Issue with While Loops causing the game to crash

[Mayron]

Hi, I'm still learning and this is my first attempt at a while loop so I'm guessing I'm doing something wrong because when I press a button to execute the code, the game crashes.

Before using a while loop I was using an OnUpdate script and basically I want to create a button and when pressed it would execute a block of code every 0.5 seconds (may change depending on if its fast enough). I was using an OnUpdate script but this depended upon the FPS of the game which didn't work for the project I'm working on.

Anyway I want the while loop (or any alternative) to execute a block of code ever 0.5 seconds and not sure how to go about it. This is what I have so far, hopefully this will make more sense than my explanation:

local startMoving, newTopValue = false, 40
local initiate = true
local function MUI_timer(retractEnabled)
        while startMoving do
            initiate = true
            local currentTime = GetTime() 
            local amount = currentTime + 0.5
            while currentTime <= amount do
                if initiate then
                    if retractEnabled then
                        if newTopValue > 40 then
                            newTopValue = newTopValue - 1
                            -- do stuff
                        else
                            retractEnabled = false
                            startMoving = false
                        end
                    elseif newTopValue < 76 then
                        newTopValue = newTopValue + 1
                        -- do stuff
                    else
                        startMoving = false
                    end
                initiate = false
                else
                currentTime = GetTime()
                end
            end
        end
    end
    
    local function Expand_Retract()
        if newTopValue == 40 then -- Expand
            startMoving = true
            MUI_timer(false)
        elseif newTopValue == 76 then -- Retract
            startMoving = true
            MUI_timer(true)
        end
    end

Could anyone guide me on how to fix the crashing issue? Been stuck on this for a long time now.
Thank you for reading!

[Resike]

OnUpdate script doesn't effect on the speed of the code, only how frequently the updating happens.

[Malsomnus]

Long story short, what you're describing cannot be done that way. You can either use OnUpdate and check that 0.5s have passed since the last call, or repeatedly use a 0.5s animation.

[Mayron]

Originally Posted by Resike OnUpdate script doesn't effect on the speed of the code, only how frequently the updating happens.

Yes I know sorry I didn't word that well, basically the code is used to create an animated effect of moving UI elements but if you have bad FPS then the OnUpdate script causes the animation effect to run too slowly. I decided to use a loop with the GetTime() function instead to make it run at a set speed rather than depending on your FPS.

Originally Posted by Malsomnus or repeatedly use a 0.5s animation.

Ok thank you, I only thought you could create an animation for precise things such as an Alpha change. I did not know you could create an animation to do anything you wanted over a set time

[Resike]

Originally Posted by Mayron Yes I know sorry I didn't word that well, basically the code is used to create an animated effect of moving UI elements but if you have bad FPS then the OnUpdate script causes the animation effect to run too slowly. I decided to use a loop with the GetTime() function instead to make it run at a set speed rather than depending on your FPS.

I see you can dinamically slow down the update times on higher fps with "GetFramerate()".

[Malsomnus]

If you want to move UI elements, I strongly suggest you use animations. That is why they exist
You can start here: http://wowprogramming.com/docs/widgets/Animation

[Resike]

Originally Posted by Malsomnus If you want to move UI elements, I strongly suggest you use animations. That is why they exist You can start here: http://wowprogramming.com/docs/widgets/Animation

I'm pretty sure it's using the same OnUpdate functions.

[Mayron]

My "animation" is not one that I thought an animation method could help me with as I wanted to run a function every set seconds until a condition is met. I thought these animations only let you do simpler things like alpha changes, rotations and others.

[Malsomnus]

Originally Posted by Mayron My "animation" is not one that I thought an animation method could help me with as I wanted to run a function every set seconds until a condition is met. I thought these animations only let you do simpler things like alpha changes, rotations and others.

Well that's legit, but they can still be used as a timer (and seem to be popular as such).
To use OnUpdate properly, you need to do something along the lines of:

f.elapsed = 0
f:SetScript ("OnUpdate", function (self, elapsed,...)
    f.elapsed = f.elapsed + elapsed
    if f.elapsed > 0.5 then
        ...
        f.elapsed = 0
    end
end

(Off the top of my head, please don't murder me if I missed something)

Point is, the code you used was simply blocking the game 100% of the time. Being stuck in a while loop means nothing on the screen can update, so the game basically freezes.

[Resike]

Originally Posted by Resike I see you can dinamically slow down the update times on higher fps with "GetFramerate()".

Lets say your update interval value use this: "1 / math.sqrt(GetFrameRate())" then your onupdate code runs ~0.2sec on 30fps and ~0.5sec on 100fps. On 30fps the OnUpdate script runs every 0.03sec, 0.2 * 0.03 = 0.006 and on 100fps on every 0.01sec, 0.5 * 0.01 = 0.005, almost the same values.

Means your animations speed wont change (that much) on different fps values.

[zork]

I have a script that extracts the displayInfo model db from WoW (60k models). I use the animation loop with a 0.001 timer for that purpose. I have a function that will try to extract data but only will be called if a global boolean is set to the true. As long as the extract function runs that boolean is set to false.

local index = 0
local maxIndex = 60000
local canExtract = true
 
local model = CreateFrame("PlayerModel")
local modelData = {}
local tinsert = tinsert
 
local function ExtractModelData()
  index = index + 1
  model:ClearModel()
  model:SetDisplayInfo(index)
  tinsert(modelData, model:GetModel())
  canExtract = true
end
 
local loop = CreateFrame("Frame")
loop.ag = loop:CreateAnimationGroup()
loop.ag.anim = loop.ag:CreateAnimation()
loop.ag.anim:SetDuration(0.001)
loop.ag:SetLooping("REPEAT")
loop.ag:SetScript("OnLoop", function(self)
  if index > maxIndex then self:Stop() end
  if canExtract then
    canExtract = false
    ExtractModelData()
  end
end)
 
loop:SetScript("OnEvent", function(self)
  self.ag:Play()
end)
loop:RegisterEvent("PLAYER_LOGIN")

[Mayron]

Thank you very much for that Zork! Looks interesting and might be what I'm looking for, I know Malsomnus mentioned animations but I was confused at the time since I didn't know animations could work like this. Will experiment with it tonight

[AnrDaemon]

I can put your issue in this way:
OnUpdate runs every frame. That is, every time a game render new frame, it run your OnUpdate handler.
You can do something at that time, or not, matters not. Unless the flame is hidden when interpreter leaves your handler, it will be displayed.
Now, if you are satisfied with ~10 FPS update to whatever you want to do with your frame, OnUpdate will give you enough control over process. There's a very, very little chance that FPS will be lower than that, as it's quickly nearing unplayable status at this point.
The one way to control OnUpdate was given above. Slightly more precise variant is to not reset f.elapsed to zero, but set it to subtraction (f.elapsed - 0.05). Now, if you are running into 0.04 -> 0.06 gap, the next animation step will happen a bit sooner, evening out the curve.

[Resike]

Originally Posted by zork I have a script that extracts the displayInfo model db from WoW (60k models). I use the animation loop with a 0.001 timer for that purpose. I have a function that will try to extract data but only will be called if a global boolean is set to the true. As long as the extract function runs that boolean is set to false. local index = 0 local maxIndex = 60000 local canExtract = true   local model = CreateFrame("PlayerModel") local modelData = {} local tinsert = tinsert   local function ExtractModelData()   index = index + 1   model:ClearModel()   model:SetDisplayInfo(index)   tinsert(modelData, model:GetModel())   canExtract = true end   local loop = CreateFrame("Frame") loop.ag = loop:CreateAnimationGroup() loop.ag.anim = loop.ag:CreateAnimation() loop.ag.anim:SetDuration(0.001) loop.ag:SetLooping("REPEAT") loop.ag:SetScript("OnLoop", function(self)   if index > maxIndex then self:Stop() end   if canExtract then     canExtract = false     ExtractModelData()   end end)   loop:SetScript("OnEvent", function(self)   self.ag:Play() end) loop:RegisterEvent("PLAYER_LOGIN")

Why do you need thoose vaules? Also i think there is much more models in the game then 60k, and a lot of them have the same displayInfo.

[Billtopia]

all you need to know for an OnUpdate animation is a few things

how far does the item have to move?
how long is it supposed to take?
how long has it been?

so say you have to move something 100 pixels over 4 seconds
every second is 25 pixels...
onupdate tells you how long it has been since the last frame redraw

subtract the elapsed from the lifespan of the item and remove the item if it is lifespan < 0 and exit the loop

move your sprite (elapsed * pixelsPerSecond)


exit the loop

[Phanx]

I think you may have posted in the wrong thread, but there's no reason to use an OnUpdate script for animations anymore. Blizzard added a dedicated animation system specifically to replace the use of OnUpdate scripts for animation. If you want to move/rescale/rotate/fade/whatever something, use animations, not OnUpdate scripts. Even if what you want to do isn't an actual animation (eg. "run this function 10 times per second") it's still easier now to use an "animation" than an OnUpdate script, because you don't need to keep track of intervals, implement throttling, etc. yourself.