CGE2: Add file I/O.

5 files changed, 380 insertions, 1 deletions

diff --git a/engines/cge2/cge2.cpp b/engines/cge2/cge2.cpp
index 0b06cd0fb4..8f84f5e31a 100644
--- a/engines/cge2/cge2.cpp
+++ b/engines/cge2/cge2.cpp
@@ -31,11 +31,16 @@ namespace CGE2 {
 
 CGE2Engine::CGE2Engine(OSystem *syst, const ADGameDescription *gameDescription)
 	: Engine(syst), _gameDescription(gameDescription) {
+	_resman = nullptr;
 }
 
 CGE2Engine::~CGE2Engine() {
 }
 
+void CGE2Engine::init() {
+	_resman = new ResourceManager();
+}
+
 bool CGE2Engine::hasFeature(EngineFeature f) const {
 	return false;
 }
@@ -58,6 +63,7 @@ Common::Error CGE2Engine::saveGameState(int slot, const Common::String &desc) {
 }
 
 Common::Error CGE2Engine::run() {
+	init();
 	warning("STUB: CGE2Engine::run()");
 	return Common::kNoError;
 }
diff --git a/engines/cge2/cge2.h b/engines/cge2/cge2.h
index ee4ecf62b1..068b371ff6 100644
--- a/engines/cge2/cge2.h
+++ b/engines/cge2/cge2.h
@@ -30,6 +30,7 @@
 
 #include "engines/engine.h"
 #include "engines/advancedDetector.h"
+#include "cge2/fileio.h"
 
 namespace CGE2 {
 
@@ -45,6 +46,10 @@ public:
 	virtual Common::Error run();
 
 	const ADGameDescription *_gameDescription;
+
+	ResourceManager *_resman;
+private:
+	void init();
 };
 
 } // End of namespace CGE2
diff --git a/engines/cge2/fileio.cpp b/engines/cge2/fileio.cpp
new file mode 100644
index 0000000000..4da2c52cfa
--- /dev/null
+++ b/engines/cge2/fileio.cpp
@@ -0,0 +1,247 @@
+/* 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.
+ *
+ */
+
+/*
+ * This code is based on original Sfinx source code
+ * Copyright (c) 1994-1997 Janus B. Wisniewski and L.K. Avalon
+ */
+
+#include "common/system.h"
+#include "common/str.h"
+#include "common/debug.h"
+#include "common/debug-channels.h"
+#include "common/memstream.h"
+#include "cge2/cge2.h"
+#include "cge2/fileio.h"
+
+namespace CGE2 {
+
+/*-----------------------------------------------------------------------
+ * BtPage
+ *-----------------------------------------------------------------------*/
+void BtPage::readBTree(Common::ReadStream &s) {
+	_header._count = s.readUint16LE();
+	_header._down = s.readUint16LE();
+
+	if (_header._down == kBtValNone) {
+		// Leaf list
+		for (int i = 0; i < kBtLeafCount; ++i) {
+			s.read(_leaf[i]._key, kBtKeySize);
+			_leaf[i]._pos = s.readUint32LE();
+			_leaf[i]._size = s.readUint32LE();
+		}
+	} else {
+		// Root index
+		for (int i = 0; i < kBtInnerCount; ++i) {
+			s.read(_inner[i]._key, kBtKeySize);
+			_inner[i]._down = s.readUint16LE();
+		}
+	}
+}
+
+/*-----------------------------------------------------------------------
+ * ResourceManager
+ *-----------------------------------------------------------------------*/
+ResourceManager::ResourceManager() {
+	_datFile = new Common::File();
+	_datFile->open(kDatName);
+
+	_catFile = new Common::File();
+	_catFile->open(kCatName);
+
+	if (!_datFile->isOpen() || !_catFile->isOpen())
+		error("Unable to open data files");
+
+	for (int i = 0; i < kBtLevel; i++) {
+		_buff[i]._page = new BtPage;
+		_buff[i]._pageNo = kBtValNone;
+		_buff[i]._index = -1;
+		assert(_buff[i]._page != NULL);
+	}
+}
+
+ResourceManager::~ResourceManager() {
+	_datFile->close();
+	delete _datFile;
+
+	_catFile->close();
+	delete _catFile;
+
+	for (int i = 0; i < kBtLevel; i++)
+		delete _buff[i]._page;
+}
+
+void ResourceManager::XCrypt(byte *buf, uint16 length) {
+	byte *b = buf;
+
+	for (uint16 i = 0; i < length; i++)
+		*b++ ^= kCryptSeed;
+}
+
+bool ResourceManager::seek(int32 offs, int whence) {
+	return _datFile->seek(offs, whence);
+}
+
+uint16 ResourceManager::read(byte *buf, uint16 length) {
+	if (!_datFile->isOpen())
+		return 0;
+
+	uint16 bytesRead = _datFile->read(buf, length);
+	if (!bytesRead)
+		error("Read %s - %d bytes", _datFile->getName(), length);
+	XCrypt(buf, length);
+	return bytesRead;
+}
+
+BtPage *ResourceManager::getPage(int level, uint16 pageId) {
+	if (_buff[level]._pageNo != pageId) {
+		int32 pos = pageId * kBtSize;
+		_buff[level]._pageNo = pageId;
+		assert(_catFile->size() > pos);
+		// In the original, there was a check verifying if the
+		// purpose was to write a new file. This should only be
+		// to create a new file, thus it was removed.
+		_catFile->seek(pageId * kBtSize, SEEK_SET);
+
+		// Read in the page
+		byte buffer[kBtSize];
+		int bytesRead = catRead(buffer, kBtSize);
+
+		// Unpack it into the page structure
+		Common::MemoryReadStream stream(buffer, bytesRead, DisposeAfterUse::NO);
+		_buff[level]._page->readBTree(stream);
+		_buff[level]._index = -1;
+	}
+	return _buff[level]._page;
+}
+
+BtKeypack *ResourceManager::find(const char *key) {
+	int lev = 0;
+	uint16 nxt = kBtValRoot;
+	while (!_catFile->eos()) {
+		BtPage *pg = getPage(lev, nxt);
+		// search
+		if (pg->_header._down != kBtValNone) {
+			int i;
+			for (i = 0; i < pg->_header._count; i++) {
+				// Does this work, or does it have to compare the entire buffer?
+				if (scumm_strnicmp((const char *)key, (const char*)pg->_inner[i]._key, kBtKeySize) < 0)
+					break;
+			}
+			nxt = (i) ? pg->_inner[i - 1]._down : pg->_header._down;
+			_buff[lev]._index = i - 1;
+			lev++;
+		} else {
+			int i;
+			for (i = 0; i < pg->_header._count - 1; i++) {
+				if (scumm_stricmp((const char *)key, (const char *)pg->_leaf[i]._key) <= 0)
+					break;
+			}
+			_buff[lev]._index = i;
+			return &pg->_leaf[i];
+		}
+	}
+	return NULL;
+}
+
+bool ResourceManager::exist(const char *name) {
+	return scumm_stricmp(find(name)->_key, name) == 0;
+}
+
+uint16 ResourceManager::catRead(byte *buf, uint16 length) {
+	if (!_catFile->isOpen())
+		return 0;
+
+	uint16 bytesRead = _catFile->read(buf, length);
+	if (!bytesRead)
+		error("Read %s - %d bytes", _catFile->getName(), length);
+	XCrypt(buf, length);
+	return bytesRead;
+}
+
+/*-----------------------------------------------------------------------
+ * EncryptedStream
+ *-----------------------------------------------------------------------*/
+EncryptedStream::EncryptedStream(CGE2Engine *vm, const char *name) : _vm(vm) {
+	_error = false;
+	BtKeypack *kp = _vm->_resman->find(name);
+	if (scumm_stricmp(kp->_key, name) != 0)
+		_error = true;
+
+	_vm->_resman->seek(kp->_pos);
+	byte *dataBuffer;
+	int bufSize;
+
+	if ((strlen(name) > 4) && (scumm_stricmp(name + strlen(name) - 4, ".SPR") == 0)) {
+		// SPR files have some inconsistencies. Some have extra 0x1A at the end, some others
+		// do not have a carriage return at the end of the last line
+		// Therefore, we remove this ending 0x1A and add extra new lines.
+		// This fixes bug #3537527
+		dataBuffer = (byte *)malloc(kp->_size + 2);
+		_vm->_resman->read(dataBuffer, kp->_size);
+		if (dataBuffer[kp->_size - 1] == 0x1A)
+			dataBuffer[kp->_size - 1] = '\n';
+		dataBuffer[kp->_size] = '\n';
+		dataBuffer[kp->_size + 1] = '\n';
+		bufSize = kp->_size + 2;
+	} else {
+		dataBuffer = (byte *)malloc(kp->_size);
+		_vm->_resman->read(dataBuffer, kp->_size);
+		bufSize = kp->_size;
+	}
+
+	_readStream = new Common::MemoryReadStream(dataBuffer, bufSize, DisposeAfterUse::YES);
+}
+
+uint32 EncryptedStream::read(byte *dataPtr, uint32 dataSize) {
+	return _readStream->read(dataPtr, dataSize);
+}
+
+bool EncryptedStream::err() {
+	return (_error & _readStream->err());
+}
+
+bool EncryptedStream::eos() {
+	return _readStream->eos();
+}
+
+bool EncryptedStream::seek(int32 offset) {
+	return _readStream->seek(offset);
+}
+
+Common::String EncryptedStream::readLine() {
+	return _readStream->readLine();
+}
+
+int32 EncryptedStream::size() {
+	return _readStream->size();
+}
+
+int32 EncryptedStream::pos() {
+	return _readStream->pos();
+}
+
+EncryptedStream::~EncryptedStream() {
+	delete _readStream;
+}
+
+} // End of namespace CGE2
diff --git a/engines/cge2/fileio.h b/engines/cge2/fileio.h
new file mode 100644
index 0000000000..42bb2ee352
--- /dev/null
+++ b/engines/cge2/fileio.h
@@ -0,0 +1,120 @@
+/* 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.
+ *
+ */
+
+/*
+ * This code is based on original Sfinx source code
+ * Copyright (c) 1994-1997 Janus B. Wisniewski and L.K. Avalon
+ */
+
+#ifndef CGE2_FILEIO_H
+#define CGE2_FILEIO_H
+
+#include "common/file.h"
+
+namespace CGE2 {
+
+class CGE2Engine;
+
+#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
+
+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:
+	CGE2Engine *_vm;
+	Common::SeekableReadStream *_readStream;
+	bool _error;
+public:
+	EncryptedStream(CGE2Engine *vm, const char *name);
+	~EncryptedStream();
+	bool err();
+	bool eos();
+	bool seek(int32 offset);
+	int32 pos();
+	int32 size();
+	uint32 read(byte *dataPtr, uint32 dataSize);
+	Common::String readLine();
+};
+
+} // End of namespace CGE2
+
+#endif // CGE2_FILEIO_H
diff --git a/engines/cge2/module.mk b/engines/cge2/module.mk
index 75f2743286..fc710b663a 100644
--- a/engines/cge2/module.mk
+++ b/engines/cge2/module.mk
@@ -2,7 +2,8 @@ MODULE := engines/cge2
 
 MODULE_OBJS = \
 	cge2.o \
-	detection.o
+	detection.o \
+	fileio.o
 
 # This module can be built as a plugin
 ifeq ($(ENABLE_CGE2), DYNAMIC_PLUGIN)