virtualx-engine/platform/web/js/engine/features.js

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const Features = { // eslint-disable-line no-unused-vars
/**
* Check whether WebGL is available. Optionally, specify a particular version of WebGL to check for.
*
* @param {number=} [majorVersion=1] The major WebGL version to check for.
* @returns {boolean} If the given major version of WebGL is available.
* @function Engine.isWebGLAvailable
*/
isWebGLAvailable: function (majorVersion = 1) {
try {
return !!document.createElement('canvas').getContext(['webgl', 'webgl2'][majorVersion - 1]);
} catch (e) { /* Not available */ }
return false;
},
/**
* Check whether the Fetch API available and supports streaming responses.
*
* @returns {boolean} If the Fetch API is available and supports streaming responses.
* @function Engine.isFetchAvailable
*/
isFetchAvailable: function () {
return 'fetch' in window && 'Response' in window && 'body' in window.Response.prototype;
},
/**
* Check whether the engine is running in a Secure Context.
*
* @returns {boolean} If the engine is running in a Secure Context.
* @function Engine.isSecureContext
*/
isSecureContext: function () {
return window['isSecureContext'] === true;
},
/**
* Check whether the engine is cross origin isolated.
* This value is dependent on Cross-Origin-Opener-Policy and Cross-Origin-Embedder-Policy headers sent by the server.
*
* @returns {boolean} If the engine is running in a Secure Context.
* @function Engine.isSecureContext
*/
isCrossOriginIsolated: function () {
return window['crossOriginIsolated'] === true;
},
/**
* Check whether SharedBufferArray is available.
*
* Most browsers require the page to be running in a secure context, and the
* the server to provide specific CORS headers for SharedArrayBuffer to be available.
*
* @returns {boolean} If SharedArrayBuffer is available.
* @function Engine.isSharedArrayBufferAvailable
*/
isSharedArrayBufferAvailable: function () {
return 'SharedArrayBuffer' in window;
},
/**
* Check whether the AudioContext supports AudioWorkletNodes.
*
* @returns {boolean} If AudioWorkletNode is available.
* @function Engine.isAudioWorkletAvailable
*/
isAudioWorkletAvailable: function () {
return 'AudioContext' in window && 'audioWorklet' in AudioContext.prototype;
},
/**
* Return an array of missing required features (as string).
*
* @returns {Array<string>} A list of human-readable missing features.
* @function Engine.getMissingFeatures
*/
getMissingFeatures: function () {
const missing = [];
if (!Features.isWebGLAvailable(2)) {
missing.push('WebGL2');
}
if (!Features.isFetchAvailable()) {
missing.push('Fetch');
}
if (!Features.isSecureContext()) {
missing.push('Secure Context');
}
if (!Features.isCrossOriginIsolated()) {
missing.push('Cross Origin Isolation');
}
if (!Features.isSharedArrayBufferAvailable()) {
missing.push('SharedArrayBuffer');
}
// Audio is normally optional since we have a dummy fallback.
return missing;
},
};