XEEN: Implement Music playEffect method

engines/xeen/music.cpp

@@ -27,10 +27,15 @@
 
 namespace Xeen {
 
-#define ADLIB_CHANNEL_COUNT 9
 #define CALLBACKS_PER_SECOND 60
 
-Music::Music(Audio::Mixer *mixer) : _mixer(mixer), _effectsData(nullptr) {
+Music::Music(Audio::Mixer *mixer) : _mixer(mixer), _effectsData(nullptr),
+		_musicPtr1(nullptr), _musicPtr2(nullptr), _lowMusicIgnored(false),
+		_fieldF(false), _field109(0), _field10B(0), _field114(0), 
+		_field115(0), _field117(0) {
+	_channels.resize(ADLIB_CHANNEL_COUNT);
+	Common::fill(&_field10D[0], &_field10D[7], 0);
+
 	_mixer = mixer;
 	_opl = OPL::Config::create();
 	_opl->init();
@@ -72,6 +77,10 @@ void Music::onTimer() {
 	flush();
 }
 
+void Music::write(int reg, int val) {
+	_queue.push(RegisterValue(reg, val));
+}
+
 void Music::flush() {
 	Common::StackLock slock(_driverMutex);
 
@@ -85,4 +94,49 @@ void Music::update() {
 	// TODO
 }
 
+void Music::playEffect(uint effectId) {
+	if (!_lowMusicIgnored || effectId < 7 || effectId >= 11) {
+		if (effectId < _effectsOffsets.size()) {
+			_musicPtr1 = _musicPtr2 = &_effectsData[_effectsOffsets[effectId]];
+			_field117 = 0;
+			_field115 = 0;
+			_field114 = 0;
+			reset();
+			_lowMusicIgnored = true;
+		}
+	}
+}
+
+void Music::reset() {
+	if (!_fieldF) {
+		_field109 = 0;
+		setFrequency(7, 0);
+		_channels[7]._outputLevel = 63;
+		setOutputLevel(7, 63);
+	}
+
+	_field10B = 0;
+	setFrequency(8, 0);
+	_channels[8]._outputLevel = 63;
+	setOutputLevel(8, 63);
+}
+
+void Music::setFrequency(byte operatorNum, uint frequency) {
+	write(0xA0 + operatorNum, frequency & 0xff);
+	write(0xB0 + operatorNum, (frequency >> 8));
+}
+
+void Music::setOutputLevel(byte channelNum, uint level) {
+	write(0x40 + OPERATOR2_INDEXES[channelNum], level |
+		(_channels[channelNum]._scalingValue & 0xC0));
+}
+
+const byte Music::OPERATOR1_INDEXES[ADLIB_CHANNEL_COUNT] = {
+	0, 1, 2, 8, 9, 0xA, 0x10, 0x11, 0x12
+};
+
+const byte Music::OPERATOR2_INDEXES[ADLIB_CHANNEL_COUNT] = {
+	3, 4, 5, 0xB, 0xC, 0xD, 0x13, 0x14, 0x15
+};
+
 } // End of namespace Xeen

engines/xeen/music.h

@@ -29,6 +29,8 @@
 #include "common/mutex.h"
 #include "common/queue.h"
 
+#define ADLIB_CHANNEL_COUNT 9
+
 namespace OPL {
 	class OPL;
 }
@@ -45,18 +47,43 @@ struct RegisterValue {
 };
 
 class Music {
+	struct Channel {
+		byte _outputLevel;
+		byte _scalingValue;
+
+		Channel() : _outputLevel(0), _scalingValue(0) {}
+	};
+private:
+	static const byte OPERATOR1_INDEXES[ADLIB_CHANNEL_COUNT];
+	static const byte OPERATOR2_INDEXES[ADLIB_CHANNEL_COUNT];
 private:
 	OPL::OPL *_opl;
 	Common::Mutex _driverMutex;
+	Common::Array<Channel> _channels;
 	Common::Queue<RegisterValue> _queue;
 	const byte *_effectsData;
 	Common::Array<uint16> _effectsOffsets;
+	const byte *_musicPtr1, *_musicPtr2;
+	bool _fieldF;
+	int _field109;
+	int _field10B;
+	byte _field10D[7];
+	int _field114;
+	int _field115;
+	int _field117;
+	bool _lowMusicIgnored;
 private:
 	/**
 	 * Loads effects data that was embedded in the music driver
 	 */
 	void loadEffectsData();
 
+	/**
+	 * Adds a register write to the pending queue that will be flushed
+	 * out to the OPL on the next timer call
+	 */
+	void write(int reg, int val);
+
 	/**
 	 * Timer function for OPL
 	 */
@@ -71,11 +98,31 @@ class Music {
 	 * Updates any playing music
 	 */
 	void update();
+
+	/**
+	 * Does a reset
+	 */
+	void reset();
+
+	/**
+	 * Sets the frequency for an operator
+	 */
+	void setFrequency(byte operatorNum, uint frequency);
+
+	/**
+	 * Sets the output level for a channel
+	 */
+	void setOutputLevel(byte channelNum, uint level);
 protected:
 	Audio::Mixer *_mixer;
 public:
 	Music(Audio::Mixer *mixer);
 	~Music();
+
+	/**
+	 * Starts an effect playing
+	 */
+	void playEffect(uint effectId);
 };
 
 } // End of namespace Xeen