javascript轉(zhuǎn)換靜態(tài)圖片，增加粒子動畫效果
更新時間：2015年05月28日 09:41:23 投稿：hebedich
這篇文章主要介紹了javascript轉(zhuǎn)換靜態(tài)圖片，增加粒子動畫效果,非常的炫酷，需要的朋友可以參考下
使用getImageData接口獲取圖片的像素點，然后基于像素點實現(xiàn)動畫效果，封裝成一個簡單的lib
<!DOCTYPE html>
<html>
<head>
<title>particle image</title>
<meta charset="utf-8" />
<style>
#logo {
margin-left:20px;
margin-top:20px;
width:160px;
height:48px;
background:url('./images/logo.png');
/*border: 1px solid red;*/
}
</style>
<script type="text/javascript" src="ParticleImage.js"></script>
<script>
window.onload = function() {
ParticleImage.create("logo", "./images/logo.png", "fast");
};
</script>
</head>
<body>
<div id="logo"></div>
</body>
</html>
ParticleImage.js
/*
The MIT License (MIT)
Copyright (c) 2015 arest
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.
*/
/**
* Add particle animation for image
* usage:
<script type="text/javascript" src="ParticleImage.js"></script>
<script>
window.onload = function() {
// be sure to use image file in your own server (prevent CORS issue)
ParticleImage.create("logo", "logo_s2.png", "fast");
};
</script>
// in html file
<div id="logo"></div>
// you can set default background image as usual
#logo {
margin-left:20px;
margin-top:20px;
width:160px;
height:48px;
background:url('logo_s2.png');
}
*
* @author tianx.qin (rushi_wowen@163.com)
* @file ParticleImage.js
* @version 0.9
*/
var ParticleImage = (function(window) {
var container = null, canvas = null;
var ctx = null, _spirit = [], timer = null,
cw = 0, ch = 0, // container width/height
iw = 0, ih = 0, // image width/height
mx = 0, my = 0, // mouse position
bMove = true,
MOVE_SPAN = 4, DEFAULT_ALPHA = 100,
speed = 100, S = {"fast":10, "mid":100, "low":300},
ALPHA = 255 * 255;
// spirit class
var Spirit = function(data) {
this.orginal = {
pos: data.pos,
x : data.x, y : data.y,
r : data.r, g : data.g, b : data.b, a : data.a
};
// change state, for animation
this.current = {
x : data.x,
y : data.y,
a : data.a
};
};
/**
* move spirit to original position
*/
Spirit.prototype.move = function() {
var cur = this.current, orig = this.orginal;
if ((cur.x === orig.x) && (cur.y === orig.y)) {
//console.log("don't move:" + cur.y);
return false;
}
//console.log("move:" + cur.y);
var rand = 1 + Math.round(MOVE_SPAN * Math.random());
var offsetX = cur.x - orig.x,
offsetY = cur.y - orig.y;
var rad = offsetX == 0 ? 0 : offsetY / offsetX;
var xSpan = cur.x < orig.x ? rand : cur.x > orig.x ? -rand : 0;
cur.x += xSpan;
var tempY = xSpan == 0 ? Math.abs(rand) : Math.abs(Math.round(rad * xSpan));
var ySpan = offsetY < 0 ? tempY : offsetY > 0 ? -tempY : 0;
cur.y += ySpan;
cur.a = ((cur.x === orig.x) && (cur.y === orig.y)) ? orig.a : DEFAULT_ALPHA;
return true;
};
/**
* set random position
*/
Spirit.prototype.random = function(width, height) {
var cur = this.current;
cur.x = width + Math.round(width * 2 * Math.random());
this.current.y = height + Math.round(height * 2 * Math.random());
};
/**
* set random positions for all spirits
*/
var _disorder = function() {
var len = _spirit.length;
for (var i = 0; i < len; i++) {
_spirit[i].random(cw, ch);
}
};
/**
* start to move spirit
*/
var _move = function() {
var sprt = _spirit;
var len = sprt.length;
var isMove = false; // whether need to move
for (var i = 0; i < len; i++) {
if (sprt[i].move()) {
isMove = true;
}
}
isMove ? _redraw() : _stopTimer();
};
/**
* redraw all spirits while animating
*/
var _redraw = function() {
var imgDataObj = ctx.createImageData(iw, ih);
var imgData = imgDataObj.data;
var sprt = _spirit;
var len = sprt.length;
//console.log("redraw image : " + len);
for (var i = 0; i < len; i++) {
var temp = sprt[i];
//console.log("item : " + JSON.stringify(temp));
var orig = temp.orginal;
var cur = temp.current;
var pos = (cur.y * iw + cur.x) * 4;
imgData[pos] = orig.r;
imgData[pos + 1] = orig.g;
imgData[pos + 2] = orig.b;
imgData[pos + 3] = cur.a;
}
ctx.putImageData(imgDataObj, 0, 0);
};
/**
* add mousemove/mouseclick event
*/
var _addMouseEvent = function(c) {
c.addEventListener("mouseenter", function(e) {
//console.log("e.y:" + e.clientY + ", " + container.offsetTop);
_startTimer();
});
c.addEventListener("click", function() {
// disorder all spirits and start animation
_startTimer();
});
};
/**
* calculate all pixels of the logo image
*/
var _checkImage = function(imgUrl, callback) {
// var tempCanvas = document.getElementById("temp");
//canvas.width = width;
//canvas.height = height;
var proc = function(image) {
var w = image.width, h = image.height;
iw = w, ih = h;
//console.log("proc image " + image + "," + w + "," + h);
canvas = _createCanvas();
// hide container background
container.style.backgroundPosition = (-w) + "px";
container.style.backgroundRepeat = "no-repeat";
ctx.drawImage(image, 0, 0);
// this may cause security error for CORS issue
try {
var imgData = ctx.getImageData(0, 0, w, h);
var arrData = imgData.data;
for (var i = 0; i < arrData.length; i += 4) {
var r = arrData[i], g = arrData[i + 1], b = arrData[i + 2], a = arrData[i + 3];
if (r > 0 || g > 0 || b > 0 || a > 0) {
var pos = i / 4;
_spirit.push(new Spirit({
x : pos % w, y : Math.floor(pos / w),
r : r, g : g, b : b, a : a
}));
}
}
return true;
} catch (e) {
// do nothing
return false;
}
//return out;
};
var img = new Image();
img.src = imgUrl;
if (img.complete || img.complete === undefined) {
proc(img) && callback && callback();
} else {
img.onload = function() {
proc(img) && callback && callback();
};
}
};
// use "requestAnimationFrame" to create a timer, need browser support
var _timer = function(func, dur) {
//console.log("speed is " + dur);
var timeLast = null;
var bStop = false;
var bRunning = false; // prevent running more than once
var _start = function() {
if (func) {
if (! timeLast) {
timeLast = Date.now();
func();
} else {
var current = Date.now();
if (current - timeLast >= dur) {
timeLast = current;
func();
}
}
}
if (bStop) {
return;
}
requestAnimationFrame(_start);
};
var _stop = function() {
bStop = true;
};
return {
start : function() {
if (bRunning) {
//console.log("already running..");
return;
}
//console.log("start running..");
bRunning = true;
bStop = false;
_disorder();
_start();
},
stop : function() {
_stop();
bRunning = false;
}
};
};
var _startTimer = function() {
if (! timer) {
timer = _timer(function() {
bMove && _move();
}, speed);
}
timer.start();
};
var _stopTimer = function() {
timer && timer.stop();
};
/**
* start process
*/
var _create = function(imgUrl) {
_checkImage(imgUrl, function() {
//_createSpirits();
_addMouseEvent(canvas);
//_startTimer();
});
};
var _setSpeed = function(s) {
S[s] && (speed = S[s]);
};
/**
* check whether browser supports canvas
*/
var _support = function() {
try {
document.createElement("canvas").getContext("2d");
return true;
} catch (e) {
return false;
}
};
/**
* create a canvas element
*/
var _createCanvas = function() {
var cav = document.createElement("canvas");
cav.width = iw;
cav.height = ih;
container.appendChild(cav);
ctx = cav.getContext("2d");
return cav;
};
/**
* initialize container params
*/
var _init = function(c, s) {
if ((! c) || (! _support())) { // DIV id doesn't exist
return false;
}
container = c;
cw = c.clientWidth;
ch = c.clientHeight;
s && _setSpeed(s);
return true;
};
/**
* export
*/
return {
"create" : function(cId, imgUrl, s) { // user can set move speed by 's'['fast','mid','low']
_init(document.getElementById(cId), s) && _create(imgUrl);
}
};
})(window);
以上所述就是本文的全部內(nèi)容了，希望大家能夠喜歡。
相關(guān)文章
在動態(tài)頁面中，頁面中包含一些動態(tài)產(chǎn)生的控件，在有些情況下需要判斷動態(tài)生成的控件是否存在。2010-08-08
這篇文章主要介紹了js實現(xiàn)滾動條滾動到某個位置便自動定位某個tr的相關(guān)資料，文中示例代碼介紹的非常詳細(xì)，具有一定的參考價值，感興趣的小伙伴們可以參考一下2016-01-01
這篇文章介紹了js同比例縮放圖片的小例子，有需要的朋友可以參考一下2013-10-10
下拉選擇框想必大家并不陌生，一邊情況下都是使用默認(rèn)的，為了打破傳統(tǒng)，下面與大家分享下使用js自定義下拉選擇框示例代碼,感興趣的朋友可以參考下2013-08-08
JavaScript中的普通函數(shù)和箭頭函數(shù)的區(qū)別和用法詳解
這篇文章主要介紹了JavaScript中的普通函數(shù)和箭頭函數(shù)的區(qū)別和用法詳解,非常不錯，具有參考借鑒價值，需要的朋友可以參考下2017-03-03
這篇文章主要為大家詳細(xì)介紹了微信小程序?qū)崿F(xiàn)日期格式化，文中示例代碼介紹的非常詳細(xì)，具有一定的參考價值，感興趣的小伙伴們可以參考一下2022-07-07
這篇文章主要介紹了js replace替換字符串同時替換多個方法 的相關(guān)資料,需要的朋友可以參考下2018-11-11
js學(xué)習(xí)總結(jié)_輪播圖之漸隱漸現(xiàn)版(實例講解)
下面小編就為大家?guī)硪黄猨s學(xué)習(xí)總結(jié)_輪播圖之漸隱漸現(xiàn)版(實例講解)。小編覺得挺不錯的，現(xiàn)在就分享給大家，也給大家做個參考。一起跟隨小編過來看看吧2017-07-07
這篇文章主要為大家詳細(xì)介紹了基于javascript制作微信聊天面板的相關(guān)資料，文中示例代碼介紹的非常詳細(xì)，具有一定的參考價值，感興趣的小伙伴們可以參考一下2016-03-03
所謂偽數(shù)組,指的是具有類似數(shù)組結(jié)構(gòu)的對象,但并非真正的數(shù)組,在本文中,我們將詳細(xì)介紹偽數(shù)組的特點和特征,并提供一些JavaScript代碼示例,感興趣的小伙伴快跟隨小編一起學(xué)習(xí)起來吧2023-11-11