diff options
Diffstat (limited to 'platform/javascript/engine.js')
| -rw-r--r-- | platform/javascript/engine.js | 366 |
1 files changed, 366 insertions, 0 deletions
diff --git a/platform/javascript/engine.js b/platform/javascript/engine.js new file mode 100644 index 0000000000..552f5a7e02 --- /dev/null +++ b/platform/javascript/engine.js @@ -0,0 +1,366 @@ + return Module; + }, +}; + +(function() { + var engine = Engine; + + var USING_WASM = engine.USING_WASM; + var DOWNLOAD_ATTEMPTS_MAX = 4; + + var basePath = null; + var engineLoadPromise = null; + + var loadingFiles = {}; + + function getBasePath(path) { + + if (path.endsWith('/')) + path = path.slice(0, -1); + if (path.lastIndexOf('.') > path.lastIndexOf('/')) + path = path.slice(0, path.lastIndexOf('.')); + return path; + } + + function getBaseName(path) { + + path = getBasePath(path); + return path.slice(path.lastIndexOf('/') + 1); + } + + Engine = function Engine() { + + this.rtenv = null; + + var gameInitPromise = null; + var unloadAfterInit = true; + var memorySize = 268435456; + + var progressFunc = null; + var pckProgressTracker = {}; + var lastProgress = { loaded: 0, total: 0 }; + + var canvas = null; + var stdout = null; + var stderr = null; + + this.initGame = function(mainPack) { + + if (!gameInitPromise) { + + if (mainPack === undefined) { + if (basePath !== null) { + mainPack = basePath + '.pck'; + } else { + return Promise.reject(new Error("No main pack to load specified")); + } + } + if (basePath === null) + basePath = getBasePath(mainPack); + + gameInitPromise = Engine.initEngine().then( + instantiate.bind(this) + ); + var gameLoadPromise = loadPromise(mainPack, pckProgressTracker).then(function(xhr) { return xhr.response; }); + gameInitPromise = Promise.all([gameLoadPromise, gameInitPromise]).then(function(values) { + // resolve with pck + return new Uint8Array(values[0]); + }); + if (unloadAfterInit) + gameInitPromise.then(Engine.unloadEngine); + requestAnimationFrame(animateProgress); + } + return gameInitPromise; + }; + + function instantiate(initializer) { + + var rtenvOpts = { + noInitialRun: true, + thisProgram: getBaseName(basePath), + engine: this, + }; + if (typeof stdout === 'function') + rtenvOpts.print = stdout; + if (typeof stderr === 'function') + rtenvOpts.printErr = stderr; + if (typeof WebAssembly === 'object' && initializer instanceof WebAssembly.Module) { + rtenvOpts.instantiateWasm = function(imports, onSuccess) { + WebAssembly.instantiate(initializer, imports).then(function(result) { + onSuccess(result); + }); + return {}; + }; + } else if (initializer.asm && initializer.mem) { + rtenvOpts.asm = initializer.asm; + rtenvOpts.memoryInitializerRequest = initializer.mem; + rtenvOpts.TOTAL_MEMORY = memorySize; + } else { + throw new Error("Invalid initializer"); + } + + return new Promise(function(resolve, reject) { + rtenvOpts.onRuntimeInitialized = resolve; + rtenvOpts.onAbort = reject; + rtenvOpts.engine.rtenv = Engine.RuntimeEnvironment(rtenvOpts); + }); + } + + this.start = function(mainPack) { + + return this.initGame(mainPack).then(synchronousStart.bind(this)); + }; + + function synchronousStart(pckView) { + // TODO don't expect canvas when runninng as cli tool + if (canvas instanceof HTMLCanvasElement) { + this.rtenv.canvas = canvas; + } else { + var firstCanvas = document.getElementsByTagName('canvas')[0]; + if (firstCanvas instanceof HTMLCanvasElement) { + this.rtenv.canvas = firstCanvas; + } else { + throw new Error("No canvas found"); + } + } + + var actualCanvas = this.rtenv.canvas; + var context = false; + try { + context = actualCanvas.getContext('webgl2') || actualCanvas.getContext('experimental-webgl2'); + } catch (e) {} + if (!context) { + throw new Error("WebGL 2 not available"); + } + + // canvas can grab focus on click + if (actualCanvas.tabIndex < 0) { + actualCanvas.tabIndex = 0; + } + // necessary to calculate cursor coordinates correctly + actualCanvas.style.padding = 0; + actualCanvas.style.borderWidth = 0; + actualCanvas.style.borderStyle = 'none'; + // until context restoration is implemented + actualCanvas.addEventListener('webglcontextlost', function(ev) { + alert("WebGL context lost, please reload the page"); + ev.preventDefault(); + }, false); + + this.rtenv.FS.createDataFile('/', this.rtenv.thisProgram + '.pck', pckView, true, true, true); + gameInitPromise = null; + this.rtenv.callMain(); + } + + this.setProgressFunc = function(func) { + progressFunc = func; + }; + + function animateProgress() { + + var loaded = 0; + var total = 0; + var totalIsValid = true; + var progressIsFinal = true; + + [loadingFiles, pckProgressTracker].forEach(function(tracker) { + Object.keys(tracker).forEach(function(file) { + if (!tracker[file].final) + progressIsFinal = false; + if (!totalIsValid || tracker[file].total === 0) { + totalIsValid = false; + total = 0; + } else { + total += tracker[file].total; + } + loaded += tracker[file].loaded; + }); + }); + if (loaded !== lastProgress.loaded || total !== lastProgress.total) { + lastProgress.loaded = loaded; + lastProgress.total = total; + if (typeof progressFunc === 'function') + progressFunc(loaded, total); + } + if (!progressIsFinal) + requestAnimationFrame(animateProgress); + } + + this.setCanvas = function(elem) { + canvas = elem; + }; + + this.setAsmjsMemorySize = function(size) { + memorySize = size; + }; + + this.setUnloadAfterInit = function(enabled) { + + if (enabled && !unloadAfterInit && gameInitPromise) { + gameInitPromise.then(Engine.unloadEngine); + } + unloadAfterInit = enabled; + }; + + this.setStdoutFunc = function(func) { + + var print = function(text) { + if (arguments.length > 1) { + text = Array.prototype.slice.call(arguments).join(" "); + } + func(text); + }; + if (this.rtenv) + this.rtenv.print = print; + stdout = print; + }; + + this.setStderrFunc = function(func) { + + var printErr = function(text) { + if (arguments.length > 1) + text = Array.prototype.slice.call(arguments).join(" "); + func(text); + }; + if (this.rtenv) + this.rtenv.printErr = printErr; + stderr = printErr; + }; + + + }; // Engine() + + Engine.RuntimeEnvironment = engine.RuntimeEnvironment; + + Engine.initEngine = function(newBasePath) { + + if (newBasePath !== undefined) basePath = getBasePath(newBasePath); + if (engineLoadPromise === null) { + if (USING_WASM) { + if (typeof WebAssembly !== 'object') + return Promise.reject(new Error("Browser doesn't support WebAssembly")); + // TODO cache/retrieve module to/from idb + engineLoadPromise = loadPromise(basePath + '.wasm').then(function(xhr) { + return WebAssembly.compile(xhr.response); + }); + } else { + var asmjsPromise = loadPromise(basePath + '.asm.js').then(function(xhr) { + return asmjsModulePromise(xhr.response); + }); + var memPromise = loadPromise(basePath + '.mem'); + engineLoadPromise = Promise.all([asmjsPromise, memPromise]).then(function(values) { + return { asm: values[0], mem: values[1] }; + }); + } + engineLoadPromise = engineLoadPromise.catch(function(err) { + engineLoadPromise = null; + throw err; + }); + } + return engineLoadPromise; + }; + + function asmjsModulePromise(module) { + var elem = document.createElement('script'); + var script = new Blob([ + 'Engine.asm = (function() { var Module = {};', + module, + 'return Module.asm; })();' + ]); + var url = URL.createObjectURL(script); + elem.src = url; + return new Promise(function(resolve, reject) { + elem.addEventListener('load', function() { + URL.revokeObjectURL(url); + var asm = Engine.asm; + Engine.asm = undefined; + setTimeout(function() { + // delay to reclaim compilation memory + resolve(asm); + }, 1); + }); + elem.addEventListener('error', function() { + URL.revokeObjectURL(url); + reject("asm.js faiilure"); + }); + document.body.appendChild(elem); + }); + } + + Engine.unloadEngine = function() { + engineLoadPromise = null; + }; + + function loadPromise(file, tracker) { + if (tracker === undefined) + tracker = loadingFiles; + return new Promise(function(resolve, reject) { + loadXHR(resolve, reject, file, tracker); + }); + } + + function loadXHR(resolve, reject, file, tracker) { + + var xhr = new XMLHttpRequest; + xhr.open('GET', file); + if (!file.endsWith('.js')) { + xhr.responseType = 'arraybuffer'; + } + ['loadstart', 'progress', 'load', 'error', 'timeout', 'abort'].forEach(function(ev) { + xhr.addEventListener(ev, onXHREvent.bind(xhr, resolve, reject, file, tracker)); + }); + xhr.send(); + } + + function onXHREvent(resolve, reject, file, tracker, ev) { + + if (this.status >= 400) { + + if (this.status < 500 || ++tracker[file].attempts >= DOWNLOAD_ATTEMPTS_MAX) { + reject(new Error("Failed loading file '" + file + "': " + this.statusText)); + this.abort(); + return; + } else { + loadXHR(resolve, reject, file); + } + } + + switch (ev.type) { + case 'loadstart': + if (tracker[file] === undefined) { + tracker[file] = { + total: ev.total, + loaded: ev.loaded, + attempts: 0, + final: false, + }; + } + break; + + case 'progress': + tracker[file].loaded = ev.loaded; + tracker[file].total = ev.total; + break; + + case 'load': + tracker[file].final = true; + resolve(this); + break; + + case 'error': + case 'timeout': + if (++tracker[file].attempts >= DOWNLOAD_ATTEMPTS_MAX) { + tracker[file].final = true; + reject(new Error("Failed loading file '" + file + "'")); + } else { + loadXHR(resolve, reject, file); + } + break; + + case 'abort': + tracker[file].final = true; + reject(new Error("Loading file '" + file + "' was aborted.")); + break; + } + } +})(); |