[ios, macos] Fixed camera initialization with eye coordinate

Rewrote the code that calculates the heading and pitch of the camera when given an eye coordinate.
mapbox · Sep 27, 2018 · f42bbd4 · f42bbd4
1 parent 8577a32
commit f42bbd4
Show file tree

Hide file tree

Showing 4 changed files with 54 additions and 5 deletions.
diff --git a/platform/darwin/src/MGLMapCamera.mm b/platform/darwin/src/MGLMapCamera.mm
@@ -1,7 +1,10 @@
 #import "MGLMapCamera.h"
 #import "MGLGeometry_Private.h"
 
+#import <CoreLocation/CoreLocation.h>
+
 #include <mbgl/util/projection.hpp>
+#include <mbgl/math/wrap.hpp>
 
 BOOL MGLEqualFloatWithAccuracy(CGFloat left, CGFloat right, CGFloat accuracy)
 {
@@ -32,12 +35,17 @@ + (instancetype)cameraLookingAtCenterCoordinate:(CLLocationCoordinate2D)centerCo
 
         mbgl::ProjectedMeters centerMeters = mbgl::Projection::projectedMetersForLatLng(centerLatLng);
         mbgl::ProjectedMeters eyeMeters = mbgl::Projection::projectedMetersForLatLng(eyeLatLng);
-        heading = std::atan((centerMeters.northing() - eyeMeters.northing()) /
-                            (centerMeters.easting() - eyeMeters.easting()));
+        CGFloat radianHeading = atan2(centerMeters.easting() - eyeMeters.easting(),
+                                      centerMeters.northing() - eyeMeters.northing());
+        heading = mbgl::util::wrap(MGLDegreesFromRadians(radianHeading), 0.0, 360.0);
 
-        double groundDistance = std::hypot(centerMeters.northing() - eyeMeters.northing(),
-                                           centerMeters.easting() - eyeMeters.easting());
-        pitch = std::atan(eyeAltitude / groundDistance);
+        CLLocation *centerLocation = [[CLLocation alloc] initWithLatitude:centerCoordinate.latitude
+                                                                longitude:centerCoordinate.longitude];
+        CLLocation *eyeLocation = [[CLLocation alloc] initWithLatitude:eyeCoordinate.latitude
+                                                             longitude:eyeCoordinate.longitude];
+        CLLocationDistance groundDistance = [eyeLocation distanceFromLocation:centerLocation];
+        CGFloat radianPitch = atan2(eyeAltitude, groundDistance);
+        pitch = mbgl::util::wrap(90 - MGLDegreesFromRadians(radianPitch), 0.0, 360.0);
     }
 
     return [[self alloc] initWithCenterCoordinate:centerCoordinate

diff --git a/platform/darwin/test/MGLMapCameraTests.m b/platform/darwin/test/MGLMapCameraTests.m
@@ -9,6 +9,45 @@ @interface MGLMapCameraTests : XCTestCase
 
 @implementation MGLMapCameraTests
 
+- (void)testEyeCoordinateInitialization {
+    CLLocationCoordinate2D fountainSquare = CLLocationCoordinate2DMake(39.10152215, -84.5124439696089);
+    CLLocationCoordinate2D unionTerminal = CLLocationCoordinate2DMake(39.10980955, -84.5352778794236);
+
+    MGLMapCamera *camera = [MGLMapCamera cameraLookingAtCenterCoordinate:fountainSquare
+                                                       fromEyeCoordinate:fountainSquare
+                                                             eyeAltitude:1000];
+    MKMapCamera *mkCamera = [MKMapCamera cameraLookingAtCenterCoordinate:fountainSquare
+                                                       fromEyeCoordinate:fountainSquare
+                                                             eyeAltitude:1000];
+    XCTAssertEqual(camera.centerCoordinate.latitude, fountainSquare.latitude);
+    XCTAssertEqual(camera.centerCoordinate.longitude, fountainSquare.longitude);
+    XCTAssertEqual(camera.centerCoordinate.latitude, mkCamera.centerCoordinate.latitude);
+    XCTAssertEqual(camera.centerCoordinate.longitude, mkCamera.centerCoordinate.longitude);
+    XCTAssertEqual(camera.altitude, 1000, @"Eye altitude should be equivalent to altitude in untilted camera.");
+    XCTAssertEqual(camera.altitude, mkCamera.altitude, @"Eye altitude in untilted camera should match MapKit.");
+    XCTAssertEqual(camera.pitch, 0, @"Camera directly over center coordinate should be untilted.");
+    XCTAssertEqual(camera.pitch, mkCamera.pitch, @"Camera directly over center coordinate should have same pitch as MapKit.");
+    XCTAssertEqual(camera.heading, 0, @"Camera directly over center coordinate should be unrotated.");
+    XCTAssertEqual(camera.heading, mkCamera.heading, @"Camera directly over center coordinate should have same heading as MapKit.");
+
+    camera = [MGLMapCamera cameraLookingAtCenterCoordinate:fountainSquare
+                                         fromEyeCoordinate:unionTerminal
+                                               eyeAltitude:1000];
+    mkCamera = [MKMapCamera cameraLookingAtCenterCoordinate:fountainSquare
+                                          fromEyeCoordinate:unionTerminal
+                                                eyeAltitude:1000];
+    XCTAssertEqual(camera.centerCoordinate.latitude, fountainSquare.latitude);
+    XCTAssertEqual(camera.centerCoordinate.longitude, fountainSquare.longitude);
+    XCTAssertEqual(camera.centerCoordinate.latitude, mkCamera.centerCoordinate.latitude);
+    XCTAssertEqual(camera.centerCoordinate.longitude, mkCamera.centerCoordinate.longitude);
+    XCTAssertEqual(camera.altitude, 1000);
+    XCTAssertEqual(camera.altitude, mkCamera.altitude, @"Eye altitude in tilted camera should match MapKit.");
+    XCTAssertEqualWithAccuracy(camera.pitch, 65.3469146074, 0.01);
+    XCTAssertEqual(camera.pitch, mkCamera.pitch);
+    XCTAssertEqualWithAccuracy(camera.heading, 115.066396383, 0.01);
+    XCTAssertEqualWithAccuracy(camera.heading, mkCamera.heading, 0.01);
+}
+
 - (void)testViewingDistanceInitialization {
     CLLocationCoordinate2D fountainSquare = CLLocationCoordinate2DMake(39.10152215, -84.5124439696089);
     MGLMapCamera *camera = [MGLMapCamera cameraLookingAtCenterCoordinate:fountainSquare

diff --git a/platform/ios/CHANGELOG.md b/platform/ios/CHANGELOG.md
@@ -16,6 +16,7 @@ Mapbox welcomes participation and contributions from everyone. Please read [CONT
 ### Other changes	
 
 * Deprecated the `+[MGLMapCamera cameraLookingAtCenterCoordinate:fromDistance:pitch:heading:]` method in favor of `+[MGLMapCamera cameraLookingAtCenterCoordinate:altitude:pitch:heading:]` and a temporarily named `+[MGLMapCamera cameraLookingAtCenterCoordinate:correctlyFromDistance:pitch:heading:]`. ([#12966](https://github.com/mapbox/mapbox-gl-native/pull/12966))
+* Fixed an issue where `+[MGLMapCamera cameraLookingAtCenterCoordinate:fromEyeCoordinate:eyeAltitude:]` created a camera looking from the wrong eye coordinate. ([#12966](https://github.com/mapbox/mapbox-gl-native/pull/12966))
 * Added an `MGLMapCamera.viewingDistance` property based on the existing `MGLMapCamera.altitude` property. ([#12966](https://github.com/mapbox/mapbox-gl-native/pull/12966))
 * Fixed an issue where `-[MGLMapSnapshotter startWithQueue:completionHandler:]` failed to call its completion handler in some cases. ([#12355](https://github.com/mapbox/mapbox-gl-native/pull/12355))
 * Fixed bugs in coercion expression operators ("to-array" applied to empty arrays, "to-color" applied to colors, and "to-number" applied to null) [#12864](https://github.com/mapbox/mapbox-gl-native/pull/12864)

diff --git a/platform/macos/CHANGELOG.md b/platform/macos/CHANGELOG.md
@@ -14,6 +14,7 @@
 ### Other changes	
 
 * Deprecated the `+[MGLMapCamera cameraLookingAtCenterCoordinate:fromDistance:pitch:heading:]` method in favor of `+[MGLMapCamera cameraLookingAtCenterCoordinate:altitude:pitch:heading:]` and a temporarily named `+[MGLMapCamera cameraLookingAtCenterCoordinate:correctlyFromDistance:pitch:heading:]`. ([#12966](https://github.com/mapbox/mapbox-gl-native/pull/12966))
+* Fixed an issue where `+[MGLMapCamera cameraLookingAtCenterCoordinate:fromEyeCoordinate:eyeAltitude:]` created a camera looking from the wrong eye coordinate. ([#12966](https://github.com/mapbox/mapbox-gl-native/pull/12966))
 * Added an `MGLMapCamera.viewingDistance` property based on the existing `MGLMapCamera.altitude` property. ([#12966](https://github.com/mapbox/mapbox-gl-native/pull/12966))
 * Fixed an issue where `-[MGLMapSnapshotter startWithQueue:completionHandler:]` failed to call its completion handler in some cases. ([#12355](https://github.com/mapbox/mapbox-gl-native/pull/12355))
 * Fixed an issue where `MGLMapView` produced a designable error in Interface Builder storyboards in Xcode 10. ([#12883](https://github.com/mapbox/mapbox-gl-native/pull/12883))