multiBalls refactoring with ballsArr[]

src/shared_js/utils.ts

@@ -7,4 +7,13 @@ function sleep (ms: number) {
 	return new Promise((resolve) => setTimeout(resolve, ms));
 }
 
-export {random, sleep}
+function clamp(n: number, min: number, max: number) : number
+{
+	if (n < min)
+		n = min;
+	else if (n > max)
+		n = max;
+	return (n);
+}
+
+export {random, sleep, clamp}