`ServoImpl#getPosition` incorrectly reversing a scaled servo.

[kevinthegreat1]

In ServoImpl#getPosition,reverse is called on the unscaled position in getPosition. While in ServoImpl#setPosition, reverse is called on scaled values. This means Servo#getPosition return incorrect values for reversed scaled servos.

Example

Let's say we have a reversed servo scaled from 0 to 0.5 instead of from 0 to 1:

Setting:

1. setPosition(0.5) -> sets an actual position of 0.25 for the servo.

Getting:

1. ServoController#getServoPosition returns 0.25 (line 178)
2. reverse reverses the value from 0.25 to 0.75 (line 179)
3. Range.scale scales the value from 0.75 to 1.5 (line 180)
4. Range.clip clips the value to 1

Result

We expect to get 0.5, not 1

Code Screenshot

[kevinthegreat1]

I know you guys don't accept prs, but I'd be happy to submit one if needed.

[alan412]

Thank you for this catch. I have put it as an issue on our internal repo. We'll likely fix it for the off-season release.

[alan412]

Also @kevinthegreat1 , all of the detail was very helpful!!

[alan412]

I think the issue is actually in the setting. and it should be like this:

Setting:

setPosition(0.5) -> SHOULD set an actual position of 0.75 for the servo.

Getting:

ServoController#getServoPosition returns 0.75 (line 178)
reverse reverses the value from 0.75 to 0.25 (line 179)
Range.scale scales the value from 0.25 to 0.5 (line 180)
Range.clip does nothing

@kevinthegreat1 - agree?

[kevinthegreat1]

Thanks for the quick response. I believe both approaches will have the same effect, however, changing setPosition would break current servos.

Since right now, setPosition(0.5) sets 0.25, but if it's changed to set 0.75, then it will break more current contraptions and people would have to recalibrate their servos. Changing getPosition will break less stuff, but both approaches will fix the issue.