LuaCsForBarotraumaEP/BarotraumaShared/Source/Utils/Rand.cs

using Microsoft.Xna.Framework;
using System;

namespace Barotrauma
{
    static class Rand
    {
        public enum RandSync
        {
            Unsynced = -1, //not synced, used for unimportant details like minor particle properties
            Server = 0, //synced with the server (used for gameplay elements that the players can interact with)
            ClientOnly = 1 //set to match between clients (used for misc elements that the server doesn't track, but clients want to match anyway)
        }

        private static Random localRandom = new Random();
        private static Random[] syncedRandom = new MTRandom[] {
            new MTRandom(), new MTRandom()
        };

        public static void SetSyncedSeed(int seed)
        {
            syncedRandom[(int)RandSync.Server] = new MTRandom(seed);
            syncedRandom[(int)RandSync.ClientOnly] = new MTRandom(seed);
        }
        
        private static void Assert(RandSync sync)
        {
            //TODO: REMOVE AFTER FINDING ALL WRONG RNG USAGE
#if false
            string trace = Environment.StackTrace.ToString();
            if (sync != RandSync.Server) return;
            if (trace.ToLower().Contains("barotraumaclient\\source")) DebugConsole.NewMessage("WARNING: Client code using RandSync.Server\n"+trace,Color.Yellow);
#endif
        }

        public static float Range(float minimum, float maximum, RandSync sync=RandSync.Unsynced)
        {
            Assert(sync);
            return (float)(sync == RandSync.Unsynced ? localRandom : (syncedRandom[(int)sync])).NextDouble() * (maximum - minimum) + minimum;
        }

        public static int Range(int minimum, int maximum, RandSync sync = RandSync.Unsynced)
        {
            Assert(sync);
            return (sync == RandSync.Unsynced ? localRandom : (syncedRandom[(int)sync])).Next(maximum - minimum) + minimum;
        }

        public static int Int(int max, RandSync sync = RandSync.Unsynced)
        {
            Assert(sync);
            return (sync == RandSync.Unsynced ? localRandom : (syncedRandom[(int)sync])).Next(max);
        }

        public static Vector2 Vector(float length, RandSync sync = RandSync.Unsynced)
        {
            Assert(sync);
            Vector2 randomVector = new Vector2(Range(-1.0f, 1.0f, sync), Range(-1.0f, 1.0f, sync));

            if (randomVector == Vector2.Zero) return new Vector2(0.0f, length);

            return Vector2.Normalize(randomVector) * length;
        }

    }
}