58 lines
1.8 KiB
Python
58 lines
1.8 KiB
Python
import json
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import sys
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import os
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def write_polygon(f, coords):
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"""Write a single polygon ring to the poly file."""
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# Close polygon if not already closed
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if coords[0] != coords[-1]:
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coords.append(coords[0])
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for lon, lat in coords:
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f.write(f" {lon} {lat}\n")
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f.write("END\n")
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def geojson_to_poly(geojson_file):
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base_name = os.path.splitext(os.path.basename(geojson_file))[0]
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poly_file = f"{base_name}.poly"
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with open(geojson_file, 'r', encoding='utf-8') as f:
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data = json.load(f)
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with open(poly_file, 'w', encoding='utf-8') as f:
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f.write(f"{base_name}\n")
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feature_index = 1
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for feature in data["features"]:
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geom_type = feature["geometry"]["type"]
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coords = feature["geometry"]["coordinates"]
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if geom_type == "Polygon":
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# Handle flat array: [ [lon, lat], ... ]
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if isinstance(coords[0][0], float):
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coords = [coords]
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for ring in coords:
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f.write(f"{feature_index}\n")
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write_polygon(f, ring)
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feature_index += 1
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elif geom_type == "MultiPolygon":
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for poly in coords:
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# Each poly is [ [ [lon, lat], ... ] ]
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ring = poly[0] # use outer ring only
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f.write(f"{feature_index}\n")
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write_polygon(f, ring)
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feature_index += 1
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else:
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print(f"Skipping unsupported geometry type: {geom_type}")
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f.write("END\n")
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print(f"Created .poly file: {poly_file}")
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if __name__ == "__main__":
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if len(sys.argv) < 2:
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print("Usage: python geojson_to_poly.py <geojson_file>")
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sys.exit(1)
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geojson_file = sys.argv[1]
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geojson_to_poly(geojson_file) |