[core][Android][Darwin] LayerManager creates RenderLayer instances

`LayerManager` is now responsible for `RenderLayer` instances creation,
so that there is a single entry point for creating of objects, which
correspond to a certain layer type.

The `LayerType type` field is dropped from `Layer::Impl`.

15 files changed, 17 insertions, 64 deletions

diff --git a/src/mbgl/renderer/group_by_layout.cpp b/src/mbgl/renderer/group_by_layout.cpp
index 3b02727ff8..41a895902c 100644
--- a/src/mbgl/renderer/group_by_layout.cpp
+++ b/src/mbgl/renderer/group_by_layout.cpp
@@ -18,7 +18,7 @@ std::string layoutKey(const RenderLayer& layer) {
     rapidjson::Writer<rapidjson::StringBuffer> writer(s);
 
     writer.StartArray();
-    writer.Uint(static_cast<uint32_t>(layer.type));
+    writer.Uint64(reinterpret_cast<uint64_t>(layer.baseImpl->getTypeInfo()));
     writer.String(layer.baseImpl->source);
     writer.String(layer.baseImpl->sourceLayer);
     writer.Double(layer.baseImpl->minZoom);
diff --git a/src/mbgl/renderer/layers/render_background_layer.cpp b/src/mbgl/renderer/layers/render_background_layer.cpp
index 3e510ef352..d7bf0dc6bd 100644
--- a/src/mbgl/renderer/layers/render_background_layer.cpp
+++ b/src/mbgl/renderer/layers/render_background_layer.cpp
@@ -14,7 +14,7 @@ namespace mbgl {
 using namespace style;
 
 RenderBackgroundLayer::RenderBackgroundLayer(Immutable<style::BackgroundLayer::Impl> _impl)
-    : RenderLayer(style::LayerType::Background, _impl),
+    : RenderLayer(std::move(_impl)),
       unevaluated(impl().paint.untransitioned()) {
 }
 
diff --git a/src/mbgl/renderer/layers/render_circle_layer.cpp b/src/mbgl/renderer/layers/render_circle_layer.cpp
index 46db06416d..b984c596d3 100644
--- a/src/mbgl/renderer/layers/render_circle_layer.cpp
+++ b/src/mbgl/renderer/layers/render_circle_layer.cpp
@@ -15,7 +15,7 @@ namespace mbgl {
 using namespace style;
 
 RenderCircleLayer::RenderCircleLayer(Immutable<style::CircleLayer::Impl> _impl)
-    : RenderLayer(style::LayerType::Circle, _impl),
+    : RenderLayer(std::move(_impl)),
       unevaluated(impl().paint.untransitioned()) {
 }
 
diff --git a/src/mbgl/renderer/layers/render_custom_layer.cpp b/src/mbgl/renderer/layers/render_custom_layer.cpp
index e80ceda6c7..9e65830faf 100644
--- a/src/mbgl/renderer/layers/render_custom_layer.cpp
+++ b/src/mbgl/renderer/layers/render_custom_layer.cpp
@@ -13,7 +13,7 @@ namespace mbgl {
 using namespace style;
 
 RenderCustomLayer::RenderCustomLayer(Immutable<style::CustomLayer::Impl> _impl)
-    : RenderLayer(LayerType::Custom, _impl), host(_impl->host) {
+    : RenderLayer(std::move(_impl)), host(impl().host) {
     assert(BackendScope::exists());
     host->initialize();
 }
diff --git a/src/mbgl/renderer/layers/render_fill_extrusion_layer.cpp b/src/mbgl/renderer/layers/render_fill_extrusion_layer.cpp
index 8f1b961d1a..91d58bf8d6 100644
--- a/src/mbgl/renderer/layers/render_fill_extrusion_layer.cpp
+++ b/src/mbgl/renderer/layers/render_fill_extrusion_layer.cpp
@@ -19,7 +19,7 @@ namespace mbgl {
 using namespace style;
 
 RenderFillExtrusionLayer::RenderFillExtrusionLayer(Immutable<style::FillExtrusionLayer::Impl> _impl)
-    : RenderLayer(style::LayerType::FillExtrusion, _impl),
+    : RenderLayer(std::move(_impl)),
       unevaluated(impl().paint.untransitioned()) {
 }
 
diff --git a/src/mbgl/renderer/layers/render_fill_layer.cpp b/src/mbgl/renderer/layers/render_fill_layer.cpp
index 83be3ccd57..391c2d5b0f 100644
--- a/src/mbgl/renderer/layers/render_fill_layer.cpp
+++ b/src/mbgl/renderer/layers/render_fill_layer.cpp
@@ -17,7 +17,7 @@ namespace mbgl {
 using namespace style;
 
 RenderFillLayer::RenderFillLayer(Immutable<style::FillLayer::Impl> _impl)
-    : RenderLayer(style::LayerType::Fill, _impl),
+    : RenderLayer(std::move(_impl)),
       unevaluated(impl().paint.untransitioned()) {
 }
 
diff --git a/src/mbgl/renderer/layers/render_heatmap_layer.cpp b/src/mbgl/renderer/layers/render_heatmap_layer.cpp
index 4e5e890358..1842cdac93 100644
--- a/src/mbgl/renderer/layers/render_heatmap_layer.cpp
+++ b/src/mbgl/renderer/layers/render_heatmap_layer.cpp
@@ -17,7 +17,7 @@ namespace mbgl {
 using namespace style;
 
 RenderHeatmapLayer::RenderHeatmapLayer(Immutable<style::HeatmapLayer::Impl> _impl)
-    : RenderLayer(style::LayerType::Heatmap, _impl),
+    : RenderLayer(std::move(_impl)),
     unevaluated(impl().paint.untransitioned()), colorRamp({256, 1}) {
 }
 
diff --git a/src/mbgl/renderer/layers/render_hillshade_layer.cpp b/src/mbgl/renderer/layers/render_hillshade_layer.cpp
index 835cb3f9f9..ba7e782f16 100644
--- a/src/mbgl/renderer/layers/render_hillshade_layer.cpp
+++ b/src/mbgl/renderer/layers/render_hillshade_layer.cpp
@@ -16,7 +16,7 @@ namespace mbgl {
 
 using namespace style;
 RenderHillshadeLayer::RenderHillshadeLayer(Immutable<style::HillshadeLayer::Impl> _impl)
-    : RenderLayer(style::LayerType::Hillshade, _impl),
+    : RenderLayer(std::move(_impl)),
       unevaluated(impl().paint.untransitioned()) {
 }
 
diff --git a/src/mbgl/renderer/layers/render_line_layer.cpp b/src/mbgl/renderer/layers/render_line_layer.cpp
index 94081b5f09..fcdbc0b47a 100644
--- a/src/mbgl/renderer/layers/render_line_layer.cpp
+++ b/src/mbgl/renderer/layers/render_line_layer.cpp
@@ -18,7 +18,7 @@ namespace mbgl {
 using namespace style;
 
 RenderLineLayer::RenderLineLayer(Immutable<style::LineLayer::Impl> _impl)
-    : RenderLayer(style::LayerType::Line, _impl),
+    : RenderLayer(std::move(_impl)),
       unevaluated(impl().paint.untransitioned()),
       colorRamp({256, 1}) {
 }
diff --git a/src/mbgl/renderer/layers/render_raster_layer.cpp b/src/mbgl/renderer/layers/render_raster_layer.cpp
index 8e0651b65b..e0a7e427ad 100644
--- a/src/mbgl/renderer/layers/render_raster_layer.cpp
+++ b/src/mbgl/renderer/layers/render_raster_layer.cpp
@@ -14,7 +14,7 @@ namespace mbgl {
 using namespace style;
 
 RenderRasterLayer::RenderRasterLayer(Immutable<style::RasterLayer::Impl> _impl)
-    : RenderLayer(style::LayerType::Raster, _impl),
+    : RenderLayer(std::move(_impl)),
       unevaluated(impl().paint.untransitioned()) {
 }
 
diff --git a/src/mbgl/renderer/layers/render_symbol_layer.cpp b/src/mbgl/renderer/layers/render_symbol_layer.cpp
index 2b3a7195c5..11ffd74b10 100644
--- a/src/mbgl/renderer/layers/render_symbol_layer.cpp
+++ b/src/mbgl/renderer/layers/render_symbol_layer.cpp
@@ -23,7 +23,7 @@ namespace mbgl {
 using namespace style;
 
 RenderSymbolLayer::RenderSymbolLayer(Immutable<style::SymbolLayer::Impl> _impl)
-    : RenderLayer(style::LayerType::Symbol, _impl),
+    : RenderLayer(std::move(_impl)),
       unevaluated(impl().paint.untransitioned()) {
 }
 
diff --git a/src/mbgl/renderer/render_layer.cpp b/src/mbgl/renderer/render_layer.cpp
index 3e9a7caf24..033df02282 100644
--- a/src/mbgl/renderer/render_layer.cpp
+++ b/src/mbgl/renderer/render_layer.cpp
@@ -1,14 +1,4 @@
 #include <mbgl/renderer/render_layer.hpp>
-#include <mbgl/renderer/layers/render_background_layer.hpp>
-#include <mbgl/renderer/layers/render_circle_layer.hpp>
-#include <mbgl/renderer/layers/render_custom_layer.hpp>
-#include <mbgl/renderer/layers/render_fill_extrusion_layer.hpp>
-#include <mbgl/renderer/layers/render_fill_layer.hpp>
-#include <mbgl/renderer/layers/render_hillshade_layer.hpp>
-#include <mbgl/renderer/layers/render_line_layer.hpp>
-#include <mbgl/renderer/layers/render_raster_layer.hpp>
-#include <mbgl/renderer/layers/render_symbol_layer.hpp>
-#include <mbgl/renderer/layers/render_heatmap_layer.hpp>
 #include <mbgl/renderer/paint_parameters.hpp>
 #include <mbgl/renderer/render_tile.hpp>
 #include <mbgl/style/types.hpp>
@@ -19,42 +9,12 @@ namespace mbgl {
 
 using namespace style;
 
-std::unique_ptr<RenderLayer> RenderLayer::create(Immutable<Layer::Impl> impl) {
-    switch (impl->type) {
-    case LayerType::Fill:
-        return std::make_unique<RenderFillLayer>(staticImmutableCast<FillLayer::Impl>(impl));
-    case LayerType::Line:
-        return std::make_unique<RenderLineLayer>(staticImmutableCast<LineLayer::Impl>(impl));
-    case LayerType::Circle:
-        return std::make_unique<RenderCircleLayer>(staticImmutableCast<CircleLayer::Impl>(impl));
-    case LayerType::Symbol:
-        return std::make_unique<RenderSymbolLayer>(staticImmutableCast<SymbolLayer::Impl>(impl));
-    case LayerType::Raster:
-        return std::make_unique<RenderRasterLayer>(staticImmutableCast<RasterLayer::Impl>(impl));
-    case LayerType::Hillshade:
-        return std::make_unique<RenderHillshadeLayer>(staticImmutableCast<HillshadeLayer::Impl>(impl));
-    case LayerType::Background:
-        return std::make_unique<RenderBackgroundLayer>(staticImmutableCast<BackgroundLayer::Impl>(impl));
-    case LayerType::Custom:
-        return std::make_unique<RenderCustomLayer>(staticImmutableCast<CustomLayer::Impl>(impl));
-    case LayerType::FillExtrusion:
-        return std::make_unique<RenderFillExtrusionLayer>(staticImmutableCast<FillExtrusionLayer::Impl>(impl));
-    case LayerType::Heatmap:
-        return std::make_unique<RenderHeatmapLayer>(staticImmutableCast<HeatmapLayer::Impl>(impl));
-    }
-
-    // Not reachable, but placate GCC.
-    assert(false);
-    return nullptr;
-}
-
-RenderLayer::RenderLayer(style::LayerType type_, Immutable<style::Layer::Impl> baseImpl_)
-        : type(type_),
-          baseImpl(baseImpl_) {
+RenderLayer::RenderLayer(Immutable<style::Layer::Impl> baseImpl_)
+    : baseImpl(std::move(baseImpl_)) {
 }
 
 void RenderLayer::setImpl(Immutable<style::Layer::Impl> impl) {
-    baseImpl = impl;
+    baseImpl = std::move(impl);
 }
 
 const std::string& RenderLayer::getID() const {
diff --git a/src/mbgl/renderer/render_layer.hpp b/src/mbgl/renderer/render_layer.hpp
index a92d8f5aff..4e0e1913b6 100644
--- a/src/mbgl/renderer/render_layer.hpp
+++ b/src/mbgl/renderer/render_layer.hpp
@@ -23,13 +23,9 @@ class TransformState;
 
 class RenderLayer {
 protected:
-    RenderLayer(style::LayerType, Immutable<style::Layer::Impl>);
-
-    const style::LayerType type;
+    RenderLayer(Immutable<style::Layer::Impl>);
 
 public:
-    static std::unique_ptr<RenderLayer> create(Immutable<style::Layer::Impl>);
-
     virtual ~RenderLayer() = default;
 
     // Begin transitions for any properties that have changed since the last frame.
@@ -93,8 +89,6 @@ public:
     // TODO: Only for background layers.
     virtual optional<Color> getSolidBackground() const;
 
-    friend std::string layoutKey(const RenderLayer&);
-
 protected:
     // Checks whether the current hardware can render this layer. If it can't, we'll show a warning
     // in the console to inform the developer.
diff --git a/src/mbgl/renderer/renderer_impl.cpp b/src/mbgl/renderer/renderer_impl.cpp
index 32fcd57332..c4c4851345 100644
--- a/src/mbgl/renderer/renderer_impl.cpp
+++ b/src/mbgl/renderer/renderer_impl.cpp
@@ -164,7 +164,7 @@ void Renderer::Impl::render(const UpdateParameters& updateParameters) {
 
     // Create render layers for newly added layers.
     for (const auto& entry : layerDiff.added) {
-        renderLayers.emplace(entry.first, RenderLayer::create(entry.second));
+        renderLayers.emplace(entry.first, LayerManager::get()->createRenderLayer(entry.second));
     }
 
     // Update render layers for changed layers.
diff --git a/src/mbgl/renderer/style_diff.cpp b/src/mbgl/renderer/style_diff.cpp
index 0017280310..270c4483cd 100644
--- a/src/mbgl/renderer/style_diff.cpp
+++ b/src/mbgl/renderer/style_diff.cpp
@@ -62,8 +62,7 @@ SourceDifference diffSources(const Immutable<std::vector<ImmutableSource>>& a,
 LayerDifference diffLayers(const Immutable<std::vector<ImmutableLayer>>& a,
                            const Immutable<std::vector<ImmutableLayer>>& b) {
     return diff(a, b, [] (const ImmutableLayer& lhs, const ImmutableLayer& rhs) {
-        return std::tie(lhs->id, lhs->type)
-            == std::tie(rhs->id, rhs->type);
+        return (lhs->id == rhs->id) && (lhs->getTypeInfo() == rhs->getTypeInfo());
     });
 }