macrovision/scripts/mapshaper/straits.py

import json
import sys
import subprocess

config = json.load(open(sys.argv[1]))
results = []

for item in config["items"]:
    lon0 = item["lon0"]
    lat0 = item["lat0"]
    lon1 = item["lon1"]
    lat1 = item["lat1"]

    center_lat = (lat0 + lat1) / 2
    center_lon = (lon0 + lon1) / 2

    path = "../../" + config["directory"] + "/" + item["name"] + ".svg"

    CMD = """\
    mapshaper -i {7} \
    -rectangle bbox={0},{1},{2},{3} name=rect \
    -clip rect target=ne_10m_land \
    -proj crs="+proj=nsper +h=10000000 +lon_0={4} +lat_0={5}" target=ne_10m_land,rect \
    -each 'console.log(this.bounds.concat([this.area]))' target=rect \
    -o "{6}" target=ne_10m_land
    """

    prepared = CMD.format(lon0, lat0, lon1, lat1, center_lon, center_lat, path, config["shapefile"])
    print(prepared)
    result = subprocess.check_output(
        prepared,
        shell=True
    )

    data = json.loads(result.decode("utf-8"))

    height = data[3] - data[1]
    area = data[4]

    results.append([item["name"], area, height])

print(json.dumps(results))