From a911e82a7f6ee85053f2573c1900daf7049b86e8 Mon Sep 17 00:00:00 2001
From: Brian Heim <brianlheim@gmail.com>
Date: Wed, 18 Dec 2019 19:17:55 -0600
Subject: [PATCH] Add SC rainbow example

---
 examples/rainbow.scd | 42 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 42 insertions(+)
 create mode 100644 examples/rainbow.scd

diff --git a/examples/rainbow.scd b/examples/rainbow.scd
new file mode 100644
index 0000000..5f676e4
--- /dev/null
+++ b/examples/rainbow.scd
@@ -0,0 +1,42 @@
+// Rainbow RGB LED example
+// by Brian Heim
+// adapted from example by Andrew Belt
+
+// Call process() every 256 audio samples
+~vcv_frameDivider = 256;
+~vcv_bufferSize = 1;
+
+// From https://en.wikipedia.org/wiki/HSL_and_HSV#HSV_to_RGB
+~hsvToRgb = { |h, s, v|
+	var c, x, rgb, m;
+	h = h * 6;
+	c = v * s;
+	x = c * (1 - abs(h % 2 - 1));
+	rgb = case
+		{ h < 1 } { [c, x, 0] }
+		{ h < 2 } { [x, c, 0] }
+		{ h < 3 } { [0, c, x] }
+		{ h < 4 } { [0, x, c] }
+		{ h < 5 } { [x, 0, c] }
+		{ [c, 0, x] };
+
+	rgb + (v - c);
+};
+
+~phase = 0;
+~vcv_process = { |block|
+	~phase = ~phase + block.sampleTime * ~vcv_frameDivider * 0.5;
+	~phase = ~phase % 1.0;
+
+	VcvPrototypeProcessBlock.numRows.do { |i|
+		var h = (1 - i / 6 + ~phase) % 1;
+		var rgb = ~hsvToRgb.value(h, 1, 1);
+		3.do { |c|
+			block.lights[i][c] = rgb[c];
+			block.switchLights[i][c] = rgb[c];
+		};
+		block.outputs[i][0] = sin(2pi * h) * 5 + 5;
+	};
+
+	block
+}