1 files changed, 398 insertions, 0 deletions

diff --git a/src/Blocks/BlockRail.h b/src/Blocks/BlockRail.h
new file mode 100644
index 000000000..24a101652
--- /dev/null
+++ b/src/Blocks/BlockRail.h
@@ -0,0 +1,398 @@
+
+#pragma once
+
+#include "BlockEntity.h"
+#include "../World.h"
+
+
+
+
+
+enum ENUM_PURE
+{
+	E_PURE_UPDOWN = 0,
+	E_PURE_DOWN = 1,
+	E_PURE_NONE = 2
+};
+
+
+
+
+
+class cBlockRailHandler :
+	public cBlockHandler
+{
+	typedef cBlockHandler super;
+	
+public:
+	cBlockRailHandler(BLOCKTYPE a_BlockType)
+		: cBlockHandler(a_BlockType)
+	{
+	}
+	
+	virtual bool GetPlacementBlockTypeMeta(
+		cWorld * a_World, cPlayer * a_Player,
+		int a_BlockX, int a_BlockY, int a_BlockZ, char a_BlockFace, 
+		int a_CursorX, int a_CursorY, int a_CursorZ,
+		BLOCKTYPE & a_BlockType, NIBBLETYPE & a_BlockMeta
+	) override
+	{
+		a_BlockType = m_BlockType;
+		a_BlockMeta = FindMeta(a_World, a_BlockX, a_BlockY, a_BlockZ);
+		return true;
+	}
+
+
+	virtual void OnNeighborChanged(cWorld *a_World, int a_BlockX, int a_BlockY, int a_BlockZ) override
+	{
+		NIBBLETYPE Meta = a_World->GetBlockMeta(a_BlockX, a_BlockY, a_BlockZ);
+		if (IsUnstable(a_World, a_BlockX, a_BlockY, a_BlockZ) && (Meta != FindMeta(a_World, a_BlockX, a_BlockY, a_BlockZ)))
+		{
+			a_World->FastSetBlock(a_BlockX, a_BlockY, a_BlockZ, m_BlockType, FindMeta(a_World, a_BlockX, a_BlockY, a_BlockZ));
+		}
+	}
+
+
+	virtual void ConvertToPickups(cItems & a_Pickups, NIBBLETYPE a_BlockMeta) override
+	{
+		super::ConvertToPickups(a_Pickups, 0);
+	}
+
+
+	virtual bool CanBeAt(int a_RelX, int a_RelY, int a_RelZ, const cChunk & a_Chunk) override
+	{
+		if (a_RelY <= 0)
+		{
+			return false;
+		}
+		if (!g_BlockIsSolid[a_Chunk.GetBlock(a_RelX, a_RelY - 1, a_RelZ)])
+		{
+			return false;
+		}
+
+		NIBBLETYPE Meta = a_Chunk.GetMeta(a_RelX, a_RelY, a_RelZ);
+		switch (Meta)
+		{
+			case E_META_RAIL_ASCEND_XP:
+			case E_META_RAIL_ASCEND_XM:
+			case E_META_RAIL_ASCEND_ZM:
+			case E_META_RAIL_ASCEND_ZP:
+			{
+				// Mapping between the meta and the neighbors that need checking
+				Meta -= E_META_RAIL_ASCEND_XP;  // Base index at zero
+				static const struct
+				{
+					int x, z;
+				} Coords[] =
+				{
+					{ 1,  0},  // east,  XP
+					{-1,  0},  // west,  XM
+					{ 0, -1},  // north, ZM
+					{ 0,  1},  // south, ZP
+				} ;
+				BLOCKTYPE  BlockType;
+				NIBBLETYPE BlockMeta;
+				if (!a_Chunk.UnboundedRelGetBlock(a_RelX + Coords[Meta].x, a_RelY, a_RelZ + Coords[Meta].z, BlockType, BlockMeta))
+				{
+					// Too close to the edge, cannot simulate
+					return true;
+				}
+				return g_BlockIsSolid[BlockType];
+			}
+		}
+		return true;
+	}
+
+	NIBBLETYPE FindMeta(cWorld *a_World, int a_BlockX, int a_BlockY, int a_BlockZ)
+	{
+		NIBBLETYPE Meta = 0;
+		char RailsCnt = 0;
+		bool Neighbors[8]; // 0 - EAST, 1 - WEST, 2 - NORTH, 3 - SOUTH, 4 - EAST UP, 5 - WEST UP, 6 - NORTH UP, 7 - SOUTH UP
+		memset(Neighbors, false, sizeof(Neighbors));
+		Neighbors[0] = (IsUnstable(a_World, a_BlockX + 1, a_BlockY, a_BlockZ) || !IsNotConnected(a_World, a_BlockX, a_BlockY, a_BlockZ, BLOCK_FACE_EAST, E_PURE_DOWN));
+		Neighbors[1] = (IsUnstable(a_World, a_BlockX - 1, a_BlockY, a_BlockZ) || !IsNotConnected(a_World, a_BlockX, a_BlockY, a_BlockZ, BLOCK_FACE_WEST, E_PURE_DOWN));
+		Neighbors[2] = (IsUnstable(a_World, a_BlockX, a_BlockY, a_BlockZ - 1) || !IsNotConnected(a_World, a_BlockX, a_BlockY, a_BlockZ, BLOCK_FACE_NORTH, E_PURE_DOWN));
+		Neighbors[3] = (IsUnstable(a_World, a_BlockX, a_BlockY, a_BlockZ + 1) || !IsNotConnected(a_World, a_BlockX, a_BlockY, a_BlockZ, BLOCK_FACE_SOUTH, E_PURE_DOWN));
+		Neighbors[4] = (IsUnstable(a_World, a_BlockX + 1, a_BlockY + 1, a_BlockZ) || !IsNotConnected(a_World, a_BlockX, a_BlockY + 1, a_BlockZ, BLOCK_FACE_EAST, E_PURE_NONE));
+		Neighbors[5] = (IsUnstable(a_World, a_BlockX - 1, a_BlockY + 1, a_BlockZ) || !IsNotConnected(a_World, a_BlockX, a_BlockY + 1, a_BlockZ, BLOCK_FACE_WEST, E_PURE_NONE));
+		Neighbors[6] = (IsUnstable(a_World, a_BlockX, a_BlockY + 1, a_BlockZ - 1) || !IsNotConnected(a_World, a_BlockX, a_BlockY + 1, a_BlockZ, BLOCK_FACE_NORTH, E_PURE_NONE));
+		Neighbors[7] = (IsUnstable(a_World, a_BlockX, a_BlockY + 1, a_BlockZ + 1) || !IsNotConnected(a_World, a_BlockX, a_BlockY + 1, a_BlockZ, BLOCK_FACE_SOUTH, E_PURE_NONE));
+		if (IsUnstable(a_World, a_BlockX + 1, a_BlockY - 1, a_BlockZ) || !IsNotConnected(a_World, a_BlockX, a_BlockY - 1, a_BlockZ, BLOCK_FACE_EAST))
+			Neighbors[0] = true;
+		if (IsUnstable(a_World, a_BlockX - 1, a_BlockY - 1, a_BlockZ) || !IsNotConnected(a_World, a_BlockX, a_BlockY - 1, a_BlockZ, BLOCK_FACE_WEST))
+			Neighbors[1] = true;
+		if (IsUnstable(a_World, a_BlockX, a_BlockY - 1, a_BlockZ - 1) || !IsNotConnected(a_World, a_BlockX, a_BlockY - 1, a_BlockZ, BLOCK_FACE_NORTH))
+			Neighbors[2] = true;
+		if (IsUnstable(a_World, a_BlockX, a_BlockY - 1, a_BlockZ + 1) || !IsNotConnected(a_World, a_BlockX, a_BlockY - 1, a_BlockZ, BLOCK_FACE_SOUTH))
+			Neighbors[3] = true;
+		for (int i = 0; i < 8; i++)
+		{
+			if (Neighbors[i])
+			{
+				RailsCnt++;
+			}
+		}
+		if (RailsCnt == 1)
+		{
+			if (Neighbors[7]) return E_META_RAIL_ASCEND_ZP;
+			else if (Neighbors[6]) return E_META_RAIL_ASCEND_ZM;
+			else if (Neighbors[5]) return E_META_RAIL_ASCEND_XM;
+			else if (Neighbors[4]) return E_META_RAIL_ASCEND_XP;
+			else if (Neighbors[0] || Neighbors[1]) return E_META_RAIL_XM_XP;
+			else if (Neighbors[2] || Neighbors[3]) return E_META_RAIL_ZM_ZP;
+			ASSERT(!"Weird neighbor count");
+			return Meta;
+		}
+		for (int i = 0; i < 4; i++)
+		{
+			if (Neighbors[i + 4])
+			{
+				Neighbors[i] = true;
+			}
+		}
+		if (RailsCnt > 1)
+		{
+			if      (Neighbors[3] && Neighbors[0]) return E_META_RAIL_CURVED_ZP_XP;
+			else if (Neighbors[3] && Neighbors[1]) return E_META_RAIL_CURVED_ZP_XM;
+			else if (Neighbors[2] && Neighbors[0]) return E_META_RAIL_CURVED_ZM_XP;
+			else if (Neighbors[2] && Neighbors[1]) return E_META_RAIL_CURVED_ZM_XM;
+			else if (Neighbors[7] && Neighbors[2]) return E_META_RAIL_ASCEND_ZP;
+			else if (Neighbors[3] && Neighbors[6]) return E_META_RAIL_ASCEND_ZM;
+			else if (Neighbors[5] && Neighbors[0]) return E_META_RAIL_ASCEND_XM;
+			else if (Neighbors[4] && Neighbors[1]) return E_META_RAIL_ASCEND_XP;
+			else if (Neighbors[0] && Neighbors[1]) return E_META_RAIL_XM_XP;
+			else if (Neighbors[2] && Neighbors[3]) return E_META_RAIL_ZM_ZP;
+			ASSERT(!"Weird neighbor count");
+		}
+		return Meta;
+	}
+
+
+	bool IsUnstable(cWorld * a_World, int a_BlockX, int a_BlockY, int a_BlockZ)
+	{
+		if (a_World->GetBlock(a_BlockX, a_BlockY, a_BlockZ) != E_BLOCK_RAIL)
+		{
+			return false;
+		}
+		NIBBLETYPE Meta = a_World->GetBlockMeta(a_BlockX, a_BlockY, a_BlockZ);
+		switch (Meta)
+		{
+			case E_META_RAIL_ZM_ZP:
+			{
+				if (
+					IsNotConnected(a_World, a_BlockX, a_BlockY, a_BlockZ, BLOCK_FACE_NORTH, E_PURE_DOWN) || 
+					IsNotConnected(a_World, a_BlockX, a_BlockY, a_BlockZ, BLOCK_FACE_SOUTH, E_PURE_DOWN)
+				)
+				{
+					return true;
+				}
+				break;
+			}
+			
+			case E_META_RAIL_XM_XP:
+			{
+				if (
+					IsNotConnected(a_World, a_BlockX, a_BlockY, a_BlockZ, BLOCK_FACE_EAST, E_PURE_DOWN) || 
+					IsNotConnected(a_World, a_BlockX, a_BlockY, a_BlockZ, BLOCK_FACE_WEST, E_PURE_DOWN)
+				)
+				{
+					return true;
+				}
+				break;
+			}
+			
+			case E_META_RAIL_ASCEND_XP:
+			{
+				if (
+					IsNotConnected(a_World, a_BlockX, a_BlockY + 1, a_BlockZ, BLOCK_FACE_EAST) || 
+					IsNotConnected(a_World, a_BlockX, a_BlockY, a_BlockZ, BLOCK_FACE_WEST)
+				)
+				{
+					return true;
+				}
+				break;
+			}
+			
+			case E_META_RAIL_ASCEND_XM:
+			{
+				if (
+					IsNotConnected(a_World, a_BlockX, a_BlockY, a_BlockZ, BLOCK_FACE_EAST) || 
+					IsNotConnected(a_World, a_BlockX, a_BlockY + 1, a_BlockZ, BLOCK_FACE_WEST)
+				)
+				{
+					return true;
+				}
+				break;
+			}
+			
+			case E_META_RAIL_ASCEND_ZM:
+			{
+				if (
+					IsNotConnected(a_World, a_BlockX, a_BlockY + 1, a_BlockZ, BLOCK_FACE_NORTH) || 
+					IsNotConnected(a_World, a_BlockX, a_BlockY, a_BlockZ, BLOCK_FACE_SOUTH)
+				)
+				{
+					return true;
+				}
+				break;
+			}
+			
+			case E_META_RAIL_ASCEND_ZP:
+			{
+				if (
+					IsNotConnected(a_World, a_BlockX, a_BlockY, a_BlockZ, BLOCK_FACE_NORTH) || 
+					IsNotConnected(a_World, a_BlockX, a_BlockY + 1, a_BlockZ, BLOCK_FACE_SOUTH)
+				)
+				{
+					return true;
+				}
+				break;
+			}
+			
+			case E_META_RAIL_CURVED_ZP_XP:
+			{
+				if (
+					IsNotConnected(a_World, a_BlockX, a_BlockY, a_BlockZ, BLOCK_FACE_SOUTH) || 
+					IsNotConnected(a_World, a_BlockX, a_BlockY, a_BlockZ, BLOCK_FACE_EAST)
+				)
+				{
+					return true;
+				}
+				break;
+			}
+			
+			case E_META_RAIL_CURVED_ZP_XM:
+			{
+				if (
+					IsNotConnected(a_World, a_BlockX, a_BlockY, a_BlockZ, BLOCK_FACE_SOUTH) || 
+					IsNotConnected(a_World, a_BlockX, a_BlockY, a_BlockZ, BLOCK_FACE_WEST)
+				)
+				{
+					return true;
+				}
+				break;
+			}
+			
+			case E_META_RAIL_CURVED_ZM_XM:
+			{
+				if (
+					IsNotConnected(a_World, a_BlockX, a_BlockY, a_BlockZ, BLOCK_FACE_NORTH) || 
+					IsNotConnected(a_World, a_BlockX, a_BlockY, a_BlockZ, BLOCK_FACE_WEST)
+				)
+				{
+					return true;
+				}
+				break;
+			}
+			
+			case E_META_RAIL_CURVED_ZM_XP:
+			{
+				if (
+					IsNotConnected(a_World, a_BlockX, a_BlockY, a_BlockZ, BLOCK_FACE_NORTH) || 
+					IsNotConnected(a_World, a_BlockX, a_BlockY, a_BlockZ, BLOCK_FACE_EAST)
+				)
+				{
+					return true;
+				}
+				break;
+			}
+		}
+		return false;
+	}
+
+
+	bool IsNotConnected(cWorld * a_World, int a_BlockX, int a_BlockY, int a_BlockZ, char a_BlockFace, char a_Pure = 0)
+	{
+		AddFaceDirection(a_BlockX, a_BlockY, a_BlockZ, a_BlockFace, false);
+		NIBBLETYPE Meta;
+		if (a_World->GetBlock(a_BlockX, a_BlockY, a_BlockZ) != E_BLOCK_RAIL)
+		{
+			if ((a_World->GetBlock(a_BlockX, a_BlockY + 1, a_BlockZ) != E_BLOCK_RAIL) || (a_Pure != E_PURE_UPDOWN))
+			{
+				if ((a_World->GetBlock(a_BlockX, a_BlockY - 1, a_BlockZ) != E_BLOCK_RAIL) || (a_Pure == E_PURE_NONE))
+				{
+					return true;
+				}
+				else
+				{
+					Meta = a_World->GetBlockMeta(a_BlockX, a_BlockY - 1, a_BlockZ);
+				}
+			}
+			else
+			{
+				Meta = a_World->GetBlockMeta(a_BlockX, a_BlockY + 1, a_BlockZ);
+			}
+		}
+		else
+		{
+			Meta = a_World->GetBlockMeta(a_BlockX, a_BlockY, a_BlockZ);
+		}
+		
+		switch (a_BlockFace)
+		{
+			case BLOCK_FACE_NORTH:
+			{
+				if (
+					(Meta == E_META_RAIL_ZM_ZP) ||
+					(Meta == E_META_RAIL_ASCEND_ZM) ||
+					(Meta == E_META_RAIL_ASCEND_ZP) ||
+					(Meta == E_META_RAIL_CURVED_ZP_XP) ||
+					(Meta == E_META_RAIL_CURVED_ZP_XM)
+				)
+				{
+					return false;
+				}
+				break;
+			}
+			
+			case BLOCK_FACE_SOUTH:
+			{
+				if (
+					(Meta == E_META_RAIL_ZM_ZP) ||
+					(Meta == E_META_RAIL_ASCEND_ZM) ||
+					(Meta == E_META_RAIL_ASCEND_ZP) ||
+					(Meta == E_META_RAIL_CURVED_ZM_XP) ||
+					(Meta == E_META_RAIL_CURVED_ZM_XM)
+				)
+				{
+					return false;
+				}
+				break;
+			}
+			
+			case BLOCK_FACE_EAST:
+			{
+				if (
+					(Meta == E_META_RAIL_XM_XP) ||
+					(Meta == E_META_RAIL_ASCEND_XP) ||
+					(Meta == E_META_RAIL_ASCEND_XM) ||
+					(Meta == E_META_RAIL_CURVED_ZP_XM) ||
+					(Meta == E_META_RAIL_CURVED_ZM_XM)
+				)
+				{
+					return false;
+				}
+				break;
+			}
+			case BLOCK_FACE_WEST:
+			{
+				if (
+					(Meta == E_META_RAIL_XM_XP) ||
+					(Meta == E_META_RAIL_ASCEND_XP) ||
+					(Meta == E_META_RAIL_ASCEND_XM) ||
+					(Meta == E_META_RAIL_CURVED_ZP_XP) ||
+					(Meta == E_META_RAIL_CURVED_ZM_XP)
+				)
+				{
+					return false;
+				}
+				break;
+			}
+		}
+		return true;
+	}
+} ;
+
+
+
+