fourier ? - OpenProcessing

main
utils
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let points = [],
    n_points = 32,
    holding = -1,
    hover = {text: "", timeout: 0},
    sym = false,
    fourier = [],
    n_fourier = 12,
    f_subdivide = 6,
    fourier_avg = 0;
​
function setup() {
  createCanvas(400, 400);
  for(let i=0; i<n_points; i++) points.push(100);
  for(let i=0; i<n_fourier; i++) fourier.push(0);
  textAlign(CENTER, TOP);
}
​
function draw() {
  if(holding >= 0) {
    let f = snap(
      mouseX, mouseY,
      200 + Math.cos(holding/n_points * TWO_PI)*30,  200 + Math.sin(holding/n_points * TWO_PI)*30,
      200 + Math.cos(holding/n_points * TWO_PI)*170, 200 + Math.sin(holding/n_points * TWO_PI)*170
                 );
    f = clp(f*140 + 30, 30, 170);
    points[holding] = f;
    if(sym && holding%(n_points/2) != n_points/4) points[(n_points - holding + n_points/2)%n_points] = f;
  }
  
  tune();
  
  fourier_avg = 0;
  for(let point of points) {
    fourier_avg += point;
  }
  fourier_avg /= n_points;
  
  background(255);
  fill(255); stroke(0, 50);
  for(let i=0; i<n_fourier*f_subdivide; i++) {
    line(200 + Math.cos(i/n_fourier/f_subdivide * TWO_PI)*fo(i/n_fourier/f_subdivide),  200 + Math.sin(i/n_fourier/f_subdivide * TWO_PI)*fo(i/n_fourier/f_subdivide),
         200 + Math.cos((i+1)/n_fourier/f_subdivide * TWO_PI)*fo((i+1)/n_fourier/f_subdivide), 200 + Math.sin((i+1)/n_fourier/f_subdivide * TWO_PI)*fo((i+1)/n_fourier/f_subdivide));
  }
  for(let i=0; i<n_points; i++) {
    line(200 + Math.cos(i/n_points * TWO_PI)*30,  200 + Math.sin(i/n_points * TWO_PI)*30,
         200 + Math.cos(i/n_points * TWO_PI)*170, 200 + Math.sin(i/n_points * TWO_PI)*170);
    ellipse(200 + Math.cos(i/n_points * TWO_PI)*points[i], 200 + Math.sin(i/n_points * TWO_PI)*points[i], 10, 10);
  }
  fill(0, hover.timeout*10); noStroke();
  text(hover.text, 200, 20);
  hover.timeout = Math.max(0, hover.timeout - 1);
}
​
function mousePressed() {
  let min_dist = -1,
      choice = -1;
  for(let i=0; i<n_points; i++) {
    let distance = dst(mouseX, mouseY, 200 + Math.cos(i/n_points * TWO_PI)*points[i], 200 + Math.sin(i/n_points * TWO_PI)*points[i]);
    if(distance < min_dist || min_dist < 0) {
      choice = i;
      min_dist = distance;
    }
  }
  if(min_dist < 20) holding = choice;
}
​
function mouseReleased() {
  holding = -1;
}
​
function keyReleased() {
  if(key == 'e') export_data();
  else if(key == 'i') import_data();
  else if(key == 's') {
    sym = !sym;
    hover.timeout = 100;
    hover.text = "symmetry " + (sym ? "on" : "off");
  }
  else if(key == ' ') {
    for(let i=0; i<n_fourier; i++) fourier[i] = 0;
    pt = 0;
  }
}
​
function export_data() {
  data = JSON.stringify({points: points, fourier: fourier});
  prompt("exported data", data);
}
​
function import_data() {
  data = prompt("import data");
  try {
    data = JSON.parse(data);
    if(data.points) {
      points = data.points;
      n_points = data.points.length;
    }
    if(data.fourier) {
      fourier = data.fourier;
    }
  } catch(e) {
    alert("Data incorrectly formatted");
  }
}