GeoJSON point clustering (#5724)

* add supercluster dependency
* prepare GeoJSONTile for Supercluster
* prepare GeoJSONSource for accepting options
* try removing mbgl::GeoJSON
* fix setGeoJSON types
* add GeoJSONSource getURL
* add geojson to include path
* add Supercluster index in GeoJSONSource
* fix GeoJSONSource getZoomRange
* bring back mbgl::GeoJSON header
* fix tidy warnings hopefully
* try test-suite with enabled cluster test
* fix formatting in clustering-related files

3 files changed, 110 insertions, 32 deletions

diff --git a/include/mbgl/style/conversion/source.hpp b/include/mbgl/style/conversion/source.hpp
index 00c6afb9fe..c4b2fe303f 100644
--- a/include/mbgl/style/conversion/source.hpp
+++ b/include/mbgl/style/conversion/source.hpp
@@ -1,12 +1,12 @@
 #pragma once
 
+#include <mbgl/style/conversion.hpp>
+#include <mbgl/style/conversion/geojson.hpp>
+#include <mbgl/style/conversion/tileset.hpp>
 #include <mbgl/style/source.hpp>
 #include <mbgl/style/sources/geojson_source.hpp>
 #include <mbgl/style/sources/raster_source.hpp>
 #include <mbgl/style/sources/vector_source.hpp>
-#include <mbgl/style/conversion.hpp>
-#include <mbgl/style/conversion/tileset.hpp>
-#include <mbgl/style/conversion/geojson.hpp>
 
 namespace mbgl {
 namespace style {
@@ -18,17 +18,17 @@ public:
     template <class V>
     Result<std::unique_ptr<Source>> operator()(const V& value, const std::string& id) const {
         if (!isObject(value)) {
-            return Error { "source must be an object" };
+            return Error{ "source must be an object" };
         }
 
         auto typeValue = objectMember(value, "type");
         if (!typeValue) {
-            return Error { "source must have a type" };
+            return Error{ "source must have a type" };
         }
 
         optional<std::string> type = toString(*typeValue);
         if (!type) {
-            return Error { "source type must be a string" };
+            return Error{ "source type must be a string" };
         }
 
         if (*type == "raster") {
@@ -38,7 +38,7 @@ public:
         } else if (*type == "geojson") {
             return convertGeoJSONSource(id, value);
         } else {
-            return Error { "invalid source type" };
+            return Error{ "invalid source type" };
         }
     }
 
@@ -57,14 +57,15 @@ private:
 
         optional<std::string> url = toString(*urlVal);
         if (!url) {
-            return Error { "source url must be a string" };
+            return Error{ "source url must be a string" };
         }
 
         return *url;
     }
 
     template <class V>
-    Result<std::unique_ptr<Source>> convertRasterSource(const std::string& id, const V& value) const {
+    Result<std::unique_ptr<Source>> convertRasterSource(const std::string& id,
+                                                        const V& value) const {
         Result<variant<std::string, Tileset>> urlOrTileset = convertURLOrTileset(value);
         if (!urlOrTileset) {
             return urlOrTileset.error();
@@ -75,7 +76,7 @@ private:
         if (tileSizeValue) {
             optional<float> size = toNumber(*tileSizeValue);
             if (!size || *size < 0 || *size > std::numeric_limits<uint16_t>::max()) {
-                return Error { "invalid tileSize" };
+                return Error{ "invalid tileSize" };
             }
             tileSize = *size;
         }
@@ -84,7 +85,8 @@ private:
     }
 
     template <class V>
-    Result<std::unique_ptr<Source>> convertVectorSource(const std::string& id, const V& value) const {
+    Result<std::unique_ptr<Source>> convertVectorSource(const std::string& id,
+                                                        const V& value) const {
         Result<variant<std::string, Tileset>> urlOrTileset = convertURLOrTileset(value);
         if (!urlOrTileset) {
             return urlOrTileset.error();
@@ -94,13 +96,70 @@ private:
     }
 
     template <class V>
-    Result<std::unique_ptr<Source>> convertGeoJSONSource(const std::string& id, const V& value) const {
+    Result<std::unique_ptr<Source>> convertGeoJSONSource(const std::string& id,
+                                                         const V& value) const {
         auto dataValue = objectMember(value, "data");
         if (!dataValue) {
-            return Error { "GeoJSON source must have a data value" };
+            return Error{ "GeoJSON source must have a data value" };
+        }
+
+        GeoJSONOptions options;
+
+        const auto maxzoomValue = objectMember(value, "maxzoom");
+        if (maxzoomValue) {
+            if (toNumber(*maxzoomValue)) {
+                options.maxzoom = static_cast<uint8_t>(*toNumber(*maxzoomValue));
+            } else {
+                return Error{ "GeoJSON source maxzoom value must be a number" };
+            }
+        }
+
+        const auto bufferValue = objectMember(value, "buffer");
+        if (bufferValue) {
+            if (toNumber(*bufferValue)) {
+                options.buffer = static_cast<uint16_t>(*toNumber(*bufferValue));
+            } else {
+                return Error{ "GeoJSON source buffer value must be a number" };
+            }
+        }
+
+        const auto toleranceValue = objectMember(value, "tolerance");
+        if (toleranceValue) {
+            if (toNumber(*toleranceValue)) {
+                options.tolerance = static_cast<double>(*toNumber(*toleranceValue));
+            } else {
+                return Error{ "GeoJSON source tolerance value must be a number" };
+            }
+        }
+
+        const auto clusterValue = objectMember(value, "cluster");
+        if (clusterValue) {
+            if (toBool(*clusterValue)) {
+                options.cluster = *toBool(*clusterValue);
+            } else {
+                return Error{ "GeoJSON source cluster value must be a boolean" };
+            }
+        }
+
+        const auto clusterMaxZoomValue = objectMember(value, "clusterMaxZoom");
+        if (clusterMaxZoomValue) {
+            if (toNumber(*clusterMaxZoomValue)) {
+                options.clusterMaxZoom = static_cast<uint8_t>(*toNumber(*clusterMaxZoomValue));
+            } else {
+                return Error{ "GeoJSON source clusterMaxZoom value must be a number" };
+            }
+        }
+
+        const auto clusterRadiusValue = objectMember(value, "clusterRadius");
+        if (clusterRadiusValue) {
+            if (toNumber(*clusterRadiusValue)) {
+                options.clusterRadius = static_cast<double>(*toNumber(*clusterRadiusValue));
+            } else {
+                return Error{ "GeoJSON source clusterRadius value must be a number" };
+            }
         }
 
-        auto result = std::make_unique<GeoJSONSource>(id);
+        auto result = std::make_unique<GeoJSONSource>(id, options);
 
         if (isObject(*dataValue)) {
             Result<GeoJSON> geoJSON = convertGeoJSON(*dataValue);
@@ -111,7 +170,7 @@ private:
         } else if (toString(*dataValue)) {
             result->setURL(*toString(*dataValue));
         } else {
-            return Error { "GeoJSON data must be a URL or an object" };
+            return Error{ "GeoJSON data must be a URL or an object" };
         }
 
         return std::move(result);
diff --git a/include/mbgl/style/sources/geojson_source.hpp b/include/mbgl/style/sources/geojson_source.hpp
index 3736dd44bc..37ddce1bcc 100644
--- a/include/mbgl/style/sources/geojson_source.hpp
+++ b/include/mbgl/style/sources/geojson_source.hpp
@@ -3,15 +3,46 @@
 #include <mbgl/style/source.hpp>
 #include <mbgl/util/geojson.hpp>
 
+#include <mapbox/geojson.hpp>
+
+namespace mapbox {
+
+namespace geojsonvt {
+class GeoJSONVT;
+} // namespace geojsonvt
+
+namespace supercluster {
+class Supercluster;
+} // namespace supercluster
+
+} // namespace mapbox
+
 namespace mbgl {
 namespace style {
 
+using GeoJSONVTPointer = std::unique_ptr<mapbox::geojsonvt::GeoJSONVT>;
+using SuperclusterPointer = std::unique_ptr<mapbox::supercluster::Supercluster>;
+
+struct GeoJSONOptions {
+    // GeoJSON-VT options
+    uint8_t maxzoom = 18;
+    uint16_t buffer = 128;
+    double tolerance = 0.375;
+
+    // Supercluster options
+    bool cluster = false;
+    uint16_t clusterRadius = 50;
+    uint8_t clusterMaxZoom = 17;
+};
+
 class GeoJSONSource : public Source {
 public:
-    GeoJSONSource(const std::string& id);
+    GeoJSONSource(const std::string& id, const GeoJSONOptions options_ = GeoJSONOptions());
 
     void setURL(const std::string& url);
-    void setGeoJSON(GeoJSON&&);
+    void setGeoJSON(const GeoJSON&);
+
+    std::string getURL();
 
     // Private implementation
 
diff --git a/include/mbgl/util/geojson.hpp b/include/mbgl/util/geojson.hpp
index 3fd8c6ac4b..b4e789a3ac 100644
--- a/include/mbgl/util/geojson.hpp
+++ b/include/mbgl/util/geojson.hpp
@@ -1,22 +1,10 @@
 #pragma once
 
-#include <memory>
-
-namespace mapbox {
-namespace geojsonvt {
-class GeoJSONVT;
-} // namespace geojsonvt
-} // namespace mapbox
+#include <mapbox/geojson.hpp>
 
 namespace mbgl {
 
-class GeoJSON {
-public:
-    GeoJSON(std::unique_ptr<mapbox::geojsonvt::GeoJSONVT>);
-    GeoJSON(GeoJSON&&);
-    ~GeoJSON();
-
-    std::unique_ptr<mapbox::geojsonvt::GeoJSONVT> impl;
-};
+using GeoJSON = mapbox::geojson::geojson;
+using FeatureCollection = mapbox::geojson::feature_collection;
 
 } // namespace mbgl