javascript - Gmap : how to draw squares on Earth (lat, lon)

Question

我想画一个正方形

rectangle = new google.maps.Rectangle();
var rectOptions = {
    strokeColor : "#FF0000",
    strokeOpacity : 0.8,
    strokeWeight : 2,
    fillOpacity : 0,
    map : map
};
rectangle.setOptions(rectOptions);

长度为 0.005'

google.maps.event.addListener(map, 'dragend', function() {

    var center = map.getCenter();
    rectangle.setBounds(new google.maps.LatLngBounds(
            new google.maps.LatLng(center.lat()-0.005, center.lng()-0.005),
            new google.maps.LatLng(center.lat()+0.005, center.lng()+0.005)));
});

但我发现这个正方形是一个靠近赤道的正方形，但在其他地方却很变形，是否有随纬度减小的函数以获得经度的等效长度？感谢您的帮助

编辑:正方形的高度 = cos(lat)width

Answer 1

来自 Andrew Leach 的评论:

function drawSquare(position=new google.maps.LatLng(41, 36.12), radius=0.001){

    var rectangle = new google.maps.Rectangle();
    var rectOptions = {
        strokeColor : "#FF0000",
        strokeOpacity : 0.8,
        strokeWeight : 2,
        fillOpacity : 0
    };
    rectangle.setOptions(rectOptions);

    var c = Math.cos(position.lat()* Math.PI / 180);
    rectangle.setBounds(new google.maps.LatLngBounds(
            new google.maps.LatLng(position.lat()-c*radius/2, position.lng()-radius/2),
            new google.maps.LatLng(position.lat()+c*radius/2, position.lng()+radius/2)));
    return rectangle;
}