rng class..

common/Rng.js

@@ -0,0 +1,27 @@
+export class Rng {
+  constructor(seed) {
+    this.rand_high = seed || 0xDEADC0DE
+    this.rand_low = seed ^ 0x49616E42
+  }
+
+  random (min, max) {
+    this.rand_high = ((this.rand_high << 16) + (this.rand_high >> 16) + this.rand_low) & 0xffffffff;
+    this.rand_low = (this.rand_low + this.rand_high) & 0xffffffff;
+    var n = (this.rand_high >>> 0) / 0xffffffff;
+    return (min + n * (max-min+1))|0;
+  }
+
+  static serialize (rng) {
+    return {
+      rand_high: rng.rand_high,
+      rand_low: rng.rand_low
+    }
+  }
+
+  static unserialize (rngSerialized) {
+    const rng = new Rng(0)
+    rng.rand_high = rngSerialized.rand_high
+    rng.rand_low = rngSerialized.rand_low
+    return rng
+  }
+}