Tween Machine's EaseInOut isn't working as expected

[cocefi]

Describe the bug
When tweening position using the EaseInOut method, the frames in the easing out part aren't spaced similarly as the easing in part. The easing out frames stops rather abruptly instead of slowing down. The same issue seems to be present in rotation tweens as well.

To Reproduce
Steps to reproduce the behavior:
Basically following the same steps as your moving mine cart example on YouTube, except with EaseInOut instead of Linear tweening.

Expected behavior
The frame spacing for the easing "out" part of the EaseInOut tween should be similar to the easing "in" part.

Screenshots
In this screenshot you can see that it's easing in nicely, but it's not easing out properly near the end.

System Information (please complete the following information):

• Operating System: Windows 10
• Aseprite Version: v1.3.9.2-x64
• Tool + Tool Version: The Tween Machine v1.3.0
• Size of Canvas (Width x Height): 128x128

[CarbsCode]

Thank you for this bug report @cocefi I do remember struggling with the easeinout and it not being perfect. I'll have to look in to this again to see if I can solve! I believe it was some issue with the rounding that was messing with it but I'll take another look.

[CarbsCode]

Working on this, currently adding a new function called EaseInOutPB which is based on a Parametric Blend function. This should hopefully create a smoother ease in and out transition and more so get the end of the animation easing out a bit nicer. If it ends up working better I will replace the EaseInOut with this new method.

I will need to test this of course to make sure its not running in to any rounding issues but I will add this to The Tween Machine v1.4.0

[cocefi]

Awesome, thanks for the update!