Paul Licameli's Spectral Editing Patch.

This relies on three new nyquist scripts to actually do the editing.  The peak-snapping code in FrequencyWindow has been extracted into a new class, SpectrumAnalyst, to provide peak-snapping in spectrogram too.

src/SelectedRegion.h

@@ -6,26 +6,52 @@
 
   Dominic Mazzoni
 
+*******************************************************************//**
+
+\class SelectedRegion
+\brief Defines a selected portion of a project
+
+  This includes starting and ending times, and other optional information
+  such as a frequency range, but not the set of selected tracks.
+
+  Maintains the invariants that ending time is not less than starting time
+  and that starting and ending frequencies, when both defined, are also
+  correctly ordered.
+
+*//****************************************************************//**
+
 **********************************************************************/
 
 #ifndef __AUDACITY_SELECTEDREGION__
 #define __AUDACITY_SELECTEDREGION__
 
 #include "Audacity.h"
+#include "Experimental.h"
 
 class AUDACITY_DLL_API SelectedRegion {
 
    // Maintains the invariant:  t1() >= t0()
 
 public:
+
+   static const int UndefinedFrequency = -1;
+
    SelectedRegion()
       : mT0(0.0)
       , mT1(0.0)
+#ifdef EXPERIMENTAL_SPECTRAL_EDITING
+      , mF0(UndefinedFrequency)
+      , mF1(UndefinedFrequency)
+#endif
    {}
 
    SelectedRegion(double t0, double t1)
       : mT0(t0)
       , mT1(t1)
+#ifdef EXPERIMENTAL_SPECTRAL_EDITING
+      , mF0(UndefinedFrequency)
+      , mF1(UndefinedFrequency)
+#endif
    { ensureOrdering(); }
 
 
@@ -37,6 +63,10 @@ public:
    SelectedRegion(const SelectedRegion &x)
       : mT0(x.mT0)
       , mT1(x.mT1)
+#ifdef EXPERIMENTAL_SPECTRAL_EDITING
+      , mF0(x.mF0)
+      , mF1(x.mF1)
+#endif
    {}
 
    SelectedRegion& operator=(const SelectedRegion& x)
@@ -44,15 +74,34 @@ public:
       if (this != &x) {
          mT0 = x.mT0;
          mT1 = x.mT1;
+#ifdef EXPERIMENTAL_SPECTRAL_EDITING
+         mF0 = x.mF0;
+         mF1 = x.mF1;
+#endif
       }
       return *this;
    }
 
+   // Accessors
+
    double t0() const { return mT0; }
    double t1() const { return mT1; }
    double duration() const { return mT1 - mT0; }
    bool isPoint() const { return mT1 <= mT0; }
 
+#ifdef EXPERIMENTAL_SPECTRAL_EDITING
+   double f0() const { return mF0; }
+   double f1() const { return mF1; }
+   double fc() const {
+      if (mF0 == UndefinedFrequency ||
+          mF1 == UndefinedFrequency)
+          return UndefinedFrequency;
+      else
+         return sqrt(mF0 * mF1);
+   };
+#endif
+
+   // Mutators
    // PRL: to do: more integrity checks
 
    // Returns true iff the bounds got swapped
@@ -105,6 +154,28 @@ public:
 
    void collapseToT1() { mT0 = mT1; }
 
+#ifdef EXPERIMENTAL_SPECTRAL_EDITING
+   // Returns true iff the bounds got swapped
+   bool setF0(double f) {
+      mF0 = f;
+      return ensureFrequencyOrdering();
+   }
+
+   // Returns true iff the bounds got swapped
+   bool setF1(double f) {
+      mF1 = f;
+      return ensureFrequencyOrdering();
+   }
+
+   // Returns true iff the bounds got swapped
+   bool setFrequencies(double f0, double f1)
+   {
+      mF0 = f0;
+      mF1 = f1;
+      return ensureFrequencyOrdering();
+   }
+#endif
+
 private:
    bool ensureOrdering() 
    {
@@ -118,8 +189,33 @@ private:
          return false;
    }
 
+#ifdef EXPERIMENTAL_SPECTRAL_EDITING
+   bool ensureFrequencyOrdering()
+   {
+      if (mF1 < 0)
+         mF1 = UndefinedFrequency;
+      if (mF0 < 0)
+         mF0 = UndefinedFrequency;
+
+      if (mF0 != UndefinedFrequency &&
+          mF1 != UndefinedFrequency &&
+          mF1 < mF0) {
+         const double t = mF1;
+         mF1 = mF0;
+         mF0 = t;
+         return true;
+      }
+      else
+         return false;
+   }
+#endif
+
    double mT0;
    double mT1;
+#ifdef EXPERIMENTAL_SPECTRAL_EDITING
+   double mF0; // low frequency
+   double mF1; // high frequency
+#endif
 
 };