Snow Effect

Add a snow effect to any website

You will need to install an extension such as Tampermonkey, Greasemonkey or Violentmonkey to install this script.

You will need to install an extension such as Tampermonkey or Violentmonkey to install this script.

You will need to install an extension such as Tampermonkey or Violentmonkey to install this script.

You will need to install an extension such as Tampermonkey or Userscripts to install this script.

You will need to install an extension such as Tampermonkey to install this script.

You will need to install a user script manager extension to install this script.

(I already have a user script manager, let me install it!)

You will need to install an extension such as Stylus to install this style.

You will need to install an extension such as Stylus to install this style.

You will need to install an extension such as Stylus to install this style.

You will need to install a user style manager extension to install this style.

You will need to install a user style manager extension to install this style.

You will need to install a user style manager extension to install this style.

(I already have a user style manager, let me install it!)

// ==UserScript==
// @name         Snow Effect
// @namespace    http://tampermonkey.net/
// @version      1.0
// @description  Add a snow effect to any website
// @author       Masahiro Abe (modified for Tampermonkey by OpenAI Assistant)
// @match        *://drrrkari.com/*
// @grant        none
// ==/UserScript==

(function() {
    'use strict';

    // スタイルを挿入
    const style = document.createElement('style');
    style.textContent = `
        .snow {
            position: absolute;
            background-color: white;
            border-radius: 50%;
            z-index: 9999;
        }
    `;
    document.head.appendChild(style);

    // ATSnow クラス定義
    var ATSnow = function(vars) {
        var _self = this;
        var _snows = [];
        var _scrollHeight = 0;
        var _windowWidth = 0;
        var _windowHeight = 0;
        var _doc = document;

        var options = {
            classname: 'snow',
            count: 100,
            interval: 40,
            maxSize: 5,
            minSize: 1,
            leftMargin: 50,
            rightMargin: 50,
            bottomMargin: 30,
            maxDistance: 10,
            minDistance: 1
        };

        this.config = function(property) {
            for (var i in property) {
                if (!vars.hasOwnProperty(i)) {
                    continue;
                }
                options[i] = property[i];
            }
        };

        this.addEvent = function(eventTarget, eventName, func) {
            if (eventTarget.addEventListener) {
                eventTarget.addEventListener(eventName, func, false);
            } else if (window.attachEvent) {
                eventTarget.attachEvent('on' + eventName, function() { func.apply(eventTarget); });
            }
        };

        this.getScrollHeight = function() {
            if (_doc.documentElement.scrollHeight) {
                return _doc.documentElement.scrollHeight;
            } else {
                return _doc.body.scrollHeight;
            }
        };

        this.getRandomInt = function(min, max) {
            return Math.floor(Math.random() * (max - min + 1)) + min;
        };

        this.getWindowWidth = function() {
            return window.innerWidth || _doc.documentElement.clientWidth || _doc.body.clientWidth;
        };

        this.getWindowHeight = function() {
            return window.innerHeight || _doc.documentElement.clientHeight || _doc.body.clientHeight;
        };

        this.createSnow = function() {
            var body = _doc.body;

            for (var i = 0; i < options.count; i++) {
                var snow = _doc.createElement('div');
                snow.className = options.classname;
                var diameter = _self.getRandomInt(options.minSize, options.maxSize);
                snow.style.width = diameter + 'px';
                snow.style.height = diameter + 'px';

                _snows[i] = {};
                var snows = _snows[i];
                snows.ele = snow;
                snows.distance = _self.getRandomInt(options.minDistance, options.maxDistance);
                snows.degree = _self.getRandomInt(1, 10);
                snows.move = 0;
                snows.size = diameter;

                body.appendChild(snow);
            }
        };

        this.snowsPositionReset = function() {
            for (var i = 0; i < options.count; i++) {
                var topPosition = Math.floor(Math.random() * _scrollHeight);
                _self.snowPositionReset(_snows[i], topPosition - _scrollHeight);
            }
        };

        this.snowPositionReset = function(snow, y) {
            var leftPosition = _self.getRandomInt(options.leftMargin, _windowWidth - options.rightMargin);
            snow.ele.style.top = y + 'px';
            snow.ele.style.left = leftPosition + 'px';
            snow.x = leftPosition;
        };

        this.move = function() {
            var fall = function() {
                for (var i = 0; i < options.count; i++) {
                    var snow = _snows[i];
                    var top = parseInt(snow.ele.style.top) || 0;
                    snow.move += snow.degree;

                    if (top + snow.size >= _scrollHeight - options.bottomMargin) {
                        _self.snowPositionReset(snow, 0);
                    } else {
                        snow.ele.style.top = top + snow.size + 'px';
                        snow.ele.style.left = snow.x + Math.cos(snow.move * Math.PI / 180) * snow.distance + 'px';
                    }
                }
                setTimeout(function() { fall(); }, options.interval);
            };
            fall();
        };

        this.load = function() {
            _self.config(vars);

            _self.addEvent(window, 'load', function() {
                _scrollHeight = _self.getScrollHeight();
                _windowWidth = _self.getWindowWidth();
                _windowHeight = _self.getWindowHeight();
                _self.createSnow();
                _self.snowsPositionReset();
                _self.move();
            });

            _self.addEvent(window, 'resize', function() {
                _scrollHeight = _self.getScrollHeight();
                _windowWidth = _self.getWindowWidth();
                _windowHeight = _self.getWindowHeight();
                _self.snowsPositionReset();
            });
        };
    };

    // 雪エフェクトを起動
    var snowEffect = new ATSnow({
        count: 150, // 雪の数を変更可能
        maxSize: 8, // 雪の最大サイズ
        minSize: 2  // 雪の最小サイズ
    });
    snowEffect.load();
})();