PImage photo;

void setup() {
  size(1920, 1281);
  photo = loadImage("czy-psy-sie-poca-min.jpg");

  cw4();
}

void draw() {
 // image(photo, 0, 0);
}


void cw1() {
  photo.loadPixels();
  for (int i = 0; i < photo.pixels.length; i++)
  {

    color c = photo.pixels[i];
    
    photo.pixels[i] = color((red(c)+ green(c) +blue(c)) / 3);
  }
    photo.updatePixels();
}

void cw2() {
  photo.loadPixels();
  for (int i = 0; i < photo.pixels.length; i++)
  {

    color c = photo.pixels[i];
    float a1 = 0.2;
    float a2 = 0.3;
    float a3 = 0.5;
    
    photo.pixels[i] = color(a1 * red(c) + a2* green(c) + a3* blue(c));
  }
    photo.updatePixels();
}

void cw3() {
  photo.loadPixels();
  int a = 5;
  for (int i = 0; i < photo.width; i+=a)
  {
    for (int j = 0; j < photo.height; j+=a) 
    {
      color c = photo.get(i, j); 
      fill(c);
      rect(i, j, a, a);
    }
    
    
  }
    photo.updatePixels();
}

void cw4() {
  photo.loadPixels();
  int a = 3;
  for (int i = 0; i < photo.width; i+=a)
  {
    for (int j = 0; j < photo.height; j+=a) 
    {
      color c = photo.get(i, j); 
      fill(c);
      
      int z = int(random(3));
      
      if (z == 0)
      {
        rect(i, j, a, a);
      } else if (z == 1)
      {
        ellipse(i, j, a, a);
      } else if (z == 2)
      {
        circle(i, j, a);
//        stroke(c);
//        line(i, j, a, a);
      }
    }  
  }
    photo.updatePixels();
}