"Pulsating" effect...what's the proper method?

I have frame "frame". I want it to fade from alpha "1" to alpha "0", then back to alpha "1" and repeat until I say otherwise to make a "pulsing" effect.

I tried doing this in a manner like so, and...well...yeah, infinite loops are bad.

while myvariable = 1 do
    alpha = frame:GetAlpha()
    if alpha = 1 then
        UIFrameFadeOut(frame, 1, 1, 0)
    elseif alpha = 0 then
        UIFrameFadeIn(frame, 1, 0, 1)

Hello, Mr. Client Crash.

[d87]

local SHINE_FADE_IN = 0.15;
local SHINE_FADE_OUT = 0.15;
local TICK_PERIOD = 0.35;

local ShineFadeOut = function(frame)
    local fadeInfo = {};
        fadeInfo.mode = "OUT";
        fadeInfo.timeToFade = SHINE_FADE_OUT;
        fadeInfo.finishedFunc = function(self) self.animating = false end;
        fadeInfo.finishedArg1 = frame;
    UIFrameFade(frame, fadeInfo);
end
local ShineFadeIn = function(frame)
    if not frame.animating then
        local fadeInfo = {};
        fadeInfo.mode = "IN";
        fadeInfo.timeToFade = SHINE_FADE_IN;
        fadeInfo.finishedFunc = function(arg1) ShineFadeOut(arg1); end;
        fadeInfo.finishedArg1 = frame;
        frame.animating = true
        UIFrameFade(frame, fadeInfo);
    end
end

f.Shine = function(self)
        ShineFadeIn(self.shinetex)
    end

f.OnUpdate = function (self, time)
        self.OnUpdateCounter = (self.OnUpdateCounter or 0) + time
        if self.OnUpdateCounter < TICK_PERIOD then return end
        self.OnUpdateCounter = 0
        
        self:Shine()
    end

[Xrystal]

Well did a quick search and there isn't much around on that subject so perhaps they hit a wall.

So far all I have seen is people utilising it on Enter and Leave scripts to do the different Fading functions. So how about this.

If you have an Update function that you call every so often perhaps you can put it in there to fadein if it has faded out or to fade out if it has faded in. Then keep a variable to store the last value updated. It's not perfect but might be the only way you can deal with it and even throwing the cycle in every event you watch may be a good idea too. The combination of the two functions may be enough to make it look passable at least.


Edit: Or what d87 said

[nightcracker]

Pretty elegant IMO:

frame.mult = 1
frame.alpha = 1
frame:SetScript("OnUpdate", function(self, elapsed)
    self:SetAlpha(self.alpha)
    self.alpha = self.alpha - elapsed*self.mult
    if self.alpha < 0 and self.mult > 0 then
        self.mult = self.mult*-1
        self.alpha = 0
    elseif self.alpha > 1 and frame.mult < 1 then
        self.mult = self.mult*-1
    end
end)

[Xrystal]

*book marks post so I can come back and ste... erm I mean utilise the code*

Originally Posted by nightcracker Pretty elegant IMO: frame.mult = 1 frame.alpha = 1 frame:SetScript("OnUpdate", function(self, elapsed)     self:SetAlpha(self.alpha)     self.alpha = self.alpha - elapsed*self.mult     if self.alpha < 0 and self.mult > 0 then         self.mult = self.mult*-1         self.alpha = 0     elseif self.alpha > 1 and frame.mult < 1 then         self.mult = self.mult*-1     end end)

[Torhal]

You'll want to hide the frame doing the OnUpdate when it's done, else you'll be needlessly using CPU.

[nightcracker]

Originally Posted by Xrystal *book marks post so I can come back and ste... erm I mean utilise the code*

Feel free to use it(I'm pretty amazed I came up with the mult*-1 trick lol).

Originally Posted by nightcracker Feel free to use it(I'm pretty amazed I came up with the mult*-1 trick lol).

Wow guys...thank you for the quick responses! Working perfectly now.

(Also bookmarking as a reference page)

[nightcracker]

Originally Posted by Amenity Wow guys...thank you for the quick responses! Working perfectly now. (Also bookmarking as a reference page)

If this is going to be a reference, then I'll add something new, a variable to determine speed of the pulse in seconds(don't set it to 0, dividing by 0 FTW):

local speed = 1
frame.mult = 1
frame.alpha = 1
frame:SetScript("OnUpdate", function(self, elapsed)
    elapsed = elapsed*(1/speed)
    self:SetAlpha(self.alpha)
    self.alpha = self.alpha - elapsed*self.mult
    if self.alpha < 0 and self.mult > 0 then
        self.mult = self.mult*-1
        self.alpha = 0
    elseif self.alpha > 1 and frame.mult < 1 then
        self.mult = self.mult*-1
    end
end)

[Nemnacill]

I'm not sure about how it would work in lua, but any pulsating effect can be achieved with a simple sinus function.

pseudo code:
var sequence = 0;
sequence ++;
AlphaProperty = sin(sequence);

this would result in the AlphaProperty going from 0 to 1, then from 1 to 0 and so on. google 'math sin lua' for more info

Good luck

[Hati-EK]

http://www.wowwiki.com/API_UIFrameFlash

UIFrameFlash(frame, fadeInTime, fadeOutTime, flashDuration, showWhenDone, flashInHoldTime, flashOutHoldTime)

if you call it more than once(while it's active) - you'll need something that blocks this calls: (atleast for UIFrameFadeIn it makes it nearly go to infinite time - if called unnecessary times (even if you use :GetAlpha()) - you would need something like spareTime=totaltime-(GetAlpha()/totaltime))

(Note this is for UIFrameFadeIn, and not UIFrameFlash)

local fade_in = {}
local fade_out= {}

--improved UIFrameFadeIn(frame,time,startAlpha,endAlpha,~type)
function lib:UIFrameFadeIn(frame,t,startAlpha,endAlpha,typ)
	local now=GetTime()
	local fname = frame:GetName()
	if typ=='in' then
		local IsInTable,num = self:inTable(fname,fade_in)
		if not IsInTable then
			UIFrameFadeIn(frame,t,startAlpha,endAlpha)
			--tinsert(frame,{icon_name,endTime})
			tinsert(fade_in,{fname,GetTime()+t})
		else
			if now>fade_in[num][2] then
				tremove(fade_in,num)
			end
		end
	elseif typ=='out' then
		local IsInTable,num = self:inTable(fname,fade_out)
		if not IsInTable then
			UIFrameFadeIn(frame,t,startAlpha,endAlpha)
			tinsert(fade_out,{fname,GetTime()+t})
		else
			if now>fade_in[num][2] then
				tremove(fade_out,num)
			end
		end
	end
end

source: LibCooldownIcons-1.0
(Note inTable returns boolean,index of value in table(numeric))

dunno if you can 'calculate' the Pulse-time or want to fix it to some number

[nightcracker]

Originally Posted by Nemnacill I'm not sure about how it would work in lua, but any pulsating effect can be achieved with a simple sinus function. pseudo code: var sequence = 0; sequence ++; AlphaProperty = sin(sequence); this would result in the AlphaProperty going from 0 to 1, then from 1 to 0 and so on. google 'math sin lua' for more info Good luck

True, but that would require an onupdate function. And an onupdate function gets called at every frame. So if you run at 120 FPS your calling a sin function 120 times per second. Not that efficient as running my way(look above).

[Torhal]

Originally Posted by nightcracker <snip>So if you run at 120 FPS your calling a sin function 120 times per second.<snip>

Not true.

do
	local last_update = 0
	local updater = CreateFrame("Frame", nil, UIParent)

	updater:Hide()
	updater:SetScript("OnUpdate",
			  function(self, elapsed)
				  last_update = last_update + elapsed

				  if last_update >= 0.25 then
					  RunSinFunction()
					  last_update = 0
				  end
			  end)
end

That executes the sin function every quarter of a second.

[Hati-EK]

Originally Posted by Torhal Not true. do local last_update = 0 local updater = CreateFrame("Frame", nil, UIParent) updater:Hide() updater:SetScript("OnUpdate", function(self, elapsed) last_update = last_update + elapsed if last_update >= 0.25 then RunSinFunction() last_update = 0 end end) end That executes the sin function every quarter of a second.

last_update = last_update -0.25

is more precise and does not skip seconds (even if this would just be some miliseconds) than reseting the whole value to 0 - (ie last_update could be 0.25182965 - so you would missing 0.00182965 - if you have this ~1000 times there's something missing

[nightcracker]

Originally Posted by Hati-EK last_update = last_update -0.25 is more precise and does not skip seconds (even if this would just be some miliseconds) than reseting the whole value to 0 - (ie last_update could be 0.25182965 - so you would missing 0.00182965 - if you have this ~1000 times there's something missing

Nope, because THIS time if you run at 120 fps then the function would run a lot more then when at 10 fps.

[Torhal]

Originally Posted by Hati-EK last_update = last_update -0.25 is more precise and does not skip seconds (even if this would just be some miliseconds) than reseting the whole value to 0 - (ie last_update could be 0.25182965 - so you would missing 0.00182965 - if you have this ~1000 times there's something missing

This is true, if you're looking to be precise.

[Haleth]

Sorry for thread hijack, but how can this code be applied to a single animation instead of a looping 'pulse'? I'm trying to add opening/closing animations to some addon frames, for example in the following code:

local function Stuffing_Open()
	Stuffing.frame:Show()
end


local function Stuffing_Close()
	Stuffing.frame:Hide()
end

I've tried a couple of things, but no luck.

[Hati-EK]

Originally Posted by Haleth Sorry for thread hijack, but how can this code be applied to a single animation instead of a looping 'pulse'? I'm trying to add opening/closing animations to some addon frames, for example in the following code: local function Stuffing_Open() Stuffing.frame:Show() end local function Stuffing_Close() Stuffing.frame:Hide() end I've tried a couple of things, but no luck.

maybe you are looking for

frame:SetScript('OnShow', doSomethingOnShow)

or frame:SetScript('OnHide', doSomethingOnHide)

?

[Smacker]

Use the built-in animation code:

	local alpha = animationGroup:CreateAnimation("Alpha");
	alpha:SetOrder(order);
	alpha:SetDuration(duration);
	alpha:SetMaxFramerate(fps);
	alpha:SetChange(alphaTo);

[Dawn]

Arrrr, sometimes thread necrotism is good stuff, indeed. I somehow missed this one. *bookmarks thread*