本篇文章为大家展示了使用JavaScript项目编写一个图片抖动放大效果，内容简明扼要并且容易理解，绝对能使你眼前一亮，通过这篇文章的详细介绍希望你能有所收获。
var xm;
var ym;
/* ==== onmousemove event ==== */
document.onmousemove = function(e){
if(window.event) e=window.event;
xm = (e.x || e.clientX);
ym = (e.y || e.clientY);
}
/* ==== window resize ==== */
function resize() {
if(diapo)diapo.resize();
}
onresize = resize;
/* ==== opacity ==== */
setOpacity = function(o, alpha){
if(o.filters)o.filters.alpha.opacity = alpha * 100; else o.style.opacity = alpha;
}
/* ===== encapsulate script ==== */
diapo = {
O : [],
DC : 0,
img : 0,
txt : 0,
N : 0,
xm : 0,
ym : 0,
nx : 0,
ny : 0,
nw : 0,
nh : 0,
rs : 0,
rsB : 0,
zo : 0,
tx_pos : 0,
tx_var : 0,
tx_target : 0,
/// script parameters
attraction : 2,
acceleration : .9,
dampening : .1,
zoomOver : 2,
zoomClick : 6,
transparency : .8,
font_size: 18,
//
/* ==== diapo resize ==== */
resize : function(){
with(this){
nx = DC.offsetLeft;
ny = DC.offsetTop;
nw = DC.offsetWidth;
nh = DC.offsetHeight;
txt.style.fontSize = Math.round(nh / font_size) + "px";
if(Math.abs(rs-rsB)<100) for(var i=0; i<N; i++) O[i].resize();
rsB = rs;
}
},
/* ==== create diapo ==== */
CDiapo : function(o){
/* ==== init variables ==== */
this.o = o;
this.x_pos = this.y_pos = 0;
this.x_origin = this.y_origin = 0;
this.x_var = this.y_var = 0;
this.x_target = this.y_target = 0;
this.w_pos = this.h_pos = 0;
this.w_origin = this.h_origin = 0;
this.w_var = this.h_var = 0;
this.w_target = this.h_target = 0;
this.over = false;
this.click = false;
/* ==== create shadow ==== */
this.spa = document.createElement("span");
this.spa.className = "spaDC";
diapo.DC.appendChild(this.spa);
/* ==== create thumbnail image ==== */
this.img = document.createElement("img");
this.img.className = "imgDC";
this.img.src = o.src;
this.img.O = this;
diapo.DC.appendChild(this.img);
setOpacity(this.img, diapo.transparency);
/* ==== mouse events ==== */
this.img.onselectstart = new Function("return false;");
this.img.ondrag = new Function("return false;");
this.img.onmouseover = function(){
diapo.tx_target=0;
diapo.txt.innerHTML=this.O.o.alt;
this.O.over=true;
setOpacity(this,this.O.click?diapo.transparency:1);
}
this.img.onmouseout = function(){
diapo.tx_target=-diapo.nw;
this.O.over=false;
setOpacity(this,diapo.transparency);
}
this.img.onclick = function() {
if(!this.O.click){
if(diapo.zo && diapo.zo != this) diapo.zo.onclick();
this.O.click = true;
this.O.x_origin = (diapo.nw - (this.O.w_origin * diapo.zoomClick)) / 2;
this.O.y_origin = (diapo.nh - (this.O.h_origin * diapo.zoomClick)) / 2;
diapo.zo = this;
setOpacity(this,diapo.transparency);
} else {
this.O.click = false;
this.O.over = false;
this.O.resize();
diapo.zo = 0;
}
}
/* ==== rearrange thumbnails based on "imgsrc" images position ==== */
this.resize = function (){
with (this) {
x_origin = o.offsetLeft;
y_origin = o.offsetTop;
w_origin = o.offsetWidth;
h_origin = o.offsetHeight;
}
}
/* ==== animation function ==== */
this.position = function (){
with (this) {
/* ==== set target position ==== */
w_target = w_origin;
h_target = h_origin;
if(over){
/* ==== mouse over ==== */
w_target = w_origin * diapo.zoomOver;
h_target = h_origin * diapo.zoomOver;
x_target = diapo.xm - w_pos / 2 - (diapo.xm - (x_origin + w_pos / 2)) / (diapo.attraction*(click?10:1));
y_target = diapo.ym - h_pos / 2 - (diapo.ym - (y_origin + h_pos / 2)) / (diapo.attraction*(click?10:1));
} else {
/* ==== mouse out ==== */
x_target = x_origin;
y_target = y_origin;
}
if(click){
/* ==== clicked ==== */
w_target = w_origin * diapo.zoomClick;
h_target = h_origin * diapo.zoomClick;
}
/* ==== magic spring equations ==== */
x_pos += x_var = x_var * diapo.acceleration + (x_target - x_pos) * diapo.dampening;
y_pos += y_var = y_var * diapo.acceleration + (y_target - y_pos) * diapo.dampening;
w_pos += w_var = w_var * (diapo.acceleration * .5) + (w_target - w_pos) * (diapo.dampening * .5);
h_pos += h_var = h_var * (diapo.acceleration * .5) + (h_target - h_pos) * (diapo.dampening * .5);
diapo.rs += (Math.abs(x_var) + Math.abs(y_var));
/* ==== html animation ==== */
with(img.style){
left = Math.round(x_pos) + "px";
top = Math.round(y_pos) + "px";
width = Math.round(Math.max(0, w_pos)) + "px";
height = Math.round(Math.max(0, h_pos)) + "px";
zIndex = Math.round(w_pos);
}
with(spa.style){
left = Math.round(x_pos + w_pos * .1) + "px";
top = Math.round(y_pos + h_pos * .1) + "px";
width = Math.round(Math.max(0, w_pos * 1.1)) + "px";
height = Math.round(Math.max(0, h_pos * 1.1)) + "px";
zIndex = Math.round(w_pos);
}
}
}
},
/* ==== main loop ==== */
run : function(){
diapo.xm = xm - diapo.nx;
diapo.ym = ym - diapo.ny;
/* ==== caption anim ==== */
diapo.tx_pos += diapo.tx_var = diapo.tx_var * .9 + (diapo.tx_target - diapo.tx_pos) * .02;
diapo.txt.style.left = Math.round(diapo.tx_pos) + "px";
/* ==== images anim ==== */
for(var i in diapo.O) diapo.O[i].position();
/* ==== loop ==== */
setTimeout("diapo.run();", 16);
},
/* ==== load images ==== */
images_load : function(){
// ===== loop until all images are loaded =====
var M = 0;
for(var i=0; i<diapo.N; i++) {
if(diapo.img[i].complete) {
diapo.img[i].style.position = "relative";
diapo.O[i].img.style.visibility = "visible";
diapo.O[i].spa.style.visibility = "visible";
M++;
}
resize();
}
if(M<diapo.N) setTimeout("diapo.images_load();", 128);
},
/* ==== init script ==== */
init : function() {
diapo.DC = document.getElementById("diapoContainer");
diapo.img = diapo.DC.getElementsByTagName("img");
diapo.txt = document.getElementById("caption");
diapo.N = diapo.img.length;
for(i=0; i<diapo.N; i++) diapo.O.push(new diapo.CDiapo(diapo.img[i]));
diapo.resize();
diapo.tx_pos = -diapo.nw;
diapo.tx_target = -diapo.nw;
diapo.images_load();
diapo.run();
}
}
/* ==== start script ==== */
function dom_onload() {
if(document.getElementById("diapoContainer")) diapo.init(); else setTimeout("dom_onload();", 128);
}
dom_onload();上述内容就是使用JavaScript项目编写一个图片抖动放大效果，你们学到知识或技能了吗？如果还想学到更多技能或者丰富自己的知识储备，欢迎关注亿速云行业资讯频道。
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