UnknownLengthArray

Description¶

The only difference between this example and the KnownLengthArray example is that SetNumberOfValues() is not called, and SetValue() is replaced by InsertNextValue().

Other languages

See (Java)

Question

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

Code¶

UnknownLengthArray.cxx

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

int main(int, char*[])
{
  vtkNew<vtkFloatArray> distances;
  distances->SetName("Distances");
  distances->SetNumberOfComponents(1);

  // set values
  for (vtkIdType i = 0; i < 5; i++)
  {
    float f = (float)i + 0.1;
    // this will allocate memory as necessary
    distances->InsertNextValue(f);
  }

  // get values
  for (vtkIdType i = 0; i < distances->GetNumberOfTuples(); i++)
  {
    float f = distances->GetValue(i);
    std::cout << f << std::endl;
  }

  return EXIT_SUCCESS;
}

CMakeLists.txt¶

cmake_minimum_required(VERSION 3.12 FATAL_ERROR)

project(UnknownLengthArray)

find_package(VTK COMPONENTS 
  CommonCore
)

if (NOT VTK_FOUND)
  message(FATAL_ERROR "UnknownLengthArray: Unable to find the VTK build folder.")
endif()

# 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(UnknownLengthArray MACOSX_BUNDLE UnknownLengthArray.cxx )
  target_link_libraries(UnknownLengthArray PRIVATE ${VTK_LIBRARIES}
)
# vtk_module_autoinit is needed
vtk_module_autoinit(
  TARGETS UnknownLengthArray
  MODULES ${VTK_LIBRARIES}
)

Download and Build UnknownLengthArray¶

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

cd UnknownLengthArray/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:

./UnknownLengthArray

WINDOWS USERS

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