Merge pull request #3 from AtlasProgramming/feature/2025-07-raw-bucket

Feature Collections

Author: AtlasProgramming

CMakeLists.txt

@@ -977,6 +977,10 @@ list(APPEND SRC_FILES
     ${PROJECT_SOURCE_DIR}/src/mbgl/plugin/plugin_layer_properties.cpp
     ${PROJECT_SOURCE_DIR}/src/mbgl/plugin/plugin_layer_impl.cpp
     ${PROJECT_SOURCE_DIR}/src/mbgl/plugin/plugin_layer_factory.cpp
+    ${PROJECT_SOURCE_DIR}/src/mbgl/plugin/feature_collection.hpp
+    ${PROJECT_SOURCE_DIR}/src/mbgl/plugin/feature_collection.cpp
+    ${PROJECT_SOURCE_DIR}/src/mbgl/plugin/feature_collection_bucket.hpp
+    ${PROJECT_SOURCE_DIR}/src/mbgl/plugin/feature_collection_bucket.cpp
 )
 
 

bazel/core.bzl

@@ -4,6 +4,8 @@ MLN_LAYER_PLUGIN_HEADERS = [
     "src/mbgl/plugin/plugin_layer_impl.hpp",
     "src/mbgl/plugin/plugin_layer_render.hpp",
     "src/mbgl/plugin/plugin_layer_properties.hpp",
+    "src/mbgl/plugin/feature_collection_bucket.hpp",
+    "src/mbgl/plugin/feature_collection.hpp",
 ]
 
 MLN_LAYER_PLUGIN_SOURCE = [
@@ -12,6 +14,8 @@ MLN_LAYER_PLUGIN_SOURCE = [
     "src/mbgl/plugin/plugin_layer_impl.cpp",
     "src/mbgl/plugin/plugin_layer_render.cpp",
     "src/mbgl/plugin/plugin_layer_properties.cpp",
+    "src/mbgl/plugin/feature_collection_bucket.cpp",
+    "src/mbgl/plugin/feature_collection.cpp",
 ]
 
 MLN_PUBLIC_GENERATED_STYLE_HEADERS = [

platform/darwin/app/PluginLayerExample.mm

@@ -1,21 +1,39 @@
 #import "PluginLayerExample.h"
 
+@interface PluginLayerExample () {
+
+}
+
+@property BOOL logFeatures;
+
+@end
+
+
 @implementation PluginLayerExample
 
 
 // This is the layer type in the style that is used
 +(MLNPluginLayerCapabilities *)layerCapabilities {
 
     MLNPluginLayerCapabilities *tempResult = [[MLNPluginLayerCapabilities alloc] init];
-    tempResult.layerID = @"plugin-layer-test";
+    tempResult.layerID = @"maplibre::filter_features";
     tempResult.requiresPass3D = YES;
+    tempResult.supportsReadingTileFeatures = YES;
     return tempResult;
 
 }
 
+-(id)init {
+    if (self = [super init]) {
+        self.logFeatures = NO;
+    }
+    return self;
+}
+
 // The overrides
--(void)onRenderLayer {
-    NSLog(@"PluginLayerExample: On Render Layer");
+-(void)onRenderLayer:(MLNMapView *)mapView
+       renderEncoder:(id<MTLRenderCommandEncoder>)renderEncoder {
+   //NSLog(@"PluginLayerExample: On Render Layer");
 
 }
 
@@ -24,7 +42,54 @@ -(void)onUpdateLayer {
 }
 
 -(void)onUpdateLayerProperties:(NSDictionary *)layerProperties {
-    // NSLog(@"Layer Properties: %@", layerProperties);
+  //  NSLog(@"Layer Properties: %@", layerProperties);
+}
+
+-(void)featureLoaded:(MLNPluginLayerTileFeature *)tileFeature {
+
+    // Writing a single string since the tile loading is multithreaded and the output can get interwoven
+    NSMutableString *outputStr = [NSMutableString string];
+    [outputStr appendFormat:@"Tile Feature (id:%@) Properties: %@\n", tileFeature.featureID, tileFeature.featureProperties];
+
+    for (NSValue *v in tileFeature.featureCoordinates) {
+
+        CLLocationCoordinate2D coord;
+        [v getValue:&coord];
+
+        [outputStr appendFormat:@"  -> (%f, %f) \n", coord.latitude, coord.longitude];
+
+    }
+
+    NSLog(@"Feature: %@", outputStr);
+}
+
+-(void)featureUnloaded:(MLNPluginLayerTileFeature *)tileFeature {
+   // NSLog(@"Tile Features Unloaded: %@", tileFeature.featureProperties);
+
+}
+
+
+- (void)onFeatureLoaded:(MLNPluginLayerTileFeature *)tileFeature {
+
+    [self featureLoaded:tileFeature];
+
+}
+
+/// Called when a set of features are loaded from the tile
+- (void)onFeatureCollectionLoaded:(MLNPluginLayerTileFeatureCollection *)tileFeatureCollection {
+    //NSLog(@"Feature Collection Loaded for tile: %@", tileFeatureCollection.tileID);
+    for (MLNPluginLayerTileFeature *feature in tileFeatureCollection.features) {
+        [self featureLoaded:feature];
+    }
+
+}
+
+/// Called when a set of features are unloaded because the tile goes out of scene/etc
+- (void)onFeatureCollectionUnloaded:(MLNPluginLayerTileFeatureCollection *)tileFeatureCollection {
+    //NSLog(@"Feature Collection Unloaded for tile: %@", tileFeatureCollection.tileID);
+    for (MLNPluginLayerTileFeature *feature in tileFeatureCollection.features) {
+        [self featureUnloaded:feature];
+    }
 }
 
 @end

platform/darwin/app/PluginLayerTestStyle.json

@@ -583,6 +583,13 @@
                 ]
             }
         },
+        {   "id": "centroid-features",
+            "type": "maplibre::filter_features",
+            "source": "maplibre",
+            "source-layer": "countries",
+            "maxzoom": 24,
+            "minzoom": 1
+        },
         {
             "id": "crimea-fill",
             "type": "fill",

platform/darwin/src/MLNPluginLayer.h

@@ -42,6 +42,22 @@ MLN_EXPORT
 
 @end
 
+@interface MLNPluginLayerTileFeature : NSObject
+
+// This is the unique feature ID in the tile source if applicable.  Can be empty
+@property NSString *featureID;
+@property NSDictionary *featureProperties;
+@property NSArray *featureCoordinates;
+
+@end
+
+@interface MLNPluginLayerTileFeatureCollection : NSObject
+
+@property NSArray *features;
+@property NSString *tileID;  // z,x,y
+
+@end
+
 typedef enum {
   MLNPluginLayerTileKindGeometry,
   MLNPluginLayerTileKindRaster,
@@ -55,6 +71,9 @@ MLN_EXPORT
 @property (copy) NSString *layerID;
 @property BOOL requiresPass3D;
 
+//! Set this to true if this layer can support reading features from the tiles
+@property BOOL supportsReadingTileFeatures;
+
 //! This is a list of layer properties that this layer supports.
 @property (copy) NSArray<MLNPluginLayerProperty *> *layerProperties;
 
@@ -104,6 +123,19 @@ MLN_EXPORT
 /// dynamic properties are updated
 - (void)onUpdateLayerProperties:(NSDictionary *)layerProperties;
 
+/// Called when a feature is loaded from the tile
+- (void)onFeatureLoaded:(MLNPluginLayerTileFeature *)tileFeature;
+
+/// Called when a set of features are loaded from the tile
+/*
+ TODO: Think about returning that this layer doesn't care about this feature collection via a
+ bool/etc and then the underlying layer won't have to track this collection.
+ */
+- (void)onFeatureCollectionLoaded:(MLNPluginLayerTileFeatureCollection *)tileFeatureCollection;
+
+/// Called when a set of features are unloaded because the tile goes out of scene/etc
+- (void)onFeatureCollectionUnloaded:(MLNPluginLayerTileFeatureCollection *)tileFeatureCollection;
+
 /// Added to a map view
 - (void)didMoveToMapView:(MLNMapView *)mapView;
 

platform/darwin/src/MLNPluginLayer.mm

@@ -1,5 +1,13 @@
 #import "MLNPluginLayer.h"
 
+@implementation MLNPluginLayerTileFeature
+
+@end
+
+@implementation MLNPluginLayerTileFeatureCollection
+
+@end
+
 @implementation MLNPluginLayerProperty
 
 +(MLNPluginLayerProperty *)propertyWithName:(NSString *)propertyName
@@ -66,12 +74,31 @@ -(void)onUpdateLayerProperties:(NSDictionary *)layerProperties {
     // Base class does nothing
 }
 
+// If the layer properties indicate that this layer has a the ability to intercept
+// features, then this method will be called when a feature is loaded
+- (void)onFeatureLoaded:(MLNPluginLayerTileFeature *)tileFeature {
+    // Base class does nothing
+}
+
+// If the layer properties indicate that this layer has a the ability to intercept
+// features, then this method will be called when a feature is loaded
+- (void)onFeatureCollectionLoaded:(MLNPluginLayerTileFeatureCollection *)tileFeatureCollection {
+    // Base class does nothing
+}
+
+/// Called when a set of features are unloaded because the tile goes out of scene/etc
+- (void)onFeatureCollectionUnloaded:(MLNPluginLayerTileFeatureCollection *)tileFeatureCollection {
+    // Base class does nothing
+}
+
+
 /// Added to a map view
 - (void)didMoveToMapView:(MLNMapView *)mapView {
     // Base class does nothing
 }
 
 
+
 @end
 
 

platform/ios/app/MBXViewController.mm

@@ -2332,17 +2332,18 @@ - (void)setStyles
 
 
 
-
-    /// Style that does not require an `apiKey` nor any further configuration
-    [self.styleNames addObject:@"MapLibre Basic"];
-    [self.styleURLs addObject:[NSURL URLWithString:@"https://demotiles.maplibre.org/style.json"]];
-
     /// This is hte same style as above but copied locally and the three instances of the metal plug-in layer added to the style
     /// Look for "type": "plugin-layer-metal-rendering" in the PluginLayerTestStyle.json for an example of how the layer is defined
     [self.styleNames addObject:@"MapLibre Basic - Local With Plugin"];
     NSURL *url = [[NSBundle mainBundle] URLForResource:@"PluginLayerTestStyle.json" withExtension:nil];
     [self.styleURLs addObject:url];
 
+
+    /// Style that does not require an `apiKey` nor any further configuration
+    [self.styleNames addObject:@"MapLibre Basic"];
+    [self.styleURLs addObject:[NSURL URLWithString:@"https://demotiles.maplibre.org/style.json"]];
+
+
     /// Add MapLibre Styles if an `apiKey` exists
     NSString* apiKey = [MLNSettings apiKey];
     if (apiKey.length)