ale-sys 0.1.2

Rust bindings to the Arcade Learning Environment
Documentation 
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/* *****************************************************************************
 * 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 "Skiing.hpp"

#include "../RomUtils.hpp"

namespace ale {

SkiingSettings::SkiingSettings() { reset(); }

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

/* process the latest information from ALE */
void SkiingSettings::step(const System& system) {
  // update the reward
  int centiseconds = getDecimalScore(0xEA, 0xE9, &system);
  int minutes = readRam(&system, 0xE8);
  int score = minutes * 6000 + centiseconds;
  int reward = m_score - score; // negative reward for time
  m_reward = reward;
  m_score = score;

  // update terminal status
  int end_flag = readRam(&system, 0x91);
  m_terminal = end_flag == 0xFF;
}

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

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

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

bool SkiingSettings::isLegal(const Action& a) const {
  switch (a) {
    // Don't allow pressing 'fire'
    case PLAYER_A_FIRE:
    case PLAYER_A_UPFIRE:
    case PLAYER_A_DOWNFIRE:
    case PLAYER_A_LEFTFIRE:
    case PLAYER_A_RIGHTFIRE:
    case PLAYER_A_UPLEFTFIRE:
    case PLAYER_A_UPRIGHTFIRE:
    case PLAYER_A_DOWNLEFTFIRE:
    case PLAYER_A_DOWNRIGHTFIRE:
      return false;
    default:
      return true;
  }
}

/* reset the state of the game */
void SkiingSettings::reset() {
  m_reward = 0;
  m_score = 0;
  m_terminal = false;
}

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

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

ActionVect SkiingSettings::getStartingActions() {
  ActionVect startingActions;
  for (int i = 0; i < 16; i++)
    startingActions.push_back(PLAYER_A_DOWN);
  return startingActions;
}

}  // namespace ale