[Performous-commit] Vincent Le Ligeour : Added note synth to audio code

[Lasse Kärkkäi. <tr...@us...>]

Module: performous
Branch: master
Commit: 7b5d9e1559f236a44c38e8c82675f1d627423d94

Author: Vincent Le Ligeour <yo...@us...>
Date:   Mon Jul  5 21:26:46 2010 +0200

Added note synth to audio code

---

 game/audio.cc |   45 +++++++++++++++++++++++++++++++++++++++++++++
 game/audio.hh |    2 +-
 2 files changed, 46 insertions(+), 1 deletions(-)

diff --git a/game/audio.cc b/game/audio.cc
index ac93f15..1cb771a 100644
--- a/game/audio.cc
+++ b/game/audio.cc
@@ -102,6 +102,36 @@ struct Sample {
 	}
 };
 
+struct Synth {
+  private:
+	Notes m_notes;
+	double srate; ///< Sample rate
+  public:
+	Synth(Notes const& notes, unsigned int sr) : m_notes(notes), srate(sr) {};
+	void operator()(float* begin, float* end, double position) {
+		static double phase = 0.0;
+		for (float *i = begin; i < end; ++i) *i *= 0.3; // Decrease music volume
+
+		std::vector<float> mixbuf(end - begin);
+		Notes::const_iterator it = m_notes.begin();
+
+		while (it != m_notes.end() && it->end < position) ++it;
+		if (it == m_notes.end() || it->type == Note::SLEEP || it->begin > position) { phase = 0.0; return; }
+		int note = it->note % 12;
+		double d = (note + 1) / 13.0;
+		double freq = MusicalScale().getNoteFreq(note + 12);
+		double value = 0.0;
+		// Synthesize tones
+		for (size_t i = 0, iend = mixbuf.size(); i != iend; ++i) {
+			if (i % 2 == 0) {
+				value = d * 0.2 * std::sin(phase) + 0.2 * std::sin(2 * phase) + (1.0 - d) * 0.2 * std::sin(4 * phase);
+				phase += 2.0 * M_PI * freq / srate;
+			}
+			begin[i] += value;
+		}
+	}
+};
+
 
 struct Command {
 	enum { TRACK_FADE, SAMPLE_RESET } type;
@@ -112,6 +142,8 @@ struct Command {
 struct Output {
 	boost::mutex mutex;
 	boost::mutex samples_mutex;
+	boost::mutex synth_mutex;
+	std::auto_ptr<Synth> synth;
 	std::auto_ptr<Music> preloading;
 	boost::ptr_vector<Music> playing, disposing;
 	boost::ptr_map<std::string, Sample> samples;
@@ -167,6 +199,13 @@ struct Output {
 				}
 			}
 		}
+		// Mix synth if available (should be done at the end)
+		{
+			boost::mutex::scoped_try_lock l(synth_mutex, boost::defer_lock);
+			if(l.try_lock() && synth.get() && !playing.empty()) {
+				(*synth.get())(begin, end, playing[0].pos());
+			}
+		}
 	}
 };
 
@@ -326,5 +365,11 @@ void Audio::streamFade(std::string track, double fadeLevel) {
 	o.commands.push_back(cmd);
 }
 
+void Audio::toggleSynth(Notes const& notes) {
+	Output& o = self->output;
+	boost::mutex::scoped_lock l(o.synth_mutex);
+	o.synth.get() ?  o.synth.reset() : o.synth.reset(new Synth(notes, getSR()));
+}
+
 boost::ptr_vector<Analyzer>& Audio::analyzers() { return self->analyzers; }
 
diff --git a/game/audio.hh b/game/audio.hh
index 1087c8f..dab6770 100644
--- a/game/audio.hh
+++ b/game/audio.hh
@@ -54,7 +54,7 @@ public:
 	void togglePause() { pause(!isPaused()); }
 	void pause(bool state = true);
 	bool isPaused() const;
-	void toggleSynth(Notes const&) { /*m_notes = (m_notes ? NULL : &notes); */} ///< toggles synth playback
+	void toggleSynth(Notes const&); ///< toggles synth playback
 	/// Adjust volume level of a single track (used for muting incorrectly played instruments). Range 0.0 to 1.0.
 	void streamFade(std::string track, double volume);
 	double getSR() const { return 48000.0; }