5 files changed, 38 insertions, 41 deletions

diff --git a/src/mbgl/map/map.cpp b/src/mbgl/map/map.cpp
index d7a1020262..3bc4c9f8d9 100644
--- a/src/mbgl/map/map.cpp
+++ b/src/mbgl/map/map.cpp
@@ -181,7 +181,7 @@ LatLng Map::getLatLng(const EdgeInsets& padding) const {
 
 void Map::resetPosition(const EdgeInsets& padding) {
     impl->cameraMutated = true;
-    impl->transform.jumpTo(CameraOptions().withCenter(LatLng()).withPadding(padding).withZoom(0.0).withAngle(0.0).withPitch(0.0));
+    impl->transform.jumpTo(CameraOptions().withCenter(LatLng()).withPadding(padding).withZoom(0.0).withBearing(0.0).withPitch(0.0));
     impl->onUpdate();
 }
 
@@ -260,11 +260,11 @@ CameraOptions Map::cameraForLatLngs(const std::vector<LatLng>& latLngs, const Ed
     Transform transform(impl->transform.getState());
 
     if (bearing || pitch) {
-        transform.jumpTo(CameraOptions().withAngle(bearing).withPitch(pitch));
+        transform.jumpTo(CameraOptions().withBearing(bearing).withPitch(pitch));
     }
 
     return mbgl::cameraForLatLngs(latLngs, transform, padding)
-        .withAngle(-transform.getAngle() * util::RAD2DEG)
+        .withBearing(-transform.getBearing() * util::RAD2DEG)
         .withPitch(transform.getPitch() * util::RAD2DEG);
 }
 
diff --git a/src/mbgl/map/transform.cpp b/src/mbgl/map/transform.cpp
index 8065bc17ce..96aa5d2f4a 100644
--- a/src/mbgl/map/transform.cpp
+++ b/src/mbgl/map/transform.cpp
@@ -87,10 +87,10 @@ void Transform::easeTo(const CameraOptions& camera, const AnimationOptions& anim
     const LatLng& unwrappedLatLng = camera.center.value_or(startLatLng);
     const LatLng& latLng = state.bounds ? unwrappedLatLng : unwrappedLatLng.wrapped();
     double zoom = camera.zoom.value_or(getZoom());
-    double angle = camera.angle ? -*camera.angle * util::DEG2RAD : getAngle();
+    double bearing = camera.bearing ? -*camera.bearing * util::DEG2RAD : getBearing();
     double pitch = camera.pitch ? *camera.pitch * util::DEG2RAD : getPitch();
 
-    if (std::isnan(zoom) || std::isnan(angle) || std::isnan(pitch)) {
+    if (std::isnan(zoom) || std::isnan(bearing) || std::isnan(pitch)) {
         return;
     }
 
@@ -119,17 +119,17 @@ void Transform::easeTo(const CameraOptions& camera, const AnimationOptions& anim
     pitch = util::clamp(pitch, state.min_pitch, state.max_pitch);
 
     // Minimize rotation by taking the shorter path around the circle.
-    angle = _normalizeAngle(angle, state.angle);
-    state.angle = _normalizeAngle(state.angle, angle);
+    bearing = _normalizeAngle(bearing, state.bearing);
+    state.bearing = _normalizeAngle(state.bearing, bearing);
 
     Duration duration = animation.duration ? *animation.duration : Duration::zero();
 
     const double startScale = state.scale;
-    const double startAngle = state.angle;
+    const double startBearing = state.bearing;
     const double startPitch = state.pitch;
     state.panning = unwrappedLatLng != startLatLng;
     state.scaling = scale != startScale;
-    state.rotating = angle != startAngle;
+    state.rotating = bearing != startBearing;
 
     startTransition(camera, animation, [=](double t) {
         Point<double> framePoint = util::interpolate(startPoint, endPoint, t);
@@ -137,8 +137,8 @@ void Transform::easeTo(const CameraOptions& camera, const AnimationOptions& anim
         double frameScale = util::interpolate(startScale, scale, t);
         state.setLatLngZoom(frameLatLng, state.scaleZoom(frameScale));
 
-        if (angle != startAngle) {
-            state.angle = util::wrap(util::interpolate(startAngle, angle, t), -M_PI, M_PI);
+        if (bearing != startBearing) {
+            state.bearing = util::wrap(util::interpolate(startBearing, bearing, t), -M_PI, M_PI);
         }
         if (pitch != startPitch) {
             state.pitch = util::interpolate(startPitch, pitch, t);
@@ -162,10 +162,10 @@ void Transform::flyTo(const CameraOptions &camera, const AnimationOptions &anima
     const EdgeInsets& padding = camera.padding;
     const LatLng& latLng = camera.center.value_or(getLatLng(padding, LatLng::Unwrapped)).wrapped();
     double zoom = camera.zoom.value_or(getZoom());
-    double angle = camera.angle ? -*camera.angle * util::DEG2RAD : getAngle();
+    double bearing = camera.bearing ? -*camera.bearing * util::DEG2RAD : getBearing();
     double pitch = camera.pitch ? *camera.pitch * util::DEG2RAD : getPitch();
 
-    if (std::isnan(zoom) || std::isnan(angle) || std::isnan(pitch) || state.size.isEmpty()) {
+    if (std::isnan(zoom) || std::isnan(bearing) || std::isnan(pitch) || state.size.isEmpty()) {
         return;
     }
 
@@ -184,11 +184,11 @@ void Transform::flyTo(const CameraOptions &camera, const AnimationOptions &anima
     pitch = util::clamp(pitch, state.min_pitch, state.max_pitch);
 
     // Minimize rotation by taking the shorter path around the circle.
-    angle = _normalizeAngle(angle, state.angle);
-    state.angle = _normalizeAngle(state.angle, angle);
+    bearing = _normalizeAngle(bearing, state.bearing);
+    state.bearing = _normalizeAngle(state.bearing, bearing);
 
     const double startZoom = state.scaleZoom(state.scale);
-    const double startAngle = state.angle;
+    const double startBearing = state.bearing;
     const double startPitch = state.pitch;
 
     /// w₀: Initial visible span, measured in pixels at the initial scale.
@@ -277,7 +277,7 @@ void Transform::flyTo(const CameraOptions &camera, const AnimationOptions &anima
     const double startScale = state.scale;
     state.panning = true;
     state.scaling = true;
-    state.rotating = angle != startAngle;
+    state.rotating = bearing != startBearing;
 
     startTransition(camera, animation, [=](double k) {
         /// s: The distance traveled along the flight path, measured in
@@ -298,8 +298,8 @@ void Transform::flyTo(const CameraOptions &camera, const AnimationOptions &anima
         LatLng frameLatLng = Projection::unproject(framePoint, startScale);
         state.setLatLngZoom(frameLatLng, frameZoom);
 
-        if (angle != startAngle) {
-            state.angle = util::wrap(util::interpolate(startAngle, angle, k), -M_PI, M_PI);
+        if (bearing != startBearing) {
+            state.bearing = util::wrap(util::interpolate(startBearing, bearing, k), -M_PI, M_PI);
         }
         if (pitch != startPitch) {
             state.pitch = util::interpolate(startPitch, pitch, k);
@@ -371,7 +371,7 @@ void Transform::setMaxPitch(double maxPitch) {
     state.setMaxPitch(maxPitch);
 }
 
-#pragma mark - Angle
+#pragma mark - Bearing
 
 void Transform::rotateBy(const ScreenCoordinate& first, const ScreenCoordinate& second,  const AnimationOptions& animation) {
     ScreenCoordinate center = getScreenCoordinate();
@@ -382,17 +382,17 @@ void Transform::rotateBy(const ScreenCoordinate& first, const ScreenCoordinate&
     // in the direction of the click.
     if (distance < 200) {
         const double heightOffset = -200;
-        const double rotateAngle = std::atan2(offset.y, offset.x);
-        center.x = first.x + std::cos(rotateAngle) * heightOffset;
-        center.y = first.y + std::sin(rotateAngle) * heightOffset;
+        const double rotateBearing = std::atan2(offset.y, offset.x);
+        center.x = first.x + std::cos(rotateBearing) * heightOffset;
+        center.y = first.y + std::sin(rotateBearing) * heightOffset;
     }
 
-    const double angle = -(state.angle + util::angle_between(first - center, second - center)) * util::RAD2DEG;
-    easeTo(CameraOptions().withAngle(angle), animation);
+    const double bearing = -(state.bearing + util::angle_between(first - center, second - center)) * util::RAD2DEG;
+    easeTo(CameraOptions().withBearing(bearing), animation);
 }
 
-double Transform::getAngle() const {
-    return state.angle;
+double Transform::getBearing() const {
+    return state.bearing;
 }
 
 #pragma mark - Pitch
diff --git a/src/mbgl/map/transform.hpp b/src/mbgl/map/transform.hpp
index da62a3f04e..cf342181b1 100644
--- a/src/mbgl/map/transform.hpp
+++ b/src/mbgl/map/transform.hpp
@@ -62,13 +62,10 @@ public:
     /** Returns the zoom level. */
     double getZoom() const;
 
-    // Angle
+    // Bearing
 
     void rotateBy(const ScreenCoordinate& first, const ScreenCoordinate& second, const AnimationOptions& = {});
-    /** Returns the angle of rotation.
-        @return The angle of rotation, measured in radians counterclockwise from
-            true north. */
-    double getAngle() const;
+    double getBearing() const;
 
     // Pitch
 
diff --git a/src/mbgl/map/transform_state.cpp b/src/mbgl/map/transform_state.cpp
index 778d4bd7e7..e911067c5b 100644
--- a/src/mbgl/map/transform_state.cpp
+++ b/src/mbgl/map/transform_state.cpp
@@ -61,7 +61,7 @@ void TransformState::getProjMatrix(mat4& projMatrix, uint16_t nearZ, bool aligne
         default: matrix::rotate_x(projMatrix, projMatrix, getPitch()); break;
     }
 
-    matrix::rotate_z(projMatrix, projMatrix, getAngle() + getNorthOrientationAngle());
+    matrix::rotate_z(projMatrix, projMatrix, getBearing() + getNorthOrientationAngle());
 
     const double dx = pixel_x() - size.width / 2.0f, dy = pixel_y() - size.height / 2.0f;
     matrix::translate(projMatrix, projMatrix, dx, dy, 0);
@@ -86,10 +86,10 @@ void TransformState::getProjMatrix(mat4& projMatrix, uint16_t nearZ, bool aligne
     // it is always <= 0.5 pixels.
     if (aligned) {
         const float xShift = float(size.width % 2) / 2, yShift = float(size.height % 2) / 2;
-        const double angleCos = std::cos(angle), angleSin = std::sin(angle);
+        const double bearingCos = std::cos(bearing), bearingSin = std::sin(bearing);
         double devNull;
-        const float dxa = -std::modf(dx, &devNull) + angleCos * xShift + angleSin * yShift;
-        const float dya = -std::modf(dy, &devNull) + angleCos * yShift + angleSin * xShift;
+        const float dxa = -std::modf(dx, &devNull) + bearingCos * xShift + bearingSin * yShift;
+        const float dya = -std::modf(dy, &devNull) + bearingCos * yShift + bearingSin * xShift;
         matrix::translate(projMatrix, projMatrix, dxa > 0.5 ? dxa - 1 : dxa, dya > 0.5 ? dya - 1 : dya, 0);
     }
 }
@@ -145,7 +145,7 @@ CameraOptions TransformState::getCameraOptions(const EdgeInsets& padding) const
         .withCenter(center)
         .withPadding(padding)
         .withZoom(getZoom())
-        .withAngle(-angle * util::RAD2DEG)
+        .withBearing(-bearing * util::RAD2DEG)
         .withPitch(pitch * util::RAD2DEG);
 }
 
@@ -243,8 +243,8 @@ double TransformState::getMaxPitch() const {
 
 #pragma mark - Rotation
 
-float TransformState::getAngle() const {
-    return angle;
+float TransformState::getBearing() const {
+    return bearing;
 }
 
 float TransformState::getFieldOfView() const {
diff --git a/src/mbgl/map/transform_state.hpp b/src/mbgl/map/transform_state.hpp
index fe716d8ea8..be7c300803 100644
--- a/src/mbgl/map/transform_state.hpp
+++ b/src/mbgl/map/transform_state.hpp
@@ -67,7 +67,7 @@ public:
     double getMaxPitch() const;
 
     // Rotation
-    float getAngle() const;
+    float getBearing() const;
     float getFieldOfView() const;
     float getCameraToCenterDistance() const;
     float getPitch() const;
@@ -131,7 +131,7 @@ private:
 
     // map position
     double x = 0, y = 0;
-    double angle = 0;
+    double bearing = 0;
     double scale = 1;
     // This fov value is somewhat arbitrary. The altitude of the camera used
     // to be defined as 1.5 screen heights above the ground, which was an