[core] Render fill-extrusion layers (#8431)

1 files changed, 7 insertions, 68 deletions

diff --git a/src/mbgl/style/paint_property.hpp b/src/mbgl/style/paint_property.hpp
index 7f7018748c..dd8d6c0b50 100644
--- a/src/mbgl/style/paint_property.hpp
+++ b/src/mbgl/style/paint_property.hpp
@@ -1,5 +1,6 @@
 #pragma once
 
+#include <mbgl/style/transitioning_property.hpp>
 #include <mbgl/style/class_dictionary.hpp>
 #include <mbgl/style/property_value.hpp>
 #include <mbgl/style/data_driven_property_value.hpp>
@@ -24,68 +25,6 @@ class GeometryTileFeature;
 namespace style {
 
 template <class Value>
-class UnevaluatedPaintProperty {
-public:
-    UnevaluatedPaintProperty() = default;
-
-    UnevaluatedPaintProperty(Value value_,
-                             UnevaluatedPaintProperty<Value> prior_,
-                             TransitionOptions transition,
-                             TimePoint now)
-        : begin(now + transition.delay.value_or(Duration::zero())),
-          end(begin + transition.duration.value_or(Duration::zero())),
-          value(std::move(value_)) {
-        if (transition.isDefined()) {
-            prior = { std::move(prior_) };
-        }
-    }
-
-    template <class Evaluator>
-    auto evaluate(const Evaluator& evaluator, TimePoint now) {
-        auto finalValue = value.evaluate(evaluator);
-        if (!prior) {
-            // No prior value.
-            return finalValue;
-        } else if (now >= end) {
-            // Transition from prior value is now complete.
-            prior = {};
-            return finalValue;
-        } else if (value.isDataDriven()) {
-            // Transitions to data-driven properties are not supported.
-            // We snap immediately to the data-driven value so that, when we perform layout,
-            // we see the data-driven function and can use it to populate vertex buffers.
-            prior = {};
-            return finalValue;
-        } else if (now < begin) {
-            // Transition hasn't started yet.
-            return prior->get().evaluate(evaluator, now);
-        } else {
-            // Interpolate between recursively-calculated prior value and final.
-            float t = std::chrono::duration<float>(now - begin) / (end - begin);
-            return util::interpolate(prior->get().evaluate(evaluator, now), finalValue, util::DEFAULT_TRANSITION_EASE.solve(t, 0.001));
-        }
-    }
-
-    bool hasTransition() const {
-        return bool(prior);
-    }
-
-    bool isUndefined() const {
-        return value.isUndefined();
-    }
-
-    const Value& getValue() const {
-        return value;
-    }
-
-private:
-    optional<mapbox::util::recursive_wrapper<UnevaluatedPaintProperty<Value>>> prior;
-    TimePoint begin;
-    TimePoint end;
-    Value value;
-};
-
-template <class Value>
 class CascadingPaintProperty {
 public:
     bool isUndefined() const {
@@ -112,8 +51,8 @@ public:
         transitions[klass ? ClassDictionary::Get().lookup(*klass) : ClassID::Default] = transition;
     }
 
-    template <class UnevaluatedPaintProperty>
-    UnevaluatedPaintProperty cascade(const CascadeParameters& params, UnevaluatedPaintProperty prior) const {
+    template <class TransitioningProperty>
+    TransitioningProperty cascade(const CascadeParameters& params, TransitioningProperty prior) const {
         TransitionOptions transition;
         Value value;
 
@@ -131,7 +70,7 @@ public:
             }
         }
 
-        return UnevaluatedPaintProperty(std::move(value),
+        return TransitioningProperty(std::move(value),
                                         std::move(prior),
                                         transition.reverseMerge(params.transition),
                                         params.now);
@@ -147,7 +86,7 @@ class PaintProperty {
 public:
     using ValueType = PropertyValue<T>;
     using CascadingType = CascadingPaintProperty<ValueType>;
-    using UnevaluatedType = UnevaluatedPaintProperty<ValueType>;
+    using UnevaluatedType = TransitioningProperty<ValueType>;
     using EvaluatorType = PropertyEvaluator<T>;
     using EvaluatedType = T;
     static constexpr bool IsDataDriven = false;
@@ -158,7 +97,7 @@ class DataDrivenPaintProperty {
 public:
     using ValueType = DataDrivenPropertyValue<T>;
     using CascadingType = CascadingPaintProperty<ValueType>;
-    using UnevaluatedType = UnevaluatedPaintProperty<ValueType>;
+    using UnevaluatedType = TransitioningProperty<ValueType>;
     using EvaluatorType = DataDrivenPropertyEvaluator<T>;
     using EvaluatedType = PossiblyEvaluatedPropertyValue<T>;
     static constexpr bool IsDataDriven = true;
@@ -172,7 +111,7 @@ class CrossFadedPaintProperty {
 public:
     using ValueType = PropertyValue<T>;
     using CascadingType = CascadingPaintProperty<ValueType>;
-    using UnevaluatedType = UnevaluatedPaintProperty<ValueType>;
+    using UnevaluatedType = TransitioningProperty<ValueType>;
     using EvaluatorType = CrossFadedPropertyEvaluator<T>;
     using EvaluatedType = Faded<T>;
     static constexpr bool IsDataDriven = false;