[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.

platform/darwin/src/MGLMapCamera.mm

@@ -1,7 +1,9 @@
 #import "MGLMapCamera.h"
 #import "MGLGeometry_Private.h"
 
-#include <mbgl/util/projection.hpp>
+#import <CoreLocation/CoreLocation.h>
+
+#include <mbgl/math/wrap.hpp>
 
 BOOL MGLEqualFloatWithAccuracy(CGFloat left, CGFloat right, CGFloat accuracy)
 {
@@ -27,17 +29,15 @@ + (instancetype)cameraLookingAtCenterCoordinate:(CLLocationCoordinate2D)centerCo
  CLLocationDirection heading = -1;
  CGFloat pitch = -1;
  if (CLLocationCoordinate2DIsValid(centerCoordinate) && CLLocationCoordinate2DIsValid(eyeCoordinate)) {
- mbgl::LatLng centerLatLng = MGLLatLngFromLocationCoordinate2D(centerCoordinate);
- mbgl::LatLng eyeLatLng = MGLLatLngFromLocationCoordinate2D(eyeCoordinate);
-
- 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()));
+ heading = MGLDirectionBetweenCoordinates(eyeCoordinate, centerCoordinate);
 
- 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

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