Merge pull request #43 from adafruit/pb-swirl

Add rainbow() fill function for easy color swirl

Author: PaintYourDragon

Adafruit_DotStar.cpp

@@ -636,3 +636,33 @@ uint32_t Adafruit_DotStar::gamma32(uint32_t x) {
     y[i] = gamma8(y[i]);
   return x; // Packed 32-bit return
 }
+
+/*!
+  @brief   Fill DotStar strip with one or more cycles of hues.
+           Everyone loves the rainbow swirl so much, now it's canon!
+  @param   first_hue   Hue of first pixel, 0-65535, representing one full
+                       cycle of the color wheel. Each subsequent pixel will
+                       be offset to complete one or more cycles over the
+                       length of the strip.
+  @param   reps        Number of cycles of the color wheel over the length
+                       of the strip. Default is 1. Negative values can be
+                       used to reverse the hue order.
+  @param   saturation  Saturation (optional), 0-255 = gray to pure hue,
+                       default = 255.
+  @param   brightness  Brightness/value (optional), 0-255 = off to max,
+                       default = 255. This is distinct and in combination
+                       with any configured global strip brightness.
+  @param   gammify     If true (default), apply gamma correction to colors
+                       for better appearance.
+*/
+void Adafruit_DotStar::rainbow(uint16_t first_hue, int8_t reps,
+                               uint8_t saturation, uint8_t brightness,
+                               bool gammify) {
+  for (uint16_t i = 0; i < numLEDs; i++) {
+    uint16_t hue = first_hue + (i * reps * 65536) / numLEDs;
+    uint32_t color = ColorHSV(hue, saturation, brightness);
+    if (gammify)
+      color = gamma32(color);
+    setPixelColor(i, color);
+  }
+}

Adafruit_DotStar.h

@@ -186,6 +186,10 @@ class Adafruit_DotStar {
   static uint32_t ColorHSV(uint16_t hue, uint8_t sat = 255, uint8_t val = 255);
   static uint32_t gamma32(uint32_t x);
 
+  void rainbow(uint16_t first_hue = 0, int8_t reps = 1,
+               uint8_t saturation = 255, uint8_t brightness = 255,
+               boolean gammify = true);
+
 private:
   uint16_t numLEDs;   ///< Number of pixels
   uint8_t dataPin;    ///< If soft SPI, data pin #

library.properties

@@ -1,5 +1,5 @@
 name=Adafruit DotStar
-version=1.1.4
+version=1.1.5
 author=Adafruit
 maintainer=Adafruit <info@adafruit.com>
 sentence=Adafruit DotStar LED Library