C++ Console - New lat/lon coordinate using azimuth and range [closed] - c++

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I would like assistance understanding this code I found during a search. I have been stuck for 2 weeks trying to get it and it's holding my project back. I am honestly trying to learn as I go and not just be a script kiddie about it, but this is much more complicated than the rest of my project even though I am trying. (I just learned about auto today while trying to understand this code, for example.)
I am working on a weather app and I know the lat/lon of the radar site. I need the lat/lon of a feature the radar has detected based off of the azimuth/range that the radar tells me (example, 271 degrees and 7 nautical miles). I need to understand how I can use this code below to convert the azimuth/range to a new lat lon coordinate. I don't require the other functions, just to be able to put my variables (starting coords, azimuth and range) and get a result. The code below looks to do much more than that, and it is confusing me.
I see the following code near the end :
auto coordinate = CoordinateToCoordinate(latitude1, longitude1, angle, meters);
... Which looks to be the part I would need out of this. I see how it's calculating it but once I dig deeper I just get myself confused. I have tried hacking at the code so much that I gave up and don't even have any examples.
I would like to be able to set my variables manually (example cin>>) and have the lat and lon output into a variable that I can save to a text file. I am able to do everything myself (ingesting the starting variables and writing the result to a text file) except the actual conversion itself.
How could I get started with this using the code below?
My example variables are :
Original Latitude = 29.4214
Original Longitude = -98.0142
Azimuth from Origin = 271 degrees
Range from Origin = 6 nautical miles (I can convert to meters if needed,
in this case it's 11112 meters)
The actual unedited code is below and a copy at this link. If I get help with this I won't just copy/paste and I will come back with the completed code after I make it. I really am wanting to understand as I go, so I can be better with these advanced topics and not be constrained in the future. Code below :
#include<iostream>
#include<iomanip>
#include<cmath>
// Source: // http://w...content-available-to-author-only...o.uk/scripts/latlong.html
static const double PI = 3.14159265358979323846, earthDiameterMeters = 6371.0 * 2 * 1000;
double degreeToRadian (const double degree) { return (degree * PI / 180); };
double radianToDegree (const double radian) { return (radian * 180 / PI); };
double CoordinatesToAngle (double latitude1,
const double longitude1,
double latitude2,
const double longitude2)
{
const auto longitudeDifference = degreeToRadian(longitude2 - longitude1);
latitude1 = degreeToRadian(latitude1);
latitude2 = degreeToRadian(latitude2);
using namespace std;
const auto x = (cos(latitude1) * sin(latitude2)) -
(sin(latitude1) * cos(latitude2) * cos(longitudeDifference));
const auto y = sin(longitudeDifference) * cos(latitude2);
const auto degree = radianToDegree(atan2(y, x));
return (degree >= 0)? degree : (degree + 360);
}
double CoordinatesToMeters (double latitude1,
double longitude1,
double latitude2,
double longitude2)
{
latitude1 = degreeToRadian(latitude1);
longitude1 = degreeToRadian(longitude1);
latitude2 = degreeToRadian(latitude2);
longitude2 = degreeToRadian(longitude2);
using namespace std;
auto x = sin((latitude2 - latitude1) / 2), y = sin((longitude2 - longitude1) / 2);
#if 1
return earthDiameterMeters * asin(sqrt((x * x) + (cos(latitude1) * cos(latitude2) * y * y)));
#else
auto value = (x * x) + (cos(latitude1) * cos(latitude2) * y * y);
return earthDiameterMeters * atan2(sqrt(value), sqrt(1 - value));
#endif
}
std::pair<double,double> CoordinateToCoordinate (double latitude,
double longitude,
double angle,
double meters)
{
latitude = degreeToRadian(latitude);
longitude = degreeToRadian(longitude);
angle = degreeToRadian(angle);
meters *= 2 / earthDiameterMeters;
using namespace std;
pair<double,double> coordinate;
coordinate.first = asin((sin(latitude) * cos(meters))
+ (cos(latitude) * sin(meters) * cos(angle)));
coordinate.second = longitude + atan2((sin(angle) * sin(meters) * cos(latitude)),
cos(meters) - (sin(latitude) * sin(coordinate.first)));
coordinate.first = radianToDegree(coordinate.first);
coordinate.second = radianToDegree(coordinate.second);
return coordinate;
}
int main ()
{
using namespace std;
const auto latitude1 = 12.968460, longitude1 = 77.641308,
latitude2 = 12.967862, longitude2 = 77.653130;
cout << std::setprecision(10);
cout << "(" << latitude1 << "," << longitude1 << ") --- "
"(" << latitude2 << "," << longitude2 << ")\n";
auto angle = CoordinatesToAngle(latitude1, longitude1, latitude2, longitude2);
cout << "Angle = " << angle << endl;
auto meters = CoordinatesToMeters(latitude1, longitude1, latitude2, longitude2);
cout << "Meters = " << meters << endl;
auto coordinate = CoordinateToCoordinate(latitude1, longitude1, angle, meters);
cout << "Destination = (" << coordinate.first << "," << coordinate.second << ")\n";
}

Answer 1

I think you just want something like this:
#include <iostream>
std::pair<double,double> CoordinateToCoordinate (double latitude,
double longitude,
double angle,
double meters)
{
...
...
}
using namespace std;
int main() {
double lat, lon, angle, dist;
cout << "Enter lat:"; cin >> lat;
cout << "Enter lon:"; cin >> lon;
cout << "Enter angle:"; cin >> angle;
cout << "Enter dist:"; cin >> dist;
auto coordinate = CoordinateToCoordinate(lat, lon, angle, dist);
cout << "Destination = (" << coordinate.first << "," << coordinate.second << ")\n";
}