three.js/manual/examples/resources/lessons-worker-helper.js

/*
 * Copyright 2019, Gregg Tavares.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 *     * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above
 * copyright notice, this list of conditions and the following disclaimer
 * in the documentation and/or other materials provided with the
 * distribution.
 *     * Neither the name of Gregg Tavares. nor the names of his
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/* global */

'use strict';  // eslint-disable-line

( function () {

	const lessonSettings = self.lessonSettings || {};

	function isInEditor() {

		return self.location.href.substring( 0, 4 ) === 'blob';

	}

	function sendMessage( data ) {

		self.postMessage( {
			type: '__editor__',
			data,
		} );

	}

	const origConsole = {};

	function setupConsole() {

		function wrapFunc( obj, logType ) {

			const origFunc = obj[ logType ].bind( obj );
			origConsole[ logType ] = origFunc;
			return function ( ...args ) {

				origFunc( ...args );
				sendMessage( {
					type: 'log',
					logType,
					msg: [ ...args ].join( ' ' ),
				} );

			};

		}

		self.console.log = wrapFunc( self.console, 'log' );
		self.console.warn = wrapFunc( self.console, 'warn' );
		self.console.error = wrapFunc( self.console, 'error' );

	}

	/**
   * Gets a WebGL context.
   * makes its backing store the size it is displayed.
   * @param {OffscreenCanvas} canvas a canvas element.
   * @memberOf module:webgl-utils
   */
	let setupLesson = function ( canvas ) {

		// only once
		setupLesson = function () {};

		if ( canvas ) {

			canvas.addEventListener( 'webglcontextlost', function () {

				// the default is to do nothing. Preventing the default
				// means allowing context to be restored
				// e.preventDefault();  // can't do this because firefox bug - https://bugzilla.mozilla.org/show_bug.cgi?id=1633280
				sendMessage( {
					type: 'lostContext',
				} );

			} );

		}

	};

	function captureJSErrors() {

		// capture JavaScript Errors
		self.addEventListener( 'error', function ( e ) {

			const msg = e.message || e.error;
			const url = e.filename;
			const lineNo = e.lineno || 1;
			const colNo = e.colno || 1;
			sendMessage( {
				type: 'jsError',
				lineNo,
				colNo,
				url,
				msg,
			} );

		} );

	}


	const isWebGLRE = /^(webgl|webgl2|experimental-webgl)$/i;
	function installWebGLLessonSetup() {

		OffscreenCanvas.prototype.getContext = ( function ( oldFn ) { // eslint-disable-line compat/compat

			return function () {

				const type = arguments[ 0 ];
				const isWebGL = isWebGLRE.test( type );
				if ( isWebGL ) {

					setupLesson( this );

				}

				const args = [].slice.apply( arguments );
				args[ 1 ] = {
					powerPreference: 'low-power',
					...args[ 1 ],
				};
				return oldFn.apply( this, args );

			};

		}( OffscreenCanvas.prototype.getContext ) ); // eslint-disable-line compat/compat

	}

	function installWebGLDebugContextCreator() {

		if ( ! self.webglDebugHelper ) {

			return;

		}

		const {
			makeDebugContext,
			glFunctionArgToString,
			glEnumToString,
		} = self.webglDebugHelper;

		// capture GL errors
		OffscreenCanvas.prototype.getContext = ( function ( oldFn ) { // eslint-disable-line compat/compat

			return function () {

				let ctx = oldFn.apply( this, arguments );
				// Using bindTexture to see if it's WebGL. Could check for instanceof WebGLRenderingContext
				// but that might fail if wrapped by debugging extension
				if ( ctx && ctx.bindTexture ) {

					ctx = makeDebugContext( ctx, {
						maxDrawCalls: 100,
						errorFunc: function ( err, funcName, args ) {

							const numArgs = args.length;
							const enumedArgs = [].map.call( args, function ( arg, ndx ) {

								let str = glFunctionArgToString( funcName, numArgs, ndx, arg );
								// shorten because of long arrays
								if ( str.length > 200 ) {

									str = str.substring( 0, 200 ) + '...';

								}

								return str;

							} );

							{

								const error = new Error();
								sendMessage( {
									type: 'jsErrorWithStack',
									stack: error.stack,
									msg: `${glEnumToString( err )} in ${funcName}(${enumedArgs.join( ', ' )})`,
								} );

							}

						},
					} );

				}

				return ctx;

			};

		}( OffscreenCanvas.prototype.getContext ) ); // eslint-disable-line compat/compat

	}

	installWebGLLessonSetup();

	if ( isInEditor() ) {

		setupConsole();
		captureJSErrors();
		if ( lessonSettings.glDebug !== false ) {

			installWebGLDebugContextCreator();

		}

	}

}() );