Multi tool use

How to computerArea of a polygon with holes in Google maps? [on hold]

Polygon with Hole is presented by multiple paths, but how to computerArea of a polygon with holes in Google maps?

My first attempt is to sum up all area of each path from google.maps.geometry.spherical.computeArea(path).

function polygonArea1(polygon) {
var paths = polygon.getPaths().getArray();
var a = 0;
for (var i = 0; i < paths.length; ++i) {
a += google.maps.geometry.spherical.computeArea(paths[i]);
}
return a;
}

It does not work because this computeArea() is unsigned!
What is your solution or suggestion?

#simple polygon: one path, no intersection.
42.42883995722236,-71.60123305060961
42.42874096809684,-71.60132961013414
42.42868157454647,-71.60120891072847
42.42878155365721,-71.60111637451746

#complex polygon 1: one path but has intersection.
42.42869345326113,-71.60101981499292
42.42879343235287,-71.6009259376774
42.42860733252938,-71.60083742477991
42.42871028143621,-71.60075025298693

#complex polygon 2: two or more paths without intersection.
42.42869048358269,-71.60062150695421
42.428780563765905,-71.60052092411615
42.42868751390411,-71.60037072041132
42.42859347400984,-71.60045386889078
&1th
42.42864989794301,-71.60045118668177
42.428680584633994,-71.60043174066641
42.428724139911225,-71.60050751307108
42.42870137240295,-71.6005464051018

#complex polygon 3: two or more paths with intersection.
42.42869642293929,-71.60020174124338
42.42861624157606,-71.60027281978228
42.42855882769735,-71.60014273264505
42.42863603945308,-71.60007433631517
&1th
42.428637029313705,-71.60019637682535
42.4287300792654,-71.60011322834589
42.42871028143333,-71.60007165410616
42.428616241558124,-71.60015413203337

This question appears to be off-topic. The users who voted to close gave this specific reason:

1 Answer
1

class Polygon {

getPolygonArea(coords) {
let area = 0;
if (coords && coords.length > 0) {
area += Math.abs(this.getPolygonRingArea(coords[0]));
for (let i = 1; i < coords.length; i++) {
area -= Math.abs(this.getPolygonRingArea(coords[i]));
}
}
return area;
}

getRadiun(_) {
return _ * Math.PI / 180;
}

getPolygonRingArea(coords) {
let p1;
let p2;
let p3;
let lowerIndex;
let middleIndex;
let upperIndex;
let i;
let area = 0;
let coordsLength = coords.length;
const RADIUS = 6378137;

if (coordsLength > 2) {
for (i = 0; i < coordsLength; i++) {
if (i === coordsLength - 2) { // i = N-2
lowerIndex = coordsLength - 2;
middleIndex = coordsLength - 1;
upperIndex = 0;
} else if (i === coordsLength - 1) { // i = N-1
lowerIndex = coordsLength - 1;
middleIndex = 0;
upperIndex = 1;
} else { // i = 0 to N-3
lowerIndex = i;
middleIndex = i + 1;
upperIndex = i + 2;
}
p1 = coords[lowerIndex];
p2 = coords[middleIndex];
p3 = coords[upperIndex];
area += (this.getRadiun(p3[0]) - this.getRadiun(p1[0])) * Math.sin(this.getRadiun(p2[1]));
}

area = area * RADIUS * RADIUS / 2;
}

return area;
}
}

let coords = [
[
[-64.73, 32.31],
[-80.19, 25.76],
[-66.09, 18.43],
[-64.73, 32.31]
]
];

alert(new Polygon().getPolygonArea(coords));

This is the above logic to calculate the area of a Polygon and subtract the area of holes to get to the final area.

The format of coordinates -

let coords = [
[
[lng, lat],....
]
];