Examples/DataRepresentation/Mesh/RGBPointSet.cxx

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 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
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//  Software Guide : BeginLatex
//
//  The following example illustrates how a point set can be parameterized to
//  manage a particular pixel type. In this case, pixels of RGB type are used.
//  The first step is then to include the header files of the
//  \doxygen{RGBPixel} and \doxygen{PointSet} classes.
//
//  \index{itk::PointSet!RGBPixel}
//
//  Software Guide : EndLatex

// Software Guide : BeginCodeSnippet
#include "itkRGBPixel.h"
#include "itkPointSet.h"
// Software Guide : EndCodeSnippet


int main(int, char *[])
{
  //  Software Guide : BeginLatex
  //
  //  Then, the pixel type can be defined by selecting the type to be used to
  //  represent each one of the RGB components.
  //
  //  \index{itk::RGBPixel!Instantiation}
  //
  //  Software Guide : EndLatex

  // Software Guide : BeginCodeSnippet
  using PixelType = itk::RGBPixel< float >;
  // Software Guide : EndCodeSnippet


  //  Software Guide : BeginLatex
  //
  //  The newly defined pixel type is now used to instantiate the PointSet
  //  type and subsequently create a point set object.
  //
  //  Software Guide : EndLatex

  // Software Guide : BeginCodeSnippet
  using PointSetType = itk::PointSet< PixelType, 3 >;
  PointSetType::Pointer  pointSet = PointSetType::New();
  // Software Guide : EndCodeSnippet


  //  Software Guide : BeginLatex
  //
  //  The following code generates a circle and assigns RGB values to
  //  the points. The components of the RGB values in this example are
  //  computed to represent the position of the points.
  //
  //  \index{itk::PointSet!SetPoint()}
  //  \index{itk::PointSet!SetPointData()}
  //
  //  Software Guide : EndLatex

  // Software Guide : BeginCodeSnippet
  PointSetType::PixelType   pixel;
  PointSetType::PointType   point;
  unsigned int pointId =  0;
  constexpr double radius = 3.0;

  for(unsigned int i=0; i<360; i++)
    {
    const double angle = i * itk::Math::pi / 180.0;
    point[0] = radius * std::sin( angle );
    point[1] = radius * std::cos( angle );
    point[2] = 1.0;
    pixel.SetRed(    point[0] * 2.0 );
    pixel.SetGreen(  point[1] * 2.0 );
    pixel.SetBlue(   point[2] * 2.0 );
    pointSet->SetPoint( pointId, point );
    pointSet->SetPointData( pointId, pixel );
    pointId++;
    }
  // Software Guide : EndCodeSnippet


  //  Software Guide : BeginLatex
  //
  //  All the points on the PointSet are visited using the following code.
  //
  //  \index{itk::PointSet!GetPoints()}
  //  \index{itk::PointSet!points iterator}
  //  \index{itk::PointSet!iterating points}
  //
  //  Software Guide : EndLatex

  // Software Guide : BeginCodeSnippet
  using PointIterator = PointSetType::PointsContainer::ConstIterator;
  PointIterator pointIterator = pointSet->GetPoints()->Begin();
  PointIterator pointEnd      = pointSet->GetPoints()->End();
  while( pointIterator != pointEnd )
    {
    point = pointIterator.Value();
    std::cout << point << std::endl;
    ++pointIterator;
    }
  // Software Guide : EndCodeSnippet


  //  Software Guide : BeginLatex
  //
  //  Note that here the \code{ConstIterator} was used instead of the
  //  \code{Iterator} since the pixel values are not expected to be modified.
  //  ITK supports const-correctness at the API level.
  //
  //  Software Guide : EndLatex


  //  Software Guide : BeginLatex
  //
  //  All the pixel values on the PointSet are visited using the following code.
  //
  //  \index{itk::PointSet!GetPointData()}
  //  \index{itk::PointSet!data iterator}
  //  \index{itk::PointSet!iterating point data}
  //
  //  Software Guide : EndLatex


  // Software Guide : BeginCodeSnippet
  using PointDataIterator = PointSetType::PointDataContainer::ConstIterator;
  PointDataIterator pixelIterator = pointSet->GetPointData()->Begin();
  PointDataIterator pixelEnd      = pointSet->GetPointData()->End();
  while( pixelIterator != pixelEnd )
    {
    pixel = pixelIterator.Value();
    std::cout << pixel << std::endl;
    ++pixelIterator;
    }
  // Software Guide : EndCodeSnippet

  //  Software Guide : BeginLatex
  //
  //  Again, please note the use of the  \code{ConstIterator} instead of the
  //  \code{Iterator}.
  //
  //  \index{ConstIterator}
  //  \index{const-correctness}
  //
  //  Software Guide : EndLatex

  return EXIT_SUCCESS;

}