Implement premix proc via an AudioStream / Channel (eventually we'll remove the setupPremix method which takes a proc pointer)

svn-id: r15522

sound/audiostream.cpp

@@ -302,42 +302,6 @@ void AppendableMemoryStream<stereo, is16Bit, isUnsigned, isLE>::append(const byt
 	}
 }
 
-#pragma mark -
-#pragma mark --- Procedural stream ---
-#pragma mark -
-
-
-#if 0
-// Work in progress!!! Not yet usable/finished/working/anything :-)
-
-class ProcInputStream : public AudioStream {
-public:
-	typedef void InputProc (void *refCon, int16 *data, uint len);
-
-private:
-	const int _rate;
-	const bool _isStereo;
-	InputProc *_proc;
-	void *_refCon;
-
-public:
-	ProcInputStream(int rate, bool stereo, InputProc *proc, void *refCon)
-		: _rate(rate), _isStereo(stereo), _proc(proc), _refCon(refCon) { }
-	int readBuffer(int16 *buffer, const int numSamples) {
-		(_proc)(_refCon, buffer, numSamples);
-		return numSamples;
-	}
-	int16 read() {
-		int16 sample;
-		(_proc)(_refCon, &sample, 1);
-		return sample;
-	}
-	bool isStereo() const { return _isStereo; }
-	bool endOfData() const { return false; }
-	
-	int getRate() const { return _rate; }
-};
-#endif
 
 #pragma mark -
 #pragma mark --- Input stream factories ---

sound/mixer.cpp

@@ -98,6 +98,43 @@ public:
 	void finish();
 };
 
+
+#pragma mark -
+#pragma mark --- Procedural stream ---
+#pragma mark -
+
+
+class ProcInputStream : public AudioStream {
+public:
+	typedef void (*InputProc)(void *refCon, int16 *data, uint len);
+
+private:
+	const int _rate;
+	const bool _isStereo;
+	InputProc _proc;
+	void *_refCon;
+
+public:
+	ProcInputStream(int rate, bool stereo, InputProc proc, void *refCon)
+		: _rate(rate), _isStereo(stereo), _proc(proc), _refCon(refCon) { }
+	int readBuffer(int16 *buffer, const int numSamples) {
+		memset(buffer, 0, 2 * numSamples);	// FIXME
+		(_proc)(_refCon, buffer, _isStereo ? (numSamples / 2) : numSamples);
+		return numSamples;
+	}
+	int16 read() {
+		error("ProcInputStream::read not supported");
+		int16 sample[2] = { 0, 0 };
+		(_proc)(_refCon, sample, 1);
+		return sample[0];
+	}
+	bool isStereo() const { return _isStereo; }
+	bool endOfData() const { return false; }
+	
+	int getRate() const { return _rate; }
+};
+
+
 #pragma mark -
 #pragma mark --- SoundMixer ---
 #pragma mark -
@@ -107,8 +144,7 @@ SoundMixer::SoundMixer() {
 	_syst = OSystem::instance();
 	_mutex = _syst->createMutex();
 
-	_premixParam = 0;
-	_premixProc = 0;
+	_premixChannel = 0;
 	int i = 0;
 
 	_globalVolume = 0;
@@ -131,6 +167,10 @@ SoundMixer::SoundMixer() {
 SoundMixer::~SoundMixer() {
 	_syst->clearSoundCallback();
 	stopAll();
+
+	delete _premixChannel;
+	_premixChannel = 0;
+
 	_syst->deleteMutex(_mutex);
 }
 
@@ -140,8 +180,31 @@ bool SoundMixer::isPaused() {
 
 void SoundMixer::setupPremix(PremixProc *proc, void *param) {
 	Common::StackLock lock(_mutex);
-	_premixParam = param;
-	_premixProc = proc;
+
+	delete _premixChannel;
+	_premixChannel = 0;
+	
+	if (proc == 0)
+		return;
+
+	// Create an input stream
+	AudioStream *input = new ProcInputStream(_outputRate, true, proc, param);
+
+	// Create the channel
+	_premixChannel = new Channel(this, 0, input, true, false);
+}
+
+void SoundMixer::setupPremix(AudioStream *stream) {
+	Common::StackLock lock(_mutex);
+
+	delete _premixChannel;
+	_premixChannel = 0;
+	
+	if (stream == 0)
+		return;
+
+	// Create the channel
+	_premixChannel = new Channel(this, 0, stream, false, false);
 }
 
 void SoundMixer::newStream(PlayingSoundHandle *handle, uint rate, byte flags, uint32 buffer_size, byte volume, int8 balance) {
@@ -315,8 +378,8 @@ void SoundMixer::mix(int16 *buf, uint len) {
 	memset(buf, 0, 2 * len * sizeof(int16));
 
 	if (!_paused) {
-		if (_premixProc)
-			_premixProc(_premixParam, buf, len);
+		if (_premixChannel)
+			_premixChannel->mix(buf, len);
 
 		// now mix all channels
 		for (int i = 0; i != NUM_CHANNELS; i++)

sound/mixer.h

@@ -66,8 +66,7 @@ private:
 	OSystem *_syst;
 	OSystem::MutexRef _mutex;
 
-	void *_premixParam;
-	PremixProc *_premixProc;
+	Channel *_premixChannel;
 
 	uint _outputRate;
 
@@ -96,13 +95,24 @@ public:
 	 * Set the premix procedure. This is mainly used for the adlib music, but
 	 * is not limited to it. The premix proc is invoked by the mixer whenever
 	 * it needs to generate any data, before any other mixing takes place. The
-	 * premixer than has a chanve to fill the mix buffer with data (usually
+	 * premixer than has a chance to fill the mix buffer with data (usually
 	 * music samples). It should generate the specified number of 16bit stereo
 	 * samples (i.e. len * 4 bytes). The endianness of these samples shall be
 	 * the native endianness.
+	 *
+	 * @obsolete Instead of this, use the other setupPremix method which
+	 *           takes an AudioStream.
 	 */
 	void setupPremix(PremixProc *proc, void *param);
 
+	/**
+	 * Set the premix stream. This is mainly used for the adlib music, but
+	 * is not limited to it. The premix stream is invoked by the mixer whenever
+	 * it needs to generate any data, before any other mixing takes place.
+	 */
+	void setupPremix(AudioStream *stream);
+
+
 	// start playing a raw sound
 	void playRaw(PlayingSoundHandle *handle, void *sound, uint32 size, uint rate, byte flags,
 				int id = -1, byte volume = 255, int8 balance = 0, uint32 loopStart = 0, uint32 loopEnd = 0);