Source code for jupedsim.geometry_utils
# Copyright © 2012-2023 Forschungszentrum Jülich GmbH
# SPDX-License-Identifier: LGPL-3.0-or-later
from typing import Any, List, Optional, Tuple
import shapely
import jupedsim.native as py_jps
from jupedsim.geometry import Geometry
[docs]class GeometryError(Exception):
"""Class reflecting errors when creating JuPedSim geometry objects."""
def __init__(self, message) -> None:
"""Create GeometryError with the given message.
Args:
message: Error message
"""
self.message = message
def _geometry_from_wkt(wkt_input: str) -> Geometry:
geometry_collection = None
try:
wkt_type = shapely.from_wkt(wkt_input)
except Exception as exc:
raise GeometryError(
f"Could not create geometry objects from the given WKT: "
f"{wkt_input}. See following error message:\n{exc}"
) from exc
if isinstance(wkt_type, shapely.GeometryCollection):
geometry_collection = wkt_type
else:
try:
geometry_collection = shapely.GeometryCollection([wkt_type])
except Exception as exc:
raise GeometryError(
f"Could not create a geometry collection from the given WKT: "
f"{wkt_input}. See following error message:\n{exc}"
) from exc
polygons = _polygons_from_geometry_collection(geometry_collection)
return Geometry(_internal_build_geometry(polygons))
def _geometry_from_shapely(
geometry_input: shapely.Polygon
| shapely.MultiPolygon
| shapely.GeometryCollection
| shapely.MultiPoint,
) -> Geometry:
polygons = _polygons_from_geometry_collection(
shapely.GeometryCollection([geometry_input])
)
return Geometry(_internal_build_geometry(polygons))
def _geometry_from_coordinates(
coordinates: List[Tuple], *, excluded_areas: Optional[List[Tuple]] = None
) -> Geometry:
polygon = shapely.Polygon(coordinates, holes=excluded_areas)
return Geometry(_internal_build_geometry([polygon]))
def _polygons_from_geometry_collection(
geometry_collection: shapely.GeometryCollection,
) -> List[shapely.Polygon]:
def _polygons_from_multi_polygon(
multi_polygon: shapely.MultiPolygon,
) -> List[shapely.Polygon]:
result = []
for polygon in multi_polygon.geoms:
result += _polygons_from_polygon(polygon)
return result
def _polygons_from_linear_ring(
linear_ring: shapely.LinearRing,
) -> List[shapely.Polygon]:
return _polygons_from_polygon(shapely.Polygon(linear_ring))
def _polygons_from_polygon(
polygon: shapely.Polygon,
) -> List[shapely.Polygon]:
return [polygon]
polygons = []
for geo in geometry_collection.geoms:
if shapely.get_type_id(geo) == shapely.GeometryType.GEOMETRYCOLLECTION:
polygons += _polygons_from_geometry_collection(geo)
elif shapely.get_type_id(geo) == shapely.GeometryType.MULTIPOLYGON:
polygons += _polygons_from_multi_polygon(geo)
elif shapely.get_type_id(geo) == shapely.GeometryType.LINEARRING:
polygons += _polygons_from_linear_ring(geo)
elif shapely.get_type_id(geo) == shapely.GeometryType.POLYGON:
polygons += _polygons_from_polygon(geo)
else:
raise GeometryError(
f"Unexpected geometry type found in GeometryCollection: "
f"{geo.geom_type}. Only Polygon types are allowed."
)
return polygons
def _internal_build_geometry(
polygons: List[shapely.Polygon],
) -> py_jps.Geometry:
geo_builder = py_jps.GeometryBuilder()
for polygon in polygons:
geo_builder.add_accessible_area(polygon.exterior.coords[:-1])
for hole in polygon.interiors:
geo_builder.exclude_from_accessible_area(hole.coords[:-1])
return geo_builder.build()
[docs]def build_geometry(
geometry: list[tuple[float, float]]
| shapely.GeometryCollection
| shapely.Polygon
| shapely.MultiPolygon
| shapely.MultiPoint
| str,
**kwargs: Any,
) -> Geometry:
"""Create a :class:`~jupedsim.geometry.Geometry` from different input representations.
.. note ::
The geometric data supplied need to form a single "simple" polygon with holes. In case
the input contains multiple polygons this must hold true for the union of all polygons.
Arguments:
geometry: Data to create the geometry out of. Data may be supplied as:
* list of 2d points describing the outer boundary, holes may be added with use of `excluded_areas` kw-argument
* :class:`~shapely.GeometryCollection` consisting only out of :class:`Polygons <shapely.Polygon>`, :class:`MultiPolygons <shapely.MultiPolygon>` and :class:`MultiPoints <shapely.MultiPoint>`
* :class:`~shapely.MultiPolygon`
* :class:`~shapely.Polygon`
* :class:`~shapely.MultiPoint` forming a "simple" polygon when points are interpreted as linear ring without repetition of the start/end point.
* str with a valid Well Known Text. In this format the same WKT types as mentioned for the shapely types are supported: GEOMETRYCOLLETION, MULTIPOLYGON, POLYGON, MULTIPOINT. The same restrictions as mentioned for the shapely types apply.
Keyword Arguments:
excluded_areas: describes exclusions
from the walkable area. Only use this argument if `geometry` was
provided as list[tuple[float, float]].
"""
if isinstance(geometry, str):
return _geometry_from_wkt(geometry)
elif (
isinstance(geometry, shapely.GeometryCollection)
or isinstance(geometry, shapely.Polygon)
or isinstance(geometry, shapely.MultiPolygon)
or isinstance(geometry, shapely.MultiPoint)
):
return _geometry_from_shapely(geometry)
else:
return _geometry_from_coordinates(
geometry, excluded_areas=kwargs.get("excluded_areas")
)