eurorack/pure_adsr/mini_sequencer.h

// Copyright 2013 Emilie Gillet.
//
// Author: Emilie Gillet (emilie.o.gillet@gmail.com)
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
//
// See http://creativecommons.org/licenses/MIT/ for more information.
//
// -----------------------------------------------------------------------------
//
// Mini sequencer.

#ifndef PEAKS_MODULATIONS_MINI_SEQUENCER_H_
#define PEAKS_MODULATIONS_MINI_SEQUENCER_H_

#include "pure_adsr/gate_processor.h"
#include <stddef.h>

#define abs(X) ((X) < 0 ? -(X) : (X))

namespace pure_adsr {

const uint8_t kMaxNumSteps = 4;

class MiniSequencer {
  public:
  MiniSequencer() {}
  ~MiniSequencer() {}

  void Init()
  {
    for (size_t i = 0; i < kMaxNumSteps; i++)
      steps_[i] = 0;
    num_steps_ = 4;
    step_ = 0;
    reset_at_next_clock_ = false;
  }

  inline void set_step(uint8_t index, int16_t value)
  {
    int32_t difference = abs(int32_t(steps_[index]) - value);
    if (difference > 0) {
      steps_[index] = value;
    }
  }

  inline void set_num_steps(uint8_t num_steps)
  {
    num_steps_ = num_steps;
  }

  void Configure(uint16_t* parameter, ControlMode control_mode)
  {
    set_step(0, parameter[0] >> 1);
    set_step(1, parameter[1] >> 1);
    set_step(2, parameter[2] >> 1);
    set_step(3, parameter[3] >> 1);
    set_num_steps(4);
  }

  void Process(const GateFlags* gate_flags, int16_t* out, size_t size)
  {
    while (size--) {
      GateFlags gate_flag = *gate_flags++;
      if (gate_flag & GATE_FLAG_RISING) {
        ++step_;
        if (reset_at_next_clock_) {
          reset_at_next_clock_ = false;
          step_ = 0;
        }
      }
      if (num_steps_ > 2 && gate_flag & GATE_FLAG_AUXILIARY_RISING) {
        reset_at_next_clock_ = true;
      }
      if (step_ >= num_steps_) {
        step_ = 0;
      }
      *out++ = static_cast<int32_t>(steps_[step_]) * 40960 >> 16;
    }
  }

  private:
  uint8_t num_steps_;
  uint8_t step_;
  int16_t steps_[kMaxNumSteps];

  bool reset_at_next_clock_;

  DISALLOW_COPY_AND_ASSIGN(MiniSequencer);
};

} // namespace peaks

#endif // PEAKS_MODULATIONS_MINI_SEQUENCER_H_