Loopp/src/metronome.cxx

#include "metronome.hxx"

#include <cmath>
#include <iostream>

#include "jack.hxx"
#include "buffers.hxx"
#include "observer/time.hxx"

extern Jack* jack;

using namespace std;

Metronome::Metronome() :
  TimeObserver(),
  playBar    (false),
  active     (false),
  playPoint  (0)
{
  // create beat and bar samples
  endPoint = ( jack->getSamplerate() / 441 );
  // samples per cycle of 
  float scale = 2 * 3.1415 / endPoint;
  
  // And fill it up
  for(int i=0;i < endPoint*40;i++){
    beatSample[i]= sin(i*scale);
    barSample [i]= sin(i*scale*1.5);
  }
  
  // don't play after creation
  playPoint = endPoint + 1;
}

void Metronome::setActive(bool a)
{
  active = a;
  // don't play immidiatly
  playPoint = endPoint + 1;
}

void Metronome::bar(int)
{
  playPoint = 0;
  playBar = true;
}

void Metronome::beat()
{
  playPoint = 0;
}

void Metronome::setFpb(int f)
{
  fpb = f;
  
  // disable play until next beat
  playPoint = endPoint + 1;
}

void Metronome::process(int nframes, Buffers* buffers)
{
  if ( not active )
    return;
  
  float* outL = buffers->audio[Buffers::MASTER_OUT_L];
  float* outR = buffers->audio[Buffers::MASTER_OUT_R];
  
  float* sample = &beatSample[0];
  if( playBar ) { sample = &barSample[0]; playBar = false; }
  
  for(int i = 0; i < nframes; i++)
  {
    if ( playPoint < endPoint )
    {
      outL[i] += sample[playPoint];
      outR[i] += sample[playPoint];
      playPoint++;
    }
  }
}