​

var cellSize = 12;

var wireLength = 30;

var cutOffLength = 2;

var straightness = 5;

var grid = [];

var gridWidth, gridHeight;

var available = [];

var wires = [];

var strokeColor = 80;

var cellColor = 30;

​

var dirs = [

  [-1, -1],

  [0, -1],

  [1, -1],

  [1, 0],

  [1, 1],

  [0, 1],

  [-1, 1],

  [-1, 0]

];

​

function Cell(x, y) {

  this.x = x;

  this.y = y;

  this.available = true;

}

​

function Wire(start) {

  this.cells = [];

  this.cells.push(start);

  this.last = findOpenDir(start.x, start.y);

}

​

Wire.prototype.render = function() {

  noFill();

  strokeWeight(cellSize / 12);

  // stroke color

  stroke(strokeColor, strokeColor, strokeColor);

  beginShape();

  for (var i = 0; i < this.cells.length; i++) {

    var cell = this.cells[i];

    vertex((cell.x + 0.4) * cellSize, (cell.y + 0.4) * cellSize);

  }

  endShape();

  // fill color

  fill(cellColor);

  strokeWeight(cellSize / 12);

  var end = this.cells.length - 1;

  ellipse(

    (this.cells[0].x + 0.4) * cellSize,

    (this.cells[0].y + 0.4) * cellSize,

    cellSize * 0.6,

    cellSize * 0.6

  );

  ellipse(

    (this.cells[end].x + 0.4) * cellSize,

    (this.cells[end].y + 0.4) * cellSize,

    cellSize * 0.6,

    cellSize * 0.6

  );

};

​

Wire.prototype.generate = function() {

  var hasSpace = true;

  while (this.cells.length < wireLength && hasSpace) {

    var prevCell = this.cells[this.cells.length - 1];

    var tries = [0, 1, -1];

    if (random() > 0.5) tries = [0, -1, 1];

    var found = false;

    hasSpace = false;

​

    while (tries.length > 0 && !found) {

      var mod = tries.splice(

        floor(pow(random(), straightness) * tries.length),

        1

      )[0];

      var index = this.last + 4 + mod;

      if (index < 0) index += 8;

      if (index > 7) index -= 8;

      var dir = dirs[index];

​

      var x = dir[0] + prevCell.x;

      var y = dir[1] + prevCell.y;

      if (x >= 0 && x < gridWidth - 1 && y >= 0 && y < gridHeight - 1) {

        var cell = grid[x][y];

        if (cell.available && noCrossOver(index, x, y)) {

          this.cells.push(cell);

          cell.available = false;

          hasSpace = found = true;

          this.last = this.last + mod;

          if (this.last < 0) this.last += 8;

          if (this.last > 7) this.last -= 8;

        }

      }

    }

  }

};

​

function noCrossOver(index, x, y) {

  if (index == 0) return grid[x + 1][y].available || grid[x][y + 1].available;

  if (index == 2) return grid[x - 1][y].available || grid[x][y + 1].available;

  if (index == 4) return grid[x - 1][y].available || grid[x][y - 1].available;

  if (index == 6) return grid[x + 1][y].available || grid[x][y - 1].available;

  return true;

}

​

function findOpenDir(x, y) {

  var checks = [0, 1, 2, 3, 4, 5, 6, 7];

  while (checks.length > 0) {

    var index = checks.splice(floor(random() * checks.length), 1)[0];

    var dir = dirs[index];

    var x2 = x + dirs[0];

    var y2 = y + dirs[1];

    if (x2 >= 0 && x2 < gridWidth - 1 && y2 >= 0 && y2 < gridHeight - 1) {

      if (grid[x2][y2].available) return index;

    }

  }

  return 0;

}

​

function setup() {

  createCanvas(2000, 2000, SVG);

  // createCanvas();

​

  ellipseMode(CENTER);

  // color mode

  colorMode(RGB, 255, 255, 255);

​

  var gui = new dat.GUI();

  gui.add(this, "cellSize", 10, 80, 1);

  gui.add(this, "wireLength", 1, 100, 1);

  gui.add(this, "cutOffLength", 0, 5, 1);

  gui.add(this, "straightness", 0.01, 20, 0.01);

  gui.add(this, "recreate");

​

  resize();

  print("setup");

}

​

function recreate() {

  gridWidth = ceil(width / cellSize) + 1;

  gridHeight = ceil(height / cellSize) + 1;

  grid = [];

  available = [];

  wires = [];

​

  for (var i = 0; i < gridWidth; i++) {

    grid.push([]);

    for (var j = 0; j < gridHeight; j++) {

      var cell = new Cell(i, j);

      grid[i][j] = cell;

      available.push(cell);

    }

  }

​

  while (available.length > 0) {

    var cell = available[floor(random() * available.length)];

    cell.available = false;

    var wire = new Wire(cell);

    wire.generate();

    wires.push(wire);

    for (var i = 0; i < wire.cells.length; i++) {

      available.splice(available.indexOf(wire.cells[i]), 1);

    }

  }

  loop();

}

​

function draw() {

  // background color

  background(0, 0, 0);

  if (grid == undefined) return;

​

  for (var i = 0; i < wires.length; i++) {

    if (wires[i].cells.length > cutOffLength) wires[i].render();

  }

  noLoop();

  print("draw");

}

​

function resize() {

  resizeCanvas(window.innerWidth, window.innerHeight);

  recreate();

  print("recreate");

  save("mySVG.svg"); // give file name

  print("saved svg");

  noLoop(); // we just want to export once

}