Compass is Moving in Opposite Direction of Phone

[ghost]

https://jira.nyt.net/browse/MO-7115

[cdzombak]

assigning @jaredsinclair as a second reviewer.

[jaredsinclair]

Okay, I've made a few minor modifications. The changes @JulietaFernandez made were spot-on. The changes I made:

1. Change the default reference angle to 0. I didn't realize until now that the compass view transform in NYTVideo was adding M_PI to the received value to compensate for NYT360Video's non-zero reference angle. My change makes the implementation for the host app much simpler. Note: this means NYTVideo will need to be updated after picking up this change.
2. Updated the unit tests to be in reference to one rotation rather than pi which can make reading the tests more difficult. I think it's easier to grasp "one rotation" than "pi" rotations.
3. I added documentation with notes about all this stuff.

[jaredsinclair]

cc @cdzombak

[jaredsinclair]

👍🏻

[cdzombak]

Thank you both, @JulietaFernandez and @jaredsinclair.