Choose WebAssembly or asm.js at runtime

dragonruby-html5-loader-little-piece.js

var hasWebAssembly = false;
if (typeof WebAssembly==="object" && typeof WebAssembly.Memory==="function") {
  hasWebAssembly = true;
}
//console.log("Do we have WebAssembly? " + ((hasWebAssembly) ? "YES" : "NO"));

var buildtype = hasWebAssembly ? "wasm" : "asmjs";
var module = "dragonruby-" + buildtype + ".js";

//console.log("Our main module is: " + module);

var script = document.createElement('script');
script.src = module;
if (hasWebAssembly) {
  script.async = true;
} else {
  script.async = false;  // !!! FIXME: can this be async?
  (function() {
    var memoryInitializer = module + '.mem';
    if (typeof Module['locateFile'] === 'function') {
      memoryInitializer = Module['locateFile'](memoryInitializer);
    } else if (Module['memoryInitializerPrefixURL']) {
      memoryInitializer = Module['memoryInitializerPrefixURL'] + memoryInitializer;
    }
    var meminitXHR = Module['memoryInitializerRequest'] = new XMLHttpRequest();
    meminitXHR.open('GET', memoryInitializer, true);
    meminitXHR.responseType = 'arraybuffer';
    meminitXHR.send(null);
  })();
}
document.body.appendChild(script);