Make location indicator bearing a paint property

This change introduces a new property type, Rotation, that uses
a custom interpolator, and that is currently applied to
all style properties named "bearing", with a period attribute.

26 files changed, 231 insertions, 68 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
index fcce303960..c024d7f6cb 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -160,6 +160,7 @@ add_library(
     ${PROJECT_SOURCE_DIR}/include/mbgl/style/conversion/light.hpp
     ${PROJECT_SOURCE_DIR}/include/mbgl/style/conversion/position.hpp
     ${PROJECT_SOURCE_DIR}/include/mbgl/style/conversion/property_value.hpp
+    ${PROJECT_SOURCE_DIR}/include/mbgl/style/conversion/rotation.hpp
     ${PROJECT_SOURCE_DIR}/include/mbgl/style/conversion/source.hpp
     ${PROJECT_SOURCE_DIR}/include/mbgl/style/conversion/tileset.hpp
     ${PROJECT_SOURCE_DIR}/include/mbgl/style/conversion/transition_options.hpp
@@ -217,6 +218,7 @@ add_library(
     ${PROJECT_SOURCE_DIR}/include/mbgl/style/position.hpp
     ${PROJECT_SOURCE_DIR}/include/mbgl/style/property_expression.hpp
     ${PROJECT_SOURCE_DIR}/include/mbgl/style/property_value.hpp
+    ${PROJECT_SOURCE_DIR}/include/mbgl/style/rotation.hpp
     ${PROJECT_SOURCE_DIR}/include/mbgl/style/source.hpp
     ${PROJECT_SOURCE_DIR}/include/mbgl/style/sources/custom_geometry_source.hpp
     ${PROJECT_SOURCE_DIR}/include/mbgl/style/sources/geojson_source.hpp
@@ -548,6 +550,7 @@ add_library(
     ${PROJECT_SOURCE_DIR}/src/mbgl/style/conversion/light.cpp
     ${PROJECT_SOURCE_DIR}/src/mbgl/style/conversion/position.cpp
     ${PROJECT_SOURCE_DIR}/src/mbgl/style/conversion/property_value.cpp
+    ${PROJECT_SOURCE_DIR}/src/mbgl/style/conversion/rotation.cpp
     ${PROJECT_SOURCE_DIR}/src/mbgl/style/conversion/source.cpp
     ${PROJECT_SOURCE_DIR}/src/mbgl/style/conversion/stringify.hpp
     ${PROJECT_SOURCE_DIR}/src/mbgl/style/conversion/tileset.cpp
diff --git a/include/mbgl/style/conversion/rotation.hpp b/include/mbgl/style/conversion/rotation.hpp
new file mode 100644
index 0000000000..86d67240fd
--- /dev/null
+++ b/include/mbgl/style/conversion/rotation.hpp
@@ -0,0 +1,18 @@
+#pragma once
+
+#include <mbgl/style/conversion.hpp>
+#include <mbgl/style/rotation.hpp>
+#include <mbgl/util/optional.hpp>
+
+namespace mbgl {
+namespace style {
+namespace conversion {
+
+template <>
+struct Converter<style::Rotation> {
+    optional<style::Rotation> operator()(const Convertible& value, Error& error) const;
+};
+
+} // namespace conversion
+} // namespace style
+} // namespace mbgl
diff --git a/include/mbgl/style/conversion_impl.hpp b/include/mbgl/style/conversion_impl.hpp
index 79e9301842..8652a355f1 100644
--- a/include/mbgl/style/conversion_impl.hpp
+++ b/include/mbgl/style/conversion_impl.hpp
@@ -5,6 +5,7 @@
 #include <mbgl/style/expression/image.hpp>
 #include <mbgl/style/layer.hpp>
 #include <mbgl/style/property_value.hpp>
+#include <mbgl/style/rotation.hpp>
 #include <mbgl/style/transition_options.hpp>
 #include <mbgl/util/feature.hpp>
 #include <mbgl/util/geojson.hpp>
@@ -343,6 +344,11 @@ struct ValueFactory<Position> {
     }
 };
 
+template <>
+struct ValueFactory<Rotation> {
+    static Value make(const Rotation& rotation) { return {rotation.getAngle()}; }
+};
+
 template <typename T>
 Value makeValue(T&& arg) {
     return ValueFactory<std::decay_t<T>>::make(std::forward<T>(arg));
diff --git a/include/mbgl/style/expression/value.hpp b/include/mbgl/style/expression/value.hpp
index 902f5ae209..6f12bb9336 100644
--- a/include/mbgl/style/expression/value.hpp
+++ b/include/mbgl/style/expression/value.hpp
@@ -5,6 +5,7 @@
 #include <mbgl/style/expression/image.hpp>
 #include <mbgl/style/expression/type.hpp>
 #include <mbgl/style/position.hpp>
+#include <mbgl/style/rotation.hpp>
 #include <mbgl/style/types.hpp>
 #include <mbgl/util/color.hpp>
 #include <mbgl/util/enum.hpp>
@@ -147,6 +148,13 @@ std::vector<optional<T>> fromExpressionValues(const std::vector<optional<Value>>
     return result;
 }
 
+template <>
+struct ValueConverter<Rotation> {
+    static type::Type expressionType() { return type::Number; }
+    static Value toExpressionValue(const mbgl::style::Rotation& value);
+    static optional<Rotation> fromExpressionValue(const Value& v);
+};
+
 } // namespace expression
 } // namespace style
 } // namespace mbgl
diff --git a/include/mbgl/style/layers/background_layer.hpp b/include/mbgl/style/layers/background_layer.hpp
index 9fdfd3ac92..2a46b2fc21 100644
--- a/include/mbgl/style/layers/background_layer.hpp
+++ b/include/mbgl/style/layers/background_layer.hpp
@@ -7,7 +7,6 @@
 #include <mbgl/style/layer.hpp>
 #include <mbgl/style/filter.hpp>
 #include <mbgl/style/property_value.hpp>
-#include <mbgl/style/expression/formatted.hpp>
 #include <mbgl/util/color.hpp>
 
 namespace mbgl {
diff --git a/include/mbgl/style/layers/circle_layer.hpp b/include/mbgl/style/layers/circle_layer.hpp
index dd5b674002..f0e9787caa 100644
--- a/include/mbgl/style/layers/circle_layer.hpp
+++ b/include/mbgl/style/layers/circle_layer.hpp
@@ -7,7 +7,6 @@
 #include <mbgl/style/layer.hpp>
 #include <mbgl/style/filter.hpp>
 #include <mbgl/style/property_value.hpp>
-#include <mbgl/style/expression/formatted.hpp>
 #include <mbgl/util/color.hpp>
 
 namespace mbgl {
diff --git a/include/mbgl/style/layers/fill_extrusion_layer.hpp b/include/mbgl/style/layers/fill_extrusion_layer.hpp
index ca33c6c3f8..3e4973b82c 100644
--- a/include/mbgl/style/layers/fill_extrusion_layer.hpp
+++ b/include/mbgl/style/layers/fill_extrusion_layer.hpp
@@ -7,7 +7,6 @@
 #include <mbgl/style/layer.hpp>
 #include <mbgl/style/filter.hpp>
 #include <mbgl/style/property_value.hpp>
-#include <mbgl/style/expression/formatted.hpp>
 #include <mbgl/util/color.hpp>
 
 namespace mbgl {
diff --git a/include/mbgl/style/layers/fill_layer.hpp b/include/mbgl/style/layers/fill_layer.hpp
index 4a1f09cca0..fb386c4b11 100644
--- a/include/mbgl/style/layers/fill_layer.hpp
+++ b/include/mbgl/style/layers/fill_layer.hpp
@@ -7,7 +7,6 @@
 #include <mbgl/style/layer.hpp>
 #include <mbgl/style/filter.hpp>
 #include <mbgl/style/property_value.hpp>
-#include <mbgl/style/expression/formatted.hpp>
 #include <mbgl/util/color.hpp>
 
 namespace mbgl {
diff --git a/include/mbgl/style/layers/heatmap_layer.hpp b/include/mbgl/style/layers/heatmap_layer.hpp
index 588aaa81df..371e9a8aa4 100644
--- a/include/mbgl/style/layers/heatmap_layer.hpp
+++ b/include/mbgl/style/layers/heatmap_layer.hpp
@@ -8,7 +8,6 @@
 #include <mbgl/style/layer.hpp>
 #include <mbgl/style/filter.hpp>
 #include <mbgl/style/property_value.hpp>
-#include <mbgl/style/expression/formatted.hpp>
 #include <mbgl/util/color.hpp>
 
 namespace mbgl {
diff --git a/include/mbgl/style/layers/hillshade_layer.hpp b/include/mbgl/style/layers/hillshade_layer.hpp
index c501e80b8d..7149fb46dd 100644
--- a/include/mbgl/style/layers/hillshade_layer.hpp
+++ b/include/mbgl/style/layers/hillshade_layer.hpp
@@ -7,7 +7,6 @@
 #include <mbgl/style/layer.hpp>
 #include <mbgl/style/filter.hpp>
 #include <mbgl/style/property_value.hpp>
-#include <mbgl/style/expression/formatted.hpp>
 #include <mbgl/util/color.hpp>
 
 namespace mbgl {
diff --git a/include/mbgl/style/layers/layer.hpp.ejs b/include/mbgl/style/layers/layer.hpp.ejs
index a083829f60..a81aaa9e16 100644
--- a/include/mbgl/style/layers/layer.hpp.ejs
+++ b/include/mbgl/style/layers/layer.hpp.ejs
@@ -15,7 +15,12 @@
 #include <mbgl/style/layer.hpp>
 #include <mbgl/style/filter.hpp>
 #include <mbgl/style/property_value.hpp>
+<% if (type === 'location-indicator') { -%>
+#include <mbgl/style/rotation.hpp>
+<% } -%>
+<% if (type === 'symbol') { -%>
 #include <mbgl/style/expression/formatted.hpp>
+<% } -%>
 #include <mbgl/util/color.hpp>
 
 <% if (type === 'line' || type === 'symbol') { -%>
diff --git a/include/mbgl/style/layers/line_layer.hpp b/include/mbgl/style/layers/line_layer.hpp
index 2186f16669..7d7da47bf9 100644
--- a/include/mbgl/style/layers/line_layer.hpp
+++ b/include/mbgl/style/layers/line_layer.hpp
@@ -8,7 +8,6 @@
 #include <mbgl/style/layer.hpp>
 #include <mbgl/style/filter.hpp>
 #include <mbgl/style/property_value.hpp>
-#include <mbgl/style/expression/formatted.hpp>
 #include <mbgl/util/color.hpp>
 
 #include <vector>
diff --git a/include/mbgl/style/layers/location_indicator_layer.hpp b/include/mbgl/style/layers/location_indicator_layer.hpp
index e9e67c1a20..f112664dab 100644
--- a/include/mbgl/style/layers/location_indicator_layer.hpp
+++ b/include/mbgl/style/layers/location_indicator_layer.hpp
@@ -7,7 +7,7 @@
 #include <mbgl/style/layer.hpp>
 #include <mbgl/style/filter.hpp>
 #include <mbgl/style/property_value.hpp>
-#include <mbgl/style/expression/formatted.hpp>
+#include <mbgl/style/rotation.hpp>
 #include <mbgl/util/color.hpp>
 
 namespace mbgl {
@@ -22,10 +22,6 @@ public:
 
     // Layout properties
 
-    static PropertyValue<float> getDefaultBearing();
-    const PropertyValue<float>& getBearing() const;
-    void setBearing(const PropertyValue<float>&);
-
     static PropertyValue<expression::Image> getDefaultBearingImage();
     const PropertyValue<expression::Image>& getBearingImage() const;
     void setBearingImage(const PropertyValue<expression::Image>&);
@@ -66,6 +62,12 @@ public:
     void setAccuracyRadiusColorTransition(const TransitionOptions&);
     TransitionOptions getAccuracyRadiusColorTransition() const;
 
+    static PropertyValue<Rotation> getDefaultBearing();
+    const PropertyValue<Rotation>& getBearing() const;
+    void setBearing(const PropertyValue<Rotation>&);
+    void setBearingTransition(const TransitionOptions&);
+    TransitionOptions getBearingTransition() const;
+
     static PropertyValue<float> getDefaultBearingImageSize();
     const PropertyValue<float>& getBearingImageSize() const;
     void setBearingImageSize(const PropertyValue<float>&);
diff --git a/include/mbgl/style/layers/raster_layer.hpp b/include/mbgl/style/layers/raster_layer.hpp
index df82c93660..78fa3db23b 100644
--- a/include/mbgl/style/layers/raster_layer.hpp
+++ b/include/mbgl/style/layers/raster_layer.hpp
@@ -7,7 +7,6 @@
 #include <mbgl/style/layer.hpp>
 #include <mbgl/style/filter.hpp>
 #include <mbgl/style/property_value.hpp>
-#include <mbgl/style/expression/formatted.hpp>
 #include <mbgl/util/color.hpp>
 
 namespace mbgl {
diff --git a/include/mbgl/style/rotation.hpp b/include/mbgl/style/rotation.hpp
new file mode 100644
index 0000000000..862ede93b7
--- /dev/null
+++ b/include/mbgl/style/rotation.hpp
@@ -0,0 +1,25 @@
+#pragma once
+
+namespace mbgl {
+namespace style {
+
+// Could be made a template class if needed
+// template <size_t Period>
+// size_t period() const noexcept { return Period; }
+class Rotation {
+public:
+    Rotation() = default;
+    Rotation(double angle_) : angle(angle_) {}
+    double period() const noexcept { return 360.0; }
+    double getAngle() const noexcept { return angle; }
+
+    friend bool operator==(const Rotation& lhs, const Rotation& rhs) { return lhs.angle == rhs.angle; }
+
+    friend bool operator!=(const Rotation& lhs, const Rotation& rhs) { return !(lhs == rhs); }
+
+private:
+    double angle;
+};
+
+} // namespace style
+} // namespace mbgl
diff --git a/include/mbgl/util/interpolate.hpp b/include/mbgl/util/interpolate.hpp
index aff730a0a2..566f2b0a6b 100644
--- a/include/mbgl/util/interpolate.hpp
+++ b/include/mbgl/util/interpolate.hpp
@@ -1,9 +1,10 @@
 #pragma once
 
+#include <mbgl/style/expression/value.hpp>
+#include <mbgl/style/position.hpp>
+#include <mbgl/style/rotation.hpp>
 #include <mbgl/util/color.hpp>
 #include <mbgl/util/range.hpp>
-#include <mbgl/style/position.hpp>
-#include <mbgl/style/expression/value.hpp>
 
 #include <array>
 #include <vector>
@@ -102,6 +103,27 @@ public:
     }
 };
 
+template <>
+struct Interpolator<style::Rotation> {
+public:
+    style::Rotation operator()(const style::Rotation& a, const style::Rotation& b, const double t) {
+        assert(a.period() == b.period());
+        auto period = a.period();
+        auto aAngle = std::fmod(a.getAngle(), period);
+        auto bAngle = std::fmod(b.getAngle(), period);
+
+        if (aAngle - bAngle > period * 0.5) {
+            return {std::fmod(aAngle * (1.0 - t) + (bAngle + period) * t, period)};
+        }
+
+        if (aAngle - bAngle < period * -0.5) {
+            return {std::fmod((aAngle + period) * (1.0 - t) + bAngle * t, period)};
+        }
+
+        return {aAngle * (1.0 - t) + bAngle * t};
+    }
+};
+
 struct Uninterpolated {
     template <class T>
     T operator()(const T& a, const T&, const double) const {
diff --git a/platform/glfw/glfw_view.cpp b/platform/glfw/glfw_view.cpp
index e538d934a3..c65df4d1cb 100644
--- a/platform/glfw/glfw_view.cpp
+++ b/platform/glfw/glfw_view.cpp
@@ -988,7 +988,8 @@ void GLFWView::toggleLocationIndicatorLayer() {
         puckLayer->setAccuracyRadiusColor(
             premultiply(mbgl::Color{0.0, 1.0, 0.0, 0.2})); // Note: these must be fed premultiplied
 
-        puckLayer->setBearing(0);
+        puckLayer->setBearingTransition(mbgl::style::TransitionOptions(mbgl::Duration::zero(), mbgl::Duration::zero()));
+        puckLayer->setBearing(mbgl::style::Rotation(0.0));
         puckLayer->setAccuracyRadiusBorderColor(premultiply(mbgl::Color{0.0, 1.0, 0.2, 0.4}));
         puckLayer->setTopImageSize(24);
         puckLayer->setBearingImageSize(72);
@@ -1038,8 +1039,8 @@ void GLFWView::onWillStartRenderingFrame() {
     puck = static_cast<mbgl::style::LocationIndicatorLayer *>(map->getStyle().getLayer("puck"));
     if (puck) {
         uint64_t ns = mbgl::Clock::now().time_since_epoch().count();
-        const float bearing = float(ns % 2000000000) / 2000000000.0 * 360.0;
-        puck->setBearing(bearing);
+        const double bearing = double(ns % 2000000000) / 2000000000.0 * 360.0;
+        puck->setBearing(mbgl::style::Rotation(bearing));
     }
 #endif
 }
diff --git a/scripts/generate-style-code.js b/scripts/generate-style-code.js
index 08fd1fba19..c9191d59e1 100755
--- a/scripts/generate-style-code.js
+++ b/scripts/generate-style-code.js
@@ -64,6 +64,13 @@ global.evaluatedType = function (property) {
   case 'boolean':
     return 'bool';
   case 'number':
+    // TODO: Check if 'Rotation' should be used for other properties,
+    // such as icon-rotate
+    if (/bearing$/.test(property.name) &&
+        property.period == 360 &&
+        property.units =='degrees') {
+      return 'Rotation';
+    }
     return /location$/.test(property.name) ? 'double' : 'float';
   case 'resolvedImage':
       return 'expression::Image';
diff --git a/scripts/style-spec.js b/scripts/style-spec.js
index c0acbebd91..15a4c7e0dc 100644
--- a/scripts/style-spec.js
+++ b/scripts/style-spec.js
@@ -47,20 +47,6 @@ referenceSpec["layout_location-indicator"] = {
         },
         "doc": "The amount of the perspective compensation, between 0 and 1. A value of 1 produces a location indicator of constant width across the screen. A value of 0 makes it scale naturally according to the viewing projection."
     },
-    "bearing": {
-        "type": "number",
-        "default": "0",
-        "default": 0,
-        "period": 360,
-        "units": "degrees",
-        "property-type": "data-constant",
-        "expression": {
-            "interpolated": false,
-            "parameters": [ ]
-        },
-        "transition": false,
-        "doc": "The bearing of the location indicator."
-    },
     "image-tilt-displacement": {
         "type": "number",
         "property-type": "data-constant",
@@ -77,6 +63,20 @@ referenceSpec["layout_location-indicator"] = {
 };
 
 referenceSpec["paint_location-indicator"] = {
+    "bearing": {
+        "type": "number",
+        "default": "0",
+        "default": 0,
+        "period": 360,
+        "units": "degrees",
+        "property-type": "data-constant",
+        "expression": {
+            "interpolated": false,
+            "parameters": [ ]
+        },
+        "transition": false,
+        "doc": "The bearing of the location indicator."
+    },
     "location": {
         "type": "array",
         "default": [
@@ -176,6 +176,20 @@ referenceSpec["paint_location-indicator"] = {
         },
         "transition": true,
         "doc": "The color for drawing the accuracy radius border. To adjust transparency, set the alpha component of the color accordingly."
+    },
+    "bearing": {
+        "type": "number",
+        "default": "0",
+        "default": 0,
+        "period": 360,
+        "units": "degrees",
+        "property-type": "data-constant",
+        "expression": {
+            "interpolated": false,
+            "parameters": [ ]
+        },
+        "transition": false,
+        "doc": "The bearing of the location indicator."
     }
 };
 
diff --git a/src/mbgl/renderer/layers/render_location_indicator_layer.cpp b/src/mbgl/renderer/layers/render_location_indicator_layer.cpp
index 20c3bb8cfe..94ac46e216 100644
--- a/src/mbgl/renderer/layers/render_location_indicator_layer.cpp
+++ b/src/mbgl/renderer/layers/render_location_indicator_layer.cpp
@@ -714,13 +714,12 @@ void RenderLocationIndicatorLayer::evaluate(const PropertyEvaluationParameters&
     renderImpl->parameters.puckSizePx = evaluated.get<style::BearingImageSize>();
     renderImpl->parameters.puckHatSizePx = evaluated.get<style::TopImageSize>();
     renderImpl->parameters.puckShadowSizePx = evaluated.get<style::ShadowImageSize>();
+    renderImpl->parameters.puckBearing = evaluated.get<style::Bearing>().getAngle();
 
     const std::array<double, 3> pos = evaluated.get<style::Location>();
     renderImpl->parameters.puckPosition = LatLng{pos[0], pos[1]};
 
     // layout
-    if (!layout.get<style::Bearing>().isUndefined())
-        renderImpl->parameters.puckBearing = layout.get<style::Bearing>().asConstant();
     if (!layout.get<style::BearingImage>().isUndefined())
         renderImpl->parameters.puckImagePath = layout.get<style::BearingImage>().asConstant().id();
     if (!layout.get<style::ShadowImage>().isUndefined())
diff --git a/src/mbgl/style/conversion/function.cpp b/src/mbgl/style/conversion/function.cpp
index 6c2bcdf10f..19ad643a23 100644
--- a/src/mbgl/style/conversion/function.cpp
+++ b/src/mbgl/style/conversion/function.cpp
@@ -1,5 +1,6 @@
 #include <mbgl/style/conversion/function.hpp>
 #include <mbgl/style/conversion/position.hpp>
+#include <mbgl/style/conversion/rotation.hpp>
 #include <mbgl/style/conversion_impl.hpp>
 #include <mbgl/style/expression/case.hpp>
 #include <mbgl/style/expression/dsl.hpp>
@@ -159,6 +160,7 @@ template optional<PropertyExpression<Formatted>>
 template optional<PropertyExpression<std::vector<TextWritingModeType>>>
     convertFunctionToExpression<std::vector<TextWritingModeType>>(const Convertible&, Error&, bool);
 template optional<PropertyExpression<Image>> convertFunctionToExpression<Image>(const Convertible&, Error&, bool);
+template optional<PropertyExpression<Rotation>> convertFunctionToExpression<Rotation>(const Convertible&, Error&, bool);
 
 // Ad-hoc Converters for double and int64_t. We should replace float with double wholesale,
 // and promote the int64_t Converter to general use (and it should check that the input is
diff --git a/src/mbgl/style/conversion/property_value.cpp b/src/mbgl/style/conversion/property_value.cpp
index 1a0e686850..2fbeb4dd44 100644
--- a/src/mbgl/style/conversion/property_value.cpp
+++ b/src/mbgl/style/conversion/property_value.cpp
@@ -1,5 +1,6 @@
-#include <mbgl/style/conversion/property_value.hpp>
 #include <mbgl/style/conversion/position.hpp>
+#include <mbgl/style/conversion/property_value.hpp>
+#include <mbgl/style/conversion/rotation.hpp>
 #include <mbgl/style/conversion_impl.hpp>
 
 namespace mbgl {
@@ -107,6 +108,9 @@ mbgl::style::conversion::Converter<PropertyValue<std::array<double, 3>>, void>::
     return r;
 }
 
+template optional<PropertyValue<Rotation>> Converter<PropertyValue<Rotation>>::operator()(
+    conversion::Convertible const&, conversion::Error&, bool, bool) const;
+
 } // namespace conversion
 } // namespace style
 } // namespace mbgl
diff --git a/src/mbgl/style/conversion/rotation.cpp b/src/mbgl/style/conversion/rotation.cpp
new file mode 100644
index 0000000000..11431437dd
--- /dev/null
+++ b/src/mbgl/style/conversion/rotation.cpp
@@ -0,0 +1,20 @@
+#include <mbgl/style/conversion/constant.hpp>
+#include <mbgl/style/conversion/rotation.hpp>
+#include <mbgl/style/conversion_impl.hpp>
+
+namespace mbgl {
+namespace style {
+namespace conversion {
+
+optional<style::Rotation> Converter<style::Rotation>::operator()(const Convertible& value, Error& error) const {
+    optional<double> converted = toDouble(value);
+    if (!converted) {
+        error.message = "value must be a number";
+        return nullopt;
+    }
+    return {*converted};
+}
+
+} // namespace conversion
+} // namespace style
+} // namespace mbgl
diff --git a/src/mbgl/style/expression/value.cpp b/src/mbgl/style/expression/value.cpp
index 9f40d17b02..2ceac4588b 100644
--- a/src/mbgl/style/expression/value.cpp
+++ b/src/mbgl/style/expression/value.cpp
@@ -269,6 +269,15 @@ optional<Position> ValueConverter<Position>::fromExpressionValue(const Value& v)
     return pos ? optional<Position>(Position(*pos)) : optional<Position>();
 }
 
+Value ValueConverter<Rotation>::toExpressionValue(const mbgl::style::Rotation& value) {
+    return ValueConverter<float>::toExpressionValue(value.getAngle());
+}
+
+optional<Rotation> ValueConverter<Rotation>::fromExpressionValue(const Value& v) {
+    auto angle = ValueConverter<float>::fromExpressionValue(v);
+    return angle ? optional<Rotation>(Rotation(*angle)) : optional<Rotation>();
+}
+
 template <typename T>
 Value ValueConverter<T, std::enable_if_t< std::is_enum<T>::value >>::toExpressionValue(const T& value) {
     return std::string(Enum<T>::toString(value));
@@ -317,6 +326,7 @@ template struct ValueConverter<std::array<double, 3>>;
 // layout/paint property types
 template type::Type valueTypeToExpressionType<float>();
 template type::Type valueTypeToExpressionType<Position>();
+template type::Type valueTypeToExpressionType<Rotation>();
 
 template type::Type valueTypeToExpressionType<std::array<float, 2>>();
 template struct ValueConverter<std::array<float, 2>>;
diff --git a/src/mbgl/style/layers/location_indicator_layer.cpp b/src/mbgl/style/layers/location_indicator_layer.cpp
index 03b826cc18..178fd104ad 100644
--- a/src/mbgl/style/layers/location_indicator_layer.cpp
+++ b/src/mbgl/style/layers/location_indicator_layer.cpp
@@ -63,21 +63,6 @@ void LocationIndicatorLayer::Impl::stringifyLayout(rapidjson::Writer<rapidjson::
 
 // Layout properties
 
-PropertyValue<float> LocationIndicatorLayer::getDefaultBearing() {
-    return Bearing::defaultValue();
-}
-
-const PropertyValue<float>& LocationIndicatorLayer::getBearing() const {
-    return impl().layout.get<Bearing>();
-}
-
-void LocationIndicatorLayer::setBearing(const PropertyValue<float>& value) {
-    if (value == getBearing()) return;
-    auto impl_ = mutableImpl();
-    impl_->layout.get<Bearing>() = value;
-    baseImpl = std::move(impl_);
-    observer->onLayerChanged(*this);
-}
 PropertyValue<expression::Image> LocationIndicatorLayer::getDefaultBearingImage() {
     return BearingImage::defaultValue();
 }
@@ -237,6 +222,33 @@ TransitionOptions LocationIndicatorLayer::getAccuracyRadiusColorTransition() con
     return impl().paint.template get<AccuracyRadiusColor>().options;
 }
 
+PropertyValue<Rotation> LocationIndicatorLayer::getDefaultBearing() {
+    return {0};
+}
+
+const PropertyValue<Rotation>& LocationIndicatorLayer::getBearing() const {
+    return impl().paint.template get<Bearing>().value;
+}
+
+void LocationIndicatorLayer::setBearing(const PropertyValue<Rotation>& value) {
+    if (value == getBearing())
+        return;
+    auto impl_ = mutableImpl();
+    impl_->paint.template get<Bearing>().value = value;
+    baseImpl = std::move(impl_);
+    observer->onLayerChanged(*this);
+}
+
+void LocationIndicatorLayer::setBearingTransition(const TransitionOptions& options) {
+    auto impl_ = mutableImpl();
+    impl_->paint.template get<Bearing>().options = options;
+    baseImpl = std::move(impl_);
+}
+
+TransitionOptions LocationIndicatorLayer::getBearingTransition() const {
+    return impl().paint.template get<Bearing>().options;
+}
+
 PropertyValue<float> LocationIndicatorLayer::getDefaultBearingImageSize() {
     return {0};
 }
@@ -349,12 +361,13 @@ using namespace conversion;
 
 namespace {
 
-constexpr uint8_t kPaintPropertyCount = 14u;
+constexpr uint8_t kPaintPropertyCount = 16u;
 
 enum class Property : uint8_t {
     AccuracyRadius,
     AccuracyRadiusBorderColor,
     AccuracyRadiusColor,
+    Bearing,
     BearingImageSize,
     Location,
     ShadowImageSize,
@@ -362,12 +375,12 @@ enum class Property : uint8_t {
     AccuracyRadiusTransition,
     AccuracyRadiusBorderColorTransition,
     AccuracyRadiusColorTransition,
+    BearingTransition,
     BearingImageSizeTransition,
     LocationTransition,
     ShadowImageSizeTransition,
     TopImageSizeTransition,
-    Bearing = kPaintPropertyCount,
-    BearingImage,
+    BearingImage = kPaintPropertyCount,
     ImageTiltDisplacement,
     PerspectiveCompensation,
     ShadowImage,
@@ -383,6 +396,7 @@ MAPBOX_ETERNAL_CONSTEXPR const auto layerProperties = mapbox::eternal::hash_map<
     {{"accuracy-radius", toUint8(Property::AccuracyRadius)},
      {"accuracy-radius-border-color", toUint8(Property::AccuracyRadiusBorderColor)},
      {"accuracy-radius-color", toUint8(Property::AccuracyRadiusColor)},
+     {"bearing", toUint8(Property::Bearing)},
      {"bearing-image-size", toUint8(Property::BearingImageSize)},
      {"location", toUint8(Property::Location)},
      {"shadow-image-size", toUint8(Property::ShadowImageSize)},
@@ -390,11 +404,11 @@ MAPBOX_ETERNAL_CONSTEXPR const auto layerProperties = mapbox::eternal::hash_map<
      {"accuracy-radius-transition", toUint8(Property::AccuracyRadiusTransition)},
      {"accuracy-radius-border-color-transition", toUint8(Property::AccuracyRadiusBorderColorTransition)},
      {"accuracy-radius-color-transition", toUint8(Property::AccuracyRadiusColorTransition)},
+     {"bearing-transition", toUint8(Property::BearingTransition)},
      {"bearing-image-size-transition", toUint8(Property::BearingImageSizeTransition)},
      {"location-transition", toUint8(Property::LocationTransition)},
      {"shadow-image-size-transition", toUint8(Property::ShadowImageSizeTransition)},
      {"top-image-size-transition", toUint8(Property::TopImageSizeTransition)},
-     {"bearing", toUint8(Property::Bearing)},
      {"bearing-image", toUint8(Property::BearingImage)},
      {"image-tilt-displacement", toUint8(Property::ImageTiltDisplacement)},
      {"perspective-compensation", toUint8(Property::PerspectiveCompensation)},
@@ -409,6 +423,8 @@ StyleProperty getLayerProperty(const LocationIndicatorLayer& layer, Property pro
             return makeStyleProperty(layer.getAccuracyRadiusBorderColor());
         case Property::AccuracyRadiusColor:
             return makeStyleProperty(layer.getAccuracyRadiusColor());
+        case Property::Bearing:
+            return makeStyleProperty(layer.getBearing());
         case Property::BearingImageSize:
             return makeStyleProperty(layer.getBearingImageSize());
         case Property::Location:
@@ -423,6 +439,8 @@ StyleProperty getLayerProperty(const LocationIndicatorLayer& layer, Property pro
             return makeStyleProperty(layer.getAccuracyRadiusBorderColorTransition());
         case Property::AccuracyRadiusColorTransition:
             return makeStyleProperty(layer.getAccuracyRadiusColorTransition());
+        case Property::BearingTransition:
+            return makeStyleProperty(layer.getBearingTransition());
         case Property::BearingImageSizeTransition:
             return makeStyleProperty(layer.getBearingImageSizeTransition());
         case Property::LocationTransition:
@@ -431,8 +449,6 @@ StyleProperty getLayerProperty(const LocationIndicatorLayer& layer, Property pro
             return makeStyleProperty(layer.getShadowImageSizeTransition());
         case Property::TopImageSizeTransition:
             return makeStyleProperty(layer.getTopImageSizeTransition());
-        case Property::Bearing:
-            return makeStyleProperty(layer.getBearing());
         case Property::BearingImage:
             return makeStyleProperty(layer.getBearingImage());
         case Property::ImageTiltDisplacement:
@@ -475,7 +491,7 @@ optional<Error> LocationIndicatorLayer::setPropertyInternal(const std::string& n
     auto property = static_cast<Property>(it->second);
 
     if (property == Property::AccuracyRadius || property == Property::BearingImageSize ||
-        property == Property::ShadowImageSize || property == Property::TopImageSize || property == Property::Bearing ||
+        property == Property::ShadowImageSize || property == Property::TopImageSize ||
         property == Property::ImageTiltDisplacement || property == Property::PerspectiveCompensation) {
         Error error;
         const auto& typedValue = convert<PropertyValue<float>>(value, error, false, false);
@@ -503,11 +519,6 @@ optional<Error> LocationIndicatorLayer::setPropertyInternal(const std::string& n
             return nullopt;
         }
 
-        if (property == Property::Bearing) {
-            setBearing(*typedValue);
-            return nullopt;
-        }
-
         if (property == Property::ImageTiltDisplacement) {
             setImageTiltDisplacement(*typedValue);
             return nullopt;
@@ -535,6 +546,16 @@ optional<Error> LocationIndicatorLayer::setPropertyInternal(const std::string& n
             return nullopt;
         }
     }
+    if (property == Property::Bearing) {
+        Error error;
+        const auto& typedValue = convert<PropertyValue<Rotation>>(value, error, false, false);
+        if (!typedValue) {
+            return error;
+        }
+
+        setBearing(*typedValue);
+        return nullopt;
+    }
     if (property == Property::Location) {
         Error error;
         const auto& typedValue = convert<PropertyValue<std::array<double, 3>>>(value, error, false, false);
@@ -589,6 +610,11 @@ optional<Error> LocationIndicatorLayer::setPropertyInternal(const std::string& n
         return nullopt;
     }
 
+    if (property == Property::BearingTransition) {
+        setBearingTransition(*transition);
+        return nullopt;
+    }
+
     if (property == Property::BearingImageSizeTransition) {
         setBearingImageSizeTransition(*transition);
         return nullopt;
diff --git a/src/mbgl/style/layers/location_indicator_layer_properties.hpp b/src/mbgl/style/layers/location_indicator_layer_properties.hpp
index d1f0879f74..d73ce33eb9 100644
--- a/src/mbgl/style/layers/location_indicator_layer_properties.hpp
+++ b/src/mbgl/style/layers/location_indicator_layer_properties.hpp
@@ -16,11 +16,6 @@
 namespace mbgl {
 namespace style {
 
-struct Bearing : LayoutProperty<float> {
-    static constexpr const char *name() { return "bearing"; }
-    static float defaultValue() { return 0; }
-};
-
 struct BearingImage : LayoutProperty<expression::Image> {
     static constexpr const char *name() { return "bearing-image"; }
     static expression::Image defaultValue() { return {}; }
@@ -58,6 +53,10 @@ struct AccuracyRadiusColor : PaintProperty<Color> {
     static Color defaultValue() { return Color::white(); }
 };
 
+struct Bearing : PaintProperty<Rotation> {
+    static Rotation defaultValue() { return 0; }
+};
+
 struct BearingImageSize : PaintProperty<float> {
     static float defaultValue() { return 0; }
 };
@@ -75,7 +74,6 @@ struct TopImageSize : PaintProperty<float> {
 };
 
 class LocationIndicatorLayoutProperties : public Properties<
-    Bearing,
     BearingImage,
     ImageTiltDisplacement,
     PerspectiveCompensation,
@@ -87,6 +85,7 @@ class LocationIndicatorPaintProperties : public Properties<
     AccuracyRadius,
     AccuracyRadiusBorderColor,
     AccuracyRadiusColor,
+    Bearing,
     BearingImageSize,
     Location,
     ShadowImageSize,