Method paintMaximumIntensities_

src/openms_gui/source/VISUAL/Painter2DBase.cpp:330–435

  void Painter2DPeak::paintMaximumIntensities_(QPainter& painter, Plot2DCanvas* canvas, Size layer_index, Size rt_pixel_count, Size mz_pixel_count)
  {
    // set painter to black (we operate directly on the pixels for all colored data)
    painter.setPen(Qt::black);
    const double snap_factor = canvas->snap_factors_[layer_index];
    const auto& map = *layer_->getPeakData();
    const auto& area = canvas->visible_area_.getAreaUnit();

    auto RT_or_IM_paint = [&](const DimInfo& mapper) {
      // note: the variables are named, assuming we have an RT+mz canvas.
      //       However, by using 'DimInfo' this could well be an IM+mz canvas (i.e. an IM Frame)
      
      const double rt_min = mapper.dim_.getMin();
      const double rt_max = mapper.dim_.getMax();
      const double mz_min = area.getMinMZ();
      const double mz_max = area.getMaxMZ();

      // calculate pixel size in data coordinates
      double rt_step_size = (rt_max - rt_min) / rt_pixel_count;
      double mz_step_size = (mz_max - mz_min) / mz_pixel_count;

      // start at first visible RT scan
      Size scan_index = std::distance(map.begin(), mapper.getFirstScan(rt_min));
      vector<Size> scan_indices, peak_indices;
      // iterate over all pixels (RT dimension)
      for (Size rt = 0; rt < rt_pixel_count; ++rt)
      {
        // interval in data coordinates for the current pixel
        double rt_start = rt_min + rt_step_size * rt;
        double rt_end = rt_start + rt_step_size;
        // cout << "rt: " << rt << " (" << rt_start << " - " << rt_end << ")" << endl;

        // reached the end of data
        if (rt_end >= mapper.getMaximum())
        {
          break;
        }
        // determine the relevant spectra and reserve an array for the peak indices
        scan_indices.clear();
        peak_indices.clear();
        for (Size i = scan_index; i < map.size(); ++i)
        {
          const auto& spec = map[i];
          if (mapper.getValue(spec) >= rt_end)
          {
            scan_index = i; // store last scan index for next RT pixel
            break;
          }
          if (spec.getMSLevel() == 1 && !spec.empty())
          {
            scan_indices.push_back(i);
            peak_indices.push_back(spec.MZBegin(mz_min) - spec.begin());
          }
        }

        if (scan_indices.empty())
        {
          continue;