godot/platform/javascript/engine.js
Leon Krause 4db801aaea HTML5 start-up overhaul
- Implement promise-based JS interface for custom HTML page
   integration
 - Add download progress callback
 - Add progress bar and indeterminate spinner to default HTML page
 - Try downloading files multiple times when failing
 - Get rid of godotfs.js
 - Separate steps for engine initialization, game initialization and game
   start
 - Allow multiple games on one HTML page
 - Substitution placeholders only used in .html file
 - Placeholders renamed: $GODOT_BASE => $GODOT_BASENAME,
   $GODOT_TMEM -> $GODOT_TOTAL_MEMORY
 - Emscripten Module is now Engine.RuntimeEnvironment (no longer a global)
2017-09-11 20:56:29 +02:00

367 lines
9.2 KiB
JavaScript

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;
}
}
})();