biguiyuan/pages/AR/index.js

import {CrsClient} from "./crsClient";
import {CryptoJS} from "./CryptoJS";

const systemInfo = wx.getSystemInfoSync();

const SELECT_TYPE = {
    NONE: 0,
    IMAGE: 1,
    VIDEO: 2,
};
let timer = null

Page({
    data: {
        showtoast: false,
        showOverlay: true,
        showSelect: false,
        SELECT_TYPE: SELECT_TYPE,
        selectType: 0,
        //CRS配置
        config: {
            apiKey: 'a9abd99b2dfb3a5bee964cbb0bced0ae', // EasyAR开发中心 - API KEY - API Key
            apiSecret: '483e000a38265687c058efb7ab66cbc0917a3331b6dbf5482df46c76cb749529',  // EasyAR开发中心 - API KEY - API Secret
            crsAppId: '8911f4b8f03725e300ca4130c01f27e9', // EasyAR开发中心 - 云服务 - 云识别管理 - 云识别库信息 - CRS AppId
            token: '',
            clientHost: 'https://bd9b3490fe845642e600cf53f0cd64b8.cn1.crs.easyar.com:8443', //服务器一般不变
            jpegQuality: 0.7, //JPEG压缩质量，建议不低于70%
            minInterval: 2000, //最短的两次CRS请求间隔
        },
        //识别到这个数组中的ID就触发内容
        targetIds: [
            "6c27e0a1-e4ca-424d-9062-4c8ec676a5ad",
            "ec72a9a2-20d5-4b86-82db-05f29e1c0fbb",
            "f0bdba05-e610-4d1c-811a-5034ccc0d1f7",
            "79014ee9-60c7-4a0c-81ed-0d5889a7ecc9"
        ],
        showLoading: false,
        showLoadingText: "",
    },
    /** @type {CameraFrameListener} 相机帧回调 */
    listener: undefined,
    /** @type {HTMLCanvasElement} canvas对象 */
    canvas: undefined,
    /** @type {boolean} 是否需要持续识别，在点击“识别体验”之后和识别成功之前为true */
    runningCrs: undefined,
    /** @type {boolean} 当前是否正在进行CRS请求 */
    busy: undefined,
    /** @type {CrsClient} 负责发起CRS请求的对象 */
    crsClient: undefined,
    /** @type {number} 最后一次CRS请求的事件，用于判断是否满足最短请求间隔 */
    last: undefined,

    onLoad: function () {
        
        this.daojishi() // 默认进入页面10S后退出
    },
    onReady: function () {
        if (systemInfo.platform === "devtools") { //开发工具不会触发initdone事件，于是在onReady手动触发
            this.onCameraInit();
        }
        // 获取token
        this.queryToken().then(msg => {
            console.log(msg)
            this.data.config.token = msg;
        }).catch(err => {
            console.info(err);
        });
    },
    onHide(){
        this.listener =null
        this.busy=false
        this.runningCrs=false
        clearInterval(timer);
    },
    onUnload: function () {
        this.listener =null
        this.busy=false
        this.runningCrs=false
        clearInterval(timer);
    },
    daojishi: function(){
        let that = this
        let seconds = 10
        timer = setInterval(function(){
          seconds--;
          if(seconds<2){
              that.setData({
                showtoast: true
              })
          }
          if(seconds<=0){
            clearInterval(timer);
            this.listener = null
            wx.navigateBack({
              delta: 1,
            })
          }
        }, 1000)
    },
    showLoading(text) {
        this.setData({
            showLoading: true,
            showLoadingText: text,
        });
    },
    hideLoading() {
        this.setData({
            showLoading: false,
        });
    },
    //图像识别部分：
    onShow: function () {
        if (this.listener) this.listener.start(); //页面隐藏时相机帧的监听会自动停止，但恢复展示时不会自动启动，这里手动启动
        this.scan()
    },
    scan: function () {
        this.runningCrs = true;
        this.setData({
            showOverlay: false,
            showContent: false,
            selectType: SELECT_TYPE.NONE,
        });
        this.showLoading("识别中");
    },
    onCameraInit: function () {
        //找到canvas对象
        const query = wx.createSelectorQuery();
        query.select('#capture')
            .fields({node: true})
            .exec((res) => { 
                const canvas = res[0].node;
                //设置canvas内部尺寸为480*640，frame-size="medium"的设置下相机帧大多是480*640
                canvas.width = 480;
                canvas.height = 640;
                this.canvas = canvas;
                this.crsClient = new CrsClient(this.data.config, this.canvas);
                //开始监听相机帧
                let cameraContext = wx.createCameraContext();
                this.listener = cameraContext.onCameraFrame(frame => {
                    if (!this.canvas) return;
                    let canvas = this.canvas;
                    //如果尺寸不匹配，就修改canvas尺寸以适应相机帧
                    if (canvas.width !== frame.width || canvas.height !== frame.height) {
                        canvas.width = frame.width;
                        canvas.height = frame.height;
                    }
                    this.queryImage(frame);
                });
                this.listener.start();
            });
    },

    queryImage: function (frame) {
        if (!this.runningCrs || this.busy || !this.crsClient) return;
        //最短的两次CRS请求间隔
        let now = new Date().getTime();
        if (this.last && (now - this.last < this.data.config.minInterval)) return;
        this.last = now;
        this.busy = true; //如果正在进行CRS请求，就不允许再次请求
        this.crsClient.queryImage(frame).then(res => {
            if (!this.runningCrs) return; //避免在停止后仍然触发
            let result = res.result;
            if (!result) return;
            if (result.target) {
                console.log("识别成功");
                this.runningCrs = false;
                this.hideLoading();
                let base64 = result.target.meta
                let web = this.base64_decode(base64)
                console.log(web)
                // 解析跳转链接
                wx.navigateTo({
                    url: '/pages/out/index?web=' + web + '&index=2',
                })
                // todo: 解析meta中的信息，触发业务逻辑
                //如果待触发的id列表中存在识别到的这个id，就触发
                if (this.data.targetIds.find(targetId => targetId === result.target.meta)) {
                    this.onResult(result.target.meta);
                }
            } else {
                console.log("识别失败");
            }
            this.busy = false;
        }).catch(e => {
            this.busy = false;
        }); //小程序iOS端不支持finally，所以在then和catch里分别设置busy = false
    },
    onResult: function (target) {
        console.log("触发内容!");
        console.log(target);
        if (target) {
            console.log("meta base64:", target);
        }
        this.setData({
            showOverlay: false,
            showContent: true,
            selectType: SELECT_TYPE.IMAGE,
        });
    },
    //界面：
    back: function () {
        this.runningCrs = false;
        this.setData({
            showOverlay: true,
            showContent: false,
            selectType: SELECT_TYPE.NONE,
        });
        this.hideLoading();
    },
   
    queryToken: function() { // 获取token
        return new Promise((resolve, reject) => {
            wx.request({
                url: getApp().globalData.httpurl +'ar/ar/getToken',
                method: 'get',
                data: {},
                header: {
                    'content-type': 'application/json'
                },
                success: res => resolve(res.data),
                fail: err => reject(err)
            });
        });
    },
    base64_decode(input) { // 解码，配合decodeURIComponent使用
        var base64EncodeChars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";
        var output = "";
        var chr1, chr2, chr3;
        var enc1, enc2, enc3, enc4;
        var i = 0;
        input = input.replace(/[^A-Za-z0-9\+\/\=]/g, "");
        while (i < input.length) {
            enc1 = base64EncodeChars.indexOf(input.charAt(i++));
            enc2 = base64EncodeChars.indexOf(input.charAt(i++));
            enc3 = base64EncodeChars.indexOf(input.charAt(i++));
            enc4 = base64EncodeChars.indexOf(input.charAt(i++));
            chr1 = (enc1 << 2) | (enc2 >> 4);
            chr2 = ((enc2 & 15) << 4) | (enc3 >> 2);
            chr3 = ((enc3 & 3) << 6) | enc4;
            output = output + String.fromCharCode(chr1);
            if (enc3 != 64) {
                output = output + String.fromCharCode(chr2);
            }
            if (enc4 != 64) {
                output = output + String.fromCharCode(chr3);
            }
        }
        return this.utf8_decode(output);
    },
    utf8_decode(utftext) { // utf-8解码
        var string = '';
        let i = 0;
        let c = 0;
        let c1 = 0;
        let c2 = 0;
        while (i < utftext.length) {
            c = utftext.charCodeAt(i);
            if (c < 128) {
                string += String.fromCharCode(c);
                i++;
            } else if ((c > 191) && (c < 224)) {
                c1 = utftext.charCodeAt(i + 1);
                string += String.fromCharCode(((c & 31) << 6) | (c1 & 63));
                i += 2;
            } else {
                c1 = utftext.charCodeAt(i + 1);
                c2 = utftext.charCodeAt(i + 2);
                string += String.fromCharCode(((c & 15) << 12) | ((c1 & 63) << 6) | (c2 & 63));
                i += 3;
            }
        }
        return string;
    }
});