internal checkpoint

split kiss_fft.c into multiple files.  It seems the best approach, all things considered.

kiss_fft.h

@@ -1,6 +1,12 @@
 #ifndef KISS_FFT_H
 #define KISS_FFT_H
 
+#include <stdlib.h>
+#include <stdio.h>
+#include <math.h>
+#include <memory.h>
+
+
 #ifdef FIXED_POINT
 # define kiss_fft_scalar short
 #else
@@ -31,22 +37,27 @@ void* kiss_fft_alloc(int nfft,int inverse_fft);
 /*
  * kiss_fft(cfg,in_out_buf)
  *
- * Perform an in-place FFT on a complex input buffer.
+ * Perform an FFT on a complex input buffer.
  * for a forward FFT,
- * the input should be  f[0] , f[1] , ... ,f[nfft-1]
- * the output will be   F[0] , F[1] , ... ,F[nfft-1]
- * Note that each element is complex.
- * */
-void kiss_fft( const void* cfg_from_alloc , kiss_fft_cpx *f ); /* call for each buffer */
+ * fin should be  f[0] , f[1] , ... ,f[nfft-1]
+ * fout will be   F[0] , F[1] , ... ,F[nfft-1]
+ * Note that each element is complex and can be accessed like
+    f[k].r and f[k].i
+
+   Apologies to previous users of KISS FFT, this function has changed from 2 args to 3 args.
+   To maintain the original behavior , use fout == fin 
+ * */
+
+void kiss_fft(const void * cfg,const kiss_fft_cpx *fin,kiss_fft_cpx *fout);
 
-/* two buffer version */
-void kiss_fft_io(const void * cfg,const kiss_fft_cpx *fin,kiss_fft_cpx *fout);
 
 /* allocate a 2-dimensional FFT
-   kiss_fft() is used as in the 1d case, but the data should be stored rowwise,
+   the data should be stored rowwise,
    in other words, an array made up of row[0], then row[1], etc
  */
 void * kiss_fft2d_alloc(int nrows,int ncols,int inverse_fft);
+void kiss_fft2d(const void* cfg_from_alloc , const kiss_fft_cpx *fin,kiss_fft_cpx *fout );
+
 
 /* when done with the cfg for a given fft size and direction, simply free it*/
 #define kiss_fft_free free