VTK/Examples/Cxx/Visualization/Legend

Legend.cxx

#include <vtkVersion.h>
#include <vtkPolyDataMapper.h>
#include <vtkActor.h>
#include <vtkRenderWindow.h>
#include <vtkRenderer.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkPolyData.h>
#include <vtkCubeSource.h>
#include <vtkSphereSource.h>
#include <vtkLegendBoxActor.h>
#include <vtkNamedColors.h>

#include <vtkSmartPointer.h>
 
int main (int, char *[])
{
  vtkSmartPointer<vtkSphereSource> sphereSource = 
    vtkSmartPointer<vtkSphereSource>::New();
  sphereSource->SetCenter(0.0, 0.0, 0.0);
  sphereSource->SetRadius(5000.0);
  sphereSource->Update();

  vtkPolyData* polydata = sphereSource->GetOutput();
 
  // Create a mapper
  vtkSmartPointer<vtkPolyDataMapper> mapper = 
    vtkSmartPointer<vtkPolyDataMapper>::New();
#if VTK_MAJOR_VERSION <= 5
  mapper->SetInput(polydata);
#else
  mapper->SetInputData(polydata);
#endif
 
  // Create an actor
  vtkSmartPointer<vtkActor> actor = 
    vtkSmartPointer<vtkActor>::New();
  actor->SetMapper(mapper);
 
  // A renderer and render window
  vtkSmartPointer<vtkRenderer> renderer = 
    vtkSmartPointer<vtkRenderer>::New();
  vtkSmartPointer<vtkRenderWindow> renderWindow = 
    vtkSmartPointer<vtkRenderWindow>::New();
  renderWindow->AddRenderer(renderer);
 
  // An interactor
  vtkSmartPointer<vtkRenderWindowInteractor> renderWindowInteractor = 
    vtkSmartPointer<vtkRenderWindowInteractor>::New();
  renderWindowInteractor->SetRenderWindow(renderWindow);
 
  vtkSmartPointer<vtkLegendBoxActor> legend = 
    vtkSmartPointer<vtkLegendBoxActor>::New();
  legend->SetNumberOfEntries(2);

  vtkSmartPointer<vtkNamedColors> colors =
    vtkSmartPointer<vtkNamedColors>::New();

  double color[4];

  vtkSmartPointer<vtkCubeSource> legendBox = 
    vtkSmartPointer<vtkCubeSource>::New();
  legendBox->Update();
  colors->GetColor("tomato", color);
  legend->SetEntry(0, legendBox->GetOutput(), "Box", color);

  colors->GetColor("banana", color);
  legend->SetEntry(1, sphereSource->GetOutput(), "Ball", color);
  
  // place legend in lower right
  legend->GetPositionCoordinate()->SetCoordinateSystemToView();
  legend->GetPositionCoordinate()->SetValue(.5, -1.0);

  legend->GetPosition2Coordinate()->SetCoordinateSystemToView();
  legend->GetPosition2Coordinate()->SetValue(1.0, -0.5);

  legend->UseBackgroundOn();
  double background[4];
  colors->GetColor("warm_grey", background);
  legend->SetBackgroundColor(background);

  // Add the actors to the scene
  renderer->AddActor(actor);
  renderer->AddActor(legend);
  renderer->SetBackground(0,1,1); // Background color cyan
 
  // Render an image (lights and cameras are created automatically)
  renderWindow->Render();
 
  // Begin mouse interaction
  renderWindowInteractor->Start();
 
  return EXIT_SUCCESS;
}

Please try the new VTKExamples website.

CMakeLists.txt

cmake_minimum_required(VERSION 2.8)

PROJECT(Legend)

find_package(VTK REQUIRED)
include(${VTK_USE_FILE})

add_executable(Legend MACOSX_BUNDLE Legend.cxx)

if(VTK_LIBRARIES)
  target_link_libraries(Legend ${VTK_LIBRARIES})
else()
  target_link_libraries(Legend vtkHybrid vtkWidgets)
endif()

Download and Build Legend

Click here to download Legend. and its CMakeLists.txt file.

Once the tarball Legend.tar has been downloaded and extracted,

cd Legend/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:

./Legend

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

One of the items in the legend does not have an icon.