morningdew76

CRGB ColorFromPalette12(CRGBPalette16 pal, uint16_t index, uint8_t brightness, TBlendType blendType) {
  //index is a 12-bit number, range 0-4095
  
  //uint8_t hi4 = lsrX4(index);
  //uint8_t lo4 = index & 0x0F;
  uint8_t hi4 = (index & 0x0F00) >> 8; //***shift 8 bits to the right instead of 4
  uint8_t lo8 = index & 0xFF; //***keep right 8 bytes instead of right 4 bytes
  
  // const CRGB* entry = &(pal[0]) + hi4;
  // since hi4 is always 0..15, hi4 * sizeof(CRGB) can be a single-byte value,

StefanPetrick

/*
 * A FastLED example showing how to
 * map a virtual 2d matrix onto a circular led setup
 *
 * limitations: works so far only up to 255 leds
 *
 * written by Stefan Petrick 2016
 */

#include "FastLED.h"