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engines/cge2/fileio.h

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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/>.
+ *
+ */
+
+/*
+ * This code is based on original Sfinx source code
+ * Copyright (c) 1994-1997 Janusz B. Wisniewski and L.K. Avalon
+ */
+
+#ifndef CGE2_FILEIO_H
+#define CGE2_FILEIO_H
+
+#include "common/file.h"
+
+namespace CGE2 {
+
+#define kBtSize       2048
+#define kBtKeySize    13
+#define kBtLevel      2
+#define kBtInnerCount ((kBtSize - 4 /*sizeof(Header) */) / (kBtKeySize + 2 /*sizeof(Inner) */))
+#define kBtLeafCount  ((kBtSize - 4 /*sizeof(Header) */) / (kBtKeySize + 4 + 4 /*sizeof(BtKeypack) */))
+#define kBtValNone    0xFFFF
+#define kBtValRoot    0
+#define kCatName      "VOL.CAT"
+#define kDatName      "VOL.DAT"
+#define kCryptSeed    0xA5
+
+enum ID {
+	kIdNear, kIdMTake, kIdFTake, kIdPhase, kIdSeq,
+	kIdName, kIdType, kIdFront, kIdEast,
+	kIdPortable, kIdTransparent,
+	kIdNone = -1
+};
+
+struct BtKeypack {
+	char _key[kBtKeySize];
+	uint32 _pos;
+	uint32 _size;
+};
+
+struct Inner {
+	uint8  _key[kBtKeySize];
+	uint16 _down;
+};
+
+struct Header {
+	uint16 _count;
+	uint16 _down;
+};
+
+struct BtPage {
+	Header _header;
+	union {
+		// dummy filler to make proper size of union
+		uint8 _data[kBtSize - 4]; /* 4 is the size of struct Header */
+		// inner version of data: key + word-sized page link
+		Inner _inner[kBtInnerCount];
+		// leaf version of data: key + all user data
+		BtKeypack _leaf[kBtLeafCount];
+	};
+
+	void readBTree(Common::ReadStream &s);
+};
+
+class ResourceManager {
+private:
+	struct {
+		BtPage *_page;
+		uint16 _pageNo;
+		int _index;
+	} _buff[kBtLevel];
+
+	BtPage *getPage(int level, uint16 pageId);
+	uint16 catRead(byte *buf, uint16 length);
+	Common::File *_catFile;
+	Common::File *_datFile;
+	void xCrypt(byte *buf, uint16 length);
+public:
+	ResourceManager();
+	~ResourceManager();
+	uint16 read(byte *buf, uint16 length);
+	bool seek(int32 offs, int whence = SEEK_SET);
+
+	BtKeypack *find(const char *key);
+	bool exist(const char *name);
+};
+
+class EncryptedStream {
+private:
+	Common::SeekableReadStream *_readStream;
+	int _lineCount;
+	bool _error;
+public:
+	EncryptedStream(ResourceManager *resman, const char *name);
+	~EncryptedStream();
+	bool err();
+	bool eos();
+	bool seek(int32 offset);
+	int32 pos();
+	int32 size();
+	uint32 read(byte *dataPtr, uint32 dataSize);
+	int16 readSint16LE();
+	uint32 readUint32LE();
+	Common::String readLine();
+	int getLineCount() { return _lineCount; }
+
+	static const char *const kIdTab[];
+};
+
+} // End of namespace CGE2
+
+#endif // CGE2_FILEIO_H