Witam,
znalazłem taki kod na stackoverflow który tworzy okręgi na mapie mapbox, ale nie bardzo rozumiem skąd tam się wzięły liczby 111.320 i 110.574, może ktoś z was mi to wytłumaczy.
https://stackoverflow.com/questions/37599561/drawing-a-circle-with-the-radius-in-miles-meters-with-mapbox-gl-js
var createGeoJSONCircle = function(center, radiusInKm, points) {
if(!points) points = 64;
var coords = {
latitude: center[1],
longitude: center[0]
};
var km = radiusInKm;
var ret = [];
var distanceX = km/(111.320*Math.cos(coords.latitude*Math.PI/180));
var distanceY = km/110.574;
var theta, x, y;
for(var i=0; i<points; i++) {
theta = (i/points)*(2*Math.PI);
x = distanceX*Math.cos(theta);
y = distanceY*Math.sin(theta);
ret.push([coords.longitude+x, coords.latitude+y]);
}
ret.push(ret[0]);
return {
"type": "geojson",
"data": {
"type": "FeatureCollection",
"features": [{
"type": "Feature",
"geometry": {
"type": "Polygon",
"coordinates": [ret]
}
}]
}
};
};