First Water and sky code

Water and sky1

PImage sea2;
PImage sky1;
PImage fish;
PImage birds;

float x;
float y1;
float y2;

ArrayList<PImage> fishImg;
ArrayList<PImage> birdImg;
float position1[][];
float position2[][];
int count1;
int count2;

void setup()
{
  size(800, 520);

  fish = loadImage("fish.png");
  birds = loadImage("bird.png");
  sea2 = loadImage("sea2.png");
  sky1 = loadImage("sky1.png");

  fishImg = new ArrayList<PImage>();
  birdImg = new ArrayList<PImage>();

  position1 = new float[200][2];
  position2 = new float[200][2];

  smooth();

  //y1 = random(0, height/2);
  //y2 = random(height/2, height);
}

void draw()
{
  background(0);

  image(sky1, 0, 0);
  image(sea2, 0, height/2);

  for (int x = 0; x < fishImg.size (); x++)
  {
    image(fishImg.get(x), position2[x][0], position2[x][1]);
    position2[x][0] = position2[x][0] + 1;
  }

  for (int x = 0; x < birdImg.size (); x++)
  {
    image(birdImg.get(x), position1[x][0], position1[x][1]);
    position1[x][0] = position1[x][0] + 1;
  }
}

void mousePressed()
{
  //birdImg.add(new bird);
  x = mouseX;
  y1 = mouseY;
  y2 = mouseY;

  if (mouseY <= (height / 2 - 50))
  {
    birdImg.add(count1, birds);
    position1[count1][0] = x;
    position1[count1][1] = y1;
    count1++;
  } 
  if (mouseY > height /2)
  {
    fishImg.add(count2, fish);
    position2[count2][0] = x;
    position2[count2][1] = y2;
    count2++;
  }
}