switch to 30m resolution

Author: Vincent van der Wal

src/main.ts

@@ -210,10 +210,10 @@ if (mapContainer) {
 		map.addSource('rasterDem', {
 			type: 'raster-dem',
 			tiles: [
-				'https://mbtiles.servert.nl/services/copernicus-90m-terrain/tiles/{z}/{x}/{y}.png'
+				'https://mbtiles.servert.nl/services/copernicus-30m-terrain/tiles/{z}/{x}/{y}.png'
 			],
 			tileSize: 256,
-			maxzoom: 10
+			maxzoom: 11
 		});
 
 		map.addLayer(

src/worker.ts

@@ -142,8 +142,6 @@ const drawIcon = (
 		const lat = tile2lat(y + iCenter / TILE_SIZE, z);
 		const lon = tile2lon(x + jCenter / TILE_SIZE, z);
 
-		let indCenter = jCenter + iCenter * TILE_SIZE;
-
 		const { index, xFraction, yFraction } = getIndexAndFractions(
 			lat,
 			lon,