#include <Adafruit_GFX.h>
#include <Adafruit_NeoMatrix.h>
#include <Adafruit_NeoPixel.h>

#define PIN 3

const int matrixWidth = 8;
const int matrixHeight = 8;
const int tileWidth = 4;
const int tileHeight = 1;

const int screenWidth = matrixWidth * tileWidth;
const int screenHeight = matrixHeight * tileHeight;

Adafruit_NeoMatrix screen = Adafruit_NeoMatrix(
  matrixWidth,
  matrixHeight,
  tileWidth,
  tileHeight,
  PIN,
  NEO_TILE_TOP   + NEO_TILE_LEFT   + NEO_TILE_ROWS   + NEO_TILE_PROGRESSIVE +
  NEO_MATRIX_TOP + NEO_MATRIX_LEFT + NEO_MATRIX_ROWS + NEO_MATRIX_PROGRESSIVE,
  NEO_GRBW + NEO_KHZ800);

void setup() {
  screen.begin();
  screen.setBrightness(1);
  screen.clear();
  screen.show();
  startRoutine();
}

int x = 0;
int y = 0;

void loop() {
  
 if (x < screenWidth) {
  x++;
 } else {
  y++;
  x = 0;
  if (y >= screenHeight) {
    y = 0;
    screen.clear();
    screen.show();
  }
 }
 
 screen.drawPixel(x, y, 
  screen.Color(random(100, 255), random(100, 255), random(100, 255)));
  screen.show();
}








void startRoutine() {
  screen.clear();
  for (int i = 0; i < screenHeight; i++) {
    for (int k = 0; k < screenWidth; k += 2) {
      screen.drawPixel(k, i, screen.Color(255, 255, 255));      
      screen.show();
    }
  }

  for (int i = 0; i < screenHeight; i++) {
    for (int k = 0; k < screenWidth; k += 2) {
      screen.drawPixel(k, i, screen.Color(0, 0, 0));
      screen.show();
    }
  }
}