Counting in-game money

pHghost

I have coins in my scene, which the player needs to pick up in order to buy in-game items. I have come across a really strange bug. Right now I only have one cent (0.01) coins, so the amount rises 0.01, 0.02, ..., 0.56, ..., 3.85 etc.

Once the player collects enough coins, the count suddenly goes from 4.41 to 4.4299999999999, then continues 4.4399999999999 and so on.

Any idea why this is happening? Is there any way to "floor" numbers not to integers, but to real numbers with just two decimals?

This is the function for adding a coin:

when 'coin' overlaps with 'player':

destroy actor
change attribute: 'game.coinCount' to: 'game.coinCount'+0.01

The coin display is:

Display text: "money:$"..game.coinCount

UPDATE: I let the game run and the numbers snap back to 'normal' somewhere round 11 dollars.

CodeMonster

why change 'game.coinCount' to game.countcount +0,01?? why not change it to just +1 thats what i always do, if you do this your problem should be fine. so eg:
if coin collide with actor
change attribute game.coincount to game.coincount+1
destroy coin

tatiang

The only thing I can imagine is that you're getting a glitch because you're trying to change an attribute AFTER destroying the actor. Move the destroy actor below and see if that fixes it. I've certainly seen this issue with interpolate but not with change attribute.

You can use prec(game.coinCount,2) to round to two decimals.

If you want to try @CodeMonster's suggestion, just divide game.coinCount by 100 when displaying it.

pHghost

Thanks for the suggestions, I'll try it out and see what it does.

@CodeMonster
The reason I am adding 0.01 is because it is the equivalent of one cent, but the main currency is dollars.

UPDATE: Still happening when attribute is changed before destroy.

tatiang

@pHghost Can you send me a link to download your file? I'd like to take a look since I can't seem to recreate the issue.

pHghost

change attribute: 'game.coinCount' to: prec(game.coinCount, 2)+0.01

That solved the issue. Perfect. Here is a link to the file though, you migh find something lurking under the surface that needs attention:

https://dl.dropboxusercontent.com/u/715828/Testing it.zip

tatiang

Thanks for the file. I see what you mean. I think you should submit it to GameSalad as a bug since your rules look exactly right and there's no good reason for that glitch to happen.

I simplified the file and added more and faster spawners so that you only have to wait a few seconds for the coinCount attribute to reach 4.4299999999999.

pHghost

How do I submit to GameSalad? I'll probably do that.

Thanks.

UPDATE: 'Feedback' button in Creator, got it.

pHghost

In case someone runs into a similar problem, this is a reply from the customer support team -- the issue seems to be related to calculations with 0.1 increments, as I understand it:

The issue you are reporting is one that our Development team is aware of. Unfortunately, this is a demonstration of a limitation on how the engine (and display text) stores floating point calculations. The workaround you suggested: prec(game.coinCount, 2)+0.01 is definitely a valid way to keep your calculations limited to two decimal points.

Apologies for any inconvenience caused.