From e01c7106f63df6f63595eddf9fe7cacefd510017 Mon Sep 17 00:00:00 2001
From: Toon Claes <toon@iotcl.com>
Date: Fri, 30 Mar 2018 15:44:18 +0200
Subject: [PATCH] Add Rainbow stalker effect

There already exist 2 rainbow LED effects, this adds a third, using
the LED-Stalker effect.

When you press a key, the LED on that key will cycle through all the
colors of the rainbow, independent of the colors of other keys.
---
 README.md                        |  4 ++++
 src/Kaleidoscope/LED-Stalker.cpp | 13 +++++++++++++
 src/Kaleidoscope/LED-Stalker.h   |  7 +++++++
 3 files changed, 24 insertions(+)

diff --git a/README.md b/README.md
index dece8113..debffaa6 100644
--- a/README.md
+++ b/README.md
@@ -76,6 +76,10 @@ The plugin provides the following effects:
 
 > A blazing trail of fire will follow our fingers!
 
+### `Rainbow()`
+
+> Leave a rainbow behind, where your fingers has been!
+
 ## Dependencies
 
 * [Kaleidoscope-LEDControl](https://github.com/keyboardio/Kaleidoscope-LEDControl)
diff --git a/src/Kaleidoscope/LED-Stalker.cpp b/src/Kaleidoscope/LED-Stalker.cpp
index 42c043d4..050fd28c 100644
--- a/src/Kaleidoscope/LED-Stalker.cpp
+++ b/src/Kaleidoscope/LED-Stalker.cpp
@@ -127,6 +127,19 @@ cRGB BlazingTrail::compute(uint8_t *step) {
   return color;
 }
 
+// Rainbow
+Rainbow::Rainbow(void) {
+}
+
+cRGB Rainbow::compute(uint8_t *step) {
+  if (*step > 0)
+    *step -= 1;
+  else
+    *step = 0;
+
+  return hsvToRgb(255 - *step, 255, *step);
+}
+
 }
 
 }
diff --git a/src/Kaleidoscope/LED-Stalker.h b/src/Kaleidoscope/LED-Stalker.h
index 99caed29..6cf9b464 100644
--- a/src/Kaleidoscope/LED-Stalker.h
+++ b/src/Kaleidoscope/LED-Stalker.h
@@ -67,6 +67,13 @@ class BlazingTrail : public StalkerEffect::ColorComputer {
   cRGB compute(uint8_t *step) final;
 };
 
+class Rainbow : public StalkerEffect::ColorComputer {
+ public:
+  Rainbow(void);
+
+  cRGB compute(uint8_t *step) final;
+};
+
 }
 }