如何测试LatLng点是否在圆形范围内?(谷歌地图JavaScript v3)
getBounds()方法返回圆的边界框,也就是一个矩形,所以如果一个点在圆外但在边界框内,你会得到错误的答案。
如何测试LatLng点是否在圆形范围内?(谷歌地图JavaScript v3)
getBounds()方法返回圆的边界框,也就是一个矩形,所以如果一个点在圆外但在边界框内,你会得到错误的答案。
使用球面几何库(确保在API中包含它)
function pointInCircle(point, radius, center)
{
return (google.maps.geometry.spherical.computeDistanceBetween(point, center) <= radius)
}
(x1 - x2)^2 + (y1 - y2)^2 <= D^2
new google.maps.Circle({
map : map,
center : new google.maps.LatLng(lat,lng),
strokeColor:'#00FFCC',
strokeWeight:2,
fillOpacity:0,
radius:radiusm
});
并将勾股定理应用于坐标:但在这种情况下为了使它成为一个“真正”的圆,因为纬度和经度之间的比率在不同的纬度上是不同的, 你至少应该像这样进行调整:
var kmRadius = 100; //(radius of 100 km)
var lat_gap = kmRadius/111.1;
var lng_gap = lat_gap / Math.cos(lat / (Math.PI/180));
为什么不用毕达哥拉斯定理简单地计算一下呢?你知道a²+b²=c²。如果c小于r(半径),那么它就在内部。
var isInside=Math.pow(x1 - x2, 2) + Math.pow(y1 - y2, 2) >= r*r;
试试这个(Javascript):
const toRadians = (val) => {
return val * Math.PI / 180;
}
const toDegrees = (val) => {
return val * 180 / Math.PI;
}
// Calculate a point winthin a circle
// circle ={center:LatLong, radius: number} // in metres
const pointInsideCircle = (point, circle) => {
let center = circle.center;
let distance = distanceBetween(point, center);
return distance < circle.radius; // Use '<=' if you want to get all points in the border
};
const distanceBetween = (point1, point2) => {
var R = 6371e3; // metres
var φ1 = toRadians(point1.latitude);
var φ2 = toRadians(point2.latitude);
var Δφ = toRadians(point2.latitude - point1.latitude);
var Δλ = toRadians(point2.longitude - point1.longitude);
var a = Math.sin(Δφ / 2) * Math.sin(Δφ / 2) +
Math.cos(φ1) * Math.cos(φ2) *
Math.sin(Δλ / 2) * Math.sin(Δλ / 2);
var c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1 - a));
return R * c;
}
参考文献: http://www.movable-type.co.uk/scripts/latlong.html
这个npm帮助模块执行相同的操作,并返回一个布尔值,用于判断该项是否在圆内。
const toRadians = val => val * Math.PI / 180;
const toDegrees = val => val * 180 / Math.PI;
- pmrotule类似这样的代码应该就能解决问题了(未经测试):
public boolean pointInCircle(Circle c, LatLng coord) {
Rectangle r = c.getBounds();
double rectX = r.getX();
double rectY = r.getY();
double rectWidth = r.getWidth();
double rectHeight = r.getHeight();
double circleCenterX = rectX + rectWidth/2;
double circleCenterY = rectY + rectHeight/2;
double lat = coord.getLatitude();
double lon = coord.getLongitude();
// Point in circle if (x−h)^2 + (y−k)^2 <= r^2
double rSquared = Math.pow(rectWidth/2, 2);
double point = Math.pow(lat - circleCenterX, 2) + Math.pow(lon - circleCenterY, 2);
return (point <= rSquared) ? true : false;
}