improve rain simulation (#4017)

* Uses vanilla logic to decide which blocks rain falls through.
 * Rain falls infinitely above the world, and stops at y=0.
 * Entities will now be extinguished if they are under rain-blocking
blocks, and fire will now be extinguished by rain similarly.
 * Create IsWeatherWetAtXYZ to identify wetness at a particular location. 
 * Use new code for enderman rain detection.
 * Fixes issue #916
 * Disable warnings for global constructors in the fire simulator.

Server/Plugins/APIDump/APIDesc.lua

@@ -238,7 +238,7 @@ return
 							Type = "boolean",
 						},
 					},
-					Notes = "Returns whether the specified block type will be destroyed after a single hit.",
+					Notes = "Returns true if the specified block type will be destroyed after a single hit.",
 				},
 				IsPistonBreakable =
 				{
@@ -256,7 +256,43 @@ return
 							Type = "boolean",
 						},
 					},
-					Notes = "Returns whether a piston can break the specified block type.",
+					Notes = "Returns true if a piston can break the specified block type.",
+				},
+				IsRainBlocker =
+				{
+					IsStatic = true,
+					Params =
+					{
+						{
+							Name = "BlockType",
+							Type = "number",
+						},
+					},
+					Returns =
+					{
+						{
+							Type = "boolean",
+						},
+					},
+					Notes = "Returns true if the specified block type blocks rain from passing through.",
+				},
+				IsSkylightDispersant =
+				{
+					IsStatic = true,
+					Params =
+					{
+						{
+							Name = "BlockType",
+							Type = "number",
+						},
+					},
+					Returns =
+					{
+						{
+							Type = "boolean",
+						},
+					},
+					Notes = "Returns true if skylight is impeded by passage through a block of the specified type.",
 				},
 				IsSnowable =
 				{
@@ -294,24 +330,6 @@ return
 					},
 					Notes = "Returns whether the specified block type is solid.",
 				},
-				IsSkylightDispersant =
-				{
-					IsStatic = true,
-					Params =
-					{
-						{
-							Name = "BlockType",
-							Type = "number",
-						},
-					},
-					Returns =
-					{
-						{
-							Type = "boolean",
-						},
-					},
-					Notes = "Returns true if skylight is impeded by passage through a block of the specified type.",
-				},
 				IsTransparent =
 				{
 					IsStatic = true,

Server/Plugins/APIDump/Classes/World.lua

@@ -2237,7 +2237,7 @@ function OnAllChunksAvailable()</pre> All return values from the callbacks are i
 						Type = "boolean",
 					},
 				},
-				Notes = "Returns true if the current world is raining (no thunderstorm).",
+				Notes = "Returns true if the current weather is rainy.",
 			},
 			IsWeatherRainAt =
 			{
@@ -2258,7 +2258,7 @@ function OnAllChunksAvailable()</pre> All return values from the callbacks are i
 						Type = "boolean",
 					},
 				},
-				Notes = "Returns true if the specified location is raining (takes biomes into account - it never rains in a desert).",
+				Notes = "Returns true if it is rainy at the specified location. This takes into account biomes.",
 			},
 			IsWeatherStorm =
 			{
@@ -2268,7 +2268,7 @@ function OnAllChunksAvailable()</pre> All return values from the callbacks are i
 						Type = "boolean",
 					},
 				},
-				Notes = "Returns true if the current world is stormy.",
+				Notes = "Returns true if the current weather is stormy.",
 			},
 			IsWeatherStormAt =
 			{
@@ -2289,7 +2289,7 @@ function OnAllChunksAvailable()</pre> All return values from the callbacks are i
 						Type = "boolean",
 					},
 				},
-				Notes = "Returns true if the specified location is stormy (takes biomes into account - no storm in a desert).",
+				Notes = "Returns true if it is stormy at the specified location. This takes into account biomes.",
 			},
 			IsWeatherSunny =
 			{
@@ -2320,7 +2320,7 @@ function OnAllChunksAvailable()</pre> All return values from the callbacks are i
 						Type = "boolean",
 					},
 				},
-				Notes = "Returns true if the current weather is sunny at the specified location (takes into account biomes).",
+				Notes = "Returns true if it is sunny at the specified location. This takes into account biomes.",
 			},
 			IsWeatherWet =
 			{
@@ -2330,7 +2330,7 @@ function OnAllChunksAvailable()</pre> All return values from the callbacks are i
 						Type = "boolean",
 					},
 				},
-				Notes = "Returns true if the current world has any precipitation (rain or storm).",
+				Notes = "Returns true if the world currently has any precipitation - rain, storm or snow.",
 			},
 			IsWeatherWetAt =
 			{
@@ -2351,7 +2351,24 @@ function OnAllChunksAvailable()</pre> All return values from the callbacks are i
 						Type = "boolean",
 					},
 				},
-				Notes = "Returns true if the specified location has any precipitation (rain or storm) (takes biomes into account, deserts are never wet).",
+				Notes = "Returns true if it is raining or storming at the specified location. This takes into account biomes.",
+			},
+			IsWeatherWetAtXYZ =
+			{
+				Params =
+				{
+					{
+						Name = "Pos",
+						Type = "Vector3i",
+					},
+				},
+				Returns =
+				{
+					{
+						Type = "boolean",
+					},
+				},
+				Notes = "Returns true if the specified location has wet weather (rain or storm), using the same logic as IsWeatherWetAt, except that any rain-blocking blocks above the specified position will block the precipitation and this function will return false.",
 			},
 			PrepareChunk =
 			{
@@ -3637,4 +3654,3 @@ World:ForEachEntity(
 		},
 	},
 }
-

src/BlockInfo.cpp

@@ -464,6 +464,16 @@ cBlockInfo::cBlockInfoArray::cBlockInfoArray()
 	Info[E_BLOCK_YELLOW_SHULKER_BOX           ].m_PistonBreakable = true;
 
 
+	/* Blocks that block rain or snow's passage:
+	*  All solid blocks are also rain blockers, and they are set automatically
+	*  at the end of this function.
+	*/
+	Info[E_BLOCK_SIGN_POST                    ].m_IsRainBlocker = true;
+	Info[E_BLOCK_WALLSIGN                     ].m_IsRainBlocker = true;
+	Info[E_BLOCK_WALL_BANNER                  ].m_IsRainBlocker = true;
+	Info[E_BLOCK_STANDING_BANNER              ].m_IsRainBlocker = true;
+
+
 	// Blocks that can be snowed over:
 	Info[E_BLOCK_BEDROCK                      ].m_IsSnowable = true;
 	Info[E_BLOCK_BLOCK_OF_COAL                ].m_IsSnowable = true;
@@ -554,8 +564,8 @@ cBlockInfo::cBlockInfoArray::cBlockInfoArray()
 	Info[E_BLOCK_BIG_FLOWER                   ].m_IsSolid = false;
 	Info[E_BLOCK_BROWN_MUSHROOM               ].m_IsSolid = false;
 	Info[E_BLOCK_CARROTS                      ].m_IsSolid = false;
-	Info[E_BLOCK_CHORUS_PLANT                 ].m_IsSolid = false;
 	Info[E_BLOCK_CHORUS_FLOWER                ].m_IsSolid = false;
+	Info[E_BLOCK_CHORUS_PLANT                 ].m_IsSolid = false;
 	Info[E_BLOCK_COBWEB                       ].m_IsSolid = false;
 	Info[E_BLOCK_CROPS                        ].m_IsSolid = false;
 	Info[E_BLOCK_DANDELION                    ].m_IsSolid = false;
@@ -575,17 +585,17 @@ cBlockInfo::cBlockInfoArray::cBlockInfoArray()
 	Info[E_BLOCK_POTATOES                     ].m_IsSolid = false;
 	Info[E_BLOCK_POWERED_RAIL                 ].m_IsSolid = false;
 	Info[E_BLOCK_RAIL                         ].m_IsSolid = false;
+	Info[E_BLOCK_RED_MUSHROOM                 ].m_IsSolid = false;
 	Info[E_BLOCK_REDSTONE_TORCH_OFF           ].m_IsSolid = false;
 	Info[E_BLOCK_REDSTONE_TORCH_ON            ].m_IsSolid = false;
 	Info[E_BLOCK_REDSTONE_WIRE                ].m_IsSolid = false;
-	Info[E_BLOCK_RED_MUSHROOM                 ].m_IsSolid = false;
 	Info[E_BLOCK_REEDS                        ].m_IsSolid = false;
 	Info[E_BLOCK_SAPLING                      ].m_IsSolid = false;
 	Info[E_BLOCK_SIGN_POST                    ].m_IsSolid = false;
 	Info[E_BLOCK_SNOW                         ].m_IsSolid = false;
+	Info[E_BLOCK_STANDING_BANNER              ].m_IsSolid = false;
 	Info[E_BLOCK_STATIONARY_LAVA              ].m_IsSolid = false;
 	Info[E_BLOCK_STATIONARY_WATER             ].m_IsSolid = false;
-	Info[E_BLOCK_STANDING_BANNER              ].m_IsSolid = false;
 	Info[E_BLOCK_STONE_BUTTON                 ].m_IsSolid = false;
 	Info[E_BLOCK_STONE_PRESSURE_PLATE         ].m_IsSolid = false;
 	Info[E_BLOCK_TALL_GRASS                   ].m_IsSolid = false;
@@ -974,8 +984,9 @@ cBlockInfo::cBlockInfoArray::cBlockInfoArray()
 	Info[E_BLOCK_RED_SHULKER_BOX              ].m_Hardness = 0.2f;
 	Info[E_BLOCK_BLACK_SHULKER_BOX            ].m_Hardness = 0.2f;
 	Info[E_BLOCK_STRUCTURE_BLOCK              ].m_Hardness = -1.0f;
+
+	for (size_t i = 0; i < Info.size(); ++i)
+	{
+		Info[i].m_IsRainBlocker |= Info[i].m_IsSolid;
+	}
 }
-
-
-
-

src/BlockInfo.h

@@ -37,7 +37,10 @@ public:
 	/** Can a piston break this block? */
 	bool m_PistonBreakable;
 
-	/** Does a block disperse sky light? (only relevant for transparent blocks) */
+	/** Does this block block the passage of rain? */
+	bool m_IsRainBlocker;
+
+	/** Does this block disperse sky light? (only relevant for transparent blocks) */
 	bool m_IsSkylightDispersant;
 
 	/** Can this block hold snow atop? */
@@ -79,6 +82,7 @@ public:
 	inline static bool IsTransparent              (BLOCKTYPE a_Type) { return Get(a_Type).m_Transparent;         }
 	inline static bool IsOneHitDig                (BLOCKTYPE a_Type) { return Get(a_Type).m_OneHitDig;           }
 	inline static bool IsPistonBreakable          (BLOCKTYPE a_Type) { return Get(a_Type).m_PistonBreakable;     }
+	inline static bool IsRainBlocker              (BLOCKTYPE a_Type) { return Get(a_Type).m_IsRainBlocker;       }
 	inline static bool IsSkylightDispersant       (BLOCKTYPE a_Type)
 	{
 		return ((Get(a_Type).m_IsSkylightDispersant) || (Get(a_Type).m_SpreadLightFalloff > 1));
@@ -102,6 +106,7 @@ public:
 		, m_Transparent(false)
 		, m_OneHitDig(false)
 		, m_PistonBreakable(false)
+		, m_IsRainBlocker(false)
 		, m_IsSkylightDispersant(false)
 		, m_IsSnowable(false)
 		, m_IsSolid(true)
@@ -149,7 +154,3 @@ inline cBlockHandler * BlockHandler(BLOCKTYPE a_BlockType)
 {
 	return cBlockInfo::Get(a_BlockType).m_Handler.get();
 }
-
-
-
-

src/Blocks/WorldInterface.h

@@ -65,7 +65,7 @@ public:
 
 	virtual void SetTimeOfDay(int a_TimeOfDay) = 0;
 
-	/** Returns true if it is raining, stormy or snowing at the specified location. This takes into account biomes. */
+	/** Returns true if it is raining or storming at the specified location. This takes into account biomes. */
 	virtual bool IsWeatherWetAt(int a_BlockX, int a_BlockZ) = 0;
 
 	/** Returns or sets the minumim or maximum netherportal width */

src/Entities/Entity.cpp

@@ -1172,12 +1172,9 @@ void cEntity::TickBurning(cChunk & a_Chunk)
 	}
 
 	// Fire is extinguished by rain
-	if (GetWorld()->IsWeatherWetAt(POSX_TOINT, POSZ_TOINT))
+	if (GetWorld()->IsWeatherWetAtXYZ(GetPosition().Floor()))
 	{
-		if (POSY_TOINT > m_World->GetHeight(POSX_TOINT, POSZ_TOINT))
+		m_TicksLeftBurning = 0;
-		{
-			m_TicksLeftBurning = 0;
-		}
 	}
 
 	// Do the burning damage:

src/Mobs/Enderman.cpp

@@ -194,37 +194,13 @@ void cEnderman::Tick(std::chrono::milliseconds a_Dt, cChunk & a_Chunk)
 	}
 
 	// Take damage when touching water, drowning damage seems to be most appropriate
-	if (CheckRain() || IsSwimming())
+	if (
+		cChunkDef::IsValidHeight(POSY_TOINT) &&
+		(GetWorld()->IsWeatherWetAtXYZ(GetPosition().Floor()) || IsSwimming())
+	)
 	{
 		EventLosePlayer();
 		TakeDamage(dtDrowning, nullptr, 1, 0);
 		// TODO teleport to a safe location
 	}
 }
-
-
-
-
-
-bool cEnderman::CheckRain(void)
-{
-	if (!GetWorld()->IsWeatherRain())
-	{
-		return false;
-	}
-
-	Vector3d coords = GetPosition();
-	for (int Y = static_cast<int>(coords.y); Y < cChunkDef::Height; ++Y)
-	{
-		BLOCKTYPE Block = m_World->GetBlock(static_cast<int>(coords.x), Y, static_cast<int>(coords.z));
-		if (Block != E_BLOCK_AIR)
-		{
-			return false;
-		}
-	}
-	return true;
-}
-
-
-
-

src/Mobs/Enderman.h

@@ -29,8 +29,6 @@ public:
 
 	/** Returns if the current sky light level is sufficient for the enderman to become aggravated */
 	bool CheckLight(void);
-	/** Returns if the enderman gets hit by the rain */
-	bool CheckRain(void);
 
 private:
 
@@ -39,7 +37,3 @@ private:
 	NIBBLETYPE CarriedMeta;
 
 } ;
-
-
-
-

src/Simulator/CMakeLists.txt

@@ -29,7 +29,6 @@ SET (HDRS
 	VaporizeFluidSimulator.h
 )
 
-
 if(NOT MSVC)
 	add_library(Simulator ${SRCS} ${HDRS})
 endif()

src/Simulator/FireSimulator.cpp

@@ -25,15 +25,22 @@
 
 #define MAX_CHANCE_REPLACE_FUEL 100000
 #define MAX_CHANCE_FLAMMABILITY 100000
+// The base chance that in a tick, rain will extinguish a fire block.
+#define CHANCE_BASE_RAIN_EXTINGUISH 0.2
+// The additional chance, multiplied by the meta of the fire block, that rain
+// will extinguish a fire block in a tick.
+#define CHANCE_AGE_M_RAIN_EXTINGUISH 0.03
 
 
 
 
 
-static const struct
+#ifdef __clang__
-{
+	#pragma clang diagnostic push
-	int x, y, z;
+	#pragma clang diagnostic ignored "-Wglobal-constructors"
-} gCrossCoords[] =
+#endif
+
+static const Vector3i gCrossCoords[] =
 {
 	{ 1, 0,  0},
 	{-1, 0,  0},
@@ -45,10 +52,7 @@ static const struct
 
 
 
-static const struct
+static const Vector3i gNeighborCoords[] =
-{
-	int x, y, z;
-} gNeighborCoords[] =
 {
 	{ 1,  0,  0},
 	{-1,  0,  0},
@@ -58,6 +62,10 @@ static const struct
 	{ 0,  0, -1},
 } ;
 
+#ifdef __clang__
+	#pragma clang diagnostic pop
+#endif
+
 
 
 
@@ -97,20 +105,39 @@ void cFireSimulator::SimulateChunk(std::chrono::milliseconds a_Dt, int a_ChunkX,
 		int x = itr->x;
 		int y = itr->y;
 		int z = itr->z;
+		auto AbsPos = cChunkDef::RelativeToAbsolute({x, y, z}, a_Chunk->GetPosX(), a_Chunk->GetPosZ());
 		BLOCKTYPE BlockType = a_Chunk->GetBlock(x, y, z);
 
 		if (!IsAllowedBlock(BlockType))
 		{
 			// The block is no longer eligible (not a fire block anymore; a player probably placed a block over the fire)
 			FLOG("FS: Removing block {%d, %d, %d}",
-				itr->x + a_ChunkX * cChunkDef::Width, itr->y, itr->z + a_ChunkZ * cChunkDef::Width
+				AbsPos.x, AbsPos.y, AbsPos.z
 			);
 			itr = Data.erase(itr);
 			continue;
 		}
 
+		auto BurnsForever = ((y > 0) && DoesBurnForever(a_Chunk->GetBlock(x, (y - 1), z)));
+		auto BlockMeta = a_Chunk->GetMeta(x, y, z);
+
+		auto Raining = std::any_of(std::begin(gCrossCoords), std::end(gCrossCoords),
+			[this, AbsPos](Vector3i cc)
+			{
+				return (m_World.IsWeatherWetAtXYZ(AbsPos + cc));
+			}
+		);
+
+		// Randomly burn out the fire if it is raining:
+		if (!BurnsForever && Raining && GetRandomProvider().RandBool(CHANCE_BASE_RAIN_EXTINGUISH + (BlockMeta * CHANCE_AGE_M_RAIN_EXTINGUISH)))
+		{
+			a_Chunk->SetBlock(x, y, z, E_BLOCK_AIR, 0);
+			itr = Data.erase(itr);
+			continue;
+		}
+
 		// Try to spread the fire:
-		TrySpreadFire(a_Chunk, itr->x, itr->y, itr->z);
+		TrySpreadFire(a_Chunk, x, y, z);
 
 		itr->Data -= NumMSecs;
 		if (itr->Data >= 0)
@@ -120,30 +147,30 @@ void cFireSimulator::SimulateChunk(std::chrono::milliseconds a_Dt, int a_ChunkX,
 			continue;
 		}
 
-		// Burn out the fire one step by increasing the meta:
 		/*
 		FLOG("FS: Fire at {%d, %d, %d} is stepping",
 			itr->x + a_ChunkX * cChunkDef::Width, itr->y, itr->z + a_ChunkZ * cChunkDef::Width
 		);
 		*/
-		NIBBLETYPE BlockMeta = a_Chunk->GetMeta(x, y, z);
+		// Has the fire burnt out?
 		if (BlockMeta == 0x0f)
 		{
-			// The fire burnt out completely
 			FLOG("FS: Fire at {%d, %d, %d} burnt out, removing the fire block",
 				itr->x + a_ChunkX * cChunkDef::Width, itr->y, itr->z + a_ChunkZ * cChunkDef::Width
 			);
-			a_Chunk->SetBlock(itr->x, itr->y, itr->z, E_BLOCK_AIR, 0);
+			a_Chunk->SetBlock(x, y, z, E_BLOCK_AIR, 0);
-			RemoveFuelNeighbors(a_Chunk, itr->x, itr->y, itr->z);
+			RemoveFuelNeighbors(a_Chunk, x, y, z);
 			itr = Data.erase(itr);
 			continue;
 		}
 
-		if ((itr->y > 0) && (!DoesBurnForever(a_Chunk->GetBlock(itr->x, itr->y - 1, itr->z))))
+		// Burn out the fire one step by increasing the meta:
+		if (!BurnsForever)
 		{
 			a_Chunk->SetMeta(x, y, z, BlockMeta + 1);
 		}
-		itr->Data = GetBurnStepTime(a_Chunk, itr->x, itr->y, itr->z);  // TODO: Add some randomness into this
+
+		itr->Data = GetBurnStepTime(a_Chunk, x, y, z);  // TODO: Add some randomness into this
 		++itr;
 	}  // for itr - Data[]
 }
@@ -283,7 +310,7 @@ int cFireSimulator::GetBurnStepTime(cChunk * a_Chunk, int a_RelX, int a_RelY, in
 		}
 	}  // for i - gCrossCoords[]
 
-	if (!IsBlockBelowSolid && (a_RelY >= 0))
+	if (!IsBlockBelowSolid)
 	{
 		// Checked through everything, nothing was flammable
 		// If block below isn't solid, we can't have fire, it would be a non-fueled fire
@@ -427,7 +454,3 @@ bool cFireSimulator::CanStartFireInBlock(cChunk * a_NearChunk, int a_RelX, int a
 	}  // for i - Coords[]
 	return false;
 }
-
-
-
-

src/World.cpp

@@ -542,6 +542,34 @@ void cWorld::ChangeWeather(void)
 
 
 
+bool cWorld::IsWeatherWetAtXYZ(Vector3i a_Pos)
+{
+	if ((a_Pos.y < 0) || !IsWeatherWetAt(a_Pos.x, a_Pos.z))
+	{
+		return false;
+	}
+
+	if (a_Pos.y >= cChunkDef::Height)
+	{
+		return true;
+	}
+
+	for (int y = GetHeight(a_Pos.x, a_Pos.z); y >= a_Pos.y; y--)
+	{
+		auto BlockType = GetBlock({a_Pos.x, y, a_Pos.z});
+		if (cBlockInfo::IsRainBlocker(BlockType))
+		{
+			return false;
+		}
+	}
+
+	return true;
+}
+
+
+
+
+
 void cWorld::SetNextBlockTick(int a_BlockX, int a_BlockY, int a_BlockZ)
 {
 	return m_ChunkMap->SetNextBlockTick(a_BlockX, a_BlockY, a_BlockZ);

src/World.h

@@ -766,7 +766,7 @@ public:
 	/** Returns the current weather. Instead of comparing values directly to the weather constants, use IsWeatherXXX() functions, if possible */
 	eWeather GetWeather(void) const { return m_Weather; }
 
-	/** Returns true if the current weather is sun */
+	/** Returns true if the current weather is sunny. */
 	bool IsWeatherSunny(void) const { return (m_Weather == wSunny); }
 
 	/** Returns true if it is sunny at the specified location. This takes into account biomes. */
@@ -775,7 +775,7 @@ public:
 		return (IsWeatherSunny() || IsBiomeNoDownfall(GetBiomeAt(a_BlockX, a_BlockZ)));
 	}
 
-	/** Returns true if the current weather is rain */
+	/** Returns true if the current weather is rainy. */
 	bool IsWeatherRain(void) const { return (m_Weather == wRain); }
 
 	/** Returns true if it is raining at the specified location. This takes into account biomes. */
@@ -784,7 +784,7 @@ public:
 		return (IsWeatherRain() && !IsBiomeNoDownfall(GetBiomeAt(a_BlockX, a_BlockZ)));
 	}
 
-	/** Returns true if the current weather is stormy */
+	/** Returns true if the current weather is stormy. */
 	bool IsWeatherStorm(void) const { return (m_Weather == wStorm); }
 
 	/** Returns true if the weather is stormy at the specified location. This takes into account biomes. */
@@ -793,15 +793,23 @@ public:
 		return (IsWeatherStorm() && !IsBiomeNoDownfall(GetBiomeAt(a_BlockX, a_BlockZ)));
 	}
 
-	/** Returns true if the current weather has any precipitation - rain, storm or snow */
+	/** Returns true if the world currently has any precipitation - rain, storm or snow. */
 	bool IsWeatherWet(void) const { return !IsWeatherSunny(); }
 
-	/** Returns true if it is raining, stormy or snowing at the specified location. This takes into account biomes. */
+	/** Returns true if it is raining or storming at the specified location.
+	This takes into account biomes. */
 	virtual bool IsWeatherWetAt(int a_BlockX, int a_BlockZ) override
 	{
-		return (IsWeatherWet() && !IsBiomeNoDownfall(GetBiomeAt(a_BlockX, a_BlockZ)));
+		auto Biome = GetBiomeAt(a_BlockX, a_BlockZ);
+		return (IsWeatherWet() && !IsBiomeNoDownfall(Biome) && !IsBiomeCold(Biome));
 	}
 
+	/** Returns true if the specified location has wet weather (rain or storm),
+	using the same logic as IsWeatherWetAt, except that any rain-blocking blocks
+	above the specified position will block the precipitation and this function
+	will return false. */
+	virtual bool IsWeatherWetAtXYZ(Vector3i a_Pos);
+
 	/** Returns the seed of the world. */
 	int GetSeed(void) { return m_Generator.GetSeed(); }
 
@@ -1129,7 +1137,3 @@ private:
 	void SetChunkData(cSetChunkData & a_SetChunkData);
 
 };  // tolua_export
-
-
-
-