1 files changed, 9 insertions, 0 deletions
diff --git a/src/engine/utils/random.ts b/src/engine/utils/random.ts
new file mode 100644
index 0000000..3d9d8b8
--- /dev/null
+++ b/src/engine/utils/random.ts
@@ -0,0 +1,9 @@
+export const normalRandom = (mean: number, stdDev: number, maxStdDevs = 2) => {
+  const [u, v] = [0, 0].map(() => Math.random() + 1e-12);
+  const normal =
+    mean + stdDev * Math.sqrt(-2.0 * Math.log(u)) * Math.cos(2.0 * Math.PI * v);
+  return Math.min(
+    mean + maxStdDevs * stdDev,
+    Math.max(mean - maxStdDevs * stdDev, normal),
+  );
+};