This example creates a map using the Gall-Peters projection, rather than the default Mercator projection.
Read the documentation .
TypeScript
// This example defines an image map type using the Gall-Peters // projection. // https://en.wikipedia.org/wiki/Gall%E2%80%93Peters_projection function initMap () : void { // Create a map. Use the Gall-Peters map type. const map = new google . maps . Map ( document . getElementById ( "map" ) as HTMLElement , { zoom : 0 , center : { lat : 0 , lng : 0 }, mapTypeControl : false , } ); initGallPeters (); map . mapTypes . set ( "gallPeters" , gallPetersMapType ); map . setMapTypeId ( "gallPeters" ); // Show the lat and lng under the mouse cursor. const coordsDiv = document . getElementById ( "coords" ) as HTMLElement ; map . controls [ google . maps . ControlPosition . TOP_CENTER ]. push ( coordsDiv ); map . addListener ( "mousemove" , ( event : google.maps.MapMouseEvent ) = > { coordsDiv . textContent = "lat: " + Math . round ( event . latLng ! . lat ()) + ", " + "lng: " + Math . round ( event . latLng ! . lng ()); }); // Add some markers to the map. map . data . setStyle (( feature ) = > { return { title : feature.getProperty ( "name" ) as string , optimized : false , }; }); map . data . addGeoJson ( cities ); } let gallPetersMapType ; function initGallPeters () { const GALL_PETERS_RANGE_X = 800 ; const GALL_PETERS_RANGE_Y = 512 ; // Fetch Gall-Peters tiles stored locally on our server. gallPetersMapType = new google . maps . ImageMapType ({ getTileUrl : function ( coord , zoom ) { const scale = 1 << zoom ; // Wrap tiles horizontally. const x = (( coord . x % scale ) + scale ) % scale ; // Don't wrap tiles vertically. const y = coord . y ; if ( y < 0 || y > = scale ) return "" ; return ( "https://developers.google.com/maps/documentation/" + "javascript/examples/full/images/gall-peters_" + zoom + "_" + x + "_" + y + ".png" ); }, tileSize : new google . maps . Size ( GALL_PETERS_RANGE_X , GALL_PETERS_RANGE_Y ), minZoom : 0 , maxZoom : 1 , name : "Gall-Peters" , }); // Describe the Gall-Peters projection used by these tiles. gallPetersMapType . projection = { fromLatLngToPoint : function ( latLng ) { const latRadians = ( latLng . lat () * Math . PI ) / 180 ; return new google . maps . Point ( GALL_PETERS_RANGE_X * ( 0.5 + latLng . lng () / 360 ), GALL_PETERS_RANGE_Y * ( 0.5 - 0.5 * Math . sin ( latRadians )) ); }, fromPointToLatLng : function ( point , noWrap ) { const x = point . x / GALL_PETERS_RANGE_X ; const y = Math . max ( 0 , Math . min ( 1 , point . y / GALL_PETERS_RANGE_Y )); return new google . maps . LatLng ( ( Math . asin ( 1 - 2 * y ) * 180 ) / Math . PI , - 180 + 360 * x , noWrap ); }, }; } // GeoJSON, describing the locations and names of some cities. const cities = { type : "FeatureCollection" , features : [ { type : "Feature" , geometry : { type : "Point" , coordinates : [ - 87.65 , 41.85 ] }, properties : { name : "Chicago" }, }, { type : "Feature" , geometry : { type : "Point" , coordinates : [ - 149.9 , 61.218 ] }, properties : { name : "Anchorage" }, }, { type : "Feature" , geometry : { type : "Point" , coordinates : [ - 99.127 , 19.427 ] }, properties : { name : "Mexico City" }, }, { type : "Feature" , geometry : { type : "Point" , coordinates : [ - 0.126 , 51.5 ] }, properties : { name : "London" }, }, { type : "Feature" , geometry : { type : "Point" , coordinates : [ 28.045 , - 26.201 ] }, properties : { name : "Johannesburg" }, }, { type : "Feature" , geometry : { type : "Point" , coordinates : [ 15.322 , - 4.325 ] }, properties : { name : "Kinshasa" }, }, { type : "Feature" , geometry : { type : "Point" , coordinates : [ 151.207 , - 33.867 ] }, properties : { name : "Sydney" }, }, { type : "Feature" , geometry : { type : "Point" , coordinates : [ 0 , 0 ] }, properties : { name : "0°N 0°E" }, }, ], }; declare global { interface Window { initMap : () = > void ; } } window . initMap = initMap ;
JavaScript
// This example defines an image map type using the Gall-Peters // projection. // https://en.wikipedia.org/wiki/Gall%E2%80%93Peters_projection function initMap () { // Create a map. Use the Gall-Peters map type. const map = new google . maps . Map ( document . getElementById ( "map" ), { zoom : 0 , center : { lat : 0 , lng : 0 }, mapTypeControl : false , }); initGallPeters (); map . mapTypes . set ( "gallPeters" , gallPetersMapType ); map . setMapTypeId ( "gallPeters" ); // Show the lat and lng under the mouse cursor. const coordsDiv = document . getElementById ( "coords" ); map . controls [ google . maps . ControlPosition . TOP_CENTER ]. push ( coordsDiv ); map . addListener ( "mousemove" , ( event ) = > { coordsDiv . textContent = "lat: " + Math . round ( event . latLng . lat ()) + ", " + "lng: " + Math . round ( event . latLng . lng ()); }); // Add some markers to the map. map . data . setStyle (( feature ) = > { return { title : feature . getProperty ( "name" ), optimized : false , }; }); map . data . addGeoJson ( cities ); } let gallPetersMapType ; function initGallPeters () { const GALL_PETERS_RANGE_X = 800 ; const GALL_PETERS_RANGE_Y = 512 ; // Fetch Gall-Peters tiles stored locally on our server. gallPetersMapType = new google . maps . ImageMapType ({ getTileUrl : function ( coord , zoom ) { const scale = 1 << zoom ; // Wrap tiles horizontally. const x = (( coord . x % scale ) + scale ) % scale ; // Don't wrap tiles vertically. const y = coord . y ; if ( y < 0 || y > = scale ) return "" ; return ( "https://developers.google.com/maps/documentation/" + "javascript/examples/full/images/gall-peters_" + zoom + "_" + x + "_" + y + ".png" ); }, tileSize : new google . maps . Size ( GALL_PETERS_RANGE_X , GALL_PETERS_RANGE_Y ), minZoom : 0 , maxZoom : 1 , name : "Gall-Peters" , }); // Describe the Gall-Peters projection used by these tiles. gallPetersMapType . projection = { fromLatLngToPoint : function ( latLng ) { const latRadians = ( latLng . lat () * Math . PI ) / 180 ; return new google . maps . Point ( GALL_PETERS_RANGE_X * ( 0.5 + latLng . lng () / 360 ), GALL_PETERS_RANGE_Y * ( 0.5 - 0.5 * Math . sin ( latRadians )), ); }, fromPointToLatLng : function ( point , noWrap ) { const x = point . x / GALL_PETERS_RANGE_X ; const y = Math . max ( 0 , Math . min ( 1 , point . y / GALL_PETERS_RANGE_Y )); return new google . maps . LatLng ( ( Math . asin ( 1 - 2 * y ) * 180 ) / Math . PI , - 180 + 360 * x , noWrap , ); }, }; } // GeoJSON, describing the locations and names of some cities. const cities = { type : "FeatureCollection" , features : [ { type : "Feature" , geometry : { type : "Point" , coordinates : [ - 87.65 , 41.85 ] }, properties : { name : "Chicago" }, }, { type : "Feature" , geometry : { type : "Point" , coordinates : [ - 149.9 , 61.218 ] }, properties : { name : "Anchorage" }, }, { type : "Feature" , geometry : { type : "Point" , coordinates : [ - 99.127 , 19.427 ] }, properties : { name : "Mexico City" }, }, { type : "Feature" , geometry : { type : "Point" , coordinates : [ - 0.126 , 51.5 ] }, properties : { name : "London" }, }, { type : "Feature" , geometry : { type : "Point" , coordinates : [ 28.045 , - 26.201 ] }, properties : { name : "Johannesburg" }, }, { type : "Feature" , geometry : { type : "Point" , coordinates : [ 15.322 , - 4.325 ] }, properties : { name : "Kinshasa" }, }, { type : "Feature" , geometry : { type : "Point" , coordinates : [ 151.207 , - 33.867 ] }, properties : { name : "Sydney" }, }, { type : "Feature" , geometry : { type : "Point" , coordinates : [ 0 , 0 ] }, properties : { name : "0°N 0°E" }, }, ], }; window . initMap = initMap ;
CSS
/* * Always set the map height explicitly to define the size of the div element * that contains the map. */ # map { height : 100 % ; } /* * Optional: Makes the sample page fill the window. */ html , body { height : 100 % ; margin : 0 ; padding : 0 ; } # coords { background-color : black ; color : white ; padding : 5 px ; }
HTML
<html> <head> <title>Custom Map Projections</title> <link rel="stylesheet" type="text/css" href="./style.css" /> <script type="module" src="./index.js"></script> </head> <body> <div id="map"></div> <div id="coords"></div> <!-- The `defer` attribute causes the script to execute after the full HTML document has been parsed. For non-blocking uses, avoiding race conditions, and consistent behavior across browsers, consider loading using Promises. See https://developers.google.com/maps/documentation/javascript/load-maps-js-api for more information. --> <script src="https://maps.googleapis.com/maps/api/js?key=AIzaSyB41DRUbKWJHPxaFjMAwdrzWzbVKartNGg&callback=initMap&v=weekly" defer ></script> </body> </html>
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git clone - b sample - map - projection - simple https : //github.com/googlemaps/js-samples.gitcd js - samplesnpm inpm start
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git checkout sample - SAMPLE_NAMEnpm inpm start
