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/>.
 *
 */

#ifndef MADE_SCRIPT_H
#define MADE_SCRIPT_H

#include "common/textconsole.h"

namespace Made {

// Define this to dump all game scripts and a usage statistic of all
// opcodes/extended functions instead of running the actual game.
// Then run ScummVM with debuglevel 1.
//#define DUMP_SCRIPTS

class MadeEngine;
class ScriptFunctions;

const int kScriptStackSize = 1000;
const int kScriptStackLimit = kScriptStackSize + 1;

class ScriptStack {
public:
    ScriptStack() {
        for (int16 i = 0; i < kScriptStackSize; i++)
            _stack[i] = 0;
        _stackPos = kScriptStackSize;
    }
    ~ScriptStack() {}
    inline int16 top() const { return _stack[_stackPos]; }
    inline int16 pop() {
        if (_stackPos == kScriptStackSize)
            error("ScriptStack::pop() Stack underflow");
        return _stack[_stackPos++];
    }
    inline void push(int16 value = 0) {
        if (_stackPos == 0)
            error("ScriptStack::push() Stack overflow");
        _stack[--_stackPos] = value;
    }
    inline void setTop(int16 value) { _stack[_stackPos] = value; }
    inline int16 peek(int16 index) const {
        if (index >= kScriptStackSize)
            error("ScriptStack::peek(%d) Stack underflow", index);
        else if (index < 0)
            error("ScriptStack::peek(%d) Stack overflow", index);
        return _stack[index];
    }
    inline void poke(int16 index, int16 value) {
        if (index >= kScriptStackSize)
            error("ScriptStack::poke(%d) Stack underflow", index);
        else if (index < 0)
            error("ScriptStack::poke(%d) Stack overflow", index);
        _stack[index] = value;
    }
    inline void alloc(int16 count) { _stackPos -= count; }
    inline void free(int16 count) { _stackPos += count; }
    inline int16 getStackPos() const { return _stackPos; }
    inline void setStackPos(int16 stackPtr) {
        if (stackPtr > kScriptStackSize)
            error("ScriptStack::setStackPos(%d) Stack underflow", stackPtr);
        else if (stackPtr < 0)
            error("ScriptStack::setStackPos(%d) Stack overflow", stackPtr);
        _stackPos = stackPtr;
    }
    inline int16 *getStackPtr() { return &_stack[_stackPos]; }
protected:
    int16 _stack[kScriptStackSize];
    int16 _stackPos;
};

class ScriptInterpreter {
public:
    ScriptInterpreter(MadeEngine *vm);
    ~ScriptInterpreter();
    int16 runScript(int16 scriptObjectIndex, int16 argc = 0, int16 *argv = nullptr);
#ifdef DUMP_SCRIPTS
    void dumpScript(int16 objectIndex, int *opcodeStats, int *externStats);
    void dumpObject(int16 objectIndex);
    void dumpAllScripts();
#endif
protected:
    MadeEngine *_vm;

    ScriptStack _stack;
    int16 _entryStackPos, _localStackPos;
    int16 _runningScriptObjectIndex;
    byte *_codeBase, *_codeIp;
    bool _running;

    ScriptFunctions *_functions;

    byte readByte();
    int16 readInt16();

    typedef void (ScriptInterpreter::*CommandProc)();
    struct CommandEntry {
        CommandProc proc;
        const char *desc;
#ifdef DUMP_SCRIPTS
        const char *sig;
#endif
    };

    const CommandEntry *_commands;
    int16 _commandsMax;

    void cmd_branchTrue();
    void cmd_branchFalse();
    void cmd_branch();
    void cmd_true();
    void cmd_false();
    void cmd_push();
    void cmd_not();
    void cmd_add();
    void cmd_sub();
    void cmd_mul();
    void cmd_div();
    void cmd_mod();
    void cmd_band();
    void cmd_bor();
    void cmd_bnot();
    void cmd_lt();
    void cmd_eq();
    void cmd_gt();
    void cmd_loadConstant();
    void cmd_loadVariable();
    void cmd_getObjectProperty();
    void cmd_setObjectProperty();
    void cmd_set();
    void cmd_print();
    void cmd_terpri();
    void cmd_printNumber();
    void cmd_vref();
    void cmd_vset();
    void cmd_vsize();
    void cmd_exit();
    void cmd_return();
    void cmd_call();
    void cmd_svar();
    void cmd_sset();
    void cmd_split();
    void cmd_snlit();
    void cmd_yorn();
    void cmd_save();
    void cmd_restore();
    void cmd_arg();
    void cmd_aset();
    void cmd_tmp();
    void cmd_tset();
    void cmd_tspace();
    void cmd_class();
    void cmd_objectp();
    void cmd_vectorp();
    void cmd_restart();
    void cmd_rand();
    void cmd_randomize();
    void cmd_send();
    void cmd_extend();
    void cmd_catch();
    void cmd_cdone();
    void cmd_throw();
    void cmd_functionp();
    void cmd_le();
    void cmd_ge();
    void cmd_varx();
    void cmd_setx();

};

} // End of namespace Made

#endif /* MADE_H */