5 files changed, 91 insertions, 2 deletions

diff --git a/source/BlockID.cpp b/source/BlockID.cpp
index 6553b612e..cb2d16efa 100644
--- a/source/BlockID.cpp
+++ b/source/BlockID.cpp
@@ -455,6 +455,7 @@ public:
 		g_BlockPistonBreakable[E_BLOCK_YELLOW_FLOWER]         = true;
 
 		// Blocks that can be snowed over:
+		g_BlockIsSnowable[E_BLOCK_AIR]                   = false;
 		g_BlockIsSnowable[E_BLOCK_BROWN_MUSHROOM]        = false;
 		g_BlockIsSnowable[E_BLOCK_CACTUS]                = false;
 		g_BlockIsSnowable[E_BLOCK_CHEST]                 = false;
diff --git a/source/Chunk.cpp b/source/Chunk.cpp
index d10aa6dac..e6c2e527a 100644
--- a/source/Chunk.cpp
+++ b/source/Chunk.cpp
@@ -413,6 +413,8 @@ void cChunk::Tick(float a_Dt, MTRand & a_TickRandom)
 			m_IsDirty = ((cFurnaceEntity *)(*itr))->Tick( a_Dt ) | m_IsDirty;
 		}
 	}
+	
+	ApplyWeatherToTop(a_TickRandom);
 }
 
 
@@ -522,6 +524,88 @@ void cChunk::TickBlocks(MTRand & a_TickRandom)
 
 
 
+void cChunk::ApplyWeatherToTop(MTRand & a_TickRandom)
+{
+	if (
+		(a_TickRandom.randInt(100) != 0) ||
+		(
+			(m_World->GetWeather() != eWeather_Rain) &&
+			(m_World->GetWeather() != eWeather_ThunderStorm)
+		)
+	)
+	{
+		// Not the right weather, or not at this tick; bail out
+		return;
+	}
+	
+	int X = a_TickRandom.randInt(15);
+	int Z = a_TickRandom.randInt(15);
+	switch (GetBiomeAt(X, Z))
+	{
+		case biTaiga:
+		case biFrozenOcean:
+		case biFrozenRiver:
+		case biIcePlains:
+		case biIceMountains:
+		case biTaigaHills:
+		{
+			// TODO: Check light levels, don't snow over when the BlockLight is higher than (7?)
+			int Height = GetHeight(X, Z);
+			BLOCKTYPE TopBlock = GetBlock(X, Height, Z);
+			NIBBLETYPE TopMeta = GetMeta (X, Height, Z);
+			if (m_World->IsDeepSnowEnabled() && (TopBlock == E_BLOCK_SNOW))
+			{
+				int MaxSize = 7;
+				BLOCKTYPE  BlockType[4];
+				NIBBLETYPE BlockMeta[4];
+				UnboundedRelGetBlock(X - 1, Height, Z,     BlockType[0], BlockMeta[0]);
+				UnboundedRelGetBlock(X + 1, Height, Z,     BlockType[1], BlockMeta[1]);
+				UnboundedRelGetBlock(X,     Height, Z - 1, BlockType[2], BlockMeta[2]);
+				UnboundedRelGetBlock(X,     Height, Z + 1, BlockType[3], BlockMeta[3]);
+				for (int i = 0; i < 4; i++)
+				{
+					switch (BlockType[i])
+					{
+						case E_BLOCK_AIR:
+						{
+							MaxSize = 0;
+							break;
+						}
+						case E_BLOCK_SNOW:
+						{
+							MaxSize = std::min(BlockMeta[i] + 1, MaxSize);
+							break;
+						}
+					}
+				}
+				if (TopMeta < MaxSize)
+				{
+					FastSetBlock(X, Height, Z, E_BLOCK_SNOW, TopMeta + 1);
+				}
+				else if (TopMeta > MaxSize)
+				{
+					FastSetBlock(X, Height, Z, E_BLOCK_SNOW, TopMeta - 1);
+				}
+			}
+			else if (g_BlockIsSnowable[TopBlock])
+			{
+				SetBlock(X, Height + 1, Z, E_BLOCK_SNOW, 0);
+			}
+			else if ((TopBlock == E_BLOCK_WATER) || (TopBlock == E_BLOCK_STATIONARY_WATER))
+			{
+				SetBlock(X, Height, Z, E_BLOCK_ICE, 0);
+			}
+			break;
+		}  // case (snowy biomes)
+		
+		// TODO: Rainy biomes should check for farmland and cauldrons
+	}  // switch (biome)
+}
+
+
+
+
+
 void cChunk::GrowMelonPumpkin(int a_RelX, int a_RelY, int a_RelZ, BLOCKTYPE a_BlockType, MTRand & a_TickRandom)
 {
 	// Convert the stem BlockType into produce BlockType
diff --git a/source/Chunk.h b/source/Chunk.h
index 4bc99b8d2..e21868123 100644
--- a/source/Chunk.h
+++ b/source/Chunk.h
@@ -290,8 +290,9 @@ private:
 	void CheckBlocks(void);
 	
 	void TickBlocks  (MTRand & a_TickRandom);
-	void TickGrass   (int a_RelX, int a_RelY, int a_RelZ, MTRand & a_TickRandom);
-	void TickFarmland(int a_RelX, int a_RelY, int a_RelZ);
+	
+	/// Adds snow to the top of snowy biomes and hydrates farmland / fills cauldrons in rainy biomes
+	void ApplyWeatherToTop(MTRand & a_TickRandom);
 	
 	/// Grows sugarcane by the specified number of blocks, but no more than 3 blocks high (used by both bonemeal and ticking)
 	void GrowSugarcane   (int a_RelX, int a_RelY, int a_RelZ, int a_NumBlocks);
diff --git a/source/World.cpp b/source/World.cpp
index 9ca84156b..1834a49da 100644
--- a/source/World.cpp
+++ b/source/World.cpp
@@ -254,6 +254,7 @@ cWorld::cWorld( const AString & a_WorldName )
 	m_IsSugarcaneBonemealable   = IniFile.GetValueSetB("Plants",        "IsSugarcaneBonemealable",   false);
 	m_IsCactusBonemealable      = IniFile.GetValueSetB("Plants",        "IsCactusBonemealable",      false);
 	m_bEnabledPVP               = IniFile.GetValueSetB("PVP",           "Enabled",                   true);
+	m_IsDeepSnowEnabled         = IniFile.GetValueSetB("Physics",       "DeepSnow",                  false);
 
 	m_GameMode = (eGameMode)IniFile.GetValueSetI("GameMode", "GameMode", m_GameMode );
 
diff --git a/source/World.h b/source/World.h
index f9cc83f31..b54e82662 100644
--- a/source/World.h
+++ b/source/World.h
@@ -68,6 +68,7 @@ public:
 
 	eGameMode GetGameMode(void) const { return m_GameMode; }						//tolua_export
 	bool IsPVPEnabled(void) const { return m_bEnabledPVP; }							//tolua_export
+	bool IsDeepSnowEnabled(void) const { return m_IsDeepSnowEnabled; }
 
 	void SetWorldTime(long long a_WorldTime) { m_WorldTime = a_WorldTime; }			//tolua_export
 
@@ -425,6 +426,7 @@ private:
 	unsigned long long CurrentTick;
 	eGameMode m_GameMode;
 	bool m_bEnabledPVP;
+	bool m_IsDeepSnowEnabled;
 	float m_WorldTimeFraction; // When this > 1.f m_WorldTime is incremented by 20
 
 	// The cRedstone class simulates redstone and needs access to m_RSList