4 files changed, 220 insertions, 114 deletions

diff --git a/src/BiomeDef.cpp b/src/BiomeDef.cpp
index 188e06173..3e34ebdbe 100644
--- a/src/BiomeDef.cpp
+++ b/src/BiomeDef.cpp
@@ -222,3 +222,130 @@ bool IsBiomeCold(EMCSBiome a_Biome)
 
 
 
+
+int GetSnowStartHeight(EMCSBiome a_Biome)
+{
+	switch (a_Biome)
+	{
+		case biIcePlainsSpikes:
+		case biIcePlains:
+		case biIceMountains:
+		case biFrozenRiver:
+		case biColdBeach:
+		case biColdTaiga:
+		case biColdTaigaHills:
+		case biColdTaigaM:
+		{
+			// Always snow
+			return 0;
+		}
+	
+		case biExtremeHills:
+		case biExtremeHillsM:
+		case biExtremeHillsPlus:
+		case biExtremeHillsPlusM:
+		case biStoneBeach:
+		{
+			// Starts snowing at 96
+			return 96;
+		}
+
+		case biTaiga:
+		case biTaigaHills:
+		case biTaigaM:
+		{
+			// Start snowing at 130
+			return 130;
+		}
+
+		case biMegaTaiga:
+		case biMegaSpruceTaiga:
+		case biMegaTaigaHills:
+		case biMegaSpruceTaigaHills:
+		{
+			// Start snowing at 160
+			return 160;
+		}
+
+		case biRiver:
+		case biOcean:
+		case biDeepOcean:
+		{
+			// Starts snowing at 280
+			return 280;
+		}
+
+		case biBirchForest:
+		case biBirchForestHills:
+		case biBirchForestM:
+		case biBirchForestHillsM:
+		{
+			// Starts snowing at 335
+			return 335;
+		}
+
+		case biForest:
+		case biForestHills:
+		case biFlowerForest:
+		case biRoofedForest:
+		case biRoofedForestM:
+		{
+			// Starts snowing at 400
+			return 400;
+		}
+
+		case biPlains:
+		case biSunflowerPlains:
+		case biSwampland:
+		case biSwamplandM:
+		case biBeach:
+		{
+			// Starts snowing at 460
+			return 460;
+		}
+
+		case biMushroomIsland:
+		case biMushroomShore:
+		{
+			// Starts snowing at 520
+			return 520;
+		}
+
+		case biJungle:
+		case biJungleHills:
+		case biJungleM:
+		case biJungleEdge:
+		case biJungleEdgeM:
+		{
+			// Starts snowing at 550
+			return 550;
+		}
+
+		case biDesert:
+		case biDesertHills:
+		case biDesertM:
+		case biSavanna:
+		case biSavannaM:
+		case biSavannaPlateau:
+		case biSavannaPlateauM:
+		case biMesa:
+		case biMesaBryce:
+		case biMesaPlateau:
+		case biMesaPlateauF:
+		case biMesaPlateauFM:
+		case biMesaPlateauM:
+		{
+			// These biomes don't actualy have any downfall.
+			return 1000;
+		}
+
+		default:
+		{
+			return 0;
+		}
+	}
+}
+
+
+
+
diff --git a/src/BiomeDef.h b/src/BiomeDef.h
index 84751cfd7..cda12556a 100644
--- a/src/BiomeDef.h
+++ b/src/BiomeDef.h
@@ -129,4 +129,7 @@ extern bool IsBiomeVeryCold(EMCSBiome a_Biome);
 Doesn't report Very Cold biomes, use IsBiomeVeryCold() for those. */
 extern bool IsBiomeCold(EMCSBiome a_Biome);
 
+/** Returns the height when a biome when a biome starts snowing.*/
+extern int GetSnowStartHeight(EMCSBiome a_Biome);
+
 // tolua_end
diff --git a/src/Chunk.cpp b/src/Chunk.cpp
index 08cb237c3..e05fa4a99 100644
--- a/src/Chunk.cpp
+++ b/src/Chunk.cpp
@@ -874,80 +874,71 @@ void cChunk::ApplyWeatherToTop()
 	
 	int X = m_World->GetTickRandomNumber(15);
 	int Z = m_World->GetTickRandomNumber(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))
+
+	// TODO: Check light levels, don't snow over when the BlockLight is higher than (7?)
+	int Height = GetHeight(X, Z);
+
+	if (GetSnowStartHeight(GetBiomeAt(X, Z)) > Height)
+	{
+		return;
+	}
+
+	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])
 			{
-				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++)
+				case E_BLOCK_AIR:
 				{
-					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);
+					MaxSize = 0;
+					break;
 				}
-				else if (TopMeta > MaxSize)
+				case E_BLOCK_SNOW:
 				{
-					FastSetBlock(X, Height, Z, E_BLOCK_SNOW, TopMeta - 1);
+					MaxSize = std::min(BlockMeta[i] + 1, MaxSize);
+					break;
 				}
 			}
-			else if (cBlockInfo::IsSnowable(TopBlock) && (Height + 1 < cChunkDef::Height))
-			{
-				SetBlock(X, Height + 1, Z, E_BLOCK_SNOW, 0);
-			}
-			else if (IsBlockWater(TopBlock) && (TopMeta == 0))
-			{
-				SetBlock(X, Height, Z, E_BLOCK_ICE, 0);
-			}
-			else if (
-				(m_World->IsDeepSnowEnabled()) &&
-				(
-					(TopBlock == E_BLOCK_RED_ROSE) ||
-					(TopBlock == E_BLOCK_YELLOW_FLOWER) ||
-					(TopBlock == E_BLOCK_RED_MUSHROOM) ||
-					(TopBlock == E_BLOCK_BROWN_MUSHROOM)
-				)
-			)
-			{
-				SetBlock(X, Height, Z, E_BLOCK_SNOW, 0);
-			}
-			break;
-		}  // case (snowy biomes)
-		default:
+		}
+		if (TopMeta < MaxSize)
 		{
-			break;
+			FastSetBlock(X, Height, Z, E_BLOCK_SNOW, TopMeta + 1);
+		}
+		else if (TopMeta > MaxSize)
+		{
+			FastSetBlock(X, Height, Z, E_BLOCK_SNOW, TopMeta - 1);
 		}
-	}  // switch (biome)
+	}
+	else if (cBlockInfo::IsSnowable(TopBlock) && (Height + 1 < cChunkDef::Height))
+	{
+		SetBlock(X, Height + 1, Z, E_BLOCK_SNOW, 0);
+	}
+	else if (IsBlockWater(TopBlock) && (TopMeta == 0))
+	{
+		SetBlock(X, Height, Z, E_BLOCK_ICE, 0);
+	}
+	else if (
+		(m_World->IsDeepSnowEnabled()) &&
+		(
+			(TopBlock == E_BLOCK_RED_ROSE) ||
+			(TopBlock == E_BLOCK_YELLOW_FLOWER) ||
+			(TopBlock == E_BLOCK_RED_MUSHROOM) ||
+			(TopBlock == E_BLOCK_BROWN_MUSHROOM)
+		)
+	)
+	{
+		SetBlock(X, Height, Z, E_BLOCK_SNOW, 0);
+	}
 }
 
 
diff --git a/src/Generating/FinishGen.cpp b/src/Generating/FinishGen.cpp
index e10cb00f8..d8fb9c8c0 100644
--- a/src/Generating/FinishGen.cpp
+++ b/src/Generating/FinishGen.cpp
@@ -470,30 +470,22 @@ void cFinishGenSnow::GenFinish(cChunkDesc & a_ChunkDesc)
 	{
 		for (int x = 0; x < cChunkDef::Width; x++)
 		{
-			switch (a_ChunkDesc.GetBiome(x, z))
+			int Height = a_ChunkDesc.GetHeight(x, z);
+			if (GetSnowStartHeight(a_ChunkDesc.GetBiome(x, z)) > Height)
 			{
-				case biIcePlains:
-				case biIceMountains:
-				case biTaiga:
-				case biTaigaHills:
-				case biFrozenRiver:
-				case biFrozenOcean:
-				{
-					int Height = a_ChunkDesc.GetHeight(x, z);
-					if (cBlockInfo::IsSnowable(a_ChunkDesc.GetBlockType(x, Height, z)) && (Height < cChunkDef::Height - 1))
-					{
-						a_ChunkDesc.SetBlockType(x, Height + 1, z, E_BLOCK_SNOW);
-						a_ChunkDesc.SetHeight(x, z, Height + 1);
-					}
-					break;
-				}
-				default:
-				{
-					// There's no snow in the other biomes.
-					break;
-				}
+				// Height isn't high enough for snow to start forming.
+				continue;
 			}
-		}
+
+			if (!cBlockInfo::IsSnowable(a_ChunkDesc.GetBlockType(x, Height, z)) && (Height < cChunkDef::Height - 1))
+			{
+				// The top block can't be snown over.
+				continue;
+			}
+
+			a_ChunkDesc.SetBlockType(x, Height + 1, z, E_BLOCK_SNOW);
+			a_ChunkDesc.SetHeight(x, z, Height + 1);
+		}  // for x
 	}  // for z
 }
 
@@ -511,34 +503,27 @@ void cFinishGenIce::GenFinish(cChunkDesc & a_ChunkDesc)
 	{
 		for (int x = 0; x < cChunkDef::Width; x++)
 		{
-			switch (a_ChunkDesc.GetBiome(x, z))
+			int Height = a_ChunkDesc.GetHeight(x, z);
+			if (GetSnowStartHeight(a_ChunkDesc.GetBiome(x, z)) > Height)
 			{
-				case biIcePlains:
-				case biIceMountains:
-				case biTaiga:
-				case biTaigaHills:
-				case biFrozenRiver:
-				case biFrozenOcean:
-				{
-					int Height = a_ChunkDesc.GetHeight(x, z);
-					switch (a_ChunkDesc.GetBlockType(x, Height, z))
-					{
-						case E_BLOCK_WATER:
-						case E_BLOCK_STATIONARY_WATER:
-						{
-							a_ChunkDesc.SetBlockType(x, Height, z, E_BLOCK_ICE);
-							break;
-						}
-					}
-					break;
-				}
-				default:
-				{
-					// No icy water in other biomes.
-					break;
-				}
+				// Height isn't high enough for snow to start forming.
+				continue;
 			}
-		}
+
+			if (!IsBlockWater(a_ChunkDesc.GetBlockType(x, Height, z)))
+			{
+				// The block isn't a water block.
+				continue;
+			}
+
+			if (a_ChunkDesc.GetBlockMeta(x, Height, z) != 0)
+			{
+				// The water block isn't a source block.
+				continue;
+			}
+
+			a_ChunkDesc.SetBlockType(x, Height, z, E_BLOCK_ICE);
+		}  // for x
 	}  // for z
 }