[core] Introduce API to collect placed symbols data

The following methods are added to the `Renderer` class:
- `collectPlacedSymbolData()`
  enables or disables collecting of the placed symbols data

- `getPlacedSymbolsData()`
  if collecting of the placed symbols data is enabled, returns the
  reference to the `PlacedSymbolData` vector holding the collected data.

3 files changed, 21 insertions, 0 deletions

diff --git a/src/mbgl/renderer/render_orchestrator.cpp b/src/mbgl/renderer/render_orchestrator.cpp
index ae66e4ab42..ac62b71828 100644
--- a/src/mbgl/renderer/render_orchestrator.cpp
+++ b/src/mbgl/renderer/render_orchestrator.cpp
@@ -378,6 +378,7 @@ std::unique_ptr<RenderTree> RenderOrchestrator::createRenderTree(
         }
     }
     // Symbol placement.
+    assert((updateParameters->mode == MapMode::Tile) || !placedSymbolDataCollected);
     bool symbolBucketsChanged = false;
     bool symbolBucketsAdded = false;
     std::set<std::string> usedSymbolLayers;
@@ -425,6 +426,7 @@ std::unique_ptr<RenderTree> RenderOrchestrator::createRenderTree(
         renderTreeParameters->placementChanged = symbolBucketsChanged = !layersNeedPlacement.empty();
         if (renderTreeParameters->placementChanged) {
             Mutable<Placement> placement = Placement::create(updateParameters);
+            placement->collectPlacedSymbolData(placedSymbolDataCollected);
             placement->placeLayers(layersNeedPlacement);
             placementController.setPlacement(std::move(placement));
         }
@@ -635,6 +637,14 @@ void RenderOrchestrator::dumpDebugLogs() {
     imageManager->dumpDebugLogs();
 }
 
+void RenderOrchestrator::collectPlacedSymbolData(bool enable) {
+    placedSymbolDataCollected = enable;
+}
+
+const std::vector<PlacedSymbolData>& RenderOrchestrator::getPlacedSymbolsData() const {
+    return placementController.getPlacement()->getPlacedSymbolsData();
+}
+
 RenderLayer* RenderOrchestrator::getRenderLayer(const std::string& id) {
     auto it = renderLayers.find(id);
     return it != renderLayers.end() ? it->second.get() : nullptr;
diff --git a/src/mbgl/renderer/render_orchestrator.hpp b/src/mbgl/renderer/render_orchestrator.hpp
index 19632c3218..08904e7e5a 100644
--- a/src/mbgl/renderer/render_orchestrator.hpp
+++ b/src/mbgl/renderer/render_orchestrator.hpp
@@ -72,6 +72,8 @@ public:
 
     void reduceMemoryUse();
     void dumpDebugLogs();
+    void collectPlacedSymbolData(bool);
+    const std::vector<PlacedSymbolData>& getPlacedSymbolsData() const;
     void clearData();
 
 private:
@@ -124,6 +126,7 @@ private:
 
     const bool backgroundLayerAsColor;
     bool contextLost = false;
+    bool placedSymbolDataCollected = false;
 
     // Vectors with reserved capacity of layerImpls->size() to avoid reallocation
     // on each frame.
diff --git a/src/mbgl/renderer/renderer.cpp b/src/mbgl/renderer/renderer.cpp
index 0ec73671d1..ac9fac8990 100644
--- a/src/mbgl/renderer/renderer.cpp
+++ b/src/mbgl/renderer/renderer.cpp
@@ -125,6 +125,14 @@ void Renderer::dumpDebugLogs() {
     impl->orchestrator.dumpDebugLogs();
 }
 
+void Renderer::collectPlacedSymbolData(bool enable) {
+    impl->orchestrator.collectPlacedSymbolData(enable);
+}
+
+const std::vector<PlacedSymbolData>& Renderer::getPlacedSymbolsData() const {
+    return impl->orchestrator.getPlacedSymbolsData();
+}
+
 void Renderer::reduceMemoryUse() {
     gfx::BackendScope guard { impl->backend };
     impl->reduceMemoryUse();