Merge pull request #255 from Pilot-Marc/route-step-pivot-point

Fix minor error with placement of route steps

Sources/ARKit-CoreLocation/Extensions/CLLocation+Extensions.swift

@@ -91,6 +91,19 @@ public extension CLLocation {
         let x = cos(lat1) * sin(lat2) - sin(lat1) * cos(lat2) * cos(dLon)
         return atan2(y, x).radiansToDegrees
     }
+
+    /// Returns the midpoint between two locations
+    /// Note: Only usable for short distances like MKPolyline segments
+    func approxMidpoint(to: CLLocation) -> CLLocation {
+        return CLLocation(
+            coordinate: CLLocationCoordinate2D(
+                latitude: (coordinate.latitude + to.coordinate.latitude) / 2,
+                longitude: (coordinate.longitude + to.coordinate.longitude) / 2
+            ),
+            altitude: (altitude + to.altitude) / 2
+        )
+    } // approxMidpoint(to:)
+
 }
 
 public extension CLLocation {

Sources/ARKit-CoreLocation/Nodes/LocationNode.swift

@@ -144,6 +144,7 @@ open class LocationNode: SCNNode {
             }
         } else {
             //Calculates distance based on the distance within the scene, as the location isn't yet confirmed
+            //TODO: This yields zero, perhaps we should investigate
             adjustedDistance = Double(position.distance(to: position))
 
             scale = SCNVector3(x: 1, y: 1, z: 1)

Sources/ARKit-CoreLocation/Nodes/PolylineNode.swift

@@ -73,6 +73,7 @@ private extension PolylineNode {
         for i in 0 ..< polyline.pointCount - 1 {
             let currentLocation = CLLocation(coordinate: points[i].coordinate, altitude: altitude)
             let nextLocation = CLLocation(coordinate: points[i + 1].coordinate, altitude: altitude)
+            let midLocation = currentLocation.approxMidpoint(to: nextLocation)
 
             let distance = currentLocation.distance(from: nextLocation)
 
@@ -82,13 +83,10 @@ private extension PolylineNode {
 
             let bearing = -currentLocation.bearing(between: nextLocation)
 
-            // This pivot translation in the +Z direction will cause the box to be
-            // rendered a bit away from its true location. The actual factor should
-            // probably be a parameter or property of some sort.
-            boxNode.pivot = SCNMatrix4MakeTranslation(0, 0, 0.5 * Float(distance))
+            // Orient the line to point from currentLoction to nextLocation
             boxNode.eulerAngles.y = Float(bearing).degreesToRadians
 
-            let locationNode = LocationNode(location: currentLocation, tag: tag)
+            let locationNode = LocationNode(location: midLocation, tag: tag)
             locationNode.addChildNode(boxNode)
 
             locationNodes.append(locationNode)

changelog.md

@@ -1,5 +1,6 @@
 # Changelog
 - 1.2.2
+   - [PR #255 - Fix minor error with placement of route steps](https://github.com/ProjectDent/ARKit-CoreLocation/pull/255)
    - [PR #249 - Fix Memory Leak](https://github.com/ProjectDent/ARKit-CoreLocation/pull/249)
    - [PR #244 - Improve geodesy calculations and test coverage](https://github.com/ProjectDent/ARKit-CoreLocation/pull/244)
    - [PR #240 - Fix build error, update compiler checks](https://github.com/ProjectDent/ARKit-CoreLocation/pull/240)