标签:android style blog http io ar os sp java
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://www.voidcanvas.com/demo/28823deye/
自己玩了玩这个Demo以后,照着它的思路,用HTML5 Canvas也实现了类似的功能。
所以先说一下它的360度全景图的原理
1. 首先需要对实物拍照,间隔是每张照片旋转15度,所以需要23张照片。
2. 照片准备好了以后,尽量选择JPG格式,裁剪到适当大小。
3. JAVASCRIPT中预加载所有照片,可以配合进度条显示加载精度
4. 创建/获取Canvas对象,加上鼠标监听事件,当鼠标左右移动时候,适度的绘制不
同帧。大致的原理就是这样,简单吧
实现代码:
demo:下载地址:http://pan.baidu.com/s/1bnhbJaB
- <!DOCTYPE html>
- <html>
- <head>
- <meta charset=utf-8">
- <title>Full 360 degree View</title>
- <script>
- var ctx = null; // global variable 2d context
- var frame = 1; // 23
- var width = 0;
- var height = 0;
- var started = false;
- var images = new Array();
- var startedX = -1;
- window.onload = function() {
- var canvas = document.getElementById("fullview_canvas");
- canvas.width = 440;// window.innerWidth;
- canvas.height = 691;//window.innerHeight;
- width = canvas.width;
- height = canvas.height;
- var bar = document.getElementById(‘loadProgressBar‘);
- for(var i=1; i<24; i++)
- {
- bar.value = i;
- if(i<10)
- {
- images[i] = new Image();
- images[i].src = "0" + i + ".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>
- <canvas id="fullview_canvas"></canvas>
- <button onclick="loaded()">Auto Play</button>
- </body>
- </html>
360实物全景图像 摘抄
标签:android style blog http io ar os sp java
原文地址:http://www.cnblogs.com/cmzcheng/p/4120794.html