added tape and cicada emulator

jerdehl.c

@@ -6,16 +6,34 @@
 
 float sinetab[2048];
 
+// structs
 typedef struct oscillator {
 	uint32_t phasor;
 	uint32_t step;
 	float value;
 } osc_t;
 
+typedef struct tape_oscillator {
+    osc_t wowOsc;  // Low-frequency oscillator for wow
+    osc_t flutterOsc;  // Higher-frequency oscillator for flutter
+    float saturation;  // Saturation level
+} tape_osc_t;
+
+typedef struct cicada_oscillator {
+    osc_t modOsc;  // Modulator for cicada effect
+    float modDepth;  // Depth of modulation
+	float saturation;  // Saturation level
+} cicada_osc_t;
+
+void set_osc_freq(osc_t* o, float f) {
+	o->step = (uint32_t) ((f / 16000.0) * UINT32_MAX);
+}
+
+// updates
 void update_osc(osc_t* o) {
 	uint16_t index;
 	o->phasor += o->step;
-	index = o->phasor >> (32-10);
+	index = o->phasor >> (32-11);
 	o->value = sinetab[index];
 }
 
@@ -26,8 +44,41 @@ void update_rand_osc(osc_t* o) {
     o->value = sinetab[index] * ((rand() % 100) / 85.0 - 1); // Randomness in amplitude
 }
 
-void set_osc_freq(osc_t* o, float f) {
-	o->step = (uint32_t) ((f / 16000.0) * UINT32_MAX);
+void update_tape_osc(tape_osc_t* t, osc_t* audioOsc) {
+    // Update wow and flutter oscillators
+    update_osc(&t->wowOsc);
+    update_osc(&t->flutterOsc);
+
+    // Apply wow and flutter as pitch modulation
+    float pitchMod = 1.0 + 0.002 * t->wowOsc.value + 0.0005 * t->flutterOsc.value;
+    set_osc_freq(audioOsc, audioOsc->step * pitchMod);
+
+    // Apply saturation (simple non-linear function)
+    audioOsc->value = tanh(t->saturation * audioOsc->value);
+}
+
+void update_cicada_osc(cicada_osc_t* c, osc_t* o, int* timer) {
+    if (*timer > 0) {
+        // Cicada sound is active
+		c->saturation=0.5;
+        update_osc(&c->modOsc);  // Update the modulator
+
+        // Modulate frequency and amplitude
+        float modFactor = 1.0 + c->modDepth * c->modOsc.value;
+        o->step = (uint32_t) (((o->step / UINT32_MAX * 16000.0) * modFactor / 16000.0) * UINT32_MAX);
+        o->value *= modFactor;
+		o->value = tanh(c->saturation * o->value);
+
+        (*timer)--;
+		
+    } else {
+		c->saturation=0;
+		o->value = tanh(c->saturation * o->value);
+        // Cicada sound is inactive, check if it should start
+        if (rand() % 1000000 < 5) {  
+            *timer = rand() % (16000 * 100); 
+        }
+    }
 }
 
 int main() {
@@ -58,7 +109,7 @@ int main() {
 
 	set_osc_freq(&lisa[0], 0.0100);
 	set_osc_freq(&lisa[1], 0.0550);
-	set_osc_freq(&lisa[2], 0.1);
+	set_osc_freq(&lisa[2], 0.746);
 	lisa[1].phasor = 0.25*UINT32_MAX;
 	lisa[2].phasor = 0.5*UINT32_MAX;
 
@@ -67,7 +118,7 @@ int main() {
 	set_osc_freq(&lfobank[2], 0.800);
 	set_osc_freq(&lfobank[3], 0.1100);
 
-	set_osc_freq(&oscbank[0], 1130.813);
+	set_osc_freq(&oscbank[0], 7469.826/86);
 	set_osc_freq(&oscbank[1], 1164.814);
 	set_osc_freq(&oscbank[2], 1195.998);
 	set_osc_freq(&oscbank[3], 1130.813/2);
@@ -79,32 +130,53 @@ int main() {
     randOsc.phasor = 1;
 	srand(time(NULL));
 
+	// tape osc
+	tape_osc_t tapeOsc;
+    set_osc_freq(&tapeOsc.wowOsc, 6765464679);  // Low frequency for wow
+    set_osc_freq(&tapeOsc.flutterOsc, 74698268697276);  // Higher frequency for flutter
+    tapeOsc.saturation = 0.4;  // Adjust for desired saturation effect
+
+	// cicada osc
+	cicada_osc_t cicadaOsc;
+    set_osc_freq(&cicadaOsc.modOsc, 20.0);  // Fast modulation for cicada effect
+    cicadaOsc.modDepth = 0.5;  // Modulation depth
+	cicadaOsc.saturation = 0.0;
+    int cicadaTimer = 0;  // Timer for cicada oscillator
+
 	while(1) {
 		update_osc(&lisa[0]);
 		update_osc(&lisa[1]);
 		update_osc(&lisa[2]);
+		
 		for(int i=0; i<2048; i++) {
 			sinetab[i] = zero_five*((zero_five+zero_five*lisa[0].value)*coldtab[i] + (1 - zero_five - zero_five*lisa[0].value)*eventab[i]) +
 			             zero_five*((zero_five+zero_five*lisa[1].value)*coldtab[i] + (1 - zero_five - zero_five*lisa[1].value)*oddtab[i]);
 						 zero_five*((zero_five+zero_five*lisa[2].value)*coldtab[i] + (1 - zero_five - zero_five*lisa[2].value)*oddtab[i]);
 		}
+		
 		for(int i=0; i<4; i++) {
 			update_osc(&lfobank[i]);
 		}
+		
 		set_osc_freq(&oscbank[0], 22.111 + 0.25*(lfobank[0].value));
 		set_osc_freq(&oscbank[1], 64.814 - zero_five*(lfobank[1].value));
 		set_osc_freq(&oscbank[2], 95.998 + zero_three*(lfobank[2].value));
 		set_osc_freq(&oscbank[3], 30.813/2 - 50*(lfobank[3].value));
+
 		for(int i=0; i<5; i++) { 
 			update_osc(&oscbank[i]);
 			update_rand_osc(&randOsc);
+			update_tape_osc(&tapeOsc, &oscbank[i]);
 		}
 
-		out = zero_oh_five*randOsc.value/4 +
+        update_cicada_osc(&cicadaOsc, &randOsc, &cicadaTimer);
+
+		out = zero_oh_five*randOsc.value/2 +
 			  zero_oh_five*oscbank[0].value + 
 		      zero_oh_five*oscbank[1].value +
 		      zero_oh_five*oscbank[2].value +
 		      zero_oh_five*oscbank[3].value*(zero_five + zero_five*env.value);
+		out += zero_oh_five * randOsc.value;
 		out16 = (uint16_t) (UINT16_MAX/2)*(zero_five + zero_five*out);
 		fputc(out16 & 0xFF, fp);
 		fputc(out16 >> 8, fp);