let charges = new Map();
let counter = 0;

let sphere_mode = 'circles';
let sphere_radius = 200;

function preload() {
  earth = loadImage("atlas1.jpg");
}

function setup() {
  createCanvas(600, 600, WEBGL);
}

function draw() {
  orbitControl();
  background(50);

  make_lights();
  draw_sphere(sphere_radius, 25);
}

function draw_sphere(radius, n_axis_circles) {
  stroke(0x3f);
  noFill();

  push();
  rotateX(TAU / 4);
  draw_circles(
    radius,
    sphere_mode === 'earth' ? 2 : n_axis_circles,
    color(0x00, 0x9f, 0xff),
    color(0xff, 0x9f, 0x00),
  );
  pop();
  push();
  rotateY(TAU / 4);
  draw_circles(
    radius,
    sphere_mode === 'earth' ? 2 : n_axis_circles,
    color(0xff, 0x00, 0xff),
    color(0x00, 0xff, 0x00),
  );
  pop();

  if (sphere_mode === 'earth') {
    noStroke();
    noFill();
    tint(0xff, 0x9f);
    texture(earth);
    push();
    rotateY(TAU / 4);
    sphere(radius);
    pop();
  }
}

function draw_circles(radius, n_circles, pole_1_color, pole_2_color) {
  push();
  stroke(pole_1_color);
  translate(0, 0, -radius);
  point(0, 0);
  pop();
  for (let i = 1; i < n_circles; i += 1) {
    const angle = map(i, 0, n_circles - 1, -TAU / 4, TAU / 4);
    const circle_radius = radius * cos(angle);
    push();
    translate(0, 0, radius * sin(angle));
    circle(0, 0, circle_radius * 2);
    pop();
  }
  push();
  stroke(pole_2_color);
  translate(0, 0, radius);
  point(0, 0);
  pop();
}

function make_lights() {
  let light = createVector(0, 1, -1);
  light.normalize();
  directionalLight(0x1f, 0x1f, 0x1f, light);
  ambientLight(0xbf);
}

function keyPressed() {
  if (key == 'd') {
    sphere_mode = sphere_mode === 'earth' ? 'circles' : 'earth';
  }
}