CellTypeSource

CellTypeSource [vtkTriangle](https://www.vtk.org/doc/nightly/html/classvtkTriangle.html#details)

# !/usr/bin/env python3

from dataclasses import dataclass

# noinspection PyUnresolvedReferences
import vtkmodules.vtkInteractionStyle
# noinspection PyUnresolvedReferences
import vtkmodules.vtkRenderingFreeType
# noinspection PyUnresolvedReferences
import vtkmodules.vtkRenderingOpenGL2
from vtkmodules.vtkCommonColor import (
    vtkColorSeries,
    vtkNamedColors
)
from vtkmodules.vtkCommonCore import (
    vtkIntArray,
    vtkLookupTable,
    vtkMinimalStandardRandomSequence,
    vtkPoints
)
from vtkmodules.vtkCommonDataModel import (
    VTK_CUBIC_LINE,
    VTK_HEXAHEDRON,
    VTK_LINE,
    VTK_PYRAMID,
    VTK_QUAD,
    VTK_QUADRATIC_EDGE,
    VTK_QUADRATIC_HEXAHEDRON,
    VTK_QUADRATIC_PYRAMID,
    VTK_QUADRATIC_QUAD,
    VTK_QUADRATIC_TETRA,
    VTK_QUADRATIC_TRIANGLE,
    VTK_QUADRATIC_WEDGE,
    VTK_TETRA,
    VTK_TRIANGLE,
    VTK_WEDGE,
    vtkCellTypes
)
from vtkmodules.vtkFiltersGeneral import (
    vtkShrinkFilter,
    vtkTessellatorFilter
)
from vtkmodules.vtkFiltersSources import vtkCellTypeSource
from vtkmodules.vtkInteractionWidgets import (
    vtkTextRepresentation,
    vtkTextWidget
)
from vtkmodules.vtkRenderingCore import (
    vtkActor,
    vtkDataSetMapper,
    vtkRenderWindow,
    vtkRenderWindowInteractor,
    vtkRenderer,
    vtkTextActor,
    vtkTextProperty
)


def main():
    cell_name = get_program_parameters()

    # Store the cell class names in a dictionary.
    cell_map = dict()
    cell_map[vtkCellTypes.GetClassNameFromTypeId(VTK_LINE)] = VTK_LINE
    cell_map[vtkCellTypes.GetClassNameFromTypeId(VTK_QUADRATIC_EDGE)] = VTK_QUADRATIC_EDGE
    cell_map[vtkCellTypes.GetClassNameFromTypeId(VTK_CUBIC_LINE)] = VTK_CUBIC_LINE

    cell_map[vtkCellTypes.GetClassNameFromTypeId(VTK_TRIANGLE)] = VTK_TRIANGLE
    cell_map[vtkCellTypes.GetClassNameFromTypeId(VTK_QUADRATIC_TRIANGLE)] = VTK_QUADRATIC_TRIANGLE
    cell_map[vtkCellTypes.GetClassNameFromTypeId(VTK_QUAD)] = VTK_QUAD
    cell_map[vtkCellTypes.GetClassNameFromTypeId(VTK_QUADRATIC_QUAD)] = VTK_QUADRATIC_QUAD

    cell_map[vtkCellTypes.GetClassNameFromTypeId(VTK_TETRA)] = VTK_TETRA
    cell_map[vtkCellTypes.GetClassNameFromTypeId(VTK_HEXAHEDRON)] = VTK_HEXAHEDRON
    cell_map[vtkCellTypes.GetClassNameFromTypeId(VTK_WEDGE)] = VTK_WEDGE
    cell_map[vtkCellTypes.GetClassNameFromTypeId(VTK_PYRAMID)] = VTK_PYRAMID
    cell_map[vtkCellTypes.GetClassNameFromTypeId(VTK_QUADRATIC_WEDGE)] = VTK_QUADRATIC_WEDGE
    cell_map[vtkCellTypes.GetClassNameFromTypeId(VTK_QUADRATIC_PYRAMID)] = VTK_QUADRATIC_PYRAMID
    cell_map[vtkCellTypes.GetClassNameFromTypeId(VTK_QUADRATIC_HEXAHEDRON)] = VTK_QUADRATIC_HEXAHEDRON
    cell_map[vtkCellTypes.GetClassNameFromTypeId(VTK_QUADRATIC_TETRA)] = VTK_QUADRATIC_TETRA

    if cell_name not in cell_map:
        print('Cell type ', cell_name, ' is not supported.')
        return
    text_positions = get_text_positions(cell_map.keys(),
                                        justification=TextProperty.Justification.VTK_TEXT_CENTERED,
                                        width=0.5)

    source = vtkCellTypeSource(cell_type=cell_map[cell_name])
    source.update()
    print('Cell: ', cell_name)

    original_points = source.output.GetPoints()
    points = vtkPoints(number_of_points=source.output.number_of_points)
    rng = vtkMinimalStandardRandomSequence()
    rng.seed = 5070  # for testing
    for i in range(0, points.number_of_points):
        perturbation = [0.0] * 3
        for j in range(0, 3):
            rng.Next()
            perturbation[j] = rng.GetRangeValue(-0.1, 0.1)
        current_point = [0.0] * 3
        original_points.GetPoint(i, current_point)
        points.SetPoint(i, current_point[0] + perturbation[0],
                        current_point[1] + perturbation[1],
                        current_point[2] + perturbation[2])
    source.output.SetPoints(points)

    num_cells = source.output.number_of_cells
    print('Number of cells: ', num_cells)
    id_array = vtkIntArray(number_of_tuples=num_cells)
    for i in range(0, num_cells):
        id_array.InsertTuple1(i, i + 1)
    id_array.name = 'Ids'
    source.output.cell_data.AddArray(id_array)
    source.output.cell_data.SetActiveScalars('Ids')

    shrink = vtkShrinkFilter(shrink_factor=0.8)

    tessellate = vtkTessellatorFilter(maximum_number_of_subdivisions=3)

    # Create a lookup table to map cell data to colors.
    lut = vtkLookupTable()

    color_series = vtkColorSeries()
    series_enum = color_series.BREWER_QUALITATIVE_SET3
    color_series.color_scheme = series_enum
    color_series.BuildLookupTable(lut, color_series.ORDINAL)

    # Fill in a few known colors, the rest will be generated if needed.
    colors = vtkNamedColors()

    # Create a renderer, render window, and interactor.
    renderer = vtkRenderer(background=colors.GetColor3d('Silver'))
    render_window = vtkRenderWindow(size=(640, 480), window_name='CellTypeSource')
    render_window.AddRenderer(renderer)
    render_window_interactor = vtkRenderWindowInteractor()
    render_window_interactor.render_window = render_window

    # Create a mapper and actor.
    mapper = vtkDataSetMapper(scalar_range=(0, num_cells + 1), lookup_table=lut,
                              scalar_mode=Mapper.ScalarMode.VTK_SCALAR_MODE_USE_CELL_DATA,
                              resolve_coincident_topology=Mapper.ResolveCoincidentTopology.VTK_RESOLVE_POLYGON_OFFSET)
    if (source.GetCellType() == VTK_QUADRATIC_PYRAMID or
            source.GetCellType() == VTK_QUADRATIC_WEDGE):
        source >> shrink >> mapper
    else:
        source >> shrink >> tessellate >> mapper
    actor = vtkActor(mapper=mapper)
    actor.property.edge_visibility = True
    # actor.property.line_width = 3

    text_property = vtkTextProperty(color=colors.GetColor3d('Lamp_Black'), bold=False, italic=False, shadow=False,
                                    font_size=12, justification=TextProperty.Justification.VTK_TEXT_CENTERED)

    text_actor = vtkTextActor(input=cell_name,
                              text_scale_mode=vtkTextActor.TEXT_SCALE_MODE_NONE,
                              text_property=text_property)

    # Create the text representation. Used for positioning the text actor.
    text_representation = vtkTextRepresentation(enforce_normalized_viewport_bounds=True)
    text_representation.GetPositionCoordinate().value = text_positions[cell_name]['p']
    text_representation.GetPosition2Coordinate().value = text_positions[cell_name]['p2']

    # Create the text widget, setting the default renderer and interactor.
    text_widget = vtkTextWidget(representation=text_representation, text_actor=text_actor, default_renderer=renderer,
                                interactor=render_window_interactor, selectable=False)

    # Add the actors to the scene.
    renderer.AddViewProp(text_actor)
    renderer.AddActor(actor)

    renderer.ResetCamera()
    renderer.active_camera.Azimuth(30)
    renderer.active_camera.Elevation(30)
    renderer.ResetCameraClippingRange()

    # Render and interact.
    render_window.Render()
    text_widget.On()
    render_window_interactor.Start()


def get_text_positions(names, justification=0, vertical_justification=0, width=0.96, height=0.1):
    """
    Get viewport positioning information for a list of names.

    :param names: The list of names.
    :param justification: Horizontal justification of the text, default is left.
    :param vertical_justification: Vertical justification of the text, default is bottom.
    :param width: Width of the bounding_box of the text in screen coordinates.
    :param height: Height of the bounding_box of the text in screen coordinates.
    :return: A list of positioning information.
    """
    # The gap between the left or right edge of the screen and the text.
    dx = 0.02
    width = abs(width)
    if width > 0.96:
        width = 0.96

    y0 = 0.01
    height = abs(height)
    if height > 0.9:
        height = 0.9
    dy = height
    if vertical_justification == TextProperty.VerticalJustification.VTK_TEXT_TOP:
        y0 = 1.0 - (dy + y0)
        dy = height
    if vertical_justification == TextProperty.VerticalJustification.VTK_TEXT_CENTERED:
        y0 = 0.5 - (dy / 2.0 + y0)
        dy = height

    name_len_min = 0
    name_len_max = 0
    first = True
    for k in names:
        sz = len(k)
        if first:
            name_len_min = name_len_max = sz
            first = False
        else:
            name_len_min = min(name_len_min, sz)
            name_len_max = max(name_len_max, sz)
    text_positions = dict()
    for k in names:
        sz = len(k)
        delta_sz = width * sz / name_len_max
        if delta_sz > width:
            delta_sz = width

        if justification == TextProperty.Justification.VTK_TEXT_CENTERED:
            x0 = 0.5 - delta_sz / 2.0
        elif justification == TextProperty.Justification.VTK_TEXT_RIGHT:
            x0 = 1.0 - dx - delta_sz
        else:
            # Default is left justification.
            x0 = dx

        # For debugging!
        # print(
        #     f'{k:16s}: (x0, y0) = ({x0:3.2f}, {y0:3.2f}), (x1, y1) = ({x0 + delta_sz:3.2f}, {y0 + dy:3.2f})'
        #     f', width={delta_sz:3.2f}, height={dy:3.2f}')
        text_positions[k] = {'p': [x0, y0, 0], 'p2': [delta_sz, dy, 0]}

    return text_positions


def get_program_parameters():
    import argparse
    description = 'Cell Type Source.'
    epilogue = '''
    You can supply an optional argument consisting of a vtkCell name e.g: vtkTriangle.
    The default is vtkTetra.
    '''
    parser = argparse.ArgumentParser(description=description, epilog=epilogue,
                                     formatter_class=argparse.RawDescriptionHelpFormatter)
    parser.add_argument('cell_name', nargs='?', const='vtkTetra', default='vtkTetra', type=str, help='The cell name.')
    args = parser.parse_args()
    return args.cell_name


@dataclass(frozen=True)
class Mapper:
    @dataclass(frozen=True)
    class ColorMode:
        VTK_COLOR_MODE_DEFAULT: int = 0
        VTK_COLOR_MODE_MAP_SCALARS: int = 1
        VTK_COLOR_MODE_DIRECT_SCALARS: int = 2

    @dataclass(frozen=True)
    class ResolveCoincidentTopology:
        VTK_RESOLVE_OFF: int = 0
        VTK_RESOLVE_POLYGON_OFFSET: int = 1
        VTK_RESOLVE_SHIFT_ZBUFFER: int = 2

    @dataclass(frozen=True)
    class ScalarMode:
        VTK_SCALAR_MODE_DEFAULT: int = 0
        VTK_SCALAR_MODE_USE_POINT_DATA: int = 1
        VTK_SCALAR_MODE_USE_CELL_DATA: int = 2
        VTK_SCALAR_MODE_USE_POINT_FIELD_DATA: int = 3
        VTK_SCALAR_MODE_USE_CELL_FIELD_DATA: int = 4
        VTK_SCALAR_MODE_USE_FIELD_DATA: int = 5


@dataclass(frozen=True)
class TextProperty:
    @dataclass(frozen=True)
    class Justification:
        VTK_TEXT_LEFT: int = 0
        VTK_TEXT_CENTERED: int = 1
        VTK_TEXT_RIGHT: int = 2

    @dataclass(frozen=True)
    class VerticalJustification:
        VTK_TEXT_BOTTOM: int = 0
        VTK_TEXT_CENTERED: int = 1
        VTK_TEXT_TOP: int = 2


if __name__ == '__main__':
    main()