[question] array of booleans or integer?(optimization)

ARES[ro] · **Author**

In my plugin i made my own variable wich stores certain flags:
for example
isAlive (int) and i do bitwise OR shifted bits (id) to set isAlive, id
the compiler gives me a tag mismatch warning every time i use if(!getBit( isAlive, id ))
so my question is shud i use an integer or bool:isAlive[33] to avoid the tag mismatch warnings.
So my question is shud i use an integer or an array of booleans?

**Bugsy** · *Last edited by Bugsy; 10-15-2010 at 19:29.*

Use a single variable and leave it un-tagged. If you need further help post or pm your problem code.

**Bugsy** · 10-15-2010 , 19:34 Re: [question] array of booleans or integer?(optimization)

Here's a organized way of storing flags

You can have up to 32 flags.

PHP Code:


			
enum ( <<=1 )
{
     IsAlive = 1,
     IsAdmin,
     HasGodmode,
     HasSpeed,
}

#define SetFlag(%1,%2)   (g_PlayerFlags[%1] |= %2)
#define RemoveFlag(%1,%2)   (g_PlayerFlags[%1] &= ~(%2))
#define CheckFlag(%1,%2)   (g_PlayerFlags[%1] & %2)

new g_PlayerFlags[ 33 ]; 

SetFlag( id , IsAdmin );

RemoveFlag( id , IsAdmin );

if ( CheckFlag( id , IsAdmin ) )
{
    //Code
}

ARES[ro] · 10-15-2010 , 19:46 Re: [question] array of booleans or integer?(optimization)

Well yeah i have macros too ^^

PHP Code:


			
#define getBit(%1,%2)    (%1 & 1 << (%2 & 31))

and love the way u put it more thanks

fysiks · 10-15-2010 , 19:48 Re: [question] array of booleans or integer?(optimization)

Quote:

Originally Posted by ARES[ro]

Well yeah i have macros too ^^

PHP Code:


			
#define getBit(%1,%2)    (%1 & 1 << (%2 & 31))

and love the way u put it more thanks

I think where yours is wrong is the that it should be "%2 % 31". Bugsy, correct me if I'm wrong.

**Bugsy** · *Last edited by Bugsy; 10-15-2010 at 19:57.*

IMO, it would be easier to manage and code using what I posted above where each player their own bitfield of options versus having a variable of each flag and setting a player id bit to 1/0.

@fysiks, there was a discussion somewhere regarding the speed of id-1, id % 31, and id & 31, id & 31 turned out to be the most efficient.

ARES[ro] · 10-15-2010 , 20:00 Re: [question] array of booleans or integer?(optimization)

So its faster? I only counted out the server itself. Im glad to hear.
Also i do know about assembly code and such i just dont look up each operator im using lol!

**Bugsy** · 10-15-2010 , 20:04 Re: [question] array of booleans or integer?(optimization)

Quote:

Originally Posted by ARES[ro]

So its faster? I only counted out the server itself. Im glad to hear.
Also i do know about assembly code and such i just dont look up each operator im using lol!

Yes, X & 31 is more efficient than X % 31 or X-1. Not that you would notice a difference using either but it's always best to use the most efficient methods.

ARES[ro] · *Last edited by ARES[ro]; 10-15-2010 at 20:24.*

Well youre right in assembly commands it does make a HUGE difference. I did learn in college that % uses a division and some shifts and AND wil save you a lot of cpu with square numbers.