011

script.js

let startX;
let startY;

let possibleDirections = [];

const mod = 20;

let points = [];

function setup() {

  createCanvas(600, 600);
  background(240);

  // calculates de starting point
  startX = mod * floor(random(1, width / mod));
  startY = mod * floor(random(1, height / mod));

  points.push(new spoint(startX, startY));

  frameRate(12);

  background(240);

  // draw grid points
  grid();

}


function draw() {

  background(240);

  grid();

  for (let i = 0; i < points.length; i++) {
    stroke(0);
    noFill();
    ellipse(points[i].x, points[i].y,10);
  }
  
  noFill();
  beginShape();

  for (let i = 0; i < points.length; i++) {
    vertex(points[i].x, points[i].y);
  }

  endShape();
  nextPoint();
}

function spoint(x, y) {
  this.x = x;
  this.y = y;
}


function grid() {

  strokeWeight(1);
  stroke(100);

  for (let x = mod; x < width; x += mod) {
    for (let y = mod; y < height; y += mod) {
      point(x, y);
    }
  }
}

function keyTyped() {

  if (key === 's') {
    saveCanvas("mssm_01_", 'png');  
  }
}


function nextPoint() {

  checkPossibleDirections();

  if (possibleDirections.length > 0) {
    // random choose a direction
    let direction = possibleDirections[floor(random(0, possibleDirections.length))];
    let newX = 0;
    let newY = 0;

    // based on the direction choosed set the dest vector
    switch (direction) {

      // N
      case 0:
        newX = points[points.length - 1].x;
        newY = points[points.length - 1].y - mod;
        break;

        // NE
      case 1:
        newX = points[points.length - 1].x + mod;
        newY = points[points.length - 1].y - mod;
        break;

        // E
      case 2:
        newX = points[points.length - 1].x + mod;
        newY = points[points.length - 1].y;
        break;

        // SE
      case 3:
        newX = points[points.length - 1].x + mod;
        newY = points[points.length - 1].y + mod;
        break;

        // S
      case 4:
        newX = points[points.length - 1].x;
        newY = points[points.length - 1].y + mod;
        break;

        // SW
      case 5:
        newX = points[points.length - 1].x - mod;
        newY = points[points.length - 1].y + mod;
        break;

        // W
      case 6:
        newX = points[points.length - 1].x - mod;
        newY = points[points.length - 1].y;
        break;

        // NW
      case 7:
        newX = points[points.length - 1].x - mod;
        newY = points[points.length - 1].y - mod;
        break;
    }

    points.push(new spoint(newX, newY));

    possibleDirections = [];

    checkPossibleDirections();

  } else {
   
    console.log('ended');
    
    points = [];
    
    startX = mod * floor(random(1, width / mod));
    startY = mod * floor(random(1, height / mod));

    points.push(new spoint(startX, startY));

  }

}


function checkPossibleDirections() {

  possibleDirections = [];

  // N
  if (points[points.length - 1].y - mod >= mod && checkExistingPoint(points[points.length - 1].x, points[points.length - 1].y - mod)) {
    possibleDirections.push(0);
  }

  // NE
  if (points[points.length - 1].x + mod <= width - mod && points[points.length - 1].y - mod >= mod && checkExistingPoint(points[points.length - 1].x + mod, points[points.length - 1].y - mod)) {
    possibleDirections.push(1);
  }

  // E
  if (points[points.length - 1].x + mod <= width - mod && checkExistingPoint(points[points.length - 1].x + mod, points[points.length - 1].y)) {
    possibleDirections.push(2);
  }

  // SE
  if (points[points.length - 1].x + mod <= width - mod && points[points.length - 1].y + mod <= height - mod && checkExistingPoint(points[points.length - 1].x + mod, points[points.length - 1].y + mod)) {
    possibleDirections.push(3);
  }

  // S
  if (points[points.length - 1].y + mod <= height - mod && checkExistingPoint(points[points.length - 1].x, points[points.length - 1].y + mod)) {
    possibleDirections.push(4);
  }

  // SW
  if (points[points.length - 1].x - mod >= mod && points[points.length - 1].y + mod <= height - mod && checkExistingPoint(points[points.length - 1].x - mod, points[points.length - 1].y + mod)) {
    possibleDirections.push(5);
  }

  // W
  if (points[points.length - 1].x - mod >= mod && checkExistingPoint(points[points.length - 1].x - mod, points[points.length - 1].y)) {
    possibleDirections.push(6);
  }

  // NW
  if (points[points.length - 1].x - mod >= mod && points[points.length - 1].y - mod >= mod && checkExistingPoint(points[points.length - 1].x - mod, points[points.length - 1].y - mod)) {
    possibleDirections.push(7);
  }

}

function checkExistingPoint(x, y) {

  let pointToCheck = createVector(x, y);

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

    let createdPoint = createVector(points[i].x, points[i].y);

    if (pointToCheck.equals(createdPoint)) {
      return false;
    }

  }

  return true;

}

function gradientCircle(x, y, r, c, a){
  
  noStroke();
  
  c.setAlpha(a);
  fill(c);
  
  for(let i = 0; i < r; i++){
    
  	ellipse(x, y, i);
  }
}