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MultipleInputPorts

vtk-examples/Cxx/Developers/MultipleInputPorts

Question

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Code

MultipleInputPorts.cxx

#include <vtkNew.h>
#include <vtkSphereSource.h>

#include "vtkTestMultipleInputPortsFilter.h"

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

  vtkNew<vtkSphereSource> sphereSource2;
  sphereSource2->SetThetaResolution(10);
  sphereSource2->Update();

  vtkNew<vtkTestMultipleInputPortsFilter> filter;
  filter->SetInputConnection(0, sphereSource1->GetOutputPort());
  filter->SetInputConnection(1, sphereSource2->GetOutputPort());
  filter->Update();

  return EXIT_SUCCESS;
}

vtkTestMultipleInputPortsFilter.cxx

#include "vtkTestMultipleInputPortsFilter.h"

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

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

CMakeLists.txt

cmake_minimum_required(VERSION 3.12 FATAL_ERROR)

project(MultipleInputPorts)

find_package(VTK COMPONENTS 
  CommonCore
  FiltersSources
)

if (NOT VTK_FOUND)
  message(FATAL_ERROR "MultipleInputPorts: 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(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}
)

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.