Function setup

examples/Fx/FxWater/FxWater.h:33–36

void process_water(uint8_t * src, uint8_t * dst) ;

void setup() {
  Serial.begin(115200);
  FastLED.addLeds<NEOPIXEL, 2>(leds, NUM_LEDS).setScreenMap(WIDTH, HEIGHT);
}

// from: https://github.com/FastLED/FastLED/pull/202
fl::CRGB MyColorFromPaletteExtended(const fl::CRGBPalette16& pal, uint16_t index, uint8_t brightness, TBlendType blendType) {