[core] Add lineMetrics to GeoJSONOptions

This patch also bumps geojson-vt-cpp version to 6.6.0,
which enables the `lineMetrics` option.

2 files changed, 11 insertions, 0 deletions

diff --git a/src/mbgl/style/conversion/geojson_options.cpp b/src/mbgl/style/conversion/geojson_options.cpp
index 52a5030c34..77340e5f1d 100644
--- a/src/mbgl/style/conversion/geojson_options.cpp
+++ b/src/mbgl/style/conversion/geojson_options.cpp
@@ -77,6 +77,16 @@ optional<GeoJSONOptions> Converter<GeoJSONOptions>::operator()(const Convertible
         }
     }
 
+    const auto lineMetricsValue = objectMember(value, "lineMetrics");
+    if (lineMetricsValue) {
+        if (toBool(*lineMetricsValue)) {
+            options.lineMetrics = *toBool(*lineMetricsValue);
+        } else {
+            error = { "GeoJSON source lineMetrics value must be a boolean" };
+            return nullopt;
+        }
+    }
+
     return { options };
 }
 
diff --git a/src/mbgl/style/sources/geojson_source_impl.cpp b/src/mbgl/style/sources/geojson_source_impl.cpp
index fd6d7d3013..5ec3909d3e 100644
--- a/src/mbgl/style/sources/geojson_source_impl.cpp
+++ b/src/mbgl/style/sources/geojson_source_impl.cpp
@@ -64,6 +64,7 @@ GeoJSONSource::Impl::Impl(const Impl& other, const GeoJSON& geoJSON)
         vtOptions.extent = util::EXTENT;
         vtOptions.buffer = ::round(scale * options.buffer);
         vtOptions.tolerance = scale * options.tolerance;
+        vtOptions.lineMetrics = options.lineMetrics;
         data = std::make_unique<GeoJSONVTData>(geoJSON, vtOptions);
     }
 }