Function levelProgress

packages/webapp/components/world/ladder.ts:161–183

(reads: number, div = 1)

 * to rank on `toNext`.
 */
export const levelProgress = (reads: number, div = 1): LevelProgress => {
  const level = div === 1 ? levelOf(reads) : realmLevelOf(reads);
  if (level >= MAX_LEVEL) {
    return { level, toNext: 0, fraction: 1 };
  }

  const ceiling = LEVELS[level].reads * div;
  /* `realmLevelOf` floors at L1, so a realm sitting on its first rung can hold
     fewer articles than that rung's own threshold. Clamping the floor to what
     has actually been read keeps such a realm at the START of the bar instead
     of behind it. A district cannot reach L1 below the threshold, so this is
     the identity for everything else. */
  const floor = Math.min(floorOf(level) * div, reads);

  return {
    level,
    /* Ceiled: the ladder is walked in whole articles, and a realm 0.4 of an
       article short still needs one more read to cross. */
    toNext: Math.ceil(ceiling - reads),
    fraction: (reads - floor) / (ceiling - floor),
    next: LEVELS[level],
  };
};

/** The least a district has to carry to be worth pointing at. */
export interface LadderRow {