setting progress to a negative makes the timeline go to the end

[d4rklit3]

I am getting this issue where if the progress() gets set to something below 0 it goes to the end of the timeline. Is this supposed to happen?

[GreenSock]

Yes indeed - that's intentional. It's meant to be a convenience, kinda like String.substr() where if the first parameter is negative, it measures from the END of the string. Likewise, if you've got a 10-second tween and you do this:

 

tween.progress(-0.25);

t'd go 25% back from the end, meaning 7.5 seconds into the animation in this case. 

 

And if you do -0.0001, it'll be almost at the very end. 

 

The same applies for regular time-based methods like time(), totalTime(), and seek(). 

 

Make sense now?

 

If you don't want that behavior, I'd recommend just adding a small piece of conditional logic before your progress() call (or in it) that ensures the value is 0 or positive. 

 

tween.progress( (yourValue < 0) ? 0 : yourValue );