From 1c7f0c0e4a1f1b6c8fe3840ee429347db80f5c59 Mon Sep 17 00:00:00 2001
From: Brian Heim <brianlheim@gmail.com>
Date: Wed, 18 Dec 2019 22:32:14 -0600
Subject: [PATCH] Update examples, add vco.scd

---
 examples/gain.scd    |  5 +++--
 examples/rainbow.scd |  4 ++--
 examples/vco.scd     | 37 +++++++++++++++++++++++++++++++++++++
 3 files changed, 42 insertions(+), 4 deletions(-)
 create mode 100644 examples/vco.scd

diff --git a/examples/gain.scd b/examples/gain.scd
index 322aa7f..ff69f76 100644
--- a/examples/gain.scd
+++ b/examples/gain.scd
@@ -1,10 +1,11 @@
 // Simplest possible script using all variables, demonstrating buffering
-// by Brian Heim
+// by Andrew Belt
+// adapted for SC by Brian Heim
 
 ~vcv_frameDivider = 1;
 ~vcv_bufferSize = 32;
 
-~vcv_process = {|block|
+~vcv_process = { |block|
 	// Loop through each row
 	VcvPrototypeProcessBlock.numRows.do { |i|
 		// Get gain knob
diff --git a/examples/rainbow.scd b/examples/rainbow.scd
index 5f676e4..ebbfc82 100644
--- a/examples/rainbow.scd
+++ b/examples/rainbow.scd
@@ -1,6 +1,6 @@
 // Rainbow RGB LED example
-// by Brian Heim
-// adapted from example by Andrew Belt
+// by Andrew Belt
+// adapted for SC by Brian Heim
 
 // Call process() every 256 audio samples
 ~vcv_frameDivider = 256;
diff --git a/examples/vco.scd b/examples/vco.scd
new file mode 100644
index 0000000..219c27a
--- /dev/null
+++ b/examples/vco.scd
@@ -0,0 +1,37 @@
+// Voltage-controlled oscillator example
+// by Andrew Belt
+// adapted for SC by Brian Heim
+
+~vcv_frameDivider = 1;
+~vcv_bufferSize = 32;
+
+~phase = 0;
+~vcv_process = { |block|
+
+	var pitch, freq, deltaPhase;
+
+	// Knob ranges from -5 to 5 octaves
+	pitch = block.knobs[0] * 10 - 5;
+	// Input follows 1V/oct standard
+	// Take the first input's first buffer value
+	pitch = pitch + block.inputs[0][0];
+
+	// The relationship between 1V/oct pitch and frequency is `freq = 2^pitch`.
+	// Default frequency is middle C (C4) in Hz.
+	// https://vcvrack.com/manual/VoltageStandards.html#pitch-and-frequencies
+	freq = 261.6256 * pow(2, pitch);
+	postf("Freq: % Hz", freq);
+
+	deltaPhase = ~vcv_frameDivider * block.sampleTime * freq;
+
+	// Set all samples in output buffer
+	block.bufferSize.do { |i|
+		// Accumulate phase & wrap around range [0, 1]
+		~phase = (~phase + deltaPhase) % 1.0;
+
+		// Convert phase to sine output
+		block.outputs[0][i] = sin(2pi * ~phase) * 5;
+	};
+
+	block
+}