How to except area from polygon in google maps api

问题:

I have coordinates of two polygons (P1 and P2) to create it on google maps. How cut P2 from P1 when P2 is located in P1? For example http://quality.iro38.ru/CI/question_about_map.php

This is my js:

var triangleCoords = [
    new google.maps.LatLng(25.774252, -80.190262),
    new google.maps.LatLng(18.466465, -66.118292),
    new google.maps.LatLng(32.321384, -64.75737),
    new google.maps.LatLng(25.774252, -80.190262)
];
var triangleCoords1 = [
    new google.maps.LatLng(29,-69),
    new google.maps.LatLng(23,-72),
    new google.maps.LatLng(25,-70),
    new google.maps.LatLng(29,-69)
];
bermudaTriangle = new google.maps.Polygon({
    paths: [triangleCoords, triangleCoords1],
    strokeColor: '#FF0000',
    strokeOpacity: 0.8,
    strokeWeight: 2,
    fillColor: '#FF0000',
    fillOpacity: 0.35
});
bermudaTriangle.setMap(map);

回答1:

You need to make the winding direction of the inner polygon opposite the winding direction of the outer polygon.

working fiddle

code snippet:

var map;

function initialize() {
  map = new google.maps.Map(
    document.getElementById("map_canvas"), {
      center: new google.maps.LatLng(37.4419, -122.1419),
      zoom: 13,
      mapTypeId: google.maps.MapTypeId.ROADMAP
    });
  var bounds = new google.maps.LatLngBounds();
  var triangleCoords = [
    new google.maps.LatLng(25.774252, -80.190262),
    new google.maps.LatLng(18.466465, -66.118292),
    new google.maps.LatLng(32.321384, -64.75737),
    new google.maps.LatLng(25.774252, -80.190262)
  ];
  var triangleCoords1 = [
    new google.maps.LatLng(29, -69),
    new google.maps.LatLng(25, -70),
    new google.maps.LatLng(23, -72),
    new google.maps.LatLng(29, -69)

  ];
  for (var i = 0; i < triangleCoords.length; i++) {
    bounds.extend(triangleCoords[i]);
  }
  for (var i = 0; i < triangleCoords1.length; i++) {
    bounds.extend(triangleCoords1[i]);
  }
  map.fitBounds(bounds);

  bermudaTriangle = new google.maps.Polygon({
    paths: [triangleCoords, triangleCoords1],
    strokeColor: '#FF0000',
    strokeOpacity: 0.8,
    strokeWeight: 2,
    fillColor: '#FF0000',
    fillOpacity: 0.35
  });
  bermudaTriangle.setMap(map);
}
google.maps.event.addDomListener(window, "load", initialize);

html,
body,
#map_canvas {
  height: 100%;
  width: 100%;
  margin: 0px;
  padding: 0px
}

<script src="https://maps.googleapis.com/maps/api/js"></script>
<div id="map_canvas" style="border: 2px solid #3872ac;"></div>