Method _addPitchBends

Lib/Model/Notes.cpp:245–283

}

void Notes::_addPitchBends(std::vector<Event>& inOutEvents,
                           const std::vector<std::vector<float>>& inContoursPG,
                           int inNumBinsTolerance)
{
    for (auto& event: inOutEvents) {
        // midi_pitch_to_contour_bin
        int note_idx =
            CONTOURS_BINS_PER_SEMITONE
            * (event.pitch - 69 + 12 * static_cast<int>(std::round(std::log2(440.0f / ANNOTATIONS_BASE_FREQUENCY))));

        static constexpr int N_FREQ_BINS_CONTOURS = NUM_FREQ_OUT * CONTOURS_BINS_PER_SEMITONE;
        int note_start_idx = std::max(note_idx - inNumBinsTolerance, 0);
        int note_end_idx = std::min(N_FREQ_BINS_CONTOURS, note_idx + inNumBinsTolerance + 1);

        const auto gauss_start = static_cast<float>(std::max(0, inNumBinsTolerance - note_idx));
        const auto pb_shift = inNumBinsTolerance - std::max(0, inNumBinsTolerance - note_idx);

        for (int i = event.startFrame; i < event.endFrame; i++) {
            int bend = 0;
            float max = 0;
            for (int j = note_start_idx; j < note_end_idx; j++) {
                int k = j - note_start_idx;
                float x = gauss_start + static_cast<float>(k);
                float n = x - static_cast<float>(inNumBinsTolerance);

                static constexpr float std = 5.0f;

                // Gaussian
                float w = std::exp(-(n * n) / (2.0f * std * std)) * inContoursPG[i][j];

                if (w > max) {
                    bend = k;
                    max = w;
                }
            }
            event.bends.emplace_back(bend - pb_shift);
        }
    }
}