Random: Make external input polyphonic.

src/Random.cpp

@@ -44,8 +44,8 @@ struct Random : Module {
 		NUM_LIGHTS
 	};
 
-	float lastVoltage = 0.f;
-	float nextVoltage = 0.f;
+	float lastVoltage[16] = {};
+	float nextVoltage[16] = {};
 	/** Waits at 1 until reset */
 	float phase = 0.f;
 	float clockFreq = 0.f;
@@ -54,7 +54,7 @@ struct Random : Module {
 	/** External clock timer */
 	dsp::Timer clockTimer;
 	dsp::SchmittTrigger clockTrigger;
-	dsp::PulseGenerator trigGenerator;
+	dsp::PulseGenerator pulseGenerator;
 
 	Random() {
 		config(NUM_PARAMS, NUM_INPUTS, NUM_OUTPUTS, NUM_LIGHTS);
@@ -91,11 +91,9 @@ struct Random : Module {
 	}
 
 	void process(const ProcessArgs& args) override {
-		// Params
-		float shape = params[SHAPE_PARAM].getValue();
-		shape += inputs[SHAPE_INPUT].getVoltage() / 10.f * params[SHAPE_CV_PARAM].getValue();
-		shape = clamp(shape, 0.f, 1.f);
+		int channels = std::max(1, inputs[EXTERNAL_INPUT].getChannels());
 
+		// Params
 		float rand = 0.f;
 		if (!inputs[EXTERNAL_INPUT].isConnected()) {
 			rand = params[RAND_PARAM].getValue();
@@ -117,21 +115,23 @@ struct Random : Module {
 				return;
 
 			// Generate next random voltage
-			lastVoltage = nextVoltage;
+			// lastVoltage = nextVoltage;
+			std::copy_n(nextVoltage, channels, lastVoltage);
+
 			if (inputs[EXTERNAL_INPUT].isConnected()) {
-				nextVoltage = inputs[EXTERNAL_INPUT].getVoltage();
+				inputs[EXTERNAL_INPUT].readVoltages(nextVoltage);
 			}
 			else {
 				// Crossfade new random voltage with last
 				float v = 10.f * random::uniform();
 				if (!uni)
 					v -= 5.f;
-				nextVoltage = crossfade(nextVoltage, v, rand);
+				nextVoltage[0] = crossfade(nextVoltage[0], v, rand);
 			}
 
 			phase = 0.f;
 
-			trigGenerator.trigger(1e-3f);
+			pulseGenerator.trigger(1e-3f);
 			lights[PROB_LIGHT].setBrightness(3.f);
 		};
 
@@ -167,12 +167,24 @@ struct Random : Module {
 		phase += deltaPhase;
 		phase = std::min(1.f, phase);
 
+		// Shape param
+		float shape = params[SHAPE_PARAM].getValue();
+		shape += inputs[SHAPE_INPUT].getVoltage() / 10.f * params[SHAPE_CV_PARAM].getValue();
+		shape = clamp(shape, 0.f, 1.f);
+
+		auto interpolateOutput = [&](Output& output, float v) {
+			for (int c = 0; c < channels; c++) {
+				float vc = rescale(v, 0.f, 1.f, lastVoltage[c], nextVoltage[c]);
+				output.setVoltage(vc, c);
+			}
+			output.setChannels(channels);
+		};
+
 		// Stepped
 		if (outputs[STEPPED_OUTPUT].isConnected()) {
 			float steps = std::ceil(std::pow(shape, 2) * 15 + 1);
 			float v = std::ceil(phase * steps) / steps;
-			v = rescale(v, 0.f, 1.f, lastVoltage, nextVoltage);
-			outputs[STEPPED_OUTPUT].setVoltage(v);
+			interpolateOutput(outputs[STEPPED_OUTPUT], v);
 		}
 
 		// Linear
@@ -185,8 +197,7 @@ struct Random : Module {
 			else {
 				v = 1.f;
 			}
-			v = rescale(v, 0.f, 1.f, lastVoltage, nextVoltage);
-			outputs[LINEAR_OUTPUT].setVoltage(v);
+			interpolateOutput(outputs[LINEAR_OUTPUT], v);
 		}
 
 		// Smooth
@@ -200,8 +211,7 @@ struct Random : Module {
 			else {
 				v = -1.f;
 			}
-			v = rescale(v, 1.f, -1.f, lastVoltage, nextVoltage);
-			outputs[SMOOTH_OUTPUT].setVoltage(v);
+			interpolateOutput(outputs[SMOOTH_OUTPUT], v);
 		}
 
 		// Exp
@@ -217,12 +227,12 @@ struct Random : Module {
 			else {
 				v = 1.f;
 			}
-			v = rescale(v, 0.f, 1.f, lastVoltage, nextVoltage);
-			outputs[EXPONENTIAL_OUTPUT].setVoltage(v);
+			interpolateOutput(outputs[EXPONENTIAL_OUTPUT], v);
 		}
 
 		// Trigger output
-		outputs[TRIG_OUTPUT].setVoltage(trigGenerator.process(args.sampleTime) ? 10.f : 0.f);
+		bool pulse = pulseGenerator.process(args.sampleTime);
+		outputs[TRIG_OUTPUT].setVoltage(pulse ? 10.f : 0.f);
 
 		// Lights
 		lights[RATE_LIGHT].setSmoothBrightness(0.f, args.sampleTime);