topographicseries.cpp Example File

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  #include "topographicseries.h"

  using namespace QtDataVisualization;

  // Value used to encode height data as RGB value on PNG file
  const float packingFactor = 11983.0f;

  TopographicSeries::TopographicSeries()
  {
      setDrawMode(QSurface3DSeries::DrawSurface);
      setFlatShadingEnabled(true);
      setBaseColor(Qt::white);
  }

  TopographicSeries::~TopographicSeries()
  {
  }

  void TopographicSeries::setTopographyFile(const QString file, float width, float height)
  {
      QImage heightMapImage(file);
      uchar *bits = heightMapImage.bits();
      int imageHeight = heightMapImage.height();
      int imageWidth = heightMapImage.width();
      int widthBits = imageWidth * 4;
      float stepX = width / float(imageWidth);
      float stepZ = height / float(imageHeight);

      QSurfaceDataArray *dataArray = new QSurfaceDataArray;
      dataArray->reserve(imageHeight);
      for (int i = 0; i < imageHeight; i++) {
          int p = i * widthBits;
          float z = height - float(i) * stepZ;
          QSurfaceDataRow *newRow = new QSurfaceDataRow(imageWidth);
          for (int j = 0; j < imageWidth; j++) {
              uchar aa = bits[p + 0];
              uchar rr = bits[p + 1];
              uchar gg = bits[p + 2];
              uint color = uint((gg << 16) + (rr << 8) + aa);
              float y = float(color) / packingFactor;
              (*newRow)[j].setPosition(QVector3D(float(j) * stepX, y, z));
              p = p + 4;
          }
          *dataArray << newRow;
      }

      dataProxy()->resetArray(dataArray);

      m_sampleCountX = float(imageWidth);
      m_sampleCountZ = float(imageHeight);
  }