variables.h

/* ScummVM - Graphic Adventure Engine
 *
 * ScummVM is the legal property of its developers, whose names
 * are too numerous to list here. Please refer to the COPYRIGHT
 * file distributed with this source distribution.
 *
 * 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/>.
 *
 *
 * This file is dual-licensed.
 * In addition to the GPLv3 license mentioned above, this code is also
 * licensed under LGPL 2.1. See LICENSES/COPYING.LGPL file for the
 * full text of the license.
 *
 */

#ifndef GOB_VARIABLES_H
#define GOB_VARIABLES_H

namespace Gob {

class Variables {
public:
    enum Type {
        kVariableType8,
        kVariableType16,
        kVariableType32
    };

    Variables(uint32 size);
    virtual ~Variables();

    uint32 getSize() const;

    void writeVar8(uint32 var, uint8 value);
    void writeVar16(uint32 var, uint16 value);
    void writeVar32(uint32 var, uint32 value);

    void writeVarString(uint32 var, const char *value);

    void writeOff8(uint32 offset, uint8 value);
    void writeOff16(uint32 offset, uint16 value);
    void writeOff32(uint32 offset, uint32 value);

    void writeOffString(uint32 offset, const char *value);

    uint8 readVar8(uint32 var) const;
    uint16 readVar16(uint32 var) const;
    uint32 readVar32(uint32 var) const;

    void readVarString(uint32 var, char *value, uint32 length);

    uint8 readOff8(uint32 offset) const;
    uint16 readOff16(uint32 offset) const;
    uint32 readOff32(uint32 offset) const;

    void readOffString(uint32 offset, char *value, uint32 length);


    const uint8 *getAddressVar8(uint32 var) const;
    uint8 *getAddressVar8(uint32 var);

    const char *getAddressVarString(uint32 var) const;
    char *getAddressVarString(uint32 var);

    const uint8 *getAddressOff8(uint32 offset) const;
    uint8 *getAddressOff8(uint32 offset);

    const char *getAddressOffString(uint32 offset) const;
    char *getAddressOffString(uint32 offset);


    bool copyTo(uint32 offset, byte *variables, uint32 n) const;
    bool copyFrom(uint32 offset, const byte *variables, uint32 n);

protected:
    virtual void write8(byte *buf, uint8 data) const = 0;
    virtual void write16(byte *buf, uint16 data) const = 0;
    virtual void write32(byte *buf, uint32 data) const = 0;

    virtual uint8 read8(const byte *buf) const = 0;
    virtual uint16 read16(const byte *buf) const = 0;
    virtual uint32 read32(const byte *buf) const = 0;

private:
    uint32 _size;
    byte *_vars;

    void clear();
};

class VariablesLE : public Variables {
public:
    VariablesLE(uint32 size);
    ~VariablesLE() override;

protected:
    void write8(byte *buf, uint8 data) const override;
    void write16(byte *buf, uint16 data) const override;
    void write32(byte *buf, uint32 data) const override;

    uint8 read8(const byte *buf) const override;
    uint16 read16(const byte *buf) const override;
    uint32 read32(const byte *buf) const override;
};

class VariablesBE : public Variables {
public:
    VariablesBE(uint32 size);
    ~VariablesBE() override;

protected:
    void write8(byte *buf, uint8 data) const override;
    void write16(byte *buf, uint16 data) const override;
    void write32(byte *buf, uint32 data) const override;

    uint8 read8(const byte *buf) const override;
    uint16 read16(const byte *buf) const override;
    uint32 read32(const byte *buf) const override;
};

class VariableReference {
public:
    VariableReference();
    VariableReference(Variables &vars, uint32 offset,
            Variables::Type type = Variables::kVariableType32);
    ~VariableReference();

    void set(Variables &vars, uint32 offset, Variables::Type type = Variables::kVariableType32);

    VariableReference &operator=(uint32 value);
    VariableReference &operator+=(uint32 value);
    VariableReference &operator*=(uint32 value);
    operator uint32();

private:
    Variables *_vars;
    uint32 _offset;
    Variables::Type _type;
};

class VariableStack {
public:
    VariableStack(uint32 size);
    ~VariableStack();

    void pushData(const Variables &vars, uint32 offset, uint32 size);
    void pushInt(uint32 value);

    void pop(Variables &vars, uint32 offset);

private:
    byte *_stack;

    uint32 _size;
    uint32 _position;
};

} // End of namespace Gob

#endif // GOB_VARIABLES_H