Homework: Season’s Greetings

// sample code adapted from Pearson (2011)

// coding a fractal structure: self-similarity (Pearson 2011:159-160)

// adding self-reference (Pearson 2011:161-162)

// adding animation (Pearson 2011:163-164)

// adding controls (Pearson 2011:164-165)

// monkeyjack8204@gmail.com, DPD 2020

// 希望創造出一個聖誕節卡片的感覺.綠色但有點噁心

​

let _numChildren = 6;

let _maxLevels = 4;

let _trunk;

​

function setup() {

  createCanvas(windowWidth,windowHeight);

  background(255);

  noFill();

  newTree();

}

​

function draw() {

  frameRate(24);

  background(100);

  _trunk.updateMe(width/2, height/2);

  _trunk.drawMe();

}

​

function newTree() {

  _trunk = new Branch(1, 0, width/2, 50);

  _trunk.drawMe();

}

​

// ========== object =============

class Branch {

  constructor(lev, ind, ex, ey) {

    this.level = lev;

    this.index = ind;

    this.x; this.y; this.endx; this.endy;

    this.stroke = (1/this.level)*10;

    this.alph = 255/this.level; 

    this.len = (1/this.level)*random(200);

    this.lenChange = random(10)-5;

    this.rot = 0; 

    this.rotChange = random(10)-5;

​

    this.children = [];

    if (this.level < _maxLevels) {

      for (let i=0; i<_numChildren; i++) {

        let nb = new Branch(this.level+1, i, 0, 0);

        this.children.push(nb);

      }

    }

​

    this.updateMe(ex, ey);

  }

​

  updateMe(nx, ny) {

    this.x = nx;

    this.y = ny;

    // recalculate end points

    this.rot += this.rotChange;

    this.len -= this.lenChange;

    if (this.len<0 || this.len>200) {

      this.lenChange *= -1;

    }

    let r = radians(this.rot);

    this.endx = this.x + this.len*cos(r);

    this.endy = this.y //+ this.len*sin(r);

​

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

      this.children[i].updateMe(this.endx, this.endy);

    }

  }

​

  drawMe() {

    strokeWeight(1);

    noStroke(205,216,115);

    fill(255, this.alph);

    line(this.x, this.y, this.endx, this.endy);

    ellipse(this.x, this.y, this.len/12, this.len/12);

​

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

      this.children[i].drawMe();

    }

​

    fill(208,59,59,this.alph);

    circle(this.x, this.y, 20);

    fill(144,26,26,this.alph);

    circle(this.x+100, this.y+100, 40);

    fill(255,this.alph);

    //frameRate(4);

    circle(random(0,width),random(0,height),random(0,40));

  }

}

​