Add Aurora Borealis effect (#1589)

* Added aurora effect

* Cosmetic changes prior to PR to match some guidelines

* Update FX.cpp

Moved mode_aurora function to end of FX.cpp

* Cosmetic changes prior to PR

- Changed new palette name to have a whitespace
- Undid changes to platformio.ini

* Removed commented out test palette

* Improved memory handling

Use SEGENV to allocate and manage dynamic memory needs of effect.
Only allocate as much memory as needed for current amount of waves set.

* Improvements to Aurora effect

- Smoother on low speed
- CRGB is trivially copiable
- Replaced Red & Blue mode
- Simplified logic and mem use a tiny bit
- Aurora2 palette a bit less yellowish

Co-authored-by: cschwinne <dev.aircoookie@gmail.com>

wled00/FX.cpp

@@ -30,7 +30,6 @@
 #define IBN 5100
 #define PALETTE_SOLID_WRAP (paletteBlend == 1 || paletteBlend == 3)
 
-
 /*
  * No blinking. Just plain old static light.
  */
@@ -1003,14 +1002,6 @@ uint16_t WS2812FX::mode_running_color(void) {
 }
 
 
-/*
- * Alternating red/blue pixels running.
- */
-uint16_t WS2812FX::mode_running_red_blue(void) {
-  return running(RED, BLUE);
-}
-
-
 /*
  * Alternating red/green pixels running.
  */
@@ -3880,3 +3871,153 @@ uint16_t WS2812FX::mode_tv_simulator(void) {
   return FRAMETIME;
   #endif
 }
+
+/*
+  Aurora effect
+*/
+
+//CONFIG
+#define BACKLIGHT 5
+#define W_MAX_COUNT 20            //Number of simultaneous waves
+#define W_MAX_SPEED 6             //Higher number, higher speed
+#define W_WIDTH_FACTOR 6          //Higher number, smaller waves
+
+class AuroraWave {
+  private:
+    uint16_t ttl;
+    CRGB basecolor;
+    float basealpha;
+    uint16_t age;
+    uint16_t width;
+    float center;
+    bool goingleft;
+    float speed_factor;
+    bool alive = true;
+
+  public:
+    void init(uint32_t segment_length, CRGB color) {
+      ttl = random(500, 1501);
+      basecolor = color;
+      basealpha = random(60, 101) / (float)100;
+      age = 0;
+      width = random(segment_length / 20, segment_length / W_WIDTH_FACTOR); //half of width to make math easier
+      if (!width) width = 1;
+      center = random(101) / (float)100 * segment_length;
+      goingleft = random(0, 2) == 0;
+      speed_factor = (random(10, 31) / (float)100 * W_MAX_SPEED / 255);
+      alive = true;
+    }
+
+    CRGB getColorForLED(int ledIndex) {      
+      if(ledIndex < center - width || ledIndex > center + width) return 0; //Position out of range of this wave
+
+      CRGB rgb;
+
+      //Offset of this led from center of wave
+      //The further away from the center, the dimmer the LED
+      float offset = ledIndex - center;
+      if (offset < 0) offset = -offset;
+      float offsetFactor = offset / width;
+
+      //The age of the wave determines it brightness.
+      //At half its maximum age it will be the brightest.
+      float ageFactor = 0.1;        
+      if((float)age / ttl < 0.5) {
+        ageFactor = (float)age / (ttl / 2);
+      } else {
+        ageFactor = (float)(ttl - age) / ((float)ttl * 0.5);
+      }
+
+      //Calculate color based on above factors and basealpha value
+      float factor = (1 - offsetFactor) * ageFactor * basealpha;
+      rgb.r = basecolor.r * factor;
+      rgb.g = basecolor.g * factor;
+      rgb.b = basecolor.b * factor;
+    
+      return rgb;
+    };
+
+    //Change position and age of wave
+    //Determine if its sill "alive"
+    void update(uint32_t segment_length, uint32_t speed) {
+      if(goingleft) {
+        center -= speed_factor * speed;
+      } else {
+        center += speed_factor * speed;
+      }
+
+      age++;
+
+      if(age > ttl) {
+        alive = false;
+      } else {
+        if(goingleft) {
+          if(center + width < 0) {
+            alive = false;
+          }
+        } else {
+          if(center - width > segment_length) {
+            alive = false;
+          }
+        }
+      }
+    };
+
+    bool stillAlive() {
+      return alive;
+    };
+};
+
+uint16_t WS2812FX::mode_aurora(void) {
+  //aux1 = Wavecount
+  //aux2 = Intensity in last loop
+
+  AuroraWave* waves;
+
+  if(SEGENV.aux0 != SEGMENT.intensity || SEGENV.call == 0) {
+    //Intensity slider changed or first call
+    SEGENV.aux1 = ((float)SEGMENT.intensity / 255) * W_MAX_COUNT;
+    SEGENV.aux0 = SEGMENT.intensity;
+
+    if(!SEGENV.allocateData(sizeof(AuroraWave) * SEGENV.aux1)) {
+      return mode_static(); //allocation failed
+    }
+
+    waves = reinterpret_cast<AuroraWave*>(SEGENV.data);
+
+    for(int i = 0; i < SEGENV.aux1; i++) {
+      waves[i].init(SEGLEN, col_to_crgb(color_from_palette(random8(), false, false, random(0, 3))));
+    }
+  } else {
+    waves = reinterpret_cast<AuroraWave*>(SEGENV.data);
+  }
+
+  for(int i = 0; i < SEGENV.aux1; i++) {
+    //Update values of wave
+    waves[i].update(SEGLEN, SEGMENT.speed);
+
+    if(!(waves[i].stillAlive())) {
+      //If a wave dies, reinitialize it starts over.
+      waves[i].init(SEGLEN, col_to_crgb(color_from_palette(random8(), false, false, random(0, 3))));
+    }
+  }
+
+  //Loop through LEDs to determine color
+  for(int i = 0; i < SEGLEN; i++) {    
+    CRGB mixedRgb = CRGB(BACKLIGHT, BACKLIGHT, BACKLIGHT);
+
+    //For each LED we must check each wave if it is "active" at this position.
+    //If there are multiple waves active on a LED we multiply their values.
+    for(int  j = 0; j < SEGENV.aux1; j++) {
+      CRGB rgb = waves[j].getColorForLED(i);
+      
+      if(rgb != CRGB(0)) {       
+        mixedRgb += rgb;
+      }
+    }
+
+    setPixelColor(i, mixedRgb[0], mixedRgb[1], mixedRgb[2], BACKLIGHT);
+  }
+  
+  return FRAMETIME;
+}

wled00/FX.h

@@ -119,7 +119,6 @@
 #define IS_REVERSE      ((SEGMENT.options & REVERSE     ) == REVERSE     )
 #define IS_SELECTED     ((SEGMENT.options & SELECTED    ) == SELECTED    )
 
-
 #define MODE_COUNT  118
 
 #define FX_MODE_STATIC                   0
@@ -160,7 +159,7 @@
 #define FX_MODE_TRAFFIC_LIGHT           35
 #define FX_MODE_COLOR_SWEEP_RANDOM      36
 #define FX_MODE_RUNNING_COLOR           37
-#define FX_MODE_RUNNING_RED_BLUE        38
+#define FX_MODE_AURORA                  38
 #define FX_MODE_RUNNING_RANDOM          39
 #define FX_MODE_LARSON_SCANNER          40
 #define FX_MODE_COMET                   41
@@ -389,7 +388,7 @@ class WS2812FX {
       _mode[FX_MODE_TRAFFIC_LIGHT]           = &WS2812FX::mode_traffic_light;
       _mode[FX_MODE_COLOR_SWEEP_RANDOM]      = &WS2812FX::mode_color_sweep_random;
       _mode[FX_MODE_RUNNING_COLOR]           = &WS2812FX::mode_running_color;
-      _mode[FX_MODE_RUNNING_RED_BLUE]        = &WS2812FX::mode_running_red_blue;
+      _mode[FX_MODE_AURORA]                  = &WS2812FX::mode_aurora;
       _mode[FX_MODE_RUNNING_RANDOM]          = &WS2812FX::mode_running_random;
       _mode[FX_MODE_LARSON_SCANNER]          = &WS2812FX::mode_larson_scanner;
       _mode[FX_MODE_COMET]                   = &WS2812FX::mode_comet;
@@ -603,7 +602,7 @@ class WS2812FX {
       mode_colorful(void),
       mode_traffic_light(void),
       mode_running_color(void),
-      mode_running_red_blue(void),
+      mode_aurora(void),
       mode_running_random(void),
       mode_larson_scanner(void),
       mode_comet(void),
@@ -764,7 +763,7 @@ const char JSON_mode_names[] PROGMEM = R"=====([
 "Solid","Blink","Breathe","Wipe","Wipe Random","Random Colors","Sweep","Dynamic","Colorloop","Rainbow",
 "Scan","Scan Dual","Fade","Theater","Theater Rainbow","Running","Saw","Twinkle","Dissolve","Dissolve Rnd",
 "Sparkle","Sparkle Dark","Sparkle+","Strobe","Strobe Rainbow","Strobe Mega","Blink Rainbow","Android","Chase","Chase Random",
-"Chase Rainbow","Chase Flash","Chase Flash Rnd","Rainbow Runner","Colorful","Traffic Light","Sweep Random","Running 2","Red & Blue","Stream",
+"Chase Rainbow","Chase Flash","Chase Flash Rnd","Rainbow Runner","Colorful","Traffic Light","Sweep Random","Running 2","Aurora","Stream",
 "Scanner","Lighthouse","Fireworks","Rain","Merry Christmas","Fire Flicker","Gradient","Loading","Police","Police All",
 "Two Dots","Two Areas","Circus","Halloween","Tri Chase","Tri Wipe","Tri Fade","Lightning","ICU","Multi Comet",
 "Scanner Dual","Stream 2","Oscillate","Pride 2015","Juggle","Palette","Fire 2012","Colorwaves","Bpm","Fill Noise",
@@ -782,7 +781,7 @@ const char JSON_palette_names[] PROGMEM = R"=====([
 "Pastel","Sunset 2","Beech","Vintage","Departure","Landscape","Beach","Sherbet","Hult","Hult 64",
 "Drywet","Jul","Grintage","Rewhi","Tertiary","Fire","Icefire","Cyane","Light Pink","Autumn",
 "Magenta","Magred","Yelmag","Yelblu","Orange & Teal","Tiamat","April Night","Orangery","C9","Sakura",
-"Aurora","Atlantica","C9 2","C9 New","Temperature"
+"Aurora","Atlantica","C9 2","C9 New","Temperature","Aurora 2"
 ])=====";
 
 #endif

wled00/palettes.h

@@ -13,7 +13,7 @@
 #ifndef PalettesWLED_h
 #define PalettesWLED_h
 
-#define GRADIENT_PALETTE_COUNT 42
+#define GRADIENT_PALETTE_COUNT 43
 
 const byte ib_jul01_gp[] PROGMEM = {
     0, 194,  1,  1,
@@ -631,6 +631,14 @@ const byte temperature_gp[] PROGMEM = {
   240,  80,  3,  3,
   255,  80,  3,  3};
 
+  const byte Aurora2[] PROGMEM = {
+      0,  17, 177,  13,    //Greenish
+     64, 121, 242,   5,    //Greenish
+    128,  25, 173, 121,    //Turquoise
+    192, 250,  77, 127,    //Pink
+    255, 171, 101, 221     //Purple
+  };
+
 // Single array of defined cpt-city color palettes.
 // This will let us programmatically choose one based on
 // a number, rather than having to activate each explicitly
@@ -677,7 +685,8 @@ const byte* const gGradientPalettes[] PROGMEM = {
   Atlantica_gp,                 //51-38 Atlantica
   C9_2_gp,                      //52-39 C9 2
   C9_new_gp,                    //53-40 C9 New
-  temperature_gp                //54-41 Temperature
+  temperature_gp,               //54-41 Temperature
+  Aurora2                       //55-42 Aurora 2
 };
 
 #endif