Improve formatting of the hilbert function

2 files changed, 35 insertions, 39 deletions

diff --git a/common/alcomplex.c b/common/alcomplex.c
index 9cf9d9bd..d4045aeb 100644
--- a/common/alcomplex.c
+++ b/common/alcomplex.c
@@ -60,37 +60,33 @@ void complex_fft(ALcomplex *FFTBuffer, ALsizei FFTSize, ALdouble Sign)
     }
 }
 
-/*Discrete Hilbert Transform (analytic signal form)*/
-void hilbert(ALsizei size, ALcomplex *InOutBuffer )

-{

-    ALsizei k;

-    const ALdouble inverse_size = 1.0/(ALdouble)size;

-

-    for ( k = 0; k < size;k++ ) 

-          InOutBuffer[k].Imag = 0.0;

-

-    complex_fft( InOutBuffer, size, 1.0 );

-

-    for( k = 0; k < size; k++ )

-    {

-        if( k == 0 || k == size/2 )

-        {

-            InOutBuffer[k].Real *= inverse_size;

-            InOutBuffer[k].Imag *= inverse_size;

-        }

-

-        else if ( k >=1 && k < size/2 )

-        {

-            InOutBuffer[k].Real *= 2.0*inverse_size;

-            InOutBuffer[k].Imag *= 2.0*inverse_size;

-        }

-

-        else

-        {

-            InOutBuffer[k].Real   = 0.0;

-            InOutBuffer[k].Imag   = 0.0;

-        }

-    }

-

-    complex_fft( InOutBuffer, size,-1.0 );

+void complex_hilbert(ALcomplex *Buffer, ALsizei size)
+{
+    const ALdouble inverse_size = 1.0/(ALdouble)size;
+    ALsizei todo, i;
+
+    for(i = 0;i < size;i++)
+        Buffer[i].Imag = 0.0;
+
+    complex_fft(Buffer, size, 1.0);
+
+    todo = size >> 1;
+    Buffer[0].Real *= inverse_size;
+    Buffer[0].Imag *= inverse_size;
+    for(i = 1;i < todo;i++)
+    {
+        Buffer[i].Real *= 2.0*inverse_size;
+        Buffer[i].Imag *= 2.0*inverse_size;
+    }
+    Buffer[i].Real *= inverse_size;
+    Buffer[i].Imag *= inverse_size;
+    i++;
+
+    for(;i < size;i++)
+    {
+        Buffer[i].Real = 0.0;
+        Buffer[i].Imag = 0.0;
+    }
+
+    complex_fft(Buffer, size, -1.0);
 }
diff --git a/common/alcomplex.h b/common/alcomplex.h
index cfd164b6..2418ce78 100644
--- a/common/alcomplex.h
+++ b/common/alcomplex.h
@@ -56,13 +56,13 @@ inline ALcomplex complex_mult(ALcomplex a, ALcomplex b)
 void complex_fft(ALcomplex *FFTBuffer, ALsizei FFTSize, ALdouble Sign);
 
 /**
- *Calculate the complex helical sequence (or discrete-time analytical signal)
- *of the given input using the discrete Hilbert transform (In-place algorithm).
- *Fills InOutBuffer[0...size-1] with the discrete-time analytical signal stored 
- *in InOutBuffer[0...size-1]. InOutBuffer is an array of complex numbers, 
- *size MUST BE power of two.
+ * Calculate the complex helical sequence (discrete-time analytical signal) of
+ * the given input using the discrete Hilbert transform (In-place algorithm).
+ * Fills Buffer[0...size-1] with the discrete-time analytical signal stored in
+ * Buffer[0...size-1]. Buffer is an array of complex numbers, size MUST BE
+ * power of two.
  */
-void hilbert(ALsizei size, ALcomplex *InOutBuffer );
+void complex_hilbert(ALcomplex *Buffer, ALsizei size);
 
 #ifdef __cplusplus
 } // extern "C"