Function PyArray_NeighborhoodIterNew

numpy/core/src/multiarray/iterators.c:1703–1801

* fill and x->ao should have equivalent types */ NUMPY_API * A Neighborhood Iterator object. */

 * A Neighborhood Iterator object.
*/
NPY_NO_EXPORT PyObject*
PyArray_NeighborhoodIterNew(PyArrayIterObject *x, const npy_intp *bounds,
                            int mode, PyArrayObject* fill)
{
    int i;
    PyArrayNeighborhoodIterObject *ret;

    ret = PyArray_malloc(sizeof(*ret));
    if (ret == NULL) {
        return NULL;
    }
    PyObject_Init((PyObject *)ret, &PyArrayNeighborhoodIter_Type);

    Py_INCREF(x->ao);  /* PyArray_RawIterBaseInit steals a reference */
    PyArray_RawIterBaseInit((PyArrayIterObject*)ret, x->ao);
    Py_INCREF(x);
    ret->_internal_iter = x;

    ret->nd = PyArray_NDIM(x->ao);

    for (i = 0; i < ret->nd; ++i) {
        ret->dimensions[i] = PyArray_DIMS(x->ao)[i];
    }

    /* Compute the neighborhood size and copy the shape */
    ret->size = 1;
    for (i = 0; i < ret->nd; ++i) {
        ret->bounds[i][0] = bounds[2 * i];
        ret->bounds[i][1] = bounds[2 * i + 1];
        ret->size *= (ret->bounds[i][1] - ret->bounds[i][0]) + 1;

        /* limits keep track of valid ranges for the neighborhood: if a bound
         * of the neighborhood is outside the array, then limits is the same as
         * boundaries. On the contrary, if a bound is strictly inside the
         * array, then limits correspond to the array range. For example, for
         * an array [1, 2, 3], if bounds are [-1, 3], limits will be [-1, 3],
         * but if bounds are [1, 2], then limits will be [0, 2].
         *
         * This is used by neighborhood iterators stacked on top of this one */
        ret->limits[i][0] = ret->bounds[i][0] < 0 ? ret->bounds[i][0] : 0;
        ret->limits[i][1] = ret->bounds[i][1] >= ret->dimensions[i] - 1 ?
                            ret->bounds[i][1] :
                            ret->dimensions[i] - 1;
        ret->limits_sizes[i] = (ret->limits[i][1] - ret->limits[i][0]) + 1;
    }

    switch (mode) {
        case NPY_NEIGHBORHOOD_ITER_ZERO_PADDING:
            ret->constant = PyArray_Zero(x->ao);
            ret->mode = mode;
            ret->translate = &get_ptr_constant;
            break;
        case NPY_NEIGHBORHOOD_ITER_ONE_PADDING:
            ret->constant = PyArray_One(x->ao);
            ret->mode = mode;
            ret->translate = &get_ptr_constant;
            break;
        case NPY_NEIGHBORHOOD_ITER_CONSTANT_PADDING: