comparison fft/nayukic/fft.h @ 33:bbf5d4e825eb

Hack in an alternative float-only version (no faster)

  * The vector's length must be a power of 2. Uses the Cooley-Tukey decimation-in-time radix-2 algorithm.
  * Returns 1 (true) if successful, 0 (false) otherwise (n is not a power of 2, or out of memory).
  */
 int transform_radix2(double real[], double imag[], size_t n);
 
+/* Test versions with precalculated structures -- this API is
+   absolutely not for production use! */
 typedef struct {
     double *cos;
     double *sin;
     int levels;
 } tables;
 
 tables *precalc(size_t n);
 void dispose(tables *);
 void transform_radix2_precalc(double real[], double imag[], int n, tables *tables);
+
+typedef struct {
+    float *cos;
+    float *sin;
+    int levels;
+} tables_f;
+
+tables_f *precalc_f(size_t n);
+void dispose_f(tables_f *);
+void transform_radix2_precalc_f(float real[], float imag[], int n, tables_f *tables);
 
 /* 
  * Computes the discrete Fourier transform (DFT) of the given complex vector, storing the result back into the vector.
  * The vector can have any length. This requires the convolution function, which in turn requires the radix-2 FFT function.
  * Uses Bluestein's chirp z-transform algorithm. Returns 1 (true) if successful, 0 (false) otherwise (out of memory).