[core] Add lineMetrics to GeoJSONOptions

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

5 files changed, 17 insertions, 2 deletions

diff --git a/cmake/mason-dependencies.cmake b/cmake/mason-dependencies.cmake
index d4e0378804..cffce0a440 100644
--- a/cmake/mason-dependencies.cmake
+++ b/cmake/mason-dependencies.cmake
@@ -5,7 +5,7 @@ mason_use(variant VERSION 1.1.4 HEADER_ONLY)
 mason_use(unique_resource VERSION cba309e HEADER_ONLY)
 mason_use(rapidjson VERSION 1.1.0 HEADER_ONLY)
 mason_use(boost VERSION 1.65.1 HEADER_ONLY)
-mason_use(geojsonvt VERSION 6.5.1 HEADER_ONLY)
+mason_use(geojsonvt VERSION 6.6.0 HEADER_ONLY)
 mason_use(supercluster VERSION 0.2.2 HEADER_ONLY)
 mason_use(kdbush VERSION 0.1.1-1 HEADER_ONLY)
 mason_use(earcut VERSION 0.12.4 HEADER_ONLY)
diff --git a/include/mbgl/style/sources/geojson_source.hpp b/include/mbgl/style/sources/geojson_source.hpp
index 372e7c7a78..a03b910279 100644
--- a/include/mbgl/style/sources/geojson_source.hpp
+++ b/include/mbgl/style/sources/geojson_source.hpp
@@ -18,6 +18,7 @@ struct GeoJSONOptions {
     uint16_t tileSize = util::tileSize;
     uint16_t buffer = 128;
     double tolerance = 0.375;
+    bool lineMetrics = false;
 
     // Supercluster options
     bool cluster = false;
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);
     }
 }
diff --git a/test/style/conversion/geojson_options.test.cpp b/test/style/conversion/geojson_options.test.cpp
index 4c5a0c9aa4..181189775b 100644
--- a/test/style/conversion/geojson_options.test.cpp
+++ b/test/style/conversion/geojson_options.test.cpp
@@ -32,6 +32,7 @@ TEST(GeoJSONOptions, RetainsDefaults) {
     ASSERT_EQ(converted.maxzoom, defaults.maxzoom);
     ASSERT_EQ(converted.buffer, defaults.buffer);
     ASSERT_EQ(converted.tolerance, defaults.tolerance);
+    ASSERT_EQ(converted.lineMetrics, defaults.lineMetrics);
 
     // Supercluster
     ASSERT_EQ(converted.cluster, defaults.cluster);
@@ -47,7 +48,8 @@ TEST(GeoJSONOptions, FullConversion) {
         "tolerance": 3,
         "cluster": true,
         "clusterRadius": 4,
-        "clusterMaxZoom": 5
+        "clusterMaxZoom": 5,
+        "lineMetrics": true
     })JSON", error);
 
     // GeoJSON-VT
@@ -55,6 +57,7 @@ TEST(GeoJSONOptions, FullConversion) {
     ASSERT_EQ(converted.maxzoom, 1);
     ASSERT_EQ(converted.buffer, 2);
     ASSERT_EQ(converted.tolerance, 3);
+    ASSERT_TRUE(converted.lineMetrics);
 
     // Supercluster
     ASSERT_EQ(converted.cluster, true);