midipal

// Copyright 2011 Emilie Gillet.
//
// Author: Emilie Gillet (emilie.o.gillet@gmail.com)
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.
//
// -----------------------------------------------------------------------------
//
// Event list. I apologize for not using a smarter data structure - the
// insertion of an item in the queue is O(n) while it should be O(log n).

#ifndef MIDIPAL_EVENT_SCHEDULER_H_
#define MIDIPAL_EVENT_SCHEDULER_H_

#include "avrlib/base.h"

namespace midipal {

#ifdef POLY_SEQUENCER_FIRMWARE
static const uint8_t kEventSchedulerSize = 4;
#else
static const uint8_t kEventSchedulerSize = 90;
#endif  // POLY_SEQUENCER_FIRMWARE

static const uint8_t kFreeSlot = 0xff;
static const uint8_t kZombieSlot = 0xfe;

struct SchedulerEntry {
  uint8_t note;  // 0xff for free slot
  uint8_t velocity;  // 0 for note off
  uint8_t when;
  uint8_t next;
  uint8_t tag;
};

class EventScheduler {
 public:
  EventScheduler() { }
  
  static void Init();
  static void Tick();
  static void Schedule(uint8_t note, uint8_t velocity, uint8_t when, uint8_t tag);
  static void Schedule(uint8_t note, uint8_t velocity, uint8_t when) {
    Schedule(note, velocity, when, 0);
  }
  static uint8_t Remove(uint8_t note, uint8_t velocity);
  
  static inline const SchedulerEntry& entry(uint8_t address) {
    return entries_[address];
  }
  static inline const uint8_t root() { return root_ptr_; }
  static inline const uint8_t size() { return size_; }
  static inline const uint8_t overflow() {
    return size() >= kEventSchedulerSize - 8;
  }

 private:
  static SchedulerEntry entries_[kEventSchedulerSize];
  static uint8_t root_ptr_;
  static uint8_t size_;
  
  DISALLOW_COPY_AND_ASSIGN(EventScheduler);
};

extern EventScheduler event_scheduler;

}  // namespace midipal:

#endif // MIDIPAL_EVENT_SCHEDULER_H_