# ReadTextFile

VTKExamples/Cxx/IO/ReadTextFile

### Description

This example takes a plain text file of coordinates and reads them into a vtkPoints, which is then put into a vtkPolyData and displayed on the screen using a vtkVertexGlyphFilter.

An example file may look like: 1 2 3 4 5 6 7 8 9

Note

for a simpler way to read such a file, see SimplePointsReader.

### Code

ReadTextFile.cxx

    #include <vtkVersion.h>
    #include <vtkSmartPointer.h>
    #include <vtkPoints.h>
    #include <vtkVertexGlyphFilter.h>
    #include <vtkPolyDataMapper.h>
    #include <vtkActor.h>
    #include <vtkRenderer.h>
    #include <vtkRenderWindow.h>
    #include <vtkRenderWindowInteractor.h>

    #include <sstream>

    int main(int argc, char* argv[])
    {
      // Verify input arguments
      if ( argc != 2 )
      {
        std::cout << "Usage: " << argv[0]
                  << " Filename(.xyz)" << std::endl;
        return EXIT_FAILURE;
      }
      // Get all data from the file
      std::string filename = argv[1];
      std::ifstream filestream(filename.c_str());

      std::string line;
      vtkSmartPointer<vtkPoints> points =
        vtkSmartPointer<vtkPoints>::New();

      while(std::getline(filestream, line))
      {
        double x, y, z;
        std::stringstream linestream;
        linestream << line;
        linestream >> x >> y >> z;

        points->InsertNextPoint(x, y, z);
      }

      filestream.close();

      vtkSmartPointer<vtkPolyData> polyData =
        vtkSmartPointer<vtkPolyData>::New();

      polyData->SetPoints(points);

      vtkSmartPointer<vtkVertexGlyphFilter> glyphFilter =
        vtkSmartPointer<vtkVertexGlyphFilter>::New();
    #if VTK_MAJOR_VERSION <= 5
      glyphFilter->SetInputConnection(polyData->GetProducerPort());
    #else
      glyphFilter->SetInputData(polyData);
    #endif
      glyphFilter->Update();

      // Visualize

      vtkSmartPointer<vtkPolyDataMapper> mapper =
        vtkSmartPointer<vtkPolyDataMapper>::New();
      mapper->SetInputConnection(glyphFilter->GetOutputPort());

      vtkSmartPointer<vtkActor> actor =
        vtkSmartPointer<vtkActor>::New();
      actor->SetMapper(mapper);

      vtkSmartPointer<vtkRenderer> renderer =
        vtkSmartPointer<vtkRenderer>::New();
      renderer->AddActor(actor);
      renderer->SetBackground(.3, .6, .3); // Background color green

      vtkSmartPointer<vtkRenderWindow> renderWindow =
        vtkSmartPointer<vtkRenderWindow>::New();
      renderWindow->AddRenderer(renderer);

      vtkSmartPointer<vtkRenderWindowInteractor> renderWindowInteractor =
        vtkSmartPointer<vtkRenderWindowInteractor>::New();
      renderWindowInteractor->SetRenderWindow(renderWindow);

      renderWindowInteractor->Start();

      return EXIT_SUCCESS;
    }

### CMakeLists.txt

    cmake_minimum_required(VERSION 2.8)

    PROJECT(ReadTextFile)

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

    add_executable(ReadTextFile MACOSX_BUNDLE ReadTextFile.cxx )

    target_link_libraries(ReadTextFile ${VTK_LIBRARIES})

### Download and Build ReadTextFile

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

    cd ReadTextFile/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:

    ./ReadTextFile

WINDOWS USERS

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