const curr = "F(F)F(F)F(F)F(FF)FF(F)F(F)F(FF)F(F)F(F)F(F)F(F)F(F)[+F(F)F(F)F(F)F(F)[-F(F)F(F)[+F(FF)F(F)[+F(F)[+(F[+X][--X]FX)][-(F[+X][-X]FX)]F(F)(F[+X][-X]FA)][-F(F)[-(F[+X][-X]FX)]F(F)(F[+X][-X]FB)]F(F)F(F)F(F)[+(F[+X]FX)][-(F[+X][-X]FB)]F(F)(F[+X][-X]FA)][-F(F)F(F)[+F(F)[+(F[++X][-X]FX)][-(F[+X][-X]FX)]F(F)A][-F(F)[+(F[+X][-X]FX)][-(F[+X][-X]FA)]F(F)B]F(F)F(F)F(F)[+(F[++X][-X]FX)][-(F[+X][-X]FX)]F(F)(F[+X][-X]FX)]F(F)F(F)F(F)F(F)F(F)F[+F(F)[+(F[+X][--X]FX)][-(F[+X][-X]FX)]F(F)(F[+X][-X]FX)][-F[+(F[++X][-X]FX)][-(F[+X][-X]FB)]F(F)(F[+X][-X]FX)]FF(F)F(F)[-(F[+X][-X]FX)]F(F)(F[+X][-X]FA)]F(F)FF(F)F(F)F(F)F(F)FF(F)F(F)F(F)F(F)F(F)F(F)F(F)[+F(F)F(F)F[+F(F)[++(F[+X][-X]FA)][-(F[+X][--X]FX)]F(F)(F[+X][-X]FX)][-F(F)[+(F[+X][--X]FX)][-(F[+X][-X]FX)]F(F)(F[+X][-X]FX)]F(F)F(F)B][-F(F)F(F)[+F(F)[+(F[++X][-X]FX)][-(F[+X][-X]FX)]F(FF)(F[++X][-X]FX)][--F(F)[+(F[-X]FX)][-(F[+X][-X]FA)]F(F)A]F(F)F(F)F(F)[+(F[+X][-X]FX)][-(F[+X][-X]FX)]F(F)A]F(F)FF(F)F(F)F(F)F(F)[+F(F)[+(F[+X]FX)][-(F[+X][-X]FX)]F(F)(F[+X][-X]FX)][-F(F)[+(F[++X][-X]FX)][-(F[+X][-X]FB)]F(F)(F[+X][-X]FA)]F(F)F(F)F(F)[+(F[+X][-X]FX)][-(F[+X][-X]FA)]F(F)(F[+X][-X]FX)][-F(F)F(F)F(F)F(F)F(F)F(F)F(F)F(F)[+F(F)F(F)F(F)[+FF(F)[+F(F)[+(F[-X]FX)][-(F[+X][-X]FX)]F(F)(F[+X][-X]FX)][-F(F)[+(F[+X][-X]FX)][-(F[++X][-X]FX)]F(F)B]F(F)F(F)A][-F(F)[+F(F)[+(F[+X][--X]FX)][-(F[+X][--X]FX)]F(FF)(F[+X][-X]FB)][-F(F)[++(F[+X][-X]FX)][-(F[+X][-X]FA)]F(F)(F[+X][-X]FX)]FF(F)B]F(F)F(F)F(F)F(F)F(F)F(F)[+F(F)[+(F[+X][--X]FX)][-(F[-X]FX)]F(F)(F[+X][-X]FB)][-F(F)[+(F[+X][-X]FX)][-(F[+X][-X]FX)]F(F)(F[+X]FX)]F(F)FF(F)[+(F[+X][-X]FB)][-(F[+X][-X]FA)]F(F)B][-F(F)F(F)F(F)F[+FF(F)[-F(F)[++(F[+X][-X]FX)][-(F[++X][-X]FX)]F(F)(F[+X][-X]FX)]FF(F)[+(F[+X][-X]FB)][-(F[+X][-X]FX)]F(F)(F[+X][-X]FX)][-F(F)[+F(F)[+(F[+X][-X]FX)][-(F[+X][-X]FB)]F(F)(F[+X][--X]FX)][-F(F)[+(F[+X][-X]FX)][-(F[+X][-X]FX)]F(F)(F[+X][-X]FX)]F(F)F(F)F(F)F[+(F[+X][-X]FX)][-(F[-X]FX)]F(F)(F[+X][-X]FX)]F(F)F(F)F(FF)[+F(F)[+(F[+X]FX)][-(F[+X][-X]FX)]F(F)A][-F(F)[+(F[-X]FX)][-(F[+X][-X]FX)]F(F)(F[+X][-X]FX)]F(F)F(F)F(F)[+(F[+X][-X]FX)][-(F[+X][-X]FA)]F(F)(F[+X][--X]FX)]F(F)F(F)F(F)F(F)F(F)F(F)F(F)FB]F(F)F(F)FF(FF)F(F)F(F)F(F)F(F)FF(F)F(F)F(F)F(F)FF(F)F(F)F(F)F(F)FF(F)F(F)F(F)F(F)F(F)F(F)[+F(F)F(F)F(F)[+F(F)F(F)[+F(F)[+(F[++X][-X]FX)][-(F[+X][-X]FX)]F(F)(F[-X]FX)][-F(F)[++(F[+X][-X]FB)][-(F[+X][-X]FX)]F(F[++X][-X]FX)]F(F)F(F)F(F)[++(F[+X][-X]FA)][-(F[+X][--X]FX)]F(F)(F[+X][-X]FX)][-FF(F)[+F(FF)[-(F[+X][-X]FB)]F(F)(F[+X][-X]FX)][-F(F)[+(F[+X][-X]FA)][-(F[+X][-X]FB)]F(F)(F[+X][-X]FA)]F(F)F(F)F(F)[+(F[+X][-X]FX)][-(F[-X]FX)]F(F)B]F(F)F(F)F(F)F(F)F(F)F(F)[+F(F)[+(F[+X][-X]FX)][-(F[++X][-X]FX)]F(F)A]F(F)F(F)F(F)[++(F[+X][-X]FX)][-(F[+X][-X]FX)]F(F)(F[+X]FX)][--FF(F)F(F)F(F)[+F(F)F(F)[+F(F)[+(F[++X][-X]FX)][-(F[+X][-X]FB)]F(F)(F[+X][-X]FB)][-F(F)[+(F[-X]FX)][-(F[+X][-X]FA)]F(F)(F[+X][-X]FX)]F(F)F(F)F(F)[+(F[+X]FX)][-(F[+X][-X]FX)]F(F)(F[+X][--X]FX)][-F(F)F(F)[+F(F)[+(F[+X][-X]FB)][-(F[+X][-X]FX)]FB][-F(F)[+(F[+X]FX)][-(F[+X][-X]FX)]F(F)A]FF(F)F(F)[+(F[+X][-X]FB)][-(F[+X][-X]FX)]F(F)A]F(F)FF(F)F(F)F(F)F(FF)[+F[+(F[+X][-X]FX)][-(F[+X][--X]FX)]F(F)B][-F(F)[+(F[+X][-X]FX)][-(F[+X][-X]FX)]F(F[+X][--X]FX)]F(FF)B]F(F)F(F)F(F)F(F)F(F)F(F)F(F)FFF(F)F(FF)F[-F(F)F(F)[+F(F)[+(F[+X][-X]FX)][-(F[+X][-X]FX)]F(F)(F[+X][-X]FX)][-F(F)[+(F[+X][-X]FA)][-(F[+X][-X]FX)]F(F)A]F(F)FF[+(F[-X]FX)][-(F[+X][-X]FA)]F(FF)(F[+X][-X]FX)]F(F)F(F)F(FF)F(F)F(F)[+F(F)[+(F[+X][-X]FX)][-(F[+X][-X]FX)]F(F)(F[+X][-X]FX)][-F(F)[+(F[+X][-X]FX)][-(F[+X][-X]FA)]F(F)(F[+X][-X]FX)]F(F)F(F)B";

​

const len = 8;

const ang = 25;

​

let drawRules;

​

const dur = 6;

​

function setup() {

  createCanvas(1920, 1080);

  strokeWeight(2);

  drawRules = {

    "A": (amt) => {

      // Draw circle at current location

      noStroke();

      fill("#E5CEDC");

      circle(0, 0, len*2 * amt);

    },  

    "B": (amt) => {

      // Draw circle at current location

      noStroke();

      fill("#FCA17D");

      circle(0, 0, len*2 * amt);

    },

    "F": (amt) => {

      // Draw line forward, then move to end of line

      stroke("#9ea93f");

      line(0, 0, 0, -len * amt);

      translate(0, -len * amt);

    },

    "+": (amt) => {

      // Rotate right

      rotate(PI/180 * -ang * amt);

    },

    "-": (amt) => {

      // Rotate right

      rotate(PI/180 * ang * amt);

    },

    // Save current location

    "[": push,

    // Restore last location

    "]": pop,

  };

  // noLoop();

  textAlign(LEFT, CENTER);

  textSize(85);

}

​

function draw() {

  background(28);

  // const amt = 0.4;

  const amt = (-1 * cos(TWO_PI * millis()/(1000 * dur)) + 1)/2;

  // const amt = map(mouseX, 0, width, 0, 3);

  drawLsysLerp(width/4, height, prev, 1);

  drawLsysLerp(width* 3/4, height, curr, 1);

  drawLsysLerp(width/2, height, curr, amt);

}

​

function keyPressed() {

  fullscreen(!fullscreen());

}

​

function drawLsysLerp(x, y, state, t) {

  t = constrain(t, 0, 1);

  let lerpOn = false;

  push();

  translate(x, y);

  for(let i = 0; i < state.length; i ++) {

    let c = state[i];

    if(c === "(") {

      lerpOn = true;

      continue;

    }

    if(c === ")") {

      lerpOn = false;

      continue;

    }

    let lerpT = t;

    if(!lerpOn) {

      lerpT = 1;

    }

    if(c in drawRules) {

      drawRules[c](lerpT);

    }  

  }

  pop();

}