Only call onload once.

Author: ricmoo

index.html

@@ -144,6 +144,7 @@
             var fireflyField = new FireflyField(document.getElementById('firefly-field'));
 
             ready(function() {
+                fireflyField.resize(window.innerWidth, window.innerHeight);
                 fireflyField.start();
             });
 

scripts/utils.js

@@ -1,8 +1,14 @@
 function ready(fn) {
+    var done = false;
+    function func() {
+        if (done) { return; }
+        done = false;
+        setTimeout(fn, 0);
+    }
     if (document.readyState != 'loading') {
-        fn();
+        func();
     } else {
-        document.addEventListener('DOMContentLoaded', fn);
+        document.addEventListener('DOMContentLoaded', func);
     }
 }