Method colorize

3rdparty/qcustomplot/qcustomplot.cpp:16709–16755

! \overload This method is used to quickly convert a \a data array to colors. The colors will be output in the array \a scanLine. Both \a data and \a scanLine must have the length \a n when passed to this function. The data range that shall be used for mapping the data value to the gradient is passed in \a range. \a logarithmic indicates whether the data values shall be mapped to colors

  with alpha (see QImage::Format_ARGB32_Premultiplied).
*/
void QCPColorGradient::colorize(const double *data, const QCPRange &range, QRgb *scanLine, int n, int dataIndexFactor, bool logarithmic)
{
  // If you change something here, make sure to also adapt color() and the other colorize() overload
  if (!data)
  {
    qDebug() << Q_FUNC_INFO << "null pointer given as data";
    return;
  }
  if (!scanLine)
  {
    qDebug() << Q_FUNC_INFO << "null pointer given as scanLine";
    return;
  }
  if (mColorBufferInvalidated)
    updateColorBuffer();
  
  const bool skipNanCheck = mNanHandling == nhNone;
  const double posToIndexFactor = !logarithmic ? (mLevelCount-1)/range.size() : (mLevelCount-1)/qLn(range.upper/range.lower);
  for (int i=0; i<n; ++i)
  {
    const double value = data[dataIndexFactor*i];
    if (skipNanCheck || !std::isnan(value))
    {
      qint64 index = qint64((!logarithmic ? value-range.lower : qLn(value/range.lower)) * posToIndexFactor);
      if (!mPeriodic)
      {
        index = qBound(qint64(0), index, qint64(mLevelCount-1));
      } else
      {
        index %= mLevelCount;
        if (index < 0)
          index += mLevelCount;
      }
      scanLine[i] = mColorBuffer.at(index);
    } else
    {
      switch(mNanHandling)
      {
      case nhLowestColor: scanLine[i] = mColorBuffer.first(); break;
      case nhHighestColor: scanLine[i] = mColorBuffer.last(); break;
      case nhTransparent: scanLine[i] = qRgba(0, 0, 0, 0); break;
      case nhNanColor: scanLine[i] = mNanColor.rgba(); break;
      case nhNone: break; // shouldn't happen
      }
    }
  }
}

/*! \overload