1 files changed, 182 insertions, 2 deletions

diff --git a/source/Blocks/BlockFire.h b/source/Blocks/BlockFire.h
index d3ba499b1..0e98b17b5 100644
--- a/source/Blocks/BlockFire.h
+++ b/source/Blocks/BlockFire.h
@@ -16,6 +16,28 @@ public:
 	{
 	}
 
+	/// Portal boundary and direction variables
+	int XZP, XZM, Dir; // For wont of a better name...
+
+	virtual void OnPlaced(cWorld * a_World, int a_BlockX, int a_BlockY, int a_BlockZ, BLOCKTYPE a_BlockType, NIBBLETYPE a_BlockMeta) override
+	{
+		/*
+		PORTAL FINDING ALGORITH
+		=======================
+		-Get clicked base block
+		-Trace upwards to find first obsidian block; aborts if anything other than obsidian or air is encountered.
+		 Uses this value as a reference (the 'ceiling')
+		-For both directions (if one fails, try the other), BASE (clicked) block:
+		 -Go in one direction, only stop if a non obsidian block is encountered (abort) OR a portal border is encountered (FindObsidianCeiling returns -1)
+		 -If a border was encountered, go the other direction and repeat above
+		 -Write borders to XZP and XZM, write direction portal faces to Dir
+		-Loop through boundary variables, and fill with portal blocks based on Dir with meta from Dir		
+		*/
+
+		a_BlockY--; // Because we want the block below the fire
+		FindAndSetPortalFrame(a_BlockX, a_BlockY, a_BlockZ, a_World); // Brought to you by Aperture Science
+	}
+
 	virtual void OnDigging(cWorld * a_World, cPlayer * a_Player, int a_BlockX, int a_BlockY, int a_BlockZ) override
 	{
 		a_World->DigBlock(a_BlockX, a_BlockY, a_BlockZ);
@@ -30,12 +52,170 @@ public:
 	{
 		return true;
 	}
-	
+
 	virtual const char * GetStepSound(void) override
 	{
 		return "step.wood";
 	}
-} ;
+
+	/// Traces along YP until it finds an obsidian block, returns Y difference or 0 if no portal, and -1 for border
+	/// Takes the X, Y, and Z of the base block; with an optional MaxY for portal border finding
+	int FindObsidianCeiling(int X, int Y, int Z, NIBBLETYPE a_Dir, cWorld * a_World, int MaxY = 0)
+	{
+		if (a_World->GetBlock(X, Y, Z) != E_BLOCK_OBSIDIAN)
+		{
+			return 0;
+		}
+
+		int newY = Y + 1;
+
+		for (newY; newY < cChunkDef::Height; newY++)
+		{
+			BLOCKTYPE Block = a_World->GetBlock(X, newY, Z);
+			if ((Block == E_BLOCK_AIR) || (Block == E_BLOCK_FIRE))
+			{
+				continue;
+			}
+			else if (Block == E_BLOCK_OBSIDIAN)
+			{
+				// We found an obsidian ceiling
+				// Make sure MaxY has a value and newY ('ceiling' location) is at one above the base block
+				// This is because the frame is a solid obsidian pillar
+				if ((MaxY != 0) && (newY == Y + 1))
+				{
+					for (int checkBorder = newY + 1; checkBorder <= MaxY - 1; checkBorder++) // newY + 1: newY has already been checked; MaxY - 1: portal doesn't need corners
+					{
+						if (a_World->GetBlock(X, checkBorder, Z) != E_BLOCK_OBSIDIAN)
+						{
+							// Base obsidian, base + 1 obsidian, base + x NOT obsidian -> not complete portal
+							return 0;
+						}
+					}
+					// Everything was obsidian, found a border!
+					return 0 - 1; // Return -1 for a frame
+				}
+				else
+				{
+					// Return ceiling Y, whoever called this function will decide if it's part of a portal or not
+					return newY;
+				}
+			}
+			else { return 0; }
+		}
+
+		return 0;
+	}
+
+	/// Finds entire frame in any direction with the coordinates of a base block and fills hole with nether portal (START HERE)
+	void FindAndSetPortalFrame(int X, int Y, int Z, cWorld * a_World)
+	{
+		int MaxY = FindObsidianCeiling(X, Y, Z, 0, a_World); // Get topmost obsidian block as reference for all other checks; we don't know meta yet, so 0
+		int X1 = X + 1, Z1 = Z + 1, X2 = X - 1, Z2 = Z - 1; // Duplicate XZ values, add/subtract one as we've checked the original already the line above
+
+		if (MaxY == 0) // Oh noes! Not a portal coordinate :(
+		{
+			return;
+		}
+
+		if (!FindPortalSliceX(X1, X2, Y, Z, MaxY, a_World))
+		{
+			if (!FindPortalSliceZ(X, Y, Z1, Z2, MaxY, a_World))
+			{
+				return; // No eligible portal construct, abort abort abort!!
+			}
+		}
+
+		for (int Height = Y + 1; Height <= MaxY - 1; Height++) // Loop through boundary to set portal blocks
+		{
+			for (int Width = XZM; Width <= XZP; Width++)
+			{
+				if (Dir == 1)
+				{
+					a_World->SetBlock(Width, Height, Z, E_BLOCK_NETHER_PORTAL, Dir);
+				}
+				else
+				{
+					a_World->SetBlock(X, Height, Width, E_BLOCK_NETHER_PORTAL, Dir);
+				}
+			}
+		}
+
+		return;
+	}
+
+	/// Evaluates if coordinates are a portal going XP/XM; returns true if so, and writes boundaries to variable
+	/// Takes coordinates of base block and Y coord of target obsidian ceiling
+	bool FindPortalSliceX(int X1, int X2, int Y, int Z, int MaxY, cWorld * a_World)
+	{
+		Dir = 1; // Set assumed direction (will change if portal turns out to be facing the other direction)
+		bool FoundFrameXP = false, FoundFrameXM = false;
+		for (X1; ((a_World->GetBlock(X1, Y, Z) == E_BLOCK_OBSIDIAN) || (a_World->GetBlock(X1, Y + 1, Z) == E_BLOCK_OBSIDIAN)); X1++) // Check XP for obsidian blocks, exempting corners
+		{
+			int Value = FindObsidianCeiling(X1, Y, Z, 1, a_World, MaxY);
+			int ValueTwo = FindObsidianCeiling(X1, Y + 1, Z, 1, a_World, MaxY); // For corners without obsidian
+			if ((Value == 0 - 1) || (ValueTwo == 0 - 1)) // FindObsidianCeiling returns 0 - 1 upon frame-find
+			{
+				FoundFrameXP = true; // Found a frame border in this direction, proceed in other direction (don't go further)
+				break;
+			}
+			else if ((Value != MaxY) && (ValueTwo != MaxY)) // Make sure that there is a valid portal 'slice'
+			{
+				return false; // Not valid slice, no portal can be formed
+			}
+		} XZM = X1 - 2; // Set boundary of frame interior (hence the -2)
+		for (X2; ((a_World->GetBlock(X2, Y, Z) == E_BLOCK_OBSIDIAN) || (a_World->GetBlock(X2, Y + 1, Z) == E_BLOCK_OBSIDIAN)); X2--) // Go the other direction (XM)
+		{
+			int Value = FindObsidianCeiling(X2, Y, Z, 1, a_World, MaxY);
+			int ValueTwo = FindObsidianCeiling(X2, Y + 1, Z, 1, a_World, MaxY);
+			if ((Value == 0 - 1) || (ValueTwo == 0 - 1))
+			{
+				FoundFrameXM = true;
+				break;
+			}
+			else if ((Value != MaxY) && (ValueTwo != MaxY))
+			{
+				return false;
+			}
+		} XZP = X2 + 2; // Set boundary, see previous
+		return (FoundFrameXP && FoundFrameXM);
+	}
+
+	/// Evaluates if coords are a portal going ZP/ZM; returns true if so, and writes boundaries to variable
+	bool FindPortalSliceZ(int X, int Y, int Z1, int Z2, int MaxY, cWorld * a_World)
+	{
+		Dir = 2;
+		bool FoundFrameZP = false, FoundFrameZM = false;
+		for (Z1; ((a_World->GetBlock(X, Y, Z1) == E_BLOCK_OBSIDIAN) || (a_World->GetBlock(X, Y + 1, Z1) == E_BLOCK_OBSIDIAN)); Z1++)
+		{
+			int Value = FindObsidianCeiling(X, Y, Z1, 2, a_World, MaxY);
+			int ValueTwo = FindObsidianCeiling(X, Y + 1, Z1, 2, a_World, MaxY);
+			if ((Value == 0 - 1) || (ValueTwo == 0 - 1))
+			{
+				FoundFrameZP = true;
+				continue;
+			}
+			else if ((Value != MaxY) && (ValueTwo != MaxY))
+			{
+				return false;
+			}
+		} XZP = Z1 - 2;
+		for (Z2; ((a_World->GetBlock(X, Y, Z2) == E_BLOCK_OBSIDIAN) || (a_World->GetBlock(X, Y + 1, Z2) == E_BLOCK_OBSIDIAN)); Z2--)
+		{
+			int Value = FindObsidianCeiling(X, Y, Z2, 2, a_World, MaxY);
+			int ValueTwo = FindObsidianCeiling(X, Y + 1, Z2, 2, a_World, MaxY);
+			if ((Value == 0 - 1) || (ValueTwo == 0 - 1))
+			{
+				FoundFrameZM = true;
+				continue;
+			}
+			else if ((Value != MaxY) && (ValueTwo != MaxY))
+			{
+				return false;
+			}
+		} XZM = Z2 + 2;
+		return (FoundFrameZP && FoundFrameZM);
+	}
+};