Implemented azimuthToBearing

[basvdijk]

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[basvdijk]

Implemented #2399

[rowanwins]

👍 @basvdijk

[JamesLMilner]

I think we can merge this :)

[rowanwins]

Requires a tidyup of the function so that the tests pass

[rowanwins]

Pretty sure this isn't working as expected @basvdijk now that I've run CI and seen the failing tests.

[stebogit]

this works 😃:

function azimuthToBearing(angle) {
  angle = angle % 360;
  if (angle > 0) return angle > 180 ? angle - 360 : angle;
  return angle < -180 ? angle + 360 : angle;
}

test('azimuthToBearing', t => {
  t.equal(azimuthToBearing(0), 0);
  t.equal(azimuthToBearing(360), 0);
  t.equal(azimuthToBearing(180), 180);

  t.equal(azimuthToBearing(40), 40);
  t.equal(azimuthToBearing(40 + 360), 40);

  t.equal(azimuthToBearing(-35), -35);
  t.equal(azimuthToBearing(-35 - 360), -35);

  t.equal(azimuthToBearing(255), -105);
  t.equal(azimuthToBearing(255 + 360), -105);

  t.equal(azimuthToBearing(-200), 160);
  t.equal(azimuthToBearing(-200 - 360), 160);

  t.end();
});

[stebogit]

I think angle should not be restricted to 0-360, but any number, you can easily normalize it with mod 360

[stebogit]

this works 😃:

function azimuthToBearing(angle) {
  angle = angle % 360;
  if (angle > 0) return angle > 180 ? angle - 360 : angle;
  return angle < -180 ? angle + 360 : angle;
}

test('azimuthToBearing', t => {
  t.equal(azimuthToBearing(0), 0);
  t.equal(azimuthToBearing(360), 0);
  t.equal(azimuthToBearing(180), 180);

  t.equal(azimuthToBearing(40), 40);
  t.equal(azimuthToBearing(40 + 360), 40);

  t.equal(azimuthToBearing(-35), -35);
  t.equal(azimuthToBearing(-35 - 360), -35);

  t.equal(azimuthToBearing(255), -105);
  t.equal(azimuthToBearing(255 + 360), -105);

  t.equal(azimuthToBearing(-200), 160);
  t.equal(azimuthToBearing(-200 - 360), 160);

  t.end();
});