score-avnd-senior/Ottobit/OttobitModel.cpp

#include <Gamma/scl.h>

#include "Ottobit.hpp"

namespace Meris
{
void Ottobit::operator()(tick t)
{
  // Only compute bit_factor when the control changes
  if (inputs.bits != previous_bits)
  {
    set_bit_factor();
    previous_bits = inputs.bits;
  }

  // Only compute skipped_frames when the control changes
  if (inputs.rate != previous_rate)
  {
    step_size = (1. - inputs.rate) * RATE;
    previous_rate = inputs.rate;
  }

  // Process the input buffer
  for(int i{0}; i < inputs.audio.channels; i++)
  {
    auto* in = inputs.audio[i];
    auto* out = outputs.audio[i];

    // Init current_frame for each channel
    double current_frame{crush_frame(in[0])};

    for(int j{0}; j < t.frames; j++)
    {
      if (skipped_frames[i] <= step_size)
        skipped_frames[i]++;
      else
      {
        skipped_frames[i] = 0;
        current_frame = crush_frame(in[j]);
      }

      out[j] = current_frame;
    }
  }
}

void Ottobit::set_bit_factor()
{
  bit_factor = pow(2, inputs.bits) - 1;
}

double Ottobit::crush_frame(const double& f)
{
  if (inputs.bits == BITS)
    return f;
  else
  {
    // Rounding using static_cast
    // return static_cast<double>(static_cast<int>(f * bit_factor)) / bit_factor;
    // Close, but prefer Lance Putnama's Gama's use of roundMagic
    return gam::scl::round<double>(f * bit_factor) / bit_factor;
  }
}
}