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MultipleInputPorts

vtk-examples/Cxx/Developers/MultipleInputPorts

Question

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Code

MultipleInputPorts.cxx

#include <vtkSmartPointer.h>
#include <vtkSphereSource.h>

#include "vtkTestMultipleInputPortsFilter.h"

int main (int /* argc */, char * /* argv */ [])
{
  vtkSmartPointer<vtkSphereSource> sphereSource1 =
      vtkSmartPointer<vtkSphereSource>::New();
  sphereSource1->SetThetaResolution(5);
  sphereSource1->Update();

  vtkSmartPointer<vtkSphereSource> sphereSource2 =
      vtkSmartPointer<vtkSphereSource>::New();
  sphereSource2->SetThetaResolution(10);
  sphereSource2->Update();

  vtkSmartPointer<vtkTestMultipleInputPortsFilter> filter =
      vtkSmartPointer<vtkTestMultipleInputPortsFilter>::New();
  filter->SetInputConnection(0, sphereSource1->GetOutputPort());
  filter->SetInputConnection(1, sphereSource2->GetOutputPort());
  filter->Update();

  return EXIT_SUCCESS;
}

vtkTestMultipleInputPortsFilter.h

// .NAME vtkTestMultipleInputPortsFilter
// .SECTION Description
// vtkTestMultipleInputPortsFilter

#ifndef __vtkTestMultipleInputPortsFilter_h
#define __vtkTestMultipleInputPortsFilter_h

#include <vtkPolyDataAlgorithm.h>

class vtkTestMultipleInputPortsFilter : public vtkPolyDataAlgorithm
{
public:
  static vtkTestMultipleInputPortsFilter *New();
  vtkTypeMacro(vtkTestMultipleInputPortsFilter,vtkPolyDataAlgorithm);

protected:
  vtkTestMultipleInputPortsFilter();
  ~vtkTestMultipleInputPortsFilter() {}

  int FillInputPortInformation( int port, vtkInformation* info ) override;
  int RequestData(vtkInformation *, vtkInformationVector **, vtkInformationVector *) override;

private:
  vtkTestMultipleInputPortsFilter(const vtkTestMultipleInputPortsFilter&) = delete;
  void operator=(const vtkTestMultipleInputPortsFilter&) = delete;

};

#endif

vtkTestMultipleInputPortsFilter.cxx

#include "vtkTestMultipleInputPortsFilter.h"

#include <vtkObjectFactory.h>
#include <vtkStreamingDemandDrivenPipeline.h>
#include <vtkInformationVector.h>
#include <vtkInformation.h>
#include <vtkDataObject.h>
#include <vtkSmartPointer.h>

vtkStandardNewMacro(vtkTestMultipleInputPortsFilter);

vtkTestMultipleInputPortsFilter::vtkTestMultipleInputPortsFilter()
{
  this->SetNumberOfInputPorts(2);
}

int vtkTestMultipleInputPortsFilter::FillInputPortInformation( int port, vtkInformation* info )
{
  if ( port == 0 )
  {
    info->Set(vtkDataObject::DATA_TYPE_NAME(), "vtkPolyData" );
    return 1;
  }
  else if(port == 1)
  {
    info->Set(vtkDataObject::DATA_TYPE_NAME(), "vtkPolyData" );
    return 1;
  }

  return 0;
}

int vtkTestMultipleInputPortsFilter::RequestData(vtkInformation *vtkNotUsed(request),
                                             vtkInformationVector **inputVector,
                                             vtkInformationVector *outputVector)
{

  // get the info objects
  vtkInformation *inInfo0 = inputVector[0]->GetInformationObject(0);
  vtkInformation *inInfo1 = inputVector[1]->GetInformationObject(0);

  vtkInformation *outInfo = outputVector->GetInformationObject(0);


  // get the input and ouptut
  vtkPolyData *input0 = dynamic_cast<vtkPolyData*>(
      inInfo0->Get(vtkDataObject::DATA_OBJECT()));

  std::cout << "input0 has " << input0->GetNumberOfPoints() << " points." << std::endl;

  vtkPolyData *input1 = dynamic_cast<vtkPolyData*>(
      inInfo1->Get(vtkDataObject::DATA_OBJECT()));

  std::cout << "input1 has " << input1->GetNumberOfPoints() << " points." << std::endl;

  vtkPolyData *output = dynamic_cast<vtkPolyData*>(
      outInfo->Get(vtkDataObject::DATA_OBJECT()));

  output->ShallowCopy(input0);

  return 1;
}

CMakeLists.txt

cmake_minimum_required(VERSION 3.3 FATAL_ERROR)

project(MultipleInputPorts)

find_package(VTK COMPONENTS 
  vtkCommonCore
  vtkFiltersSources
  QUIET
)

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

Download and Build MultipleInputPorts

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

cd MultipleInputPorts/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:

./MultipleInputPorts

WINDOWS USERS

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