[core] simplify dependency layout process and refactor data structures

4 files changed, 78 insertions, 17 deletions

diff --git a/src/mbgl/layout/layout.hpp b/src/mbgl/layout/layout.hpp
new file mode 100644
index 0000000000..de2d28728f
--- /dev/null
+++ b/src/mbgl/layout/layout.hpp
@@ -0,0 +1,36 @@
+#pragma once
+
+#include <mbgl/style/layer_type.hpp>
+#include <mbgl/renderer/image_atlas.hpp>
+#include <mbgl/text/glyph_atlas.hpp>
+#include <memory>
+
+namespace mbgl {
+
+class Bucket;
+class BucketParameters;
+class RenderLayer;
+class FeatureIndex;
+
+class Layout {
+public:
+    Layout() = default;
+    virtual ~Layout() = default;
+
+    virtual void createBucket(const ImagePositions&,
+                              std::unique_ptr<FeatureIndex>&,
+                              std::unordered_map<std::string, std::shared_ptr<Bucket>>&,
+                              const bool,
+                              const bool) = 0;
+
+    virtual void prepareSymbols(const GlyphMap&, const GlyphPositions&,
+                                const ImageMap&, const ImagePositions&) {};
+
+    virtual bool hasSymbolInstances() const {
+        return true;
+    };
+    
+    virtual bool hasDependencies() const = 0;
+};
+
+} // namespace mbgl
diff --git a/src/mbgl/layout/pattern_layout.hpp b/src/mbgl/layout/pattern_layout.hpp
index 9f4964ca6b..0ffac36b75 100644
--- a/src/mbgl/layout/pattern_layout.hpp
+++ b/src/mbgl/layout/pattern_layout.hpp
@@ -1,4 +1,5 @@
 #pragma once
+#include <mbgl/layout/layout.hpp>
 #include <mbgl/renderer/bucket_parameters.hpp>
 #include <mbgl/geometry/feature_index.hpp>
 #include <mbgl/renderer/render_layer.hpp>
@@ -22,13 +23,14 @@ public:
 };
 
 template <class B>
-class PatternLayout {
+class PatternLayout : public Layout {
 public:
     PatternLayout(const BucketParameters& parameters,
                   const std::vector<const RenderLayer*>& layers,
                   std::unique_ptr<GeometryTileLayer> sourceLayer_,
                   ImageDependencies& patternDependencies)
-                  : bucketLeaderID(layers.at(0)->getID()),
+                  : Layout(),
+                    bucketLeaderID(layers.at(0)->getID()),
                     sourceLayer(std::move(sourceLayer_)),
                     zoom(parameters.tileID.overscaledZ),
                     overscaling(parameters.tileID.overscaleFactor()),
@@ -90,12 +92,14 @@ public:
         }
     };
 
-    bool pattern() {
+    ~PatternLayout() final = default;
+
+    bool hasDependencies() const override {
         return hasPattern;
     }
 
-    std::unique_ptr<B> createBucket(const ImagePositions& patternPositions, std::unique_ptr<FeatureIndex>& featureIndex) {
-        auto bucket = std::make_unique<B>(layout, layerPaintProperties, zoom, overscaling);
+    void createBucket(const ImagePositions& patternPositions, std::unique_ptr<FeatureIndex>& featureIndex, std::unordered_map<std::string, std::shared_ptr<Bucket>>& buckets, const bool, const bool) override {
+        auto bucket = std::make_shared<B>(layout, layerPaintProperties, zoom, overscaling);
         for (auto & patternFeature : features) {
             const auto i = patternFeature.i;
             std::unique_ptr<GeometryTileFeature> feature = std::move(patternFeature.feature);
@@ -105,7 +109,11 @@ public:
             bucket->addFeature(*feature, geometries, patternPositions, patterns);
             featureIndex->insert(geometries, i, sourceLayerID, groupID);
         }
-        return bucket;
+        if (bucket->hasData()) {
+            for (const auto& pair : layerPaintProperties) {
+                buckets.emplace(pair.first, bucket);
+            }
+        }
     };
 
     std::map<std::string, typename B::PossiblyEvaluatedPaintProperties> layerPaintProperties;
diff --git a/src/mbgl/layout/symbol_layout.cpp b/src/mbgl/layout/symbol_layout.cpp
index fd4dd2bedd..344a76bbe9 100644
--- a/src/mbgl/layout/symbol_layout.cpp
+++ b/src/mbgl/layout/symbol_layout.cpp
@@ -1,3 +1,4 @@
+#include <mbgl/layout/layout.hpp>
 #include <mbgl/layout/symbol_layout.hpp>
 #include <mbgl/layout/merge_lines.hpp>
 #include <mbgl/layout/clip_lines.hpp>
@@ -40,7 +41,8 @@ SymbolLayout::SymbolLayout(const BucketParameters& parameters,
                            std::unique_ptr<GeometryTileLayer> sourceLayer_,
                            ImageDependencies& imageDependencies,
                            GlyphDependencies& glyphDependencies)
-    : bucketLeaderID(layers.at(0)->getID()),
+    : Layout(),
+      bucketLeaderID(layers.at(0)->getID()),
       sourceLayer(std::move(sourceLayer_)),
       overscaling(parameters.tileID.overscaleFactor()),
       zoom(parameters.tileID.overscaledZ),
@@ -149,11 +151,15 @@ SymbolLayout::SymbolLayout(const BucketParameters& parameters,
     }
 }
 
+bool SymbolLayout::hasDependencies() const {
+    return features.size() != 0;
+}
+
 bool SymbolLayout::hasSymbolInstances() const {
     return !symbolInstances.empty();
 }
 
-void SymbolLayout::prepare(const GlyphMap& glyphMap, const GlyphPositions& glyphPositions,
+void SymbolLayout::prepareSymbols(const GlyphMap& glyphMap, const GlyphPositions& glyphPositions,
                            const ImageMap& imageMap, const ImagePositions& imagePositions) {
     const bool textAlongLine = layout.get<TextRotationAlignment>() == AlignmentType::Map &&
         layout.get<SymbolPlacement>() != SymbolPlacementType::Point;
@@ -394,11 +400,11 @@ std::vector<float> CalculateTileDistances(const GeometryCoordinates& line, const
     return tileDistances;
 }
 
-std::unique_ptr<SymbolBucket> SymbolLayout::place(const bool showCollisionBoxes) {
+void SymbolLayout::createBucket(const ImagePositions&, std::unique_ptr<FeatureIndex>&, std::unordered_map<std::string, std::shared_ptr<Bucket>>& buckets, const bool firstLoad, const bool showCollisionBoxes) {
     const bool mayOverlap = layout.get<TextAllowOverlap>() || layout.get<IconAllowOverlap>() ||
         layout.get<TextIgnorePlacement>() || layout.get<IconIgnorePlacement>();
     
-    auto bucket = std::make_unique<SymbolBucket>(layout, layerPaintProperties, textSize, iconSize, zoom, sdfIcons, iconsNeedLinear, mayOverlap, bucketLeaderID, std::move(symbolInstances));
+    auto bucket = std::make_shared<SymbolBucket>(layout, layerPaintProperties, textSize, iconSize, zoom, sdfIcons, iconsNeedLinear, mayOverlap, bucketLeaderID, std::move(symbolInstances));
 
     for (SymbolInstance &symbolInstance : bucket->symbolInstances) {
 
@@ -469,8 +475,15 @@ std::unique_ptr<SymbolBucket> SymbolLayout::place(const bool showCollisionBoxes)
     if (showCollisionBoxes) {
         addToDebugBuffers(*bucket);
     }
+    if (bucket->hasData()){
+        for (const auto& pair : layerPaintProperties) {
+            if (!firstLoad) {
+                bucket->justReloaded = true;
+            }
+            buckets.emplace(pair.first, bucket);
+        }
+    }
 
-    return bucket;
 }
 
 template <typename Buffer>
diff --git a/src/mbgl/layout/symbol_layout.hpp b/src/mbgl/layout/symbol_layout.hpp
index 43b577859f..b866703e6c 100644
--- a/src/mbgl/layout/symbol_layout.hpp
+++ b/src/mbgl/layout/symbol_layout.hpp
@@ -1,5 +1,6 @@
 #pragma once
 
+#include <mbgl/layout/layout.hpp>
 #include <mbgl/map/mode.hpp>
 #include <mbgl/style/layers/symbol_layer_properties.hpp>
 #include <mbgl/layout/symbol_feature.hpp>
@@ -25,20 +26,23 @@ namespace style {
 class Filter;
 } // namespace style
 
-class SymbolLayout {
+class SymbolLayout : public Layout {
 public:
     SymbolLayout(const BucketParameters&,
                  const std::vector<const RenderLayer*>&,
                  std::unique_ptr<GeometryTileLayer>,
                  ImageDependencies&,
                  GlyphDependencies&);
+    
+    ~SymbolLayout() final = default;
 
-    void prepare(const GlyphMap&, const GlyphPositions&,
-                 const ImageMap&, const ImagePositions&);
+    void prepareSymbols(const GlyphMap&, const GlyphPositions&,
+                 const ImageMap&, const ImagePositions&) override;
 
-    std::unique_ptr<SymbolBucket> place(const bool showCollisionBoxes);
+    void createBucket(const ImagePositions&, std::unique_ptr<FeatureIndex>&, std::unordered_map<std::string, std::shared_ptr<Bucket>>&, const bool firstLoad, const bool showCollisionBoxes) override;
 
-    bool hasSymbolInstances() const;
+    bool hasSymbolInstances() const override;
+    bool hasDependencies() const override;
 
     std::map<std::string,
         std::pair<style::IconPaintProperties::PossiblyEvaluated, style::TextPaintProperties::PossiblyEvaluated>> layerPaintProperties;
@@ -81,7 +85,7 @@ private:
 
     bool sdfIcons = false;
     bool iconsNeedLinear = false;
-    
+
     style::TextSize::UnevaluatedType textSize;
     style::IconSize::UnevaluatedType iconSize;