up/docs/javascripts/extra.js

/**
 * Godspark Refined — Zensical Light JS
 *  - Scroll reveal for `.gp-reveal`
 *  - Cursor glow via `[gp-glow]` attribute
 *  - Reduced-motion safe
 */
;(function () {
  "use strict";

  const prefersReducedMotion = window.matchMedia(
    "(prefers-reduced-motion: reduce)"
  ).matches;

  function initScrollReveal() {
    if (prefersReducedMotion) return;

    const nodes = document.querySelectorAll(".gp-reveal");
    if (!nodes.length) return;

    const thresholdRaw = getComputedStyle(document.documentElement)
      .getPropertyValue("--gp-reveal-threshold")
      .trim();

    const threshold = Number.isFinite(parseFloat(thresholdRaw))
      ? parseFloat(thresholdRaw)
      : 0.12;

    const observer = new IntersectionObserver(
      (entries) => {
        entries.forEach((entry) => {
          if (entry.isIntersecting) {
            entry.target.classList.add("is-visible");
            observer.unobserve(entry.target);
          }
        });
      },
      { threshold, rootMargin: "0px 0px -16px 0px" }
    );

    nodes.forEach((el) => observer.observe(el));
  }

  function initCursorGlow() {
    const el = document.documentElement;
    const enabled =
      el.hasAttribute("gp-glow") || el.classList.contains("gp-glow-active");

    if (!enabled) return;
    if (prefersReducedMotion) return;

    el.classList.add("gp-glow-active");

    let raf = false;
    function setGlow(x, y) {
      el.style.setProperty("--gp-cursor-x", x + "px");
      el.style.setProperty("--gp-cursor-y", y + "px");
    }

    function onMove(e) {
      if (raf) return;
      raf = true;
      requestAnimationFrame(() => {
        const cx = e.touches ? e.touches[0].clientX : e.clientX;
        const cy = e.touches ? e.touches[0].clientY : e.clientY;
        setGlow(cx, cy);
        raf = false;
      });
    }

    function onHide() { el.style.setProperty("--gp-glow-opacity", "0"); }
    function onShow() { el.style.setProperty("--gp-glow-opacity", "1"); }

    const passive = { passive: true };
    document.addEventListener("mousemove", onMove, passive);
    document.addEventListener("touchmove", onMove, passive);
    document.addEventListener("mouseleave", onHide);
    document.addEventListener("mouseenter", onShow);
  }

  function boot() {
    initScrollReveal();
    initCursorGlow();
    initCusdisReload();
  }

  /**
   * Re-initialize Cusdis comment widget after Zensical instant-navigation
   * page transitions (XHR-based SPA navigation). Without this, the widget
   * only renders on hard-refresh / initial page load.
   */
  function initCusdisReload() {
    if (typeof document$ === "undefined") return; // not in Zensical context

    document$.subscribe(function () {
      var el = document.getElementById("cusdis_thread");
      if (!el) return;

      // Clear stale Cusdis iframe from previous page render
      el.innerHTML = "";

      // Re-create Cusdis widget for the new page
      if (window.CUSDIS && typeof window.CUSDIS.renderTo === "function") {
        window.CUSDIS.renderTo(el);
      }
    });
  }

  if (document.readyState === "loading") {
    document.addEventListener("DOMContentLoaded", boot);
  } else {
    boot();
  }
})();