# DistanceBetweenPoints

VTKExamples/Cxx/SimpleOperations/DistanceBetweenPoints

### Description

This example finds the squared distance and the Euclidean distance between two 3D points.

Other Languages

See (Python), (Java), (CSharp)

### Code

DistanceBetweenPoints.cxx

    #include <vtkMath.h>

    int main(int, char *[])
    {
      // Create two points.
      double p0[3] = {0.0, 0.0, 0.0};
      double p1[3] = {1.0, 1.0, 1.0};

      // Find the squared distance between the points.
      double squaredDistance = vtkMath::Distance2BetweenPoints(p0, p1);

      // Take the square root to get the Euclidean distance between the points.
      double distance = sqrt(squaredDistance);

      // Output the results.
      std::cout << "SquaredDistance = " << squaredDistance << std::endl;
      std::cout << "Distance = " << distance << std::endl;

      return EXIT_SUCCESS;
    }

### CMakeLists.txt

    cmake_minimum_required(VERSION 3.3 FATAL_ERROR)

    project(DistanceBetweenPoints)

    find_package(VTK COMPONENTS
      vtkCommonCore QUIET)
    if (NOT VTK_FOUND)
      message("Skipping DistanceBetweenPoints: ${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(DistanceBetweenPoints MACOSX_BUNDLE DistanceBetweenPoints.cxx )
      target_link_libraries(DistanceBetweenPoints PRIVATE ${VTK_LIBRARIES})
    else ()
      # include all components
      add_executable(DistanceBetweenPoints MACOSX_BUNDLE DistanceBetweenPoints.cxx )
      target_link_libraries(DistanceBetweenPoints PRIVATE ${VTK_LIBRARIES})
      # vtk_module_autoinit is needed
      vtk_module_autoinit(
        TARGETS DistanceBetweenPoints
        MODULES ${VTK_LIBRARIES}
        )
    endif ()

### Download and Build DistanceBetweenPoints

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

    cd DistanceBetweenPoints/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:

    ./DistanceBetweenPoints

WINDOWS USERS

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