我试图获取一个点的坐标,该点距起始位置一定距离,但最终结果是错误的。
首先,我计算起始位置和所需目的地之间的角度:
private func calculateAngleBetweenLocations(currentLocation: CLLocationCoordinate2D, targetLocation: CLLocationCoordinate2D) -> Double {
let fLat = self.degreesToRadians(currentLocation.latitude);
let fLng = self.degreesToRadians(currentLocation.longitude);
let tLat = self.degreesToRadians(targetLocation.latitude);
let tLng = self.degreesToRadians(targetLocation.longitude);
let deltaLng = tLng - fLng
let y = sin(deltaLng) * cos(tLat)
let x = cos(fLat) * sin(tLat) - sin(fLat) * cos(tLat) * cos(deltaLng)
let bearing = atan2(y, x)
return self.radiansToDegrees(bearing)
}
然后,我计算给定距离的新点:
private func coordinatesForMovement(endLocation: CLLocationCoordinate2D, distance: Double) -> CLLocationCoordinate2D {
let angle = self.calculateAngleBetweenLocations(self.currentLocation, targetLocation: endLocation)
let x = self.currentLocation.latitude + distance * cos(angle)
let y = self.currentLocation.longitude + distance * sin(angle)
return CLLocationCoordinate2D(latitude: x, longitude: y)
}
和this是结果(脚是起始位置,蓝色标记是目的地,红色标记是新计算点所在的位置)。我尝试过以米和公里为单位传递距离以及所有其他浮点位置,但从未得到正确的结果。有任何想法吗?
最佳答案
好吧,经过一番挖掘,我发现 this答案,这解决了我的问题。这是我的完整解决方案:
internal func moveToLocation(location: CLLocationCoordinate2D, distance: Double) {
let angle = self.calculateAngleBetweenLocations(self.currentLocation, targetLocation: location)
let newLocation = self.coordinates(self.currentLocation, atDistance: distance, atAngle: angle)
self.moveUser(newLocation: newLocation)
}
private func coordinates(startingCoordinates: CLLocationCoordinate2D, atDistance: Double, atAngle: Double) -> CLLocationCoordinate2D {
let distanceRadians = atDistance / 6371
let bearingRadians = self.degreesToRadians(atAngle)
let fromLatRadians = self.degreesToRadians(startingCoordinates.latitude)
let fromLonRadians = self.degreesToRadians(startingCoordinates.longitude)
let toLatRadians = asin(sin(fromLatRadians) * cos(distanceRadians) + cos(fromLatRadians) * sin(distanceRadians) * cos(bearingRadians))
var toLonRadians = fromLonRadians + atan2(sin(bearingRadians) * sin(distanceRadians) * cos(fromLatRadians), cos(distanceRadians) - sin(fromLatRadians) * sin(toLatRadians));
toLonRadians = fmod((toLonRadians + 3 * M_PI), (2 * M_PI)) - M_PI
let lat = self.radiansToDegrees(toLatRadians)
let lon = self.radiansToDegrees(toLonRadians)
return CLLocationCoordinate2D(latitude: lat, longitude: lon)
}
private func calculateAngleBetweenLocations(currentLocation: CLLocationCoordinate2D, targetLocation: CLLocationCoordinate2D) -> Double {
let fLat = self.degreesToRadians(currentLocation.latitude);
let fLng = self.degreesToRadians(currentLocation.longitude);
let tLat = self.degreesToRadians(targetLocation.latitude);
let tLng = self.degreesToRadians(targetLocation.longitude);
let deltaLng = tLng - fLng
let y = sin(deltaLng) * cos(tLat)
let x = cos(fLat) * sin(tLat) - sin(fLat) * cos(tLat) * cos(deltaLng)
let bearing = atan2(y, x)
return self.radiansToDegrees(bearing)
}
private func degreesToRadians(x: Double) -> Double {
return M_PI * x / 180.0
}
private func radiansToDegrees(x: Double) -> Double {
return x * 180.0 / M_PI
}
关于ios - 使用起始位置和距离计算新坐标,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/52683664/