Adding LineWidget2

src/Cxx/Widgets/LineWidget2.cxx

@@ -29,15 +29,18 @@ public:
 
     vtkLineWidget2* lineWidget = reinterpret_cast<vtkLineWidget2*>(caller);
 
-    // Get the actual box coordinates of the line
+    vtkLineRepresentation* rep =
+        static_cast<vtkLineRepresentation*>(lineWidget->GetRepresentation());
     vtkNew<vtkPolyData> polydata;
-    static_cast<vtkLineRepresentation*>(lineWidget->GetRepresentation())
-        ->GetPolyData(polydata);
+    rep->GetPolyData(polydata);
 
-    // Display one of the points, just so we know it's working
+    // Get the actual box coordinates of the line.
     double p[3];
     polydata->GetPoint(0, p);
-    std::cout << "P: " << p[0] << " " << p[1] << " " << p[2] << std::endl;
+    std::cout << "P1: " << p[0] << " " << p[1] << " " << p[2] << std::endl;
+    polydata->GetPoint(1, p);
+    std::cout << "P2: " << p[0] << " " << p[1] << " " << p[2] << std::endl;
+    std::cout << "Distance: " << rep->GetDistance() << std::endl;
   }
   vtkLineCallback()
   {
@@ -50,35 +53,38 @@ int main(int, char*[])
   vtkNew<vtkNamedColors> colors;
 
   vtkNew<vtkSphereSource> sphereSource;
-  sphereSource->Update();
 
-  // Create a mapper and actor
+  // Create a mapper and actor.
   vtkNew<vtkPolyDataMapper> mapper;
   mapper->SetInputConnection(sphereSource->GetOutputPort());
   vtkNew<vtkActor> actor;
   actor->SetMapper(mapper);
   actor->GetProperty()->SetColor(colors->GetColor3d("MistyRose").GetData());
 
-  // A renderer and render window
+  // A renderer, render window and interactor.
   vtkNew<vtkRenderer> renderer;
   vtkNew<vtkRenderWindow> renderWindow;
   renderWindow->AddRenderer(renderer);
   renderWindow->SetWindowName("LineWidget2");
+  vtkNew<vtkRenderWindowInteractor> renderWindowInteractor;
+  renderWindowInteractor->SetRenderWindow(renderWindow);
 
   renderer->AddActor(actor);
   renderer->SetBackground(colors->GetColor3d("MidnightBlue").GetData());
 
-  // An interactor
-  vtkNew<vtkRenderWindowInteractor> renderWindowInteractor;
-  renderWindowInteractor->SetRenderWindow(renderWindow);
-
   vtkNew<vtkLineWidget2> lineWidget;
   lineWidget->SetInteractor(renderWindowInteractor);
   lineWidget->CreateDefaultRepresentation();
 
   // You could do this if you want to set properties at this point:
-  // vtkNew<vtkLineRepresentation> lineRepresentation;
-  // lineWidget->SetRepresentation(lineRepresentation);
+  vtkNew<vtkLineRepresentation> lineRepresentation;
+  lineRepresentation->GetLineProperty()->SetColor(
+      colors->GetColor3d("Yellow").GetData());
+  lineRepresentation->GetEndPointProperty()->SetColor(
+      colors->GetColor3d("Magenta").GetData());
+  lineRepresentation->GetEndPoint2Property()->SetColor(
+      colors->GetColor3d("Magenta").GetData());
+  lineWidget->SetRepresentation(lineRepresentation);
 
   vtkNew<vtkLineCallback> lineCallback;
 
@@ -91,7 +97,7 @@ int main(int, char*[])
   renderWindow->Render();
   lineWidget->On();
 
-  // Begin mouse interaction
+  // Begin the mouse interaction.
   renderWindowInteractor->Start();
 
   return EXIT_SUCCESS;

src/PythonicAPI.md

@@ -707,6 +707,7 @@ See [this tutorial](http://www.vtk.org/Wiki/VTK/Tutorials/3DDataTypes) for a bri
 [ImplicitAnnulusWidget](/PythonicAPI/Widgets/ImplicitAnnulusWidget) | Clip polydata with an implicit annulus.
 [ImplicitConeWidget](/PythonicAPI/Widgets/ImplicitConeWidget) | An interactive implicit cone widget.
 [ImplicitPlaneWidget2](/PythonicAPI/Widgets/ImplicitPlaneWidget2) | Clip polydata with an implicit plane.
+[LineWidget2](/PythonicAPI/Widgets/LineWidget2) |
 [PolygonalSurfacePointPlacer](/PythonicAPI/PolyData/PolygonalSurfacePointPlacer) | Used in conjunction with vtkContourWidget to draw curves on a surface.
 [RectilinearWipeWidget](/PythonicAPI/Widgets/RectilinearWipeWidget) | Compare two images.
 [Slider2D](/PythonicAPI/Widgets/Slider2D) | 2D Slider.

src/PythonicAPI/Widgets/LineWidget2.py

+#!/usr/bin/env python3
+
+# noinspection PyUnresolvedReferences
+import vtkmodules.vtkInteractionStyle
+# noinspection PyUnresolvedReferences
+import vtkmodules.vtkRenderingOpenGL2
+# noinspection PyUnresolvedReferences
+import vtkmodules.vtkRenderingUI
+from vtkmodules.vtkCommonColor import vtkNamedColors
+from vtkmodules.vtkCommonDataModel import vtkPolyData
+from vtkmodules.vtkFiltersSources import vtkSphereSource
+from vtkmodules.vtkInteractionWidgets import (
+    vtkLineRepresentation,
+    vtkLineWidget2
+)
+from vtkmodules.vtkRenderingCore import (
+    vtkActor,
+    vtkPolyDataMapper,
+    vtkRenderWindow,
+    vtkRenderWindowInteractor,
+    vtkRenderer
+)
+
+
+def main():
+    colors = vtkNamedColors()
+
+    sphere_source = vtkSphereSource()
+
+    # Create a mapper and actor.
+    mapper = vtkPolyDataMapper()
+    sphere_source >> mapper
+    actor = vtkActor(mapper=mapper)
+    actor.property.color = colors.GetColor3d('MistyRose')
+
+    # A renderer, render window and interactor.
+    renderer = vtkRenderer(background=colors.GetColor3d('MidnightBlue'))
+    render_window = vtkRenderWindow(window_name='LineWidget2')
+    render_window.AddRenderer(renderer)
+    render_window_interactor = vtkRenderWindowInteractor()
+    render_window_interactor.render_window = render_window
+
+    renderer.AddActor(actor)
+
+    # The line widget.
+    line_widget = vtkLineWidget2(interactor=render_window_interactor)
+    line_widget.CreateDefaultRepresentation()
+
+    # You could do this if you want to set properties at this point:
+    line_representation = vtkLineRepresentation()
+    line_representation.line_property.SetColor(colors.GetColor3d('Yellow'))
+    line_representation.end_point_property.SetColor(colors.GetColor3d('Magenta'))
+    line_representation.end_point2_property.SetColor(colors.GetColor3d('Magenta'))
+    line_widget.SetRepresentation(line_representation)
+
+    line_callback = LineCallback()
+    line_widget.AddObserver('InteractionEvent', line_callback)
+
+    # Render
+    render_window.Render()
+    render_window_interactor.Initialize()
+    render_window.Render()
+    line_widget.On()
+
+    # Begin the mouse interaction.
+    render_window_interactor.Start()
+
+
+class LineCallback:
+
+    def __call__(self, caller, ev):
+        # This is a vtkLineWidget2 line representation.
+        rep = caller.representation
+        polydata = vtkPolyData()
+        rep.GetPolyData(polydata)
+        pt = [0] * 3
+        # Get the actual box coordinates of the line.
+        for i in range(0, 2):
+            polydata.GetPoint(i, pt)
+            print(f'Point {i}: {fmt_floats(pt)}')
+        print(f'Distance: {rep.distance:0.6g}')
+
+
+def fmt_floats(v, w=0, d=6, pt='g'):
+    """
+    Pretty print a list or tuple of floats.
+
+    :param v: The list or tuple of floats.
+    :param w: Total width of the field.
+    :param d: The number of decimal places.
+    :param pt: The presentation type, 'f', 'g' or 'e'.
+    :return: A string.
+    """
+    pt = pt.lower()
+    if pt not in ['f', 'g', 'e']:
+        pt = 'f'
+    return ', '.join([f'{element:{w}.{d}{pt}}' for element in v])
+
+
+if __name__ == '__main__':
+    main()