ale-sys 0.1.2

/* *****************************************************************************
 * 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
 *
 * *****************************************************************************
 *  ale_ram.hpp
 *
 *  A class that encapsulates the Atari 2600 RAM. Code is provided inline for
 *   efficiency reasonss.
 *
 **************************************************************************** */

#ifndef __ALE_RAM_HPP__
#define __ALE_RAM_HPP__

#include <cstring>

namespace ale {

using byte_t = unsigned char;

#define RAM_SIZE (128)

/** A simple wrapper around the Atari RAM. */
class ALERAM {
 public:
  ALERAM();
  ALERAM(const ALERAM& rhs);

  ALERAM& operator=(const ALERAM& rhs);

  /** Byte accessors */
  byte_t get(unsigned int x) const;
  byte_t* byte(unsigned int x);

  /** Returns the whole array (equivalent to byte(0)). */
  byte_t* array() const { return (byte_t*)(m_ram); }

  size_t size() const { return sizeof(m_ram); }
  /** Returns whether two copies of the RAM are equal */
  bool equals(const ALERAM& rhs) const;

 protected:
  byte_t m_ram[RAM_SIZE];
};

inline ALERAM::ALERAM() {}

inline ALERAM::ALERAM(const ALERAM& rhs) {
  // Copy data over
  memcpy(m_ram, rhs.m_ram, sizeof(m_ram));
}

inline ALERAM& ALERAM::operator=(const ALERAM& rhs) {
  // Copy data over
  memcpy(m_ram, rhs.m_ram, sizeof(m_ram));

  return *this;
}

inline bool ALERAM::equals(const ALERAM& rhs) const {
  return (memcmp(m_ram, rhs.m_ram, size()) == 0);
}

// Byte accessors
inline byte_t ALERAM::get(unsigned int x) const {
  // Wrap RAM around the first 128 bytes
  return m_ram[x & 0x7F];
}

inline byte_t* ALERAM::byte(unsigned int x) { return &m_ram[x & 0x7F]; }

}  // namespace ale

#endif  // __ALE_RAM_HPP__