Initial Floody fluid simulator.

Can spread, cannot dry.

git-svn-id: http://mc-server.googlecode.com/svn/trunk@963 0a769ca7-a7f5-676a-18bf-c427514a06d6

source/Simulator/FloodyFluidSimulator.cpp

@@ -0,0 +1,159 @@
+
+// FloodyFluidSimulator.cpp
+
+// Interfaces to the cFloodyFluidSimulator that represents a fluid simulator that tries to flood everything :)
+// http://forum.mc-server.org/showthread.php?tid=565
+
+#include "Globals.h"
+
+#include "FloodyFluidSimulator.h"
+#include "../World.h"
+#include "../BlockArea.h"
+#include "../Blocks/BlockHandler.h"
+
+
+
+
+
+cFloodyFluidSimulator::cFloodyFluidSimulator(cWorld * a_World, BLOCKTYPE a_Fluid, BLOCKTYPE a_StationaryFluid, NIBBLETYPE a_Falloff, int a_TickDelay) :
+	super(a_World, a_Fluid, a_StationaryFluid, a_TickDelay),
+	m_Falloff(a_Falloff)
+{
+}
+
+
+
+
+
+void cFloodyFluidSimulator::SimulateBlock(int a_BlockX, int a_BlockY, int a_BlockZ)
+{
+	cBlockArea Area;
+	int MinBlockY = std::max(0, a_BlockY - 1);
+	int MaxBlockY = std::min(cChunkDef::Height, a_BlockY + 1);
+	if (!Area.Read(m_World, a_BlockX - 1, a_BlockX + 1, MinBlockY, MaxBlockY, a_BlockZ - 1, a_BlockZ + 1))
+	{
+		// Cannot read the immediate neighborhood, probably too close to an unloaded chunk. Bail out.
+		// TODO: Shouldn't we re-schedule?
+		return;
+	}
+	int y = (a_BlockY > 0) ? 1 : 0;  // Relative y-coord of this block in Area
+	
+	NIBBLETYPE MyMeta = Area.GetRelBlockMeta(1, y, 1);
+
+	if (MyMeta != 0)
+	{
+		if (CheckTributaries(a_BlockX, a_BlockY, a_BlockZ, Area, MyMeta))
+		{
+			return;
+		}
+	}
+	
+	// New meta for the spreading to neighbors:
+	// If this is a source block or was falling, the new meta is just the falloff
+	// Otherwise it is the current meta plus falloff (may be larger than max height, will be checked later)
+	NIBBLETYPE NewMeta = ((MyMeta == 0) || ((MyMeta & 0x08) != 0)) ? m_Falloff : (MyMeta + m_Falloff);
+	
+	BLOCKTYPE Below = Area.GetRelBlockType(1, 0, 1);
+	if ((a_BlockY > 0) && IsPassableForFluid(Below))
+	{
+		// Spread only down, possibly washing away what's there:
+		SpreadToNeighbor(a_BlockX, a_BlockY - 1, a_BlockZ, Area, 8);
+	}
+	else if (NewMeta < 8)   // Can reach there
+	{
+		// Spread to the neighbors:
+		SpreadToNeighbor(a_BlockX - 1, a_BlockY, a_BlockZ,     Area, NewMeta);
+		SpreadToNeighbor(a_BlockX + 1, a_BlockY, a_BlockZ,     Area, NewMeta);
+		SpreadToNeighbor(a_BlockX,     a_BlockY, a_BlockZ - 1, Area, NewMeta);
+		SpreadToNeighbor(a_BlockX,     a_BlockY, a_BlockZ + 1, Area, NewMeta);
+	}
+	
+	// Mark as processed:
+	m_World->FastSetBlock(a_BlockX, a_BlockY, a_BlockZ, m_StationaryFluidBlock, MyMeta);
+}
+
+
+
+
+
+bool cFloodyFluidSimulator::CheckTributaries(int a_BlockX, int a_BlockY, int a_BlockZ, const cBlockArea & a_Area, NIBBLETYPE a_MyMeta)
+{
+	bool IsFed = false;
+	int y = (a_BlockY > 0) ? 1 : 0;  // Relative y-coord of this block in Area
+	
+	// If we have a section above, check if there's fluid above this block that would feed it:
+	if (a_BlockY < cChunkDef::Height - 1)
+	{
+		IsFed = IsAnyFluidBlock(a_Area.GetRelBlockType(1, 2, 1));
+	}
+
+	// If not fed from above, check if there's a feed from the side:
+	if (!IsFed)
+	{
+		IsFed = (
+			(IsAnyFluidBlock(a_Area.GetRelBlockType(0, y, 1)) && IsHigherMeta(a_Area.GetRelBlockMeta(0, y, 1), a_MyMeta)) ||
+			(IsAnyFluidBlock(a_Area.GetRelBlockType(2, y, 1)) && IsHigherMeta(a_Area.GetRelBlockMeta(2, y, 1), a_MyMeta)) ||
+			(IsAnyFluidBlock(a_Area.GetRelBlockType(1, y, 0)) && IsHigherMeta(a_Area.GetRelBlockMeta(1, y, 0), a_MyMeta)) ||
+			(IsAnyFluidBlock(a_Area.GetRelBlockType(1, y, 2)) && IsHigherMeta(a_Area.GetRelBlockMeta(1, y, 2), a_MyMeta))
+		);
+	}
+	
+	// If not fed, decrease by m_Falloff levels:
+	if (!IsFed)
+	{
+		a_MyMeta += m_Falloff;
+		if (a_MyMeta < 8)
+		{
+			m_World->SetBlock(a_BlockX, a_BlockY, a_BlockZ, m_StationaryFluidBlock, a_MyMeta);
+		}
+		else
+		{
+			m_World->SetBlock(a_BlockX, a_BlockY, a_BlockZ, E_BLOCK_AIR, 0);
+		}
+		return true;
+	}
+	return false;
+}
+
+
+
+
+
+void cFloodyFluidSimulator::SpreadToNeighbor(int a_BlockX, int a_BlockY, int a_BlockZ, const cBlockArea & a_Area, NIBBLETYPE a_NewMeta)
+{
+	BLOCKTYPE Block = a_Area.GetBlockType(a_BlockX, a_BlockY, a_BlockZ);
+	
+	if (IsAnyFluidBlock(Block))
+	{
+		NIBBLETYPE Meta = a_Area.GetBlockMeta(a_BlockX, a_BlockY, a_BlockZ);
+		if (!IsHigherMeta(a_NewMeta, Meta))
+		{
+			// Don't spread there, there's already a higher level there
+			return;
+		}
+	}
+	if (!IsPassableForFluid(Block))
+	{
+		// Can't spread there
+		return;
+	}
+	
+	// Wash away the block there, if possible:
+	if (CanWashAway(Block))
+	{
+		cBlockHandler * Handler = BlockHandler(Block);
+		if (Handler->DoesDropOnUnsuitable())
+		{
+			Handler->DropBlock(m_World, a_BlockX, a_BlockY, a_BlockZ);
+		}
+	}
+	
+	// Spread:
+	LOGD("Fluid:     spreading to block {%d, %d, %d}, meta %d", a_BlockX, a_BlockY, a_BlockZ, a_NewMeta);
+	
+	m_World->SetBlock(a_BlockX, a_BlockY, a_BlockZ, m_FluidBlock, a_NewMeta);
+}
+
+
+
+