playcanvas
Version:
Open-source WebGL/WebGPU 3D engine for the web
124 lines (123 loc) • 3.09 kB
JavaScript
const cachedResult = (func) => {
const uninitToken = {};
let result = uninitToken;
return () => {
if (result === uninitToken) {
result = func();
}
return result;
};
};
class Impl {
static modules = {};
// returns true if the running host supports wasm modules (all browsers except IE)
static wasmSupported = cachedResult(() => {
try {
if (typeof WebAssembly === "object" && typeof WebAssembly.instantiate === "function") {
const module = new WebAssembly.Module(Uint8Array.of(0, 97, 115, 109, 1, 0, 0, 0));
if (module instanceof WebAssembly.Module) {
return new WebAssembly.Instance(module) instanceof WebAssembly.Instance;
}
}
} catch (e) {
}
return false;
});
// load a script
static loadScript(url, callback) {
const s = document.createElement("script");
s.setAttribute("src", url);
s.onload = () => {
callback(null);
};
s.onerror = () => {
callback(`Failed to load script='${url}'`);
};
document.body.appendChild(s);
}
// load a wasm module
static loadWasm(moduleName, config, callback) {
const loadUrl = Impl.wasmSupported() && config.glueUrl && config.wasmUrl ? config.glueUrl : config.fallbackUrl;
if (loadUrl) {
Impl.loadScript(loadUrl, (err) => {
if (err) {
callback(err, null);
} else {
const module = window[moduleName];
window[moduleName] = void 0;
module({
locateFile: () => config.wasmUrl,
onAbort: () => {
callback("wasm module aborted.");
}
}).then((instance) => {
callback(null, instance);
});
}
});
} else {
callback("No supported wasm modules found.", null);
}
}
// get state object for the named module
static getModule(name) {
if (!Impl.modules.hasOwnProperty(name)) {
Impl.modules[name] = {
config: null,
initializing: false,
instance: null,
callbacks: []
};
}
return Impl.modules[name];
}
static initialize(moduleName, module) {
if (module.initializing) {
return;
}
const config = module.config;
if (config.glueUrl || config.wasmUrl || config.fallbackUrl) {
module.initializing = true;
Impl.loadWasm(moduleName, config, (err, instance) => {
if (err) {
if (config.errorHandler) {
config.errorHandler(err);
} else {
console.error(`failed to initialize module=${moduleName} error=${err}`);
}
} else {
module.instance = instance;
module.callbacks.forEach((callback) => {
callback(instance);
});
}
});
}
}
}
class WasmModule {
static setConfig(moduleName, config) {
const module = Impl.getModule(moduleName);
module.config = config;
if (module.callbacks.length > 0) {
Impl.initialize(moduleName, module);
}
}
static getConfig(moduleName) {
return Impl.modules?.[moduleName]?.config;
}
static getInstance(moduleName, callback) {
const module = Impl.getModule(moduleName);
if (module.instance) {
callback(module.instance);
} else {
module.callbacks.push(callback);
if (module.config) {
Impl.initialize(moduleName, module);
}
}
}
}
export {
WasmModule
};