page.js

if ( ! window.frameElement && window.location.protocol !== 'file:' ) {

	// navigates to docs home if direct access, e.g.
	//   https://mrdoob.github.io/three.js/docs/api/en/audio/Audio.html#filter
	// ->https://mrdoob.github.io/three.js/docs/#api/en/audio/Audio.filter

	const url = new URL( window.location.href );

	// hash route, e.g. #api/en/audio/Audio.filter
	url.hash = url.pathname.replace( /\/docs\/(.*?)(?:\.html)?$/, '$1' ) + url.hash.replace( '#', '.' );

	// docs home, e.g. https://mrdoob.github.io/three.js/docs/
	url.pathname = url.pathname.replace( /(\/docs\/).*$/, '$1' );

	window.location.replace( url );

} else {

	document.addEventListener( 'DOMContentLoaded', onDocumentLoad, { once: true } );

}


function onDocumentLoad() {

	let path, localizedPath;
	const pathname = window.location.pathname;
	const section = /\/(manual|api|examples)\//.exec( pathname )[ 1 ].toString().split( '.html' )[ 0 ];
	let name = /[\-A-Za-z0-9]+\.html/.exec( pathname ).toString().split( '.html' )[ 0 ];

	switch ( section ) {

		case 'api':
			localizedPath = /\/api\/[A-Za-z0-9\/]+/.exec( pathname ).toString().slice( 5 );

			// Remove localized part of the path (e.g. 'en/' or 'es-MX/'):
			path = localizedPath.replace( /^[A-Za-z0-9-]+\//, '' );

			break;

		case 'examples':
			path = localizedPath = /\/examples\/[A-Za-z0-9\/]+/.exec( pathname ).toString().slice( 10 );
			break;

		case 'manual':
			name = name.replace( /\-/g, ' ' );

			path = pathname.replace( /\ /g, '-' );
			path = localizedPath = /\/manual\/[-A-Za-z0-9\/]+/.exec( path ).toString().slice( 8 );
			break;

	}

	let text = document.body.innerHTML;

	text = text.replace( /\[name\]/gi, name );
	text = text.replace( /\[path\]/gi, path );
	text = text.replace( /\[page:([\w\.]+)\]/gi, '[page:$1 $1]' ); // [page:name] to [page:name title]
	text = text.replace( /\[page:\.([\w\.]+) ([\w\.\s]+)\]/gi, `[page:${name}.$1 $2]` ); // [page:.member title] to [page:name.member title]
	text = text.replace( /\[page:([\w\.]+) ([\w\.\s]+)\]/gi, '<a class=\'links\' data-fragment=\'$1\' title=\'$1\'>$2</a>' ); // [page:name title]
	// text = text.replace( /\[member:.([\w]+) ([\w\.\s]+)\]/gi, "<a onclick=\"window.parent.setUrlFragment('" + name + ".$1')\" title=\"$1\">$2</a>" );

	text = text.replace( /\[(member|property|method|param):([\w]+)\]/gi, '[$1:$2 $2]' ); // [member:name] to [member:name title]
	text = text.replace( /\[(?:member|property|method):([\w]+) ([\w\.\s]+)\]\s*(\([\s\S]*?\))?/gi, `<a class='permalink links' data-fragment='${name}.$2' target='_parent' title='${name}.$2'>#</a> .<a class='links' data-fragment='${name}.$2' id='$2'>$2</a> $3 : <a class='param links' data-fragment='$1'>$1</a>` );
	text = text.replace( /\[param:([\w\.]+) ([\w\.\s]+)\]/gi, '$2 : <a class=\'param links\' data-fragment=\'$1\'>$1</a>' ); // [param:name title]

	text = text.replace( /\[link:([\w\:\/\.\-\_\(\)\?\#\=\!\~]+)\]/gi, '<a href="$1" target="_blank">$1</a>' ); // [link:url]
	text = text.replace( /\[link:([\w:/.\-_()?#=!~]+) ([\w\p{L}:/.\-_'\s]+)\]/giu, '<a href="$1" target="_blank">$2</a>' ); // [link:url title]
	text = text.replace( /\*([\u4e00-\u9fa5\w\d\-\(\"\（\“][\u4e00-\u9fa5\w\d\ \/\+\-\(\)\=\,\.\（\）\，\。"]*[\u4e00-\u9fa5\w\d\"\)\”\）]|\w)\*/gi, '<strong>$1</strong>' ); // *text*
	text = text.replace( /\`(.*?)\`/gs, '<code class="inline">$1</code>' ); // `code`

	text = text.replace( /\[example:([\w\_]+)\]/gi, '[example:$1 $1]' ); // [example:name] to [example:name title]
	text = text.replace( /\[example:([\w\_]+) ([\w\:\/\.\-\_ \s]+)\]/gi, '<a href="../examples/#$1" target="_blank">$2</a>' ); // [example:name title]

	text = text.replace( /<a class=\'param links\' data-fragment=\'\w+\'>(undefined|null|this|Boolean|Object|Array|Number|String|Integer|Float|TypedArray|ArrayBuffer)<\/a>/gi, '<span class="param">$1</span>' ); // remove links to primitive types

	document.body.innerHTML = text;

	if ( window.parent.getPageURL ) {

		const links = document.querySelectorAll( '.links' );
		for ( let i = 0; i < links.length; i ++ ) {

			const pageURL = window.parent.getPageURL( links[ i ].dataset.fragment );
			if ( pageURL ) {

				links[ i ].href = './index.html#' + pageURL;

			}

		}

	}

	document.body.addEventListener( 'click', event => {

		const element = event.target;
		if ( element.classList.contains( 'links' ) && event.button === 0 && ! event.shiftKey && ! event.ctrlKey && ! event.metaKey && ! event.altKey ) {

			window.parent.setUrlFragment( element.dataset.fragment );
			event.preventDefault();

		}

	} );

	// handle code snippets formatting

	function dedent( text ) {

		// ignores singleline text
		const lines = text.split( '\n' );
		if ( lines.length <= 1 ) return text;

		// ignores blank text
		const nonBlankLine = lines.filter( l => l.trim() )[ 0 ];
		if ( nonBlankLine === undefined ) return text;

		// strips indents if any
		const m = nonBlankLine.match( /^([\t ]+)/ );
		if ( m ) text = lines.map( l => l.startsWith( m[ 1 ] ) ? l.substring( m[ 1 ].length ) : l ).join( '\n' );

		// strips leading and trailing whitespaces finally
		return text.trim();

	}

	// create copy button for copying code snippets

	function addCopyButton( element ) {

		const copyButton = document.createElement( 'button' );
		copyButton.className = 'copy-btn';

		element.appendChild( copyButton );

		copyButton.addEventListener( 'click', function () {

			const codeContent = element.textContent;
			navigator.clipboard.writeText( codeContent ).then( () => {

				copyButton.classList.add( 'copied' );

				setTimeout( () => {

					copyButton.classList.remove( 'copied' );

				}, 1000 );

			} );

		} );

	}

	const elements = document.getElementsByTagName( 'code' );

	for ( let i = 0; i < elements.length; i ++ ) {

		const element = elements[ i ];

		element.textContent = dedent( element.textContent );

		if ( ! element.classList.contains( 'inline' ) ) {

			addCopyButton( element );

		}

	}

	// Edit button

	const button = document.createElement( 'div' );
	button.id = 'button';
	button.innerHTML = '<img src="../files/ic_mode_edit_black_24dp.svg">';
	button.addEventListener( 'click', function () {

		window.open( 'https://github.com/mrdoob/three.js/blob/dev/docs/' + section + '/' + localizedPath + '.html' );

	}, false );

	document.body.appendChild( button );

	// Syntax highlighting

	const styleBase = document.createElement( 'link' );
	styleBase.href = pathname.substring( 0, pathname.indexOf( 'docs' ) + 4 ) + '/prettify/prettify.css';
	styleBase.rel = 'stylesheet';

	const styleCustom = document.createElement( 'link' );
	styleCustom.href = pathname.substring( 0, pathname.indexOf( 'docs' ) + 4 ) + '/prettify/threejs.css';
	styleCustom.rel = 'stylesheet';

	document.head.appendChild( styleBase );
	document.head.appendChild( styleCustom );

	const prettify = document.createElement( 'script' );
	prettify.src = pathname.substring( 0, pathname.indexOf( 'docs' ) + 4 ) + '/prettify/prettify.js';

	prettify.onload = function () {

		const elements = document.getElementsByTagName( 'code' );

		for ( let i = 0; i < elements.length; i ++ ) {

			const e = elements[ i ];
			e.currentStyle = { 'whiteSpace': 'pre-wrap' }; // Workaround for Firefox, see #30008
			e.className += ' prettyprint';
			e.setAttribute( 'translate', 'no' );

		}

	};

	document.head.appendChild( prettify );

}