ago and my guess it has something to with an 8 bit variable being somehow associated with storing info about the systems. Possibly some sort of bitmap relating to an internal bookkeeping variable, possibly the ID number of the system used by the game. You could try to add more, but my guess it is that it won't generate more than 255 and the game itself might possibly crash.

Re: Could someone explain:
 

God I hate the limitations of some programing language. This I would hope would be one thing that Aaron would improve upon when he gets time. I love to explore, and exploring is one of the things that this game offers that greatly appeals to me. But with 8+ races and their AI on max, they explore far to quickly, and leave me hi and dry. Any other info on the 255 glass system ceiling would be appreciated. Thanks.

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"We've made too many compromises already, too many retreats! They invade our space and we fall back -- they assimilate entire worlds and we fall back! Not again! The line must be drawn here -- this far, no further! And I will make them pay for what they've done!" -- Patrick Stewart as Captain Picard
UCP/TCO Ship Yards

Re: Could someone explain:
 

Well depending on pervasive the use of this variable is, if it is the limiting cause... it might be as simple as a global search and replace or more likely it is something much more complex. No way to tell without knowing the source code better.

Now I assuming my guess is actually on the mark about the 8 bit variable, I wonder why he didn't use at least a 16 bit short or just a regular int. Then again I'm not familiar with what language he used and there could be plenty of other considerations that affected his decision to do it this way. That said I'm not sure you could physically fit 65335 star systems onto the current strategic map. I guess he could have used some intermediary number but I can't remember any simple/primitive variable types on most Languages that are between 8 and 16 bits off the top of my head right now.

Actually I guess that makes sense, I'm guessing that he probably didn't think any of us would want over 65k systems. I like playing on a big map too, but I have trouble remembering where stuff is as it is set up now sometimes. 65k star systems.... sheesh I'd be really lost<G> So maybe it was some sort of compromise. Imagine how slow the game would get and how much memory and disk space it would take to play and save it if the galaxy were that big. It'd be interesting but geeze I barely finish games on a large map now <G>

[This message has been edited by jc173 (edited 08 May 2001).]

Re: Could someone explain:
 

I would also like to have a much bigger game. The number of systems, mapsize and races a SE4 game offers should depend on your PC-system.

Or how about a concept of "galactic sectors". Every sector has the size of a normal huge SE4 game map. But the maps are connected. This means you can jump from one map to the another if you have the appropriate interstellar drive. Each time you jump the game loads the map you choose. (with all its races, wonders, systems etc.)
This means that at the same time is only one galactic sector is active, untill you choose to activate another. (of course you have to have some assets there to do the activation)

Of course this kind of game is not good for a quick MP game over the internet. But it should be good for each long solo game or for a hosted PBEM game too.

The tech cost should be multiplied if such a monster game is played to avoid "running out" of techs in the middle of the game.

Lets see what the map editor and the future in general adds to this topic.

klaus

Re: Could someone explain:
 

i think it's about mem usage

let's do a little math http://www.shrapnelgames.com/ubb/images/icons/icon7.gif :

suppose you have 255 systems

each system can have a name, i don't know the max. characters for a name, but i haven't seen them larger than 32, that is 32 bytes for the name

on average a system has about 10 planets, some have no planets, and some have as much as 15

a planet has three resource values, mineral, organics and radioactives, i haven't seen those above 255%, so one byte per resource would be enough, that is 3 bytes.

a planet also has a atmosphere and type, there are three type, Gas, Rock and Ice
and 5 (?) atmospheres, Oxygen, Hydrogen, Methane, Carbon Dioxide and None. thos could be fitted in 1 byte

then there is the population 4 bytes (common int)

population growth 1 byte

the buildings build on a planet, they could be references to an array in which all the buildings are stored, if so, there is a maximum of 25 (?) buildings on a huge world, that would mean 25 indices, or 25 integers, that is 100 bytes,
a sphereworld can hold 200 buildings, but that is an exception

then there are the ships and units and such but i don't have time include them right now

so for just a galaxy with 255 systems with on average 10 planets per system, you would use

287232 bytes = 280 kb

that ain't much, but suppose you use a 16 bit number for the systems instead of an 8 bit number, then it would be

73531392 bytes = about 70 mb

maybe i'll include ships and units later, or someone else could do it..



[This message has been edited by LemmyM (edited 08 May 2001).]

Re: Could someone explain:
 

I understand that but I don't see how that applies to the argument. Your saying 255 systems takes up X amount of space if you use 8 bit numbers, then you say 16 bit numbers takes up much more than 2X the space.

Your argument hold true if your talking about the number of POSSIBLE combinations, not what the actual memory requirement is. The memory requirement is linear with byte size if you keep the same number of variables for the system, the possible combinations is exponential with byte size since you have twice the number of bits, you have as you said, a lot more combinations.

But we're not talking about combinations, we're talking about straight storage, right? Or did I miss the point entirely? http://www.shrapnelgames.com/ubb/ima...ons/icon12.gif

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by LemmyM:

if you have 8 bits then you have 2 to the 8th possible numbers, that is 256
if you have 16 bits, you have 2 to the 16th possible numbers, that is 65535

so it's not just twice as much, the difference in bits is 16 - 8 = 8, so it is 2 to the 8th times as much

and 70 mb is of course the maximum, if you actually have 65536 systems in a map

[This message has been edited by LemmyM (edited 08 May 2001).]<HR></BLOCKQUOTE>

Re: Could someone explain:
 

Don't forget the storms and other features, as well. There are 169 sectors per system, so that's a lot of room for people to create stuff.

I'd be surprised if he used fixed-length records that recorded everything in an entire system. Variable-length using lists would seem more efficient; for instance, each system could have linked lists of planets, storms, et al.

Pathing could be a concern. If every warp point is a vertex, and edges represent both intra-system travel and inter-system travel, and there are up to 10 warp points per system, 655,360 vertices (65k systems) might be a bit much. That's especially true if there are any O(|V|^{2}) or O(|V|^{3}) algorithms in use.


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-- The thing that goes bump in the night

Re: Could someone explain:
 

Kilo-Ohm:

You're correct. If Aaron were to use 16-bit numbers, he could arbitrarily set a limit of, say, 512 systems, or in fact whatever number he chooses between 0 and 65,535 inclusive. Of course, if he uses any quadratic-order storage (such as an adjacency matrix, but I don't see why he would when the connectivity is limited to 10 per), doubling the system limit still means multipling storage by four. *shrug*

I'd hate to go through the colonies of 100+ captured systems looking for facilities to convert to monoliths, or to add computers, or so forth. Aigh. Please, not without adding text input/output so I can write scripts to input commands. ;-)

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-- The thing that goes bump in the night

Re: Could someone explain:
 

Kilo,

If we assume that Lenny's first number (280Kb)is correct then the second number (70Mb) is also correct.

I'll admit it blew me away at first, but think of it like this. If 280Kb is correct for a galaxy with 255 systems, then simple division gives us a little more than 1Kb per system on average. If we then go to an 18-bit number that allows 65,000 systems http://www.shrapnelgames.com/ubb/images/icons/shock.gif then simple multiplication of a 1Kb per system times 65k systems gives us 65Mb of memory.

What I would like to know is, in my ignorance of computer programming, are if an 8-bit number is too small, is 16-bit our next option? Is not there some number in between we could use? If not I am sure he could use a 16-bit number, and then hard code some logical limit to the number of systems, say 1000 or somethhing like that that would keep the mem usage to a reasonable level.

Geo

Re: Could someone explain:
 

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by KiloOhm:

But we're not talking about combinations, we're talking about straight storage, right? Or did I miss the point entirely? http://www.shrapnelgames.com/ubb/ima...ons/icon12.gif
<HR></BLOCKQUOTE>

in that i case i did mean combinations..
ok, i was a little vague when i posted this

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>
...but suppose you use a 16 bit number for the systems instead of an 8 bit number...
<HR></BLOCKQUOTE>

what i meant was :
suppose you use a 16 bit number to define the number of systems instead of an 8 bit number...
you would then get 65536 systems max.


/ offtopic
<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR> Posted by geoschmo:
If we assume that Lenny's first number
<HR></BLOCKQUOTE>

Lenny ??

[This message has been edited by LemmyM (edited 08 May 2001).]

[This message has been edited by LemmyM (edited 08 May 2001).]

Re: Could someone explain:
 

*zen reels from mathematical gymnastics*

I, um, like klausD's quadrant-jumping idea. http://www.shrapnelgames.com/ubb/images/icons/icon7.gif

I wonder how hard it would be to code something like that?

zen

Re: Could someone explain:
 

Sorry Lemmy. Too many hours stuck in front of the screen playing Space Empires.

They say the eyes are the second thing to go, but I can't remember what the first was...

Re: Could someone explain:
 

Oh, I think it just clicked, you guys were talking about 16bits worth of systems (i.e. 8 bit = 256 systems and 16 bits = 65,000 systems which then makes sense to me on the exponential growth. http://www.shrapnelgames.com/ubb/images/icons/icon7.gif

Thanks, I guess I just needed to read what you guys were saying but put in a differen't way. http://www.shrapnelgames.com/ubb/images/icons/icon7.gif

I thought you meant keeping 256 systems constant, double the data word lengths used to keep track of all the variables in the system, which would only double the storage needed. Now I get it http://www.shrapnelgames.com/ubb/images/icons/icon7.gif


<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by geoschmo:
Kilo,

If we assume that Lenny's first number (280Kb)is correct then the second number (70Mb) is also correct.

I'll admit it blew me away at first, but think of it like this. If 280Kb is correct for a galaxy with 255 systems, then simple division gives us a little more than 1Kb per system on average. If we then go to an 18-bit number that allows 65,000 systems http://www.shrapnelgames.com/ubb/images/icons/shock.gif then simple multiplication of a 1Kb per system times 65k systems gives us 65Mb of memory.

What I would like to know is, in my ignorance of computer programming, are if an 8-bit number is too small, is 16-bit our next option? Is not there some number in between we could use? If not I am sure he could use a 16-bit number, and then hard code some logical limit to the number of systems, say 1000 or somethhing like that that would keep the mem usage to a reasonable level.

Geo<HR></BLOCKQUOTE>

Re: Could someone explain:
 

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>What I would like to know is, in my ignorance of computer programming, are if an 8-bit number is too small, is 16-bit our next option? Is not there some number in between we could use? If not I am sure he could use a 16-bit number, and then hard code some logical limit to the number of systems, say 1000 or somethhing like that that would keep the mem usage to a reasonable level.<HR></BLOCKQUOTE>Since computers "think" in binary arithmetic, at the bit level everything is done in powers of 2. That's why a "kilobyte" is 1024 bytes rather than 1000, and a "megabyte" is 1048576 bytes (1024^2) rather than 1000000. I suppose in theory you could design hardware that used some intermediate value, but I don't know of any real-world examples where it's been done.

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Cap'n Q

Re: Could someone explain:
 

The reason we're stuck with either 8-bit or 16-bit numbers is that computers typically use either 1 byte or 2 byte registers to store numbers. 1 byte=8 bits, so 2 bytes=16 bits.

And, of course, those registers are independent of the actual programming language, since the higher-level programming language instructions are compiled into a set of machine instructions, which are based on the registers (and a few other things, but that's a different topic entirely).

As for why 1 byte = 8 bits, that's a matter for history buffs (hey, I'm only 31 years old, how should I remember the glory days of computing http://www.shrapnelgames.com/ubb/ima...ons/icon12.gif ).

Re: Could someone explain:
 

Zenbudo:
thanks for your kind words.
I cannot answer if it is very complicated to program multiple sector game areas. But I assume such a system is simpler and more flexible than a "monster" universe with thousands of systems located in one gigantic sector.

Especially because the entire data of the different sectors have not to be in RAM the whole time, (because only one sector is active in RAM at the same time) it could be a resource saving method. On the other hand the universe could be nearly infinite. (depending rather on HD-space than RAM)

bye
Klaus

Re: Could someone explain:
 

Another reason for octets --

Load/store instructions are often constrained to 1) operate only on data words or double words, and 2) operate only at *word boundaries* -- e.g. for 32-bit words, only at addresses divisible by 4 (bytes). I'm not familiar with x86 machine language, so I can't be sure.

Ditto for arithmetic. ALUs are designed for a given number of bits in their input -- e.g. handling 32-bit numbers, and outputting 32 bits plus various flags that can be set.

So while one *could* use, say, 14-bit foo, there'll need to be instructions converting back and forth between 14-bit and, say, 32-bit, if you want to do arithmetic. Those 14 bits may need to be shifted and zero-padded to fit into a 32-bit word for arithmetic, memory usage... and depending on language support, the programmer may need to explicitly specify the shifts and other bit operations. It's much more convenient normally to rely on "standard" data types.

(Standard in quotes. C, for instance, specifies only minimum ranges and the ordering -- shorts must be at least 16 bits, and no longer than ints, but other than that could pretty be whatever. Endianness is also not specified. Java is more standardized IIRC -- fixed bit lengths, and network-byte order.)

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-- The thing that goes bump in the night

Re: Could someone explain:
 

Q: If eight bits are a byte, what do you call four bits?

A: A nibble

Re: Could someone explain:
 

What is this???? Greek 101?

http://www.shrapnelgames.com/ubb/images/icons/icon7.gif

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mottlee@gte.net
"Kill em all let God sort em out"

Re: Could someone explain:
 

No, its CS 251 http://www.shrapnelgames.com/ubb/images/icons/icon7.gif

Re: Could someone explain:
 

I don't get your math, your saying for 8 bit numbers, it's 280KB but for 16bit numbers it's 70MB? Your only doubling the # of bits required so You should be 560KB not 70MB...right?

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by LemmyM:
i think it's about mem usage

let's do a little math http://www.shrapnelgames.com/ubb/images/icons/icon7.gif :

suppose you have 255 systems

each system can have a name, i don't know the max. characters for a name, but i haven't seen them larger than 32, that is 32 bytes for the name

on average a system has about 10 planets, some have no planets, and some have as much as 15

a planet has three resource values, mineral, organics and radioactives, i haven't seen those above 255%, so one byte per resource would be enough, that is 3 bytes.

a planet also has a atmosphere and type, there are three type, Gas, Rock and Ice
and 5 (?) atmospheres, Oxygen, Hydrogen, Methane, Carbon Dioxide and None. thos could be fitted in 1 byte

then there is the population 4 bytes (common int)

population growth 1 byte

the buildings build on a planet, they could be references to an array in which all the buildings are stored, if so, there is a maximum of 25 (?) buildings on a huge world, that would mean 25 indices, or 25 integers, that is 100 bytes,
a sphereworld can hold 200 buildings, but that is an exception

then there are the ships and units and such but i don't have time include them right now

so for just a galaxy with 255 systems with on average 10 planets per system, you would use

287232 bytes = 280 kb

that ain't much, but suppose you use a 16 bit number for the systems instead of an 8 bit number, then it would be

73531392 bytes = about 70 mb

maybe i'll include ships and units later, or someone else could do it..

[This message has been edited by LemmyM (edited 08 May 2001).]<HR></BLOCKQUOTE>



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Regards,
KiloOhm

Re: Could someone explain:
 

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by KiloOhm:
I don't get your math, your saying for 8 bit numbers, it's 280KB but for 16bit numbers it's 70MB? Your only doubling the # of bits required so You should be 560KB not 70MB...right?
<HR></BLOCKQUOTE>


if you have 8 bits then you have 2 to the 8th possible numbers, that is 256
if you have 16 bits, you have 2 to the 16th possible numbers, that is 65535

so it's not just twice as much, the difference in bits is 16 - 8 = 8, so it is 2 to the 8th times as much

and 70 mb is of course the maximum, if you actually have 65536 systems in a map

[This message has been edited by LemmyM (edited 08 May 2001).]

Re: Could someone explain:
 

Each entry has a size of one system (planets, populations, values etc.)
so the size of a 16 bit system list would be a lot bigger than twice. It's 2 to the power of 8 times larger (in fact 256 squared).

It would be possible to scale up by factors of 2 but this would require a fair bit of coding just to check how big the system list is every time it parses it.

Bearing in mind I get a noticable pause when looking at my shiplist when there's more that 150 or so entries, a larger galaxy could bring the program to a grinding halt.

And yet again while i'm typing, someone else has already answered.

[This message has been edited by jimbob55 (edited 08 May 2001).]

Re: Could someone explain:
 

Thank god, I thought it was Basic Cobolt 101 with a bit of C, not C++. I was getting confused. Often happens after:

10 cls
20 print "WTF"
30 input = x
40 print "enter your name"
50 print x
60 Print "you just froze up my pc."

Re: Could someone explain:
 

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by klausD:
Especially because the entire data of the different sectors have not to be in RAM the whole time, (because only one sector is active in RAM at the same time) it could be a resource saving method. On the other hand the universe could be nearly infinite. (depending rather on HD-space than RAM)<HR></BLOCKQUOTE>

but then how do you calculate what the AI is doing in the different sectors, if the sector is stored on hd, then after each turn one sector should be saved, another one loaded, let the AI take their turn, and load the next sector

or am i missing something



[This message has been edited by LemmyM (edited 09 May 2001).]

Re: Could someone explain:
 

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? "

Re: Could someone explain:
 

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.

------------------
"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? "

Re: Could someone explain:
 

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>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.<HR></BLOCKQUOTE>
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.

Re: Could someone explain:
 

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. http://www.shrapnelgames.com/ubb/ima...ons/icon12.gif

Either way, thinking about it, I have enough problems securing 250 systems as is. http://www.shrapnelgames.com/ubb/images/icons/icon7.gif Try conquering without glassing worlds...it rilly drags it out and forces you to keep supply lines!

zen

Re: Could someone explain:
 

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

Re: Could someone explain:
 

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by zenbudo:
Either way, thinking about it, I have enough problems securing 250 systems as is. http://www.shrapnelgames.com/ubb/images/icons/icon7.gif Try conquering without glassing worlds...it rilly drags it out and forces you to keep supply lines!

zen<HR></BLOCKQUOTE>

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...

Re: Could someone explain:
 

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>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.

<HR></BLOCKQUOTE>

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.

Re: Could someone explain:
 

Even if all the galaxy data is stored in a database, isn't it still going to be slow? The game engine will have to load up relevant data from disk\database to main memory for the AI's so they can run whatever their various strategy algorithms are.

Re: Could someone explain:
 

The database will only speed up searching for data and retrieving it.

If your AI is scanning through the list of known planets, deciding where to attack, you still have to look at every one.
That's what is gonna take a long time. When the AI gets star maps from an ancient race, trouble brews.

Re: Could someone explain:
 

It wouldn't necessarily take a full sequential scan for determining attack locations, since the plausible attack range is usually small.

Supplies are a concern, at least until solar collectors or the QR. A fleet *could* be launched beyond resupply range, but it would need to either rendezvous with a supply source along the way (which might be beyond the AI); bring a colonizer to create a resupply colony (which would be a nifty tactic to see it use -- but it would have to defend it well, or risk stranding the fleet); or capture a resupply colony (which takes intel, to figure out where one is, *plus* the WPs and so forth may be a problem).

So if it's limited to resupply range, that's basically a series of range Queries, which won't need to touch many disk pages that only deal with far-away systems -- at least with a decent spatial indexing method.

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-- The thing that goes bump in the night

Re: Could someone explain:
 

Wouldn't you have to create a new set of indices or pointers for each race with that method? Unless I'm misunderstanding what you mean by spatial index