utils.js

import { globals } from './globals.js';
import { state } from './state.js';

const uuid = () => {
  let dt = new Date().getTime();
  const u = 'xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx'.replace(/[xy]/g, (c) => {
    const r = (dt + Math.random() * 16) % 16 | 0;
    dt = Math.floor(dt / 16);
    return (c === 'x' ? r : (r & 0x3) | 0x8).toString(16);
  });
  return u;
};

const generateColours = (n) => {
  const s = chroma.scale('Spectral');
  return s.colors(n);
};

const generateRandomColour = () => {
  // Get a list of the currently used colours (including the background)
  const colours = state.species.map((s) => s.colour);
  colours.push(chroma('#000000'));

  // Find the average contrast between all colours
  const average = (newColour) =>
    colours.reduce((p, c) => p + chroma.contrast(c, newColour), 0) /
    colours.length;

  let randomColour = chroma.random();
  // Keep generating colours until it's above threshold
  while (average(randomColour) < 7) {
    randomColour = chroma.random();
  }
  return randomColour;
};

const colourCritters = (critters, colour) => {
  critters.forEach((c) => {
    const cc = new Path2D();
    cc.arc(c.position.x, c.position.y, globals.collisionRadius, 0, 2 * Math.PI);
    globals.ctx.fillStyle = colour;
    globals.ctx.fill(cc);
  });
};

const directionTowardsCritter = (c1, c2) =>
  Math.atan((c2.position.y - c1.position.y) / (c2.position.x - c1.position.x));

const distanceBetweenCritters = (c1, c2) =>
  Math.sqrt(
    (c1.position.x - c2.position.x) ** 2 + (c1.position.y - c2.position.y) ** 2,
  );

const degreesToRads = (degrees) => 2 * Math.PI * (degrees / 360);

const clearCanvas = () => {
  globals.ctx.clearRect(0, 0, globals.canvasWidth, globals.canvasHeight);
};

export {
  colourCritters,
  degreesToRads,
  clearCanvas,
  generateRandomColour,
  distanceBetweenCritters,
  directionTowardsCritter,
  generateColours,
  uuid,
};