Make rainbow effects more colorful

wled00/FX_fcn.cpp

@@ -1022,20 +1022,38 @@ void Segment::blur(uint8_t blur_amount) {
 /*
  * Put a value 0 to 255 in to get a color value.
  * The colours are a transition r -> g -> b -> back to r
- * Inspired by the Adafruit examples.
  */
 uint32_t Segment::color_wheel(uint8_t pos) {
   if (palette) return color_from_palette(pos, false, true, 0);
   uint8_t w = W(currentColor(0));
-  pos = 255 - pos;
-  if (pos < 85) {
-    return RGBW32((255 - pos * 3), 0, (pos * 3), w);
-  } else if(pos < 170) {
-    pos -= 85;
-    return RGBW32(0, (pos * 3), (255 - pos * 3), w);
+  if (useAltWheel) {
+    // by @TripleWhy https://github.com/Aircoookie/WLED/pull/3681 (https://github.com/TripleWhy)
+    // Rotates the color in HSV space, where pos is H. (0=0deg, 256=360deg)
+    // These h and f values are the same h and f you have in the regular HSV to RGB conversion.
+    // The whole funciton really is just a HSV conversion, but assuming H=pos, S=1 and V=1.
+    const uint32_t h = (pos * 3) / 128;
+    const uint32_t f = (pos * 6) % 256;
+    switch (h) {
+      case 0: return RGBW32(255    , f      , 0      , w);
+      case 1: return RGBW32(255 - f, 255    , 0      , w);
+      case 2: return RGBW32(0      , 255    , f      , w);
+      case 3: return RGBW32(0      , 255 - f, 255    , w);
+      case 4: return RGBW32(f      , 0      , 255    , w);
+      case 5: return RGBW32(255    , 0      , 255 - f, w);
+      default: return 0;
+    }
   } else {
-    pos -= 170;
-    return RGBW32((pos * 3), (255 - pos * 3), 0, w);
+    // Inspired by the Adafruit examples.
+    pos = 255 - pos;
+    if (pos < 85) {
+      return RGBW32((255 - pos * 3), 0, (pos * 3), w);
+    } else if(pos < 170) {
+      pos -= 85;
+      return RGBW32(0, (pos * 3), (255 - pos * 3), w);
+    } else {
+      pos -= 170;
+      return RGBW32((pos * 3), (255 - pos * 3), 0, w);
+    }
   }
 }
 

wled00/cfg.cpp

@@ -315,7 +315,7 @@ bool deserializeConfig(JsonObject doc, bool fromFS) {
   if (serialBaud < 96 || serialBaud > 15000) serialBaud = 1152;
   updateBaudRate(serialBaud *100);
 
-  JsonArray hw_if_i2c = hw[F("if")][F("i2c-pin")];
+  JsonArray hw_if_i2c = hw["if"][F("i2c-pin")];
   CJSON(i2c_sda, hw_if_i2c[0]);
   CJSON(i2c_scl, hw_if_i2c[1]);
   PinManagerPinType i2c[2] = { { i2c_sda, true }, { i2c_scl, true } };
@@ -330,7 +330,7 @@ bool deserializeConfig(JsonObject doc, bool fromFS) {
     i2c_sda = -1;
     i2c_scl = -1;
   }
-  JsonArray hw_if_spi = hw[F("if")][F("spi-pin")];
+  JsonArray hw_if_spi = hw["if"][F("spi-pin")];
   CJSON(spi_mosi, hw_if_spi[0]);
   CJSON(spi_sclk, hw_if_spi[1]);
   CJSON(spi_miso, hw_if_spi[2]);
@@ -353,6 +353,7 @@ bool deserializeConfig(JsonObject doc, bool fromFS) {
   CJSON(briMultiplier, light[F("scale-bri")]);
   CJSON(strip.paletteBlend, light[F("pal-mode")]);
   CJSON(autoSegments, light[F("aseg")]);
+  CJSON(useAltWheel, light[F("alt-wheel")]);
 
   CJSON(gammaCorrectVal, light["gc"]["val"]); // default 2.8
   float light_gc_bri = light["gc"]["bri"];
@@ -821,7 +822,7 @@ void serializeConfig() {
 
   hw[F("baud")] = serialBaud;
 
-  JsonObject hw_if = hw.createNestedObject(F("if"));
+  JsonObject hw_if = hw.createNestedObject("if");
   JsonArray hw_if_i2c = hw_if.createNestedArray("i2c-pin");
   hw_if_i2c.add(i2c_sda);
   hw_if_i2c.add(i2c_scl);
@@ -837,6 +838,7 @@ void serializeConfig() {
   light[F("scale-bri")] = briMultiplier;
   light[F("pal-mode")] = strip.paletteBlend;
   light[F("aseg")] = autoSegments;
+  light[F("alt-wheel")] = useAltWheel;
 
   JsonObject light_gc = light.createNestedObject("gc");
   light_gc["bri"] = (gammaCorrectBri) ? gammaCorrectVal : 1.0f;  // keep compatibility

wled00/colors.cpp

@@ -93,13 +93,13 @@ void setRandomColor(byte* rgb)
 
 void colorHStoRGB(uint16_t hue, byte sat, byte* rgb) //hue, sat to rgb
 {
-  float h = ((float)hue)/65535.0f;
+  float h = ((float)hue)/10922.5f; // hue*6/65535
   float s = ((float)sat)/255.0f;
-  int   i = floorf(h*6);
-  float f = h * 6.0f - i;
+  int   i = int(h);
+  float f = h - i;
   int   p = int(255.0f * (1.0f-s));
-  int   q = int(255.0f * (1.0f-f*s));
-  int   t = int(255.0f * (1.0f-(1.0f-f)*s));
+  int   q = int(255.0f * (1.0f-s*f));
+  int   t = int(255.0f * (1.0f-s*(1.0f-f)));
   p = constrain(p, 0, 255);
   q = constrain(q, 0, 255);
   t = constrain(t, 0, 255);

wled00/data/settings_leds.htm

@@ -881,6 +881,7 @@ <h3>Advanced</h3>
 			<option value="2">Linear (never wrap)</option>
 			<option value="3">None (not recommended)</option>
 		</select><br>
+		Alt color wheel: <input type="checkbox" name="ACW"><br>
 		Target refresh rate: <input type="number" class="s" min="1" max="120" name="FR" required> FPS
 		<hr class="sml">
 		<div id="cfg">Config template: <input type="file" name="data2" accept=".json"><button type="button" class="sml" onclick="loadCfg(d.Sf.data2)">Apply</button><br></div>

wled00/set.cpp

@@ -286,6 +286,7 @@ void handleSettingsSet(AsyncWebServerRequest *request, byte subPage)
     strip.paletteFade = request->hasArg(F("PF"));
     t = request->arg(F("TP")).toInt();
     randomPaletteChangeTime = MIN(255,MAX(1,t));
+    useAltWheel = request->hasArg(F("ACW"));
 
     nightlightTargetBri = request->arg(F("TB")).toInt();
     t = request->arg(F("TL")).toInt();

wled00/wled.h

@@ -347,6 +347,7 @@ WLED_GLOBAL bool cctFromRgb         _INIT(false); // CCT is calculated from RGB
 WLED_GLOBAL bool gammaCorrectCol    _INIT(true);  // use gamma correction on colors
 WLED_GLOBAL bool gammaCorrectBri    _INIT(false); // use gamma correction on brightness
 WLED_GLOBAL float gammaCorrectVal   _INIT(2.8f);  // gamma correction value
+WLED_GLOBAL bool useAltWheel        _INIT(false); // alternate method for calculating Segment::color_wheel()
 
 WLED_GLOBAL byte col[]    _INIT_N(({ 255, 160, 0, 0 }));  // current RGB(W) primary color. col[] should be updated if you want to change the color.
 WLED_GLOBAL byte colSec[] _INIT_N(({ 0, 0, 0, 0 }));      // current RGB(W) secondary color

wled00/xml.cpp

@@ -461,6 +461,7 @@ void getSettingsJS(byte subPage, char* dest)
     sappend('v',SET_F("IR"),irPin);
     sappend('v',SET_F("IT"),irEnabled);
     sappend('c',SET_F("MSO"),!irApplyToAllSelected);
+    sappend('c',SET_F("ACW"),useAltWheel);
   }
 
   if (subPage == SUBPAGE_UI)