Move SpectrumAnalyst into its own files...

... It's the pure calculation common to the Plot Spectrum window and
to spectral editing

This removes some dependencies on FreqWindow

src/SpectrumAnalyst.h

@@ -0,0 +1,82 @@
+/**********************************************************************
+
+  Audacity: A Digital Audio Editor
+
+  SpectrumAnalyst.h
+
+  Dominic Mazzoni
+  Paul Licameli split from FreqWindow.h
+
+**********************************************************************/
+
+#ifndef __AUDACITY_SPECTRUM_ANALYST__
+#define __AUDACITY_SPECTRUM_ANALYST__
+
+#include <vector>
+#include <wx/statusbr.h>
+
+class FreqGauge;
+
+class SpectrumAnalyst
+{
+public:
+
+   enum Algorithm {
+      Spectrum,
+      Autocorrelation,
+      CubeRootAutocorrelation,
+      EnhancedAutocorrelation,
+      Cepstrum,
+
+      NumAlgorithms
+   };
+
+   SpectrumAnalyst();
+   ~SpectrumAnalyst();
+
+   // Return true iff successful
+   bool Calculate(Algorithm alg,
+      int windowFunc, // see FFT.h for values
+      size_t windowSize, double rate,
+      const float *data, size_t dataLen,
+      float *pYMin = NULL, float *pYMax = NULL, // outputs
+      FreqGauge *progress = NULL);
+
+   const float *GetProcessed() const;
+   int GetProcessedSize() const;
+
+   float GetProcessedValue(float freq0, float freq1) const;
+   float FindPeak(float xPos, float *pY) const;
+
+private:
+   float CubicInterpolate(float y0, float y1, float y2, float y3, float x) const;
+   float CubicMaximize(float y0, float y1, float y2, float y3, float * max) const;
+
+private:
+   Algorithm mAlg;
+   double mRate;
+   size_t mWindowSize;
+   std::vector<float> mProcessed;
+};
+
+class FreqGauge final : public wxStatusBar
+{
+public:
+   FreqGauge(wxWindow * parent, wxWindowID winid);
+
+   void SetRange(int range, int bar = 12, int gap = 3);
+   void SetValue(int value);
+   void Reset();
+
+private:
+   wxRect mRect;
+   int mRange;
+   int mCur;
+   int mLast;
+   int mInterval;
+   int mBar;
+   int mGap;
+   int mMargin;
+};
+
+#endif