forked from mapbox/mapbox-gl-supported
-
Notifications
You must be signed in to change notification settings - Fork 0
/
index.js
175 lines (150 loc) · 5.37 KB
/
index.js
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
'use strict';
if (typeof module !== 'undefined' && module.exports) {
module.exports = isSupported;
} else if (window) {
window.mapboxgl = window.mapboxgl || {};
window.mapboxgl.supported = isSupported;
window.mapboxgl.notSupportedReason = notSupportedReason;
}
/**
* Test whether the current browser supports Mapbox GL JS
* @param {Object} options
* @param {boolean} [options.failIfMajorPerformanceCaveat=false] Return `false`
* if the performance of Mapbox GL JS would be dramatically worse than
* expected (i.e. a software renderer is would be used)
* @return {boolean}
*/
function isSupported(options) {
return !notSupportedReason(options);
}
function notSupportedReason(options) {
if (!isBrowser()) return 'not a browser';
if (!isArraySupported()) return 'insufficent Array support';
if (!isFunctionSupported()) return 'insufficient Function support';
if (!isObjectSupported()) return 'insufficient Object support';
if (!isJSONSupported()) return 'insufficient JSON support';
if (!isWorkerSupported()) return 'insufficient worker support';
if (!isUint8ClampedArraySupported()) return 'insufficient Uint8ClampedArray support';
if (!isArrayBufferSupported()) return 'insufficient ArrayBuffer support';
if (!isCanvasGetImageDataSupported()) return 'insufficient Canvas/getImageData support';
if (!isWebGLSupportedCached(options && options.failIfMajorPerformanceCaveat)) return 'insufficient WebGL support';
}
function isBrowser() {
return typeof window !== 'undefined' && typeof document !== 'undefined';
}
function isArraySupported() {
return (
Array.prototype &&
Array.prototype.every &&
Array.prototype.filter &&
Array.prototype.forEach &&
Array.prototype.indexOf &&
Array.prototype.lastIndexOf &&
Array.prototype.map &&
Array.prototype.some &&
Array.prototype.reduce &&
Array.prototype.reduceRight &&
Array.isArray
);
}
function isFunctionSupported() {
return Function.prototype && Function.prototype.bind;
}
function isObjectSupported() {
return (
Object.keys &&
Object.create &&
Object.getPrototypeOf &&
Object.getOwnPropertyNames &&
Object.isSealed &&
Object.isFrozen &&
Object.isExtensible &&
Object.getOwnPropertyDescriptor &&
Object.defineProperty &&
Object.defineProperties &&
Object.seal &&
Object.freeze &&
Object.preventExtensions
);
}
function isJSONSupported() {
return 'JSON' in window && 'parse' in JSON && 'stringify' in JSON;
}
function isWorkerSupported() {
if (!('Worker' in window && 'Blob' in window && 'URL' in window)) {
return false;
}
var blob = new Blob([''], { type: 'text/javascript' });
var workerURL = URL.createObjectURL(blob);
var supported;
var worker;
try {
worker = new Worker(workerURL);
supported = true;
} catch (e) {
supported = false;
}
if (worker) {
worker.terminate();
}
URL.revokeObjectURL(workerURL);
return supported;
}
// IE11 only supports `Uint8ClampedArray` as of version
// [KB2929437](https://support.microsoft.com/en-us/kb/2929437)
function isUint8ClampedArraySupported() {
return 'Uint8ClampedArray' in window;
}
// https://github.com/mapbox/mapbox-gl-supported/issues/19
function isArrayBufferSupported() {
return ArrayBuffer.isView;
}
// Some browsers or browser extensions block access to canvas data to prevent fingerprinting.
// Mapbox GL uses this API to load sprites and images in general.
function isCanvasGetImageDataSupported() {
const canvas = document.createElement('canvas');
canvas.width = canvas.height = 1;
const context = canvas.getContext('2d');
if (!context) {
return false;
}
const imageData = context.getImageData(0, 0, 1, 1);
return imageData && imageData.width === canvas.width;
}
var isWebGLSupportedCache = {};
function isWebGLSupportedCached(failIfMajorPerformanceCaveat) {
if (isWebGLSupportedCache[failIfMajorPerformanceCaveat] === undefined) {
isWebGLSupportedCache[failIfMajorPerformanceCaveat] = isWebGLSupported(failIfMajorPerformanceCaveat);
}
return isWebGLSupportedCache[failIfMajorPerformanceCaveat];
}
isSupported.webGLContextAttributes = {
antialias: false,
alpha: true,
stencil: true,
depth: true
};
function getWebGLContext(failIfMajorPerformanceCaveat) {
var canvas = document.createElement('canvas');
var attributes = Object.create(isSupported.webGLContextAttributes);
attributes.failIfMajorPerformanceCaveat = failIfMajorPerformanceCaveat;
return (
canvas.getContext('webgl', attributes) ||
canvas.getContext('experimental-webgl', attributes)
);
}
function isWebGLSupported(failIfMajorPerformanceCaveat) {
const gl = getWebGLContext(failIfMajorPerformanceCaveat);
if (!gl) {
return false;
}
// Try compiling a shader and get its compile status. Some browsers like Brave block this API
// to prevent fingerprinting. Unfortunately, this also means that Mapbox GL won't work.
const shader = gl.createShader(gl.VERTEX_SHADER);
if (!shader || gl.isContextLost()) {
return false;
}
gl.shaderSource(shader, 'void main() {}');
gl.compileShader(shader);
return gl.getShaderParameter(shader, gl.COMPILE_STATUS) === true;
}