无法绘制 MKPolylineView 交叉经度 +/-180

我在 MKMapView 上绘制 MKPolylineView 时遇到问题。该线路代表一次环游世界的旅行，起点和终点均在纽约附近，始终向东行驶。从日本到旧金山的旅程的其中一段跨越太平洋，因此经度为 +/-180。 MKPolylineView 确实连接了这两点，但它的行进方向错误。也就是说，该线路从日本向西返回旧金山，而不是向东穿越太平洋。我没有看到任何选项可以让我指定线段应沿哪个方向移动以连接两点。

简单来说，MKMapView 似乎不明白世界是圆的。有没有一种方法可以让我按照预期划线，从日本向东到达旧金山？

我有一个屏幕截图，清楚地显示了问题：
折线 http://www.builtlight.org/pub/MKPolylineView.png

这似乎是 MKMapView 的限制。

解决方法是将 +/-180 交叉点分成“东”和“西”部分。

对于环球旅行（结束 == 开始），您可以将交叉路口的“西”部分放在折线的前面。
例如：

CLLocationCoordinate2D newYorkCoord = CLLocationCoordinate2DMake(40.7141667, -74.0063889);
CLLocationCoordinate2D londonCoord = CLLocationCoordinate2DMake(51.5, -0.116667);
CLLocationCoordinate2D japanCoord = CLLocationCoordinate2DMake(36, 138);
CLLocationCoordinate2D sanFranciscoCoord = CLLocationCoordinate2DMake(37.775, -122.4183333);

CLLocationCoordinate2D japanToSFMidpointEast;
//use average calc as crude way to find midpoint...
japanToSFMidpointEast.latitude = (japanCoord.latitude + sanFranciscoCoord.latitude)/2.0;
japanToSFMidpointEast.longitude = 180;

CLLocationCoordinate2D japanToSFMidpointWest;
japanToSFMidpointWest.latitude = japanToSFMidpointEast.latitude;
japanToSFMidpointWest.longitude = -180;

int pointsCount = 6;
CLLocationCoordinate2D *points = malloc(pointsCount * sizeof(CLLocationCoordinate2D));
points[0] = japanToSFMidpointWest;
points[1] = sanFranciscoCoord;
points[2] = newYorkCoord;
points[3] = londonCoord;
points[4] = japanCoord;
points[5] = japanToSFMidpointEast;
MKPolyline *polyline = [MKPolyline polylineWithCoordinates:points count:pointsCount];
[mapView addOverlay:polyline];
free(points);
points = NULL;

如果旅行不是环球旅行（结束！=开始），则必须使用两条折线。
这个例子是从日本到SF的：

CLLocationCoordinate2D japanCoord = CLLocationCoordinate2DMake(36, 138);
CLLocationCoordinate2D sanFranciscoCoord = CLLocationCoordinate2DMake(37.775, -122.4183333);

CLLocationCoordinate2D japanToSFMidpointEast;
japanToSFMidpointEast.latitude = (japanCoord.latitude + sanFranciscoCoord.latitude)/2.0;
japanToSFMidpointEast.longitude = 180;

CLLocationCoordinate2D japanToSFMidpointWest;
japanToSFMidpointWest.latitude = japanToSFMidpointEast.latitude;
japanToSFMidpointWest.longitude = -180;

int eastPointsCount = 2;
CLLocationCoordinate2D *eastPoints = malloc(eastPointsCount * sizeof(CLLocationCoordinate2D));
eastPoints[0] = japanCoord;
eastPoints[1] = japanToSFMidpointEast;
MKPolyline *eastPolyline = [MKPolyline polylineWithCoordinates:eastPoints count:eastPointsCount];
[mapView addOverlay:eastPolyline];
free(eastPoints);
eastPoints = NULL;

int westPointsCount = 2;
CLLocationCoordinate2D *westPoints = malloc(westPointsCount * sizeof(CLLocationCoordinate2D));
westPoints[0] = japanToSFMidpointWest;
westPoints[1] = sanFranciscoCoord;
MKPolyline *westPolyline = [MKPolyline polylineWithCoordinates:westPoints count:westPointsCount];
[mapView addOverlay:westPolyline];
free(westPoints);
westPoints = NULL;