Java-Gaming.org Java4K winners: [ by our judges | by the community ]         
Featured games (67)
games approved by the League of Dukes 		Games in Showcase (∞)
games submitted by our members



News: Read the Java Gaming Resources, or peek at the official Java tutorials
 
    Home     Help   Search   Login   Register   
Java-Gaming.org > Games Center > Contests > Finished Contests > 4K Game Competition - 2009 > Help?
Pages: [1]
  Print  
  Help?  (Read 2282 times)
0 Members and 2 Guests are viewing this topic.
Offline EnderGT

Jr. Member
**

Posts: 98
« on: 2008-12-07 22:57:06 »
The posts on 4KJO seem to have disappeared. Can the author please contact me? I'm getting a lot of exceptions that are telling me that the jar file is corrupt... but yet it runs just fine.

Also, I thought I'd followed all the "rules" for making the code as small as possible, and my code isn't really doing THAT much, but I've only just now been able to get it under 7 kb. I'm hoping one of the wizards here can take a look and point out any obvious mistakes I'm making.

I'm trying to make an online poker game (server and client in the same jar). Currently it's Omaha Hi-Lo 8, I will probably change it to Hold 'Em to save a few more bytes.

Thanks in advance.

Edit: No, it doesn't yet work, there's a few bugs I still need to fix. I just thought I'd take a look at how I was doing on size, and realized the crisis.
Offline moogie

JGO Strike Force
***

Posts: 775
Medals: 5


Java games rock!
« Reply #1 on: 2008-12-07 23:46:53 »
refer to the first post of the Links, tips and goodies thread. It has links to the 4KJO tool I created Smiley
Offline moogie

JGO Strike Force
***

Posts: 775
Medals: 5


Java games rock!
« Reply #2 on: 2008-12-08 00:26:56 »
Some suggestions:

I think most of your class size bloat comes from the different API classes you make use of all of which add to the class's symbol table size.

i would suggest try using only one array and use different Index offsets for logically different instead of many different arrays each representing a different logical component.

Try reducing the number of local variables used. If you can, reuse a local variable for different logical purposes.

try using the ? opertor when conditionally assigning values... e.g for

1  
2  
3  
4  
5  
6  
7  
8  
9  
10  
11  
12  
option = FOLD;
              if (active > 1 && raises < 4) {
                if ((bet+raise) < cash[action]) {
                  if (bet == 0) {
                    option |= BET;
                  } else {
                     option |= RAISE;
                  }
                } else {
                  option |= ALLIN;
                }
              }


make it:
1  
2  
3  
4  
5  
6  
7  
8  
9  
10  
option = (active > 1 && raises < 4) ?
  option |= ((bet+raise) < cash[action])?
     (bet == 0) ?
       BET
     :
       RAISE
   :
      ALLIN
: 
   FOLD



replace all division where possible by bitwise operation... i.e.
1  
 /2
  to
1  
 >> 1

 
if possible convert all for loops to loop backward. The comaprision to 0 test will therefore occur often and be more easily compressable.
Games published by our own members! Go get 'em!
Offline Markus_Persson

JGO Kernel
*****

Posts: 2092
Medals: 10


Mojang Specifications
« Reply #3 on: 2008-12-08 03:18:52 »
Quote from: moogie on 2008-12-08 00:26:56
replace all division where possible by bitwise operation... i.e.
1  
 /2
  to
1  
 >> 1

Those two take up exactly the same number of bytes..
Play Minecraft!
Offline moogie

JGO Strike Force
***

Posts: 775
Medals: 5


Java games rock!
« Reply #4 on: 2008-12-08 04:24:31 »
hmm, in my previous entry it gained me a couple of bytes... perhaps the different bytes used to represent >> 1 was more favorable when compressing my JAR entry?
Offline Markus_Persson

JGO Kernel
*****

Posts: 2092
Medals: 10


Mojang Specifications
« Reply #5 on: 2008-12-08 05:11:24 »
I was mostly being a smartass. Wink

/2 and >>1 happen to use the same amount of bytes, and so does /4 and >>2.
But for divisions by 8, 16, and 32, you save one byte by using >> instead.
Divisions by 64 uses the same number of bytes as >> since iconst_N doesn't go higher than 5, and /64 is >>6.
Using right shift instead of divisions by 128 through 16384 saves one byte.
Over 16384, you're using the constant pool, so now you're saving even more by using >>.

So in general, it's (probably) a good idea to use >>, but for the /2 case, any benefit you saw probably just came from compression randomness. =)
Play Minecraft!
Offline Abuse

JGO Kernel
*****

Posts: 1866
Medals: 5


falling into the abyss of reality
« Reply #6 on: 2008-12-08 09:22:24 »
For completeness, it's worth mentioning proguard automatically replaces all multiplication by powers of 2 with the equivalent shift, as it's a safe speed & size optimisation.

It doesn't do the same for division because it's an unsafe optimisation, due to the 2 operations not being entirely equivalent (/2 rounds toward 0, >>1 rounds toward -ive infinity)
So, adding the shifts manually (where safe to do so) may well save you some bytes.
Offline EnderGT

Jr. Member
**

Posts: 98
« Reply #7 on: 2008-12-08 09:47:20 »
Quote from: moogie on 2008-12-07 23:46:53
refer to the first post of the Links, tips and goodies thread. It has links to the 4KJO tool I created Smiley
Funny, I looked right at it at didn't see it. I also searched for "4KJO" and got no results. Odd.

Anyway, is there any chance you could take a look at the exceptions I'm seeing? I'll post the jar file I used if you need.
Offline EnderGT

Jr. Member
**

Posts: 98
« Reply #8 on: 2008-12-08 09:54:37 »
Quote from: moogie on 2008-12-08 00:26:56
I think most of your class size bloat comes from the different API classes you make use of all of which add to the class's symbol table size.
I'll take a look and see if there's any way I can trim this down.

Quote from: moogie on 2008-12-08 00:26:56
i would suggest try using only one array and use different Index offsets for logically different instead of many different arrays each representing a different logical component.
I was going to have a single array with different indices being the different variables I needed (for the singleton variables) but it seemed that that would actually add to the size. There's only a couple of other arrays that I could do this for, but I'll keep this in mind.

Quote from: moogie on 2008-12-08 00:26:56
Try reducing the number of local variables used. If you can, reuse a local variable for different logical purposes.
I've been trying to reuse wherever possible, but I'll look harder for more opportunities.

Quote from: moogie on 2008-12-08 00:26:56
try using the ? opertor when conditionally assigning values...
Is this true? I thought someone, way back when, said that this way actually took more bytes...

Quote from: moogie on 2008-12-08 00:26:56
if possible convert all for loops to loop backward. The comaprision to 0 test will therefore occur often and be more easily compressable.
Will do.

Thanks for taking a look!
Offline moogie

JGO Strike Force
***

Posts: 775
Medals: 5


Java games rock!
« Reply #9 on: 2008-12-08 14:00:42 »
Quote from: EnderGT on 2008-12-08 09:54:37
I'll take a look and see if there's any way I can trim this down.
I was going to have a single array with different indices being the different variables I needed (for the singleton variables) but it seemed that that would actually add to the size. There's only a couple of other arrays that I could do this for, but I'll keep this in mind.
I've been trying to reuse wherever possible, but I'll look harder for more opportunities.
Is this true? I thought someone, way back when, said that this way actually took more bytes...
Will do.

Thanks for taking a look!
[/quote

I had thought the same about using one monolithic array, but it did end up better as it reduced the symbol table and i was able to use/abuse the monolithic array to perform some game logic by carefully ordering the array and thus reducing the number of conditional statements i needed.

I thought about writing a tool that would parse a java/class file and list potential local variables that could be reused at different points in the execution... perhaps i should do this.

it might be the case that the ? operator takes more bytes, however in the example listed above, it also reduce the number of |= operators... so it may give a reduction.

Your game logic seems very complex with many conditions and states... with out simplifying the logic or abusing some behavior of java or math to represent your game logic I do not think you will be able to fit it with in 4k Sad
Games published by our own members! Go get 'em!
Offline EnderGT

Jr. Member
**

Posts: 98
« Reply #10 on: 2008-12-08 14:19:57 »
Quote from: moogie on 2008-12-08 14:00:42
Your game logic seems very complex with many conditions and states... with out simplifying the logic or abusing some behavior of java or math to represent your game logic I do not think you will be able to fit it with in 4k Sad
I'm starting to think the same... I've gotten it down to 6037 bytes by inlining the network code instead of using DataInput/OutputStreams, and by removing a few unnecessary states and combining a few others, but I'm not sure what else I'll be able to remove without making it simply unplayable.

Edit: now 5750 bytes... a few more trouble spots to attack before I switch from Omaha to Hold'Em to save another chunk. I'd rather stay with Omaha if I can - limit hold'em is somewhat boring IMO.
Pages: [1]
  Print  
 
 
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.16 | SMF © 2011, Simple Machines Valid XHTML 1.0! Valid CSS!
Page created in 0.067 seconds with 21 queries.