let previousY;

​

function setup() {

  createCanvas(400, 400);

  background(255);

  previousX = mouseX;

  previousY = mouseY;

  fill("red");

  circle(20,20,40);

}

​

​

​

function draw() {

/* fill(mouseX,mouseY, 60);

  point(mouseX,mouseY, 15);

// circle(mouseX, mouseY, 20);*/

  if (mouseIsPressed){

    line(mouseX, mouseY, previousMouseX,previousMouseY)

 }

previousMouseX = mouseX

previousMouseY = mouseY  

  if(mouseIsPressed && mouseX <= 40 && mouseX > 0 && mouseY > 0 && mouseY <= 40){

    background(255);

      fill("red");

  circle(20,20,40);

  }

}