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billinglayer/python/shapely/_pygeos_api.pxd

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+"""
+Provides a wrapper for the shapely.lib C API for use in Cython.
+Internally, the shapely C extension uses a PyCapsule to provide run-time access
+to function pointers within the C API.
+
+To use these functions, you must first call the following function in each Cython module:
+`import_shapely_c_api()`
+
+This uses a macro to dynamically load the functions from pointers in the PyCapsule.
+Each C function in shapely.lib exposed in the C API must be specially-wrapped to enable
+this capability.
+
+Segfaults will occur if the C API is not imported properly.
+"""
+
+cimport numpy as np
+from cpython.ref cimport PyObject
+
+from shapely._geos cimport GEOSContextHandle_t, GEOSCoordSequence, GEOSGeometry
+
+
+cdef extern from "c_api.h":
+    # shapely.lib C API loader; returns -1 on error
+    # MUST be called before calling other C API functions
+    int import_shapely_c_api() except -1
+
+    # C functions provided by the shapely.lib C API
+    # Note: GeometryObjects are always managed as Python objects
+    # in Cython to avoid memory leaks, not PyObject* (even though
+    # they are declared that way in the header file).
+    object PyGEOS_CreateGeometry(GEOSGeometry *ptr, GEOSContextHandle_t ctx)
+    char PyGEOS_GetGEOSGeometry(PyObject *obj, GEOSGeometry **out) nogil
+    GEOSCoordSequence* PyGEOS_CoordSeq_FromBuffer(GEOSContextHandle_t ctx, const double* buf,
+                                                 unsigned int size, unsigned int dims,
+                                                 char ring_closure) nogil