common/alcomplex.h

   1 #ifndef ALCOMPLEX_H
   2 #define ALCOMPLEX_H
   3
   4 #include "AL/al.h"
   5
   6
   7 #ifdef __cplusplus
   8 extern "C" {
   9 #endif
  10
  11 typedef struct ALcomplex {
  12     ALdouble Real;
  13     ALdouble Imag;
  14 } ALcomplex;
  15
  16 /** Addition of two complex numbers. */
  17 inline ALcomplex complex_add(ALcomplex a, ALcomplex b)
  18 {
  19     ALcomplex result;
  20
  21     result.Real = a.Real + b.Real;
  22     result.Imag = a.Imag + b.Imag;
  23
  24     return result;
  25 }
  26
  27 /** Subtraction of two complex numbers. */
  28 inline ALcomplex complex_sub(ALcomplex a, ALcomplex b)
  29 {
  30     ALcomplex result;
  31
  32     result.Real = a.Real - b.Real;
  33     result.Imag = a.Imag - b.Imag;
  34
  35     return result;
  36 }
  37
  38 /** Multiplication of two complex numbers. */
  39 inline ALcomplex complex_mult(ALcomplex a, ALcomplex b)
  40 {
  41     ALcomplex result;
  42
  43     result.Real = a.Real*b.Real - a.Imag*b.Imag;
  44     result.Imag = a.Imag*b.Real + a.Real*b.Imag;
  45
  46     return result;
  47 }
  48
  49 /**
  50  * Iterative implementation of 2-radix FFT (In-place algorithm). Sign = -1 is
  51  * FFT and 1 is iFFT (inverse). Fills FFTBuffer[0...FFTSize-1] with the
  52  * Discrete Fourier Transform (DFT) of the time domain data stored in
  53  * FFTBuffer[0...FFTSize-1]. FFTBuffer is an array of complex numbers, FFTSize
  54  * MUST BE power of two.
  55  */
  56 void complex_fft(ALcomplex *FFTBuffer, ALsizei FFTSize, ALdouble Sign);
  57
  58 /**
  59  * Calculate the complex helical sequence (discrete-time analytical signal) of
  60  * the given input using the discrete Hilbert transform (In-place algorithm).
  61  * Fills Buffer[0...size-1] with the discrete-time analytical signal stored in
  62  * Buffer[0...size-1]. Buffer is an array of complex numbers, size MUST BE
  63  * power of two.
  64  */
  65 void complex_hilbert(ALcomplex *Buffer, ALsizei size);
  66
  67 #ifdef __cplusplus
  68 } // extern "C"
  69 #endif
  70
  71 #endif /* ALCOMPLEX_H */