Bearing - convert to Double (in degrees)

[mtpdog]

I am trying to switch to SpatialK from another Turf lib.
A stupid question - is there a way to convert Bearing to a simple Double representing bearing in degrees from North? It seems that Rotation could be converted to Double, but there seems to be no simple way to convert Bearing to Rotation and then to Double (without some additional calculations).

[mtpdog]

Is it

North.smallestRotationTo(bearing).inDegrees

?

Update: It works. I would suggest to add Bearing.toDouble() and / or Bearing.inDegrees which is North.smallestRotationTo(bearing).inDegrees

[sargunv]

A Bearing is agnostic to whether you represent bearing relative to North, or to East, and to whether you represent it in the range -180 to 180, or 0 to 360.

If we had Bearing.inDegrees it would be unclear to the reader what the resulting value is relative to and what range it's in.

If you want:

• degrees 0-360 from North: North.clockwiseRotationTo(bearing).inDegrees
  • shorthand: (bearing - North).inDegrees
• degrees -180 to 180 from North: North.smallestRotationTo(bearing).inDegrees
• radians -180 to 180 from East: East.smallestRotationTo(bearing).inRadians

But this example should def be added to the docs

[mtpdog]

Thank you for the examples. This makes sense.

Another option: most other Turf libraries allow bearing to be directly converted to Double meaning North.clockwiseRotationTo(bearing).inDegrees. For such transitions from other libs it is probably worth adding bearing.toDouble as a deprecated function with detailed documentation provided by you.

[jgillich]

We already have the rotationFromNorth property, could we not make that public? It would be a convenient shorthand and also save a tiny bit of processing

[sargunv]

Regular Turf.js and other ports typically don't have a Bearing type at all; they just represent bearing in degrees, but in some places as 0-360 and other places as -180-180. I was hoping to avoid that ambiguity.

The private bearing.rotationFromNorth is just the same as (bearing - North)

[sargunv]

Generally when designing an interface for a library, I like to optimize for the least ambiguity and greatest clarity for the reader, even if that results in more verbosity for the writer.

If across your application you're always representing bearing as 0-360 degrees from north, you can add that extension getter to your application