FEATURE: Add Shapely-based polygon computation backend

CONTRIBUTORS.md

@@ -17,6 +17,7 @@
 * [Kathy Pippert](https://github.com/PipKat)
 * [Maxime Rey](https://github.com/MaxJPRey)
 * [Minsi Sung](https://github.com/ansminsisung)
+* [Mohammad Zandsalimy](https://github.com/mozandsal)
 * [Roberto Pastor Muela](https://github.com/RobPasMue)
 * [SitaRamesh](https://github.com/SitaRamesh)
 * [SriniSundararajan](https://github.com/SriniSundararajan)

pyproject.toml

@@ -29,7 +29,8 @@ dependencies = [
     "protobuf>=3.19.3,<7",
     "grpcio>=1.44.0",
     "Django>=4.2.16",
-    "ansys-tools-common>=0.3.1"
+    "ansys-tools-common>=0.3.1",
+    "shapely==2.1.2"
 ]
 
 [project.urls]

src/ansys/edb/core/config.py

@@ -0,0 +1,80 @@
+"""Configuration management for pyedb-core."""
+from enum import Enum
+import os
+
+
+class ComputationBackend(Enum):
+    """Computation backend options for geometry operations."""
+
+    SERVER = "server"  # Use RPC server
+    SHAPELY = "shapely"  # Use Shapely library
+    AUTO = "auto"  # Auto-select: prefer server
+
+
+class Config:
+    """Global configuration for pyedb-core.
+
+    Configuration can be set via environment variables or programmatically.
+    CAUTION: if you are setting the backend programmatically by calling
+    ``Config.set_computation_backend()``, the ``Config.reset()`` method is called
+    automatically to clear any previous settings. However, if you set the backend
+    via the environment variable ``PYEDB_COMPUTATION_BACKEND``, you need to call
+    ``Config.reset()`` manually to ensure the new setting is applied.
+
+    Environment Variables:
+        PYEDB_COMPUTATION_BACKEND: Set to 'server', 'shapely', or 'auto' (default: 'auto')
+
+    Examples:
+        >>> # Set via environment variable (before importing)
+        >>> import os
+        >>> Config.reset()  # Clear previous settings
+        >>> os.environ['PYEDB_COMPUTATION_BACKEND'] = 'shapely'
+
+        >>> # Set programmatically
+        >>> from ansys.edb.core.config import Config, ComputationBackend
+        >>> Config.set_computation_backend(ComputationBackend.SHAPELY)
+    """
+
+    _computation_backend: ComputationBackend = None
+
+    @classmethod
+    def get_computation_backend(cls) -> ComputationBackend:
+        """Get the current computation backend setting.
+
+        Returns
+        -------
+        ComputationBackend
+            The configured computation backend.
+        """
+        if cls._computation_backend is None:
+            env_value = os.getenv("PYEDB_COMPUTATION_BACKEND", "auto").lower()
+            try:
+                cls._computation_backend = ComputationBackend(env_value)
+            except ValueError:
+                cls._computation_backend = ComputationBackend.AUTO
+
+        return cls._computation_backend
+
+    @classmethod
+    def set_computation_backend(cls, backend: ComputationBackend | str):
+        """Set the computation backend.
+
+        Parameters
+        ----------
+        backend : ComputationBackend or str
+            The backend to use for geometry computations.
+            Can be 'server', 'shapely', or 'auto'.
+
+        Examples:
+            >>> Config.set_computation_backend(ComputationBackend.SHAPELY)
+            >>> Config.set_computation_backend('shapely')
+        """
+        cls.reset()
+        if isinstance(backend, str):
+            backend = ComputationBackend(backend.lower())
+        cls._computation_backend = backend
+
+    @classmethod
+    def reset(cls):
+        """Reset configuration to defaults (useful for testing)."""
+        cls._computation_backend = None

src/ansys/edb/core/geometry/backends/__init__.py

@@ -0,0 +1,6 @@
+"""Geometry computation backends."""
+
+from ansys.edb.core.geometry.backends.backend_factory import get_backend
+from ansys.edb.core.geometry.backends.base import PolygonBackend
+
+__all__ = ["PolygonBackend", "get_backend"]

src/ansys/edb/core/geometry/backends/backend_factory.py

@@ -0,0 +1,101 @@
+"""Factory for creating the appropriate polygon computation backend."""
+
+from __future__ import annotations
+
+from ansys.edb.core.config import ComputationBackend, Config
+from ansys.edb.core.geometry.backends.base import PolygonBackend
+
+
+def get_backend(stub=None) -> PolygonBackend:
+    """Get the appropriate polygon computation backend based on configuration.
+
+    Parameters
+    ----------
+    stub : polygon_data_pb2_grpc.PolygonDataServiceStub, optional
+        The gRPC stub for polygon operations. Required for server backend.
+
+    Returns
+    -------
+    PolygonBackend
+        The configured computation backend.
+
+    Notes
+    -----
+    The backend is selected based on the PYEDB_COMPUTATION_BACKEND environment
+    variable or the programmatic configuration. The selection logic is:
+
+    - 'server': Always use server backend
+    - 'shapely': Use Shapely backend (raises error if not installed)
+    - 'auto' (default): Try Shapely first, fallback to server if not available
+
+    Examples
+    --------
+    >>> # Use server backend explicitly
+    >>> import os
+    >>> os.environ['PYEDB_COMPUTATION_BACKEND'] = 'server'
+    >>> backend = get_backend(stub)
+
+    >>> # Use Shapely backend
+    >>> from ansys.edb.core.config import Config, ComputationBackend
+    >>> Config.set_computation_backend(ComputationBackend.SHAPELY)
+    >>> backend = get_backend()
+    """
+    backend_type = Config.get_computation_backend()
+
+    if backend_type == ComputationBackend.SERVER:
+        return _get_server_backend(stub)
+
+    elif backend_type == ComputationBackend.SHAPELY:
+        return _get_shapely_backend(stub)
+
+    elif backend_type == ComputationBackend.AUTO:
+        # Use server backend by default
+        return _get_server_backend(stub)
+
+    else:
+        raise ValueError(f"Unknown backend type: {backend_type}")
+
+
+def _get_server_backend(stub) -> PolygonBackend:
+    """Get the server backend instance.
+
+    Parameters
+    ----------
+    stub : polygon_data_pb2_grpc.PolygonDataServiceStub
+        The gRPC stub for polygon operations.
+
+    Returns
+    -------
+    ServerBackend
+        Server computation backend.
+    """
+    if stub is None:
+        raise ValueError("Server backend requires a stub parameter")
+
+    from ansys.edb.core.geometry.backends.server_backend import ServerBackend
+
+    return ServerBackend(stub)
+
+
+def _get_shapely_backend(stub=None) -> PolygonBackend:
+    """Get the Shapely backend instance.
+
+    Parameters
+    ----------
+    stub : polygon_data_pb2_grpc.PolygonDataServiceStub, optional
+        The gRPC stub for polygon operations. Passed to ShapelyBackend for
+        methods that delegate to the server backend (e.g., alpha_shape).
+
+    Returns
+    -------
+    ShapelyBackend
+        Shapely computation backend.
+
+    Raises
+    ------
+    ImportError
+        If Shapely is not installed.
+    """
+    from ansys.edb.core.geometry.backends.shapely_backend import ShapelyBackend
+
+    return ShapelyBackend(stub)