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/* 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 COMMON_DATA_IO_H
#define COMMON_DATA_IO_H
#include "common/scummsys.h"
namespace Common {
enum class EndianStorageFormat {
Big,
Little,
};
// Traits for a storage format. You can specialize this to make more storage formats
// that have their own behavior.
template<class TDataFormat>
struct DataFormatTraits {
};
template<>
struct DataFormatTraits<EndianStorageFormat> {
static inline bool isLittleEndian(EndianStorageFormat storageFormat) {
return storageFormat == EndianStorageFormat::Little;
}
};
template<class TDataFormat, class T>
struct SimpleDataIO {
static const uint kMaxSize = sizeof(T);
static uint computeSize(TDataFormat dataFormat);
static void encode(TDataFormat dataFormat, byte *data, const T &value);
static void decode(TDataFormat dataFormat, const byte *data, T &value);
};
template<class TDataFormat, class T>
uint SimpleDataIO<TDataFormat, T>::computeSize(TDataFormat dataFormat) {
return sizeof(T);
}
template<class TDataFormat, class T>
void SimpleDataIO<TDataFormat, T>::encode(TDataFormat dataFormat, byte *data, const T &value) {
const byte *valueBytes = reinterpret_cast<const byte *>(&value);
byte *dataBytes = reinterpret_cast<byte *>(data);
const bool isTargetLE = DataFormatTraits<TDataFormat>::isLittleEndian(dataFormat);
#ifdef SCUMM_LITTLE_ENDIAN
const bool isSystemLE = true;
#endif
#ifdef SCUMM_BIG_ENDIAN
const bool isSystemLE = false;
#endif
const bool requiresSwap = (isSystemLE != isTargetLE);
byte temp[sizeof(T)];
if (requiresSwap) {
for (uint i = 0; i < sizeof(T); i++)
temp[i] = valueBytes[sizeof(T) - 1 - i];
} else {
for (uint i = 0; i < sizeof(T); i++)
temp[i] = valueBytes[i];
}
for (uint i = 0; i < sizeof(T); i++)
dataBytes[i] = temp[i];
}
template<class TDataFormat, class T>
void SimpleDataIO<TDataFormat, T>::decode(TDataFormat dataFormat, const byte *data, T &value) {
byte *valueBytes = reinterpret_cast<byte *>(&value);
const byte *dataBytes = reinterpret_cast<const byte *>(data);
const bool isTargetLE = DataFormatTraits<TDataFormat>::isLittleEndian(dataFormat);
#ifdef SCUMM_LITTLE_ENDIAN
const bool isSystemLE = true;
#endif
#ifdef SCUMM_BIG_ENDIAN
const bool isSystemLE = false;
#endif
const bool requiresSwap = (isSystemLE != isTargetLE);
byte temp[sizeof(T)];
if (requiresSwap) {
for (uint i = 0; i < sizeof(T); i++)
temp[i] = dataBytes[sizeof(T) - 1 - i];
} else {
for (uint i = 0; i < sizeof(T); i++)
temp[i] = dataBytes[i];
}
for (uint i = 0; i < sizeof(T); i++)
valueBytes[i] = temp[i];
}
template<class TDataFormat, class T>
struct DataIO {
};
template<class TDataFormat>
struct DataIO<TDataFormat, uint8> : public SimpleDataIO<TDataFormat, uint8> {
};
template<class TDataFormat>
struct DataIO<TDataFormat, uint16> : public SimpleDataIO<TDataFormat, uint16> {
};
template<class TDataFormat>
struct DataIO<TDataFormat, uint32> : public SimpleDataIO<TDataFormat, uint32> {
};
template<class TDataFormat>
struct DataIO<TDataFormat, uint64> : public SimpleDataIO<TDataFormat, uint64> {
};
template<class TDataFormat>
struct DataIO<TDataFormat, int8> : public SimpleDataIO<TDataFormat, int8> {
};
template<class TDataFormat>
struct DataIO<TDataFormat, int16> : public SimpleDataIO<TDataFormat, int16> {
};
template<class TDataFormat>
struct DataIO<TDataFormat, int32> : public SimpleDataIO<TDataFormat, int32> {
};
template<class TDataFormat>
struct DataIO<TDataFormat, int64> : public SimpleDataIO<TDataFormat, int64> {
};
template<class TDataFormat>
struct DataIO<TDataFormat, char> : public SimpleDataIO<TDataFormat, char> {
};
template<class TDataFormat>
struct DataIO<TDataFormat, float> : public SimpleDataIO<TDataFormat, float> {
};
template<class TDataFormat>
struct DataIO<TDataFormat, double> : public SimpleDataIO<TDataFormat, double> {
};
template<class TDataFormat, class T, class... TMore>
struct DataMultipleIO;
template<class TDataFormat, class T>
struct DataMultipleIO<TDataFormat, T> {
static const uint kMaxSize = DataIO<TDataFormat, T>::kMaxSize;
static uint computeSize(TDataFormat dataFormat);
static void encode(TDataFormat dataFormat, byte *data, const T &value);
static void decode(TDataFormat dataFormat, const byte *data, T &value);
};
template<class TDataFormat, class T>
uint DataMultipleIO<TDataFormat, T>::computeSize(TDataFormat dataFormat) {
return DataIO<TDataFormat, T>::computeSize(dataFormat);
}
template<class TDataFormat, class T>
void DataMultipleIO<TDataFormat, T>::encode(TDataFormat dataFormat, byte *data, const T &value) {
return DataIO<TDataFormat, T>::encode(dataFormat, data, value);
}
template<class TDataFormat, class T>
void DataMultipleIO<TDataFormat, T>::decode(TDataFormat dataFormat, const byte *data, T &value) {
return DataIO<TDataFormat, T>::decode(dataFormat, data, value);
}
template<class TDataFormat, class T, uint TSize>
struct DataMultipleIO<TDataFormat, T[TSize]> {
static const uint kMaxSize = DataIO<TDataFormat, T>::kMaxSize * TSize;
static uint computeSize(TDataFormat dataFormat);
static void encode(TDataFormat dataFormat, byte *data, const T (&value)[TSize]);
static void decode(TDataFormat dataFormat, const byte *data, T (&value)[TSize]);
};
template<class TDataFormat, class T, uint TSize>
uint DataMultipleIO<TDataFormat, T[TSize]>::computeSize(TDataFormat dataFormat) {
return DataMultipleIO<TDataFormat, T>::computeSize(dataFormat) * TSize;
}
template<class TDataFormat, class T, uint TSize>
void DataMultipleIO<TDataFormat, T[TSize]>::encode(TDataFormat dataFormat, byte *data, const T (&value)[TSize]) {
const uint elementSize = DataIO<TDataFormat, T>::computeSize(dataFormat);
for (uint i = 0; i < TSize; i++)
DataMultipleIO<TDataFormat, T>::encode(dataFormat, data + elementSize * i, value[i]);
}
template<class TDataFormat, class T, uint TSize>
void DataMultipleIO<TDataFormat, T[TSize]>::decode(TDataFormat dataFormat, const byte *data, T (&value)[TSize]) {
const uint elementSize = DataIO<TDataFormat, T>::computeSize(dataFormat);
for (uint i = 0; i < TSize; i++)
DataMultipleIO<TDataFormat, T>::decode(dataFormat, data + elementSize * i, value[i]);
}
template<class TDataFormat, class T, class... TMore>
struct DataMultipleIO {
static const uint kMaxSize = DataIO<TDataFormat, T>::kMaxSize + DataMultipleIO<TDataFormat, TMore...>::kMaxSize;
static uint computeSize(TDataFormat dataFormat);
static void encode(TDataFormat dataFormat, byte *data, const T &firstValue, const TMore &...moreValues);
static void decode(TDataFormat dataFormat, const byte *data, T &firstValue, TMore &...moreValues);
};
template<class TDataFormat, class T, class... TMore>
uint DataMultipleIO<TDataFormat, T, TMore...>::computeSize(TDataFormat dataFormat) {
return DataMultipleIO<TDataFormat, T>::computeSize(dataFormat) + DataMultipleIO<TDataFormat, TMore...>::computeSize(dataFormat);
}
template<class TDataFormat, class T, class... TMore>
void DataMultipleIO<TDataFormat, T, TMore...>::encode(TDataFormat dataFormat, byte *data, const T &firstValue, const TMore &...moreValues) {
DataMultipleIO<TDataFormat, T>::encode(dataFormat, data, firstValue);
DataMultipleIO<TDataFormat, TMore...>::encode(dataFormat, data + DataMultipleIO<TDataFormat, T>::computeSize(dataFormat), moreValues...);
}
template<class TDataFormat, class T, class... TMore>
void DataMultipleIO<TDataFormat, T, TMore...>::decode(TDataFormat dataFormat, const byte *data, T &firstValue, TMore &...moreValues) {
DataMultipleIO<TDataFormat, T>::decode(dataFormat, data, firstValue);
DataMultipleIO<TDataFormat, TMore...>::decode(dataFormat, data + DataMultipleIO<TDataFormat, T>::computeSize(dataFormat), moreValues...);
}
} // End of namespace Common
#endif
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