add virtual copy ctor for RageSoundReaders

stepmania/src/RageSoundReader.h

@@ -16,6 +16,7 @@ public:
 	virtual int SetPosition_Fast(int ms) { return SetPosition_Accurate(ms); }
 	virtual int Read(char *buf, unsigned len) = 0;
 	virtual ~SoundReader() { }
+	virtual SoundReader *Copy() const = 0;
 
 	bool Error() const { return !error.empty(); }
 	string GetError() const { return error; }

stepmania/src/RageSoundReader_SDL_Sound.cpp

@@ -6,7 +6,7 @@
  * something wrong with my SDL_sound MAD wrapper ...
  */
 
-#ifdef _DEBUG
+#ifdef DEBUG
 #pragma comment(lib, "SDL_sound-1.0.0/lib/sdl_sound_static_d.lib")
 #else
 #pragma comment(lib, "SDL_sound-1.0.0/lib/sdl_sound_static.lib")
@@ -21,8 +21,9 @@ const int samplerate = 44100;
 /* The amount of data to read from SDL_sound at once. */
 const int read_block_size = 1024;
 
-bool SoundReader_SDL_Sound::Open(CString filename)
+bool SoundReader_SDL_Sound::Open(CString filename_)
 {
+	filename=filename_;
 	static bool initialized = false;
 	if(!initialized)
 	{
@@ -150,3 +151,11 @@ SoundReader_SDL_Sound::~SoundReader_SDL_Sound()
 {
 	Sound_FreeSample(Sample);
 }
+
+SoundReader *SoundReader_SDL_Sound::Copy() const
+{
+	SoundReader_SDL_Sound *ret = new SoundReader_SDL_Sound;
+	ret->Open(filename);
+	return ret;
+}
+

stepmania/src/RageSoundReader_SDL_Sound.h

@@ -9,6 +9,7 @@ class SoundReader_SDL_Sound: public SoundReader {
 	const char *inbuf;
 	unsigned avail;
 	int SetPosition(int ms, bool accurate);
+	CString filename;
 
 public:
 	bool Open(CString filename);
@@ -18,6 +19,7 @@ public:
 	int SetPosition_Fast(int ms) { return SetPosition(ms, false); }
 	int Read(char *buf, unsigned len);
 	~SoundReader_SDL_Sound();
+	SoundReader *Copy() const;
 };
 
 #endif