Examples/DataRepresentation/Mesh/RGBPointSet.cxx

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 *
 *  Copyright NumFOCUS
 *
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
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 *         https://www.apache.org/licenses/LICENSE-2.0.txt
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 *  distributed under the License is distributed on an "AS IS" BASIS,
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 *  See the License for the specific language governing permissions and
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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>;
  auto 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();
  const 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();
  const 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;
}