1 files changed, 35 insertions, 0 deletions
diff --git a/media/jslib/CaveView/lib/BGS.js b/media/jslib/CaveView/lib/BGS.js
new file mode 100644
index 0000000..f10a0ab
--- /dev/null
+++ b/media/jslib/CaveView/lib/BGS.js
@@ -0,0 +1,35 @@
+
+function BGSTileURL ( x, y, z ) {
+
+	var earthRadius = 6378137; // in meters
+
+	var tileCount = Math.pow( 2, z );
+	var tileSize = earthRadius * 2 * Math.PI / tileCount;
+
+	var x1, x2, y1, y2;
+
+	x = x - tileCount / 2;
+	y = tileCount / 2 - y;
+
+	x1 = x * tileSize;
+	y1 = y * tileSize;
+
+	x2 = x1 + tileSize;
+	y2 = y1 + tileSize;
+
+
+	var url = 'https://map.bgs.ac.uk/arcgis/services/BGS_Detailed_Geology/MapServer/WMSServer?REQUEST=GetMap&VERSION=1.3.0&LAYERS=BGS.50k.Bedrock&STYLES=default&FORMAT=image/png&CRS=EPSG:3857&WIDTH=450&HEIGHT=450';
+	var bbox = '&BBOX=' + x1 + ',' + y1 + ',' + x2 + ',' + y2;
+
+	console.log( 'BGS: ', bbox );
+
+//	var img = document.createElement( 'img' );
+
+//	img.src = url + bbox;
+//	img.crossOrigin = '';
+
+//	document.body.appendChild( img );
+
+	return url + bbox;
+
+}
+\ No newline at end of file