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sudo apt get update sudo apt get upgrade sudo apt install python3-pip pip install rio-rgbify PATH="$PATH:/home/<user /.local/bin" # The following two steps are only necessary when mounting an external hard drive or USB flash drive: sudo mkdir /mnt/f sudo mount -t drvfs D: /mnt/f rio rgbify -b -10000 -i 0.1 wa_1arc_v3_merged_3857.tif wa_1arc_v3_merged_3857_rgb.tif # The following steps are only necessary when unmounting an external hard drive or USB flash drive: cd \~ sudo umount /mnt/f/

import logging from wsgiref import headers import azure.functions as func import psycopg2 # Database to connect to DATABASE = { 'user': 'postgres', 'password': '{password}', 'host': 'localhost', 'port': '5432', 'database': '{database}' } def main(req: func.HttpRequest) -> func.HttpResponse: logging.info('Python HTTP trigger function processed a request.') DATABASE_CONNECTION = None # get url parameters http://localhost:7071/api/tileserver?zoom={z}&x={x}&y={y} # http://localhost:7071/api/tileserver?zoom=16&x=10556&y=22870 zoom = int(req.params.get('zoom')) x = int(req.params.get('x')) y = int(req.params.get('y')) table = req.params.get('table') # calculate the envelope of the tile # Width of world in EPSG:3857 worldMercMax = 20037508.3427892 worldMercMin = -1 * worldMercMax worldMercSize = worldMercMax - worldMercMin # Width in tiles worldTileSize = 2 ** zoom # Tile width in EPSG:3857 tileMercSize = worldMercSize / worldTileSize # Calculate geographic bounds from tile coordinates # XYZ tile coordinates are in "image space" so origin is # top-left, not bottom right xmin = worldMercMin + tileMercSize * x xmax = worldMercMin + tileMercSize * (x + 1) ymin = worldMercMax - tileMercSize * (y + 1) ymax = worldMercMax - tileMercSize * y # Generate SQL to materialize a query envelope in EPSG:3857. # Densify the edges a little so the envelope can be # safely converted to other coordinate systems. DENSIFY_FACTOR = 4 segSize = (xmax - xmin)/DENSIFY_FACTOR sql01 = 'ST_Segmentize(ST_MakeEnvelope(' + str(xmin) + ', ' + str(ymin) + ', ' + str(xmax) + ', ' + str(ymax) + ', 3857), ' + str(segSize) +')' # Generate a SQL query to pull a tile worth of MVT data # from the table of interest. # Materialize the bounds # Select the relevant geometry and clip to MVT bounds # Convert to MVT format sql02 = 'WITH bounds AS (SELECT ' + sql01 + ' AS geom, ' + sql01 + '::box2d AS b2d), mvtgeom AS (SELECT ST_AsMVTGeom(ST_Transform(t.geom, 3857), bounds.b2d) AS geom, elev FROM contourlines_smooth t, bounds WHERE ST_Intersects(t.geom, ST_Transform(bounds.geom, 4326))) SELECT ST_AsMVT(mvtgeom.*) FROM mvtgeom' # Run tile query SQL and return error on failure conditions # Make and hold connection to database if not DATABASE_CONNECTION: try: DATABASE_CONNECTION = psycopg2.connect(**DATABASE) logging.info('Connected to database.') except (Exception, psycopg2.Error) as error: logging.error('ERROR: Cannot connect to database.') # Query for MVT with DATABASE_CONNECTION.cursor() as cur: cur.execute(sql02) if not cur: logging.error('ERROR: SQL Query failed.') pbf = cur.fetchone()[0] logging.info('Queried database') if zoom and x and y: return func.HttpResponse( # f"This HTTP triggered function executed successfully.\n\nzoom={zoom}\nx={x}\ny={y}\n\nxmin={xmin}\nxmax={xmax}\nymin={ymin}\nymax={ymax}\n\nsql01={sql01}\n\nsql02={sql02}", bytes(pbf), status_code=200, headers={"Content-type": "application/vnd.mapbox-vector-tile","Access-Control-Allow-Origin": "*"} ) else: return func.HttpResponse( "ERROR: Missing parameter!", status_code=400 )