implement color palette support for AURA

WTFRGB.ino

@@ -63,6 +63,11 @@ void loadEEPROM(bool forceReset) {
   for (auto& effect : effects) {
     effect->loadFromEEPROM();
   }
+
+  // Call post-init hooks when everything has been loaded.
+  for (auto& effect : effects) {
+    effect->postInit();
+  }
 }
 
 void writeAllToEEPROM() {

aura.cpp

@@ -1,21 +1,28 @@
 #include "aura.h"
+#include "color.h"
 
 // ==== The Aura Rainbow Effect ====
-// TODO: Implement arbitrary color selection
 int auraCounter = 0;
-int auraWidth = NUM_LEDS / 3;
-int auraDecrement;
+int auraWidth;
+unsigned char paletteCounter;
+CRGB curColor, nextColor;
 
 void AuraEffect::reset() {
   auraCounter = 0;
+  paletteCounter = 0;
   auraWidth = NUM_LEDS / 3;
-  auraDecrement = MAX_BRIGHTNESS / auraWidth;
 }
 
-void AuraEffect::onUpdate() {
-  auraCounter = (auraCounter + 1) % (auraWidth * 3);  // 3 = R G B
-  int cycleProgress = auraDecrement * (auraCounter % auraWidth);
+void AuraEffect::stepColor() {
+  curColor = *getPaletteColor(paletteCounter);
+  nextColor = *nextPaletteColor(&paletteCounter);
+}
+
+void AuraEffect::postInit() {
+  this->stepColor();
+}
 
+void AuraEffect::onUpdate() {
   // Shift all LEDs left by 1 px
   for (int i = 0; i < NUM_LEDS - 1; i++) {
     leds[i] = CRGB(leds[i + 1].r, leds[i + 1].g, leds[i + 1].b);
@@ -23,14 +30,12 @@ void AuraEffect::onUpdate() {
 
   // Calculate the color for the last LED
   int last = NUM_LEDS - 1;
-  if (auraCounter < auraWidth) {
-    // RED
-    leds[last] = CRGB(MAX_BRIGHTNESS - cycleProgress, cycleProgress, 0);
-  } else if (auraCounter < auraWidth * 2) {
-    // GREEN
-    leds[last] = CRGB(0, MAX_BRIGHTNESS - cycleProgress, cycleProgress);
-  } else {
-    // BLUE
-    leds[last] = CRGB(cycleProgress, 0, MAX_BRIGHTNESS - cycleProgress);
+  leds[last] = blendColor(curColor, nextColor, auraCounter, auraWidth);
+
+  if (auraCounter == (auraWidth - 1)) {
+    this->stepColor();
   }
+
+  // Increment the counter
+  auraCounter = (auraCounter + 1) % auraWidth;
 }

aura.h

@@ -4,8 +4,11 @@
 #include "effect.h"
 
 class AuraEffect : public Effect {
+ private:
+  void stepColor();
  public:
   void onUpdate();
+  void postInit();
   void reset();
 };
 

color.cpp

@@ -0,0 +1,8 @@
+#include "color.h"
+
+CRGB blendColor(CRGB color1, CRGB color2, int dividend, int divisor) {
+  return CRGB(
+    color1.r - color1.r * dividend / divisor + color2.r * dividend / divisor,
+    color1.g - color1.g * dividend / divisor + color2.g * dividend / divisor,
+    color1.b - color1.b * dividend / divisor + color2.b * dividend / divisor);
+}

color.h

@@ -0,0 +1,6 @@
+#ifndef COLOR_H
+#define COLOR_H
+#include "ws2812.h"
+
+CRGB blendColor(CRGB color1, CRGB color2, int dividend, int divisor);
+#endif

effect.h

@@ -15,6 +15,8 @@ class Effect {
   // Load all values from EEPROM
   virtual void loadFromEEPROM(){};
   virtual void writeToEEPROM(){};
+  // Called when everything is loaded from EEPROM (i.e. initialization finished)
+  virtual void postInit(){};
   // Serial command events
   virtual void handleCommand(char *cmdBuf, int len) {};
 };