1 files changed, 58 insertions, 2 deletions

diff --git a/platform/darwin/src/MGLFeature.mm b/platform/darwin/src/MGLFeature.mm
index d24c807625..fbf262af29 100644
--- a/platform/darwin/src/MGLFeature.mm
+++ b/platform/darwin/src/MGLFeature.mm
@@ -1,4 +1,6 @@
+#import "MGLFoundation_Private.h"
 #import "MGLFeature_Private.h"
+#import "MGLCluster.h"
 
 #import "MGLPointAnnotation.h"
 #import "MGLPolyline.h"
@@ -19,6 +21,11 @@
 #import <mbgl/style/conversion/geojson.hpp>
 #import <mapbox/feature.hpp>
 
+// Cluster constants
+static NSString * const MGLClusterIdentifierKey = @"cluster_id";
+static NSString * const MGLClusterCountKey = @"point_count";
+const NSUInteger MGLClusterIdentifierInvalid = NSUIntegerMax;
+
 @interface MGLEmptyFeature ()
 @end
 
@@ -92,6 +99,31 @@ MGL_DEFINE_FEATURE_ATTRIBUTES_GETTER();
 
 @end
 
+@implementation MGLPointFeatureCluster
+
+- (NSUInteger)clusterIdentifier {
+    NSNumber *clusterNumber = MGL_OBJC_DYNAMIC_CAST([self attributeForKey:MGLClusterIdentifierKey], NSNumber);
+    MGLAssert(clusterNumber, @"Clusters should have a cluster_id");
+    
+    if (!clusterNumber) {
+        return MGLClusterIdentifierInvalid;
+    }
+    
+    NSUInteger clusterIdentifier = [clusterNumber unsignedIntegerValue];
+    MGLAssert(clusterIdentifier <= UINT32_MAX, @"Cluster identifiers are 32bit");
+    
+    return clusterIdentifier;
+}
+
+- (NSUInteger)clusterPointCount {
+    NSNumber *count = MGL_OBJC_DYNAMIC_CAST([self attributeForKey:MGLClusterCountKey], NSNumber);
+    MGLAssert(count, @"Clusters should have a point_count");
+    
+    return [count unsignedIntegerValue];
+}
+@end
+
+
 @interface MGLPolylineFeature ()
 @end
 
@@ -318,14 +350,38 @@ MGL_DEFINE_FEATURE_ATTRIBUTES_GETTER();
  */
 template <typename T>
 class GeometryEvaluator {
+private:
+    const mbgl::PropertyMap *shared_properties;
+    
 public:
+    GeometryEvaluator(const mbgl::PropertyMap *properties = nullptr):
+        shared_properties(properties)
+    {}
+    
     MGLShape <MGLFeature> * operator()(const mbgl::EmptyGeometry &) const {
         MGLEmptyFeature *feature = [[MGLEmptyFeature alloc] init];
         return feature;
     }
 
     MGLShape <MGLFeature> * operator()(const mbgl::Point<T> &geometry) const {
-        MGLPointFeature *feature = [[MGLPointFeature alloc] init];
+        Class pointFeatureClass = [MGLPointFeature class];
+        
+        // If we're dealing with a cluster, we should change the class type.
+        // This could be generic and build the subclass at runtime if it turns
+        // out we need to support more than point clusters.
+        if (shared_properties) {
+            auto clusterIt = shared_properties->find("cluster");
+            if (clusterIt != shared_properties->end()) {
+                auto clusterValue = clusterIt->second;
+                if (clusterValue.template is<bool>()) {
+                    if (clusterValue.template get<bool>()) {
+                        pointFeatureClass = [MGLPointFeatureCluster class];
+                    }
+                }
+            }
+        }
+        
+        MGLPointFeature *feature = [[pointFeatureClass alloc] init];
         feature.coordinate = toLocationCoordinate2D(geometry);
         return feature;
     }
@@ -443,7 +499,7 @@ id <MGLFeature> MGLFeatureFromMBGLFeature(const mbgl::Feature &feature) {
         ValueEvaluator evaluator;
         attributes[@(pair.first.c_str())] = mbgl::Value::visit(value, evaluator);
     }
-    GeometryEvaluator<double> evaluator;
+    GeometryEvaluator<double> evaluator(&feature.properties);
     MGLShape <MGLFeature> *shape = mapbox::geometry::geometry<double>::visit(feature.geometry, evaluator);
     if (!feature.id.is<mapbox::feature::null_value_t>()) {
         shape.identifier = mbgl::FeatureIdentifier::visit(feature.id, ValueEvaluator());