scummvm/engines/gob/variables.h
Sven Hesse db13af5337 GOB: Make the variable stack endianness-independent
Since Urban Runner casts int16s to uint32 before pushing them onto the
stack and after popping assumes it's little endian, we have explicitely
preserve the variable space endianness while pushing/popping.

svn-id: r55277
2011-01-17 13:37:14 +00:00

171 lines
4.3 KiB
C++

/* 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 2
* 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, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
* $URL$
* $Id$
*
*/
#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();
protected:
void write8(byte *buf, uint8 data) const;
void write16(byte *buf, uint16 data) const;
void write32(byte *buf, uint32 data) const;
uint8 read8(const byte *buf) const;
uint16 read16(const byte *buf) const;
uint32 read32(const byte *buf) const;
};
class VariablesBE : public Variables {
public:
VariablesBE(uint32 size);
~VariablesBE();
protected:
void write8(byte *buf, uint8 data) const;
void write16(byte *buf, uint16 data) const;
void write32(byte *buf, uint32 data) const;
uint8 read8(const byte *buf) const;
uint16 read16(const byte *buf) const;
uint32 read32(const byte *buf) const;
};
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