"""
.. _compare_threshold_filters_example:

Compare threshold filters
~~~~~~~~~~~~~~~~~~~~~~~~~

Multiple filters exist to exclude or highlight scalar values.
The goal of this example is to compare some of these filters to show how each can be used.
We will be differentiating them based on the input type they take,
as well as the output type they produce.
"""

import numpy as np

# sphinx_gallery_thumbnail_number = 1
import pyvista as pv
from pyvista import examples

# %%
# Volume Data to Volume Data
# ++++++++++++++++++++++++++
# Some filters generate `pyvista.Volume` out of `pyvista.Volume`. We will explore 3:
# :func:`pyvista.DataSetFilters.threshold`
# :func:`pyvista.ImageDataFilters.image_threshold`
# :func:`pyvista.ImageDataFilters.select_values`
# Note how `pyvista.DataSetFilters.threshold` keeps the dynamic
# of the image for the voxels above the value
# while image_threshold produces an all-or-nothing result.
# Note the little specks for the `select_values`.
# It is because it only selects the value (or values) that is (are) specified.
method_map = {'default': 0, 'threshold': 1, 'image_threshold': 2, 'select_values': 3}
step = -80
value = 155
outlines_mesh = pv.PolyData()
volume = pv.examples.download_carotid()
volume_outline = pv.Box(volume.bounds)
volume_outline.cell_data['method'] = np.full(
    (volume_outline.n_cells), method_map['default']
)
outlines_mesh += volume_outline
thresholded_vol = volume.threshold(value)
thresholded_vol = thresholded_vol.translate([step, 0, 0])
thresholded_vol_outline = pv.Box(thresholded_vol.bounds)
thresholded_vol_outline.cell_data['method'] = np.full(
    (thresholded_vol_outline.n_cells), method_map['threshold']
)
outlines_mesh += thresholded_vol_outline
image_thresholded_vol = volume.image_threshold(value, in_value=volume['scalars'].max())
image_thresholded_vol = image_thresholded_vol.translate([2 * step, 0, 0])
image_thresholded_vol_outline = pv.Box(image_thresholded_vol.bounds)
image_thresholded_vol_outline.cell_data['method'] = np.full(
    (image_thresholded_vol_outline.n_cells), method_map['image_threshold']
)
outlines_mesh += image_thresholded_vol_outline
select_values_vol = volume.select_values(value)
select_values_vol = select_values_vol.translate([3 * step, 0, 0])
select_values_vol_outline = pv.Box(select_values_vol.bounds)
select_values_vol_outline.cell_data['method'] = np.full(
    (select_values_vol_outline.n_cells), method_map['select_values']
)
outlines_mesh += select_values_vol_outline
pl = pv.Plotter()
pl.add_volume(volume)
pl.add_volume(thresholded_vol)
pl.add_volume(image_thresholded_vol)
pl.add_volume(select_values_vol)
outlines_mesh.set_active_scalars('method')
colored_outline_mesh, color_map = outlines_mesh.color_labels(
    output_scalars='method', return_dict=True
)
legend_map = dict(zip(method_map.keys(), color_map.values(), strict=True))
pl.add_mesh(colored_outline_mesh, style='wireframe', rgb=True, line_width=5)
pl.add_legend(legend_map)
cpos = pv.CameraPosition(
    position=(20, -390, -100.0), focal_point=(20, 100.0, 20.0), viewup=(0, 0, -1)
)
pl.camera_position = cpos
pl.show()
# %%
# Volume Data to Unstructured Grid
# ++++++++++++++++++++++++++++++++
# Some filters generate a `pyvista.UnstructuredGrid`
# out of a`pyvista.Volume`.
# We will explore 3:
# :func:`pyvista.DataSetFilters.threshold`
# :func:`pyvista.DataSetFilters.extract_values`
# :func:`pyvista.DataSetFilters.clip_scalar`
# Note the shape of the produced meshes.
# `clip_scalar` produces `pyvista.CellType.WEDGE`
# and `pyvista.CellType.TETRA`
# while `extract_values` and `threshold`
# produces `pyvista.CellType.VOXEL`.

method_map = {'threshold': 0, 'extract_values': 1, 'clip_scalar': 2}
volume = pv.examples.download_carotid()
step = -80
values = (155, 580)
mesh = pv.UnstructuredGrid()
pl = pv.Plotter()
clipped_vol = volume.clip_scalar(value=values)
clipped_vol.cell_data['method'] = np.full(
    (clipped_vol.number_of_cells), method_map['clip_scalar']
)
mesh += clipped_vol
extracted_values_vol = volume.extract_values(values)
extracted_values_vol.cell_data['method'] = np.full(
    (extracted_values_vol.number_of_cells), method_map['extract_values']
)
extracted_values_vol.points[:, 0] += step
mesh += extracted_values_vol

thresholded_vol = volume.threshold(values)
thresholded_vol.cell_data['method'] = np.full(
    (thresholded_vol.number_of_cells), method_map['threshold']
)
thresholded_vol.points[:, 0] += step * 2
mesh += thresholded_vol
mesh.set_active_scalars('method')
colored_mesh, color_map = mesh.color_labels(output_scalars='method', return_dict=True)
legend_map = dict(zip(method_map.keys(), color_map.values(), strict=True))
pl.add_mesh(colored_mesh, style='wireframe', rgb=True)
pl.add_legend(legend_map)
cpos = pv.CameraPosition(
    position=(55.2, -385.3, -119.1), focal_point=(55.2, 104.7, 0.9), viewup=(0, 0, -1)
)
pl.camera_position = cpos
pl.show()
# %%
# Unstructured Grid to Unstructured Grid
# ++++++++++++++++++++++++++++++++++++++
# Some filters generate a `pyvista.UnstructuredGrid`
# out of a`pyvista.UnstructuredGrid`.
# We will explore 2:
# :func:`pyvista.DataSetFilters.threshold`
# :func:`pyvista.DataSetFilters.clip_scalar`
# Notice how threshold keeps the cells which correspond
# to the specified value range while `clip_scalar` generates
# a "clean" cut, which modifies the cells at the boundaries of
# the clip.
values = (1, 2)
step = 5
surface = examples.download_foot_bones()
method_map = {'threshold': 1, 'clip_scalar': 2}
all_filtered_meshes = pv.UnstructuredGrid()
surface.point_data['x'] = surface.points[:, 0]
surface.set_active_scalars('x')
thresholded_surf = surface.threshold(values)
thresholded_surf.points[:, 2] += step
thresholded_surf.cell_data['method'] = np.full(
    (thresholded_surf.number_of_cells), method_map['threshold']
)
all_filtered_meshes += thresholded_surf
clipped_surf = surface.clip_scalar(value=values)
clipped_surf.points[:, 2] += 2 * step
clipped_surf.cell_data['method'] = np.full(
    (clipped_surf.number_of_cells), method_map['clip_scalar']
)
all_filtered_meshes += clipped_surf
all_filtered_meshes.set_active_scalars('method')
colored_mesh, color_map = all_filtered_meshes.color_labels(
    output_scalars='method', return_dict=True
)
legend_map = dict(zip(method_map.keys(), color_map.values(), strict=True))
pl = pv.Plotter()
pl.add_mesh(surface, show_edges=True)
pl.add_mesh(colored_mesh, rgb=True, show_edges=True)
pl.add_legend(legend_map)
cpos = pv.CameraPosition(
    position=(6.5, 29.4, 14.9), focal_point=(-1.1, -3.9, 6.0), viewup=(0.96, -0.3, 0.1)
)
pl.camera_position = cpos
pl.show()
# %%
# .. tags:: load
