Ticket #4127: init_simulation_seed_v1.patch

binaries/data/mods/public/gui/gamesetup/gamesetup.js

@@ -1280 +1280 @@
         let player = g_PlayerAssignments[guid];
         if (player.player > 0)  // not observer or GAIA
             g_GameAttributes.settings.PlayerData[player.player - 1].Name = player.name;
     }
 
-    // This seed is only used for map-generation
-    if (g_GameAttributes.mapType == "random")
-        g_GameAttributes.settings.Seed = Math.floor(Math.random() * 65536);
-
-    g_GameAttributes.settings.AISeed = Math.floor(Math.random() * 65536);
+    // Seed used for both map generation and simulation
+    g_GameAttributes.settings.Seed = Math.floor(Math.random() * Math.pow(2, 32));
+    g_GameAttributes.settings.AISeed = Math.floor(Math.random() * Math.pow(2, 32));
 
     // Used for identifying rated game reports for the lobby
     g_GameAttributes.matchID = Engine.GetMatchID();
 
     if (g_IsNetworked)

source/simulation2/Simulation2.cpp

@@ -759 +759 @@
 }
 
 void CSimulation2::SetMapSettings(JS::HandleValue settings)
 {
     m->m_MapSettings = settings;
+
+    u32 seed = 0;
+    if (!m->m_ComponentManager.GetScriptInterface().GetProperty(m->m_MapSettings, "Seed", seed))
+        LOGWARNING("CSimulation2::SetInitAttributes: No seed value specified - using %d", seed);
+
+    m->m_ComponentManager.SetRNGSeed(seed);
 }
 
 std::string CSimulation2::GetMapSettingsString()
 {
     return m->m_ComponentManager.GetScriptInterface().StringifyJSON(&m->m_MapSettings);

source/simulation2/Simulation2.h

@@ -106 +106 @@
     void GetInitAttributes(JS::MutableHandleValue ret);
 
     /**
      * Set the initial map settings (as a UTF-8-encoded JSON string),
      * which will be used to set up the simulation state.
+     * Called from atlas.
      */
     void SetMapSettings(const std::string& settings);
 
     /**
      * Set the initial map settings, which will be used
      * to set up the simulation state.
+     * Called from MapReader (for all map-types).
      */
     void SetMapSettings(JS::HandleValue settings);
 
     /**
      * Get the current map settings as a UTF-8 JSON string.
@@ -266 +268 @@
      */
     std::string GetAIData();
 
 private:
     CSimulation2Impl* m;
+
 };
 
 #endif // INCLUDED_SIMULATION2

source/simulation2/system/ComponentManager.cpp

@@ -1 @@
-/* Copyright (C) 2015 Wildfire Games.
+/* Copyright (C) 2016 Wildfire Games.
  * This file is part of 0 A.D.
  *
  * 0 A.D. is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation, either version 2 of the License, or
@@ -59 +59 @@
     m_SimContext(context), m_CurrentlyHotloading(false)
 {
     context.SetComponentManager(this);
 
     m_ScriptInterface.SetCallbackData(static_cast<void*> (this));
-
-    // TODO: ought to seed the RNG (in a network-synchronised way) before we use it
     m_ScriptInterface.ReplaceNondeterministicRNG(m_RNG);
     m_ScriptInterface.LoadGlobalScripts();
 
     // For component script tests, the test system sets up its own scripted implementation of
     // these functions, so we skip registering them here in those cases
@@ -538 +536 @@
     // Reset IDs
     m_NextEntityId = SYSTEM_ENTITY + 1;
     m_NextLocalEntityId = FIRST_LOCAL_ENTITY;
 }
 
+void CComponentManager::SetRNGSeed(u32 seed)
+{
+    m_RNG.seed(seed);
+}
+
 void CComponentManager::RegisterComponentType(InterfaceId iid, ComponentTypeId cid, AllocFunc alloc, DeallocFunc dealloc,
         const char* name, const std::string& schema)
 {
     ComponentType c(CT_Native, iid, alloc, dealloc, name, schema, std::move(DefPersistentRooted<JS::Value>()));
     m_ComponentTypesById.insert(std::make_pair(cid, std::move(c)));

source/simulation2/system/ComponentManager.h

@@ -1 @@
-/* Copyright (C) 2015 Wildfire Games.
+/* Copyright (C) 2016 Wildfire Games.
  * This file is part of 0 A.D.
  *
  * 0 A.D. is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation, either version 2 of the License, or
@@ -293 +293 @@
      * Resets the dynamic simulation state (deletes all entities, resets entity ID counters;
      * doesn't unload/reload component scripts).
      */
     void ResetState();
 
+    /**
+     * Initializes the random number generator with a seed determined by the host.
+     */
+    void SetRNGSeed(u32 seed);
+
     // Various state serialization functions:
     bool ComputeStateHash(std::string& outHash, bool quick);
     bool DumpDebugState(std::ostream& stream, bool includeDebugInfo);
     // FlushDestroyedComponents must be called before SerializeState (since the destruction queue
     // won't get serialized)

source/simulation2/tests/test_ComponentManager.h

@@ -94 +94 @@
         TS_ASSERT_EQUALS(man.AllocateNewEntity(), (u32)2);
         TS_ASSERT_EQUALS(man.AllocateNewEntity(3), (u32)3);
         TS_ASSERT_EQUALS(man.AllocateNewLocalEntity(), (u32)FIRST_LOCAL_ENTITY);
     }
 
+    void test_rng()
+    {
+        // Ensure we get the same random number with the same seed
+        // and two different numbers with two different seeds
+        for (int test=0; test<2; ++test)
+        {
+            CSimContext context;
+            CComponentManager man(context, g_ScriptRuntime);
+            man.SetRNGSeed(1);
+            double first;
+            if (!man.m_ScriptInterface.MathRandom(first))
+                TS_FAIL("Couldn't get random number!");
+
+            CSimContext context2;
+            CComponentManager man2(context2, g_ScriptRuntime);
+            double second;
+            man2.SetRNGSeed(test == 0 ? 1 : 2);
+            if (!man2.m_ScriptInterface.MathRandom(second))
+                TS_FAIL("Couldn't get random number!");
+
+            if (test == 0)
+                TS_ASSERT_EQUALS(first, second);
+
+            if (test == 1)
+                TS_ASSERT_DIFFERS(first, second);
+        }
+    }
+
     void test_AddComponent_errors()
     {
         CSimContext context;
         CComponentManager man(context, g_ScriptRuntime);
         man.LoadComponentTypes();