Add natural earth to mbtiles example

Author: jericks

examples/naturalearth2mbtiles.groovy

@@ -0,0 +1,42 @@
+import geoscript.layer.ImageTileRenderer
+import geoscript.layer.Layer
+import geoscript.layer.MBTiles
+import geoscript.layer.Pyramid
+import geoscript.layer.TileGenerator
+import geoscript.layer.TileRenderer
+import geoscript.style.Fill
+import geoscript.style.Stroke
+import geoscript.workspace.Directory
+import geoscript.workspace.GeoPackage
+
+import static geoscript.GeoScript.download
+import static geoscript.GeoScript.unzip
+
+// Download data from natural earth
+File dataDir = new File("naturalearth")
+[
+        [name: "countries", url: "http://www.naturalearthdata.com/http//www.naturalearthdata.com/download/110m/cultural/ne_110m_admin_0_countries.zip"],
+        [name: "ocean",     url: "http://www.naturalearthdata.com/http//www.naturalearthdata.com/download/110m/physical/ne_110m_ocean.zip"],
+        [name: "places",    url: "http://www.naturalearthdata.com/http//www.naturalearthdata.com/download/110m/cultural/ne_110m_populated_places.zip"],
+        [name: "rivers",    url: "http://www.naturalearthdata.com/http//www.naturalearthdata.com/download/110m/physical/ne_110m_rivers_lake_centerlines.zip"],
+        [name: "states",    url: "http://www.naturalearthdata.com/http//www.naturalearthdata.com/download/110m/cultural/ne_110m_admin_1_states_provinces.zip"]
+
+].each { Map item ->
+    println "Downloading ${item.name} from ${item.url}..."
+    unzip(download(new URL(item.url), new File(dataDir, "${item.name}.zip"), overwrite: false))
+}
+
+Directory directory = new Directory("naturalearth")
+Layer countries = directory.get("ne_110m_admin_0_countries")
+countries.style = new Fill("#ffffff") + new Stroke("#b2b2b2", 0.5)
+Layer ocean = directory.get("ne_110m_ocean")
+ocean.style = new Fill("#a5bfdd")
+
+File mbtilesFile = new File("world.mbtiles")
+if (mbtilesFile.exists()) {
+    mbtilesFile.delete()
+}
+TileGenerator generator = new TileGenerator(verbose: true)
+MBTiles mbtiles = new MBTiles(mbtilesFile, "World", "Natural Earth")
+ImageTileRenderer renderer = new ImageTileRenderer(mbtiles, [ocean, countries])
+generator.generate(mbtiles, renderer, 0, 3)