[core] Introduce Placement::placeLayers()

src/mbgl/renderer/render_layer.hpp

@@ -146,4 +146,6 @@ private:
     bool hasRenderFailures = false;
 };
 
+using RenderLayerReferences = std::vector<std::reference_wrapper<RenderLayer>>;
+
 } // namespace mbgl

src/mbgl/renderer/render_orchestrator.cpp

@@ -62,7 +62,7 @@ public:
                    std::vector<std::unique_ptr<RenderItem>> sourceRenderItems_,
                    LineAtlas& lineAtlas_,
                    PatternAtlas& patternAtlas_,
-                   std::vector<std::reference_wrapper<RenderLayer>> layersNeedPlacement_,
+                   RenderLayerReferences layersNeedPlacement_,
                    Immutable<Placement> placement_,
                    bool updateSymbolOpacities_)
         : RenderTree(std::move(parameters_)),
@@ -96,7 +96,7 @@ public:
     std::vector<std::unique_ptr<RenderItem>> sourceRenderItems;
     std::reference_wrapper<LineAtlas> lineAtlas;
     std::reference_wrapper<PatternAtlas> patternAtlas;
-    std::vector<std::reference_wrapper<RenderLayer>> layersNeedPlacement;
+    RenderLayerReferences layersNeedPlacement;
     Immutable<Placement> placement;
     bool updateSymbolOpacities;
 };
@@ -379,15 +379,20 @@ std::unique_ptr<RenderTree> RenderOrchestrator::createRenderTree(
     }
     // Symbol placement.
     bool symbolBucketsChanged = false;
+    bool symbolBucketsAdded = false;
+    std::set<std::string> usedSymbolLayers;
     auto longitude = updateParameters->transformState.getLatLng().longitude();
-    if (isMapModeContinuous) {
-        bool symbolBucketsAdded = false;
-        for (auto it = layersNeedPlacement.crbegin(); it != layersNeedPlacement.crend(); ++it) {
-            auto result = crossTileSymbolIndex.addLayer(*it, longitude);
+    for (auto it = layersNeedPlacement.crbegin(); it != layersNeedPlacement.crend(); ++it) {
+        RenderLayer& layer = *it;
+        auto result = crossTileSymbolIndex.addLayer(layer, longitude);
+        if (isMapModeContinuous) {
+            usedSymbolLayers.insert(layer.getID());
             symbolBucketsAdded = symbolBucketsAdded || (result & CrossTileSymbolIndex::AddLayerResult::BucketsAdded);
             symbolBucketsChanged = symbolBucketsChanged || (result != CrossTileSymbolIndex::AddLayerResult::NoChanges);
         }
+    }
 
+    if (isMapModeContinuous) {
         optional<Duration> placementUpdatePeriodOverride;
         if (symbolBucketsAdded && !tiltedView) {
             // If the view is not tilted, we want *the new* symbols to show up faster, however simple setting
@@ -403,22 +408,14 @@ std::unique_ptr<RenderTree> RenderOrchestrator::createRenderTree(
             updateParameters->timePoint, updateParameters->transformState.getZoom(), placementUpdatePeriodOverride);
         symbolBucketsChanged |= renderTreeParameters->placementChanged;
 
-        std::set<std::string> usedSymbolLayers;
         if (renderTreeParameters->placementChanged) {
             Mutable<Placement> placement = makeMutable<Placement>(updateParameters, placementController.getPlacement());
-
-            for (auto it = layersNeedPlacement.crbegin(); it != layersNeedPlacement.crend(); ++it) {
-                const RenderLayer& layer = *it;
-                usedSymbolLayers.insert(layer.getID());
-                placement->placeLayer(layer);
-            }
-
-            placement->commit();
+            placement->placeLayers(layersNeedPlacement);
+            placementController.setPlacement(std::move(placement));
             crossTileSymbolIndex.pruneUnusedLayers(usedSymbolLayers);
             for (const auto& entry : renderSources) {
                 entry.second->updateFadingTiles();
             }
-            placementController.setPlacement(std::move(placement));
         } else {
             placementController.setPlacementStale();
         }
@@ -429,14 +426,10 @@ std::unique_ptr<RenderTree> RenderOrchestrator::createRenderTree(
         renderTreeParameters->placementChanged = symbolBucketsChanged = !layersNeedPlacement.empty();
         if (renderTreeParameters->placementChanged) {
             Mutable<Placement> placement = makeMutable<Placement>(updateParameters);
-            for (auto it = layersNeedPlacement.crbegin(); it != layersNeedPlacement.crend(); ++it) {
-                const RenderLayer& layer = *it;
-                crossTileSymbolIndex.addLayer(layer, longitude);
-                placement->placeLayer(layer);
-            }
-            placement->commit();
+            placement->placeLayers(layersNeedPlacement);
             placementController.setPlacement(std::move(placement));
         }
+        crossTileSymbolIndex.reset();
         renderTreeParameters->symbolFadeChange = 1.0f;
         renderTreeParameters->needsRepaint = false;
     }

src/mbgl/renderer/render_orchestrator.hpp

@@ -21,7 +21,6 @@ namespace mbgl {
 
 class RendererObserver;
 class RenderSource;
-class RenderLayer;
 class UpdateParameters;
 class RenderStaticData;
 class RenderedQueryOptions;
@@ -129,8 +128,8 @@ private:
     // Vectors with reserved capacity of layerImpls->size() to avoid reallocation
     // on each frame.
     std::vector<Immutable<style::LayerProperties>> filteredLayersForSource;
-    std::vector<std::reference_wrapper<RenderLayer>> orderedLayers;
-    std::vector<std::reference_wrapper<RenderLayer>> layersNeedPlacement;
+    RenderLayerReferences orderedLayers;
+    RenderLayerReferences layersNeedPlacement;
 };
 
 } // namespace mbgl

src/mbgl/text/placement.cpp

@@ -105,6 +105,13 @@ Placement::Placement(std::shared_ptr<const UpdateParameters> updateParameters_,
 
 Placement::Placement() : collisionIndex({}, MapMode::Static), collisionGroups(true) {}
 
+void Placement::placeLayers(const RenderLayerReferences& layers) {
+    for (auto it = layers.crbegin(); it != layers.crend(); ++it) {
+        placeLayer(*it);
+    }
+    commit();
+}
+
 void Placement::placeLayer(const RenderLayer& layer) {
     std::set<uint32_t> seenCrossTileIDs;
     for (const BucketPlacementData& data : layer.getPlacementData()) {

src/mbgl/text/placement.hpp

@@ -108,9 +108,7 @@ class Placement {
 public:
     Placement(std::shared_ptr<const UpdateParameters>, optional<Immutable<Placement>> prevPlacement = nullopt);
     Placement();
-
-    void placeLayer(const RenderLayer&);
-    void commit();
+    void placeLayers(const RenderLayerReferences&);
     void updateLayerBuckets(const RenderLayer&, const TransformState&, bool updateOpacities) const;
     float symbolFadeChange(TimePoint now) const;
     bool hasTransitions(TimePoint now) const;
@@ -128,6 +126,8 @@ public:
 private:
     friend SymbolBucket;
     void placeSymbolBucket(const BucketPlacementData&, std::set<uint32_t>& seenCrossTileIDs);
+    void placeLayer(const RenderLayer&);
+    void commit();
     // Returns `true` if bucket vertices were updated; returns `false` otherwise.
     bool updateBucketDynamicVertices(SymbolBucket&, const TransformState&, const RenderTile& tile) const;
     void updateBucketOpacities(SymbolBucket&, const TransformState&, std::set<uint32_t>&) const;