最近发现友链的两位朋友的博客都有这个特效，后来对比了下这两个人的博客主题结构，就把这个特效扒了出来，鉴于今天有三个人都问了我这个效果怎么设置，故分享之。
首先加载一个js文件，js代码如下
代码语言：javascript复制(function webpackUniversalModuleDefinition(root, factory) {
if(typeof exports === 'object' && typeof module === 'object')
module.exports = factory();
else if(typeof define === 'function' && define.amd)
define([], factory);
else if(typeof exports === 'object')
exports["POWERMODE"] = factory();
else
root["POWERMODE"] = factory();
})(this, function() {
return /******/ (function(modules) { // webpackBootstrap
/******/ // The module cache
/******/ var installedModules = {};
/******/ // The require function
/******/ function __webpack_require__(moduleId) {
/******/ // Check if module is in cache
/******/ if(installedModules[moduleId])
/******/ return installedModules[moduleId].exports;
/******/ // Create a new module (and put it into the cache)
/******/ var module = installedModules[moduleId] = {
/******/ exports: {},
/******/ id: moduleId,
/******/ loaded: false
/******/ };
/******/ // Execute the module function
/******/ modules[moduleId].call(module.exports, module, module.exports, __webpack_require__);
/******/ // Flag the module as loaded
/******/ module.loaded = true;
/******/ // Return the exports of the module
/******/ return module.exports;
/******/ }
/******/ // expose the modules object (__webpack_modules__)
/******/ __webpack_require__.m = modules;
/******/ // expose the module cache
/******/ __webpack_require__.c = installedModules;
/******/ // __webpack_public_path__
/******/ __webpack_require__.p = "";
/******/ // Load entry module and return exports
/******/ return __webpack_require__(0);
/******/ })
/************************************************************************/
/******/ ([
/* 0 */
/***/ function(module, exports, __webpack_require__) {
'use strict';
var canvas = document.createElement('canvas');
canvas.width = window.innerWidth;
canvas.height = window.innerHeight;
canvas.style.cssText = 'position:fixed;top:0;left:0;pointer-events:none;z-index:999999';
window.addEventListener('resize', function () {
canvas.width = window.innerWidth;
canvas.height = window.innerHeight;
});
document.body.appendChild(canvas);
var context = canvas.getContext('2d');
var particles = [];
var particlePointer = 0;
var frames = 120;
var framesRemain = frames;
var rendering = false;
POWERMODE.shake = true;
function getRandom(min, max) {
return Math.random() * (max - min) min;
}
function getColor(el) {
if (POWERMODE.colorful) {
var u = getRandom(0, 360);
return 'hsla(' getRandom(u - 10, u 10) ', 100%, ' getRandom(50, 80) '%, ' 1 ')';
} else {
return window.getComputedStyle(el).color;
}
}
function getCaret() {
var el = document.activeElement;
var bcr;
if (el.tagName === 'TEXTAREA' ||
(el.tagName === 'INPUT' && el.getAttribute('type') === 'text')) {
var offset = __webpack_require__(1)(el, el.selectionStart);
bcr = el.getBoundingClientRect();
return {
x: offset.left bcr.left,
y: offset.top bcr.top,
color: getColor(el)
};
}
var selection = window.getSelection();
if (selection.rangeCount) {
var range = selection.getRangeAt(0);
var startNode = range.startContainer;
if (startNode.nodeType === document.TEXT_NODE) {
startNode = startNode.parentNode;
}
bcr = range.getBoundingClientRect();
return {
x: bcr.left,
y: bcr.top,
color: getColor(startNode)
};
}
return { x: 0, y: 0, color: 'transparent' };
}
function createParticle(x, y, color) {
return {
x: x,
y: y,
alpha: 1,
color: color,
velocity: {
x: -1 Math.random() * 2,
y: -3.5 Math.random() * 2
}
};
}
function POWERMODE() {
{ // spawn particles
var caret = getCaret();
var numParticles = 5 Math.round(Math.random() * 10);
while (numParticles--) {
particles[particlePointer] = createParticle(caret.x, caret.y, caret.color);
particlePointer = (particlePointer 1) % 500;
}
framesRemain = frames;
if (!rendering) {
requestAnimationFrame(loop);
}
}
{ // shake screen
if (POWERMODE.shake) {
var intensity = 1 2 * Math.random();
var x = intensity * (Math.random() > 0.5 ? -1 : 1);
var y = intensity * (Math.random() > 0.5 ? -1 : 1);
document.body.style.marginLeft = x 'px';
document.body.style.marginTop = y 'px';
setTimeout(function() {
document.body.style.marginLeft = '';
document.body.style.marginTop = '';
}, 75);
}
}
};
POWERMODE.colorful = false;
function loop() {
if (framesRemain > 0) {
requestAnimationFrame(loop);
framesRemain--;
rendering = true;
} else {
rendering = false;
}
context.clearRect(0, 0, canvas.width, canvas.height);
for (var i = 0; i < particles.length; i) {
var particle = particles[i];
if (particle.alpha <= 0.1) continue;
particle.velocity.y = 0.075;
particle.x = particle.velocity.x;
particle.y = particle.velocity.y;
particle.alpha *= 0.96;
context.globalAlpha = particle.alpha;
context.fillStyle = particle.color;
context.fillRect(
Math.round(particle.x - 1.5),
Math.round(particle.y - 1.5),
3, 3
);
}
}
requestAnimationFrame(loop);
module.exports = POWERMODE;
/***/ },
/* 1 */
/***/ function(module, exports) {
/* jshint browser: true */
(function () {
// The properties that we copy into a mirrored div.
// Note that some browsers, such as Firefox,
// do not concatenate properties, i.e. padding-top, bottom etc. -> padding,
// so we have to do every single property specifically.
var properties = [
'direction', // RTL support
'boxSizing',
'width', // on Chrome and IE, exclude the scrollbar, so the mirror div wraps exactly as the textarea does
'height',
'overflowX',
'overflowY', // copy the scrollbar for IE
'borderTopWidth',
'borderRightWidth',
'borderBottomWidth',
'borderLeftWidth',
'borderStyle',
'paddingTop',
'paddingRight',
'paddingBottom',
'paddingLeft',
// https://developer.mozilla.org/en-US/docs/Web/CSS/font
'fontStyle',
'fontVariant',
'fontWeight',
'fontStretch',
'fontSize',
'fontSizeAdjust',
'lineHeight',
'fontFamily',
'textAlign',
'textTransform',
'textIndent',
'textDecoration', // might not make a difference, but better be safe
'letterSpacing',
'wordSpacing',
'tabSize',
'MozTabSize'
];
var isFirefox = window.mozInnerScreenX != null;
function getCaretCoordinates(element, position, options) {
var debug = options && options.debug || false;
if (debug) {
var el = document.querySelector('#input-textarea-caret-position-mirror-div');
if ( el ) { el.parentNode.removeChild(el); }
}
// mirrored div
var div = document.createElement('div');
div.id = 'input-textarea-caret-position-mirror-div';
document.body.appendChild(div);
var style = div.style;
var computed = window.getComputedStyle? getComputedStyle(element) : element.currentStyle; // currentStyle for IE < 9
// default textarea styles
style.whiteSpace = 'pre-wrap';
if (element.nodeName !== 'INPUT')
style.wordWrap = 'break-word'; // only for textarea-s
// position off-screen
style.position = 'absolute'; // required to return coordinates properly
if (!debug)
style.visibility = 'hidden'; // not 'display: none' because we want rendering
// transfer the element's properties to the div
properties.forEach(function (prop) {
style[prop] = computed[prop];
});
if (isFirefox) {
// Firefox lies about the overflow property for textareas: https://bugzilla.mozilla.org/show_bug.cgi?id=984275
if (element.scrollHeight > parseInt(computed.height))
style.overflowY = 'scroll';
} else {
style.overflow = 'hidden'; // for Chrome to not render a scrollbar; IE keeps overflowY = 'scroll'
}
div.textContent = element.value.substring(0, position);
// the second special handling for input type="text" vs textarea: spaces need to be replaced with non-breaking spaces - http://stackoverflow.com/a/13402035/1269037
if (element.nodeName === 'INPUT')
div.textContent = div.textContent.replace(/s/g, "u00a0");
var span = document.createElement('span');
// Wrapping must be replicated *exactly*, including when a long word gets
// onto the next line, with whitespace at the end of the line before (#7).
// The *only* reliable way to do that is to copy the *entire* rest of the
// textarea's content into the created at the caret position.
// for inputs, just '.' would be enough, but why bother?
span.textContent = element.value.substring(position) || '.'; // || because a completely empty faux span doesn't render at all
div.appendChild(span);
var coordinates = {
top: span.offsetTop parseInt(computed['borderTopWidth']),
left: span.offsetLeft parseInt(computed['borderLeftWidth'])
};
if (debug) {
span.style.backgroundColor = '#aaa';
} else {
document.body.removeChild(div);
}
return coordinates;
}
if (typeof module != "undefined" && typeof module.exports != "undefined") {
module.exports = getCaretCoordinates;
} else {
window.getCaretCoordinates = getCaretCoordinates;
}
}());
/***/ }
/******/ ])
});
;然后在加入下面的代码即可
代码语言：javascript复制<script>
POWERMODE.colorful = true; // make power mode colorful
POWERMODE.shake = false; // turn off shake
document.body.addEventListener('input', POWERMODE);
</script>
