Method updateDataExtremes

app/src/UI/Widgets/Plot.cpp:740–770

* @brief Refreshes the finite Y extremes that drive the area fill's bipolarity from * real data. A sign-clamped configured range short-circuits the per-frame scan; * otherwise the current samples are swept. Returns true when the bipolar or * all-negative verdict flips, so the caller refreshes the baseline binding. */

 *        all-negative verdict flips, so the caller refreshes the baseline binding.
 */
bool Widgets::Plot::updateDataExtremes(const DataModel::Dataset& dataset)
{
  const bool wasBipolar     = dataBipolar();
  const bool wasAllNegative = m_dataMaxY <= 0.0;

  if (signClampedRange(dataset)) {
    m_dataMinY = qMin(dataset.pltMin, dataset.pltMax);
    m_dataMaxY = qMax(dataset.pltMin, dataset.pltMax);
    return wasBipolar != dataBipolar() || wasAllNegative != (m_dataMaxY <= 0.0);
  }

  double dataMin = std::numeric_limits<double>::max();
  double dataMax = std::numeric_limits<double>::lowest();
  for (auto i = 0; i < m_data.size(); ++i) {
    const double value = m_data[i].y();
    if (std::isfinite(value)) {
      dataMin = qMin(dataMin, value);
      dataMax = qMax(dataMax, value);
    }
  }

  if (dataMin > dataMax) {
    m_dataMinY = 0.0;
    m_dataMaxY = 0.0;
  } else {
    m_dataMinY = dataMin;
    m_dataMaxY = dataMax;
  }

  return wasBipolar != dataBipolar() || wasAllNegative != (m_dataMaxY <= 0.0);
}

/**
 * @brief Computes the minimum and maximum values for a given axis of the plot.