WoWInterface - Division by zero for XP

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- WoD Beta archived threads (https://www.wowinterface.com/forums/forumdisplay.php?f=151)

- - Division by zero for XP (https://www.wowinterface.com/forums/showthread.php?t=49603)

Division by zero for XP

Hi @all

I use for my XP display the following lines:

Lua Code:

local function GetPlayerXP()
    return UnitXP("player"), UnitXPMax("player")
end

and

Lua Code:

local XP, maxXP = GetPlayerXP()
local restXP = GetXPExhaustion()
local percXP = math.floor((XP / maxXP) * 100)

The last line gives rise to the error mentioned in the thread title. The funny thing here is that I use the same script on the live server and it works there. Also on the Beta server, the correct values are calculated and shown what you see on the screenshot below.

The error also occurs only at login and at each subsequent reload it exists not even. My question now is ... Do I have a mistake, I do not see the forest for the trees or Blizzard has an error return values?

Thanks in advance for all input.

greetz
liquid

They've done this for the past few betas - I believe it's so they can optimize the default UI; cut out any instances of division-by-zero that are otherwise handled (likely less efficiently) by the live version's Lua parser. Division by zero is, after all, something most programmers code against, not for.

So then it would simply wait and see what is no satisfactory answer :(

Lua Code:

local percXP = (XP == 0) and 0 or math.floor((XP / maxXP) * 100)

Thanks Torhal to solve the problem with this idea I did not come. I should just take a break :o

Shouldn't that be (maxXP == 0)?

Could be netter. I will test it :)
Thanks for all help!

Quote:

Originally Posted by Torhal (Post 295055)

Lua is one of the few languages that makes use of the full IEEE 754 specification for floating point numbers by allowing the casting of divide-by-zero into signed infinity. Whether this is natively done by the computer's floating point processor or trapped and substituted for by the Lua interpreter, it would be much faster since the execution lies in C code rather than forcing the check through the interpreter itself.

Their decision to force Lua to throw division-by-zero errors was to make it act more like C.

Quote:

Originally Posted by Bashiok

This is an intended change to keep the lua engine in line with changes to our game engine.

I'm curious why you have the extra function and function call and aren't just doing this?

Lua Code:

local XP, maxMP = UnitXP("player"), UnitXPMax("player")

Quote:

Originally Posted by SDPhantom (Post 295060)

Shouldn't that be (maxXP == 0)?

I wouldn't see why - no matter your level, the maximum experience for that level would certainly be above 0. However, at level 1, with no experience gained...

It happened, otherwise the error would've never been thrown. The code as-is can already handle if XP is zero, but not maxXP.

Quote:

Originally Posted by SDPhantom (Post 295081)

It happened, otherwise the error would've never been thrown. The code as-is can already handle if XP is zero, but not maxXP.

Meh. This is what I get for skimming. Whatever - I set him on the right path, at least. I hope. Damn!

@Seerah
You're right. The function is a relict from the old script within the UI I had only copied.

@Torhal
Thanks to you it works fine :)

@SDPhantom
with (maxXP == 0) the script throw a error if I want to display the value in a tooltip because of the nil-value.

Quote:

Originally Posted by liquidbase (Post 295104)

with (maxXP == 0) the script throw a error if I want to display the value in a tooltip because of the nil-value.

So wrap the whole thing in a check to make sure the maxXP isn't zero, and skip doing anything with XP in that case, since there's no valid information to show.

If you need help with specific changes, you'll have to show your code.

Quote:

Originally Posted by liquidbase (Post 295104)

with (maxXP == 0) the script throw a error if I want to display the value in a tooltip because of the nil-value.

If you're combining both mine and Torhal's conditions, there may be unexpected results depending on how you write it. It will need to look like this.

Code:

local percXP = (maxXP == 0) and 0 or math.floor((XP / maxXP) * 100)

Otherwise, I don't see how it's possible that a nil can pass through without throwing another error at this line.

If you post your entire code, we'll be able to help better and may catch problems that you might not see.

Sorry for the late response.
The error occurs on line 89 if the character has no rested experience. Without (maxXP == 0) the script works as should. And the problem is not "nil" (my mistake in the interpretation) but it is a boolean instead of strings returned. With the expression the script throws the following error:

Lua Code:

DuffedUI-8.0015\modules\misc\experience.lua:89: bad argument #4 to "format" (string expected, got boolean)
<in C code>
DuffedUI-8.0015\modules\misc\experience.lua:89: in function <DuffedUI\modules\misc\experience.lua:67>
 
Locals:
XP = 0
maxXP = 0
restXP = nil
percXP = true
(*temporary) = <function> defined =[C]:-1
(*temporary) = mouseFrame_Text {
 0 = <userdata>
}
IsMaxLevel = <function> defined @Interface\AddOns\DuffedUI\modules\misc\experience.lua:20
xpBar = Experience_xpBar {
 0 = <userdata>
 lockShow = 0
}
restedxpBar = Experience_restedxpBar {
 0 = <userdata>
 lockShow = 0
}
repBar = Experience_repBar {
 0 = <userdata>
 lockShow = 0
}
barHeight = 10
backdrop = Experience_Backdrop {
 0 = <userdata>
 backdrop = <unnamed> {
 }
}
Text = mouseFrame_Text {
 0 = <userdata>
}

Thanks for all help, you guys are great :)

Complete Script:

Lua Code:

local D, C, L = unpack(select(2, ...))
 
local barHeight, barWidth = 10, 378
local font, fontsize, flags = C["media"].font, 11, "THINOUTLINE"
local barTex, flatTex = C["media"].normTex
local color = RAID_CLASS_COLORS[D.Class]
local FactionInfo = {
    [1] = {{ 170/255, 70/255,  70/255 }, "Hated", "FFaa4646"},
    [2] = {{ 170/255, 70/255,  70/255 }, "Hostile", "FFaa4646"},
    [3] = {{ 170/255, 70/255,  70/255 }, "Unfriendly", "FFaa4646"},
    [4] = {{ 200/255, 180/255, 100/255 }, "Neutral", "FFc8b464"},
    [5] = {{ 75/255,  175/255, 75/255 }, "Friendly", "FF4baf4b"},
    [6] = {{ 75/255,  175/255, 75/255 }, "Honored", "FF4baf4b"},
    [7] = {{ 75/255,  175/255, 75/255 }, "Revered", "FF4baf4b"},
    [8] = {{ 155/255,  255/255, 155/255 }, "Exalted","FF9bff9b"},
}
 
function colorize(r) return FactionInfo[r][3] end
 
local function IsMaxLevel()
    if UnitLevel("player") == MAX_PLAYER_LEVEL then
        return true
    end
end
 
local backdrop = CreateFrame("Frame", "Experience_Backdrop", UIParent)
backdrop:Size(barWidth, barHeight)
backdrop:SetPoint("BOTTOMLEFT", UIParent, "BOTTOMLEFT", 7, 178)
backdrop:SetBackdropColor(C["general"].backdropcolor)
backdrop:SetBackdropBorderColor(C["general"].backdropcolor)
backdrop:CreateBackdrop()
 
local xpBar = CreateFrame("StatusBar",  "Experience_xpBar", backdrop, "TextStatusBar")
xpBar:SetWidth(barWidth)
xpBar:SetHeight(GetWatchedFactionInfo() and (barHeight) or barHeight)
xpBar:SetPoint("TOP", backdrop,"TOP", 0, 0)
xpBar:SetStatusBarTexture(barTex)
if C["general"].classcolor then xpBar:SetStatusBarColor(color.r, color.g, color.b) else xpBar:SetStatusBarColor(31/255, 41/255, 130/255) end
 
local restedxpBar = CreateFrame("StatusBar", "Experience_restedxpBar", backdrop, "TextStatusBar")
restedxpBar:SetHeight(GetWatchedFactionInfo() and (barHeight) or barHeight)
restedxpBar:SetWidth(barWidth)
restedxpBar:SetPoint("TOP", backdrop, "TOP", 0, 0)
restedxpBar:SetStatusBarTexture(barTex)
restedxpBar:Hide()
 
local repBar = CreateFrame("StatusBar", "Experience_repBar", backdrop, "TextStatusBar")
repBar:SetWidth(barWidth)
repBar:SetHeight(IsMaxLevel() and barHeight - 0 or 0)
repBar:SetPoint("BOTTOM", backdrop, "BOTTOM", 0, 0)
repBar:SetStatusBarTexture(barTex)
 
local mouseFrame = CreateFrame("Frame", "Experience_mouseFrame", backdrop)
mouseFrame:SetAllPoints(backdrop)
mouseFrame:EnableMouse(true)
 
local Text = mouseFrame:CreateFontString("mouseFrame_Text", "OVERLAY")
Text:SetFont(font, fontsize, flags)
Text:SetPoint("CENTER", mouseFrame, "CENTER", 0, 0)
 
backdrop:SetFrameLevel(0)
restedxpBar:SetFrameLevel(1)
repBar:SetFrameLevel(2)
xpBar:SetFrameLevel(2)
mouseFrame:SetFrameLevel(3)
 
local function updateStatus()
    local XP, maxXP, restXP = UnitXP("player"), UnitXPMax("player"), GetXPExhaustion()
    local percXP = ((XP == 0) and (maxXP == 0)) or (math.floor((XP / maxXP) * 100))
 
    if IsMaxLevel() then
        xpBar:Hide()
        restedxpBar:Hide()
        repBar:SetHeight(barHeight)
        if not GetWatchedFactionInfo() then backdrop:Hide() else backdrop:Show() end
    else
        xpBar:SetMinMaxValues(min(0, XP), maxXP)
        xpBar:SetValue(XP)
 
        if restXP then
            Text:SetText(format("%s/%s (%s%%|cffb3e1ff+%d%%|r)", D.ShortValue(XP), D.ShortValue(maxXP), percXP, restXP / maxXP * 100))
            restedxpBar:Show()
            local r, g, b = color.r, color.g, color.b
            restedxpBar:SetStatusBarColor(r, g, b, .40)
            restedxpBar:SetMinMaxValues(min(0, XP), maxXP)
            restedxpBar:SetValue(XP + restXP)
        else
            restedxpBar:Hide()
            Text:SetText(format("%s/%s (%s%%)", D.ShortValue(XP), D.ShortValue(maxXP), percXP))
        end
 
        if GetWatchedFactionInfo() then
            xpBar:SetHeight(barHeight)
            restedxpBar:SetHeight(barHeight)
            repBar:SetHeight(2)
            repBar:Show()
        else
            xpBar:SetHeight(barHeight)
            restedxpBar:SetHeight(barHeight)
            repBar:Hide()
        end
    end
 
    if GetWatchedFactionInfo() then
        local name, rank, minRep, maxRep, value = GetWatchedFactionInfo()
        repBar:SetMinMaxValues(minRep, maxRep)
        repBar:SetValue(value)
        repBar:SetStatusBarColor(unpack(FactionInfo[rank][1]))
        Text:SetText(format("%d / %d (%d%%)", value - minRep, maxRep - minRep, (value - minRep) / (maxRep - minRep) * 100))
    end
 
    mouseFrame:SetScript("OnEnter", function()
        GameTooltip:SetOwner(mouseFrame, "ANCHOR_BOTTOMLEFT", -3, barHeight)
        GameTooltip:ClearLines()
        if not IsMaxLevel() then
            GameTooltip:AddLine("Experience:")
            GameTooltip:AddLine(string.format("XP: %s/%s (%d%%)", D.CommaValue(XP), D.CommaValue(maxXP), (XP / maxXP) * 100))
            GameTooltip:AddLine(string.format("Remaining: %s", D.CommaValue(maxXP - XP)))
            if restXP then GameTooltip:AddLine(string.format("|cffb3e1ffRested: %s (%d%%)", D.CommaValue(restXP), restXP / maxXP * 100)) end
        end
        if GetWatchedFactionInfo() then
            local name, rank, min, max, value = GetWatchedFactionInfo()
            if not IsMaxLevel() then GameTooltip:AddLine(" ") end
            GameTooltip:AddLine(string.format("Reputation: %s", name))
            GameTooltip:AddLine(string.format("Standing: |c"..colorize(rank) .. "%s|r", FactionInfo[rank][2]))
            GameTooltip:AddLine(string.format("Rep: %s/%s (%d%%)", D.CommaValue(value - min), D.CommaValue(max - min), (value - min)/(max - min) * 100))
            GameTooltip:AddLine(string.format("Remaining: %s", D.CommaValue(max - value)))
        end
        GameTooltip:Show()
    end)
    mouseFrame:SetScript("OnLeave", function() GameTooltip:Hide() end)
end
 
local frame = CreateFrame("Frame",nil,UIParent)
frame:RegisterEvent("PLAYER_LEVEL_UP")
frame:RegisterEvent("PLAYER_XP_UPDATE")
frame:RegisterEvent("UPDATE_EXHAUSTION")
frame:RegisterEvent("CHAT_MSG_COMBAT_FACTION_CHANGE")
frame:RegisterEvent("UPDATE_FACTION")
frame:RegisterEvent("PLAYER_ENTERING_WORLD")
frame:SetScript("OnEvent", updateStatus)

Do what SDPhantom says.

Quote:

Originally Posted by liquidbase (Post 295160)

local XP, maxXP, restXP = UnitXP("player"), UnitXPMax("player"), GetXPExhaustion()
local percXP = ((XP == 0) and (maxXP == 0)) or (math.floor((XP / maxXP) * 100))

That second line is the problem; I don't think it's doing what you think it's doing. What you wrote is the equivalent of this:

Code:

if XP == 0 and maxXP == 0 then

    percXP = true

else

    percXP = floor(XP / maxXP * 100)

end

SDPhantom's suggestion will prevent the error from showing up, but I'd suggest doing this instead:

Code:

local XP, maxXP, restXP = UnitXP("player"), UnitXPMax("player"), GetXPExhaustion()

if not maxXP or maxXP == 0 then return end

local percXP = floor(XP / maxXP * 100)

There's no point in going on with the rest of your display logic if you don't have any valid information to display, or you just end up displaying wrong information.

Done it Phanx.
Thanks for all the input :)