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VectorArrayUnknownLength

vtk-examples/Cxx/Utilities/VectorArrayUnknownLength

Description

This example creates a VTK style float array of vectors. This can be easily interchanged with vtkIntArray, vtkDoubleArray, etc.

The only difference between this example and the VectorArrayKnownLength example is that SetNumberOfValues() is not called, and SetTuple() is replaced by InsertNextTuple().

Question

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

Code

VectorArrayUnknownLength.cxx

#include <vtkFloatArray.h>
#include <vtkNew.h>

int main(int, char*[])
{
  vtkNew<vtkFloatArray> distances;
  distances->SetName("Distances");
  distances->SetNumberOfComponents(3);

  // set values
  for (vtkIdType i = 0; i < 5; i++)
  {
    float tuple[3];
    tuple[0] = (float)i + 0.1;
    tuple[1] = (float)i + 0.2;
    tuple[2] = (float)i + 0.3;
    // this will allocate memory as necessary
    distances->InsertNextTuple(tuple);
  }

  // get values
  for (vtkIdType i = 0; i < distances->GetNumberOfTuples(); i++)
  {
    double d[3];
    distances->GetTuple(i, d);
    std::cout << d[0] << " " << d[1] << " " << d[2] << std::endl;
  }

  return EXIT_SUCCESS;
}

CMakeLists.txt

cmake_minimum_required(VERSION 3.3 FATAL_ERROR)

project(VectorArrayUnknownLength)

find_package(VTK COMPONENTS 
  vtkCommonCore
  QUIET
)

if (NOT VTK_FOUND)
  message("Skipping VectorArrayUnknownLength: ${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(VectorArrayUnknownLength MACOSX_BUNDLE VectorArrayUnknownLength.cxx )
  target_link_libraries(VectorArrayUnknownLength PRIVATE ${VTK_LIBRARIES})
else()
  # Prevent a "command line is too long" failure in Windows.
  set(CMAKE_NINJA_FORCE_RESPONSE_FILE "ON" CACHE BOOL "Force Ninja to use response files.")
  add_executable(VectorArrayUnknownLength MACOSX_BUNDLE VectorArrayUnknownLength.cxx )
  target_link_libraries(VectorArrayUnknownLength PRIVATE ${VTK_LIBRARIES})
  # vtk_module_autoinit is needed
  vtk_module_autoinit(
    TARGETS VectorArrayUnknownLength
    MODULES ${VTK_LIBRARIES}
    )
endif()

Download and Build VectorArrayUnknownLength

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

cd VectorArrayUnknownLength/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:

./VectorArrayUnknownLength

WINDOWS USERS

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