split user.fns

common/script/fns/predictableRandom.js

@@ -0,0 +1,20 @@
+import _ from 'lodash';
+/*
+Because the same op needs to be performed on the client and the server (critical hits, item drops, etc),
+we need things to be "random", but technically predictable so that they don't go out-of-sync
+ */
+
+module.exports = function(user, seed) {
+  var x;
+  if (!seed || seed === Math.PI) {
+    seed = _.reduce(user.stats, (function(m, v) {
+      if (_.isNumber(v)) {
+        return m + v;
+      } else {
+        return m;
+      }
+    }), 0);
+  }
+  x = Math.sin(seed++) * 10000;
+  return x - Math.floor(x);
+};