Navigation links not ending up on exact location of section when horizontal scrolling is used

[Cessy]

I've implemented a horizontal scrolling feature using GSAP. However, when I click on a link in the nav, it does not link me to the exact location of each section.

Here's the website I've made: https://southfield-center.webflow.io/

 

Here's the GSAP code I used:

 

<script src="https://unpkg.co/gsap@3/dist/gsap.min.js"></script>
<script src="https://unpkg.com/gsap@3/dist/ScrollTrigger.min.js"></script>
<script src="https://unpkg.com/gsap@3/dist/ScrollToPlugin.min.js"></script>

<script>
  gsap.registerPlugin(ScrollTrigger);

  function getScrollLookup(targets, { start, pinnedContainer, containerAnimation }) {
    let triggers = gsap.utils.toArray(targets).map((el) =>
      ScrollTrigger.create({
        trigger: el,
        start: start || "top top",
        pinnedContainer: pinnedContainer,
        refreshPriority: -10,
        containerAnimation: containerAnimation,
      })
    );
    return (target) => {
      let t = gsap.utils.toArray(target)[0];
      let i = triggers.length;
      while (i-- && triggers[i].trigger !== t) {}
      if (i < 0) {
        return console.warn("target not found", target);
      }
      return containerAnimation
        ? st.start + (triggers[i].start / containerAnimation.duration()) * (st.end - st.start)
        : triggers[i].start;
    };
  }

  // Function to initialize the scroll animation
  function initScrollAnimation() {
    let sections = gsap.utils.toArray(".section"),
      navLinks = document.querySelectorAll(".gsap-code"),
      nav = document.querySelectorAll(".nav"),
      getMaxWidth = () => {
        let width = 0;
        sections.forEach((section) => {
          const rect = section.getBoundingClientRect();
          width += rect.width;
          console.log(`Section ${section.id} width: ${rect.width}`);
        });
        return width;
      },
      maxWidth = getMaxWidth(),
      scrollSpeed = 16,
      snapProgress,
      lastScrollTween = Date.now(),
      curIndex = 0,
      tl = gsap.timeline();

    tl.to(sections, {
      x: () => window.innerWidth - maxWidth,
      duration: 1,
      ease: "none",
    });

    ScrollTrigger.create({
      animation: tl,
      trigger: ".scrollable-div",
      pin: true,
      scrub: 1,
      invalidateOnRefresh: true,
    });

    function init() {
      gsap.set(sections, { x: 0 });
      maxWidth = getMaxWidth();
      let position = 0,
        distance = maxWidth - window.innerWidth;
      tl.add("label0", 0);
      sections.forEach((section, i) => {
        let progress = position;
        const rect = section.getBoundingClientRect();
        position += rect.width / distance;
        tl.add("label" + (i + 1), position);

        if (i < navLinks.length) {
          navLinks[i].onclick = () => {
            snapProgress = progress;
            lastScrollTween = Date.now();
            curIndex = i;
            gsap.to(window, { scrollTo: maxWidth / scrollSpeed * progress, duration: 1, overwrite: "auto" });
          };
        }
      });
    }

    init();
    ScrollTrigger.addEventListener("refreshInit", init);

    ScrollTrigger.create({
      trigger: ".section_about",
      start: "top top",
      onToggle: (self) => {
        if (self.isActive) {
          gsap.set(nav, { display: "flex" });
        } else {
          gsap.set(nav, { display: "none" });
        }
      },
    });

    let getPosition = getScrollLookup(".section", {
      start: "center center",
      containerAnimation: tl,
    });

    navLinks.forEach((link) => {
      link.onclick = (e) => {
        e.preventDefault();
        let target = e.target.getAttribute("href");
        gsap.to(window, { scrollTo: getPosition(target), duration: 1, overwrite: "auto" });
      };
    });
  }

  if (window.innerWidth >= 992) {
    initScrollAnimation();
  }
</script>

 

[GSAP Helper]

Unfortunately, we can't really troubleshoot a live site like that. If you'd like help, please make sure you provide a minimal demo like a CodePen or Stackblitz

 

Please don't include your whole project. Just some colored <div> elements and the GSAP code is best. See if you can recreate the issue with as few dependancies as possible. If not, incrementally add code bit by bit until it breaks. Usually people solve their own issues during this process! If not, then at least we have a reduced test case which greatly increases your chances of getting a relevant answer.

 

Here's a starter CodePen that loads all the plugins. Just click "fork" at the bottom right and make your minimal demo: 

See the Pen aYYOdN by GreenSock (@GreenSock) on CodePen

 

Using a framework/library like React, Vue, Next, etc.? 

CodePen isn't always ideal for these tools, so here are some Stackblitz starter templates that you can fork and import the gsap-trial NPM package for using any of the bonus plugins: 

• React (please read this article!)
• Next
• Svelte
• Sveltekit
• Vue
• Nuxt

 

Please share the StackBlitz link directly to the file in question (where you've put the GSAP code) so we don't need to hunt through all the files. 

 

Once we see an isolated demo, we'll do our best to jump in and help with your GSAP-specific questions.