text: // Copyright 2013 Olivier Gillet.
  //
  // Author: Olivier Gillet (pichenettes@mutable-instruments.net)
  //
  // 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.
  //
  // -----------------------------------------------------------------------------
  //
  // Trigger to gate converter with pre-delay, duration, and repetitions.
  
  #include "peaks/pulse_processor/pulse_shaper.h"
  
  #include <algorithm>
  
  #include "stmlib/utils/dsp.h"
  
  #include "peaks/resources.h"
  
  namespace peaks {
  
  using namespace stmlib;
  
  void PulseShaper::Init() {
    initial_delay_ = 0;
    duration_ = 0;
    delay_ = 0;
    num_repetitions_ = 0;
  
    Pulse p;
    p.initial_delay_counter = 0;
    p.duration_counter = 0;
    p.delay_counter = 0;
    p.repetition_counter = 0;
    
    std::fill(&pulse_buffer_[0], &pulse_buffer_[kPulseBufferSize], p);
    
    previous_num_pulses_ = 0;
    retrig_counter_ = 0;
  }
  
  inline uint16_t PulseShaper::delay() const {
    return Interpolate88(lut_delay_times, delay_) - 1;
  }
  
  inline uint16_t PulseShaper::duration() const {
    return Interpolate88(lut_delay_times, duration_);
  }
  
  inline uint16_t PulseShaper::initial_delay() const {
    return Interpolate88(lut_delay_times, initial_delay_);
  }
  
  void PulseShaper::Process(
      const GateFlags* gate_flags, int16_t* out, size_t size) {
    bool new_pulse = false;
    for (size_t i = 0; i < size; ++i) {
      new_pulse |= gate_flags[i] & GATE_FLAG_RISING;
    }
      
    uint8_t num_pulses = 0;
    for (uint8_t i = 0; i < kPulseBufferSize; ++i) {
      Pulse& p = pulse_buffer_[i];
      if (p.repetition_counter) {
        // Handle the case when the duration of the pulse is larger than the
        // delay time. In this case, set the duration to just a sample below
        // the delay time.
        if (p.delay_counter < p.duration_counter && p.repetition_counter > 1) {
          p.duration_counter = p.delay_counter;
        }
        
        if (p.initial_delay_counter == 0) {
          if (p.duration_counter) {
            // ON
            --p.duration_counter;
            ++num_pulses;
          }
          if (p.delay_counter) {
            --p.delay_counter;
          } else {
            // Retrigger
            --p.repetition_counter;
            p.duration_counter = duration();
            p.delay_counter = delay();
          }
        } else {
          // Still in pre-delay phase...
          --p.initial_delay_counter;
        }
      } else {
        if (new_pulse) {
          p.repetition_counter = num_repetitions_ + 1;
          p.initial_delay_counter = initial_delay();
          p.duration_counter = duration();
          p.delay_counter = delay();
          new_pulse = false;
          num_pulses += p.initial_delay_counter ? 0 : 1;
        }
      }
    }
      
    // The output is already high, but a new pulse is arriving. Create
    // a short dip in the output to retrigger.
    if (previous_num_pulses_ && num_pulses > previous_num_pulses_) {
      retrig_counter_ = 6;
    }
    previous_num_pulses_ = num_pulses;
  
    if (retrig_counter_) {
      --retrig_counter_;
    }
    
    int16_t output = num_pulses > 0 && !retrig_counter_ ? 20480 : 0;
    std::fill(&out[0], &out[size], output);
  }
  
  }  // namespace peaks
  