fermatSpiral

let a=3.5;
let c=0.05;
let mArray=[];
let n=0;
function setup(){
  createCanvas(windowWidth,windowHeight);
  fill(0);
  stroke(255)
  noFill()
  strokeWeight(0.7);
}

function draw(){
  background(0, 52, 100);
  translate(width/2,height/2);
  t=90*sin(frameCount/500)*sin(frameCount/500);
  fermatSpiral(t)
  for (i=0;i<n;i++){
    push()
    translate(mArray[i][0],mArray[i][1])
    fermatSpiral(abs(t-mArray[i][2]))
    pop()
  }

  push()
  translate(width/2-20,height/2-20)
  scale(0.3,0.3)
  fermatSpiral(10)
  pop()
}

function fermatSpiral(n){
   beginShape()
  for (let i=n;i>0;i=i-c){
    r=a*a*sqrt(i)
    x = r * cos(i);
    y = r * sin(i);
    vertex(x,y)
  }
  endShape()
  push()
  scale(-1,-1)
   beginShape()
  for (let i=n;i>0;i=i-c){
    r=a*a*sqrt(i)
    x = r * cos(i);
    y = r * sin(i);
    vertex(x,y)
  }
  endShape()
  pop()
}

function mousePressed(){
  mArray[n]=[mouseX - width/2,mouseY - height/2,t]
  n=n+1
  if (n>25){
    n=0;
    mArray=[];
  }
}