Working with ScrollTrigger while in css zoom on body

[Tyco Interactive]

In our website we set zoom out on our body, calculated by js on every resize, so that we maintain the layout of our desktop (1920) on smaller resolutions (from 1200 up).

We then calculate the actual vw/vh by multiplying the clientWidth and clientHeight with the zoom factor.

The problem is that ScrollTrigger, of course, uses regular clientWidth/clientHeight and vw/vh and our method throws all of its calculations off.

I think that the solution would be using Gsap's scrollerProxy, but I did not succeed in that. What I would like is to override ScrollTriggers clientWidth and clientHeight with my calculated values.

 

Here is the actual code I use for setting the body zoom, so that my question is better understood:

 

<style>
    :root {
        --desktop-breakpoint: 1919.98px;
        --zoom-breakpoint: 1200.02px;
        --browser-zoom: 1;
        --browser-height: 100vh;
        --browser-width: 100vw;
    }

    @media (min-width: 1200.02px) and (max-width: 1919.98px) {
        body {
            zoom: var(--browser-zoom);
        }
    }
</style>

<script>
    function setZoom() {
        const doc = document.documentElement;

        // set the zoom value for matching laptop view to desktop
        let desktopBreakpoint = parseInt( getComputedStyle( document.documentElement ).getPropertyValue( '--desktop-breakpoint' ) ) ?? 1920;
        let zoomBreakpoint = parseInt( getComputedStyle( document.documentElement ).getPropertyValue( '--zoom-breakpoint' ) ) ?? 1200.02;
        doc.style.setProperty( '--browser-zoom', `${parseFloat(window.innerWidth / desktopBreakpoint).toFixed(2)}` );

        // set the css-variable value for --browser-height - take in account zoom out and add it to maintain actual 100vh
        // check if current window width is less than the zoom breakpoint, if so, set the zoom to 1
        let zoom = desktopBreakpoint / window.innerWidth;
        if ( window.innerWidth < zoomBreakpoint || zoom < 1 ) {
            doc.style.setProperty( '--browser-height', `${window.innerHeight}px` );
            doc.style.setProperty( '--browser-width', `${window.innerWidth}px` );
        } else {
            doc.style.setProperty( '--browser-height', `${window.innerHeight * zoom}px` );
            doc.style.setProperty( '--browser-width', `${window.innerWidth * zoom}px` );
        }
    }

    setZoom();
</script>

[GSAP Helper]

It's very difficult to troubleshoot without a minimal demo; the issue could be caused by CSS, markup, a third party library, your browser, an external script that's totally unrelated to GSAP, etc. Would you please provide a very simple CodePen or Stackblitz that illustrates the issue? 

 

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. 

[Tyco Interactive]

i have created a CodePen for my problem. my problem happening only in resolution between 1000 to 1920 when the zoom property is not equel to 1.

See the Pen GReovOm by Tyco-Interactive (@Tyco-Interactive) on CodePen

[GreenSock]

Are you trying to do this?: 

See the Pen poYyqRp?editors=0010 by GreenSock (@GreenSock) on CodePen

 

Just beware that the CSS property "zoom" is not officially part of the spec, so I wouldn't count on it working in every browser: 

https://developer.mozilla.org/en-US/docs/Web/CSS/zoom

[Tyco Interactive]

Yes, this is precisely what I needed. Thank you very much. 😁