Files
2026-02-02 04:50:13 +01:00

133 lines
3.1 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 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/>.
*
*/
#include "common/memstream.h"
#include "ultima/ultima8/misc/debugger.h"
#include "ultima/ultima8/filesys/flex_file.h"
namespace Ultima {
namespace Ultima8 {
static const int FLEX_TABLE_OFFSET = 0x80;
static const int FLEX_HDR_SIZE = 0x52;
static const char FLEX_HDR_PAD = 0x1A;
FlexFile::FlexFile(Common::SeekableReadStream *rs) : _rs(rs) {
_valid = isFlexFile(_rs);
if (_valid)
_valid = readMetadata();
}
FlexFile::~FlexFile() {
delete _rs;
}
//static
bool FlexFile::isFlexFile(Common::SeekableReadStream *rs) {
rs->seek(0);
int i;
char buf[FLEX_HDR_SIZE];
rs->read(buf, FLEX_HDR_SIZE);
for (i = 0; i < FLEX_HDR_SIZE; ++i) {
if (buf[i] == FLEX_HDR_PAD) break;
}
if (i < FLEX_HDR_SIZE) {
for (++i; i < FLEX_HDR_SIZE; ++i) {
if (buf[i] != FLEX_HDR_PAD) return false;
}
return true;
}
return false;
}
bool FlexFile::readMetadata() {
_rs->seek(FLEX_HDR_SIZE + 2);
uint32 count = _rs->readUint32LE();
if (count > 4095) {
// In practice the largest flex in either Crusader or U8 games has
// 3074 entries, so this seems invalid.
warning("Flex invalid: improbable number of entries %d", count);
return false;
}
if (_rs->size() < FLEX_TABLE_OFFSET + 8 * count) {
warning("Flex invalid: stream not long enough for offset table");
return false;
}
_entries.reserve(count);
_rs->seek(FLEX_TABLE_OFFSET);
for (unsigned int i = 0; i < count; ++i) {
FileEntry fe;
fe._offset = _rs->readUint32LE();
fe._size = _rs->readUint32LE();
_entries.push_back(fe);
}
return true;
}
Common::SeekableReadStream *FlexFile::getDataSource(uint32 index, bool is_text) {
uint32 size;
uint8 *buf = getObject(index, &size);
if (!buf)
return nullptr;
return new Common::MemoryReadStream(buf, size, DisposeAfterUse::YES);
}
uint8 *FlexFile::getObject(uint32 index, uint32 *sizep) {
if (index >= _entries.size())
return nullptr;
uint32 size = _entries[index]._size;
if (size == 0)
return nullptr;
uint8 *object = new uint8[size];
uint32 offset = _entries[index]._offset;
_rs->seek(offset);
_rs->read(object, size);
if (sizep)
*sizep = size;
return object;
}
uint32 FlexFile::getSize(uint32 index) const {
if (index >= _entries.size())
return 0;
return _entries[index]._size;
}
} // End of namespace Ultima8
} // End of namespace Ultima