Damage effect show problem!

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tetsuken
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Damage effect show problem!

Post by tetsuken » Sat Aug 08, 2015 7:07 am

hello guys, i have a problem and i hope you can help me with it.

I made a function to show damage above the enemies but its not working properly.

here is the code with problem:

Code: Select all

function EffectUpdate(t)
  
  if effectlist ~= nil then
    for i=1,#effectlist do
      
      effectlist[i].time = effectlist[i].time + t*400 -- problem is showing on this line
      effectlist[i].y = effectlist[i].y - 1
      
      if effectlist[i].time > effectlist[i].duration then
        table.remove(effectlist, i)
      end
      
    end
  end
end
description of the problem is this: if i attack the enemy fast the second or third damage gives a index nil problem.
I have no clue where to start solve this if someone can help i will appreciate.

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s-ol
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Re: Damage effect show problem!

Post by s-ol » Sat Aug 08, 2015 10:48 am

You need to iterate the table backwards, when you table.remove the first effect but there were two effects then the second one gets moved to the first slot but you still enter the loop again with i=2.

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print( type(love) )
if false then
  baby:hurt(me)
end

tetsuken
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Joined: Sat May 25, 2013 10:42 pm

Re: Damage effect show problem!

Post by tetsuken » Sat Aug 08, 2015 7:29 pm

I'm not to good on programming could give me an example? how to iterate backward?

i try like this :

Code: Select all

function EffectUpdate(t)
  
  if effectlist ~= nil then

      for i = #effectlist, 1, -1 do 
        if effectlist[i].time > effectlist[i].duration then -- problem here index nil continues
          table.remove(effectlist, i)
        else
          effectlist[i].time = effectlist[i].time + t*400 
          effectlist[i].y = effectlist[i].y - 1
        end
      end
      
  end
end
but the problem persists in te same line
Last edited by tetsuken on Sat Aug 08, 2015 8:25 pm, edited 1 time in total.

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arampl
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Re: Damage effect show problem!

Post by arampl » Sat Aug 08, 2015 8:05 pm

Maybe not use table.remove but effectlist = nil & pairs/ipairs loop?

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TurtleP
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Re: Damage effect show problem!

Post by TurtleP » Sat Aug 08, 2015 8:06 pm

Tetsuken, try the following:

Code: Select all

function EffectUpdate(t)
  
  if effectlist ~= nil then

      for i = #effectlist, 1, -1 do
        if effectlist[i] then 
           if effectlist[i].time > effectlist[i].duration then -- problem here index nil continues
              table.remove(effectlist, i)
           else
              effectlist[i].time = effectlist[i].time + t*400 
              effectlist[i].y = effectlist[i].y - 1
           end
       end
      end
      
  end
end
You should be iterating backwards through the effectlist table since that's what you want to remove. Secondly, it's going to crash if it's trying to index a value which doesn't exist, hence why I suggest putting "if effectlist then".

Hope this helps!

tetsuken
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Posts: 13
Joined: Sat May 25, 2013 10:42 pm

Re: Damage effect show problem!

Post by tetsuken » Sat Aug 08, 2015 8:30 pm

ty that same works perfectly :D i had found the mistake on the first attempt of inverse table remove, but your sample also work fine.

:D actually i think is better then mine

Code: Select all

if effectlist ~= nil then

      for i = #effectlist, 1, -1 do  -- i was make worng here using entitylist instead effectlist
        if effectlist[i].time > effectlist[i].duration then
          table.remove(effectlist, i)
        else
          effectlist[i].time = effectlist[i].time + t*400
          effectlist[i].y = effectlist[i].y - 1
        end
      end
      
  end
ty very much

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