原生js操作图片缩放，但是transformorigin变化时图片会发生位移，所有代码如下,麻烦指点
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<meta name="viewport"
content="width=device-width,initial-scale=1,minimum-scale=1,maximum-scale=1,user-scalable=no" />
<title></title>
<script src="js/mui.min.js"></script>
<link href="css/mui.min.css" rel="stylesheet" />
<script type="text/javascript" charset="utf-8">
mui.init();
</script>
<style>
#image{
will-change: transform;
}
</style>
</head>
<body>
<div style="height: 300px;">
</div>
<div id="container" style="align-items: center;">
<img id="image" style="border: 1px solid red;width: 100%;"
src="https://www.akailibrary.com/wp-content/uploads/2020/05/1589443043-3784896.jpg" alt="">
</div>
</body>
<style>
#image{
translate: 0;
}
</style>
<script>
var isTouch = false; //点击
var isDoubleTouch = false; //是否为多触点
var start = []; //存放触点坐标
var timer = null;
var now, delta; //当前时间，两次触发事件时间差
var startPosition, movePosition, endPosition; //滑动起点，移动，结束点坐标
//事件声明
var gesturestart = new CustomEvent('gesturestart');
var gesturechange = new CustomEvent('gesturechange');
var gestureend = new CustomEvent('gestureend');
var swipeMove = new CustomEvent('swipeMove');
var doubleTouch = new CustomEvent("doubleTouch");
var doubleTouchReduce = new CustomEvent("doubleTouchReduce");
let dbcl = 1;//设置双击退出和进入的
let slsc;//设置滑动放大时的位置
let trso;//放大起源
let sc;
var store = {
scale: 1
};
var image = document.getElementById('image');
//监听touchstart事件
image.addEventListener('touchstart', function(e) {
if (e.touches.length >= 2) { //判断是否有两个点在屏幕上
console.log('两个点在屏幕上');
isDoubleTouch = true;
start = e.touches; //得到第一组两个点 闹钟电脑 126... 83...
console.log('tMatrix[0]',parseFloat(tMatrix[0]));
// if(tMatrix[0]>1){
// let rect = image.getBoundingClientRect();
// let left = -rect.left;
// let top = rect.top;
// //第1个点x总长
// let fzcx = e.touches[0].pageX + left;
// //第1个点x相对缩小
// let fxdsx = fzcx/tMatrix[0].toFixed(2)
// console.log('一样的大小',fxdsx);
// //第2个点x总长
// let szcx = e.touches[1].pageX + left;
// //第2个点x相对缩小
// let sxdsx = szcx/tMatrix[0].toFixed(2)
// console.log('一样的大小',sxdsx);
// let top1;
// let fzcy;
// let fxdsy;
// let szcy;
// let sxdsy;
// if(top<0){
// top1 = -top;
// fzcy = e.touches[0].pageY + top1;
// fxdsy = fzcy/tMatrix[3].toFixed(2)
// szcy = e.touches[1].pageY + top1;
// sxdsy = szcy/tMatrix[3].toFixed(2)
// }else{
// fzcy = e.touches[0].pageY - top;
// fxdsy = fzcy/tMatrix[3].toFixed(2)
// szcy = e.touches[1].pageY - top;
// sxdsy = szcy/tMatrix[3].toFixed(2)
// }
// var screenMinPoint1 = getMidpoint1(fxdsx,fxdsy,sxdsx,sxdsy); //获取两个触点中心坐标
// console.log('放大一次后的放大中点',screenMinPoint1)
// gesturestart.midPoint = screenMinPoint1;
// e.target.dispatchEvent(gesturestart);
// }else{
var screenMinPoint = getMidpoint(start[0], start[1]); //获取两个触点中心坐标
let dycfdzd = [screenMinPoint[0] - e.target.offsetLeft, screenMinPoint[1] - e.target.offsetTop]
console.log('第一次放大的中点',dycfdzd);
gesturestart.midPoint = [screenMinPoint[0] - e.target.offsetLeft, screenMinPoint[1] - e.target.offsetTop]; //获取中心点坐标相对目标元素坐标
e.target.dispatchEvent(gesturestart);
// }
} else {
// console.log('一个点在屏幕上');
delta = Date.now() - now; //计算两次点击时间差
// console.log('时间差',delta);
now = Date.now();
startPosition = [e.touches[0].pageX, e.touches[0].pageY]; //点击位置距离屏幕左侧距离，点击位置距离屏幕顶部距离
// console.log('当前点击的在页面中的位置：',startPosition);
// console.log('点击的位置',startPosition[0]);
// let rect = image.getBoundingClientRect();
// let left = -rect.left;
// console.log('left',left);
// if(tMatrix[0]>1){
// let wd = (left + e.touches[0].pageX)/tMatrix[0];
// console.log('wd',wd)
// }
if (dbcl == 1) {
if (delta > 0 && delta <= 250) { //双击事件
// console.log('双击事件放大');
// clearTimeout(timer);
doubleTouch.position = [e.touches[0].pageX - e.target.offsetLeft, e.touches[0].pageY - e
.target.offsetTop
];
// console.log('点击位置距离当前所在盒子的距离',doubleTouch.position);
e.target.dispatchEvent(doubleTouch);
dbcl = 2;
} else {
// console.log('单击退出事件');
// alert('11')
// timer = setTimeout(function(){ //单击事件
// e.target.dispatchEvent(oneTouch);
// })
}
} else {
if (delta > 0 && delta <= 250) { //双击事件
// console.log('双击事件缩小');
clearTimeout(timer);
doubleTouch.position = [e.touches[0].pageX - e.target.offsetLeft, e.touches[0].pageY - e.target.offsetTop];
// console.log('点击位置距离当前所在盒子的距离',doubleTouch.position);
e.target.dispatchEvent(doubleTouchReduce);
dbcl = 1;
} else { //滑动事件
// timer = setTimeout(function(){ //单击事件
// e.target.dispatchEvent(oneTouch);
// })
}
}
isTouch = true;
}
}, false);
//监听touchmove事件
image.addEventListener('touchmove', function(e) {
console.log('进入缩放');
clearTimeout(timer);
if (e.touches.length >= 2 && isDoubleTouch) { //手势事件
console.log('缩放');
var now = e.touches; //得到第二组两个点
// console.log('now',now);
var scale = getDistance(now[0], now[1]) / getDistance(start[0], start[1]); //得到缩放比例
// console.log('scale缩放比例', scale);
// var rotation = getAngle(now[0], now[1]) - getAngle(start[0], start[1]); //得到旋转角度差
gesturechange.scale = scale.toFixed(2);
// gesturechange.rotation = rotation.toFixed(2);
e.target.dispatchEvent(gesturechange);
} else if (isTouch) {
// movePosition = [e.touches[0].pageX, e.touches[0].pageY];
// endPosition = movePosition;
// movePosition = [movePosition[0] - startPosition[0], movePosition[1] - startPosition[1]];
// startPosition = [e.touches[0].pageX, e.touches[0].pageY];
// swipeMove.distance =[movePosition[0].toFixed(2) , movePosition[1].toFixed(2)];
// e.target.dispatchEvent(swipeMove);
}
}, false);
/* 两点的距离 */
function getDistance(p1, p2) {
var x = p2.pageX - p1.pageX,
y = p2.pageY - p1.pageY;
return Math.sqrt((x * x) + (y * y));
};
/* 获取中点 */
function getMidpoint(p1, p2) {
var x = (p1.pageX + p2.pageX) / 2,
y = (p1.pageY + p2.pageY) / 2;
return [x, y];
}
/* 获取中点2 */
function getMidpoint1(x1,y1,x2,y2) {
var x = (x1 + x2) / 2,
y = (y1 + y2) / 2;
return [x, y];
}
image.addEventListener('doubleTouch', gesture, false);
image.addEventListener('doubleTouchReduce', gesture, false);
image.addEventListener('gesturestart', gesture, false);
image.addEventListener('gesturechange', gesture, false);
var tMatrix = [1, 0, 0, 1, 0, 0]; //x缩放，无，无，y缩放，x平移，y平移
function gesture(event) {
switch (event.type) {
case "doubleTouch":
originLast = event.position;
// console.log('点击位置距离当前所在盒子的距离',originLast);
//transformOrigin变形原点，该属性只有在设置了transform属性的时候起作用
image.style.transformOrigin = event.position[0] + "px " + event.position[1] + "px";
console.log('进入双击',image.style.transformOrigin)
tMatrix[0] = 4;
tMatrix[3] = 4;
//把数组分隔成字符串
var temp = tMatrix.join(",");
// console.log('temp',temp);
//设置缩放或者3旋转啥的
image.style.transform = "matrix(" + temp + ")";
// console.log('image.style.transform',image.style.transform);
// maxMove();
break;
case "doubleTouchReduce":
// console.log('进入缩小');
tMatrix[0] = 1;
tMatrix[3] = 1;
var temp = tMatrix.join(",");
image.style.transform = "matrix(" + temp + ")";
break;
//监听 gesturestart 设置 变换中心
case "gesturestart":
originLast = event.midPoint;
// console.log('originLast',originLast);
image.style.transformOrigin = event.midPoint[0] + "px " + event.midPoint[1] + "px";
image.style.translate = event.midPoint[0] + "px " + event.midPoint[1] + "px";
// image.style.translate = event.midPoint[0].toFixed(2) + "px " + event.midPoint[1].toFixed(2) + "px";
// image.style.transformOrigin = 222.182 + "px " + 131.818 + "px";
console.log('进入双击2',image.style.transformOrigin,image.style.translate);
break;
case "gesturechange":
sc = parseFloat(event.scale);
// image.style.transformOrigin = trso;
if ( sc > 0.6) {
tMatrix[0] = tMatrix[0] + sc - 1 > 1 && tMatrix[0] + sc - 1 < 10 ? tMatrix[0] + sc - 1 : tMatrix[0];
// console.log('tMatrix[0]', tMatrix[0])
tMatrix[3] = tMatrix[3] + sc - 1 > 1 && tMatrix[3] + sc - 1 < 10 ? tMatrix[3] + sc - 1 : tMatrix[3];
// console.log('tMatrix[3]', tMatrix[3])
var temp = tMatrix.join(",");
// console.log('temp',temp);
image.style.transform = "matrix(" + temp + ")";
console.log('image.style.transform',image.style.transform)
console.log('情况',tMatrix[0].toFixed(2) )
image.style.transition = "transform 0.1s linear";
slsc = 1;
// console.log('image.style.transformOrigin',image.style.transformOrigin);
} else {
tMatrix[0] = 1;
console.log('tMatrix[0]', tMatrix[0])
tMatrix[3] = 1;
console.log('tMatrix[3]', tMatrix[3])
var temp = tMatrix.join(",");
image.style.transform = "matrix(" + temp + ")";
image.style.transition = "transform 0.1s linear";
// console.log('image.style.transformOrigin',image.style.transformOrigin);
}
dbcl = 2;
break;
}
}
</script>
</html>
