[core] Remove casts for Custom and Background render layers

5 files changed, 26 insertions, 15 deletions

diff --git a/src/mbgl/renderer/layers/render_background_layer.cpp b/src/mbgl/renderer/layers/render_background_layer.cpp
index f20bd7ae5e..3e510ef352 100644
--- a/src/mbgl/renderer/layers/render_background_layer.cpp
+++ b/src/mbgl/renderer/layers/render_background_layer.cpp
@@ -123,4 +123,12 @@ void RenderBackgroundLayer::render(PaintParameters& parameters, RenderSource*) {
     }
 }
 
+optional<Color> RenderBackgroundLayer::getSolidBackground() const {
+    if (!evaluated.get<BackgroundPattern>().from.empty()) {
+        return nullopt;
+    }
+
+    return { evaluated.get<BackgroundColor>() * evaluated.get<BackgroundOpacity>() };
+}
+
 } // namespace mbgl
diff --git a/src/mbgl/renderer/layers/render_background_layer.hpp b/src/mbgl/renderer/layers/render_background_layer.hpp
index 854c077a62..fef9ad97b4 100644
--- a/src/mbgl/renderer/layers/render_background_layer.hpp
+++ b/src/mbgl/renderer/layers/render_background_layer.hpp
@@ -15,6 +15,7 @@ public:
     void evaluate(const PropertyEvaluationParameters&) override;
     bool hasTransition() const override;
     bool hasCrossfade() const override;
+    optional<Color> getSolidBackground() const final;
     void render(PaintParameters&, RenderSource*) override;
 
     std::unique_ptr<Bucket> createBucket(const BucketParameters&, const std::vector<const RenderLayer*>&) const override;
diff --git a/src/mbgl/renderer/render_layer.cpp b/src/mbgl/renderer/render_layer.cpp
index 71c7c54834..efd890eda8 100644
--- a/src/mbgl/renderer/render_layer.cpp
+++ b/src/mbgl/renderer/render_layer.cpp
@@ -90,6 +90,10 @@ void RenderLayer::update() {
     // no-op
 }
 
+optional<Color> RenderLayer::getSolidBackground() const {
+    return nullopt;
+}
+
 RenderLayer::RenderTiles RenderLayer::filterRenderTiles(RenderTiles tiles, FilterFunctionPtr filterFn) const {
     assert(filterFn != nullptr);
     RenderTiles filtered;
diff --git a/src/mbgl/renderer/render_layer.hpp b/src/mbgl/renderer/render_layer.hpp
index dc7c58adeb..b335a468b0 100644
--- a/src/mbgl/renderer/render_layer.hpp
+++ b/src/mbgl/renderer/render_layer.hpp
@@ -101,6 +101,9 @@ public:
     // similar to color ramp. Temporarily moved to the base.
     virtual void update();
 
+    // TODO: Only for background layers.
+    virtual optional<Color> getSolidBackground() const;
+
     friend std::string layoutKey(const RenderLayer&);
 
 protected:
diff --git a/src/mbgl/renderer/renderer_impl.cpp b/src/mbgl/renderer/renderer_impl.cpp
index 4c25104e43..124c16cb64 100644
--- a/src/mbgl/renderer/renderer_impl.cpp
+++ b/src/mbgl/renderer/renderer_impl.cpp
@@ -218,9 +218,9 @@ void Renderer::Impl::render(const UpdateParameters& updateParameters) {
         bool needsRelayout = false;
 
         for (const auto& layer : *layerImpls) {
-            if (layer->type == LayerType::Background ||
-                layer->type == LayerType::Custom ||
-                layer->source != source->id) {
+
+            if (layer->getTypeInfo()->source == LayerTypeInfo::Source::NotRequired
+                    || layer->source != source->id) {
                 continue;
             }
 
@@ -298,21 +298,16 @@ void Renderer::Impl::render(const UpdateParameters& updateParameters) {
             continue;
         }
 
-        if (const RenderBackgroundLayer* background = layer->as<RenderBackgroundLayer>()) {
-            const BackgroundPaintProperties::PossiblyEvaluated& paint = background->evaluated;
-            if (parameters.contextMode == GLContextMode::Unique
-                    && layerImpl.get() == layerImpls->at(0).get()
-                    && paint.get<BackgroundPattern>().from.empty()) {
-                // This is a solid background. We can use glClear().
-                backgroundColor = paint.get<BackgroundColor>() * paint.get<BackgroundOpacity>();
-            } else {
-                // This is a textured background, or not the bottommost layer. We need to render it with a quad.
-                order.emplace_back(RenderItem { *layer, nullptr });
+        if (parameters.contextMode == GLContextMode::Unique
+            && layerImpl.get() == layerImpls->at(0).get()) {
+            const auto& solidBackground = layer->getSolidBackground();
+            if (solidBackground) {
+                backgroundColor = *solidBackground;
+                continue;
             }
-            continue;
         }
 
-        if (layer->is<RenderCustomLayer>()) {
+        if (layerImpl->getTypeInfo()->source == LayerTypeInfo::Source::NotRequired) {
             order.emplace_back(RenderItem { *layer, nullptr });
             continue;
         }