CameraOptions

Plumbed camera options all the way through to MGLMapView. Added a method that lets you specify a direction in addition to center point and zoom level.

Added Map::jumpTo() for parity with mapbox-gl-js. Replaced usage of Map::setLatLng() and Map::setLatLngZoom() with Map::jumpTo() or Map::easeTo() within MGLMapView. Replaced MGLMapView.pitch with MGLMapCamera for setting all supported degrees of freedom simultaneously. Simultaneously move and rotate with course.

Support customizable timing functions on iOS.

iosapp now persists an archived MGLMapCamera instead of separate viewpoint properties and also synchronizes user defaults on termination. This change implements persistence entirely in Objective-C, eliminating the use of the Objective-C++ implementation.

Fixes #1643, fixes #1834. Ref #1581.

gyp/platform-ios.gypi

@@ -20,6 +20,8 @@
         '../include/mbgl/ios/Mapbox.h',
         '../platform/ios/MGLMapboxEvents.h',
         '../platform/ios/MGLMapboxEvents.m',
+        '../include/mbgl/ios/MGLMapCamera.h',
+        '../platform/ios/MGLMapCamera.mm',
         '../include/mbgl/ios/MGLMapView.h',
         '../include/mbgl/ios/MGLMapView+IBAdditions.h',
         '../platform/ios/MGLMapView.mm',

include/mbgl/ios/MGLMapCamera.h

@@ -0,0 +1,36 @@
+#import "Mapbox.h"
+
+#pragma once
+
+NS_ASSUME_NONNULL_BEGIN
+
+/** An `MGLMapCamera` object represents a viewpoint from which the user observes some point on an `MGLMapView`. */
+@interface MGLMapCamera : NSObject <NSSecureCoding, NSCopying>
+
+/** Coordinate at the center of the map view. */
+@property (nonatomic) CLLocationCoordinate2D centerCoordinate;
+
+/** Heading measured in degrees clockwise from true north. */
+@property (nonatomic) CLLocationDirection heading;
+
+/** Pitch toward the horizon measured in degrees, with 0 degrees resulting in a two-dimensional map. */
+@property (nonatomic) CGFloat pitch;
+
+/** Meters above ground level. */
+@property (nonatomic) CLLocationDistance altitude;
+
+/** Returns a new camera with all properties set to 0. */
++ (instancetype)camera;
+
++ (instancetype)cameraLookingAtCenterCoordinate:(CLLocationCoordinate2D)centerCoordinate
+                              fromEyeCoordinate:(CLLocationCoordinate2D)eyeCoordinate
+                                    eyeAltitude:(CLLocationDistance)eyeAltitude;
+
++ (instancetype)cameraLookingAtCenterCoordinate:(CLLocationCoordinate2D)centerCoordinate
+                                   fromDistance:(CLLocationDistance)distance
+                                          pitch:(CGFloat)pitch
+                                        heading:(CLLocationDirection)heading;
+
+@end
+
+NS_ASSUME_NONNULL_END

include/mbgl/ios/MGLMapView.h

@@ -1,4 +1,5 @@
 #import "MGLGeometry.h"
+#import "MGLMapCamera.h"
 
 #import <UIKit/UIKit.h>
 #import <CoreLocation/CoreLocation.h>
@@ -6,6 +7,7 @@
 NS_ASSUME_NONNULL_BEGIN
 
 @class MGLAnnotationImage;
+@class MGLMapCamera;
 @class MGLUserLocation;
 @class MGLPolyline;
 @class MGLPolygon;
@@ -136,6 +138,8 @@ IB_DESIGNABLE
 *   @param animated Specify `YES` if you want the map view to animate scrolling and zooming to the new location or `NO` if you want the map to display the new location immediately. */
 - (void)setCenterCoordinate:(CLLocationCoordinate2D)centerCoordinate zoomLevel:(double)zoomLevel animated:(BOOL)animated;
 
+- (void)setCenterCoordinate:(CLLocationCoordinate2D)centerCoordinate zoomLevel:(double)zoomLevel direction:(CLLocationDirection)direction animated:(BOOL)animated;
+
 /** The coordinate bounds visible in the receiver’s viewport.
 *   
 *   Changing the value of this property updates the receiver immediately. If you want to animate the change, call `setVisibleCoordinateBounds:animated:` instead. */
@@ -181,19 +185,19 @@ IB_DESIGNABLE
 /** Resets the map rotation to a northern heading. */
 - (IBAction)resetNorth;
 
-/** The pitch of the map (measured in degrees).
- *
- *   The default value `0` shows a completely flat map. Maximum value is `60`. */
-@property (nonatomic) double pitch;
+/** A camera representing the current viewpoint of the map. */
+@property (nonatomic, copy) MGLMapCamera *camera;
 
-/** Changes the pitch of the map.
- *   @param pitch The pitch of the map (measured in degrees) relative to top-down.
- *
- *   Changing the pitch tilts the map without changing the current center coordinate or zoom level. */
-- (void)setPitch:(double)pitch;
+/** Moves the viewpoint to a different location with respect to the map with an optional transition animation.
+*   @param camera The new viewpoint.
+*   @param animated Specify `YES` if you want the map view to animate the change to the new viewpoint or `NO` if you want the map to display the new viewpoint immediately. */
+- (void)setCamera:(MGLMapCamera *)camera animated:(BOOL)animated;
 
-/** Resets the map pitch to head-on. */
-- (IBAction)resetPitch;
+/** Moves the viewpoint to a different location with respect to the map with an optional transition duration and timing function.
+*   @param camera The new viewpoint.
+*   @param duration The amount of time, measured in seconds, that the transition animation should take. Specify `0` to jump to the new viewpoint instantaneously.
+*   @param function A timing function used for the animation. Set this parameter to `nil` for a transition that matches most system animations. If the duration is `0`, this parameter is ignored. */
+- (void)setCamera:(MGLMapCamera *)camera withDuration:(NSTimeInterval)duration animationTimingFunction:(nullable CAMediaTimingFunction *)function;
 
 #pragma mark - Converting Map Coordinates
 

include/mbgl/ios/Mapbox.h

@@ -1,6 +1,7 @@
 #import "MGLAccountManager.h"
 #import "MGLAnnotation.h"
 #import "MGLAnnotationImage.h"
+#import "MGLMapCamera.h"
 #import "MGLGeometry.h"
 #import "MGLMapView.h"
 #import "MGLMultiPoint.h"

include/mbgl/map/camera.hpp

@@ -0,0 +1,22 @@
+#ifndef MBGL_MAP_CAMERA
+#define MBGL_MAP_CAMERA
+
+#include <mbgl/util/geo.hpp>
+#include <mbgl/util/optional.hpp>
+#include <mbgl/util/chrono.hpp>
+#include <mbgl/util/unitbezier.hpp>
+
+namespace mbgl {
+
+struct CameraOptions {
+    mapbox::util::optional<LatLng> center;
+    mapbox::util::optional<double> zoom;
+    mapbox::util::optional<double> angle;
+    mapbox::util::optional<double> pitch;
+    mapbox::util::optional<Duration> duration;
+    mapbox::util::optional<mbgl::util::UnitBezier> easing;
+};
+
+}
+
+#endif /* MBGL_MAP_CAMERA */

include/mbgl/map/map.hpp

@@ -2,6 +2,7 @@
 #define MBGL_MAP_MAP
 
 #include <mbgl/util/chrono.hpp>
+#include <mbgl/map/camera.hpp>
 #include <mbgl/map/update.hpp>
 #include <mbgl/map/mode.hpp>
 #include <mbgl/util/geo.hpp>
@@ -94,6 +95,10 @@ public:
     void cancelTransitions();
     void setGestureInProgress(bool);
 
+    // Camera
+    void jumpTo(CameraOptions options);
+    void easeTo(CameraOptions options);
+
     // Position
     void moveBy(double dx, double dy, const Duration& = Duration::zero());
     void setLatLng(LatLng latLng, const Duration& = Duration::zero());
@@ -107,8 +112,8 @@ public:
     void setZoom(double zoom, const Duration& = Duration::zero());
     double getZoom() const;
     void setLatLngZoom(LatLng latLng, double zoom, const Duration& = Duration::zero());
-    void fitBounds(LatLngBounds bounds, EdgeInsets padding, const Duration& duration = Duration::zero());
-    void fitBounds(AnnotationSegment segment, EdgeInsets padding, const Duration& duration = Duration::zero());
+    CameraOptions cameraForLatLngBounds(LatLngBounds bounds, EdgeInsets padding);
+    CameraOptions cameraForLatLngs(std::vector<LatLng> latLngs, EdgeInsets padding);
     void resetZoom();
     double getMinZoom() const;
     double getMaxZoom() const;
@@ -121,7 +126,7 @@ public:
     void resetNorth();
 
     // Pitch
-    void setPitch(double pitch);
+    void setPitch(double pitch, const Duration& = Duration::zero());
     double getPitch() const;
 
     // Size

ios/app/MBXViewController.mm

@@ -2,8 +2,6 @@
 
 #import <mbgl/ios/Mapbox.h>
 
-#import <mbgl/platform/darwin/settings_nsuserdefaults.hpp>
-
 #import <CoreLocation/CoreLocation.h>
 
 static UIColor *const kTintColor = [UIColor colorWithRed:0.120 green:0.550 blue:0.670 alpha:1.000];
@@ -26,10 +24,20 @@ static NSUInteger const kStyleVersion = 8;
 
 @implementation MBXViewController
 
-mbgl::Settings_NSUserDefaults *settings = nullptr;
-
 #pragma mark - Setup
 
++ (void)initialize
+{
+    if (self == [MBXViewController class])
+    {
+        [[NSUserDefaults standardUserDefaults] registerDefaults:@{
+            @"userTrackingMode": @(MGLUserTrackingModeNone),
+            @"showsUserLocation": @NO,
+            @"debug": @NO,
+        }];
+    }
+}
+
 - (id)init
 {
     self = [super init];
@@ -38,6 +46,7 @@ mbgl::Settings_NSUserDefaults *settings = nullptr;
     {
         [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(saveState:) name:UIApplicationDidEnterBackgroundNotification object:nil];
         [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(restoreState:) name:UIApplicationWillEnterForegroundNotification object:nil];
+        [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(saveState:) name:UIApplicationWillTerminateNotification object:nil];
     }
 
     return self;
@@ -73,7 +82,6 @@ mbgl::Settings_NSUserDefaults *settings = nullptr;
                                                                              target:self
                                                                              action:@selector(locateUser)];
 
-    settings = new mbgl::Settings_NSUserDefaults();
     [self restoreState:nil];
 
     if ( ! settings->showsUserLocation)
@@ -86,30 +94,37 @@ mbgl::Settings_NSUserDefaults *settings = nullptr;
 
 - (void)saveState:(__unused NSNotification *)notification
 {
-    if (self.mapView && settings)
+    if (self.mapView)
     {
-        settings->longitude = self.mapView.centerCoordinate.longitude;
-        settings->latitude = self.mapView.centerCoordinate.latitude;
-        settings->zoom = self.mapView.zoomLevel;
-        settings->bearing = self.mapView.direction;
-        settings->pitch = self.mapView.pitch;
-        settings->debug = self.mapView.isDebugActive;
-        settings->userTrackingMode = self.mapView.userTrackingMode;
-        settings->showsUserLocation = self.mapView.showsUserLocation;
-        settings->save();
+        NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
+        NSData *archivedCamera = [NSKeyedArchiver archivedDataWithRootObject:self.mapView.camera];
+        [defaults setObject:archivedCamera forKey:@"camera"];
+        [defaults setInteger:self.mapView.userTrackingMode forKey:@"userTrackingMode"];
+        [defaults setBool:self.mapView.showsUserLocation forKey:@"showsUserLocation"];
+        [defaults setBool:self.mapView.debugActive forKey:@"debug"];
+        [defaults synchronize];
     }
 }
 
 - (void)restoreState:(__unused NSNotification *)notification
 {
-    if (self.mapView && settings) {
-        settings->load();
-        [self.mapView setCenterCoordinate:CLLocationCoordinate2DMake(settings->latitude, settings->longitude) zoomLevel:settings->zoom animated:NO];
-        self.mapView.direction = settings->bearing;
-        self.mapView.pitch = settings->pitch;
-        self.mapView.userTrackingMode = settings->userTrackingMode;
-        self.mapView.showsUserLocation = settings->showsUserLocation;
-        [self.mapView setDebugActive:settings->debug];
+    if (self.mapView) {
+        NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
+        NSData *archivedCamera = [defaults objectForKey:@"camera"];
+        MGLMapCamera *camera = archivedCamera ? [NSKeyedUnarchiver unarchiveObjectWithData:archivedCamera] : nil;
+        if (camera)
+        {
+            self.mapView.camera = camera;
+        }
+        NSInteger uncheckedTrackingMode = [defaults integerForKey:@"userTrackingMode"];
+        if (uncheckedTrackingMode >= 0 &&
+            (NSUInteger)uncheckedTrackingMode >= MGLUserTrackingModeNone &&
+            (NSUInteger)uncheckedTrackingMode <= MGLUserTrackingModeFollowWithCourse)
+        {
+            self.mapView.userTrackingMode = (MGLUserTrackingMode)uncheckedTrackingMode;
+        }
+        self.mapView.showsUserLocation = [defaults boolForKey:@"showsUserLocation"];
+        self.mapView.debugActive = [defaults boolForKey:@"debug"];
     }
 }
 
@@ -339,12 +354,7 @@ mbgl::Settings_NSUserDefaults *settings = nullptr;
 {
     [[NSNotificationCenter defaultCenter] removeObserver:self];
 
-    if (settings)
-    {
-        [self saveState:nil];
-        delete settings;
-        settings = nullptr;
-    }
+    [self saveState:nil];
 }
 
 #pragma mark - MGLMapViewDelegate

ios/app/mapboxgl-app.gypi

@@ -32,7 +32,6 @@
         './MBXAppDelegate.m',
         './MBXViewController.h',
         './MBXViewController.mm',
-        '../../platform/darwin/settings_nsuserdefaults.mm',
       ],
 
       'xcode_settings': {

platform/ios/MGLMapCamera.mm

@@ -0,0 +1,101 @@
+#import "MGLMapCamera.h"
+
+#include <mbgl/util/projection.hpp>
+
+@implementation MGLMapCamera
+
++ (BOOL)supportsSecureCoding
+{
+    return YES;
+}
+
++ (instancetype)camera
+{
+    return [[self alloc] init];
+}
+
++ (instancetype)cameraLookingAtCenterCoordinate:(CLLocationCoordinate2D)centerCoordinate
+                              fromEyeCoordinate:(CLLocationCoordinate2D)eyeCoordinate
+                                    eyeAltitude:(CLLocationDistance)eyeAltitude
+{
+    mbgl::LatLng centerLatLng = mbgl::LatLng(centerCoordinate.latitude, centerCoordinate.longitude);
+    mbgl::LatLng eyeLatLng = mbgl::LatLng(eyeCoordinate.latitude, eyeCoordinate.longitude);
+    
+    mbgl::ProjectedMeters centerMeters = mbgl::Projection::projectedMetersForLatLng(centerLatLng);
+    mbgl::ProjectedMeters eyeMeters = mbgl::Projection::projectedMetersForLatLng(eyeLatLng);
+    CLLocationDirection heading = std::atan((centerMeters.northing - eyeMeters.northing) /
+                                            (centerMeters.easting - eyeMeters.easting));
+    
+    double groundDistance = std::hypot(centerMeters.northing - eyeMeters.northing,
+                                       centerMeters.easting - eyeMeters.easting);
+    CGFloat pitch = std::atan(eyeAltitude / groundDistance);
+    
+    return [[self alloc] initWithCenterCoordinate:centerCoordinate
+                                         altitude:eyeAltitude
+                                            pitch:pitch
+                                          heading:heading];
+}
+
++ (instancetype)cameraLookingAtCenterCoordinate:(CLLocationCoordinate2D)centerCoordinate
+                                   fromDistance:(CLLocationDistance)distance
+                                          pitch:(CGFloat)pitch
+                                        heading:(CLLocationDirection)heading
+{
+    return [[self alloc] initWithCenterCoordinate:centerCoordinate
+                                         altitude:distance
+                                            pitch:(CGFloat)pitch
+                                          heading:heading];
+}
+
+- (instancetype)initWithCenterCoordinate:(CLLocationCoordinate2D)centerCoordinate
+                                altitude:(CLLocationDistance)altitude
+                                   pitch:(CGFloat)pitch
+                                 heading:(CLLocationDirection)heading
+{
+    if (self = [super init])
+    {
+        _centerCoordinate = centerCoordinate;
+        _altitude = altitude;
+        _pitch = pitch;
+        _heading = heading;
+    }
+    return self;
+}
+
+- (nullable instancetype)initWithCoder:(NSCoder *)coder
+{
+    if (self = [super init])
+    {
+        _centerCoordinate = CLLocationCoordinate2DMake([coder decodeDoubleForKey:@"centerLatitude"],
+                                                       [coder decodeDoubleForKey:@"centerLongitude"]);
+        _altitude = [coder decodeDoubleForKey:@"altitude"];
+        _pitch = [coder decodeDoubleForKey:@"pitch"];
+        _heading = [coder decodeDoubleForKey:@"heading"];
+    }
+    return self;
+}
+
+- (void)encodeWithCoder:(NSCoder *)coder
+{
+    [coder encodeDouble:_centerCoordinate.latitude forKey:@"centerLatitude"];
+    [coder encodeDouble:_centerCoordinate.longitude forKey:@"centerLongitude"];
+    [coder encodeDouble:_altitude forKey:@"altitude"];
+    [coder encodeDouble:_pitch forKey:@"pitch"];
+    [coder encodeDouble:_heading forKey:@"heading"];
+}
+
+- (id)copyWithZone:(nullable NSZone *)zone
+{
+    return [[[self class] allocWithZone:zone] initWithCenterCoordinate:_centerCoordinate
+                                                              altitude:_altitude
+                                                                 pitch:_pitch
+                                                               heading:_heading];
+}
+
+- (NSString *)description
+{
+    return [NSString stringWithFormat:@"<MKMapCamera %p centerCoordinate:%f, %f altitude:%.0fm heading:%.0f° pitch:%.0f°>",
+            self, _centerCoordinate.latitude, _centerCoordinate.longitude, _altitude, _heading, _pitch];
+}
+
+@end

platform/ios/MGLMapView.mm

@@ -48,6 +48,9 @@ NSUInteger const MGLStyleVersion = 8;
 const NSTimeInterval MGLAnimationDuration = 0.3;
 const CGSize MGLAnnotationUpdateViewportOutset = {150, 150};
 const CGFloat MGLMinimumZoom = 3;
+const CGFloat MGLMinimumPitch = 0;
+const CGFloat MGLMaximumPitch = 60;
+const CLLocationDegrees MGLAngularFieldOfView = M_PI / 6.;
 
 NSString *const MGLAnnotationIDKey = @"MGLAnnotationIDKey";
 NSString *const MGLAnnotationSymbolKey = @"MGLAnnotationSymbolKey";
@@ -67,6 +70,18 @@ CLLocationDegrees MGLDegreesFromRadians(CGFloat radians)
     return radians * 180 / M_PI;
 }
 
+mbgl::util::UnitBezier MGLUnitBezierForMediaTimingFunction(CAMediaTimingFunction *function)
+{
+    if ( ! function)
+    {
+        function = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionDefault];
+    }
+    float p1[2], p2[2];
+    [function getControlPointAtIndex:0 values:p1];
+    [function getControlPointAtIndex:1 values:p2];
+    return { p1[0], p1[1], p2[0], p2[1] };
+}
+
 #pragma mark - Private -
 
 @interface MGLMapView () <UIGestureRecognizerDelegate, GLKViewDelegate, CLLocationManagerDelegate, UIActionSheetDelegate>
@@ -368,7 +383,10 @@ std::chrono::steady_clock::duration secondsAsDuration(float duration)
 
     // set initial position
     //
-    _mbglMap->setLatLngZoom(mbgl::LatLng(0, 0), _mbglMap->getMinZoom());
+    mbgl::CameraOptions options;
+    options.center = mbgl::LatLng(0, 0);
+    options.zoom = _mbglMap->getMinZoom();
+    _mbglMap->jumpTo(options);
     _pendingLatitude = NAN;
     _pendingLongitude = NAN;
 
@@ -1347,12 +1365,10 @@ std::chrono::steady_clock::duration secondsAsDuration(float duration)
     else if (twoFingerDrag.state == UIGestureRecognizerStateBegan || twoFingerDrag.state == UIGestureRecognizerStateChanged)
     {
         CGFloat gestureDistance = CGPoint([twoFingerDrag translationInView:twoFingerDrag.view]).y;
-        double currentPitch = _mbglMap->getPitch();
-        double minPitch = 0;
-        double maxPitch = 60.0;
-        double slowdown = 20.0;
+        CGFloat currentPitch = _mbglMap->getPitch();
+        CGFloat slowdown = 20.0;
 
-        double pitchNew = fmax(fmin(currentPitch - (gestureDistance / slowdown), maxPitch), minPitch);
+        CGFloat pitchNew = mbgl::util::clamp(currentPitch - (gestureDistance / slowdown), MGLMinimumPitch, MGLMaximumPitch);
         
         _mbglMap->setPitch(pitchNew);
     }
@@ -1530,7 +1546,7 @@ std::chrono::steady_clock::duration secondsAsDuration(float duration)
 
 + (NS_SET_OF(NSString *) *)keyPathsForValuesAffectingCenterCoordinate
 {
-    return [NSSet setWithObjects:@"latitude", @"longitude", nil];
+    return [NSSet setWithObjects:@"latitude", @"longitude", @"camera", nil];
 }
 
 - (void)setCenterCoordinate:(CLLocationCoordinate2D)coordinate animated:(BOOL)animated preservingTracking:(BOOL)tracking
@@ -1542,13 +1558,7 @@ std::chrono::steady_clock::duration secondsAsDuration(float duration)
 
 - (void)setCenterCoordinate:(CLLocationCoordinate2D)coordinate animated:(BOOL)animated
 {
-    CGFloat duration = (animated ? MGLAnimationDuration : 0);
-
-    _mbglMap->setLatLngZoom(MGLLatLngFromLocationCoordinate2D(coordinate),
-                            fmaxf(_mbglMap->getZoom(), self.currentMinimumZoom),
-                            secondsAsDuration(duration));
-
-    [self notifyMapChange:(animated ? mbgl::MapChangeRegionDidChangeAnimated : mbgl::MapChangeRegionDidChange)];
+    [self setCenterCoordinate:coordinate zoomLevel:self.zoomLevel animated:animated];
 }
 
 - (void)setCenterCoordinate:(CLLocationCoordinate2D)centerCoordinate
@@ -1562,43 +1572,58 @@ std::chrono::steady_clock::duration secondsAsDuration(float duration)
 }
 
 - (void)setCenterCoordinate:(CLLocationCoordinate2D)centerCoordinate zoomLevel:(double)zoomLevel animated:(BOOL)animated
+{
+    [self setCenterCoordinate:centerCoordinate zoomLevel:zoomLevel direction:self.direction animated:animated];
+}
+
+- (void)setCenterCoordinate:(CLLocationCoordinate2D)centerCoordinate zoomLevel:(double)zoomLevel direction:(CLLocationDirection)direction animated:(BOOL)animated
 {
     self.userTrackingMode = MGLUserTrackingModeNone;
 
-    CGFloat duration = (animated ? MGLAnimationDuration : 0);
+    [self _setCenterCoordinate:centerCoordinate zoomLevel:zoomLevel direction:direction animated:animated];
+}
 
-    _mbglMap->setLatLngZoom(MGLLatLngFromLocationCoordinate2D(centerCoordinate), zoomLevel, secondsAsDuration(duration));
+- (void)_setCenterCoordinate:(CLLocationCoordinate2D)centerCoordinate zoomLevel:(double)zoomLevel direction:(CLLocationDirection)direction animated:(BOOL)animated
+{
+    mbgl::CameraOptions options;
+    options.center = MGLLatLngFromLocationCoordinate2D(centerCoordinate);
+    options.zoom = fmaxf(zoomLevel, self.currentMinimumZoom);
+    if (direction >= 0)
+    {
+        options.angle = MGLRadiansFromDegrees(-direction);
+    }
+    if (animated)
+    {
+        options.duration = secondsAsDuration(MGLAnimationDuration);
+        options.easing = MGLUnitBezierForMediaTimingFunction(nil);
+    }
+    _mbglMap->easeTo(options);
 
     [self unrotateIfNeededAnimated:animated];
 
     [self notifyMapChange:(animated ? mbgl::MapChangeRegionDidChangeAnimated : mbgl::MapChangeRegionDidChange)];
 }
 
++ (NS_SET_OF(NSString *) *)keyPathsForValuesAffectingZoomLevel
+{
+    return [NSSet setWithObject:@"camera"];
+}
+
 - (double)zoomLevel
 {
     return _mbglMap->getZoom();
 }
 
-- (void)setZoomLevel:(double)zoomLevel animated:(BOOL)animated
-{
-    self.userTrackingMode = MGLUserTrackingModeNone;
-
-    CGFloat duration = (animated ? MGLAnimationDuration : 0);
-
-    _mbglMap->setLatLngZoom(_mbglMap->getLatLng(),
-                           fmaxf(zoomLevel, self.currentMinimumZoom),
-                           secondsAsDuration(duration));
-
-    [self unrotateIfNeededAnimated:animated];
-
-    [self notifyMapChange:(animated ? mbgl::MapChangeRegionDidChangeAnimated : mbgl::MapChangeRegionDidChange)];
-}
-
 - (void)setZoomLevel:(double)zoomLevel
 {
     [self setZoomLevel:zoomLevel animated:NO];
 }
 
+- (void)setZoomLevel:(double)zoomLevel animated:(BOOL)animated
+{
+    [self setCenterCoordinate:self.centerCoordinate zoomLevel:zoomLevel animated:animated];
+}
+
 MGLCoordinateBounds MGLCoordinateBoundsFromLatLngBounds(mbgl::LatLngBounds latLngBounds)
 {
     return MGLCoordinateBoundsMake(MGLLocationCoordinate2DFromLatLng(latLngBounds.sw),
@@ -1639,11 +1664,34 @@ mbgl::LatLngBounds MGLLatLngBoundsFromCoordinateBounds(MGLCoordinateBounds coord
                        animated:animated];
 }
 
+- (void)setVisibleCoordinateBounds:(MGLCoordinateBounds)bounds edgePadding:(UIEdgeInsets)insets direction:(CLLocationDirection)direction animated:(BOOL)animated
+{
+    CLLocationCoordinate2D coordinates[] = {
+        {bounds.ne.latitude, bounds.sw.longitude},
+        bounds.sw,
+        {bounds.sw.latitude, bounds.ne.longitude},
+        bounds.ne,
+    };
+    [self setVisibleCoordinates:coordinates
+                          count:sizeof(coordinates) / sizeof(coordinates[0])
+                    edgePadding:insets
+                      direction:direction
+                       animated:animated];
+}
+
 - (void)setVisibleCoordinates:(CLLocationCoordinate2D *)coordinates count:(NSUInteger)count edgePadding:(UIEdgeInsets)insets animated:(BOOL)animated
+{
+    [self setVisibleCoordinates:coordinates count:count edgePadding:insets direction:self.direction animated:animated];
+}
+
+- (void)setVisibleCoordinates:(CLLocationCoordinate2D *)coordinates count:(NSUInteger)count edgePadding:(UIEdgeInsets)insets direction:(CLLocationDirection)direction animated:(BOOL)animated
+{
+    [self setVisibleCoordinates:coordinates count:count edgePadding:insets direction:direction duration:animated ? MGLAnimationDuration : 0 animationTimingFunction:nil];
+}
+
+- (void)setVisibleCoordinates:(CLLocationCoordinate2D *)coordinates count:(NSUInteger)count edgePadding:(UIEdgeInsets)insets direction:(CLLocationDirection)direction duration:(NSTimeInterval)duration animationTimingFunction:(CAMediaTimingFunction *)function
 {
     // NOTE: does not disrupt tracking mode
-    CGFloat duration = animated ? MGLAnimationDuration : 0;
-    
     [self willChangeValueForKey:@"visibleCoordinateBounds"];
     mbgl::EdgeInsets mbglInsets = {insets.top, insets.left, insets.bottom, insets.right};
     mbgl::AnnotationSegment segment;
@@ -1652,12 +1700,27 @@ mbgl::LatLngBounds MGLLatLngBoundsFromCoordinateBounds(MGLCoordinateBounds coord
     {
         segment.push_back({coordinates[i].latitude, coordinates[i].longitude});
     }
-    _mbglMap->fitBounds(segment, mbglInsets, secondsAsDuration(duration));
+    mbgl::CameraOptions options = _mbglMap->cameraForLatLngs(segment, mbglInsets);
+    if (direction >= 0)
+    {
+        options.angle = MGLRadiansFromDegrees(-direction);
+    }
+    if (duration > 0)
+    {
+        options.duration = secondsAsDuration(duration);
+        options.easing = MGLUnitBezierForMediaTimingFunction(function);
+    }
+    _mbglMap->easeTo(options);
     [self didChangeValueForKey:@"visibleCoordinateBounds"];
     
-    [self unrotateIfNeededAnimated:animated];
+    [self unrotateIfNeededAnimated:duration > 0];
     
-    [self notifyMapChange:(animated ? mbgl::MapChangeRegionDidChangeAnimated : mbgl::MapChangeRegionDidChange)];
+    [self notifyMapChange:(duration > 0 ? mbgl::MapChangeRegionDidChangeAnimated : mbgl::MapChangeRegionDidChange)];
+}
+
++ (NS_SET_OF(NSString *) *)keyPathsForValuesAffectingDirection
+{
+    return [NSSet setWithObject:@"camera"];
 }
 
 - (CLLocationDirection)direction
@@ -1683,23 +1746,139 @@ mbgl::LatLngBounds MGLLatLngBoundsFromCoordinateBounds(MGLCoordinateBounds coord
     [self setDirection:direction animated:NO];
 }
 
-- (double)pitch
++ (NS_SET_OF(NSString *) *)keyPathsForValuesAffectingPitch
 {
-    return _mbglMap->getPitch();
+    return [NSSet setWithObject:@"camera"];
 }
 
-- (void)setPitch:(double)pitch
++ (NS_SET_OF(NSString *) *)keyPathsForValuesAffectingCamera
 {
-    // constrain pitch to between 0º and 60º
-    //
-    _mbglMap->setPitch(fmax(fmin(pitch, 60), 0));
+    return [NSSet setWithObjects:@"longitude", @"latitude", @"centerCoordinate", @"zoomLevel", @"direction", nil];
+}
+
+- (MGLMapCamera *)camera
+{
+    CGRect frame = self.frame;
+    CGPoint edgePoint;
+    // Constrain by the shorter of the two axes.
+    if (frame.size.width > frame.size.height) // landscape
+    {
+        edgePoint = CGPointMake(0, frame.size.height / 2.);
+    }
+    else // portrait
+    {
+        edgePoint = CGPointMake(frame.size.width / 2., 0);
+    }
+    CLLocationCoordinate2D edgeCoordinate = [self convertPoint:edgePoint toCoordinateFromView:self];
+    mbgl::ProjectedMeters edgeMeters = _mbglMap->projectedMetersForLatLng(MGLLatLngFromLocationCoordinate2D(edgeCoordinate));
     
-    //[self notifyMapChange:(mbgl::MapChangeRegionDidChange)];
+    // Because we constrain the zoom level vertically in portrait orientation,
+    // the visible medial span is affected by pitch: the distance from the
+    // center point to the near edge is less than than distance from the center
+    // point to the far edge. Average the two distances.
+    mbgl::ProjectedMeters nearEdgeMeters;
+    if (frame.size.width > frame.size.height)
+    {
+        nearEdgeMeters = edgeMeters;
+    }
+    else
+    {
+        CGPoint nearEdgePoint = CGPointMake(frame.size.width / 2., frame.size.height);
+        CLLocationCoordinate2D nearEdgeCoordinate = [self convertPoint:nearEdgePoint toCoordinateFromView:self];
+        nearEdgeMeters = _mbglMap->projectedMetersForLatLng(MGLLatLngFromLocationCoordinate2D(nearEdgeCoordinate));
+    }
+    
+    // The opposite side is the distance between the center and one edge.
+    CLLocationCoordinate2D centerCoordinate = self.centerCoordinate;
+    mbgl::ProjectedMeters centerMeters = _mbglMap->projectedMetersForLatLng(MGLLatLngFromLocationCoordinate2D(centerCoordinate));
+    CLLocationDistance centerToEdge = std::hypot(centerMeters.easting - edgeMeters.easting,
+                                                 centerMeters.northing - edgeMeters.northing);
+    CLLocationDistance centerToNearEdge = std::hypot(centerMeters.easting - nearEdgeMeters.easting,
+                                                     centerMeters.northing - nearEdgeMeters.northing);
+    CLLocationDistance altitude = (centerToEdge + centerToNearEdge) / 2 / std::tan(MGLAngularFieldOfView / 2.);
+    
+    CGFloat pitch = _mbglMap->getPitch();
+    
+    return [MGLMapCamera cameraLookingAtCenterCoordinate:centerCoordinate
+                                            fromDistance:altitude
+                                                   pitch:pitch
+                                                 heading:self.direction];
 }
 
-- (void)resetPitch
+- (void)setCamera:(MGLMapCamera *)camera
 {
-    [self setPitch:0];
+    [self setCamera:camera animated:NO];
+}
+
+- (void)setCamera:(MGLMapCamera *)camera animated:(BOOL)animated
+{
+    [self setCamera:camera withDuration:animated ? MGLAnimationDuration : 0 animationTimingFunction:nil];
+}
+
+- (void)setCamera:(MGLMapCamera *)camera withDuration:(NSTimeInterval)duration animationTimingFunction:(CAMediaTimingFunction *)function
+{
+    // The opposite side is the distance between the center and one edge.
+    mbgl::LatLng centerLatLng = MGLLatLngFromLocationCoordinate2D(camera.centerCoordinate);
+    mbgl::ProjectedMeters centerMeters = _mbglMap->projectedMetersForLatLng(centerLatLng);
+    CLLocationDistance centerToEdge = camera.altitude * std::tan(MGLAngularFieldOfView / 2.);
+    
+    double angle = -1;
+    if (camera.heading >= 0)
+    {
+        angle = MGLRadiansFromDegrees(mbgl::util::wrap(-camera.heading, 0., 360.));
+    }
+    double pitch = -1;
+    if (camera.pitch >= 0)
+    {
+        pitch = MGLRadiansFromDegrees(mbgl::util::clamp(camera.pitch, MGLMinimumPitch, MGLMaximumPitch));
+    }
+    
+    // Make a visible bounds that extends in the constrained direction (the
+    // shorter of the two axes).
+    CGRect frame = self.frame;
+    mbgl::LatLng sw, ne;
+    if (frame.size.width > frame.size.height) // landscape
+    {
+        sw = _mbglMap->latLngForProjectedMeters({
+            centerMeters.northing - centerToEdge * std::sin(angle),
+            centerMeters.easting - centerToEdge * std::cos(angle),
+        });
+        ne = _mbglMap->latLngForProjectedMeters({
+            centerMeters.northing + centerToEdge * std::sin(angle),
+            centerMeters.easting + centerToEdge * std::cos(angle),
+        });
+    }
+    else // portrait
+    {
+        sw = _mbglMap->latLngForProjectedMeters({
+            centerMeters.northing - centerToEdge * std::cos(angle) + centerToEdge * std::cos(angle) * std::sin(pitch) / 2,
+            centerMeters.easting - centerToEdge * std::sin(angle) + centerToEdge * std::sin(angle) * std::sin(pitch) / 2,
+        });
+        ne = _mbglMap->latLngForProjectedMeters({
+            centerMeters.northing + centerToEdge * std::cos(angle) - centerToEdge * std::cos(angle) * std::sin(pitch) / 2,
+            centerMeters.easting + centerToEdge * std::sin(angle) - centerToEdge * std::sin(angle) * std::sin(pitch) / 2,
+        });
+    }
+    
+    // Fit the viewport to the bounds. Correct the center in case pitch should
+    // cause the visual center to lie above the screen center.
+    mbgl::CameraOptions options = _mbglMap->cameraForLatLngs({ sw, ne }, {});
+    options.center = centerLatLng;
+    
+    if (angle >= 0)
+    {
+        options.angle = angle;
+    }
+    if (pitch >= 0)
+    {
+        options.pitch = pitch;
+    }
+    if (duration > 0)
+    {
+        options.duration = secondsAsDuration(duration);
+        options.easing = MGLUnitBezierForMediaTimingFunction(function);
+    }
+    _mbglMap->easeTo(options);
 }
 
 - (CLLocationCoordinate2D)convertPoint:(CGPoint)point toCoordinateFromView:(nullable UIView *)view
@@ -2482,6 +2661,12 @@ CLLocationCoordinate2D MGLLocationCoordinate2DFromLatLng(mbgl::LatLng latLng)
             [self.delegate mapView:self didUpdateUserLocation:self.userLocation];
         }
     }
+    
+    CLLocationDirection course = self.userLocation.location.course;
+    if (course < 0 || self.userTrackingMode != MGLUserTrackingModeFollowWithCourse)
+    {
+        course = -1;
+    }
 
     if (self.userTrackingMode != MGLUserTrackingModeNone)
     {
@@ -2496,7 +2681,7 @@ CLLocationCoordinate2D MGLLocationCoordinate2DFromLatLng(mbgl::LatLng latLng)
             {
                 // at sufficient detail, just re-center the map; don't zoom
                 //
-                [self setCenterCoordinate:self.userLocation.location.coordinate animated:YES preservingTracking:YES];
+                [self _setCenterCoordinate:self.userLocation.location.coordinate zoomLevel:self.zoomLevel direction:course animated:YES];
             }
             else
             {
@@ -2526,17 +2711,11 @@ CLLocationCoordinate2D MGLLocationCoordinate2DFromLatLng(mbgl::LatLng latLng)
                     desiredSouthWest.longitude != actualSouthWest.longitude)
                 {
                     // assumes we won't disrupt tracking mode
-                    [self setVisibleCoordinateBounds:MGLCoordinateBoundsMake(desiredSouthWest, desiredNorthEast) animated:YES];
+                    [self setVisibleCoordinateBounds:MGLCoordinateBoundsMake(desiredSouthWest, desiredNorthEast) edgePadding:UIEdgeInsetsZero direction:course animated:YES];
                 }
             }
         }
     }
-
-    CLLocationDirection course = self.userLocation.location.course;
-    if (course >= 0 && self.userTrackingMode == MGLUserTrackingModeFollowWithCourse)
-    {
-        _mbglMap->setBearing(course);
-    }
     
     self.userLocationAnnotationView.haloLayer.hidden = ! CLLocationCoordinate2DIsValid(self.userLocation.coordinate) ||
         newLocation.horizontalAccuracy > 10;
@@ -3088,7 +3267,7 @@ class MBGLView : public mbgl::View
 
 + (NS_SET_OF(NSString *) *)keyPathsForValuesAffectingLatitude
 {
-    return [NSSet setWithObject:@"centerCoordinate"];
+    return [NSSet setWithObjects:@"centerCoordinate", @"camera", nil];
 }
 
 - (double)latitude
@@ -3114,7 +3293,7 @@ class MBGLView : public mbgl::View
 
 + (NS_SET_OF(NSString *) *)keyPathsForValuesAffectingLongitude
 {
-    return [NSSet setWithObject:@"centerCoordinate"];
+    return [NSSet setWithObjects:@"centerCoordinate", @"camera", nil];
 }
 
 - (double)longitude

src/mbgl/map/camera.cpp

@@ -0,0 +1 @@
+#include <mbgl/map/camera.hpp>

src/mbgl/map/map.cpp

@@ -9,6 +9,7 @@
 
 #include <mbgl/util/projection.hpp>
 #include <mbgl/util/thread.hpp>
+#include <mbgl/util/math.hpp>
 
 namespace mbgl {
 
@@ -114,6 +115,18 @@ void Map::setGestureInProgress(bool inProgress) {
     update(Update::Repaint);
 }
 
+#pragma mark -
+
+void Map::jumpTo(CameraOptions options) {
+    transform->jumpTo(options);
+    update(Update::Repaint);
+}
+
+void Map::easeTo(CameraOptions options) {
+    transform->easeTo(options);
+    update(options.zoom ? Update::Zoom : Update::Repaint);
+}
+
 #pragma mark - Position
 
 void Map::moveBy(double dx, double dy, const Duration& duration) {
@@ -131,9 +144,11 @@ LatLng Map::getLatLng() const {
 }
 
 void Map::resetPosition() {
-    transform->setAngle(0);
-    transform->setLatLng(LatLng(0, 0));
-    transform->setZoom(0);
+    CameraOptions options;
+    options.angle = 0;
+    options.center = LatLng(0, 0);
+    options.zoom = 0;
+    transform->jumpTo(options);
     update(Update::Zoom);
 }
 
@@ -168,25 +183,26 @@ void Map::setLatLngZoom(LatLng latLng, double zoom, const Duration& duration) {
     update(Update::Zoom);
 }
 
-void Map::fitBounds(LatLngBounds bounds, EdgeInsets padding, const Duration& duration) {
+CameraOptions Map::cameraForLatLngBounds(LatLngBounds bounds, EdgeInsets padding) {
     AnnotationSegment segment = {
         {bounds.ne.latitude, bounds.sw.longitude},
         bounds.sw,
         {bounds.sw.latitude, bounds.ne.longitude},
         bounds.ne,
     };
-    fitBounds(segment, padding, duration);
+    return cameraForLatLngs(segment, padding);
 }
 
-void Map::fitBounds(AnnotationSegment segment, EdgeInsets padding, const Duration& duration) {
-    if (segment.empty()) {
-        return;
+CameraOptions Map::cameraForLatLngs(std::vector<LatLng> latLngs, EdgeInsets padding) {
+    CameraOptions options;
+    if (latLngs.empty()) {
+        return options;
     }
 
     // Calculate the bounds of the possibly rotated shape with respect to the viewport.
     vec2<> nePixel = {-INFINITY, -INFINITY};
     vec2<> swPixel = {INFINITY, INFINITY};
-    for (LatLng latLng : segment) {
+    for (LatLng latLng : latLngs) {
         vec2<> pixel = pixelForLatLng(latLng);
         swPixel.x = std::min(swPixel.x, pixel.x);
         nePixel.x = std::max(nePixel.x, pixel.x);
@@ -214,7 +230,9 @@ void Map::fitBounds(AnnotationSegment segment, EdgeInsets padding, const Duratio
     vec2<> centerPixel = (paddedNEPixel + paddedSWPixel) * 0.5;
     LatLng centerLatLng = latLngForPixel(centerPixel);
 
-    setLatLngZoom(centerLatLng, zoom, duration);
+    options.center = centerLatLng;
+    options.zoom = zoom;
+    return options;
 }
 
 void Map::resetZoom() {
@@ -270,8 +288,8 @@ void Map::resetNorth() {
 
 #pragma mark - Pitch
 
-void Map::setPitch(double pitch) {
-    transform->setPitch(std::min(pitch, 60.0) * M_PI / 180);
+void Map::setPitch(double pitch, const Duration& duration) {
+    transform->setPitch(util::clamp(pitch, 0., 60.) * M_PI / 180, duration);
     update(Update::Repaint);
 }
 

src/mbgl/map/transform.cpp

@@ -1,3 +1,4 @@
+#include <mbgl/map/camera.hpp>
 #include <mbgl/map/transform.hpp>
 #include <mbgl/map/view.hpp>
 #include <mbgl/util/constants.hpp>
@@ -53,6 +54,38 @@ bool Transform::resize(const std::array<uint16_t, 2> size) {
 
 #pragma mark - Position
 
+void Transform::jumpTo(const CameraOptions options) {
+    CameraOptions jumpOptions = options;
+    jumpOptions.duration.reset();
+    easeTo(jumpOptions);
+}
+
+void Transform::easeTo(CameraOptions options) {
+    LatLng latLng = options.center ? *options.center : getLatLng();
+    double zoom = options.zoom ? *options.zoom : getZoom();
+    double angle = options.angle ? *options.angle : getAngle();
+    if (std::isnan(latLng.latitude) || std::isnan(latLng.longitude) || std::isnan(zoom)) {
+        return;
+    }
+    
+    double new_scale = std::pow(2.0, zoom);
+    
+    const double s = new_scale * util::tileSize;
+    state.Bc = s / 360;
+    state.Cc = s / util::M2PI;
+    
+    const double m = 1 - 1e-15;
+    const double f = std::fmin(std::fmax(std::sin(util::DEG2RAD * latLng.latitude), -m), m);
+    
+    double xn = -latLng.longitude * state.Bc;
+    double yn = 0.5 * state.Cc * std::log((1 + f) / (1 - f));
+    
+    options.center.reset();
+    options.zoom.reset();
+    options.angle.reset();
+    _easeTo(options, new_scale, angle, xn, yn);
+}
+
 void Transform::moveBy(const double dx, const double dy, const Duration& duration) {
     if (std::isnan(dx) || std::isnan(dy)) {
         return;
@@ -62,71 +95,30 @@ void Transform::moveBy(const double dx, const double dy, const Duration& duratio
 }
 
 void Transform::_moveBy(const double dx, const double dy, const Duration& duration) {
+    
     double x = state.x + std::cos(state.angle) * dx + std::sin( state.angle) * dy;
     double y = state.y + std::cos(state.angle) * dy + std::sin(-state.angle) * dx;
 
     state.constrain(state.scale, y);
-
-    if (duration == Duration::zero()) {
-        view.notifyMapChange(MapChangeRegionWillChange);
-
-        state.x = x;
-        state.y = y;
-
-        view.notifyMapChange(MapChangeRegionDidChange);
-    } else {
-        view.notifyMapChange(MapChangeRegionWillChangeAnimated);
-
-        const double startX = state.x;
-        const double startY = state.y;
-        state.panning = true;
-
-        startTransition(
-            [=](double t) {
-                state.x = util::interpolate(startX, x, t);
-                state.y = util::interpolate(startY, y, t);
-                view.notifyMapChange(MapChangeRegionIsChanging);
-                return Update::Repaint;
-            },
-            [=] {
-                state.panning = false;
-                view.notifyMapChange(MapChangeRegionDidChangeAnimated);
-            }, duration);
-    }
+    
+    CameraOptions options;
+    options.duration = duration;
+    _easeTo(options, state.scale, state.angle, x, y);
 }
 
 void Transform::setLatLng(const LatLng latLng, const Duration& duration) {
-    if (std::isnan(latLng.latitude) || std::isnan(latLng.longitude)) {
-        return;
-    }
-
-    const double m = 1 - 1e-15;
-    const double f = ::fmin(::fmax(std::sin(util::DEG2RAD * latLng.latitude), -m), m);
-
-    double xn = -latLng.longitude * state.Bc;
-    double yn = 0.5 * state.Cc * std::log((1 + f) / (1 - f));
-
-    _setScaleXY(state.scale, xn, yn, duration);
+    CameraOptions options;
+    options.center = latLng;
+    options.duration = duration;
+    easeTo(options);
 }
 
 void Transform::setLatLngZoom(const LatLng latLng, const double zoom, const Duration& duration) {
-    if (std::isnan(latLng.latitude) || std::isnan(latLng.longitude) || std::isnan(zoom)) {
-        return;
-    }
-
-    double new_scale = std::pow(2.0, zoom);
-
-    const double s = new_scale * util::tileSize;
-    state.Bc = s / 360;
-    state.Cc = s / util::M2PI;
-
-    const double m = 1 - 1e-15;
-    const double f = ::fmin(::fmax(std::sin(util::DEG2RAD * latLng.latitude), -m), m);
-
-    double xn = -latLng.longitude * state.Bc;
-    double yn = 0.5 * state.Cc * std::log((1 + f) / (1 - f));
-
-    _setScaleXY(new_scale, xn, yn, duration);
+    CameraOptions options;
+    options.center = latLng;
+    options.zoom = zoom;
+    options.duration = duration;
+    easeTo(options);
 }
 
 
@@ -206,13 +198,27 @@ void Transform::_setScale(double new_scale, double cx, double cy, const Duration
 
 void Transform::_setScaleXY(const double new_scale, const double xn, const double yn,
                             const Duration& duration) {
+    CameraOptions options;
+    options.duration = duration;
+    _easeTo(options, new_scale, state.angle, xn, yn);
+}
+
+void Transform::_easeTo(CameraOptions options, const double new_scale, const double new_angle, const double xn, const double yn) {
+    Update update = state.scale == new_scale ? Update::Repaint : Update::Zoom;
     double scale = new_scale;
     double x = xn;
     double y = yn;
 
     state.constrain(scale, y);
+    
+    double angle = _normalizeAngle(new_angle, state.angle);
+    state.angle = _normalizeAngle(state.angle, angle);
+    double pitch = options.pitch ? *options.pitch : state.pitch;
 
-    if (duration == Duration::zero()) {
+    if (!options.duration) {
+        options.duration = Duration::zero();
+    }
+    if (!options.duration || *options.duration == Duration::zero()) {
         view.notifyMapChange(MapChangeRegionWillChange);
 
         state.scale = scale;
@@ -221,18 +227,28 @@ void Transform::_setScaleXY(const double new_scale, const double xn, const doubl
         const double s = state.scale * util::tileSize;
         state.Bc = s / 360;
         state.Cc = s / util::M2PI;
+        
+        state.angle = angle;
+        state.pitch = pitch;
 
         view.notifyMapChange(MapChangeRegionDidChange);
     } else {
         view.notifyMapChange(MapChangeRegionWillChangeAnimated);
 
         const double startS = state.scale;
+        const double startA = state.angle;
+        const double startP = state.pitch;
         const double startX = state.x;
         const double startY = state.y;
         state.panning = true;
         state.scaling = true;
+        state.rotating = true;
 
         startTransition(
+            [=](double t) {
+                util::UnitBezier ease = options.easing ? *options.easing : util::UnitBezier(0, 0, 0.25, 1);
+                return ease.solve(t, 0.001);
+            },
             [=](double t) {
                 state.scale = util::interpolate(startS, scale, t);
                 state.x = util::interpolate(startX, x, t);
@@ -240,14 +256,17 @@ void Transform::_setScaleXY(const double new_scale, const double xn, const doubl
                 const double s = state.scale * util::tileSize;
                 state.Bc = s / 360;
                 state.Cc = s / util::M2PI;
+                state.angle = util::wrap(util::interpolate(startA, angle, t), -M_PI, M_PI);
+                state.pitch = util::interpolate(startP, pitch, t);
                 view.notifyMapChange(MapChangeRegionIsChanging);
-                return Update::Zoom;
+                return update;
             },
             [=] {
                 state.panning = false;
                 state.scaling = false;
+                state.rotating = false;
                 view.notifyMapChange(MapChangeRegionDidChangeAnimated);
-            }, duration);
+            }, *options.duration);
     }
 }
 
@@ -307,7 +326,7 @@ void Transform::setAngle(const double new_angle, const double cx, const double c
         _moveBy(dx, dy, Duration::zero());
     }
 
-    _setAngle(new_angle, Duration::zero());
+    _setAngle(new_angle);
 
     if (cx >= 0 && cy >= 0) {
         _moveBy(-dx, -dy, Duration::zero());
@@ -315,32 +334,10 @@ void Transform::setAngle(const double new_angle, const double cx, const double c
 }
 
 void Transform::_setAngle(double new_angle, const Duration& duration) {
-    double angle = _normalizeAngle(new_angle, state.angle);
-    state.angle = _normalizeAngle(state.angle, angle);
-
-    if (duration == Duration::zero()) {
-        view.notifyMapChange(MapChangeRegionWillChange);
-
-        state.angle = angle;
-
-        view.notifyMapChange(MapChangeRegionDidChange);
-    } else {
-        view.notifyMapChange(MapChangeRegionWillChangeAnimated);
-
-        const double startA = state.angle;
-        state.rotating = true;
-
-        startTransition(
-            [=](double t) {
-                state.angle = util::wrap(util::interpolate(startA, angle, t), -M_PI, M_PI);
-                view.notifyMapChange(MapChangeRegionIsChanging);
-                return Update::Repaint;
-            },
-            [=] {
-                state.rotating = false;
-                view.notifyMapChange(MapChangeRegionDidChangeAnimated);
-            }, duration);
-    }
+    CameraOptions options;
+    options.angle = new_angle;
+    options.duration = duration;
+    easeTo(options);
 }
 
 double Transform::getAngle() const {
@@ -349,8 +346,11 @@ double Transform::getAngle() const {
 
 #pragma mark - Pitch
 
-void Transform::setPitch(double pitch) {
-    state.pitch = pitch;
+void Transform::setPitch(double pitch, const Duration& duration) {
+    CameraOptions options;
+    options.pitch = pitch;
+    options.duration = duration;
+    easeTo(options);
 }
 
 double Transform::getPitch() const {
@@ -359,7 +359,8 @@ double Transform::getPitch() const {
 
 #pragma mark - Transition
 
-void Transform::startTransition(std::function<Update(double)> frame,
+void Transform::startTransition(std::function<double(double)> easing,
+                                std::function<Update(double)> frame,
                                 std::function<void()> finish,
                                 const Duration& duration) {
     if (transitionFinishFn) {
@@ -369,7 +370,7 @@ void Transform::startTransition(std::function<Update(double)> frame,
     transitionStart = Clock::now();
     transitionDuration = duration;
 
-    transitionFrameFn = [frame, this](const TimePoint now) {
+    transitionFrameFn = [easing, frame, this](const TimePoint now) {
         float t = std::chrono::duration<float>(now - transitionStart) / transitionDuration;
         if (t >= 1.0) {
             Update result = frame(1.0);
@@ -378,8 +379,7 @@ void Transform::startTransition(std::function<Update(double)> frame,
             transitionFinishFn = nullptr;
             return result;
         } else {
-            util::UnitBezier ease(0, 0, 0.25, 1);
-            return frame(ease.solve(t, 0.001));
+            return frame(easing(t));
         }
     };
 

src/mbgl/map/transform.hpp

@@ -2,6 +2,7 @@
 #define MBGL_MAP_TRANSFORM
 
 #include <mbgl/map/transform_state.hpp>
+#include <mbgl/map/camera.hpp>
 #include <mbgl/util/chrono.hpp>
 #include <mbgl/map/update.hpp>
 #include <mbgl/util/geo.hpp>
@@ -22,6 +23,9 @@ public:
     // Map view
     bool resize(std::array<uint16_t, 2> size);
 
+    void jumpTo(const CameraOptions options);
+    void easeTo(const CameraOptions options);
+
     // Position
     void moveBy(double dx, double dy, const Duration& = Duration::zero());
     void setLatLng(LatLng latLng, const Duration& = Duration::zero());
@@ -42,7 +46,7 @@ public:
     double getAngle() const;
 
     // Pitch
-    void setPitch(double pitch);
+    void setPitch(double pitch, const Duration& = Duration::zero());
     double getPitch() const;
 
     // Transitions
@@ -60,13 +64,16 @@ private:
     void _moveBy(double dx, double dy, const Duration& = Duration::zero());
     void _setScale(double scale, double cx, double cy, const Duration& = Duration::zero());
     void _setScaleXY(double new_scale, double xn, double yn, const Duration& = Duration::zero());
+    void _easeTo(CameraOptions options, const double new_scale, const double new_angle,
+                 const double xn, const double yn);
     void _setAngle(double angle, const Duration& = Duration::zero());
 
     View &view;
 
     TransformState state;
 
-    void startTransition(std::function<Update(double)> frame,
+    void startTransition(std::function<double(double)> easing,
+                         std::function<Update(double)> frame,
                          std::function<void()> finish,
                          const Duration& duration);