Vertigo III

/*

 * Reproduction of an alternate movie poster for Vertigo

 * haschdl, 28/04/2018

 * https://haschdl.github.io/generative

 */

var s0 = 450.;

var a0 = 0.08;

var a_coef = 1.00005;

​

​

var s, a,aTotal,mainColor;

​

function setup() {

  createCanvas(450, 450);

  rectMode(CENTER);  

  smooth(8);

  noStroke();

  mainColor = color(195,55,33);

  init();

}

​

function init() {

  background(mainColor);

  s = s0;

  a = a0;

  aTotal=0;

}

​

function draw() {

  if (s<=5) 

    return;

​

  translate(width/2, height / 2);

  rotate(aTotal);

  //alternate colors 

  //between main and black

  if(frameCount % 2 == 0)

    fill(mainColor);

  else fill(0);

  rect(0, 0, s, s );

  //new size of the square 

  //according to rotation angle. 

  //See Github for examplanation:

  s = s / (sin(a) + cos(a));

  //increases the rotation angle by a small amount

  //and accumulates the rotationg angle

  a *= a_coef;

  aTotal+=a;

}

​

function mouseMoved() {

  a0 = map(mouseX, 0, height, .1, .9);

  init();

}

​

function  keyPressed() {

  switch(key) {

    case 's':case'S':

      save(String.format("vertigoIII_a0=%.2f_a_coef=%.2f.png",a0,a_coef));

      println("File saved!");

      break;

    }

}