Mist

ID:263268
 
Aug 16 2006, 5:09 am
Code:
//Mist Proc

        Mist()
            var/area/Outside/O
            if(O.ismist == 0)
                O.ismist = 1
                for(O in oview(src,45))
                    O.icon = 'Spells.dmi'
                    O.icon_state = "mist"
                    sleep(1800)
                    O.ismist = 0
                    O.icon = null
                    O.icon_state = null
                    break
            else
                return

//area
area
    Outside
        var
            ismist = 0
            israin = 0
            issnow = 0

//verb

mob
    verb
        Mister()
            usr.Mist()


Problem description:
Everytime I use the Mister verb, I get this error

runtime error: Cannot read null.ismist
proc name: Mist (/mob/proc/Mist)
usr: Dead_Demon (/mob/Player)
src: Dead_Demon (/mob/Player)
call stack:
Dead_Demon (/mob/Player): Mist()
Dead_Demon (/mob/Player): Mister()
Aug 16 2006, 5:29 am
Your problem lies in your mist proc:
        Mist()
            var/area/Outside/O


You define O, but you don't set it to anything. By default, when you define a variable, it is set to null. That is why you're getting a "null.ismist" error.

To fix this, you have to use locate() to get the actual instance of the /area/Outside object.

However, I also notice that you're trying to make mist in a certain area. /area objects are a special type, and there is only one instance of the object in the world, even if you put them in different z levels. If you're trying to make mist in a certain area, looking at area objects wouldn't be such a good idea. Otherwise, if you want to make it misty everywhere outside, then it will work fine.

Mist()
  var/area/Outside/O = locate() in world // find an instance of the area object in the world
  if(O && !O.ismist) // if one is found, and it isn't already misty
    O.ismist = 1
    O.icon = 'Spells.dmi'
    O.icon_state = "mist"
    spawn(1800)
      O.ismist = 0
      O.icon null
      O.icon_state = null


~~> Unknown Person
Aug 16 2006, 6:58 am
In response to Unknown Person
Thanks! Now I know how to fix the null.whatever runtime error :)
Aug 20 2006, 1:36 pm
In response to Unknown Person
I haven't had time to fix my mist code until today, and I did, and nothing happens. I already checked to make sure I had the icon_state and such right. Am I calling the proc right?

        Mist()
            var/area/Outside/O = locate() in world
            if(O && !O.ismist)
                O.ismist = 1
                O.icon = 'Spells.dmi'
                O.icon_state = "Mist"
                spawn(1800)
                    O.ismist = 0
                    O.icon = null
                    O.icon_state = null
            ..()
mob
    verb
        Mister()
            usr.Mist()
Aug 20 2006, 2:18 pm
In response to Dead_Demon
This works:
mob
    verb
        Mister()
            for(var/area/Outside/O in oview(45))
                Mist(O)
    proc
        Mist(area/Outside/O)
            if(!O.ismist)
                O.ismist = 1
                O.icon = 'Spells.dmi'
                O.icon_state = "mist"
                sleep(1800)
                O.ismist = 0
                O.icon = null
                O.icon_state = null
            else return

But if you can't see it you need to set the areas layer like this:
area
    Outside
        layer=MOB_LAYER+2 //Sets the Outside area's layer 2 above the mob's layer
        var
            ismist = 0
            israin = 0
            issnow = 0
Aug 20 2006, 2:29 pm
In response to Hellsing4
oO Whoops. Thanks
Aug 20 2006, 2:58 pm
In response to Dead_Demon
your welcome