vanilla-tilt.js

var VanillaTilt = (function () {
  'use strict';

  /**
   * Created by Sergiu Șandor (micku7zu) on 1/27/2017.
   * Original idea: https://github.com/gijsroge/tilt.js
   * MIT License.
   * Version 1.7.0
   */

  class VanillaTilt {
    constructor(element, settings = {}) {
      if (!(element instanceof Node)) {
        throw ("Can't initialize VanillaTilt because " + element + " is not a Node.");
      }

      this.width = null;
      this.height = null;
      this.clientWidth = null;
      this.clientHeight = null;
      this.left = null;
      this.top = null;

      // for Gyroscope sampling
      this.gammazero = null;
      this.betazero = null;
      this.lastgammazero = null;
      this.lastbetazero = null;

      this.transitionTimeout = null;
      this.updateCall = null;
      this.event = null;

      this.updateBind = this.update.bind(this);
      this.resetBind = this.reset.bind(this);

      this.element = element;
      this.settings = this.extendSettings(settings);

      this.reverse = this.settings.reverse ? -1 : 1;
      this.glare = VanillaTilt.isSettingTrue(this.settings.glare);
      this.glarePrerender = VanillaTilt.isSettingTrue(this.settings["glare-prerender"]);
      this.fullPageListening = VanillaTilt.isSettingTrue(this.settings["full-page-listening"]);
      this.gyroscope = VanillaTilt.isSettingTrue(this.settings.gyroscope);
      this.gyroscopeSamples = this.settings.gyroscopeSamples;

      this.elementListener = this.getElementListener();

      if (this.glare) {
        this.prepareGlare();
      }

      if (this.fullPageListening) {
        this.updateClientSize();
      }

      this.addEventListeners();
      this.updateInitialPosition();
    }

    static isSettingTrue(setting) {
      return setting === "" || setting === true || setting === 1;
    }

    /**
     * Method returns element what will be listen mouse events
     * @return {Node}
     */
    getElementListener() {
      if (this.fullPageListening) {
        return window.document;
      }

      if (typeof this.settings["mouse-event-element"] === "string") {
        const mouseEventElement = document.querySelector(this.settings["mouse-event-element"]);

        if (mouseEventElement) {
          return mouseEventElement;
        }
      }

      if (this.settings["mouse-event-element"] instanceof Node) {
        return this.settings["mouse-event-element"];
      }

      return this.element;
    }

    /**
     * Method set listen methods for this.elementListener
     * @return {Node}
     */
    addEventListeners() {
      this.onMouseEnterBind = this.onMouseEnter.bind(this);
      this.onMouseMoveBind = this.onMouseMove.bind(this);
      this.onMouseLeaveBind = this.onMouseLeave.bind(this);
      this.onWindowResizeBind = this.onWindowResize.bind(this);
      this.onDeviceOrientationBind = this.onDeviceOrientation.bind(this);

      this.elementListener.addEventListener("mouseenter", this.onMouseEnterBind);
      this.elementListener.addEventListener("mouseleave", this.onMouseLeaveBind);
      this.elementListener.addEventListener("mousemove", this.onMouseMoveBind);

      if (this.glare || this.fullPageListening) {
        window.addEventListener("resize", this.onWindowResizeBind);
      }

      if (this.gyroscope) {
        window.addEventListener("deviceorientation", this.onDeviceOrientationBind);
      }
    }

    /**
     * Method remove event listeners from current this.elementListener
     */
    removeEventListeners() {
      this.elementListener.removeEventListener("mouseenter", this.onMouseEnterBind);
      this.elementListener.removeEventListener("mouseleave", this.onMouseLeaveBind);
      this.elementListener.removeEventListener("mousemove", this.onMouseMoveBind);

      if (this.gyroscope) {
        window.removeEventListener("deviceorientation", this.onDeviceOrientationBind);
      }

      if (this.glare || this.fullPageListening) {
        window.removeEventListener("resize", this.onWindowResizeBind);
      }
    }

    destroy() {
      clearTimeout(this.transitionTimeout);
      if (this.updateCall !== null) {
        cancelAnimationFrame(this.updateCall);
      }

      this.reset();

      this.removeEventListeners();
      this.element.vanillaTilt = null;
      delete this.element.vanillaTilt;

      this.element = null;
    }

    onDeviceOrientation(event) {
      if (event.gamma === null || event.beta === null) {
        return;
      }

      this.updateElementPosition();

      if (this.gyroscopeSamples > 0) {
        this.lastgammazero = this.gammazero;
        this.lastbetazero = this.betazero;

        if (this.gammazero === null) {
          this.gammazero = event.gamma;
          this.betazero = event.beta;
        } else {
          this.gammazero = (event.gamma + this.lastgammazero) / 2;
          this.betazero = (event.beta + this.lastbetazero) / 2;
        }

        this.gyroscopeSamples -= 1;
      }

      const totalAngleX = this.settings.gyroscopeMaxAngleX - this.settings.gyroscopeMinAngleX;
      const totalAngleY = this.settings.gyroscopeMaxAngleY - this.settings.gyroscopeMinAngleY;

      const degreesPerPixelX = totalAngleX / this.width;
      const degreesPerPixelY = totalAngleY / this.height;

      const angleX = event.gamma - (this.settings.gyroscopeMinAngleX + this.gammazero);
      const angleY = event.beta - (this.settings.gyroscopeMinAngleY + this.betazero);

      const posX = angleX / degreesPerPixelX;
      const posY = angleY / degreesPerPixelY;

      if (this.updateCall !== null) {
        cancelAnimationFrame(this.updateCall);
      }

      this.event = {
        clientX: posX + this.left,
        clientY: posY + this.top,
      };

      this.updateCall = requestAnimationFrame(this.updateBind);
    }

    onMouseEnter() {
      this.updateElementPosition();
      this.element.style.willChange = "transform";
      this.setTransition();
    }

    onMouseMove(event) {
      if (this.updateCall !== null) {
        cancelAnimationFrame(this.updateCall);
      }

      this.event = event;
      this.updateCall = requestAnimationFrame(this.updateBind);
    }

    onMouseLeave() {
      this.setTransition();

      if (this.settings.reset) {
        requestAnimationFrame(this.resetBind);
      }
    }

    reset() {
      this.event = {
        clientX: this.left + this.width / 2,
        clientY: this.top + this.height / 2
      };

      if (this.element && this.element.style) {
        this.element.style.transform = `perspective(${this.settings.perspective}px) ` +
          `rotateX(0deg) ` +
          `rotateY(0deg) ` +
          `scale3d(1, 1, 1)`;
      }

      this.resetGlare();
    }

    resetGlare() {
      if (this.glare) {
        this.glareElement.style.transform = "rotate(180deg) translate(-50%, -50%)";
        this.glareElement.style.opacity = "0";
      }
    }

    updateInitialPosition() {
      if (this.settings.startX === 0 && this.settings.startY === 0) {
        return;
      }

      this.onMouseEnter();

      if (this.fullPageListening) {
        this.event = {
          clientX: (this.settings.startX + this.settings.max) / (2 * this.settings.max) * this.clientWidth,
          clientY: (this.settings.startY + this.settings.max) / (2 * this.settings.max) * this.clientHeight
        };
      } else {
        this.event = {
          clientX: this.left + ((this.settings.startX + this.settings.max) / (2 * this.settings.max) * this.width),
          clientY: this.top + ((this.settings.startY + this.settings.max) / (2 * this.settings.max) * this.height)
        };
      }


      let backupScale = this.settings.scale;
      this.settings.scale = 1;
      this.update();
      this.settings.scale = backupScale;
      this.resetGlare();
    }

    getValues() {
      let x, y;

      if (this.fullPageListening) {
        x = this.event.clientX / this.clientWidth;
        y = this.event.clientY / this.clientHeight;
      } else {
        x = (this.event.clientX - this.left) / this.width;
        y = (this.event.clientY - this.top) / this.height;
      }

      x = Math.min(Math.max(x, 0), 1);
      y = Math.min(Math.max(y, 0), 1);

      let tiltX = (this.reverse * (this.settings.max - x * this.settings.max * 2)).toFixed(2);
      let tiltY = (this.reverse * (y * this.settings.max * 2 - this.settings.max)).toFixed(2);
      let angle = Math.atan2(this.event.clientX - (this.left + this.width / 2), -(this.event.clientY - (this.top + this.height / 2))) * (180 / Math.PI);

      return {
        tiltX: tiltX,
        tiltY: tiltY,
        percentageX: x * 100,
        percentageY: y * 100,
        angle: angle
      };
    }

    updateElementPosition() {
      let rect = this.element.getBoundingClientRect();

      this.width = this.element.offsetWidth;
      this.height = this.element.offsetHeight;
      this.left = rect.left;
      this.top = rect.top;
    }

    update() {
      let values = this.getValues();

      this.element.style.transform = "perspective(" + this.settings.perspective + "px) " +
        "rotateX(" + (this.settings.axis === "x" ? 0 : values.tiltY) + "deg) " +
        "rotateY(" + (this.settings.axis === "y" ? 0 : values.tiltX) + "deg) " +
        "scale3d(" + this.settings.scale + ", " + this.settings.scale + ", " + this.settings.scale + ")";

      if (this.glare) {
        this.glareElement.style.transform = `rotate(${values.angle}deg) translate(-50%, -50%)`;
        this.glareElement.style.opacity = `${values.percentageY * this.settings["max-glare"] / 800}`;
      }

      this.element.dispatchEvent(new CustomEvent("tiltChange", {
        "detail": values
      }));

      this.updateCall = null;
    }

    /**
     * Appends the glare element (if glarePrerender equals false)
     * and sets the default style
     */
    prepareGlare() {
      // If option pre-render is enabled we assume all html/css is present for an optimal glare effect.
      if (!this.glarePrerender) {
        // Create glare element
        const jsTiltGlare = document.createElement("div");
        jsTiltGlare.classList.add("js-tilt-glare");

        const jsTiltGlareInner = document.createElement("div");
        jsTiltGlareInner.classList.add("js-tilt-glare-inner");

        jsTiltGlare.appendChild(jsTiltGlareInner);
        this.element.appendChild(jsTiltGlare);
      }

      this.glareElementWrapper = this.element.querySelector(".js-tilt-glare");
      this.glareElement = this.element.querySelector(".js-tilt-glare-inner");

      if (this.glarePrerender) {
        return;
      }

      Object.assign(this.glareElementWrapper.style, {
        "position": "absolute",
        "top": "0",
        "left": "0",
        "width": "100%",
        "height": "100%",
        "overflow": "hidden",
        "pointer-events": "none",
        "border-radius": "20px"
      });

      Object.assign(this.glareElement.style, {
        "position": "absolute",
        "top": "50%",
        "left": "50%",
        "pointer-events": "none",
        "background-image": `linear-gradient(0deg, rgba(255,255,255,0) 0%, rgba(255,255,255,1) 100%)`,
        "width": `${this.element.offsetWidth * 2}px`,
        "height": `${this.element.offsetWidth * 2}px`,
        "transform": "rotate(180deg) translate(-50%, -50%)",
        "transform-origin": "0% 0%",
        "opacity": "0",
      });
    }

    updateGlareSize() {
      if (this.glare) {
        Object.assign(this.glareElement.style, {
          "width": `${this.element.offsetWidth * 2}`,
          "height": `${this.element.offsetWidth * 2}`,
        });
      }
    }

    updateClientSize() {
      this.clientWidth = window.innerWidth
        || document.documentElement.clientWidth
        || document.body.clientWidth;

      this.clientHeight = window.innerHeight
        || document.documentElement.clientHeight
        || document.body.clientHeight;
    }

    onWindowResize() {
      this.updateGlareSize();
      this.updateClientSize();
    }

    setTransition() {
      clearTimeout(this.transitionTimeout);
      this.element.style.transition = this.settings.speed + "ms " + this.settings.easing;
      if (this.glare) this.glareElement.style.transition = `opacity ${this.settings.speed}ms ${this.settings.easing}`;

      this.transitionTimeout = setTimeout(() => {
        this.element.style.transition = "";
        if (this.glare) {
          this.glareElement.style.transition = "";
        }
      }, this.settings.speed);

    }

    /**
     * Method return patched settings of instance
     * @param {boolean} settings.reverse - reverse the tilt direction
     * @param {number} settings.max - max tilt rotation (degrees)
     * @param {startX} settings.startX - the starting tilt on the X axis, in degrees. Default: 0
     * @param {startY} settings.startY - the starting tilt on the Y axis, in degrees. Default: 0
     * @param {number} settings.perspective - Transform perspective, the lower the more extreme the tilt gets
     * @param {string} settings.easing - Easing on enter/exit
     * @param {number} settings.scale - 2 = 200%, 1.5 = 150%, etc..
     * @param {number} settings.speed - Speed of the enter/exit transition
     * @param {boolean} settings.transition - Set a transition on enter/exit
     * @param {string|null} settings.axis - What axis should be disabled. Can be X or Y
     * @param {boolean} settings.glare - What axis should be disabled. Can be X or Y
     * @param {number} settings.max-glare - the maximum "glare" opacity (1 = 100%, 0.5 = 50%)
     * @param {boolean} settings.glare-prerender - false = VanillaTilt creates the glare elements for you, otherwise
     * @param {boolean} settings.full-page-listening - If true, parallax effect will listen to mouse move events on the whole document, not only the selected element
     * @param {string|object} settings.mouse-event-element - String selector or link to HTML-element what will be listen mouse events
     * @param {boolean} settings.reset - false = If the tilt effect has to be reset on exit
     * @param {gyroscope} settings.gyroscope - Enable tilting by deviceorientation events
     * @param {gyroscopeSensitivity} settings.gyroscopeSensitivity - Between 0 and 1 - The angle at which max tilt position is reached. 1 = 90deg, 0.5 = 45deg, etc..
     * @param {gyroscopeSamples} settings.gyroscopeSamples - How many gyroscope moves to decide the starting position.
     */
    extendSettings(settings) {
      let defaultSettings = {
        reverse: false,
        max: 15,
        startX: 0,
        startY: 0,
        perspective: 1000,
        easing: "cubic-bezier(.03,.98,.52,.99)",
        scale: 1,
        speed: 300,
        transition: true,
        axis: null,
        glare: false,
        "max-glare": 1,
        "glare-prerender": false,
        "full-page-listening": false,
        "mouse-event-element": null,
        reset: true,
        gyroscope: true,
        gyroscopeMinAngleX: -45,
        gyroscopeMaxAngleX: 45,
        gyroscopeMinAngleY: -45,
        gyroscopeMaxAngleY: 45,
        gyroscopeSamples: 10
      };

      let newSettings = {};
      for (var property in defaultSettings) {
        if (property in settings) {
          newSettings[property] = settings[property];
        } else if (this.element.hasAttribute("data-tilt-" + property)) {
          let attribute = this.element.getAttribute("data-tilt-" + property);
          try {
            newSettings[property] = JSON.parse(attribute);
          } catch (e) {
            newSettings[property] = attribute;
          }

        } else {
          newSettings[property] = defaultSettings[property];
        }
      }

      return newSettings;
    }

    static init(elements, settings) {
      if (elements instanceof Node) {
        elements = [elements];
      }

      if (elements instanceof NodeList) {
        elements = [].slice.call(elements);
      }

      if (!(elements instanceof Array)) {
        return;
      }

      elements.forEach((element) => {
        if (!("vanillaTilt" in element)) {
          element.vanillaTilt = new VanillaTilt(element, settings);
        }
      });
    }
  }

  if (typeof document !== "undefined") {
    /* expose the class to window */
    window.VanillaTilt = VanillaTilt;

    /**
     * Auto load
     */
    VanillaTilt.init(document.querySelectorAll("[data-tilt]"));
  }

  return VanillaTilt;

}());