Clean up some dead code and MSVC warnings.

- Dead code from experiments in SelectionBar removed.
- Many warnings about unused parameters fixed with WXUNUSED()
- Many warnings about signed / unsigned comparisons cleaned up.
- Several 'local variable declared but not used' warnings fixed.

src/Envelope.cpp

@@ -77,14 +77,14 @@ bool Envelope::ConsistencyCheck()
 
          while ( nextI - ii > 2 ) {
             // too many coincident time values
-            if (ii == mDragPoint || nextI - 1 == mDragPoint)
+            if (ii == (size_t)mDragPoint || (int)(nextI - 1) == mDragPoint)
                // forgivable
                ;
             else {
                consistent = false;
                // repair it
                Delete( nextI - 2 );
-               if (mDragPoint >= nextI - 2)
+               if (mDragPoint >= (int)(nextI - 2))
                   --mDragPoint;
                --nextI, --count;
                // wxLogError
@@ -167,7 +167,7 @@ void Envelope::SetDragPointValid(bool valid)
          mEnv[mDragPoint].SetVal( this, mDefaultValue );
          return;
       }
-      else if ( mDragPoint + 1 == size ) {
+      else if ( mDragPoint + 1 == (int)size ) {
          // Put the point at the height of the last point, but also off screen.
          mEnv[mDragPoint].SetT(big);
          mEnv[mDragPoint].SetVal( this, mEnv[ size - 1 ].GetVal() );
@@ -196,7 +196,7 @@ void Envelope::MoveDragPoint(double newWhen, double value)
 
    if (mDragPoint > 0)
       limitLo = std::max(limitLo, mEnv[mDragPoint - 1].GetT());
-   if (mDragPoint + 1 < mEnv.size())
+   if (mDragPoint + 1 < (int)mEnv.size())
       limitHi = std::min(limitHi, mEnv[mDragPoint + 1].GetT());
 
    EnvPoint &dragPoint = mEnv[mDragPoint];
@@ -272,8 +272,8 @@ Envelope::Envelope(const Envelope &orig)
 
 void Envelope::CopyRange(const Envelope &orig, size_t begin, size_t end)
 {
-   int len = orig.mEnv.size();
-   int i = begin;
+   size_t len = orig.mEnv.size();
+   size_t i = begin;
 
    // Create the point at 0 if it needs interpolated representation
    if ( i > 0 )
@@ -292,6 +292,7 @@ void Envelope::CopyRange(const Envelope &orig, size_t begin, size_t end)
       AddPointAtEnd( mTrackLen, orig.GetValue(mOffset + mTrackLen));
 }
 
+#if 0
 /// Limit() limits a double value to a range.
 /// TODO: Move to a general utilities source file.
 static double Limit( double Lo, double Value, double Hi )
@@ -302,6 +303,7 @@ static double Limit( double Lo, double Value, double Hi )
       return Hi;
    return Value;
 }
+#endif
 
 /// TODO: This should probably move to track artist.
 static void DrawPoint(wxDC & dc, const wxRect & r, int x, int y, bool top)
@@ -729,7 +731,7 @@ void Envelope::CollapseRegion( double t0, double t1, double sampleDur )
    auto len = mEnv.size();
    for ( size_t i = begin; i < len; ++i ) {
       auto &point = mEnv[i];
-      if (rightPoint && i == begin)
+      if (rightPoint && i == (size_t)begin)
          // Avoid roundoff error.
          // Make exactly equal times of neighboring points so that we have
          // a real discontinuity.
@@ -878,11 +880,11 @@ void Envelope::RemoveUnneededPoints
    // points removable?
 
    int index = startAt + ( rightward ? 1 : -1 );
-   while ( index >= 0 && index < len ) {
+   while ( index >= 0 && index < (int)len ) {
       // Stop at any discontinuity
       if ( index > 0       && isDiscontinuity( index - 1 ) )
          break;
-      if ( index + 1 < len && isDiscontinuity( index ) )
+      if ( (unsigned int)(index + 1) < len && isDiscontinuity( index ) )
          break;
 
       if ( ! remove( index, false ) )
@@ -915,7 +917,7 @@ std::pair< int, int > Envelope::ExpandRegion
 
    // Shift points.
    auto len = mEnv.size();
-   for ( int ii = index; ii < len; ++ii ) {
+   for ( unsigned int ii = index; ii < len; ++ii ) {
       auto &point = mEnv[ ii ];
       point.SetT( point.GetT() + tlen );
    }
@@ -1027,7 +1029,6 @@ int Envelope::InsertOrReplaceRelative(double when, double value)
    }
 #endif
 
-   int len = mEnv.size();
    when = std::max( 0.0, std::min( mTrackLen, when ) );
 
    auto range = EqualRange( when, 0 );
@@ -1135,9 +1136,9 @@ void Envelope::BinarySearchForTime( int &Lo, int &Hi, double t ) const
    // Optimizations for the usual pattern of repeated calls with
    // small increases of t.
    {
-      if (mSearchGuess >= 0 && mSearchGuess < mEnv.size()) {
+      if (mSearchGuess >= 0 && mSearchGuess < (int)mEnv.size()) {
          if (t >= mEnv[mSearchGuess].GetT() &&
-             (1 + mSearchGuess == mEnv.size() ||
+             (1 + mSearchGuess == (int)mEnv.size() ||
               t < mEnv[1 + mSearchGuess].GetT())) {
             Lo = mSearchGuess;
             Hi = 1 + mSearchGuess;
@@ -1146,9 +1147,9 @@ void Envelope::BinarySearchForTime( int &Lo, int &Hi, double t ) const
       }
 
       ++mSearchGuess;
-      if (mSearchGuess >= 0 && mSearchGuess < mEnv.size()) {
+      if (mSearchGuess >= 0 && mSearchGuess < (int)mEnv.size()) {
          if (t >= mEnv[mSearchGuess].GetT() &&
-             (1 + mSearchGuess == mEnv.size() ||
+             (1 + mSearchGuess == (int)mEnv.size() ||
               t < mEnv[1 + mSearchGuess].GetT())) {
             Lo = mSearchGuess;
             Hi = 1 + mSearchGuess;
@@ -1390,7 +1391,7 @@ double Envelope::NextPointAfter(double t) const
 {
    int lo,hi;
    BinarySearchForTime( lo, hi, t );
-   if (hi >= mEnv.size())
+   if (hi >= (int)mEnv.size())
       return t;
    else
       return mEnv[hi].GetT();
@@ -1705,7 +1706,7 @@ double Envelope::SolveIntegralOfInverse( double t0, double area ) const
          // loop through the rest of the envelope points until we get to t1
          while (1)
          {
-            if(i >= count) // the requested range extends beyond the last point
+            if(i >= (int)count) // the requested range extends beyond the last point
             {
                return lastT + area * lastVal;
             }