Add index as ColorMapper parameter

Add rainbow FastLED example

README.md

@@ -103,6 +103,9 @@ fully implemented, feel free to open an issue, so I know where to focus on first
 
 ## Recent Breaking Changes
 
+ - ########################################
+   The color mapper for `NoteRangeFastLED` and the like now takes a second 
+   parameter that represents the index of the LED within the LED strip.
  - 3c01c7d5eb60e59720540d5a77095468e6984a58  
    The **maximum supported ADC resolution is now used by default** (e.g. 13 bits
    on Teensy 3.x, 12 bits on ESP32).  

examples/2. MIDI Input/1. LEDs/10.Note-FastLED-ColorMapper/10.Note-FastLED-ColorMapper.ino

@@ -0,0 +1,68 @@
+/**
+ * This example demonstrates the use of addressable LEDs that respond to 
+ * incoming  MIDI note events. This example uses a custom color mapper to
+ * get a rainbow effect across the LED strip.
+ * 
+ * @boards  AVR, AVR USB, Teensy 3.x, ESP32
+ * 
+ * @note    You might lose incoming MIDI data while the LED strip is being 
+ *          updated. To avoid this, don't use an Arduino UNO.  
+ *          See <https://github.com/FastLED/FastLED/wiki/Interrupt-problems>
+ * 
+ * Connections  
+ * -----------
+ * 
+ * - 2: Data pin of NeoPixel LED strip with at least 8 pixels.
+ * 
+ * Behavior
+ * --------
+ * 
+ * If a MIDI Note On event for note 0x3C (C4 or middle C) is sent, the first LED
+ * will light up, if a Note Off event for that note is sent, the LED will turn 
+ * off.  
+ * If a MIDI Note On event for note 0x3D (C#4) is sent, the second LED will 
+ * light up, etc.  
+ * (A Note On event with a velocity of zero also counts as a Note Off event.)
+ * 
+ * Mapping
+ * -------
+ * 
+ * Route the MIDI output of a MIDI keyboard to the Arduino's MIDI input. Then
+ * play a middle C and some notes above it on the keyboard.
+ * 
+ * Written by PieterP, 2019-10-15  
+ * https://github.com/tttapa/Control-Surface
+ */
+#include <FastLED.h>
+// Must be before Control Surface to enable FastLED features of Control Surface
+#include <Control_Surface.h>
+
+// Define the array of leds.
+Array<CRGB, 8> leds = {};
+// The data pin with the strip connected.
+constexpr uint8_t ledpin = 2;
+
+USBMIDI_Interface midi;
+
+// Create a functor that maps the velocity and the index of a note to a color.
+struct RainbowColorMapper {
+  CHSV operator()(uint8_t velocity, uint8_t index) const {
+    return {255 * index / leds.length, 255, 2 * velocity};
+  }
+};
+
+using namespace MIDI_Notes;
+NoteRangeFastLED<leds.length, RainbowColorMapper> midiled = {leds, note(C, 4)};
+
+void setup() {
+  // See FastLED examples and documentation for more information.
+  FastLED.addLeds<NEOPIXEL, ledpin>(leds.data, leds.length);
+  FastLED.setCorrection(TypicalPixelString);
+  midiled.setBrightness(128);
+  Control_Surface.begin();
+}
+
+void loop() {
+  Control_Surface.loop();
+  FastLED.show();
+}

examples/examples.h

@@ -897,6 +897,47 @@
  * https://github.com/tttapa/Control-Surface
  */
 
+/**
+ * @example   "10.Note-FastLED-ColorMapper.ino"
+ * 
+ * 10.Note-FastLED-ColorMapper
+ * ===========================
+ *
+ * This example demonstrates the use of addressable LEDs that respond to 
+ * incoming  MIDI note events. This example uses a custom color mapper to
+ * get a rainbow effect across the LED strip.
+ * 
+ * @boards  AVR, AVR USB, Teensy 3.x, ESP32
+ * 
+ * @note    You might lose incoming MIDI data while the LED strip is being 
+ *          updated. To avoid this, don't use an Arduino UNO.  
+ *          See <https://github.com/FastLED/FastLED/wiki/Interrupt-problems>
+ * 
+ * Connections  
+ * -----------
+ * 
+ * - 2: Data pin of NeoPixel LED strip with at least 8 pixels.
+ * 
+ * Behavior
+ * --------
+ * 
+ * If a MIDI Note On event for note 0x3C (C4 or middle C) is sent, the first LED
+ * will light up, if a Note Off event for that note is sent, the LED will turn 
+ * off.  
+ * If a MIDI Note On event for note 0x3D (C#4) is sent, the second LED will 
+ * light up, etc.  
+ * (A Note On event with a velocity of zero also counts as a Note Off event.)
+ * 
+ * Mapping
+ * -------
+ * 
+ * Route the MIDI output of a MIDI keyboard to the Arduino's MIDI input. Then
+ * play a middle C and some notes above it on the keyboard.
+ * 
+ * Written by PieterP, 2019-10-15  
+ * https://github.com/tttapa/Control-Surface
+ */
+
 /**
  * @example   "1.Note-LED.ino"
  * 

src/MIDI_Inputs/LEDs/FastLED.cpp

@@ -5,7 +5,8 @@
 
 BEGIN_CS_NAMESPACE
 
-Color DefaultColorMapper::operator()(uint8_t value) const {
+Color DefaultColorMapper::operator()(uint8_t value, uint8_t index) const {
+    (void)index;
     uint8_t r = pgm_read_byte_near(NovationLaunchpadColorLUT + 3 * value + 2);
     uint8_t g = pgm_read_byte_near(NovationLaunchpadColorLUT + 3 * value + 1);
     uint8_t b = pgm_read_byte_near(NovationLaunchpadColorLUT + 3 * value + 0);

src/MIDI_Inputs/LEDs/FastLED.hpp

@@ -17,11 +17,11 @@ struct Color {
 #endif
 };
 
-/// The default mapping from a 7-bit MIDI value to an RGB color.  
+/// The default mapping from a 7-bit MIDI value to an RGB color.
 /// This uses the Novation Launchpad mapping.
 struct DefaultColorMapper {
     /// Map from a 7-bit MIDI value to an RGB color.
-    Color operator()(uint8_t value) const;
+    Color operator()(uint8_t value, uint8_t index) const;
 };
 
 END_CS_NAMESPACE
@@ -37,13 +37,13 @@ BEGIN_CS_NAMESPACE
 template <class ColorMapper>
 class NoteCCFastLED {
   public:
-    NoteCCFastLED(CRGB *leds, const ColorMapper &colormapper)
-        : leds(leds), colormapper{colormapper} {}
+    NoteCCFastLED(CRGB *ledcolors, const ColorMapper &colormapper)
+        : ledcolors(ledcolors), colormapper{colormapper} {}
 
     /** 
      * @brief   Set the maximum brightness of the LEDs.
-     * @param  brightness
-     *         The maximum brightness [0, 255]
+     * @param   brightness
+     *          The maximum brightness [0, 255]
      */
     void setBrightness(uint8_t brightness) { this->brightness = brightness; }
     /// Get the maximum brightness of the LEDs.
@@ -57,32 +57,35 @@ class NoteCCFastLED {
     template <class T>
     void update(const T &t, uint8_t index) {
         uint8_t value = t.getValue(index);
-        leds[index] = CRGB{colormapper(value)}.nscale8_video(brightness);
+        ledcolors[index] =
+            CRGB{colormapper(value, index)}.nscale8_video(brightness);
     }
 
     template <class T>
     void update(const T &t) {
         for (uint8_t index = 0; index < t.length(); ++index) {
             uint8_t value = t.getValue(index);
-            leds[index] = CRGB{colormapper(value)}.nscale8_video(brightness);
+            ledcolors[index] =
+                CRGB{colormapper(value, index)}.nscale8_video(brightness);
         }
     }
 
   private:
-    CRGB *leds;
+    CRGB *ledcolors;
     uint8_t brightness = 255;
 
   public:
     ColorMapper colormapper;
 };
 
+/// @addtogroup midi-input-elements-leds
+/// @{
+
 /**
  * @brief   
  * 
  * @tparam  RangeLen 
  * @tparam  DefaultColorMapper 
- * 
- * @ingroup midi-input-elements-leds
  */
 template <uint8_t RangeLen, class ColorMapper = DefaultColorMapper>
 class NoteRangeFastLED
@@ -343,6 +346,8 @@ class CCValueFastLED
 
 } // namespace Bankable
 
+/// @}
+
 END_CS_NAMESPACE
 
 #endif

test/MIDI_Inputs/test-MIDINote.cpp

@@ -45,7 +45,7 @@ TEST(NoteRange, NoteOnNoteOff) {
 
     ChannelMessageMatcher midimsg3 = {0x80, CHANNEL_5, 0x3C, 0x7E};
     MIDIInputElementNote::updateAllWith(midimsg3);
-    
+
     EXPECT_EQ(mn.getValue(0), 0x00);
     EXPECT_EQ(mn.getValue(1), 0x7D);
 }
@@ -336,20 +336,17 @@ TEST(NoteValueLED, NoteOnNoteOff) {
     NoteValueLED mnl = {2, {0x3C, CHANNEL_5}};
     mnl.begin();
 
-    ::testing::Sequence seq;
+    ::testing::InSequence seq;
 
-    EXPECT_CALL(ArduinoMock::getInstance(), pinMode(2, OUTPUT)).InSequence(seq);
-    EXPECT_CALL(ArduinoMock::getInstance(), digitalWrite(2, LOW))
-        .InSequence(seq);
+    EXPECT_CALL(ArduinoMock::getInstance(), pinMode(2, OUTPUT));
+    EXPECT_CALL(ArduinoMock::getInstance(), digitalWrite(2, LOW));
     MIDIInputElementNote::beginAll();
 
-    EXPECT_CALL(ArduinoMock::getInstance(), digitalWrite(2, HIGH))
-        .InSequence(seq);
+    EXPECT_CALL(ArduinoMock::getInstance(), digitalWrite(2, HIGH));
     ChannelMessageMatcher midimsg1 = {0x90, CHANNEL_5, 0x3C, 0x7E};
     MIDIInputElementNote::updateAllWith(midimsg1);
 
-    EXPECT_CALL(ArduinoMock::getInstance(), digitalWrite(2, LOW))
-        .InSequence(seq);
+    EXPECT_CALL(ArduinoMock::getInstance(), digitalWrite(2, LOW));
     ChannelMessageMatcher midimsg2 = {0x80, CHANNEL_5, 0x3C, 0x7E};
     MIDIInputElementNote::updateAllWith(midimsg2);