[core] Fix screen coordinates when crossing the antimeridian

If the center and point coordinates are not in the same side of the
antimeridian, we need to unwrap the point longitude to make sure
it can still be seen from the visible side of the antimeridian that is
opposite to the center side.

Fixes #4155.

1 files changed, 22 insertions, 0 deletions

diff --git a/test/map/transform.cpp b/test/map/transform.cpp
index ada20c5872..6b9e960fe6 100644
--- a/test/map/transform.cpp
+++ b/test/map/transform.cpp
@@ -297,3 +297,25 @@ TEST(Transform, MoveBy) {
     ASSERT_NEAR(0, trueCenter.latitude, 1.1);
     ASSERT_NEAR(0, trueCenter.longitude, 1.1);
 }
+
+TEST(Transform, Antimeridian) {
+    MockView view;
+    Transform transform(view, ConstrainMode::HeightOnly);
+    transform.resize({{ 1000, 1000 }});
+    transform.setLatLngZoom({ 0, 0 }, 1);
+
+    const LatLng coordinateSanFrancisco { 37.7833, -122.4167 };
+    ScreenCoordinate pixelSF = transform.latLngToScreenCoordinate(coordinateSanFrancisco);
+    ASSERT_DOUBLE_EQ(151.79409149185352, pixelSF.x);
+    ASSERT_DOUBLE_EQ(383.76774094913071, pixelSF.y);
+
+    transform.setLatLng({ 0, -181 });
+    ScreenCoordinate pixelSFBackwards = transform.latLngToScreenCoordinate(coordinateSanFrancisco);
+    ASSERT_DOUBLE_EQ(666.63617954008976, pixelSFBackwards.x);
+    ASSERT_DOUBLE_EQ(pixelSF.y, pixelSFBackwards.y);
+
+    transform.setLatLng({ 0, 179 });
+    ScreenCoordinate pixelSFForwards = transform.latLngToScreenCoordinate(coordinateSanFrancisco);
+    ASSERT_DOUBLE_EQ(pixelSFBackwards.x, pixelSFForwards.x);
+    ASSERT_DOUBLE_EQ(pixelSFBackwards.y, pixelSFForwards.y);
+}