Removed XOR encoding stuff from File class; instead the new Scumm::XORFile class provides this functionality now

svn-id: r13597

7 files changed, 42 insertions, 38 deletions

diff --git a/common/file.cpp b/common/file.cpp
index 4bb6e94fad..24c8907002 100644
--- a/common/file.cpp
+++ b/common/file.cpp
@@ -132,7 +132,6 @@ void File::setDefaultDirectory(const Common::String &directory) {
 File::File() {
 	_handle = NULL;
 	_ioFailed = false;
-	_encbyte = 0;
 	_name = 0;
 }
 
@@ -141,7 +140,7 @@ File::~File() {
 	delete [] _name;
 }
 
-bool File::open(const char *filename, const char *directory, AccessMode mode, byte encbyte) {
+bool File::open(const char *filename, const char *directory, AccessMode mode) {
 	if (_handle) {
 		debug(2, "File %s already opened", filename);
 		return false;
@@ -174,8 +173,6 @@ bool File::open(const char *filename, const char *directory, AccessMode mode, by
 		return false;
 	}
 
-	_encbyte = encbyte;
-
 	int len = strlen(filename);
 	if (_name != 0)
 		delete [] _name;
@@ -263,19 +260,10 @@ uint32 File::read(void *ptr, uint32 len) {
 		_ioFailed = true;
 	}
 
-	if (_encbyte != 0) {
-		uint32 t_size = real_len;
-		while (t_size--) {
-			*ptr2++ ^= _encbyte;
-		}
-	}
-
 	return real_len;
 }
 
 uint32 File::write(const void *ptr, uint32 len) {
-	byte *tmp = 0;
-	
 	if (_handle == NULL) {
 		error("File is not open!");
 		return 0;
@@ -284,25 +272,10 @@ uint32 File::write(const void *ptr, uint32 len) {
 	if (len == 0)
 		return 0;
 
-	if (_encbyte != 0) {
-		// Maybe FIXME: while it's efficient to do the encoding here,
-		// it not really nice for a write function to modify its input.
-		// Maybe we should work on a copy here...
-		tmp = (byte *)malloc(len);
-		for (uint32 i = 0; i < len; i ++) {
-			tmp[i] = ((const byte *)ptr)[i] ^ _encbyte;
-		}
-		ptr = tmp;
-	}
-
 	if ((uint32)fwrite(ptr, 1, len, _handle) != len) {
 		clearerr(_handle);
 		_ioFailed = true;
 	}
 
-	if (_encbyte != 0) {
-		free(tmp);
-	}
-
 	return len;
 }
diff --git a/common/file.h b/common/file.h
index 42d521495f..ba8eb469e4 100644
--- a/common/file.h
+++ b/common/file.h
@@ -32,7 +32,6 @@ private:
 
 	FILE * _handle;
 	bool _ioFailed;
-	byte _encbyte;
 	char *_name;	// For debugging
 
 	static FILE *fopenNoCase(const char *filename, const char *directory, const char *mode);
@@ -50,7 +49,7 @@ public:
 	File();
 	virtual ~File();
 	bool open(const char *filename, const Common::String &directory) { return open(filename, directory.c_str()); }
-	bool open(const char *filename, const char *directory = NULL, AccessMode mode = kFileReadMode, byte encbyte = 0);
+	bool open(const char *filename, const char *directory = NULL, AccessMode mode = kFileReadMode);
 	void close();
 	bool isOpen() const;
 	bool ioFailed() const;
@@ -62,8 +61,6 @@ public:
 	void seek(int32 offs, int whence = SEEK_SET);
 	uint32 read(void *ptr, uint32 size);
 	uint32 write(const void *ptr, uint32 size);
-
-	void setEnc(byte value) { _encbyte = value; }
 };
 
 #endif
diff --git a/common/stream.h b/common/stream.h
index bd20bdbc20..e5fdd96b09 100644
--- a/common/stream.h
+++ b/common/stream.h
@@ -80,16 +80,21 @@ public:
  * XORReadStream is a wrapper around an arbitrary other ReadStream,
  * which 'decrypts' the data being read by XORing all data bytes with the given
  * encryption 'key'.
+ *
+ * Currently, this is not used anywhere, it's just a demo of how one can chain
+ * streams if necessary.
  */
 class XORReadStream : public ReadStream {
 private:
 	byte _encbyte;
 	ReadStream *_realStream;
 public:
-	XORReadStream(ReadStream *in, byte enc = 0) : _realStream(in), _encbyte(enc) {}
+	XORReadStream(ReadStream *in = 0, byte enc = 0) : _realStream(in), _encbyte(enc) {}
+	void setStream(ReadStream *in) { _realStream = in; }
 	void setEnc(byte value) { _encbyte = value; }
 
 	uint32 read(void *ptr, uint32 size) {
+		assert(_realStream);
 		uint32 len = _realStream->read(ptr, size);
 		if (_encbyte) {
 			byte *p = (byte *)ptr;
@@ -101,6 +106,13 @@ public:
 	}
 };
 
+/**
+ * Simple memory based 'stream', which implements the ReadStream interface for
+ * a plain memory block.
+ *
+ * Currently not used anywhere, just a proof of concept, and meant to give an
+ * idea of what streams can be used for.
+ */
 class MemoryReadStream : public ReadStream {
 private:
 	const byte *_ptr;
diff --git a/scumm/resource.cpp b/scumm/resource.cpp
index 9fe9eacc81..4dbd1ff6af 100644
--- a/scumm/resource.cpp
+++ b/scumm/resource.cpp
@@ -222,7 +222,8 @@ bool ScummEngine::openResourceFile(const char *filename, byte encByte) {
 		_fileHandle.close();
 	}
 
-	_fileHandle.open(filename, getGameDataPath(), File::kFileReadMode, encByte);
+	_fileHandle.open(filename);
+	_fileHandle.setEnc(encByte);
 
 	return _fileHandle.isOpen();
 }
@@ -888,6 +889,7 @@ static const uint16 num_steps_table[] = {
 	240, 276, 340, 460,
 	600, 860, 1200, 1600
 };
+
 int ScummEngine::convert_extraflags(byte * ptr, byte * src_ptr) {
 	int flags = src_ptr[0];
 
diff --git a/scumm/script_v5.cpp b/scumm/script_v5.cpp
index 3d50febab3..4f0e9bcd8e 100644
--- a/scumm/script_v5.cpp
+++ b/scumm/script_v5.cpp
@@ -2684,7 +2684,7 @@ void ScummEngine_v5::decodeParseString() {
 			break;
 		case 15:	// SO_TEXTSTRING
 			msg = _scriptPointer;
-			_scriptPointer += resStrLen(_scriptPointer)+ 1;
+			_scriptPointer += resStrLen(_scriptPointer) + 1;
 
 			switch (textSlot) {
 			case 0:
diff --git a/scumm/scumm.h b/scumm/scumm.h
index e7971cb586..62570d1d74 100644
--- a/scumm/scumm.h
+++ b/scumm/scumm.h
@@ -60,6 +60,25 @@ struct ScummGameSettings;
 
 typedef Common::Map<Common::String, int> ObjectIDMap;
 
+class XORFile : public File {
+private:
+	byte _encbyte;
+public:
+	XORFile() : _encbyte(0) {}
+	void setEnc(byte value) { _encbyte = value; }
+
+	uint32 read(void *ptr, uint32 len) {
+		uint32 realLen = File::read(ptr, len);
+		if (_encbyte) {
+			byte *p = (byte *)ptr;
+			byte *end = p + realLen;
+			while (p < end)
+				*p++ ^= _encbyte;
+		}
+		return realLen;
+	}
+};
+
 // Use g_scumm from error() ONLY
 extern ScummEngine *g_scumm;
 
@@ -599,7 +618,7 @@ protected:
 	void doSentence(int c, int b, int a);
 
 	/* Should be in Resource class */
-	File _fileHandle;
+	XORFile _fileHandle;
 	uint32 _fileOffset;
 	int _resourceHeaderSize;
 	Common::String _gameName;	// This is the name we use for opening resource files
diff --git a/scumm/sound.cpp b/scumm/sound.cpp
index 8d40f16c64..a668c8c82a 100644
--- a/scumm/sound.cpp
+++ b/scumm/sound.cpp
@@ -892,7 +892,7 @@ void Sound::startSfxSound(File *file, int file_size, PlayingSoundHandle *handle,
 
 File *Sound::openSfxFile() {
 	char buf[256];
-	File *file = new File();
+	XORFile *file = new XORFile();
 	_offsetTable = NULL;
 	
 	struct SoundFileExtensions {
@@ -935,7 +935,8 @@ File *Sound::openSfxFile() {
 
 	if (!file->isOpen()) {
 		sprintf(buf, "%s.tlk", _vm->getGameName());
-		file->open(buf, _vm->getGameDataPath(), File::kFileReadMode, 0x69);
+		file->open(buf);
+		file->setEnc(0x69);
 		_soundMode = kVOCMode;
 	} else if (_soundMode != kVOCMode) {
 		/* Now load the 'offset' index in memory to be able to find the MP3 data