Added outputs for road curve length, and grade percentage

[RosaryMala]

This still needs some refining in terms of output, but it's working well enough as-is.

So far this changes adds two things to the tool:

The first is it estimates the arc length of a segment being built. I tested that it's accurate for quadrants of a circle, at least, but barring finding out what's the formula for how Skylines decides the road bezier tangents, it works well enough.

The second thing, which depends on the first, is displaying the road grade, as a percentage. Currently it does it on every length measurement, which looks messy, so I might change it so it only shows up on the measurements for the road length, and not for the guidelines.

One more thing that I'd like to do is also show the radius of curvature at each end of the segment.

These additions assist in building networks that follow real-world limits to slope and curve radius.

[RosaryMala]

Here's a preview of how it looks.

[Simie]

Very nice - will look into merging this and updating the mod on the workshop when I get back from holiday.

[RosaryMala]

On trying to use it, the guideline angle is covering up the middle of the road label. Any way of preventing this?

[Simie]

Nice one, I left some comments with one change and then I can merge.

[Simie]

On trying to use it, the guideline angle is covering up the middle of the road label. Any way of preventing this?

Sorry, I'm not sure what you mean by this.

[RosaryMala]

On trying to use it, the guideline angle is covering up the middle of the road label. Any way of preventing this?

Sorry, I'm not sure what you mean by this.

When there's multiple labels being shown (Such as one for the curve radius, and one for the angle) they can overlap.