[core] Coordinate wrapping fixes

- Make returning LatLngs unwrapped by default.
- PointAnnotation and ShapeAnnotation are always wrapped so they can be
  selected via intersection from the visible tile boundaries.
- Fixes LatLng::wrap() calculation.
- Fixes LatLng::unwrapForShortestPath() calculation.

The new unwrapForShortestPath algorithm unwraps the start coordinate
either forwards or backwards depending on the end coordinate value, so
we can always cross the antimeridian when needed and still obtain a
wrapped end coordinate in the end.

Fixes #4214.

2 files changed, 38 insertions, 6 deletions

diff --git a/test/map/transform.cpp b/test/map/transform.cpp
index 98fc1223e5..4412b78b04 100644
--- a/test/map/transform.cpp
+++ b/test/map/transform.cpp
@@ -158,13 +158,17 @@ TEST(Transform, UnwrappedLatLng) {
     ASSERT_NEAR(fromScreenCoordinate.latitude,   37.999999999999829, 0.0001); // 1.71E-13
     ASSERT_NEAR(fromScreenCoordinate.longitude, -76.999999999999773, 0.0001); // 2.27E-13
 
-    LatLng wrappedForwards = state.screenCoordinateToLatLng(state.latLngToScreenCoordinate({ 38, 283, LatLng::Wrapped }));
+    LatLng wrappedForwards = state.screenCoordinateToLatLng(state.latLngToScreenCoordinate({ 38, 283 }));
     ASSERT_NEAR(wrappedForwards.latitude, 37.999999999999716, 0.0001); // 2.84E-13
-    ASSERT_DOUBLE_EQ(wrappedForwards.longitude, fromScreenCoordinate.longitude);
-
-    LatLng wrappedBackwards = state.screenCoordinateToLatLng(state.latLngToScreenCoordinate({ 38, -437, LatLng::Wrapped }));
-    ASSERT_DOUBLE_EQ(wrappedBackwards.latitude, wrappedForwards.latitude);
-    ASSERT_DOUBLE_EQ(wrappedBackwards.longitude, fromScreenCoordinate.longitude);
+    ASSERT_NEAR(wrappedForwards.longitude, 282.99999999988751, 0.0001); // 1.1249E-11
+    wrappedForwards.wrap();
+    ASSERT_NEAR(wrappedForwards.longitude, -77.000000000112493, 0.001); // 1.1249E-11
+
+    LatLng wrappedBackwards = state.screenCoordinateToLatLng(state.latLngToScreenCoordinate({ 38, -437 }));
+    ASSERT_NEAR(wrappedBackwards.latitude, wrappedForwards.latitude, 0.001);
+    ASSERT_NEAR(wrappedBackwards.longitude, -436.99999999988728, 0.001); // 1.1272E-11
+    wrappedBackwards.wrap();
+    ASSERT_NEAR(wrappedBackwards.longitude, -76.99999999988728, 0.001); // 1.1272E-11
 }
 
 TEST(Transform, ConstrainHeightOnly) {
diff --git a/test/util/geo.cpp b/test/util/geo.cpp
index 86f448ebbc..bdf335dc47 100644
--- a/test/util/geo.cpp
+++ b/test/util/geo.cpp
@@ -105,6 +105,34 @@ TEST(LatLng, FromTileID) {
     }
 }
 
+TEST(LatLng, Boundaries) {
+    LatLng coordinate;
+    ASSERT_DOUBLE_EQ(0, coordinate.latitude);
+    ASSERT_DOUBLE_EQ(0, coordinate.longitude);
+
+    coordinate.longitude = -180.1;
+    ASSERT_DOUBLE_EQ(-180.1, coordinate.longitude);
+
+    coordinate.wrap();
+    ASSERT_DOUBLE_EQ(179.90000000000001, coordinate.longitude); // 1E-14
+
+    coordinate.longitude = 180.9;
+    coordinate.wrap();
+    ASSERT_DOUBLE_EQ(-179.09999999999999, coordinate.longitude);
+
+    coordinate.longitude = -360.5;
+    coordinate.wrap();
+    ASSERT_DOUBLE_EQ(-0.5, coordinate.longitude);
+
+    coordinate.longitude = 360.5;
+    coordinate.wrap();
+    ASSERT_DOUBLE_EQ(0.5, coordinate.longitude);
+
+    coordinate.longitude = 360000.5;
+    coordinate.wrap();
+    ASSERT_DOUBLE_EQ(0.5, coordinate.longitude);
+}
+
 TEST(LatLngBounds, FromTileID) {
     {
         const LatLngBounds bounds{ TileID(0, 0, 0, 0) };