/*https://editor.p5js.org/p5/sketches/Math:_Randomchords
 * @name Random Chords
 * @description Accumulates random chords of a circle. Each chord in translucent
 * so they accumulate to give the illusion of a shaded sphere.
 * Contributed by Aatish Bhatia, inspired by <a href ="http://inconvergent.net/">Anders Hoff</a>
 */

function setup() {
  createCanvas(400, 400);
  background(255, 255, 255);

  // translucent stroke using alpha value
  stroke(0, 0, 0, 15);
}

function draw() {
  // draw two random chords each frame
  randomChord();
  randomChord();
}

function randomChord() {
  // find a random point on a circle
  let angle1 = random(0, 2 * PI);
  let xpos1 = 200 + 200 * cos(angle1);
  let ypos1 = 200 + 200 * sin(angle1);

  // find another random point on the circle
  let angle2 = random(0, 2 * PI);
  let xpos2 = 200 + 200 * cos(angle2);
  let ypos2 = 200 + 200 * sin(angle2);

  // draw a line between them
  line(xpos1, ypos1, xpos2, ypos2);
}