Finish BLLT loading from wav files

examples/Demo/Source/MainComponent.cpp

@@ -1657,7 +1657,7 @@ struct WavetableDemo : public juce::Component
         if (int size = gin::getWavetableSize (mb); size > 0)
         {
             auto is = new juce::MemoryInputStream (mb.getData(), mb.getSize(), false);
-            auto reader = juce::WavAudioFormat().createReaderFor (is, true);
+            auto reader = std::unique_ptr<juce::AudioFormatReader> (juce::WavAudioFormat().createReaderFor (is, true));
 
             if (reader)
             {
@@ -1716,9 +1716,91 @@ struct WavetableDemo : public juce::Component
     std::unique_ptr<gin::WTOscillator> osc;
 };
 
+//==============================================================================
+struct BLLTDemo : public juce::Component
+{
+    BLLTDemo()
+    {
+        setName ("BLLT");
+
+        juce::AudioSampleBuffer buf (1, 2048);
+
+        auto w = buf.getWritePointer (0);
+        for (auto i = 0; i < 2048; i++)
+            w[i] = tables.processSquare (0.0f, i / 2048.0f);
+
+        bllt.loadFromBuffer (buf, 44100, 12);
+    }
+
+    void paint (juce::Graphics& g) override
+    {
+
+        //
+        // From formula
+        //
+        {
+            auto area = getLocalBounds();
+            auto note = 0.5f;
+            for (int i = 0; i < bllt.tables.size(); i++)
+            {
+                auto rc = area.removeFromTop (getHeight() / bllt.tables.size()).reduced (3);
+
+                juce::Path p;
+
+                for (auto x = 0; x < 2048; x++)
+                {
+                    auto fx = x / 2048.0f * rc.getWidth() + rc.getX();
+                    auto fy = tables.processSquare (note, x / 2048.0f) * rc.getHeight() / 2.0f + rc.getCentreY();
+
+                    if (x == 0)
+                        p.startNewSubPath (fx, fy);
+                    else
+                        p.lineTo (fx, fy);
+                }
+
+                g.setColour (juce::Colours::green);
+                g.strokePath (p, juce::PathStrokeType (1.0f));
+
+                note += 12.0f;
+            }
+        }
+
+        //
+        // From wavefile
+        //
+        {
+            auto area = getLocalBounds();
+            for (int i = 0; i < bllt.tables.size(); i++)
+            {
+                auto& t = *bllt.tables[i];
+                auto rc = area.removeFromTop (getHeight() / bllt.tables.size()).reduced (3);
+
+                juce::Path p;
+
+                for (auto x = 0; x < 2048; x++)
+                {
+                    auto fx = x / 2048.0f * rc.getWidth() + rc.getX();
+                    auto fy = t.processSample (x / 2048.0f) * rc.getHeight() / 2.0f + rc.getCentreY();
+
+                    if (x == 0)
+                        p.startNewSubPath (fx, fy);
+                    else
+                        p.lineTo (fx, fy);
+                }
+                g.setColour (juce::Colours::yellow);
+                g.strokePath (p, juce::PathStrokeType (1.0f));
+            }
+        }
+    }
+
+    gin::BandLimitedLookupTables tables {44100, 12, 2048};
+    gin::BandLimitedLookupTable bllt;
+};
+
 //==============================================================================
 MainContentComponent::MainContentComponent()
 {
+    demoComponents.add (new BLLTDemo());
     demoComponents.add (new WavetableDemo());
 	demoComponents.add (new CatenaryDemo());
     demoComponents.add (new EllipseDemo());

modules/gin_dsp/dsp/gin_bandlimitedlookuptable.cpp

@@ -118,6 +118,9 @@ void BandLimitedLookupTable::loadFromBuffer (juce::AudioSampleBuffer& buffer, do
 
     notesPerTable = notesPerTable_;
 
+    juce::dsp::FFT fft (juce::roundToInt (std::log2 (sz)));
+    jassert (fft.getSize() == sz);
+
     for (double note = notesPerTable + 0.5; note < 127.0; note += notesPerTable)
     {
         auto noteFreq = getMidiNoteInHertz (note);
@@ -133,10 +136,34 @@ void BandLimitedLookupTable::loadFromBuffer (juce::AudioSampleBuffer& buffer, do
         }
         else
         {
+            auto index2Freq = [&] (int i)
+            {
+                return float (i * (sampleRate / sz));
+            };
+
+            auto d = buffer.getReadPointer (0);
+            auto ratio = noteFreq / baseFreq;
+
+            std::vector<juce::dsp::Complex<float>> time;
+            std::vector<juce::dsp::Complex<float>> freq;
+
+            time.resize (sz);
+            freq.resize (sz);
+
+            for (auto i = 0; i < sz; i++)
+                time[i] = { d[i], 0.0f };
+
+            fft.perform (time.data(), freq.data(), false);
+
+            for (auto i = 0; i < sz; i++)
+                if (index2Freq (i) * ratio > sampleRate / 2)
+                    freq[i] = {0.0f, 0.0f};
+
+            fft.perform (freq.data(), time.data(), true);
+
             auto func = [&] (float phase)
             {
-                auto data = buffer.getReadPointer (0);
-                return data[int (phase * float(sz)) % sz];
+                return time[int (phase * float(sz)) % sz].real();
             };
 
             tables.add (new juce::dsp::LookupTableTransform<float> (func, 0.0f, 1.0f, (size_t) sz + 1));

modules/gin_dsp/dsp/gin_wtoscillators.cpp

@@ -71,7 +71,7 @@ void WTOscillator::process (float noteL, float noteR, const Params& params, juce
 void WTOscillator::processAdding (float note, const Params& params, juce::AudioSampleBuffer& buffer)
 {
     if (bllt.size() == 0) return;
-    int ti = std::min (bllt.size() - 1, int (float ( bllt.size() ) * params.pw));
+    int ti = std::min (bllt.size() - 1, int (float (bllt.size()) * params.pw));
 
     float freq = float (std::min (sampleRate / 2.0, 440.0 * std::pow (2.0, (note - 69.0) / 12.0)));
     float delta = 1.0f / (float ((1.0f / freq) * sampleRate));
@@ -96,7 +96,7 @@ void WTOscillator::processAdding (float note, const Params& params, juce::AudioS
 void WTOscillator::processAdding (float noteL, float noteR, const Params& params, juce::AudioSampleBuffer& buffer)
 {
     if (bllt.size() == 0) return;
-    int ti = std::min (bllt.size() - 1, int (float ( bllt.size() ) * params.pw));
+    int ti = std::min (bllt.size() - 1, int (float (bllt.size()) * params.pw));
 
     float freqL = float (std::min (sampleRate / 2.0, 440.0 * std::pow (2.0, (noteL - 69.0) / 12.0)));
     float freqR = float (std::min (sampleRate / 2.0, 440.0 * std::pow (2.0, (noteR - 69.0) / 12.0)));