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/* *****************************************************************************
* 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 "SpaceInvaders.hpp"
#include "../RomUtils.hpp"
namespace ale {
ActionVect SpaceInvadersSettings::actions;
SpaceInvadersSettings::SpaceInvadersSettings() { reset(); }
/* create a new instance of the rom */
RomSettings* SpaceInvadersSettings::clone() const {
RomSettings* rval = new SpaceInvadersSettings();
*rval = *this;
return rval;
}
/* process the latest information from ALE */
void SpaceInvadersSettings::step(const System& system) {
// update the reward
int score = getDecimalScore(0xE8, 0xE6, &system);
// reward cannot get negative in this game. When it does, it means that the score has looped
// (overflow)
m_reward = score - m_score;
if (m_reward < 0) {
// 10000 is the highest possible score
const int maximumScore = 10000;
m_reward = (maximumScore - m_score) + score;
}
m_score = score;
m_lives = readRam(&system, 0xC9);
// update terminal status
// If bit 0x80 is on, then game is over
int some_byte = readRam(&system, 0x98);
m_terminal = (some_byte & 0x80) || m_lives == 0;
}
/* is end of game */
bool SpaceInvadersSettings::isTerminal() const { return m_terminal; };
/* get the most recently observed reward */
reward_t SpaceInvadersSettings::getReward() const { return m_reward; }
/* is an action part of the minimal set? */
bool SpaceInvadersSettings::isMinimal(const Action& a) const {
switch (a) {
case PLAYER_A_NOOP:
case PLAYER_A_LEFT:
case PLAYER_A_RIGHT:
case PLAYER_A_FIRE:
case PLAYER_A_LEFTFIRE:
case PLAYER_A_RIGHTFIRE:
return true;
default:
return false;
}
}
/* reset the state of the game */
void SpaceInvadersSettings::reset() {
m_reward = 0;
m_score = 0;
m_terminal = false;
m_lives = 3;
}
/* saves the state of the rom settings */
void SpaceInvadersSettings::saveState(Serializer& ser) {
ser.putInt(m_reward);
ser.putInt(m_score);
ser.putBool(m_terminal);
ser.putInt(m_lives);
}
// loads the state of the rom settings
void SpaceInvadersSettings::loadState(Deserializer& ser) {
m_reward = ser.getInt();
m_score = ser.getInt();
m_terminal = ser.getBool();
m_lives = ser.getInt();
}
// returns a list of mode that the game can be played in
ModeVect SpaceInvadersSettings::getAvailableModes() {
ModeVect modes(getNumModes());
for (unsigned int i = 0; i < modes.size(); i++) {
modes[i] = i;
}
return modes;
}
// set the mode of the game
// the given mode must be one returned by the previous function
void SpaceInvadersSettings::setMode(
game_mode_t m, System& system,
std::unique_ptr<StellaEnvironmentWrapper> environment) {
if (m < getNumModes()) {
// read the mode we are currently in
unsigned char mode = readRam(&system, 0xDC);
// press select until the correct mode is reached
while (mode != m) {
environment->pressSelect(2);
mode = readRam(&system, 0xDC);
}
//reset the environment to apply changes.
environment->softReset();
} else {
throw std::runtime_error("This mode doesn't currently exist for this game");
}
}
DifficultyVect SpaceInvadersSettings::getAvailableDifficulties() {
DifficultyVect diff = {0, 1};
return diff;
}
} // namespace ale