PolyDataAlgorithmReader
vtk-examples/Cxx/Developers/PolyDataAlgorithmReader
Description¶
This example demonstrates a reader that takes nothing as input and produces a vtkPolyData as output.
Question
If you have a question about this example, please use the VTK Discourse Forum
Code¶
PolyDataAlgorithmReader.cxx
#include <vtkSmartPointer.h>
#include <vtkPolyData.h>
#include <vtkTestReader.h>
int main (int, char *[])
{
vtkSmartPointer<vtkTestReader> reader =
vtkSmartPointer<vtkTestReader>::New();
reader->Update();
vtkPolyData* polydata = reader->GetOutput();
polydata->Print(std::cout);
return EXIT_SUCCESS;
}
vtkTestReader.h
#ifndef __vtkTestReader_h
#define __vtkTestReader_h
#include <vtkPolyDataAlgorithm.h>
class vtkTestReader : public vtkPolyDataAlgorithm
{
public:
vtkTypeMacro(vtkTestReader,vtkPolyDataAlgorithm);
void PrintSelf(ostream& os, vtkIndent indent);
static vtkTestReader *New();
protected:
vtkTestReader();
~vtkTestReader();
int FillOutputPortInformation( int port, vtkInformation* info );
int RequestData(vtkInformation *, vtkInformationVector **, vtkInformationVector *);
private:
vtkTestReader(const vtkTestReader&); // Not implemented.
void operator=(const vtkTestReader&); // Not implemented.
char* FileName;
};
#endif
vtkTestReader.cxx
#include <vtkTestReader.h>
#include <vtkObjectFactory.h>
#include <vtkStreamingDemandDrivenPipeline.h>
#include <vtkInformationVector.h>
#include <vtkInformation.h>
#include <vtkDataObject.h>
#include <vtkNew.h>
vtkStandardNewMacro(vtkTestReader);
vtkTestReader::vtkTestReader()
{
this->FileName = NULL;
this->SetNumberOfInputPorts(0);
this->SetNumberOfOutputPorts(1);
}
vtkTestReader::~vtkTestReader()
{
}
// This override is not needed as the FillOutputPortInformation on vtkPolyDataAlgorithm
// does this. Override this if you need something different from one output that
// is a vtkPolyData
int vtkTestReader::FillOutputPortInformation( int port, vtkInformation* info )
{
if ( port == 0 )
{
info->Set(vtkDataObject::DATA_TYPE_NAME(), "vtkPolyData" );
return 1;
}
return 0;
}
int vtkTestReader::RequestData(
vtkInformation *vtkNotUsed(request),
vtkInformationVector **vtkNotUsed(inputVector),
vtkInformationVector *outputVector)
{
// Get the output
vtkPolyData *output = vtkPolyData::GetData(outputVector,0)
vtkNew<vtkPolyData> polydata;
vtkNew<vtkPoints> points;
points->InsertNextPoint(0.0, 0.0, 0.0);
polydata->SetPoints(points.GetPointer());
//output = polydata.GetPointer(); //doesn't work
output->ShallowCopy(polydata.GetPointer());
return 1;
}
//----------------------------------------------------------------------------
void vtkTestReader::PrintSelf(ostream& os, vtkIndent indent)
{
this->Superclass::PrintSelf(os,indent);
os << indent << "File Name: "
<< (this->FileName ? this->FileName : "(none)") << "\n";
}
CMakeLists.txt¶
cmake_minimum_required(VERSION 3.12 FATAL_ERROR)
project(PolyDataAlgorithmReader)
find_package(VTK COMPONENTS
vtkCommonCore
vtkCommonDataModel
QUIET
)
if (NOT VTK_FOUND)
message("Skipping PolyDataAlgorithmReader: ${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(PolyDataAlgorithmReader MACOSX_BUNDLE PolyDataAlgorithmReader.cxx )
target_link_libraries(PolyDataAlgorithmReader 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(PolyDataAlgorithmReader MACOSX_BUNDLE PolyDataAlgorithmReader.cxx )
target_link_libraries(PolyDataAlgorithmReader PRIVATE ${VTK_LIBRARIES})
# vtk_module_autoinit is needed
vtk_module_autoinit(
TARGETS PolyDataAlgorithmReader
MODULES ${VTK_LIBRARIES}
)
endif()
Download and Build PolyDataAlgorithmReader¶
Click here to download PolyDataAlgorithmReader and its CMakeLists.txt file. Once the tarball PolyDataAlgorithmReader.tar has been downloaded and extracted,
cd PolyDataAlgorithmReader/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:
./PolyDataAlgorithmReader
WINDOWS USERS
Be sure to add the VTK bin directory to your path. This will resolve the VTK dll's at run time.