[core] Move render-related sources out of style directory/namespace

Moves the following to the renderer directory and out of the style namespace:

* CascadeParameters
* PropertyEvaluationParameters
* UpdateParameters
* PropertyEvaluator
* DataDrivenPropertyEvaluator
* CrossFadedPropertyEvaluator
* PaintPropertyBinder
* PaintProperyStatistics
* PossiblyEvaluatedPropertyValue
* TransitioningLight
* EvaluatedLight

36 files changed, 866 insertions, 51 deletions

diff --git a/src/mbgl/renderer/cascade_parameters.hpp b/src/mbgl/renderer/cascade_parameters.hpp
new file mode 100644
index 0000000000..4096cc5a6b
--- /dev/null
+++ b/src/mbgl/renderer/cascade_parameters.hpp
@@ -0,0 +1,18 @@
+#pragma once
+
+#include <mbgl/util/chrono.hpp>
+#include <mbgl/style/class_dictionary.hpp>
+#include <mbgl/style/transition_options.hpp>
+
+#include <vector>
+
+namespace mbgl {
+
+class CascadeParameters {
+public:
+    std::vector<style::ClassID> classes;
+    TimePoint now;
+    style::TransitionOptions transition;
+};
+
+} // namespace mbgl
diff --git a/src/mbgl/renderer/cross_faded_property_evaluator.cpp b/src/mbgl/renderer/cross_faded_property_evaluator.cpp
new file mode 100644
index 0000000000..ee3c86614f
--- /dev/null
+++ b/src/mbgl/renderer/cross_faded_property_evaluator.cpp
@@ -0,0 +1,40 @@
+#include <mbgl/renderer/cross_faded_property_evaluator.hpp>
+#include <mbgl/util/chrono.hpp>
+
+#include <cmath>
+
+namespace mbgl {
+
+template <typename T>
+Faded<T> CrossFadedPropertyEvaluator<T>::operator()(const style::Undefined&) const {
+    return calculate(defaultValue, defaultValue, defaultValue);
+}
+
+template <typename T>
+Faded<T> CrossFadedPropertyEvaluator<T>::operator()(const T& constant) const {
+    return calculate(constant, constant, constant);
+}
+
+template <typename T>
+Faded<T> CrossFadedPropertyEvaluator<T>::operator()(const style::CameraFunction<T>& function) const {
+    return calculate(function.evaluate(parameters.z - 1.0f),
+                     function.evaluate(parameters.z),
+                     function.evaluate(parameters.z + 1.0f));
+}
+
+template <typename T>
+Faded<T> CrossFadedPropertyEvaluator<T>::calculate(const T& min, const T& mid, const T& max) const {
+    const float z = parameters.z;
+    const float fraction = z - std::floor(z);
+    const std::chrono::duration<float> d = parameters.defaultFadeDuration;
+    const float t = std::min((parameters.now - parameters.zoomHistory.lastIntegerZoomTime) / d, 1.0f);
+
+    return z > parameters.zoomHistory.lastIntegerZoom
+        ? Faded<T> { min, mid, 2.0f, 1.0f, fraction + (1.0f - fraction) * t }
+        : Faded<T> { max, mid, 0.5f, 1.0f, 1 - (1 - t) * fraction };
+}
+
+template class CrossFadedPropertyEvaluator<std::string>;
+template class CrossFadedPropertyEvaluator<std::vector<float>>;
+
+} // namespace mbgl
diff --git a/src/mbgl/renderer/cross_faded_property_evaluator.hpp b/src/mbgl/renderer/cross_faded_property_evaluator.hpp
new file mode 100644
index 0000000000..40ecba5d93
--- /dev/null
+++ b/src/mbgl/renderer/cross_faded_property_evaluator.hpp
@@ -0,0 +1,45 @@
+#pragma once
+
+#include <mbgl/style/property_value.hpp>
+#include <mbgl/renderer/property_evaluation_parameters.hpp>
+#include <mbgl/util/interpolate.hpp>
+
+namespace mbgl {
+
+template <typename T>
+class Faded {
+public:
+    T from;
+    T to;
+    float fromScale;
+    float toScale;
+    float t;
+};
+
+template <typename T>
+class CrossFadedPropertyEvaluator {
+public:
+    using ResultType = Faded<T>;
+
+    CrossFadedPropertyEvaluator(const PropertyEvaluationParameters& parameters_, T defaultValue_)
+        : parameters(parameters_),
+          defaultValue(std::move(defaultValue_)) {}
+
+    Faded<T> operator()(const style::Undefined&) const;
+    Faded<T> operator()(const T& constant) const;
+    Faded<T> operator()(const style::CameraFunction<T>&) const;
+
+private:
+    Faded<T> calculate(const T& min, const T& mid, const T& max) const;
+
+    const PropertyEvaluationParameters& parameters;
+    T defaultValue;
+};
+
+namespace util {
+template <typename T>
+struct Interpolator<Faded<T>>
+    : Uninterpolated {};
+} // namespace util
+
+} // namespace mbgl
diff --git a/src/mbgl/renderer/data_driven_property_evaluator.hpp b/src/mbgl/renderer/data_driven_property_evaluator.hpp
new file mode 100644
index 0000000000..6406b3478b
--- /dev/null
+++ b/src/mbgl/renderer/data_driven_property_evaluator.hpp
@@ -0,0 +1,40 @@
+#pragma once
+
+#include <mbgl/style/property_value.hpp>
+#include <mbgl/renderer/property_evaluation_parameters.hpp>
+#include <mbgl/renderer/possibly_evaluated_property_value.hpp>
+
+namespace mbgl {
+
+template <typename T>
+class DataDrivenPropertyEvaluator {
+public:
+    using ResultType = PossiblyEvaluatedPropertyValue<T>;
+
+    DataDrivenPropertyEvaluator(const PropertyEvaluationParameters& parameters_, T defaultValue_)
+        : parameters(parameters_),
+          defaultValue(std::move(defaultValue_)) {}
+
+    ResultType operator()(const style::Undefined&) const {
+        return ResultType(defaultValue);
+    }
+
+    ResultType operator()(const T& constant) const {
+        return ResultType(constant);
+    }
+
+    ResultType operator()(const style::CameraFunction<T>& function) const {
+        return ResultType(function.evaluate(parameters.z));
+    }
+
+    template <class Function>
+    ResultType operator()(const Function& function) const {
+        return ResultType(function);
+    }
+
+private:
+    const PropertyEvaluationParameters& parameters;
+    T defaultValue;
+};
+
+} // namespace mbgl
diff --git a/src/mbgl/renderer/paint_property_binder.hpp b/src/mbgl/renderer/paint_property_binder.hpp
new file mode 100644
index 0000000000..3e53bcc884
--- /dev/null
+++ b/src/mbgl/renderer/paint_property_binder.hpp
@@ -0,0 +1,330 @@
+#pragma once
+
+#include <mbgl/programs/attributes.hpp>
+#include <mbgl/gl/attribute.hpp>
+#include <mbgl/gl/uniform.hpp>
+#include <mbgl/util/type_list.hpp>
+#include <mbgl/renderer/paint_property_statistics.hpp>
+
+namespace mbgl {
+
+/*
+   ZoomInterpolatedAttribute<Attr> is a 'compound' attribute, representing two values of the
+   the base attribute Attr.  These two values are provided to the shader to allow interpolation
+   between zoom levels, without the need to repopulate vertex buffers each frame as the map is
+   being zoomed.
+*/
+template <class A>
+using ZoomInterpolatedAttributeType = gl::Attribute<typename A::ValueType, A::Dimensions * 2>;
+
+inline std::array<float, 1> attributeValue(float v) {
+    return {{ v }};
+}
+
+/*
+    Encode a four-component color value into a pair of floats.  Since csscolorparser
+    uses 8-bit precision for each color component, for each float we use the upper 8
+    bits for one component (e.g. (color.r * 255) * 256), and the lower 8 for another.
+    
+    Also note that colors come in as floats 0..1, so we scale by 255.
+*/
+inline std::array<float, 2> attributeValue(const Color& color) {
+    return {{
+        static_cast<float>(mbgl::attributes::packUint8Pair(255 * color.r, 255 * color.g)),
+        static_cast<float>(mbgl::attributes::packUint8Pair(255 * color.b, 255 * color.a))
+    }};
+}
+
+template <size_t N>
+std::array<float, N*2> zoomInterpolatedAttributeValue(const std::array<float, N>& min, const std::array<float, N>& max) {
+    std::array<float, N*2> result;
+    for (size_t i = 0; i < N; i++) {
+        result[i]   = min[i];
+        result[i+N] = max[i];
+    }
+    return result;
+}
+
+/*
+   PaintPropertyBinder is an abstract class serving as the interface definition for
+   the strategy used for constructing, uploading, and binding paint property data as
+   GLSL attributes.
+
+   It has three concrete subclasses, one for each of the three strategies we use:
+
+   * For _constant_ properties -- those whose value is a constant, or the constant
+     result of evaluating a camera function at a particular camera position -- we
+     don't need a vertex buffer, and can instead use a constant attribute binding
+     via the `glVertexAttrib*` family of functions.
+   * For source functions, we use a vertex buffer with a single attribute value,
+     the evaluated result of the source function for the given feature.
+   * For composite functions, we use a vertex buffer with two attributes: min and
+     max values covering the range of zooms at which we expect the tile to be
+     displayed. These values are calculated by evaluating the composite function for
+     the given feature at strategically chosen zoom levels. In addition to this
+     attribute data, we also use a uniform value which the shader uses to interpolate
+     between the min and max value at the final displayed zoom level. The use of a
+     uniform allows us to cheaply update the value on every frame.
+
+   Note that the shader source is the same regardless of the strategy used to bind
+   the attribute -- in all cases the attribute is declared as a vec2, in order to
+   support composite min and max values (color attributes use a vec4 with special
+   packing). When the constant or source function strategies are used, the
+   interpolation uniform value is set to zero, and the second attribute element is
+   unused. This differs from the GL JS implementation, which dynamically generates
+   shader source based on the strategy used. We found that in WebGL, using
+   `glVertexAttrib*` was unnacceptably slow. Additionally, in GL Native we have
+   implemented binary shader caching, which works better if the shaders are constant.
+*/
+template <class T, class A>
+class PaintPropertyBinder {
+public:
+    using Attribute = ZoomInterpolatedAttributeType<A>;
+    using AttributeBinding = typename Attribute::Binding;
+
+    virtual ~PaintPropertyBinder() = default;
+
+    virtual void populateVertexVector(const GeometryTileFeature& feature, std::size_t length) = 0;
+    virtual void upload(gl::Context& context) = 0;
+    virtual AttributeBinding attributeBinding(const PossiblyEvaluatedPropertyValue<T>& currentValue) const = 0;
+    virtual float interpolationFactor(float currentZoom) const = 0;
+
+    static std::unique_ptr<PaintPropertyBinder> create(const PossiblyEvaluatedPropertyValue<T>& value, float zoom, T defaultValue);
+
+    PaintPropertyStatistics<T> statistics;
+};
+
+template <class T, class A>
+class ConstantPaintPropertyBinder : public PaintPropertyBinder<T, A> {
+public:
+    using Attribute = ZoomInterpolatedAttributeType<A>;
+    using AttributeBinding = typename Attribute::Binding;
+
+    ConstantPaintPropertyBinder(T constant_)
+        : constant(std::move(constant_)) {
+    }
+
+    void populateVertexVector(const GeometryTileFeature&, std::size_t) override {}
+    void upload(gl::Context&) override {}
+
+    AttributeBinding attributeBinding(const PossiblyEvaluatedPropertyValue<T>& currentValue) const override {
+        auto value = attributeValue(currentValue.constantOr(constant));
+        return typename Attribute::ConstantBinding {
+            zoomInterpolatedAttributeValue(value, value)
+        };
+    }
+
+    float interpolationFactor(float) const override {
+        return 0.0f;
+    }
+
+private:
+    T constant;
+};
+
+template <class T, class A>
+class SourceFunctionPaintPropertyBinder : public PaintPropertyBinder<T, A> {
+public:
+    using BaseAttribute = A;
+    using BaseAttributeValue = typename BaseAttribute::Value;
+    using BaseVertex = gl::detail::Vertex<BaseAttribute>;
+
+    using Attribute = ZoomInterpolatedAttributeType<A>;
+    using AttributeBinding = typename Attribute::Binding;
+
+    SourceFunctionPaintPropertyBinder(style::SourceFunction<T> function_, T defaultValue_)
+        : function(std::move(function_)),
+          defaultValue(std::move(defaultValue_)) {
+    }
+
+    void populateVertexVector(const GeometryTileFeature& feature, std::size_t length) override {
+        auto evaluated = function.evaluate(feature, defaultValue);
+        this->statistics.add(evaluated);
+        auto value = attributeValue(evaluated);
+        for (std::size_t i = vertexVector.vertexSize(); i < length; ++i) {
+            vertexVector.emplace_back(BaseVertex { value });
+        }
+    }
+
+    void upload(gl::Context& context) override {
+        vertexBuffer = context.createVertexBuffer(std::move(vertexVector));
+    }
+
+    AttributeBinding attributeBinding(const PossiblyEvaluatedPropertyValue<T>& currentValue) const override {
+        if (currentValue.isConstant()) {
+            BaseAttributeValue value = attributeValue(*currentValue.constant());
+            return typename Attribute::ConstantBinding {
+                zoomInterpolatedAttributeValue(value, value)
+            };
+        } else {
+            return Attribute::variableBinding(*vertexBuffer, 0, BaseAttribute::Dimensions);
+        }
+    }
+
+    float interpolationFactor(float) const override {
+        return 0.0f;
+    }
+
+private:
+    style::SourceFunction<T> function;
+    T defaultValue;
+    gl::VertexVector<BaseVertex> vertexVector;
+    optional<gl::VertexBuffer<BaseVertex>> vertexBuffer;
+};
+
+template <class T, class A>
+class CompositeFunctionPaintPropertyBinder : public PaintPropertyBinder<T, A> {
+public:
+    using BaseAttribute = A;
+    using BaseAttributeValue = typename BaseAttribute::Value;
+
+    using Attribute = ZoomInterpolatedAttributeType<A>;
+    using AttributeValue = typename Attribute::Value;
+    using AttributeBinding = typename Attribute::Binding;
+    using Vertex = gl::detail::Vertex<Attribute>;
+
+    CompositeFunctionPaintPropertyBinder(style::CompositeFunction<T> function_, float zoom, T defaultValue_)
+        : function(std::move(function_)),
+          defaultValue(std::move(defaultValue_)),
+          coveringRanges(function.coveringRanges(zoom)) {
+    }
+
+    void populateVertexVector(const GeometryTileFeature& feature, std::size_t length) override {
+        Range<T> range = function.evaluate(std::get<1>(coveringRanges), feature, defaultValue);
+        this->statistics.add(range.min);
+        this->statistics.add(range.max);
+        AttributeValue value = zoomInterpolatedAttributeValue(
+            attributeValue(range.min),
+            attributeValue(range.max));
+        for (std::size_t i = vertexVector.vertexSize(); i < length; ++i) {
+            vertexVector.emplace_back(Vertex { value });
+        }
+    }
+
+    void upload(gl::Context& context) override {
+        vertexBuffer = context.createVertexBuffer(std::move(vertexVector));
+    }
+
+    AttributeBinding attributeBinding(const PossiblyEvaluatedPropertyValue<T>& currentValue) const override {
+        if (currentValue.isConstant()) {
+            BaseAttributeValue value = attributeValue(*currentValue.constant());
+            return typename Attribute::ConstantBinding {
+                zoomInterpolatedAttributeValue(value, value)
+            };
+        } else {
+            return Attribute::variableBinding(*vertexBuffer, 0);
+        }
+    }
+
+    float interpolationFactor(float currentZoom) const override {
+        return util::interpolationFactor(1.0f, std::get<0>(coveringRanges), currentZoom);
+    }
+
+private:
+    using InnerStops = typename style::CompositeFunction<T>::InnerStops;
+    style::CompositeFunction<T> function;
+    T defaultValue;
+    std::tuple<Range<float>, Range<InnerStops>> coveringRanges;
+    gl::VertexVector<Vertex> vertexVector;
+    optional<gl::VertexBuffer<Vertex>> vertexBuffer;
+};
+
+template <class T, class A>
+std::unique_ptr<PaintPropertyBinder<T, A>>
+PaintPropertyBinder<T, A>::create(const PossiblyEvaluatedPropertyValue<T>& value, float zoom, T defaultValue) {
+    return value.match(
+        [&] (const T& constant) -> std::unique_ptr<PaintPropertyBinder<T, A>> {
+            return std::make_unique<ConstantPaintPropertyBinder<T, A>>(constant);
+        },
+        [&] (const style::SourceFunction<T>& function) {
+            return std::make_unique<SourceFunctionPaintPropertyBinder<T, A>>(function, defaultValue);
+        },
+        [&] (const style::CompositeFunction<T>& function) {
+            return std::make_unique<CompositeFunctionPaintPropertyBinder<T, A>>(function, zoom, defaultValue);
+        }
+    );
+}
+
+template <class Attr>
+struct ZoomInterpolatedAttribute {
+    static auto name() { return Attr::name(); }
+    using Type = ZoomInterpolatedAttributeType<typename Attr::Type>;
+};
+
+template <class Attr>
+struct InterpolationUniform : gl::UniformScalar<InterpolationUniform<Attr>, float> {
+    static auto name() {
+        static const std::string name = Attr::name() + std::string("_t");
+        return name.c_str();
+    }
+};
+
+template <class Ps>
+class PaintPropertyBinders;
+
+template <class... Ps>
+class PaintPropertyBinders<TypeList<Ps...>> {
+public:
+    template <class P>
+    using Binder = PaintPropertyBinder<typename P::Type, typename P::Attribute::Type>;
+
+    using Binders = IndexedTuple<
+        TypeList<Ps...>,
+        TypeList<std::unique_ptr<Binder<Ps>>...>>;
+
+    template <class EvaluatedProperties>
+    PaintPropertyBinders(const EvaluatedProperties& properties, float z)
+        : binders(Binder<Ps>::create(properties.template get<Ps>(), z, Ps::defaultValue())...) {
+        (void)z; // Workaround for https://gcc.gnu.org/bugzilla/show_bug.cgi?id=56958
+    }
+
+    PaintPropertyBinders(PaintPropertyBinders&&) = default;
+    PaintPropertyBinders(const PaintPropertyBinders&) = delete;
+
+    void populateVertexVectors(const GeometryTileFeature& feature, std::size_t length) {
+        util::ignore({
+            (binders.template get<Ps>()->populateVertexVector(feature, length), 0)...
+        });
+    }
+
+    void upload(gl::Context& context) {
+        util::ignore({
+            (binders.template get<Ps>()->upload(context), 0)...
+        });
+    }
+
+    template <class P>
+    using Attribute = ZoomInterpolatedAttribute<typename P::Attribute>;
+
+    using Attributes = gl::Attributes<Attribute<Ps>...>;
+    using AttributeBindings = typename Attributes::Bindings;
+
+    template <class EvaluatedProperties>
+    AttributeBindings attributeBindings(const EvaluatedProperties& currentProperties) const {
+        return AttributeBindings {
+            binders.template get<Ps>()->attributeBinding(currentProperties.template get<Ps>())...
+        };
+    }
+
+    using Uniforms = gl::Uniforms<InterpolationUniform<typename Ps::Attribute>...>;
+    using UniformValues = typename Uniforms::Values;
+
+    UniformValues uniformValues(float currentZoom) const {
+        (void)currentZoom; // Workaround for https://gcc.gnu.org/bugzilla/show_bug.cgi?id=56958
+        return UniformValues {
+            typename InterpolationUniform<typename Ps::Attribute>::Value {
+                binders.template get<Ps>()->interpolationFactor(currentZoom)
+            }...
+        };
+    }
+
+    template <class P>
+    const auto& statistics() const {
+        return binders.template get<P>()->statistics;
+    }
+
+private:
+    Binders binders;
+};
+
+} // namespace mbgl
diff --git a/src/mbgl/renderer/paint_property_statistics.hpp b/src/mbgl/renderer/paint_property_statistics.hpp
new file mode 100644
index 0000000000..59a8545911
--- /dev/null
+++ b/src/mbgl/renderer/paint_property_statistics.hpp
@@ -0,0 +1,29 @@
+#pragma once
+
+#include <mbgl/util/optional.hpp>
+
+namespace mbgl {
+
+template <class T>
+class PaintPropertyStatistics {
+public:
+    optional<T> max() const { return {}; }
+    void add(const T&) {}
+};
+
+template <>
+class PaintPropertyStatistics<float> {
+public:
+    optional<float> max() const {
+        return _max;
+    }
+
+    void add(float value) {
+        _max = _max ? std::max(*_max, value) : value;
+    }
+
+private:
+    optional<float> _max;
+};
+
+} // namespace mbgl
diff --git a/src/mbgl/renderer/painter.hpp b/src/mbgl/renderer/painter.hpp
index c7c8173d0d..ff72749718 100644
--- a/src/mbgl/renderer/painter.hpp
+++ b/src/mbgl/renderer/painter.hpp
@@ -158,7 +158,7 @@ private:
     GlyphAtlas* glyphAtlas = nullptr;
     LineAtlas* lineAtlas = nullptr;
 
-    style::EvaluatedLight evaluatedLight;
+    EvaluatedLight evaluatedLight;
 
     FrameHistory frameHistory;
 
diff --git a/src/mbgl/renderer/possibly_evaluated_property_value.hpp b/src/mbgl/renderer/possibly_evaluated_property_value.hpp
new file mode 100644
index 0000000000..a0bcec2bf1
--- /dev/null
+++ b/src/mbgl/renderer/possibly_evaluated_property_value.hpp
@@ -0,0 +1,74 @@
+#pragma once
+
+#include <mbgl/style/function/source_function.hpp>
+#include <mbgl/style/function/composite_function.hpp>
+#include <mbgl/util/interpolate.hpp>
+#include <mbgl/util/variant.hpp>
+
+namespace mbgl {
+
+template <class T>
+class PossiblyEvaluatedPropertyValue {
+private:
+    using Value = variant<
+        T,
+        style::SourceFunction<T>,
+        style::CompositeFunction<T>>;
+
+    Value value;
+
+public:
+    PossiblyEvaluatedPropertyValue() = default;
+    PossiblyEvaluatedPropertyValue(Value v) : value(std::move(v)) {}
+
+    bool isConstant() const {
+        return value.template is<T>();
+    }
+
+    optional<T> constant() const {
+        return value.match(
+            [&] (const T& t) { return optional<T>(t); },
+            [&] (const auto&) { return optional<T>(); });
+    }
+
+    T constantOr(const T& t) const {
+        return constant().value_or(t);
+    }
+
+    template <class... Ts>
+    auto match(Ts&&... ts) const {
+        return value.match(std::forward<Ts>(ts)...);
+    }
+
+    template <class Feature>
+    T evaluate(const Feature& feature, float zoom, T defaultValue) const {
+        return this->match(
+                [&] (const T& constant) { return constant; },
+                [&] (const style::SourceFunction<T>& function) {
+                    return function.evaluate(feature, defaultValue);
+                },
+                [&] (const style::CompositeFunction<T>& function) {
+                    return function.evaluate(zoom, feature, defaultValue);
+                }
+        );
+    }
+};
+
+namespace util {
+
+template <typename T>
+struct Interpolator<PossiblyEvaluatedPropertyValue<T>> {
+    PossiblyEvaluatedPropertyValue<T> operator()(const PossiblyEvaluatedPropertyValue<T>& a,
+                                                 const PossiblyEvaluatedPropertyValue<T>& b,
+                                                 const double t) const {
+        if (a.isConstant() && b.isConstant()) {
+            return { interpolate(*a.constant(), *b.constant(), t) };
+        } else {
+            return { a };
+        }
+    }
+};
+
+} // namespace util
+
+} // namespace mbgl
diff --git a/src/mbgl/renderer/property_evaluation_parameters.hpp b/src/mbgl/renderer/property_evaluation_parameters.hpp
new file mode 100644
index 0000000000..b18fe57aca
--- /dev/null
+++ b/src/mbgl/renderer/property_evaluation_parameters.hpp
@@ -0,0 +1,28 @@
+#pragma once
+
+#include <mbgl/map/zoom_history.hpp>
+#include <mbgl/util/chrono.hpp>
+
+namespace mbgl {
+
+class PropertyEvaluationParameters {
+public:
+    explicit PropertyEvaluationParameters(float z_)
+        : z(z_) {}
+
+    PropertyEvaluationParameters(float z_,
+                          TimePoint now_,
+                          ZoomHistory zoomHistory_,
+                          Duration defaultFadeDuration_)
+        : z(z_),
+          now(std::move(now_)),
+          zoomHistory(std::move(zoomHistory_)),
+          defaultFadeDuration(std::move(defaultFadeDuration_)) {}
+
+    float z;
+    TimePoint now;
+    ZoomHistory zoomHistory;
+    Duration defaultFadeDuration;
+};
+
+} // namespace mbgl
diff --git a/src/mbgl/renderer/property_evaluator.hpp b/src/mbgl/renderer/property_evaluator.hpp
new file mode 100644
index 0000000000..3ac0573920
--- /dev/null
+++ b/src/mbgl/renderer/property_evaluator.hpp
@@ -0,0 +1,26 @@
+#pragma once
+
+#include <mbgl/style/property_value.hpp>
+#include <mbgl/renderer/property_evaluation_parameters.hpp>
+
+namespace mbgl {
+
+template <typename T>
+class PropertyEvaluator {
+public:
+    using ResultType = T;
+
+    PropertyEvaluator(const PropertyEvaluationParameters& parameters_, T defaultValue_)
+        : parameters(parameters_),
+          defaultValue(std::move(defaultValue_)) {}
+
+    T operator()(const style::Undefined&) const { return defaultValue; }
+    T operator()(const T& constant) const { return constant; }
+    T operator()(const style::CameraFunction<T>& fn) const { return fn.evaluate(parameters.z); }
+
+private:
+    const PropertyEvaluationParameters& parameters;
+    T defaultValue;
+};
+
+} // namespace mbgl
diff --git a/src/mbgl/renderer/render_background_layer.cpp b/src/mbgl/renderer/render_background_layer.cpp
index 5b98210975..a6b4a5e36e 100644
--- a/src/mbgl/renderer/render_background_layer.cpp
+++ b/src/mbgl/renderer/render_background_layer.cpp
@@ -19,11 +19,11 @@ std::unique_ptr<Bucket> RenderBackgroundLayer::createBucket(const BucketParamete
     return nullptr;
 }
 
-void RenderBackgroundLayer::cascade(const style::CascadeParameters &parameters) {
+void RenderBackgroundLayer::cascade(const CascadeParameters &parameters) {
     unevaluated = impl->cascading.cascade(parameters, std::move(unevaluated));
 }
 
-bool RenderBackgroundLayer::evaluate(const style::PropertyEvaluationParameters &parameters) {
+bool RenderBackgroundLayer::evaluate(const PropertyEvaluationParameters &parameters) {
     evaluated = unevaluated.evaluate(parameters);
 
     passes = evaluated.get<style::BackgroundOpacity>() > 0 ? RenderPass::Translucent
diff --git a/src/mbgl/renderer/render_background_layer.hpp b/src/mbgl/renderer/render_background_layer.hpp
index bd74f7b390..137980389c 100644
--- a/src/mbgl/renderer/render_background_layer.hpp
+++ b/src/mbgl/renderer/render_background_layer.hpp
@@ -14,8 +14,8 @@ public:
 
     std::unique_ptr<RenderLayer> clone() const override;
 
-    void cascade(const style::CascadeParameters&) override;
-    bool evaluate(const style::PropertyEvaluationParameters&) override;
+    void cascade(const CascadeParameters&) override;
+    bool evaluate(const PropertyEvaluationParameters&) override;
 
     std::unique_ptr<Bucket> createBucket(const BucketParameters&, const std::vector<const RenderLayer*>&) const override;
 
diff --git a/src/mbgl/renderer/render_circle_layer.cpp b/src/mbgl/renderer/render_circle_layer.cpp
index aa127e9859..56832d53cb 100644
--- a/src/mbgl/renderer/render_circle_layer.cpp
+++ b/src/mbgl/renderer/render_circle_layer.cpp
@@ -20,11 +20,11 @@ std::unique_ptr<Bucket> RenderCircleLayer::createBucket(const BucketParameters&
     return std::make_unique<CircleBucket>(parameters, layers);
 }
 
-void RenderCircleLayer::cascade(const style::CascadeParameters& parameters) {
+void RenderCircleLayer::cascade(const CascadeParameters& parameters) {
     unevaluated = impl->cascading.cascade(parameters, std::move(unevaluated));
 }
 
-bool RenderCircleLayer::evaluate(const style::PropertyEvaluationParameters& parameters) {
+bool RenderCircleLayer::evaluate(const PropertyEvaluationParameters& parameters) {
     evaluated = unevaluated.evaluate(parameters);
 
     passes = ((evaluated.get<style::CircleRadius>().constantOr(1) > 0 ||
diff --git a/src/mbgl/renderer/render_circle_layer.hpp b/src/mbgl/renderer/render_circle_layer.hpp
index 5117b12246..8a2f73ec83 100644
--- a/src/mbgl/renderer/render_circle_layer.hpp
+++ b/src/mbgl/renderer/render_circle_layer.hpp
@@ -14,8 +14,8 @@ public:
 
     std::unique_ptr<RenderLayer> clone() const override;
 
-    void cascade(const style::CascadeParameters&) override;
-    bool evaluate(const style::PropertyEvaluationParameters&) override;
+    void cascade(const CascadeParameters&) override;
+    bool evaluate(const PropertyEvaluationParameters&) override;
 
     bool queryIntersectsFeature(
             const GeometryCoordinates&,
diff --git a/src/mbgl/renderer/render_custom_layer.cpp b/src/mbgl/renderer/render_custom_layer.cpp
index f9dda47d7a..d500d11f4a 100644
--- a/src/mbgl/renderer/render_custom_layer.cpp
+++ b/src/mbgl/renderer/render_custom_layer.cpp
@@ -13,7 +13,7 @@ std::unique_ptr<RenderLayer> RenderCustomLayer::clone() const {
     return std::make_unique<RenderCustomLayer>(*this);
 }
 
-bool RenderCustomLayer::evaluate(const style::PropertyEvaluationParameters&) {
+bool RenderCustomLayer::evaluate(const PropertyEvaluationParameters&) {
     passes = RenderPass::Translucent;
     return false;
 }
diff --git a/src/mbgl/renderer/render_custom_layer.hpp b/src/mbgl/renderer/render_custom_layer.hpp
index 3c6c06ff7c..cb728fecb3 100644
--- a/src/mbgl/renderer/render_custom_layer.hpp
+++ b/src/mbgl/renderer/render_custom_layer.hpp
@@ -13,8 +13,8 @@ public:
 
     std::unique_ptr<RenderLayer> clone() const override;
 
-    void cascade(const style::CascadeParameters&) final {}
-    bool evaluate(const style::PropertyEvaluationParameters&) final;
+    void cascade(const CascadeParameters&) final {}
+    bool evaluate(const PropertyEvaluationParameters&) final;
 
     std::unique_ptr<Bucket> createBucket(const BucketParameters&, const std::vector<const RenderLayer*>&) const final;
 
diff --git a/src/mbgl/renderer/render_fill_extrusion_layer.cpp b/src/mbgl/renderer/render_fill_extrusion_layer.cpp
index 8df0d36900..70ee74b56e 100644
--- a/src/mbgl/renderer/render_fill_extrusion_layer.cpp
+++ b/src/mbgl/renderer/render_fill_extrusion_layer.cpp
@@ -20,11 +20,11 @@ std::unique_ptr<Bucket> RenderFillExtrusionLayer::createBucket(const BucketParam
     return std::make_unique<FillExtrusionBucket>(parameters, layers);
 }
 
-void RenderFillExtrusionLayer::cascade(const style::CascadeParameters& parameters) {
+void RenderFillExtrusionLayer::cascade(const CascadeParameters& parameters) {
     unevaluated = impl->cascading.cascade(parameters, std::move(unevaluated));
 }
 
-bool RenderFillExtrusionLayer::evaluate(const style::PropertyEvaluationParameters& parameters) {
+bool RenderFillExtrusionLayer::evaluate(const PropertyEvaluationParameters& parameters) {
     evaluated = unevaluated.evaluate(parameters);
 
     passes = (evaluated.get<style::FillExtrusionOpacity>() > 0) ? RenderPass::Translucent
diff --git a/src/mbgl/renderer/render_fill_extrusion_layer.hpp b/src/mbgl/renderer/render_fill_extrusion_layer.hpp
index 87b6ad6071..b4fd1411f5 100644
--- a/src/mbgl/renderer/render_fill_extrusion_layer.hpp
+++ b/src/mbgl/renderer/render_fill_extrusion_layer.hpp
@@ -14,8 +14,8 @@ public:
 
     std::unique_ptr<RenderLayer> clone() const override;
 
-    void cascade(const style::CascadeParameters&) override;
-    bool evaluate(const style::PropertyEvaluationParameters&) override;
+    void cascade(const CascadeParameters&) override;
+    bool evaluate(const PropertyEvaluationParameters&) override;
 
     bool queryIntersectsFeature(
         const GeometryCoordinates&,
diff --git a/src/mbgl/renderer/render_fill_layer.cpp b/src/mbgl/renderer/render_fill_layer.cpp
index 126189fc50..53c1ff3032 100644
--- a/src/mbgl/renderer/render_fill_layer.cpp
+++ b/src/mbgl/renderer/render_fill_layer.cpp
@@ -20,11 +20,11 @@ std::unique_ptr<Bucket> RenderFillLayer::createBucket(const BucketParameters& pa
     return std::make_unique<FillBucket>(parameters, layers);
 }
 
-void RenderFillLayer::cascade(const style::CascadeParameters& parameters) {
+void RenderFillLayer::cascade(const CascadeParameters& parameters) {
     unevaluated = impl->cascading.cascade(parameters, std::move(unevaluated));
 }
 
-bool RenderFillLayer::evaluate(const style::PropertyEvaluationParameters& parameters) {
+bool RenderFillLayer::evaluate(const PropertyEvaluationParameters& parameters) {
     evaluated = unevaluated.evaluate(parameters);
 
     if (unevaluated.get<style::FillOutlineColor>().isUndefined()) {
diff --git a/src/mbgl/renderer/render_fill_layer.hpp b/src/mbgl/renderer/render_fill_layer.hpp
index 25b969d4c3..3a8de3622a 100644
--- a/src/mbgl/renderer/render_fill_layer.hpp
+++ b/src/mbgl/renderer/render_fill_layer.hpp
@@ -14,8 +14,8 @@ public:
 
     std::unique_ptr<RenderLayer> clone() const override;
 
-    void cascade(const style::CascadeParameters&) override;
-    bool evaluate(const style::PropertyEvaluationParameters&) override;
+    void cascade(const CascadeParameters&) override;
+    bool evaluate(const PropertyEvaluationParameters&) override;
 
     bool queryIntersectsFeature(
             const GeometryCoordinates&,
diff --git a/src/mbgl/renderer/render_layer.hpp b/src/mbgl/renderer/render_layer.hpp
index af5345d5e3..003059005e 100644
--- a/src/mbgl/renderer/render_layer.hpp
+++ b/src/mbgl/renderer/render_layer.hpp
@@ -12,11 +12,8 @@ namespace mbgl {
 
 class Bucket;
 class BucketParameters;
-
-namespace style {
 class CascadeParameters;
 class PropertyEvaluationParameters;
-} // namespace style
 
 class RenderLayer {
 
@@ -33,11 +30,11 @@ public:
     virtual std::unique_ptr<RenderLayer> clone() const = 0;
 
     // Partially evaluate paint properties based on a set of classes.
-    virtual void cascade(const style::CascadeParameters&) = 0;
+    virtual void cascade(const CascadeParameters&) = 0;
 
     // Fully evaluate cascaded paint properties based on a zoom level.
     // Returns true if any paint properties have active transitions.
-    virtual bool evaluate(const style::PropertyEvaluationParameters&) = 0;
+    virtual bool evaluate(const PropertyEvaluationParameters&) = 0;
 
     // Check whether this layer is of the given subtype.
     template <class T>
diff --git a/src/mbgl/renderer/render_light.hpp b/src/mbgl/renderer/render_light.hpp
new file mode 100644
index 0000000000..8f59299552
--- /dev/null
+++ b/src/mbgl/renderer/render_light.hpp
@@ -0,0 +1,72 @@
+#pragma once
+
+#include <mbgl/style/light.hpp>
+#include <mbgl/renderer/transitioning_property.hpp>
+#include <mbgl/renderer/cascade_parameters.hpp>
+#include <mbgl/renderer/property_evaluator.hpp>
+#include <mbgl/renderer/property_evaluation_parameters.hpp>
+#include <mbgl/util/ignore.hpp>
+
+namespace mbgl {
+
+template <class TypeList>
+class Transitioning;
+
+template <class... Ps>
+class Transitioning<TypeList<Ps...>> : public IndexedTuple<
+    TypeList<Ps...>,
+    TypeList<TransitioningProperty<typename Ps::ValueType>...>>
+{
+private:
+    using Properties = TypeList<Ps...>;
+    using Raw = IndexedTuple<Properties, Properties>;
+    using Super = IndexedTuple<
+        TypeList<Ps...>,
+        TypeList<TransitioningProperty<typename Ps::ValueType>...>>;
+
+public:
+    Transitioning() = default;
+    Transitioning(const Raw& raw, Transitioning&& prior, const CascadeParameters& params)
+        : Super {
+            TransitioningProperty<typename Ps::ValueType>(
+                raw.template get<Ps>().value,
+                std::move(prior.template get<Ps>()),
+                raw.template get<Ps>().transition.reverseMerge(params.transition),
+                params.now)...
+        } {}
+
+    bool hasTransition() const {
+        bool result = false;
+        util::ignore({ result |= this->template get<Ps>().hasTransition()... });
+        return result;
+    }
+};
+
+template <class TypeList>
+class Evaluated;
+
+template <class... Ps>
+class Evaluated<TypeList<Ps...>> : public IndexedTuple<
+    TypeList<Ps...>,
+    TypeList<typename Ps::Type...>>
+{
+private:
+    using Properties = TypeList<Ps...>;
+    using TransitioningPs = Transitioning<Properties>;
+    using Super = IndexedTuple<
+        TypeList<Ps...>,
+        TypeList<typename Ps::Type...>>;
+
+public:
+    Evaluated() = default;
+    Evaluated(TransitioningPs& transitioning, const PropertyEvaluationParameters& params)
+        : Super {
+            transitioning.template get<Ps>()
+                .evaluate(PropertyEvaluator<typename Ps::Type>(params, Ps::defaultValue()), params.now)...
+        } {}
+};
+
+using TransitioningLight = Transitioning<style::LightProperties>;
+using EvaluatedLight     = Evaluated<style::LightProperties>;
+
+} // namespace mbgl
diff --git a/src/mbgl/renderer/render_line_layer.cpp b/src/mbgl/renderer/render_line_layer.cpp
index 551d40bef5..e5060af79e 100644
--- a/src/mbgl/renderer/render_line_layer.cpp
+++ b/src/mbgl/renderer/render_line_layer.cpp
@@ -20,11 +20,11 @@ std::unique_ptr<Bucket> RenderLineLayer::createBucket(const BucketParameters& pa
     return std::make_unique<LineBucket>(parameters, layers, impl->layout);
 }
 
-void RenderLineLayer::cascade(const style::CascadeParameters& parameters) {
+void RenderLineLayer::cascade(const CascadeParameters& parameters) {
     unevaluated = impl->cascading.cascade(parameters, std::move(unevaluated));
 }
 
-bool RenderLineLayer::evaluate(const style::PropertyEvaluationParameters& parameters) {
+bool RenderLineLayer::evaluate(const PropertyEvaluationParameters& parameters) {
     // for scaling dasharrays
     auto dashArrayParams = parameters;
     dashArrayParams.z = std::floor(dashArrayParams.z);
diff --git a/src/mbgl/renderer/render_line_layer.hpp b/src/mbgl/renderer/render_line_layer.hpp
index 0bde6f9a86..15052deb38 100644
--- a/src/mbgl/renderer/render_line_layer.hpp
+++ b/src/mbgl/renderer/render_line_layer.hpp
@@ -14,8 +14,8 @@ public:
 
     std::unique_ptr<RenderLayer> clone() const override;
 
-    void cascade(const style::CascadeParameters&) override;
-    bool evaluate(const style::PropertyEvaluationParameters&) override;
+    void cascade(const CascadeParameters&) override;
+    bool evaluate(const PropertyEvaluationParameters&) override;
 
     bool queryIntersectsFeature(
             const GeometryCoordinates&,
diff --git a/src/mbgl/renderer/render_raster_layer.cpp b/src/mbgl/renderer/render_raster_layer.cpp
index f877a02398..0cfccc81b3 100644
--- a/src/mbgl/renderer/render_raster_layer.cpp
+++ b/src/mbgl/renderer/render_raster_layer.cpp
@@ -18,11 +18,11 @@ std::unique_ptr<Bucket> RenderRasterLayer::createBucket(const BucketParameters&,
     return nullptr;
 }
 
-void RenderRasterLayer::cascade(const style::CascadeParameters& parameters) {
+void RenderRasterLayer::cascade(const CascadeParameters& parameters) {
     unevaluated = impl->cascading.cascade(parameters, std::move(unevaluated));
 }
 
-bool RenderRasterLayer::evaluate(const style::PropertyEvaluationParameters& parameters) {
+bool RenderRasterLayer::evaluate(const PropertyEvaluationParameters& parameters) {
     evaluated = unevaluated.evaluate(parameters);
 
     passes = evaluated.get<style::RasterOpacity>() > 0 ? RenderPass::Translucent : RenderPass::None;
diff --git a/src/mbgl/renderer/render_raster_layer.hpp b/src/mbgl/renderer/render_raster_layer.hpp
index 1fd0fe7c47..c6e38fa147 100644
--- a/src/mbgl/renderer/render_raster_layer.hpp
+++ b/src/mbgl/renderer/render_raster_layer.hpp
@@ -14,8 +14,8 @@ public:
 
     std::unique_ptr<RenderLayer> clone() const override;
 
-    void cascade(const style::CascadeParameters&) override;
-    bool evaluate(const style::PropertyEvaluationParameters&) override;
+    void cascade(const CascadeParameters&) override;
+    bool evaluate(const PropertyEvaluationParameters&) override;
 
     std::unique_ptr<Bucket> createBucket(const BucketParameters&, const std::vector<const RenderLayer*>&) const override;
 
diff --git a/src/mbgl/renderer/render_source.hpp b/src/mbgl/renderer/render_source.hpp
index 5d93ae49d6..bec1d24d0f 100644
--- a/src/mbgl/renderer/render_source.hpp
+++ b/src/mbgl/renderer/render_source.hpp
@@ -21,15 +21,12 @@ class RenderedQueryOptions;
 class SourceQueryOptions;
 class Tile;
 class RenderSourceObserver;
+class UpdateParameters;
 
 namespace algorithm {
 class ClipIDGenerator;
 } // namespace algorithm
 
-namespace style {
-class UpdateParameters;
-} // namespace style
-
 class RenderSource : protected TileObserver {
 public:
     RenderSource(const style::Source::Impl&);
@@ -39,7 +36,7 @@ public:
 
     // Called when the camera has changed. May load new tiles, unload obsolete tiles, or
     // trigger re-placement of existing complete tiles.
-    virtual void updateTiles(const style::UpdateParameters&) = 0;
+    virtual void updateTiles(const UpdateParameters&) = 0;
 
     // Removes all tiles (by putting them into the cache).
     virtual void removeTiles() = 0;
diff --git a/src/mbgl/renderer/render_symbol_layer.cpp b/src/mbgl/renderer/render_symbol_layer.cpp
index d46dc614f0..0c3601aedf 100644
--- a/src/mbgl/renderer/render_symbol_layer.cpp
+++ b/src/mbgl/renderer/render_symbol_layer.cpp
@@ -2,8 +2,8 @@
 #include <mbgl/layout/symbol_layout.hpp>
 #include <mbgl/renderer/bucket.hpp>
 #include <mbgl/renderer/bucket_parameters.hpp>
+#include <mbgl/renderer/property_evaluation_parameters.hpp>
 #include <mbgl/style/layers/symbol_layer_impl.hpp>
-#include <mbgl/style/property_evaluation_parameters.hpp>
 #include <mbgl/tile/geometry_tile_data.hpp>
 
 namespace mbgl {
@@ -34,11 +34,11 @@ std::unique_ptr<SymbolLayout> RenderSymbolLayer::createLayout(const BucketParame
                                           glyphDependencies);
 }
 
-void RenderSymbolLayer::cascade(const style::CascadeParameters& parameters) {
+void RenderSymbolLayer::cascade(const CascadeParameters& parameters) {
     unevaluated = impl->cascading.cascade(parameters, std::move(unevaluated));
 }
 
-bool RenderSymbolLayer::evaluate(const style::PropertyEvaluationParameters& parameters) {
+bool RenderSymbolLayer::evaluate(const PropertyEvaluationParameters& parameters) {
     evaluated = unevaluated.evaluate(parameters);
 
     auto hasIconOpacity = evaluated.get<style::IconColor>().constantOr(Color::black()).a > 0 ||
diff --git a/src/mbgl/renderer/render_symbol_layer.hpp b/src/mbgl/renderer/render_symbol_layer.hpp
index b19b236e90..b9c2cc3247 100644
--- a/src/mbgl/renderer/render_symbol_layer.hpp
+++ b/src/mbgl/renderer/render_symbol_layer.hpp
@@ -66,8 +66,8 @@ public:
 
     std::unique_ptr<RenderLayer> clone() const override;
 
-    void cascade(const style::CascadeParameters&) override;
-    bool evaluate(const style::PropertyEvaluationParameters&) override;
+    void cascade(const CascadeParameters&) override;
+    bool evaluate(const PropertyEvaluationParameters&) override;
 
     style::IconPaintProperties::Evaluated iconPaintProperties() const;
     style::TextPaintProperties::Evaluated textPaintProperties() const;
diff --git a/src/mbgl/renderer/sources/render_geojson_source.hpp b/src/mbgl/renderer/sources/render_geojson_source.hpp
index 3476b63afd..502df0f1c5 100644
--- a/src/mbgl/renderer/sources/render_geojson_source.hpp
+++ b/src/mbgl/renderer/sources/render_geojson_source.hpp
@@ -18,7 +18,7 @@ public:
 
     // Called when the camera has changed. May load new tiles, unload obsolete tiles, or
     // trigger re-placement of existing complete tiles.
-    void updateTiles(const style::UpdateParameters&) final;
+    void updateTiles(const UpdateParameters&) final;
 
     // Removes all tiles (by putting them into the cache).
     void removeTiles() final;
diff --git a/src/mbgl/renderer/sources/render_raster_source.hpp b/src/mbgl/renderer/sources/render_raster_source.hpp
index 6b95be363f..ebb7b62150 100644
--- a/src/mbgl/renderer/sources/render_raster_source.hpp
+++ b/src/mbgl/renderer/sources/render_raster_source.hpp
@@ -14,7 +14,7 @@ public:
 
     // Called when the camera has changed. May load new tiles, unload obsolete tiles, or
     // trigger re-placement of existing complete tiles.
-    void updateTiles(const style::UpdateParameters&) final;
+    void updateTiles(const UpdateParameters&) final;
 
     // Removes all tiles (by putting them into the cache).
     void removeTiles() final;
diff --git a/src/mbgl/renderer/sources/render_vector_source.hpp b/src/mbgl/renderer/sources/render_vector_source.hpp
index 0f40c14cf5..c435db6f0b 100644
--- a/src/mbgl/renderer/sources/render_vector_source.hpp
+++ b/src/mbgl/renderer/sources/render_vector_source.hpp
@@ -14,7 +14,7 @@ public:
 
     // Called when the camera has changed. May load new tiles, unload obsolete tiles, or
     // trigger re-placement of existing complete tiles.
-    void updateTiles(const style::UpdateParameters&) final;
+    void updateTiles(const UpdateParameters&) final;
 
     // Removes all tiles (by putting them into the cache).
     void removeTiles() final;
diff --git a/src/mbgl/renderer/tile_pyramid.cpp b/src/mbgl/renderer/tile_pyramid.cpp
index 130b9dc5b6..97f9f31937 100644
--- a/src/mbgl/renderer/tile_pyramid.cpp
+++ b/src/mbgl/renderer/tile_pyramid.cpp
@@ -2,7 +2,7 @@
 #include <mbgl/renderer/render_tile.hpp>
 #include <mbgl/renderer/painter.hpp>
 #include <mbgl/renderer/render_source.hpp>
-#include <mbgl/style/update_parameters.hpp>
+#include <mbgl/renderer/update_parameters.hpp>
 #include <mbgl/map/transform.hpp>
 #include <mbgl/map/query.hpp>
 #include <mbgl/text/placement_config.hpp>
diff --git a/src/mbgl/renderer/tile_pyramid.hpp b/src/mbgl/renderer/tile_pyramid.hpp
index a38a21dd88..b8ffbfb2b0 100644
--- a/src/mbgl/renderer/tile_pyramid.hpp
+++ b/src/mbgl/renderer/tile_pyramid.hpp
@@ -22,10 +22,7 @@ class TransformState;
 class RenderTile;
 class RenderedQueryOptions;
 class SourceQueryOptions;
-
-namespace style {
 class UpdateParameters;
-} // namespace style
 
 class TilePyramid {
 public:
@@ -36,7 +33,7 @@ public:
 
     // Called when the camera has changed. May load new tiles, unload obsolete tiles, or
     // trigger re-placement of existing complete tiles.
-    void updateTiles(const style::UpdateParameters&,
+    void updateTiles(const UpdateParameters&,
                      SourceType type,
                      uint16_t tileSize,
                      Range<uint8_t> zoomRange,
diff --git a/src/mbgl/renderer/transitioning_property.hpp b/src/mbgl/renderer/transitioning_property.hpp
new file mode 100644
index 0000000000..c211ccf116
--- /dev/null
+++ b/src/mbgl/renderer/transitioning_property.hpp
@@ -0,0 +1,75 @@
+#pragma once
+
+#include <mbgl/style/property_value.hpp>
+#include <mbgl/style/data_driven_property_value.hpp>
+#include <mbgl/style/transition_options.hpp>
+#include <mbgl/util/interpolate.hpp>
+
+#include <utility>
+
+namespace mbgl {
+
+template <class Value>
+class TransitioningProperty {
+public:
+    TransitioningProperty() = default;
+
+    TransitioningProperty(Value value_,
+                          TransitioningProperty<Value> prior_,
+                          style::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<TransitioningProperty<Value>>> prior;
+    TimePoint begin;
+    TimePoint end;
+    Value value;
+};
+
+} // namespace mbgl
diff --git a/src/mbgl/renderer/update_parameters.hpp b/src/mbgl/renderer/update_parameters.hpp
new file mode 100644
index 0000000000..a00e01b973
--- /dev/null
+++ b/src/mbgl/renderer/update_parameters.hpp
@@ -0,0 +1,47 @@
+#pragma once
+
+#include <mbgl/map/mode.hpp>
+
+namespace mbgl {
+
+class TransformState;
+class Scheduler;
+class FileSource;
+class AnnotationManager;
+
+namespace style {
+class Style;
+} // namespace style
+
+class UpdateParameters {
+public:
+    UpdateParameters(float pixelRatio_,
+                          MapDebugOptions debugOptions_,
+                          const TransformState& transformState_,
+                          Scheduler& workerScheduler_,
+                          FileSource& fileSource_,
+                          const MapMode mode_,
+                          AnnotationManager& annotationManager_,
+                          style::Style& style_)
+        : pixelRatio(pixelRatio_),
+          debugOptions(debugOptions_),
+          transformState(transformState_),
+          workerScheduler(workerScheduler_),
+          fileSource(fileSource_),
+          mode(mode_),
+          annotationManager(annotationManager_),
+          style(style_) {}
+
+    float pixelRatio;
+    MapDebugOptions debugOptions;
+    const TransformState& transformState;
+    Scheduler& workerScheduler;
+    FileSource& fileSource;
+    const MapMode mode;
+    AnnotationManager& annotationManager;
+
+    // TODO: remove
+    style::Style& style;
+};
+
+} // namespace mbgl