let y = 200;

let w = 40;

let h = 40;

let xjump = 3;

let yjump = 5;

​

function setup() {

  createCanvas(400,400);

}

​

function draw() {

  background(100);

  colorMode(HSB);

  strokeWeight(3);

  stroke(

    map(x,0,width,0,360),

    map(mouseX,0,width,0,100),

    map(y,0,height,0,100)

  );

  rect(x,y,w,h);

//   crazy movement  

//    x = x + random(-30, 30);

//    y = y + random( -30, 30);

//    if(x > width || y > height || x < 0 || y < 0){

//     x = 20;

//     y = 20;}

​

  x = x + xjump;

  y = y + yjump;

if(x >= width || x <= 0){

  xjump = xjump * -1;

  fill(180, 80, random(255))

  }

if(y >= height || y <= 0){

    yjump = yjump * -1;

  fill(330, 80, random(255))

  } 

}