balrog-kun/index.html

## index.html
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
 <head>
  <link rel="stylesheet" href="http://c.tile.openstreetmap.pl/leaflet/dist/leaflet.css" />
  <script type="application/javascript" src="http://c.tile.openstreetmap.pl/leaflet.bpg/bpgdec.js"></script>
  <script type="application/javascript" src="http://c.tile.openstreetmap.pl/leaflet/dist/leaflet.js"></script>
  <script type="application/javascript" src="http://c.tile.openstreetmap.pl/leaflet.bpg/TileLayer.BPG.js"></script>
  <style>
    body { margin:0; padding:0; }
    #map { position:absolute; top:0; bottom:0; width:100%; }
  </style>
 </head>
 <body>
  <style type='text/css'>
  body {
    font:20px/20px 'Helvetica Neue',sans-serif;
    background:#f2efe9;
  }
  #swipe {
    background:#222;
    position:absolute;
    bottom:0;
    left:0;
    right:0;
    z-index:1000;
    padding:10px;
    height:30px;
  }
  #swipe #handle {
    position:absolute;
    height:20px;
    padding:5px;
    background:#fff;
    font-weight:bold;
    border:1px solid #333;
    color:blue;
    cursor:pointer;
    -webkit-user-select: none;
  }
  .map-attribution {
    bottom: 50px;
  }
  #osm1 {
    position:absolute;
    left:10px;
    top:0px;
    z-index:99;
  }
  #osm2 {
    position:absolute;
    right:10px;
    top:0px;
    z-index:99;
  }
  </style>
  <div id='swipe'>
   <div id='handle'>drag</div>
  </div>
  <div id='map' />
  <h1 id='osm1'>.png</h1>
  <h1 id='osm2'>.bpg at -q 32 (62% ratio)</h1>
  <script>
  var map = L.map('map');
  var l0 = new L.TileLayer(
    'http://c.tile.openstreetmap.pl/osmapa.pl/{z}/{x}/{y}.png', {
      maxZoom: 18,
      attribution: 'Dane <a href="http://osm.org/">OpenStreetMap</a>',
    });
  var l1 = new L.TileLayer.BPG(
    'http://c.tile.openstreetmap.pl/osmapa.pl.bpg/{z}/{x}/{y}.bpg', {
      maxZoom: 18,
      attribution: 'Dane <a href="http://osm.org/">OpenStreetMap</a>',
    });
  map.addLayer(l0);
  map.addLayer(l1);
  map.setView(new L.LatLng(52, 21), 16);

  var handle = document.getElementById('handle'),
      dragging = false,
      divide;

  handle.onmousedown = function() { dragging = true; return false; }
  document.onmouseup = function() { dragging = false; }
  document.onmousemove = function(e) {
    if (!dragging)
      return;
    setDivide(map.mouseEventToContainerPoint(e).x);
  }

  function setDivide(x) {
    var size = map.getSize();
    divide = Math.max(40, Math.min(x, size.x - 40));
    handle.style.left = (divide - 40) + 'px';
    updateClip();
  }

  function updateClip() {
    var size = map.getSize();
    var offset = map.containerPointToLayerPoint(L.point(0, 0));
    l0.getContainer().style.clip = 'rect(' + offset.y + 'px ' +
      (offset.x + divide) + 'px ' +
      (offset.y + size.y) + 'px ' +
      offset.x + 'px)';
    l1.getContainer().style.clip = 'rect(' + offset.y + 'px ' +
      (offset.x + size.x) + 'px ' +
      (offset.y + size.y) + 'px ' +
      (offset.x + divide) + 'px)';
  }

  setDivide(400);
  map.on('move', updateClip);
  </script>
 </body>
</html>
	<?xml version="1.0" encoding="UTF-8"?>
	<!DOCTYPE html>
	<html xmlns="http://www.w3.org/1999/xhtml">
	<head>
	<link rel="stylesheet" href="http://c.tile.openstreetmap.pl/leaflet/dist/leaflet.css" />
	<script type="application/javascript" src="http://c.tile.openstreetmap.pl/leaflet.bpg/bpgdec.js"></script>
	<script type="application/javascript" src="http://c.tile.openstreetmap.pl/leaflet/dist/leaflet.js"></script>
	<script type="application/javascript" src="http://c.tile.openstreetmap.pl/leaflet.bpg/TileLayer.BPG.js"></script>
	<style>
	body { margin:0; padding:0; }
	#map { position:absolute; top:0; bottom:0; width:100%; }
	</style>
	</head>
	<body>
	<style type='text/css'>
	body {
	font:20px/20px 'Helvetica Neue',sans-serif;
	background:#f2efe9;
	}
	#swipe {
	background:#222;
	position:absolute;
	bottom:0;
	left:0;
	right:0;
	z-index:1000;
	padding:10px;
	height:30px;
	}
	#swipe #handle {
	position:absolute;
	height:20px;
	padding:5px;
	background:#fff;
	font-weight:bold;
	border:1px solid #333;
	color:blue;
	cursor:pointer;
	-webkit-user-select: none;
	}
	.map-attribution {
	bottom: 50px;
	}
	#osm1 {
	position:absolute;
	left:10px;
	top:0px;
	z-index:99;
	}
	#osm2 {
	position:absolute;
	right:10px;
	top:0px;
	z-index:99;
	}
	</style>
	<div id='swipe'>
	<div id='handle'>drag</div>
	</div>
	<div id='map' />
	<h1 id='osm1'>.png</h1>
	<h1 id='osm2'>.bpg at -q 32 (62% ratio)</h1>
	<script>
	var map = L.map('map');
	var l0 = new L.TileLayer(
	'http://c.tile.openstreetmap.pl/osmapa.pl/{z}/{x}/{y}.png', {
	maxZoom: 18,
	attribution: 'Dane <a href="http://osm.org/">OpenStreetMap</a>',
	});
	var l1 = new L.TileLayer.BPG(
	'http://c.tile.openstreetmap.pl/osmapa.pl.bpg/{z}/{x}/{y}.bpg', {
	maxZoom: 18,
	attribution: 'Dane <a href="http://osm.org/">OpenStreetMap</a>',
	});
	map.addLayer(l0);
	map.addLayer(l1);
	map.setView(new L.LatLng(52, 21), 16);

	var handle = document.getElementById('handle'),
	dragging = false,
	divide;

	handle.onmousedown = function() { dragging = true; return false; }
	document.onmouseup = function() { dragging = false; }
	document.onmousemove = function(e) {
	if (!dragging)
	return;
	setDivide(map.mouseEventToContainerPoint(e).x);
	}

	function setDivide(x) {
	var size = map.getSize();
	divide = Math.max(40, Math.min(x, size.x - 40));
	handle.style.left = (divide - 40) + 'px';
	updateClip();
	}

	function updateClip() {
	var size = map.getSize();
	var offset = map.containerPointToLayerPoint(L.point(0, 0));
	l0.getContainer().style.clip = 'rect(' + offset.y + 'px ' +
	(offset.x + divide) + 'px ' +
	(offset.y + size.y) + 'px ' +
	offset.x + 'px)';
	l1.getContainer().style.clip = 'rect(' + offset.y + 'px ' +
	(offset.x + size.x) + 'px ' +
	(offset.y + size.y) + 'px ' +
	(offset.x + divide) + 'px)';
	}

	setDivide(400);
	map.on('move', updateClip);
	</script>
	</body>
	</html>