# Examples from pyvista.DataSet.cell_neighbors
# ============================================

from pyvista import examples
mesh = examples.load_airplane()

# Get the neighbor cell ids that have at least one point in common with
# the 0-th cell.
mesh.cell_neighbors(0, 'points')

# Get the neighbor cell ids that have at least one edge in common with
# the 0-th cell.
mesh.cell_neighbors(0, 'edges')

# For unstructured grids with cells of dimension 3 (Tetrahedron for example),
# cell neighbors can be defined using faces.
mesh = examples.download_tetrahedron()
mesh.cell_neighbors(0, 'faces')

# Show a visual example.
from functools import partial
import pyvista as pv
mesh = pv.Sphere(theta_resolution=10)

pl = pv.Plotter(shape=(1, 2))
pl.link_views()
add_point_labels = partial(
    pl.add_point_labels,
    text_color='white',
    font_size=20,
    shape=None,
    show_points=False,
)

for i, connection in enumerate(['points', 'edges']):
    pl.subplot(0, i)
    pl.view_xy()
    _ = pl.add_title(
        f'{connection.capitalize()} neighbors',
        color='red',
        shadow=True,
        font_size=8,
    )

    # Add current cell
    i_cell = 0
    current_cell = mesh.extract_cells(i_cell)
    _ = pl.add_mesh(current_cell, show_edges=True, color='blue')
    _ = add_point_labels(
        current_cell.cell_centers().points,
        labels=[f'{i_cell}'],
    )

    # Add neighbors
    ids = mesh.cell_neighbors(i_cell, connection)
    cells = mesh.extract_cells(ids)
    _ = pl.add_mesh(cells, color='red', show_edges=True)
    _ = add_point_labels(
        cells.cell_centers().points,
        labels=[f'{i}' for i in ids],
    )

    # Add other cells
    ids.append(i_cell)
    others = mesh.extract_cells(ids, invert=True)
    _ = pl.add_mesh(others, show_edges=True)
pl.show()

# ----------------------------------------------------------------------
# Generated by sphinx-examples-as-code https://github.com/pyvista/sphinx-examples-as-code