Genuary 2025 day 12

// By Roni Kaufman

// https://ronikaufman.github.io

​

// Made for Genuary 2025

// Day 12: Subdivision.

​

const N_FRAMES = 20;

let points;

​

function setup() {

  createCanvas(500, 500);

  frameRate(10);

  noFill();

  stroke(5);

}

​

function draw() {

  background("#fffbe6");

  let t = (frameCount%N_FRAMES)/N_FRAMES;

  createCompo(t);

}

​

function createCompo(t) {

  points = [];

  let nCorners = 4, r = 150, thetaStep = TAU/nCorners;

  let theta0 = t*TAU/nCorners;

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

    let x1 = width/2 + r*cos(i*thetaStep+theta0);

    let y1 = height/2 + r*sin(i*thetaStep+theta0);

    let x2 = width/2 + r*cos((i+1)*thetaStep+theta0);

    let y2 = height/2 + r*sin((i+1)*thetaStep+theta0);

    let nPoints = 40;

    for (let j = 0; j < nPoints; j++) {

      let t = j/nPoints;

      let x = (1-t)*x1 + t*x2;

      let y = (1-t)*y1 + t*y2;

      points.push({x: x, y: y});

    }

  }

  subdivide({

    x: 1/2,

    y: 1/2,

    w: width-1,

    h: height-1,

    contains: [...Array(points.length).keys()]

  }, random() < 1/2);

}

​

function subdivide({x: x, y: y, w: w, h: h, contains: contains}, horizontally) {

  let rectangle1, rectangle2;

  if (horizontally) {

    let w1 = random(w/4, 3*w/4), w2 = w-w1;

    let x1 = x, x2 = x+w1;

    rectangle1 = {x: x1, y: y, w: w1, h: h, contains: []};

    rectangle2 = {x: x2, y: y, w: w2, h: h, contains: []};

  } else {

    let h1 = random(h/4, 3*h/4), h2 = h-h1;

    let y1 = y, y2 = y+h1;

    rectangle1 = {x: x, y: y1, w: w, h: h1, contains: []};

    rectangle2 = {x: x, y: y2, w: w, h: h2, contains: []};

  }

  for (let idx of contains) {

    if (pointInRectangle(points[idx], rectangle1)) rectangle1.contains.push(idx);

    else rectangle2.contains.push(idx);

  }

  if (rectangle1.contains.length > 1) subdivide(rectangle1, !horizontally);

  else rect(rectangle1.x, rectangle1.y, rectangle1.w, rectangle1.h);

  if (rectangle2.contains.length > 1) subdivide(rectangle2, !horizontally);

  else rect(rectangle2.x, rectangle2.y, rectangle2.w, rectangle2.h);

}

​

function pointInRectangle({x: px, y: py}, {x: rx, y: ry, w: rw, h: rh}) {

  return px > rx && px < rx+rw && py > ry && py < ry+rh;

}