Added zoom and pan plus fix for bug #884

It started out as just the fix for #884, but it went
a bit further.  Steve had the idea for the zoom and
pan addition, so I added it while I was working on

Author: lllucius

src/FFT.cpp

@@ -484,32 +484,32 @@ void PowerSpectrum(int NumSamples, float *In, float *Out)
 
 int NumWindowFuncs()
 {
-   return 10;
+   return eWinFuncCount;
 }
 
 const wxChar *WindowFuncName(int whichFunction)
 {
    switch (whichFunction) {
    default:
-   case 0:
+   case eWinFuncRectangular:
       return _("Rectangular");
-   case 1:
+   case eWinFuncBartlett:
       return wxT("Bartlett");
-   case 2:
+   case eWinFuncHamming:
       return wxT("Hamming");
-   case 3:
+   case eWinFuncHanning:
       return wxT("Hanning");
-   case 4:
+   case eWinFuncBlackman:
       return wxT("Blackman");
-   case 5:
+   case eWinFuncBlackmanHarris:
       return wxT("Blackman-Harris");
-   case 6:
+   case eWinFuncWelch:
       return wxT("Welch");
-   case 7:
+   case eWinFuncGaussian25:
       return wxT("Gaussian(a=2.5)");
-   case 8:
+   case eWinFuncGaussian35:
       return wxT("Gaussian(a=3.5)");
-   case 9:
+   case eWinFuncGaussian45:
       return wxT("Gaussian(a=4.5)");
    }
 }
@@ -521,43 +521,48 @@ void WindowFunc(int whichFunction, int NumSamples, float *in)
 
    switch( whichFunction )
    {
-   case 1:
+   default:
+      fprintf(stderr,"FFT::WindowFunc - Invalid window function: %d\n",whichFunction);
+      break;
+   case eWinFuncRectangular:
+      break;
+   case eWinFuncBartlett:
       // Bartlett (triangular) window
       for (i = 0; i < NumSamples / 2; i++) {
          in[i] *= (i / (float) (NumSamples / 2));
          in[i + (NumSamples / 2)] *=
              (1.0 - (i / (float) (NumSamples / 2)));
       }
       break;
-   case 2:
+   case eWinFuncHamming:
       // Hamming
       for (i = 0; i < NumSamples; i++)
          in[i] *= 0.54 - 0.46 * cos(2 * M_PI * i / (NumSamples - 1));
       break;
-   case 3:
+   case eWinFuncHanning:
       // Hanning
       for (i = 0; i < NumSamples; i++)
          in[i] *= 0.50 - 0.50 * cos(2 * M_PI * i / (NumSamples - 1));
       break;
-   case 4:
+   case eWinFuncBlackman:
       // Blackman
       for (i = 0; i < NumSamples; i++) {
           in[i] *= 0.42 - 0.5 * cos (2 * M_PI * i / (NumSamples - 1)) + 0.08 * cos (4 * M_PI * i / (NumSamples - 1));
       }
       break;
-   case 5:
+   case eWinFuncBlackmanHarris:
       // Blackman-Harris
       for (i = 0; i < NumSamples; i++) {
           in[i] *= 0.35875 - 0.48829 * cos(2 * M_PI * i /(NumSamples-1)) + 0.14128 * cos(4 * M_PI * i/(NumSamples-1)) - 0.01168 * cos(6 * M_PI * i/(NumSamples-1));
       }
       break;
-   case 6:
+   case eWinFuncWelch:
       // Welch
       for (i = 0; i < NumSamples; i++) {
           in[i] *= 4*i/(float)NumSamples*(1-(i/(float)NumSamples));
       }
       break;
-   case 7:
+   case eWinFuncGaussian25:
       // Gaussian (a=2.5)
       // Precalculate some values, and simplify the fmla to try and reduce overhead
       A=-2*2.5*2.5;
@@ -569,15 +574,15 @@ void WindowFunc(int whichFunction, int NumSamples, float *in)
           in[i] *= exp(A*(0.25 + ((i/(float)NumSamples)*(i/(float)NumSamples)) - (i/(float)NumSamples)));
       }
       break;
-   case 8:
+   case eWinFuncGaussian35:
       // Gaussian (a=3.5)
       A=-2*3.5*3.5;
       for (i = 0; i < NumSamples; i++) {
           // reduced
           in[i] *= exp(A*(0.25 + ((i/(float)NumSamples)*(i/(float)NumSamples)) - (i/(float)NumSamples)));
       }
       break;
-   case 9:
+   case eWinFuncGaussian45:
       // Gaussian (a=4.5)
       A=-2*4.5*4.5;
 
@@ -586,7 +591,5 @@ void WindowFunc(int whichFunction, int NumSamples, float *in)
           in[i] *= exp(A*(0.25 + ((i/(float)NumSamples)*(i/(float)NumSamples)) - (i/(float)NumSamples)));
       }
       break;
-   default:
-      fprintf(stderr,"FFT::WindowFunc - Invalid window function: %d\n",whichFunction);
    }
 }

src/FFT.h

@@ -29,6 +29,9 @@
   you need to use doubles.
 
 **********************************************************************/
+#ifndef __AUDACITY_FFT_H__
+#define __AUDACITY_FFT_H__
+
 /*
   Salvo Ventura - November 2006
   Added more window functions:
@@ -102,6 +105,21 @@ void FFT(int NumSamples,
  * 9: Gaussian(a=4.5)
  */
 
+enum eWindowFunctions
+{
+   eWinFuncRectangular,
+   eWinFuncBartlett,
+   eWinFuncHamming,
+   eWinFuncHanning,
+   eWinFuncBlackman,
+   eWinFuncBlackmanHarris,
+   eWinFuncWelch,
+   eWinFuncGaussian25,
+   eWinFuncGaussian35,
+   eWinFuncGaussian45,
+   eWinFuncCount
+};
+
 void WindowFunc(int whichFunction, int NumSamples, float *data);
 
 /*
@@ -117,3 +135,5 @@ const wxChar *WindowFuncName(int whichFunction);
 int NumWindowFuncs();
 
 void DeinitFFT();
+
+#endif