City Map - OpenProcessing

mySketch
Walker
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let SCL = 3;
let sk_w = SCL*210; // 1920 // width
let sk_h = SCL*297; // 1080 // height
let sk_m = SCL*035; // 100 // margin
let p; 
​
let x1, y1, x2, y2;
let walkers;
​
​
function setup() {
  createCanvas(sk_w, sk_h);
  background(32);
  loop();
  frameRate(60);
  
  // pixel array to check if crossing
  pa = create2DArray(width, height);
​
  // start  point in both directions
  const sx = randomGaussian(width / 2, 50);
  const sy = randomGaussian(height / 2, 50);
  circle(sx, sy, 4)
  
  walkers = []; // initialize street = walkers
  pa[~~sx][~~sy] = 1;
  const NUM = ~~random(2, 5);
  const STA = random(TWO_PI);
  for (let i = 0; i < NUM; i++) {
    const clr = color(random(200), random(100), random(300));
    const ang = STA + i*TWO_PI/NUM + random(-0.3, 0.3)
    walkers.push(new Walker(sx, sy, ang, clr, i));  
  }
  
  // hotspots: higher probability for branches
  x1 = sx; // ~~(random(sk_m, sk_w - sk_m));
  y1 = sy; // ~~(random(sk_m, sk_h - sk_m));
  x2 = ~~(random(sk_m, sk_w - sk_m));
  y2 = ~~(random(sk_m, sk_h - sk_m));
  circle(x1, y1, 4)
  circle(x2, y2, 4)
}
​
​
function draw() {
  background(32);
  
  let isFinished = false;
  let iterations = 3; // to speed up generation
  while (isFinished == false && iterations-- > 0) {
    isFinished = true;
​
    for (let i = walkers.length-1; i >= 0; i--) {
​
      const stp = 1.5;
      if (!walkers[i].update(stp)) {
        walkers.slice(i, 1);
      } else {
        isFinished = false;
      }
​
      walkers[i].show();
    }
  } // while
​
  if (isFinished == true) {
    console.log(`ended: S to save svg, LMB to restart`);
    // console.log(walkers);
    noLoop();
  }
​
  //saveFrame("frames/####.png");
}
​
function create2DArray(rows, cols) {
  return Array.from({ length: rows }, () => Array(cols).fill(0));
}
​
function mousePressed() {
  if (mouseButton !== RIGHT && mouseButton !== CENTER && mouseX >=0 && mouseX < width && mouseY >= 0 && mouseY < height) {
    loop();
    setup();
  }
}
​
function keyPressed() {
  if (key === 's' || key === 'S') {
    let svgStr = `<svg width="${width}" height="${height}" xmlns="http://www.w3.org/2000/svg">\n`;
    
    walkers = walkers.sort((a, b) => a.grp - b.grp);
    let lastGrp = -1;
    for (const street of walkers) {
      if (street.grp != lastGrp) {
        if (lastGrp !== -1) svgStr += `</g>\n`;
        lastGrp = street.grp;
        svgStr += `<g fill="none" stroke="black" stroke-width="1">\n`;
      }
      svgStr += ` <line x1="${nf(street.start.x,0,3)}" y1="${nf(street.start.y,0,3)}" x2="${nf(street.pos.x,0,3)}" y2="${nf(street.pos.y,0,3)}" />\n`;
    }
    svgStr += `</g>\n`;
    
    svgStr += `</svg>`;
    save(svgStr.split("\n"), "epi_city.svg.txt");
  }
}