tweening delta calculation minor error, what to do?

[Doidel]

Hey Rob and all who want to participate in this discussion

While the delta tweening allows some cool stuff I encountered an issue that puts it a bit in question: Like all coding languages big numbers suffer from imprecision, e.g. leading to the following output on console from the last step of a tween...

old val 0.0029999999999996696
difference -0.0030000000000000027 
new Value -3.3306690738754696e-16

...with the goal of tweening to 0. While such entirely small differences do not matter e.g. with tweening _translate, it definitely does matter with opacity: If opacity == 0 then it's fully transparent BUT if opacity ==-3.3306690738754696e-16 (i.e. almost 0) the engine has no clue what to do with that and the opacity goes to default 1, being fully opaque.

I won't write down the choices how to handle this 'cause they are more or less obvious, but what would you (Rob & guys) choose to do?

(Hint: Math.round() can't be used because it would break the tween combining. You'd like 'round the other tween too' that is running the same time.)

Thanks in advance for some assistance!

[Irrelon]

I suggest something like toFixed(2) rather than rounding? Or maybe not. I don't know.

I guess that an internal value could be kept that if the (time * delta value) is > than the internal value, to round it before applying it to the tween? Or something like that.

[Doidel]

I changed the delta correction at the end of the tween to perform a rounding according to the number of digits. We'll discuss it per Skype. But I guess this version works, it has good performance but will cut the floating point precision to about 15 digits (yet 15 is quite a lot, I guess that will do...) Anyway. Skype.

[Irrelon]

Yay! Ok we can discuss further via Skype :) I am back to work on Monday after a much needed Christmas break, although so much went wrong this holiday it's been pretty stressful.

Someone smashed into my car while it was parked and I was 150 miles from home, damaging the alloy wheel and breaking the rear axel, then drove away without leaving any details. Then I borrowed my parents car to get home, arrived and realised the keys to the house were in my car so had to hire a 24 hr lock smith to get in, then once we were in, realised that the central heating had stopped working because our boiler was broken!

Crazy.

[Doidel]

Oh dear... That's some bad luck x/

Yes sure, Monday will do!

[Irrelon]

For the log, we discussed this via Skype and @Doidel has come up with a solution and pushed the update to the repo.

[Mavor]

cool beans :)