Showing Tile and Pixel Coordinates is not giving expected output?-CodePudding

I want to create a map that displays a window with the latitude, longitude, and world, pixel, and tile coordinates for a city. It also shows how these values change as the zoom level is adjusted. But the below code is not running expectedly

The html is as follows:

<!DOCTYPE html>
<html>
  <head>
    <title>Showing Pixel and Tile Coordinates</title>
    <script src="https://polyfill.io/v3/polyfill.min.js?features=default"></script>
 
  </head>
  <body>
    <div id="map"></div>

  
    <script
      src="https://maps.googleapis.com/maps/api/js?key=AIzaSyB41DRUbKWJHPxaFjMAwdrzWzbVKartNGg&callback=initMap&v=weekly&channel=2"
      async
    ></script>
  </body>
</html>

The CSS is

#map {
  height: 100%;
}

html,
body {
  height: 100%;
  margin: 0;
  padding: 0;
}

The javascript i use is as follows:

function initMap() {
  const chicago = new google.maps.LatLng(41.85, -87.65);
  const map = new google.maps.Map(document.getElementById("map"), {
    center: chicago,
    zoom: 3,
  });
  const coordInfoWindow = new google.maps.InfoWindow();

  coordInfoWindow.setContent(createInfoWindowContent(chicago, map.getZoom()));
  coordInfoWindow.setPosition(chicago);
  coordInfoWindow.open(map);
  map.addListener("zoom_changed", () => {
    coordInfoWindow.setContent(createInfoWindowContent(chicago, map.getZoom()));
    coordInfoWindow.open(map);
  });
}

const TILE_SIZE = 256;

function createInfoWindowContent(latLng, zoom) {
  const scale = 1 << zoom;
  const worldCoordinate = project(latLng);
  const pixelCoordinate = new google.maps.Point(
    Math.floor(worldCoordinate.x * scale),
    Math.floor(worldCoordinate.y * scale)
  );
  const tileCoordinate = new google.maps.Point(
    Math.floor((worldCoordinate.x * scale) / TILE_SIZE),
    Math.floor((worldCoordinate.y * scale) / TILE_SIZE)
  );
  return [
    "Chicago, IL",
    "LatLng: "   latLng,
    "Zoom level: "   zoom,
    "World Coordinate: "   worldCoordinate,
    "Pixel Coordinate: "   pixelCoordinate,
    "Tile Coordinate: "   tileCoordinate,
  ].join("<br>");
}


function project(latLng) {
  let siny = Math.sin((latLng.lat() * Math.PI) / 180);


  siny = Math.max(siny, -0.9999), 0.9999);
  return new google.maps.Point(
    TILE_SIZE * (0.5   latLng.lng() / 360)
  );
}

CodePudding user response：

i run your whole code and i find out that your JS script is missing some code. Please change the last 4 lines of JS with this code:

  siny = Math.min(Math.max(siny, -0.9999), 0.9999);
  return new google.maps.Point(
    TILE_SIZE * (0.5   latLng.lng() / 360),
    TILE_SIZE * (0.5 - Math.log((1   siny) / (1 - siny)) / (4 * Math.PI))
  );