Merge pull request #346 from adafruit/pb-str2order

Add str2order()

Adafruit_NeoPixel.cpp

@@ -3439,3 +3439,36 @@ void Adafruit_NeoPixel::rainbow(uint16_t first_hue, int8_t reps,
     setPixelColor(i, color);
   }
 }
+
+/*!
+  @brief  Convert pixel color order from string (e.g. "BGR") to NeoPixel
+          color order constant (e.g. NEO_BGR). This may be helpful for code
+          that initializes from text configuration rather than compile-time
+          constants.
+  @param   v  Input string. Should be reasonably sanitized (a 3- or 4-
+              character NUL-terminated string) or undefined behavior may
+              result (output is still a valid NeoPixel order constant, but
+              might not present as expected). Garbage in, garbage out.
+  @return  One of the NeoPixel color order constants (e.g. NEO_BGR).
+           NEO_KHZ400 or NEO_KHZ800 bits are not included, nor needed (all
+           NeoPixels actually support 800 KHz it's been found, and this is
+           the default state if no KHZ bits set).
+  @note    This function is declared static in the class so it can be called
+           without a NeoPixel object (since it's not likely been declared
+           in the code yet). Use Adafruit_NeoPixel::str2order().
+*/
+neoPixelType Adafruit_NeoPixel::str2order(const char *v) {
+  int8_t r = 0, g = 0, b = 0, w = -1;
+  if (v) {
+    char c;
+    for (uint8_t i=0; ((c = tolower(v[i]))); i++) {
+      if (c == 'r') r = i;
+      else if (c == 'g') g = i;
+      else if (c == 'b') b = i;
+      else if (c == 'w') w = i;
+    }
+    r &= 3;
+  }
+  if (w < 0) w = r; // If 'w' not specified, duplicate r bits
+  return (w << 6) | (r << 4) | ((g & 3) << 2) | (b & 3);
+} 

Adafruit_NeoPixel.h

@@ -87,7 +87,7 @@
 // 0bRRRRGGBB for RGB
 
 // RGB NeoPixel permutations; white and red offsets are always same
-// Offset:         W        R        G        B
+// Offset:        W          R          G          B
 #define NEO_RGB ((0 << 6) | (0 << 4) | (1 << 2) | (2)) ///< Transmit as R,G,B
 #define NEO_RBG ((0 << 6) | (0 << 4) | (2 << 2) | (1)) ///< Transmit as R,B,G
 #define NEO_GRB ((1 << 6) | (1 << 4) | (0 << 2) | (2)) ///< Transmit as G,R,B
@@ -371,6 +371,8 @@ class Adafruit_NeoPixel {
                uint8_t saturation = 255, uint8_t brightness = 255,
                bool gammify = true);
 
+  static neoPixelType str2order(const char *v);
+
 private:
 #if defined(ARDUINO_ARCH_RP2040)
   void  rp2040Init(uint8_t pin, bool is800KHz);

library.properties

@@ -1,5 +1,5 @@
 name=Adafruit NeoPixel
-version=1.10.7
+version=1.11.0
 author=Adafruit
 maintainer=Adafruit <info@adafruit.com>
 sentence=Arduino library for controlling single-wire-based LED pixels and strip.