Image Trail Animation for an Intro

import { gsap } from 'gsap';

/**
 * Class representing a fake progress loader
 */
export class FakeProgress {
	// DOM elements
	DOM = {
		// Main element
		el: null,
	};
	progressVal = {value: 0};

	/**
	 * Constructor.
	 * @param {Element} DOM_el
	 */
	constructor(DOM_el) {
		this.DOM.el = DOM_el;
	}
	/**
	 * Simulates a loading progress.
	 * @param {Function} onProgressComplete callback
	 * @return {GSAP Timeline}
	 */
	onComplete(onProgressComplete) {
		return gsap.timeline().to(this.progressVal, {
			duration: 1.5,
			ease: 'steps(14)',
			value: 100,
			onUpdate: () => this.DOM.el.innerHTML = Math.floor(this.progressVal.value) + '%',
			onComplete: onProgressComplete
		})
		// then hide it
		.to(this.DOM.el, {
			duration: 0.7,
			ease: 'power3.inOut',
			opacity: 0
		});
	}
}

export const animationDefaults = {
    duration: 1.4,
    ease: 'power4'
};

import { preloadImages } from './utils'
import { TrailImage, TrailText } from './trail';
import { FakeProgress } from './fakeProgress';
import { TextLinesReveal } from './textLinesReveal';
import { animationDefaults } from './gsapAnimation';
import { gsap } from 'gsap';
import { Flip } from 'gsap/Flip';
gsap.registerPlugin(Flip);

// trail elements (Image and the two intro title elements (up and down)
const trailImage = new TrailImage(document.querySelector('.intro-image'), {perspective: 1000, totalTrailElements: 8});
const trailTextTop = new TrailText(document.querySelector('.intro-content__title--up'), {perspective: 1000, totalTrailElements: 2});
const trailTextBottom = new TrailText(document.querySelector('.intro-content__title--down'), {totalTrailElements: 3});

// DOM elements
const frame = {
	menu: document.querySelector('.button-menu'),
	logo: document.querySelector('.logo'),
	progress: document.querySelector('.intro-progress')
};
const intro = {
	image: document.querySelector('.intro-content__image'),
	enterButton: document.querySelector('.button-enter'),
};
const content = {
	titleTop: document.querySelector('.content__title--up'),
	titleBottom: document.querySelector('.content__title--down'),
	about: document.querySelector('.content__about'),
	aboutText: document.querySelector('.content__about-text'),
	finalImagePlacement: document.querySelector('.content__image--2'),
	otherImages: document.querySelectorAll('.content__image--1 > .content__image-inner, .content__image--3 > .content__image-inner')
}

// the TextLinesReveal instance (animate each text line of the about text using the SplitText library)
const aboutLines = new TextLinesReveal(content.aboutText);

// state
let state = {
	isAnimating: false,
	iscontentOpen: false
};

// First step: fake progress and move the image to the center of the screen. Also animate the top/bottom texts in and show the enter button
const showIntro = () => {
	
	if ( state.isAnimating ) {
		return false;
	}
	state.isAnimating = true;

	gsap.timeline({
		defaults: animationDefaults,
		onComplete: () => {
			// Reset the trails structure on the texts and image
			trailTextTop.reset();
			trailTextBottom.reset();
			trailImage.reset();

			state.isAnimating = false;
		}
	})
	.addLabel('start', 0)
	.add(() => {
		// Let's use the gsap Flip plugin to animate the image into a new element (.intro-content__image)
		// Get state
		const state = Flip.getState(trailImage.DOM.trailElems);
		// Change place
		intro.image.appendChild(trailImage.DOM.el);
		// Flip
		Flip.from(state, {
			duration: animationDefaults.duration,
			ease: animationDefaults.ease,
			stagger: -0.03,
			scale: true
			//rotateY: 360,
		})
	}, 'start') 
	// Hide the intro title trail elements initially and show its parents which are hidden by default (CSS)
	.set([trailTextTop.DOM.trailElems, trailTextBottom.DOM.trailElems], {
		opacity: 0
	}, 'start')
	.set([trailTextTop.DOM.el, trailTextBottom.DOM.el], {
		opacity: 1
	}, 'start')
	// Now translate the title elements
	.to(trailTextTop.DOM.trailElems, {
		y: 0,
		startAt: {rotateY: 160, opacity: 0},
		rotateY: 0,
		opacity: 1,
		stagger: -0.1
	}, 'start')
	.to(trailTextBottom.DOM.trailElems, {
		y: 0,
		opacity: 1,
		stagger: -0.08,
	}, 'start')
	// And show the intro enter button
	.to(intro.enterButton, {
		startAt: {opacity: 0, scale: 0.8},
		opacity: 1,
		scale: 1
	}, 'start+=0.3')
	.add(() => {
		// Show the logo and menu button 
		frame.menu.classList.add('show');
		frame.logo.classList.add('show');
	}, 'start+=0.3');
	
};

// Second step: show the other images and scale down the texts
const showContent = () => {
	
	if ( state.isAnimating || state.iscontentOpen ) {
		return false;
	}
	state.isAnimating = true;
	state.iscontentOpen = true;

	gsap.timeline({
		defaults: animationDefaults,
		onComplete: () => {
			state.isAnimating = false;
		}
	})
	.addLabel('start', 0)
	.to(intro.enterButton, {
		duration: 0.6,
		opacity: 0, 
		scale: 0.8,
	}, 'start')
	.add(() => {

		const topTitleState = Flip.getState(trailTextTop.DOM.el);
		const bottomTitleState = Flip.getState(trailTextBottom.DOM.el);
		
		content.titleTop.appendChild(trailTextTop.DOM.el);
		content.titleBottom.appendChild(trailTextBottom.DOM.el);
		
		Flip.from(topTitleState, {
			duration: animationDefaults.duration,
			ease: animationDefaults.ease,
			scale: true
		});
		
		Flip.from(bottomTitleState, {
			duration: animationDefaults.duration,
			ease: animationDefaults.ease,
			scale: true
		});
		
		const imageState = Flip.getState(trailImage.DOM.el, {props: 'border-radius'});
		// Change place
		content.finalImagePlacement.appendChild(trailImage.DOM.el);
		gsap.set(trailImage.DOM.el, {opacity: 1});
		// Flip
		Flip.from(imageState, {
			duration: animationDefaults.duration,
			ease: animationDefaults.ease
		});
		
	}, 'start')
	
	// animate the other images in
	.to(content.otherImages, {
		startAt: {yPercent: 100},
		yPercent: 0,
		opacity: 1
	}, 'start+=0.1')
	// about section
	.to(content.about, {
		startAt: {yPercent: 10},
		yPercent: 0,
		opacity: 1
	}, 'start+=0.2')
	// about text lines
	.add( () => {
		aboutLines.in();
	}, 'start+=0.2')

};

// Enter button click event
intro.enterButton.addEventListener('click', showContent);

// Simulate the initial progress
const fakeProgress = new FakeProgress(frame.progress);
fakeProgress.onComplete(showIntro);

// Preload images
preloadImages('.intro-image').then( _ => document.body.classList.remove('loading'));

import SplitType from 'split-type';
import { animationDefaults } from './gsapAnimation';
import { wrapLines } from './utils';
import { gsap } from 'gsap';

/**
 * Class representing a text line element that reveals itself by animating its translateY value
 */
export class TextLinesReveal {
    // DOM elements
    DOM = {
        // main element (a text DOM element)
        el: null
    }
    // Split Type instance
    SplitTypeInstance;
    // Checks if the Split Type lines are visible or not
    isVisible;
    // Animation timelines
    inTimeline;
    outTimeline;

    /**
     * Constructor.
     * @param {Element} DOM_el - a text DOM element
     */
    constructor(DOM_el) {
        this.DOM = {
            el: DOM_el
        };

        this.SplitTypeInstance = new SplitType(this.DOM.el, { types: 'lines' });
        // Wrap the lines (div with class .oh)
        // The inner child will be the one animating the transform
        wrapLines(this.SplitTypeInstance.lines, 'div', 'oh');
        
        this.initEvents();
    }

    /**
     * Animates the lines in.
     * @return {GSAP Timeline} the animation timeline
     * @param {Boolean} animation - with or without animation.
     */
    in(animation = true) {
        // Lines are visible
        this.isVisible = true;

        gsap.killTweensOf(this.SplitTypeInstance.lines);
        this.inTimeline = gsap.timeline({defaults: animationDefaults})
        .addLabel('start', 0)
        .set(this.SplitTypeInstance.lines, {
            yPercent: 105
        }, 'start');
        
        if ( animation ) {
            this.inTimeline.to(this.SplitTypeInstance.lines, {
                yPercent: 0,
                stagger: 0.04
            }, 'start');
        }
        else {
            this.inTimeline.set(this.SplitTypeInstance.lines, {
                yPercent: 0
            }, 'start');
        }
        
        return this.inTimeline;
    }

    /**
     * Animates the lines out.
     * @param {Boolean} animation - with or without animation.
     * @return {GSAP Timeline} the animation timeline
     */
    out(animation = true) {
        // Lines are invisible
        this.isVisible = false;

        gsap.killTweensOf(this.SplitTypeInstance.lines);
        
        this.outTimeline = gsap.timeline({defaults: animationDefaults}).addLabel('start', 0);
        
        if ( animation ) {
            this.outTimeline.to(this.SplitTypeInstance.lines, {
                yPercent: -105,
                stagger: 0.04
            }, 'start');
        }
        else {
            this.outTimeline.set(this.SplitTypeInstance.lines, {
                yPercent: -105,
            }, 'start');
        }

        return this.outTimeline;
    }

    /**
     * Initializes some events.
     */
    initEvents() {
        // Re-initialize the Split Text on window resize.
        window.addEventListener('resize', () => {
            // Re-split text
            // https://github.com/lukePeavey/SplitType#instancesplitoptions-void
            this.SplitTypeInstance.split();

            // Need to wrap again the new lines elements (div with class .oh)
            wrapLines(this.SplitTypeInstance.lines, 'div', 'oh');
                
            // Hide the lines
            if ( !this.isVisible ) {
                gsap.set(this.SplitTypeInstance.lines, {yPercent: 105});
            }
        });
    }
}

/**
 * Class representing a Trail element, 
 * an element that has [trailElems] children/clones (of type image or text) 
 * and that we can use to stagger it's translation so it looks like a trail or dragging effect 
 */
class Trail {
	// DOM elements
	DOM = {
		// Main element (.trail)
		el: null,
		// Trail child elements (.trail__img or .trail__text)
		trailElems: null,
	};
	// option defaults
	defaults = {
		// 3d
		perspective: false,
		// Total number of inner image elements
		totalTrailElements: 4,
	};

	/**
	 * Constructor.
	 * @param {Element} DOM_el - the .trail element
	 */
	constructor(DOM_el, options) {
		this.DOM.el = DOM_el;
		this.options = Object.assign(this.defaults, options);

		// 3d
		if ( this.options.perspective ) {
			this.DOM.el.style.perspective = `${this.options.perspective}px`
		}
	}
}

/**
 * Class representing an image trail element
 */
export class TrailImage extends Trail {
	// the image path
	bgImage;

	/**
	 * Constructor.
	 * @param {Element} DOM_el - the .trail element
	 */
	constructor(DOM_el, options) {
		super(DOM_el, options);
		// Get the main element's background image url 
		this.bgImage = /(?:\(['"]?)(.*?)(?:['"]?\))/.exec(this.DOM.el.style.backgroundImage)[1];
		// Create the HTML markup for the trail elements
		this.layout();
	}
	/**
	 * Creates the HTML markup for the trail elements
	 */
	layout() {
		// Remove the background image from the main element
		this.DOM.el.style.backgroundImage = 'none';

		let innerHTML = '';
		for (let i = 0; i <= this.options.totalTrailElements - 1; ++i) {
			const opacityVal = i === this.options.totalTrailElements - 1 ? 1 : 0.8;//1/this.options.totalTrailElements * i + 1/this.options.totalTrailElements
			innerHTML += `<img class="trail__img" src="${this.bgImage}" style="opacity: ${opacityVal}"/>`;
		}
		// Append to the main element
		this.DOM.el.innerHTML = innerHTML;

		// Get inner .trail__img elements
		this.DOM.trailElems = this.DOM.el.querySelectorAll('.trail__img');

		this.DOM.el.classList.add('trail');
	}
	reset() {
		this.DOM.el.classList.remove('trail');
		this.DOM.el.style.backgroundImage = `url(${this.bgImage})`;
		this.DOM.el.innerHTML = '';
		if ( this.options.perspective ) {
			this.DOM.el.style.perspective = 'none';
		}
	}
}

/**
 * Class representing a text trail element
 */
export class TrailText extends Trail {
	/**
	 * Constructor.
	 * @param {Element} DOM_el - the .trail element
	 */
	constructor(DOM_el, options) {
		super(DOM_el, options);
		// Create the HTML markup for the trail elements
		this.layout();
	}
	/**
	 * Creates the HTML markup for the trail elements
	 */
	layout() {
		// Get the main element's innerHTML
		this.content = this.DOM.el.innerHTML;

		let innerHTML = '';
		for (let i = 0; i <= this.options.totalTrailElements - 1; ++i) {
			const opacityVal = i === this.options.totalTrailElements - 1 ? 1 : 1/this.options.totalTrailElements * i + 1/this.options.totalTrailElements
			innerHTML += `<span class="trail__text" style="opacity: ${opacityVal}">${this.content}</span>`;
		}
		// Append to the main element
		this.DOM.el.innerHTML = innerHTML;

		// Get inner .trail__text elements
		this.DOM.trailElems = this.DOM.el.querySelectorAll('.trail__text');

		this.DOM.el.classList.add('trail');
	}
	reset() {
		this.DOM.el.classList.remove('trail');
		this.DOM.el.innerHTML = this.content;
		if ( this.options.perspective ) {
			this.DOM.el.style.perspective = 'none';
		}
	}
}

const imagesLoaded = require('imagesloaded');

/**
 * Preload images
 * @param {String} selector - Selector/scope from where images need to be preloaded. Default is 'img'
 */
const preloadImages = (selector = 'img') => {
    return new Promise((resolve) => {
        imagesLoaded(document.querySelectorAll(selector), {background: true}, resolve);
    });
};

/**
 * Wraps the elements of an array.
 * @param {Array} arr - the array of elements to be wrapped
 * @param {String} wrapType - the type of the wrap element ('div', 'span' etc)
 * @param {String} wrapClass - the wrap class(es)
 */
const wrapLines = (arr, wrapType, wrapClass) => {
    arr.forEach(el => {
        const wrapEl = document.createElement(wrapType);
        wrapEl.classList = wrapClass;
        el.parentNode.appendChild(wrapEl);
        wrapEl.appendChild(el);
    });
}

export {
    preloadImages,
    wrapLines
};

README.md
## Credits

- Images from [Unsplash](https://unsplash.com/)


## License
[MIT](LICENSE)

Made with :blue_heart:  by [Codrops](http://www.codrops.com)

MIT License

Copyright (c) 2009 - 2021 [Codrops](https://tympanus.net/codrops)

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.

GSAP standard license snapshot
Source: https://gsap.com/community/standard-license/
Retrieved: 2026-09-22T04:22:49.089Z
Original distribution copyright and version headers remain in the runtime code.

Standard "No Charge" GSAP License

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 “GSAP License” means the terms and conditions of this GSAP Software License Agreement.

 "GSAP Products" means any Software made available at gsap.com (https://gsap.com) or any successor sites, including but not limited to the GSAP animation library and related plugins, tools, or extensions.

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 FAQ

 Is it acceptable for AI tools like ChatGPT, Cursor, Lovable, Webstudio, etc. to generate GSAP code?
 Absolutely! AI-generated code is not a "Prohibited Use".

 What if a WordPress plugin or theme or other niche tool allows users to create GSAP-driven effects through a visual interface? Is that prohibited?
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 Yes, really! Commercial usage is covered under the standard license. All of GSAP including the plugins that were formerly "members-only" like SplitText (https://gsap.com/docs/v3/Plugins/SplitText/) and MorphSVG (https://gsap.com/docs/v3/Plugins/MorphSVGPlugin) can be used in commercial projects at no charge. Enjoy! 💚

 Effective date: April 30, 2025

 Last modified date: May 30, 2025

 Copyright (©) 2025, Webflow


ev-emitter@2.1.2 — LICENSE.md
Copyright (c) 2016-2021 [David DeSandro](https://desandro.com)

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.


imagesloaded@5.0.0 — LICENSE.md
Copyright (c) 2011-2022 [David DeSandro](https://desandro.com) and [contributors](https://github.com/desandro/imagesloaded/graphs/contributors)

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.