add script to generate sample raster archive.

python/examples/create_raster_example.py

@@ -0,0 +1,40 @@
+# Generates a raster tile archive for conformance testing.
+
+from urllib.request import Request, urlopen
+from pmtiles.tile import zxy_to_tileid, tileid_to_zxy, TileType, Compression
+from pmtiles.writer import Writer
+
+acc = 0
+
+with open("stamen_toner_maxzoom3.pmtiles", "wb") as f:
+    writer = Writer(f)
+
+    for tileid in range(0, zxy_to_tileid(4, 0, 0)):
+        acc += 1
+        z, x, y = tileid_to_zxy(tileid)
+        req = Request(f"https://stamen-tiles.a.ssl.fastly.net/toner/{z}/{x}/{y}.png")
+        req.add_header(
+            "User-Agent",
+            "Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:47.0) Gecko/20100101 Firefox/47.0",
+        )
+        with urlopen(req) as f:
+            writer.write_tile(tileid, f.read())
+
+    writer.finalize(
+        {
+            "tile_type": TileType.PNG,
+            "tile_compression": Compression.NONE,
+            "min_zoom": 0,
+            "max_zoom": 3,
+            "min_lon_e7": int(-180.0 * 10000000),
+            "min_lat_e7": int(-85.0 * 10000000),
+            "max_lon_e7": int(180.0 * 10000000),
+            "max_lat_e7": int(85.0 * 10000000),
+            "center_zoom": 0,
+            "center_lon_e7": 0,
+            "center_lat_e7": 0,
+        },
+        {
+            "attribution": 'Map tiles by <a href="http://stamen.com">Stamen Design</a>, under <a href="http://creativecommons.org/licenses/by/3.0">CC BY 3.0</a>. Data by <a href="http://openstreetmap.org">OpenStreetMap</a>, under <a href="http://www.openstreetmap.org/copyright">ODbL</a>.'
+        },
+    )