let fishX = 0;

let fishY = 0;

let fishSpeed = 2;

let dir = 1;

let fishW = 50;

let fishH = 15;

​

function setup(){

  createCanvas(800, 600);

  waterBlue = color("#1772FF");

  fishColor = color("#FFE517");

  background(waterBlue);

  fill(fishColor);

  smooth();

  noStroke();

}

​

function draw(){

  background(waterBlue);

​

  // Figure out the new x, y position of the fish.

  fishX += (dir * fishSpeed);

  // If fish hits the edge of the screen, change direction

  if(fishX < 0 || fishX > width){

    dir = -dir;

    fishX += (dir * fishSpeed);

  }

  // Fish will just sort of bob up and down as it moves.

  fishY = height / 2 + sin(radians(frameCount * 2)) * 40;

  // Adjust the height positive or negative depending on the direction

  fishW = 50 * dir;

  // Draw the fish.

  fill(fishColor);

  triangle(fishX, fishY, fishX - fishW, fishY - fishH, fishX - fishW, fishY + fishH);

  fill(255);

  ellipse(fishX - (20 * dir), fishY, 10, 10);  

  fill(0);

  ellipse(fishX - (15 * dir), fishY, 5, 5);

}

​

​

​

​