Rotate map based on heading while walking

[1ec5]

When the user is walking, they can more easily turn around than when driving. It’s more important for the map to indicate the direction the user is facing than the direction they’re walking, in the event that they turn around to orient themselves. Essentially, MGLUserTrackingMode.trackWithHeading is more appropriate than MGLUserTrackingMode.trackWithCourse for the walking use case.

When the current step’s transportType is walking, the camera’s heading should be set to CLHeading.trueHeading, not CLLocation.course:

mapbox-navigation-ios/MapboxNavigation/NavigationMapView.swift

Line 336 in 68745c9

let newCamera = camera ?? MGLMapCamera(lookingAtCenter: location.coordinate, altitude: altitude, pitch: 45, heading: location.course)

/cc @mapbox/navigation-ios @lauri-rustanius

[1ec5]

Note that, due to a map SDK limitation, this fix may cause location tracking to lag: mapbox/mapbox-gl-native#3625 (comment). So we may want to throttle rotation changes to allow the center coordinate to catch up, so to speak.

[1ec5]

When we rely on CLHeading, we need to update CLLocationManager.headingOrientation whenever the device’s orientation changes. Otherwise, the heading could be up to 90° off whenever the user holds the phone in landscape orientation.

https://github.com/mapbox/mapbox-gl-native/blob/f3c3dc49e231208e75db64b53c5e92bb9647a661/platform/ios/src/MGLMapView.mm#L5865-L5905

[1ec5]

#2215 fixes this issue.

Note that, due to a map SDK limitation, this fix may cause location tracking to lag: mapbox/mapbox-gl-native#3625 (comment). So we may want to throttle rotation changes to allow the center coordinate to catch up, so to speak.

I’m inclined to treat this issue as tail work and piggyback on any forthcoming solution for mapbox/mapbox-gl-native#3625. I don’t think it’ll end up being a huge problem in practice, because walking speeds are so low compared to driving speeds.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[stale]

Stale.