alex

/* *****************************************************************************
 * The method lives() is based on Xitari's code, from Google Inc.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License version 2
 * as published by the Free Software Foundation.
 *
 * 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, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 * *****************************************************************************
 * A.L.E (Arcade Learning Environment)
 * Copyright (c) 2009-2013 by Yavar Naddaf, Joel Veness, Marc G. Bellemare and
 *   the Reinforcement Learning and Artificial Intelligence Laboratory
 * Released under the GNU General Public License; see License.txt for details.
 *
 * Based on: Stella  --  "An Atari 2600 VCS Emulator"
 * Copyright (c) 1995-2007 by Bradford W. Mott and the Stella team
 *
 * *****************************************************************************
 */

#include "QBert.hpp"

#include "../RomUtils.hpp"

namespace ale {

QBertSettings::QBertSettings() { reset(); }

/* create a new instance of the rom */
RomSettings* QBertSettings::clone() const {
  return new QBertSettings(*this);
}

/* process the latest information from ALE */
void QBertSettings::step(const System& system) {
  // update terminal status
  int lives_value = readRam(&system, 0x88);
  // Lives start at 2 (4 lives, 3 displayed) and go down to 0xFE (death)
  // Alternatively we can die and reset within one frame; we catch this case
  m_terminal =
      (lives_value == 0xFE) || (lives_value == 0x02 && m_last_lives == -1);

  // Convert char into a signed integer
  int livesAsChar = static_cast<char>(lives_value);

  if (m_last_lives - 1 == livesAsChar)
    m_lives--;
  m_last_lives = livesAsChar;

  // update the reward
  // Ignore reward if reset the game via the fire button; otherwise the agent
  //  gets a big negative reward on its last step
  if (!m_terminal) {
    int score = getDecimalScore(0xDB, 0xDA, 0xD9, &system);
    int reward = score - m_score;
    m_reward = reward;
    m_score = score;
  } else {
    m_reward = 0;
  }
}

/* is end of game */
bool QBertSettings::isTerminal() const { return m_terminal; };

/* get the most recently observed reward */
reward_t QBertSettings::getReward() const { return m_reward; }

/* is an action part of the minimal set? */
bool QBertSettings::isMinimal(const Action& a) const {
  switch (a) {
    case PLAYER_A_NOOP:
    case PLAYER_A_FIRE:
    case PLAYER_A_UP:
    case PLAYER_A_RIGHT:
    case PLAYER_A_LEFT:
    case PLAYER_A_DOWN:
      return true;
    default:
      return false;
  }
}

/* reset the state of the game */
void QBertSettings::reset() {
  m_reward = 0;
  m_score = 0;
  m_terminal = false;
  // Anything non-0xFF
  m_last_lives = 2;
  m_lives = 4;
}

/* saves the state of the rom settings */
void QBertSettings::saveState(Serializer& ser) {
  ser.putInt(m_reward);
  ser.putInt(m_score);
  ser.putBool(m_terminal);
  ser.putInt(m_last_lives);
  ser.putInt(m_lives);
}

// loads the state of the rom settings
void QBertSettings::loadState(Deserializer& ser) {
  m_reward = ser.getInt();
  m_score = ser.getInt();
  m_terminal = ser.getBool();
  m_last_lives = ser.getInt();
  m_lives = ser.getInt();
}

DifficultyVect QBertSettings::getAvailableDifficulties() {
  return {0, 1};
}

}  // namespace ale