libs/audiographer/audiographer/routines.h

   1 #ifndef AUDIOGRAPHER_ROUTINES_H
   2 #define AUDIOGRAPHER_ROUTINES_H
   3
   4 #include "types.h"
   5
   6 #include <cmath>
   7
   8 #include "audiographer/visibility.h"
   9
  10 namespace AudioGrapher
  11 {
  12
  13 /// Allows overriding some routines with more efficient ones.
  14 class LIBAUDIOGRAPHER_API Routines
  15 {
  16   public:
  17         typedef uint32_t uint_type;
  18
  19         typedef float (*compute_peak_t)          (float const *, uint_type, float);
  20         typedef void  (*apply_gain_to_buffer_t)  (float *, uint_type, float);
  21
  22         static void override_compute_peak         (compute_peak_t func)         { _compute_peak = func; }
  23         static void override_apply_gain_to_buffer (apply_gain_to_buffer_t func) { _apply_gain_to_buffer = func; }
  24
  25         /** Computes peak in float buffer
  26           * \n RT safe
  27           * \param data buffer from which the peak is computed
  28           * \param frames length of the portion of \a buffer that is checked
  29           * \param current_peak current peak of buffer, if calculated in several passes
  30           * \return maximum of values in [\a data, \a data + \a frames) and \a current_peak
  31           */
  32         static inline float compute_peak (float const * data, uint_type frames, float current_peak)
  33         {
  34                 return (*_compute_peak) (data, frames, current_peak);
  35         }
  36
  37         /** Applies constant gain to buffer
  38          * \n RT safe
  39          * \param data data to which the gain is applied
  40          * \param frames length of data
  41          * \param gain gain that is applied
  42          */
  43         static inline void apply_gain_to_buffer (float * data, uint_type frames, float gain)
  44         {
  45                 (*_apply_gain_to_buffer) (data, frames, gain);
  46         }
  47
  48   private:
  49         static inline float default_compute_peak (float const * data, uint_type frames, float current_peak)
  50         {
  51                 for (uint_type i = 0; i < frames; ++i) {
  52                         float abs = std::fabs(data[i]);
  53                         if (abs > current_peak) { current_peak = abs; }
  54                 }
  55                 return current_peak;
  56         }
  57
  58         static inline void default_apply_gain_to_buffer (float * data, uint_type frames, float gain)
  59         {
  60                 for (uint_type i = 0; i < frames; ++i) {
  61                         data[i] *= gain;
  62                 }
  63         }
  64
  65         static compute_peak_t          _compute_peak;
  66         static apply_gain_to_buffer_t  _apply_gain_to_buffer;
  67 };
  68
  69 } // namespace
  70
  71 #endif // AUDIOGRAPHER_ROUTINES_H