Allow FFT object to be constructed without inverse FFT. Added SpectralVisualizer component that does an extremely inefficient visualization of the spectral processing stages.

Source/PS_Source/Stretch.cpp

@@ -20,7 +20,7 @@
 #include <stdlib.h>
 #include <math.h>
 
-FFT::FFT(int nsamples_)
+FFT::FFT(int nsamples_, bool no_inverse)
 {
     nsamples=nsamples_;
 	if (nsamples%2!=0) {
@@ -43,13 +43,15 @@ FFT::FFT(int nsamples_)
     {
         //fftwf_plan_with_nthreads(2);
         planfftw=fftwf_plan_r2r_1d(nsamples,data.data(),data.data(),FFTW_R2HC,FFTW_MEASURE);
-        planifftw=fftwf_plan_r2r_1d(nsamples,data.data(),data.data(),FFTW_HC2R,FFTW_MEASURE);
+        if (no_inverse == false)
+			planifftw=fftwf_plan_r2r_1d(nsamples,data.data(),data.data(),FFTW_HC2R,FFTW_MEASURE);
     } else
     {
         //fftwf_plan_with_nthreads(2);
         planfftw=fftwf_plan_r2r_1d(nsamples,data.data(),data.data(),FFTW_R2HC,FFTW_ESTIMATE);
         //fftwf_plan_with_nthreads(2);
-        planifftw=fftwf_plan_r2r_1d(nsamples,data.data(),data.data(),FFTW_HC2R,FFTW_ESTIMATE);
+        if (no_inverse == false)
+			planifftw=fftwf_plan_r2r_1d(nsamples,data.data(),data.data(),FFTW_HC2R,FFTW_ESTIMATE);
     }
     //double t1 = Time::getMillisecondCounterHiRes();
     //Logger::writeToLog("Creating FFTW3 plans took "+String(t1-t0)+ "ms");
@@ -64,7 +66,8 @@ FFT::FFT(int nsamples_)
 FFT::~FFT()
 {
 	fftwf_destroy_plan(planfftw);
-	fftwf_destroy_plan(planifftw);
+	if (planifftw!=nullptr)
+		fftwf_destroy_plan(planifftw);
 };
 
 void FFT::smp2freq()

Source/PS_Source/Stretch.h

@@ -122,7 +122,7 @@ enum FFTWindow{W_RECTANGULAR,W_HAMMING,W_HANN,W_BLACKMAN,W_BLACKMAN_HARRIS};
 class FFT
 {//FFT class that considers phases as random
 	public:
-		FFT(int nsamples_);//samples must be even
+		FFT(int nsamples_, bool no_inverse=false);//samples must be even
 		~FFT();
 		void smp2freq();//input is smp, output is freq (phases are discarded)
 		void freq2smp();//input is freq,output is smp (phases are random)

Source/PluginEditor.cpp

@@ -42,7 +42,7 @@ PaulstretchpluginAudioProcessorEditor::PaulstretchpluginAudioProcessorEditor (Pa
 	addAndMakeVisible(&m_rec_enable);
 	m_rec_enable.setButtonText("Capture");
 	attachCallback(m_rec_enable, [this]() { processor.setRecordingEnabled(m_rec_enable.getToggleState()); });
-
+	addAndMakeVisible(&m_specvis);
 	setSize (700, 30+pars.size()*25+200);
 	m_wavecomponent.TimeSelectionChangedCallback = [this](Range<double> range, int which)
 	{
@@ -56,6 +56,7 @@ PaulstretchpluginAudioProcessorEditor::PaulstretchpluginAudioProcessorEditor (Pa
 	m_wavecomponent.ShowFileCacheRange = true;
 	startTimer(1, 100);
 	startTimer(2, 1000);
+	startTimer(3, 500);
 	m_wavecomponent.startTimer(100);
 	
 }
@@ -82,7 +83,8 @@ void PaulstretchpluginAudioProcessorEditor::resized()
 		m_parcomps[i]->setBounds(1, 30 + i * 25, getWidth()-2, 24);
 	}
 	int yoffs = m_parcomps.back()->getBottom() + 1;
-	m_wavecomponent.setBounds(1, yoffs, getWidth()-2, getHeight()-1-yoffs);
+	//m_wavecomponent.setBounds(1, yoffs, getWidth()-2, getHeight()-1-yoffs);
+	m_specvis.setBounds(1, yoffs, getWidth() - 2, getHeight() - 1 - yoffs);
 }
 
 void PaulstretchpluginAudioProcessorEditor::timerCallback(int id)
@@ -108,6 +110,12 @@ void PaulstretchpluginAudioProcessorEditor::timerCallback(int id)
 			m_wavecomponent.setAudioFile(processor.getAudioFile());
 		}
 		m_wavecomponent.setTimeSelection(processor.getTimeSelection());
+		
+	}
+	if (id == 3)
+	{
+		m_specvis.setState(processor.getStretchSource()->getProcessParameters(), processor.getStretchSource()->getFFTSize() / 2,
+			processor.getSampleRate());
 	}
 }
 
@@ -431,3 +439,55 @@ int WaveformComponent::getTimeSelectionEdge(int x, int y)
 	return 0;
 }
 
+SpectralVisualizer::SpectralVisualizer()
+{
+	m_img = Image(Image::RGB, 500, 200, true);
+}
+
+void SpectralVisualizer::setState(ProcessParameters & pars, int nfreqs, double samplerate)
+{
+	m_img = Image(Image::RGB, getWidth(), getHeight(), true);
+	std::vector<REALTYPE> insamples(nfreqs*2);
+	std::vector<REALTYPE> freqs1(nfreqs*2);
+	std::vector<REALTYPE> freqs2(nfreqs*2);
+	std::vector<REALTYPE> freqs3(nfreqs*2);
+	double hz = 440.0;
+	int numharmonics = 40;
+	double scaler = 1.0 / numharmonics;
+	for (int i = 0; i < nfreqs; ++i)
+	{
+		for (int j = 0; j < numharmonics; ++j)
+		{
+			double oscgain = 1.0 - (1.0 / numharmonics)*j;
+			insamples[i] += scaler * oscgain * sin(2 * 3.141592653 / samplerate * i* (hz+hz*j));
+		}
+	}
+	FFT fft(nfreqs*2);
+	for (int i = 0; i < nfreqs; ++i)
+	{
+		fft.smp[i] = insamples[i];
+	}
+	fft.applywindow(W_HAMMING);
+	fft.smp2freq();
+	double ratio = pow(2.0f, pars.pitch_shift.cents / 1200.0f);
+	spectrum_do_pitch_shift(pars, nfreqs, fft.freq.data(), freqs2.data(), ratio);
+	spectrum_do_freq_shift(pars, nfreqs, samplerate, freqs2.data(), freqs1.data());
+	spectrum_do_compressor(pars, nfreqs, freqs1.data(), freqs2.data());
+	spectrum_spread(nfreqs, samplerate, freqs3, freqs2.data(), freqs1.data(), pars.spread.bandwidth);
+	Graphics g(m_img);
+	g.setColour(Colours::white);
+	for (int i = 0; i < nfreqs; ++i)
+	{
+		double binfreq = (samplerate / 2 / nfreqs)*i;
+		double xcor = jmap<double>(binfreq, 0.0, samplerate / 2.0, 0.0, getWidth());
+		double ycor = getHeight()- jmap<double>(freqs1[i], 0.0, nfreqs/64, 0.0, getHeight());
+		ycor = jlimit<double>(0.0, getHeight(), ycor);
+		g.drawLine(xcor, getHeight(), xcor, ycor, 1.0);
+	}
+	repaint();
+}
+
+void SpectralVisualizer::paint(Graphics & g)
+{
+	g.drawImage(m_img, 0, 0, getWidth(), getHeight(), 0, 0, m_img.getWidth(), m_img.getHeight());
+}

Source/PluginEditor.h

@@ -15,6 +15,17 @@
 #include <memory>
 #include <vector>
 
+class SpectralVisualizer : public Component
+{
+public:
+	SpectralVisualizer();
+	void setState(ProcessParameters& pars, int nfreqs, double samplerate);
+	void paint(Graphics& g) override;
+	
+private:
+	Image m_img;
+};
+
 inline void attachCallback(Button& button, std::function<void()> callback)
 {
 	struct ButtonCallback : public Button::Listener,
@@ -240,6 +251,7 @@ public:
 private:
     PaulstretchpluginAudioProcessor& processor;
 	std::vector<std::shared_ptr<ParameterComponent>> m_parcomps;
+	SpectralVisualizer m_specvis;
 	ToggleButton m_rec_enable;
 	TextButton m_import_button;
 	Label m_info_label;