How do you divide without decimals?

ID:161468
 
May 3 2008, 6:32 pm
Is there a way to force byond to do integer rounding, so you don't end up with a decimal number after a division? Rounding is kind of expensive.
May 3 2008, 6:53 pm
Use the round() proc. For example:

round(22/7) returns 3.

Here's another example that's more practical:

mob
    var
        attack = 10
        defense = 3
    verb/Attack(mob/M in oview(1))
        var/damage = attack - M.defense //Returns 3.333...
        M.health -= round(damage) //M loses var damage rounded, which equals 3.
May 4 2008, 6:29 am
In response to Darkmag1c1an11
I said rounding was expensive. Meaning I would rather avoid using that for something that has to run very frequently.
May 4 2008, 6:34 am
In response to Obs
Well, depending on what you're dividing by, integer division is possible. For example, if dividing by a power of 2, you can use bit-shifting:
64 >> 1    // 64 / 2
64 >> 2    // 64 / 4
64 >> 3    // 64 / 8
64 >> 4    // 64 / 16
64 >> 5    // 64 / 32
64 >> 6    // 64 / 64

...and so on. Otherwise, round() isn't overly expensive.

Hiead
May 4 2008, 6:55 am
In response to Obs
I don't think rounding is actually as expensive as you think; probably less so than the division itself. If you're running this extremely frequently and dividing by powers of 2, then bit-shifting will definitely help you.

Lummox JR
May 4 2008, 8:33 am
In response to Hiead
ah I should have thought of that.

Good. I will make use of this