let angle = 0;

let outer_radius = 250;

let initial_radius = 5;

​

​

​

function setup() {

  createCanvas(1000, 1000);

  fill(0);

}

​

function draw() {

  draw_Fermat_spiral();

​

}

​

function draw_Fermat_spiral()

{

  // Co-ordinates of spiral ball which is determined by the position of cursor

  let x_val = cos(angle) * outer_radius + mouseX;

  let y_val = sin(angle) * outer_radius + mouseY;

​

  // Drawing the ball

  stroke(10);

  fill(255,242,229);

  ellipse(x_val, y_val, initial_radius, initial_radius);

  // Updating parameters required to determine x_val and y_val

  angle = angle - 1;;

  outer_radius = outer_radius - 0.5;

  // As long as the ball co-incides with the cursor, change the background 

//   if (x_val === mouseX && y_val === mouseY)

//     background(255, 0, 0);

//   // If the ball goes out of canvas, update angle, x_val and y_val accordingly

//   if (x_val < 0 || x_val > width || y_val < 0 || y_val >height)

//   {

//     angle = 0;

//     x_val = mouseX;

//     y_val = mouseY;

//   }

​

}