[frequencies] seperate compute_frequencies betwin analyzer and display

Amuencha/AmuenchaModel.cpp

@@ -4,7 +4,17 @@ namespace Amuencha
 {
 void Model::prepare(setup info)
 {
-  sampling_rate = info.rate;
+  if (analyzer.isRunning()) return;
+
+  analyzer.setup(info.rate,
+                 [&] (const std::vector<float>& r_f,
+                     const std::vector<float>& p_s)
+  {
+    this->send_message({.reassigned_frequencies = r_f,
+                        .power_spectrum = p_s});
+  });
+
+  analyzer.start(QThread::NormalPriority);
 }
 
 void Model::operator()(tick t)

Amuencha/AmuenchaModel.hpp

@@ -35,22 +35,6 @@ public:
     halp::spinbox_i32<"Periods", halp::range{.min = 0, .max = 99, .init = 30}> periods;
   } inputs;
 
-  void process_message(const std::vector<float>& frequencies)
-  {
-    analyzer.setup(sampling_rate,
-                   frequencies,
-                   [&] (const std::vector<float>& r_f,
-                       const std::vector<float>& p_s)
-    {
-      this->send_message({.reassigned_frequencies = r_f,
-                          .power_spectrum = p_s});
-    },
-                   inputs.periods);
-
-    if (!analyzer.isRunning())
-      analyzer.start(QThread::NormalPriority);
-  }
-
   struct outs
   {
     halp::midi_bus<"Output"> midi;
@@ -68,7 +52,6 @@ public:
   struct ui;
 
 private:
-  float sampling_rate;
   FrequencyAnalyzer analyzer;
 };
 

Amuencha/AmuenchaUi.hpp

@@ -30,34 +30,22 @@ struct Model::ui
   // Define the communication between UI and processor.
   struct bus
   {
-    std::function<void(std::vector<float>&&)> send_message;
-
     // Set up connections
     void init(ui& self)
     {
-      self.spiral.set_frequencies_callback(
-          [&] { this->send_message(self.spiral.get_frequencies()); }
-          );
-
       self.controls.min.on_changed = [&] (int min)
       {
-        // self.spiral.set_min_max_notes(min, self.controls.max.value);
+        self.spiral.set_min_max_notes(min, self.controls.max.value);
       };
       self.controls.max.on_changed = [&] (int max)
       {
-        // self.spiral.set_min_max_notes(self.controls.min.value, max);
+        self.spiral.set_min_max_notes(self.controls.min.value, max);
       };
     }
 
     // Receive a message on the UI thread from the processing thread
     static void process_message(ui& self, const processor_to_ui& msg)
     {
-      if (!first_msg)
-      {
-        self.spiral.compute_frequencies();
-        first_msg = true;
-      }
-
       if (msg.power_spectrum.empty() ||
          msg.reassigned_frequencies.empty())
         return;
@@ -65,10 +53,6 @@ struct Model::ui
       self.spiral.power_handler(msg.reassigned_frequencies,
                                 msg.power_spectrum);
     }
-
-    static bool first_msg;
   };
 };
 }
-
-inline bool Amuencha::Model::ui::bus::first_msg = false;

Amuencha/FrequencyAnalyzer.cpp

@@ -174,13 +174,32 @@ void Amuencha::FrequencyAnalyzer::run()
     mutex.unlock();
 }
 
-void Amuencha::FrequencyAnalyzer::setup(float sampling_rate, const std::vector<float>& frequencies, PowerHandler&& handler, float periods, float max_buffer_duration)
+void Amuencha::FrequencyAnalyzer::setup(float sampling_rate,
+                                        PowerHandler&& handler,
+                                        int min_midi_note,
+                                        int max_midi_note,
+                                        float periods,
+                                        float max_buffer_duration)
 {
     // Block data processing while changing the data structures
     data_mutex.lock();
     
     this->samplerate_div_2pi = sampling_rate/two_pi;
-    this->frequencies = frequencies;
+
+    // Start with A440, but this could be parametrizable as well
+    const float fref = 440;
+    const float log2_fref = log2(fref);
+    const int aref = 69; // use the midi numbering scheme, because why not
+    float log2_fmin = (min_midi_note - aref) / 12. + log2_fref;
+    float log2_fmax = (max_midi_note - aref) / 12. + log2_fref;
+    int num_bins = max_midi_note - min_midi_note;
+
+    frequencies.resize(num_bins);
+    for (int b{0}; b < num_bins; ++b)
+    {
+      float bratio = (float)b / (num_bins - 1.);
+      frequencies[b] = exp2(log2_fmin + (log2_fmax - log2_fmin) * bratio);
+    }
     
     this->reassigned_frequencies = frequencies;
     this->power_spectrum.resize(frequencies.size());

Amuencha/FrequencyAnalyzer.hpp

@@ -56,7 +56,12 @@ public:
     //             At lower frequencies, long buffers are needed for accurate frequency separation.
     //             When that max buffer duration is reached, then it is capped and the frequency resolution decreases
     //             Too low buffers also limit the min_freq, duration must be >= period
-    void setup(float sampling_rate, const std::vector<float>& frequencies, PowerHandler&& handler, float periods = 20, float max_buffer_duration = 500);
+    void setup(float sampling_rate,
+               PowerHandler&& handler,
+               int min_midi_note = 24,
+               int max_midi_note = 72,
+               float periods = 20,
+               float max_buffer_duration = 500);
     
     // call to remove all existing chunk references
     // this may cause signal loss, but this is usually called precisely when the signal is lost...

Amuencha/SpiralDisplay.cpp

@@ -5,7 +5,6 @@ Amuencha::SpiralDisplay::SpiralDisplay()
     , max_midi_note{72}
     , gain{1.f}
     , visual_fading{1}
-    , on_new_frequencies{[]{}}
 {
   for (int i{0}; i < 12; i++)
     note_positions[i] = std::polar(.9f, half_pi - i * two_pi / 12);
@@ -24,16 +23,6 @@ void Amuencha::SpiralDisplay::set_min_max_notes(int min_midi_note, int max_midi_
   // update();
 }
 
-std::vector<float> Amuencha::SpiralDisplay::get_frequencies() const noexcept
-{
-  return frequencies;
-}
-
-void Amuencha::SpiralDisplay::set_frequencies_callback(std::function<void ()> &&callback)
-{
-  on_new_frequencies = callback;
-}
-
 void Amuencha::SpiralDisplay::compute_frequencies()
 {
   // Now the spiral
@@ -43,16 +32,17 @@ void Amuencha::SpiralDisplay::compute_frequencies()
   const int aref = 69; // use the midi numbering scheme, because why not
   float log2_fmin = (min_midi_note - aref) / 12. + log2_fref;
   float log2_fmax = (max_midi_note - aref) / 12. + log2_fref;
-  int approx_pix_bin_width = 3;
+  // int approx_pix_bin_width = 3;
   // number of frequency bins is the number of pixels
   // along the spiral path / approx_pix_bin_width
   // According to mathworld, the correct formula for the path length
   // from the origin involves sqrt and log computations.
   // Here, we just want some approximate pixel count
   // => use all circles for the approx
-  int num_octaves = (max_midi_note - min_midi_note + 11) / 12;
-  float approx_num_pix = 0.5 * half * pi * num_octaves;
-  int num_bins = (int)(approx_num_pix / approx_pix_bin_width);
+  // int num_octaves = (max_midi_note - min_midi_note + 11) / 12;
+  // float approx_num_pix = 0.5 * half * pi * num_octaves;
+  // int num_bins = (int)(approx_num_pix / approx_pix_bin_width);
+  int num_bins = max_midi_note - min_midi_note;
   // one more bound than number of bins
   display_bins.resize(num_bins + 1);
   bin_sizes.resize(num_bins);
@@ -66,21 +56,18 @@ void Amuencha::SpiralDisplay::compute_frequencies()
   // used to it (e.g. wikipedia note circle)
   const float theta_min = half_pi - two_pi * (min_midi_note % 12) / 12;
   // wrap in anti-trigonometric direction
-  const float theta_max = theta_min - two_pi * (max_midi_note - min_midi_note) / 12;
+  const float theta_max = theta_min - two_pi * (max_midi_note - min_midi_note - 1) / 12;
 
-  frequencies.resize(num_bins);
   for (int b{0}; b < num_bins; ++b)
   {
-    float bratio = (float)b / (num_bins - 1.);
-    frequencies[b] = exp2(log2_fmin + (log2_fmax - log2_fmin) * bratio);
-    bratio = (float)(b - 0.5) / (float)(num_bins - 1.);
+    float bratio = (float)(b - 0.5) / (float)(num_bins - 1.);
     display_bins[b] = exp2(log2_fmin + (log2_fmax - log2_fmin) * bratio);
     spiral_r_a[b].r = rmin + (rmax - rmin) * bratio;
     spiral_r_a[b].a = theta_min + (theta_max - theta_min) * bratio;
     spiral_positions[b] = std::polar(spiral_r_a[b].r, spiral_r_a[b].a);
   }
 
-  // repeat one more time to avoid a second for loops
+  // repeat one more time to avoid a second for loop
   float bratio = (float)(num_bins - 0.5) / (float)(num_bins - 1.);
   display_bins[num_bins] = exp2(log2_fmin + (log2_fmax - log2_fmin) * bratio);
   spiral_r_a[num_bins].r = rmin + (rmax - rmin) * bratio;
@@ -92,8 +79,6 @@ void Amuencha::SpiralDisplay::compute_frequencies()
 
   display_spectrum.resize(num_bins);
   fill(display_spectrum.begin(), display_spectrum.end(), 0.);
-
-  on_new_frequencies();
 }
 
 void Amuencha::SpiralDisplay::power_handler(const std::vector<float>& reassigned_frequencies,

Amuencha/SpiralDisplay.hpp

@@ -78,10 +78,6 @@ struct SpiralDisplay
     ctx.update();
   }
 
-  [[nodiscard]] std::vector<float> get_frequencies() const noexcept;
-
-  void set_frequencies_callback(std::function<void()>&& callback);
-
   // // Callback when the power spectrum is available at the prescribed frequencies
   // // The ID is that of the caller, setting the color of the display
   void power_handler(const std::vector<float>& reassigned_frequencies,
@@ -107,9 +103,6 @@ private:
 
   int min_midi_note, max_midi_note, visual_fading;
 
-  // central frequencies (log space)
-  std::vector<float> frequencies;
-
   // local copy for maintaining the display, adapted to the drawing bins
   std::vector<float> display_spectrum;
 
@@ -136,8 +129,6 @@ private:
   {
     return half - y * half;
   }
-
-  std::function<void()> on_new_frequencies;
 };
 
 }