#include <FastLED.h>

#define WIDTH 32
#define HEIGHT 32
#define NUM_LEDS (WIDTH * HEIGHT)

CRGB leds[NUM_LEDS];

void setup() {
  FastLED.addLeds<NEOPIXEL, 3>(leds, NUM_LEDS);
}

void loop()
{
  static uint8_t frame;
  FastLED.clear();
  CRGB *pix = &leds[(frame % HEIGHT) * WIDTH];
  for (byte i = 0; i < WIDTH; i++) {
    *pix++ = CRGB::White;
  }

  FastLED.show();
  frame++;
  // delay(20);
}