script.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_SCRIPT_H
#define GOB_SCRIPT_H

#include "common/str.h"
#include "common/stack.h"

#include "gob/totfile.h"

namespace Gob {

class GobEngine;
class Expression;

class Script {
public:
    Script(GobEngine *vm);
    ~Script();

    uint32 read(byte *data, int32 size);
    uint32 peek(byte *data, int32 size, int32 offset = 0) const;

    // Stream properties
    int32 pos() const;
    int32 getSize() const;

    // Stream seeking
    bool seek(int32 offset, int whence = SEEK_SET);
    bool skip(int32 offset);
    bool skipBlock();

    // Reading data
    byte   readByte  ();
    char   readChar  ();
    uint8  readUint8 ();
    uint16 readUint16();
    uint32 readUint32();
    int8   readInt8  ();
    int16  readInt16 ();
    int32  readInt32 ();
    char  *readString(int32 length = -1);

    // Peeking data
    byte   peekByte  (int32 offset = 0);
    char   peekChar  (int32 offset = 0);
    uint8  peekUint8 (int32 offset = 0);
    uint16 peekUint16(int32 offset = 0);
    uint32 peekUint32(int32 offset = 0);
    int8   peekInt8  (int32 offset = 0);
    int16  peekInt16 (int32 offset = 0);
    int32  peekInt32 (int32 offset = 0);
    char  *peekString(int32 offset = 0);

    // Expression parsing functions
    uint16 readVarIndex(uint16 *size = 0, uint16 *type = 0);
    int16 readValExpr(byte stopToken = 99);
    int16 readExpr(byte stopToken, byte *type);
    void  skipExpr(char stopToken);

    // Higher-level expression parsing functions
    char  evalExpr(int16 *pRes);
    bool  evalBool();
    int32 evalInt();

    const char *evalString();

    // Accessing the result of expressions
    int32 getResultInt() const;
    char *getResultStr() const;

    int32 getOffset(byte *ptr) const;
    byte *getData(int32 offset) const;

    byte *getData();

    bool load(const Common::String &fileName);
    void unload();
    bool isLoaded() const;

    void setFinished(bool finished);
    bool isFinished() const;

    // Call stack operations
    void push();
    void pop(bool ret = true);
    void call(uint32 offset);

    void writeByte(int32 offset, byte v);

    // Fixed properties
    uint8  getVersionMajor   () const;
    uint8  getVersionMinor   () const;
    uint32 getVariablesCount () const;
    uint32 getTextsOffset    () const;
    uint32 getResourcesOffset() const;
    uint16 getAnimDataSize   () const;
    uint8  getImFileNumber   () const;
    uint8  getExFileNumber   () const;
    uint8  getCommunHandling () const;

    uint16 getFunctionOffset (uint8 function) const;

    static uint32 getVariablesCount(const char *fileName, GobEngine *vm);

private:
    struct CallEntry {
        byte *totPtr;
        bool finished;
    };

    GobEngine *_vm;
    Expression *_expression;

    bool _finished;

    Common::String _totFile;
    byte *_totData;
    byte *_totPtr;
    uint32 _totSize;

    Common::SeekableReadStream *_lom;

    TOTFile::Properties _totProperties;

    Common::Stack<CallEntry> _callStack;

    bool loadTOT(const Common::String &fileName);
    bool loadLOM(const Common::String &fileName);

    void unloadTOT();
};

} // End of namespace Gob

#endif // GOB_SCRIPT_H