Layer clipping example
<!DOCTYPE html> <html> <head> <title>Layer clipping example</title> <script src="https://code.jquery.com/jquery-1.11.2.min.js"></script> <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/css/bootstrap.min.css"> <script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/js/bootstrap.min.js"></script> <link rel="stylesheet" href="http://openlayers.org/en/3.8.1/css/ol.css" type="text/css"> <script src="http://openlayers.org/en/3.8.1/build/ol.js"></script> </head> <body> <div class="container-fluid"> <div class="row-fluid"> <div class="span12"> <div id="map" class="map"></div> </div> </div> </div> <script> var osm = new ol.layer.Tile({ source: new ol.source.OSM() }); var map = new ol.Map({ layers: [osm], target: 'map', controls: ol.control.defaults({ attributionOptions: /** @type {olx.control.AttributionOptions} */ ({ collapsible: false }) }), view: new ol.View({ center: [0, 0], zoom: 2 }) }); osm.on('precompose', function(event) { var ctx = event.context; ctx.save(); ctx.translate(ctx.canvas.width / 2, ctx.canvas.height / 2); ctx.scale(3, 3); ctx.translate(-75, -80); ctx.beginPath(); ctx.moveTo(75, 40); ctx.bezierCurveTo(75, 37, 70, 25, 50, 25); ctx.bezierCurveTo(20, 25, 20, 62.5, 20, 62.5); ctx.bezierCurveTo(20, 80, 40, 102, 75, 120); ctx.bezierCurveTo(110, 102, 130, 80, 130, 62.5); ctx.bezierCurveTo(130, 62.5, 130, 25, 100, 25); ctx.bezierCurveTo(85, 25, 75, 37, 75, 40); ctx.clip(); ctx.setTransform(1, 0, 0, 1, 0, 0); }); osm.on('postcompose', function(event) { var ctx = event.context; ctx.restore(); }); </script> </body> </html>