Skip to content

SelectedVerticesAndEdges

vtk-examples/Cxx/Graphs/SelectedVerticesAndEdges


Description

  • Thanks to Eric Monson

Other languages

See (Python)

Question

If you have a question about this example, please use the VTK Discourse Forum

Code

SelectedVerticesAndEdges.cxx

#include <vtkAnnotationLink.h>
#include <vtkDoubleArray.h>
#include <vtkGraphLayoutStrategy.h>
#include <vtkGraphLayoutView.h>
#include <vtkGraphWriter.h>
#include <vtkHardwareSelector.h>
#include <vtkIdTypeArray.h>
#include <vtkInteractorStyleRubberBand2D.h>
#include <vtkMutableUndirectedGraph.h>
#include <vtkNamedColors.h>
#include <vtkNew.h>
#include <vtkObjectFactory.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkRenderedGraphRepresentation.h>
#include <vtkRenderer.h>
#include <vtkSelection.h>
#include <vtkSelectionNode.h>
#include <vtkSimple2DLayoutStrategy.h>
#include <vtkUnsignedCharArray.h>

namespace {
class RubberBandStyle : public vtkInteractorStyleRubberBand2D
{
public:
  static RubberBandStyle* New();
  vtkTypeMacro(RubberBandStyle, vtkInteractorStyleRubberBand2D);

  virtual void OnLeftButtonUp()
  {
    // Forward events
    vtkInteractorStyleRubberBand2D::OnLeftButtonUp();

    vtkSelection* selection = this->View->GetRepresentation()
                                  ->GetAnnotationLink()
                                  ->GetCurrentSelection();
    vtkSelectionNode* vertices;
    vtkSelectionNode* edges;
    if (selection->GetNode(0)->GetFieldType() == vtkSelectionNode::VERTEX)
    {
      vertices = selection->GetNode(0);
    }
    else if (selection->GetNode(0)->GetFieldType() == vtkSelectionNode::EDGE)
    {
      edges = selection->GetNode(0);
    }

    if (selection->GetNode(1)->GetFieldType() == vtkSelectionNode::VERTEX)
    {
      vertices = selection->GetNode(1);
    }
    else if (selection->GetNode(1)->GetFieldType() == vtkSelectionNode::EDGE)
    {
      edges = selection->GetNode(1);
    }

    vtkIdTypeArray* vertexList =
        dynamic_cast<vtkIdTypeArray*>(vertices->GetSelectionList());
    std::cout << "There are " << vertexList->GetNumberOfTuples()
              << " vertices selected." << std::endl;

    if (vertexList->GetNumberOfTuples() > 0)
    {
      std::cout << "Vertex Ids: ";
    }
    for (vtkIdType i = 0; i < vertexList->GetNumberOfTuples(); i++)
    {
      std::cout << vertexList->GetValue(i) << " ";
    }

    std::cout << std::endl;
    vtkIdTypeArray* edgeList =
        dynamic_cast<vtkIdTypeArray*>(edges->GetSelectionList());
    std::cout << "There are " << edgeList->GetNumberOfTuples()
              << " edges selected." << std::endl;
    if (edgeList->GetNumberOfTuples() > 0)
    {
      std::cout << "Edge Ids: ";
    }

    for (vtkIdType i = 0; i < edgeList->GetNumberOfTuples(); i++)
    {
      std::cout << edgeList->GetValue(i) << " ";
    }
    std::cout << std::endl;
  }

  vtkGraphLayoutView* View;
};
vtkStandardNewMacro(RubberBandStyle);
} // namespace

int main(int, char*[])
{
  vtkNew<vtkNamedColors> colors;

  vtkNew<vtkMutableUndirectedGraph> g;

  vtkIdType v1 = g->AddVertex();
  vtkIdType v2 = g->AddVertex();

  g->AddEdge(v1, v2);
  g->AddEdge(v1, v2);

  vtkNew<vtkGraphLayoutView> view;
  view->AddRepresentationFromInput(g);
  view->SetLayoutStrategy("Simple 2D");

  vtkNew<RubberBandStyle> style;
  style->View = view;
  view->SetInteractorStyle(style);

  view->GetRenderer()->SetBackground(colors->GetColor3d("Navy").GetData());
  view->GetRenderer()->SetBackground2(
      colors->GetColor3d("MidnightBlue").GetData());
  view->GetRenderWindow()->SetWindowName("SelectedVerticesAndEdges");
  view->ResetCamera();
  view->Render();

  view->GetInteractor()->Start();

  return EXIT_SUCCESS;
}

CMakeLists.txt

cmake_minimum_required(VERSION 3.3 FATAL_ERROR)

project(SelectedVerticesAndEdges)

find_package(VTK COMPONENTS 
  vtkCommonColor
  vtkCommonCore
  vtkCommonDataModel
  vtkFiltersGeneral
  vtkIOLegacy
  vtkInfovisLayout
  vtkInteractionStyle
  vtkRenderingContextOpenGL2
  vtkRenderingCore
  vtkRenderingFreeType
  vtkRenderingGL2PSOpenGL2
  vtkRenderingOpenGL2
  vtkViewsInfovis
  QUIET
)

if (NOT VTK_FOUND)
  message("Skipping SelectedVerticesAndEdges: ${VTK_NOT_FOUND_MESSAGE}")
  return ()
endif()
message (STATUS "VTK_VERSION: ${VTK_VERSION}")
if (VTK_VERSION VERSION_LESS "8.90.0")
  # old system
  include(${VTK_USE_FILE})
  add_executable(SelectedVerticesAndEdges MACOSX_BUNDLE SelectedVerticesAndEdges.cxx )
  target_link_libraries(SelectedVerticesAndEdges PRIVATE ${VTK_LIBRARIES})
else ()
  # include all components
  add_executable(SelectedVerticesAndEdges MACOSX_BUNDLE SelectedVerticesAndEdges.cxx )
  target_link_libraries(SelectedVerticesAndEdges PRIVATE ${VTK_LIBRARIES})
  # vtk_module_autoinit is needed
  vtk_module_autoinit(
    TARGETS SelectedVerticesAndEdges
    MODULES ${VTK_LIBRARIES}
    )
endif ()

Download and Build SelectedVerticesAndEdges

Click here to download SelectedVerticesAndEdges and its CMakeLists.txt file. Once the tarball SelectedVerticesAndEdges.tar has been downloaded and extracted,

cd SelectedVerticesAndEdges/build

If VTK is installed:

cmake ..

If VTK is not installed but compiled on your system, you will need to specify the path to your VTK build:

cmake -DVTK_DIR:PATH=/home/me/vtk_build ..

Build the project:

make

and run it:

./SelectedVerticesAndEdges

WINDOWS USERS

Be sure to add the VTK bin directory to your path. This will resolve the VTK dll's at run time.