Added non pitched additive synthesis

src/modules/ProjectorModule.cpp

@@ -191,9 +191,8 @@ ProjectorModule::ProjectorModule(): Module() {
 
 
 	//audio
-	m_nbTracks=50;
-    //m_maxAudioValue = (std::numeric_limits<int>::max())/(m_width * m_height);
-    m_maxAudioValue = (std::numeric_limits<int>::max())/(m_width);
+	m_nbTracks=3000;
+    m_maxAudioValue = (std::numeric_limits<int>::max())/(m_width * m_height);
     m_audioMixSize = AudioManager::getInstance()->getMixSize();
     m_audioBufSize = AudioManager::getInstance()->getBufferSize();
 	m_imgBufSize = m_audioBufSize+3;

src/shaders/render43.fs

@@ -110,6 +110,46 @@ float random (vec3 st){
 out vec4 color;
 
 void additiveSynth(vec4 color) {
+
+	int nbTracks=3000;
+	float note = 20.0 + floor(color.x * float(nbTracks))/float(nbTracks)*80.0;
+	int ind = int(color.x*float(nbTracks));
+	float freq=0.0;
+
+	//count this fragment
+	if(imageAtomicAdd(audioTex, ivec2(0, ind), 1)<1) {
+		//if the audio has not been generated by another fragment
+		//compute frequency
+		freq = float(440.0 * pow(2.0, (note-69.0)/12.0));
+		//retrieve either new or old phase, depending on if audio was processed
+		float phase = float(imageLoad(audioTex, ivec2(1, ind)).x);
+		if(audioNextBuf>0) {//if new phase
+			//retrieve it
+			phase = float(imageLoad(audioTex, ivec2(2, ind)).x);
+			//store it as previous phase
+			imageStore(audioTex, ivec2(1, ind), ivec4(int(phase)));
+		}
+
+		float outputPhase = phase;
+		float samplesPerPeriod = (audioRate/freq);
+		float phaseStep = 1.0;
+		for(int i=0; i<audioBufSize; i++) {
+			//compute and store value starting from 3rd column
+			float s = sin((phase/samplesPerPeriod) * 2.0 * M_PI);
+			imageStore(audioTex, ivec2(i+3, ind), ivec4(int(s*maxAudioValue)));
+
+			//increase phase
+			phase=mod(phase + phaseStep, samplesPerPeriod);
+		}
+
+		//remove audioMixSize steps and write phase to output
+		outputPhase=mod(outputPhase+phaseStep*(audioBufSize-audioMixSize), 
+						samplesPerPeriod);
+		imageStore(audioTex, ivec2(2, ind), ivec4(int(outputPhase)));
+	}
+}
+
+void pitchedAdditiveSynth(vec4 color) {
 	float freq=0.0;
 	float note = 20 + color.x * 80;
 	int ind=0;