https://website.didiglobal.com/static/threejs/Detector.js

1/**
2 * @author alteredq / http://alteredqualia.com/
3 * @author mr.doob / http://mrdoob.com/
4 */
5
6var Detector = {
7
8    canvas: !! window.CanvasRenderingContext2D,
9    webgl: ( function () {
10
11        try {
12
13            var canvas = document.createElement( 'canvas' ); return !! ( window.WebGLRenderingContext && ( canvas.getContext( 'webgl' ) || canvas.getContext( 'experimental-webgl' ) ) );
14
15        } catch ( e ) {
16
17            return false;
18
19        }
20
21    } )(),
22    workers: !! window.Worker,
23    fileapi: window.File && window.FileReader && window.FileList && window.Blob,
24
25    getWebGLErrorMessage: function () {
26
27        var element = document.createElement( 'div' );
28        element.id = 'webgl-error-message';
29        element.style.fontFamily = 'monospace';
30        element.style.fontSize = '13px';
31        element.style.fontWeight = 'normal';
32        element.style.textAlign = 'center';
33        element.style.background = '#fff';
34        element.style.color = '#000';
35        element.style.padding = '1.5em';
36        element.style.width = '400px';
37        element.style.margin = '5em auto 0';
38
39        if ( ! this.webgl ) {
40
41            element.innerHTML = window.WebGLRenderingContext ? [
42                'Your graphics card does not seem to support <a href="http://khronos.org/webgl/wiki/Getting_a_WebGL_Implementation" style="color:#000">WebGL</a>.<br />',
43                'Find out how to get it <a href="http://get.webgl.org/" style="color:#000">here</a>.'
44            ].join( '\n' ) : [
45                'Your browser does not seem to support <a href="http://khronos.org/webgl/wiki/Getting_a_WebGL_Implementation" style="color:#000">WebGL</a>.<br/>',
46                'Find out how to get it <a href="http://get.webgl.org/" style="color:#000">here</a>.'
47            ].join( '\n' );
48
49        }
50
51        return element;
52
53    },
54
55    addGetWebGLMessage: function ( parameters ) {
56
57        var parent, id, element;
58
59        parameters = parameters || {};
60
61        parent = parameters.parent !== undefined ? parameters.parent : document.body;
62        id = parameters.id !== undefined ? parameters.id : 'oldie';
63
64        element = Detector.getWebGLErrorMessage();
65        element.id = id;
66
67        parent.appendChild( element );
68
69    }
70
71};
72
73// browserify support
74if ( typeof module === 'object' ) {
75
76    module.exports = Detector;
77
78}