Line data    Source code

       1              : #pragma once
       2              : 
       3              : #include <array>
       4              : #include <complex>
       5              : 
       6              : #include "common.h"
       7              : 
       8              : namespace Amplitron {
       9              : 
      10              : /**
      11              :  * @brief Performs Fast Fourier Transform (FFT) and frequency magnitude calculations.
      12              :  * Completely decoupled from GUI rendering libraries (ImGui/SDL).
      13              :  */
      14              : class SpectrumAnalyzer {
      15              :    public:
      16              :     static constexpr int FFT_SIZE = 2048;
      17              :     static constexpr int FFT_BINS = FFT_SIZE / 2;
      18              :     static constexpr int DISPLAY_BARS = 96;
      19              : 
      20              :     SpectrumAnalyzer();
      21              : 
      22              :     /**
      23              :      * @brief Perform FFT analysis and update the smoothed frequency DB arrays.
      24              :      */
      25              :     void update(const float* input_samples, const float* output_samples, int sample_rate,
      26              :                 float dt_seconds);
      27              : 
      28              :     // Getters for display data (so the UI only reads raw arrays)
      29          966 :     const std::array<float, DISPLAY_BARS>& smoothed_input_db() const { return smoothed_input_db_; }
      30          388 :     const std::array<float, DISPLAY_BARS>& smoothed_output_db() const {
      31          388 :         return smoothed_output_db_;
      32              :     }
      33          196 :     const std::array<float, DISPLAY_BARS>& input_peak_db() const { return input_peak_db_; }
      34          196 :     const std::array<float, DISPLAY_BARS>& output_peak_db() const { return output_peak_db_; }
      35              : 
      36              :    private:
      37              :     void compute_spectrum_bars(const float* samples, int sample_rate,
      38              :                                std::array<float, DISPLAY_BARS>& bars_db);
      39              :     void run_fft(std::array<std::complex<float>, FFT_SIZE>& data) const;
      40              : 
      41              :     std::array<float, FFT_SIZE> window_{};
      42              :     std::array<std::complex<float>, FFT_SIZE> fft_work_{};
      43              : 
      44              :     std::array<float, DISPLAY_BARS> smoothed_input_db_{};
      45              :     std::array<float, DISPLAY_BARS> smoothed_output_db_{};
      46              :     std::array<float, DISPLAY_BARS> input_peak_db_{};
      47              :     std::array<float, DISPLAY_BARS> output_peak_db_{};
      48              : };
      49              : 
      50              : }  // namespace Amplitron