HTML5 Canvas实现360度全景图的示例代码

2020-04-21 23:14:01易采站长站整理

很多购物网站现在都支持360实物全景图像,可以360度任意选择查看样品,这样对购买者来说是一个很好的消费体验,网上有很多这样的插件都是基于jQuery实现的有收费的也有免费的,其实很好用的一个叫3deye.js的插件。该插件支持桌面与移动终端iOS与Android, 它的demo程序:http://huoche.7234.cn/images/jb51/gq3ontddan5.jpg";
}
else
{
images[i] = new Image();
images[i].src = i + ".jpg";
}
}
ctx = canvas.getContext("2d");

// mouse event
canvas.addEventListener("mousedown", doMouseDown, false);
canvas.addEventListener(‘mousemove’, doMouseMove, false);
canvas.addEventListener(‘mouseup’, doMouseUp, false);
// loaded();

// frame = 1
frame = 1;
images[frame].onload = function() {
redraw();
bar.style.display = ‘none’;
}
}
function doMouseDown(event) {
var x = event.pageX;
var y = event.pageY;
var canvas = event.target;
var loc = getPointOnCanvas(canvas, x, y);
console.log("mouse down at point( x:" + loc.x + ", y:" + loc.y + ")");
startedX = loc.x;
started = true;
}

function doMouseMove(event) {
var x = event.pageX;
var y = event.pageY;
var canvas = event.target;
var loc = getPointOnCanvas(canvas, x, y);
if (started) {
var count = Math.floor(Math.abs((startedX – loc.x)/30));
var frameIndex = Math.floor((startedX – loc.x)/30);
while(count > 0)
{
console.log("frameIndex = " + frameIndex);
count–;
if(frameIndex > 0)
{
frameIndex–;
frame++;
} else if(frameIndex < 0)
{
frameIndex++;
frame–;
}
else if(frameIndex == 0)
{
break;
}

if(frame >= 24)
{
frame = 1;
}
if(frame <= 0)
{
frame = 23;
}
redraw();
}
}
}

function doMouseUp(event) {
console.log("mouse up now");
if (started) {
doMouseMove(event);
startedX = -1;
started = false;
}
}

function getPointOnCanvas(canvas, x, y) {
var bbox = canvas.getBoundingClientRect();
return { x: x – bbox.left * (canvas.width / bbox.width),
y: y – bbox.top * (canvas.height / bbox.height)
};
}

function loaded() {
setTimeout( update, 1000/8);
}
function redraw()
{
// var imageObj = document.createElement("img");
// var imageObj = new Image();
var imageObj = images[frame];
ctx.clearRect(0, 0, width, height)
ctx.drawImage(imageObj, 0, 0, width, height);
}
function update() {
redraw();
frame++;
if (frame >= 23) frame = 1;
setTimeout( update, 1000/8);
}
</script>
</head>
<body>
<progress id="loadProgressBar" value="0" max="23"></progress>