Annotation symbols should ignore icon placement

src/mbgl/annotation/annotation_manager.cpp

@@ -185,6 +185,7 @@ void AnnotationManager::updateStyle(Style& style) {
         layer->setSourceLayer(PointLayerID);
         layer->setIconImage({"{sprite}"});
         layer->setIconAllowOverlap(true);
+        layer->setIconIgnorePlacement(true);
 
         layer->impl->spriteAtlas = &spriteAtlas;
 

src/mbgl/text/collision_tile.cpp

@@ -20,7 +20,6 @@ CollisionTile::CollisionTile(PlacementConfig config_) : config(std::move(config_
         // bottom
         CollisionBox(Point<float>(0, util::EXTENT), -infinity, 0, infinity, 0, infinity),
     }}) {
-    tree.clear();
 
     // Compute the transformation matrix.
     const float angle_sin = std::sin(config.angle);
@@ -162,25 +161,32 @@ std::vector<IndexedSubfeature> CollisionTile::queryRenderedSymbols(const mapbox:
     CollisionBox queryBox(anchor, 0, 0, box.max.x - box.min.x, box.max.y - box.min.y, scale);
     auto predicates = bgi::intersects(getTreeBox(anchor, queryBox));
 
-    auto fn = [&] (const Tree& tree_) {
+    auto fn = [&] (const Tree& tree_, bool ignorePlacement) {
         for (auto it = tree_.qbegin(predicates); it != tree_.qend(); ++it) {
             const CollisionBox& blocking = std::get<1>(*it);
             const IndexedSubfeature& indexedFeature = std::get<2>(*it);
 
             auto& seenFeatures = sourceLayerFeatures[indexedFeature.sourceLayerName];
             if (seenFeatures.find(indexedFeature.index) == seenFeatures.end()) {
-                auto blockingAnchor = util::matrixMultiply(rotationMatrix, blocking.anchor);
-                float minPlacementScale = findPlacementScale(minScale, anchor, queryBox, blockingAnchor, blocking);
-                if (minPlacementScale >= scale) {
+                if (ignorePlacement) {
                     seenFeatures.insert(indexedFeature.index);
                     result.push_back(indexedFeature);
+                } else {
+                    auto blockingAnchor = util::matrixMultiply(rotationMatrix, blocking.anchor);
+                    float minPlacementScale = findPlacementScale(minScale, anchor, queryBox, blockingAnchor, blocking);
+                    if (minPlacementScale >= scale) {
+                        seenFeatures.insert(indexedFeature.index);
+                        result.push_back(indexedFeature);
+                    }
                 }
             }
         }
     };
 
-    fn(tree);
-    fn(ignoredTree);
+    bool ignorePlacement = false;
+    fn(tree, ignorePlacement);
+    ignorePlacement = true;
+    fn(ignoredTree, ignorePlacement);
 
     return result;
 }

test/api/annotations.test.cpp

@@ -341,3 +341,28 @@ TEST(Annotations, QueryRenderedFeatures) {
     EXPECT_TRUE(!!features2[0].id);
     EXPECT_EQ(*features2[0].id, 1);
 }
+
+TEST(Annotations, QueryFractionalZoomLevels) {
+    AnnotationTest test;
+
+    auto viewSize = test.view.getSize();
+    auto box = ScreenBox { {}, { double(viewSize[0]), double(viewSize[1]) } };
+
+    test.map.setStyleJSON(util::read_file("test/fixtures/api/empty.json"));
+    test.map.addAnnotationIcon("default_marker", namedMarker("default_marker.png"));
+
+    std::vector<mbgl::AnnotationID> ids;
+    for (int longitude = 0; longitude < 10; ++longitude) {
+        for (int latitude = 0; latitude < 10; ++latitude) {
+            ids.push_back(test.map.addAnnotation(SymbolAnnotation { { double(latitude), double(longitude) }, "default_marker" }));
+        }
+    }
+
+    test.map.setLatLngZoom({ 5, 5 }, 0);
+    for (uint16_t zoomSteps = 0; zoomSteps <= 20; ++zoomSteps) {
+        test.map.setZoom(zoomSteps / 10.0);
+        test::render(test.map);
+        auto features = test.map.queryRenderedFeatures(box);
+        EXPECT_EQ(features.size(), ids.size());
+    }
+}