1 files changed, 291 insertions, 0 deletions

diff --git a/src/Piston.cpp b/src/Piston.cpp
new file mode 100644
index 000000000..048cc355d
--- /dev/null
+++ b/src/Piston.cpp
@@ -0,0 +1,291 @@
+#include "Globals.h"  // NOTE: MSVC stupidness requires this to be the same across all modules
+
+#include "Piston.h"
+#include "ChunkDef.h"
+#include "Entities/Pickup.h"
+#include "Item.h"
+#include "Root.h"
+#include "ClientHandle.h"
+#include "World.h"
+#include "Server.h"
+#include "Blocks/BlockHandler.h"
+
+
+
+
+
+/// Number of ticks that the piston extending / retracting waits before setting the block
+const int PISTON_TICK_DELAY = 6;
+
+
+
+
+
+cPiston::cPiston(cWorld * a_World)
+	: m_World(a_World)
+{
+
+}
+
+
+
+
+
+int cPiston::FirstPassthroughBlock(int pistonX, int pistonY, int pistonZ, NIBBLETYPE pistonmeta)
+{
+	// Examine each of the 12 blocks ahead of the piston:
+	for (int ret = 0; ret < 12; ret++)
+	{
+		BLOCKTYPE currBlock;
+		NIBBLETYPE currMeta;
+		AddDir(pistonX, pistonY, pistonZ, pistonmeta, 1);
+		m_World->GetBlockTypeMeta(pistonX, pistonY, pistonZ, currBlock, currMeta);
+		if (CanBreakPush(currBlock, currMeta))
+		{
+			// This block breaks when pushed, extend up to here
+			return ret;
+		}
+		if (!CanPush(currBlock, currMeta))
+		{
+			// This block cannot be pushed at all, the piston can't extend
+			return -1;
+		}
+	}
+	// There is no space for the blocks to move, piston can't extend
+	return -1;
+}
+
+
+
+
+
+void cPiston::ExtendPiston(int pistx, int pisty, int pistz)
+{
+	BLOCKTYPE pistonBlock;
+	NIBBLETYPE pistonMeta;
+	m_World->GetBlockTypeMeta(pistx, pisty, pistz, pistonBlock, pistonMeta);
+	
+	if (IsExtended(pistonMeta))
+	{
+		// Already extended, bail out
+		return;
+	}
+
+	int dist = FirstPassthroughBlock(pistx, pisty, pistz, pistonMeta);
+	if (dist < 0)
+	{
+		// FirstPassthroughBlock says piston can't push anything, bail out
+		return;
+	}
+
+	m_World->BroadcastBlockAction(pistx, pisty, pistz, 0, pistonMeta, pistonBlock);
+	m_World->BroadcastSoundEffect("tile.piston.out", pistx * 8, pisty * 8, pistz * 8, 0.5f, 0.7f);	
+	
+	// Drop the breakable block in the line, if appropriate:
+	AddDir(pistx, pisty, pistz, pistonMeta, dist + 1);  // "pist" now at the breakable / empty block
+	BLOCKTYPE currBlock;
+	NIBBLETYPE currMeta;
+	m_World->GetBlockTypeMeta(pistx, pisty, pistz, currBlock, currMeta);
+	if (currBlock != E_BLOCK_AIR)
+	{
+		cBlockHandler * Handler = BlockHandler(currBlock);
+		if (Handler->DoesDropOnUnsuitable())
+		{
+			Handler->DropBlock(m_World, NULL, pistx, pisty, pistz);
+		}
+	}
+	
+	// Push blocks, from the furthest to the nearest:
+	int oldx = pistx, oldy = pisty, oldz = pistz;
+	NIBBLETYPE currBlockMeta;
+	for (int i = dist + 1; i > 1; i--)
+	{
+		AddDir(pistx, pisty, pistz, pistonMeta, -1);
+		m_World->GetBlockTypeMeta(pistx, pisty, pistz, currBlock, currBlockMeta);
+		m_World->QueueSetBlock( oldx, oldy, oldz, currBlock, currBlockMeta, PISTON_TICK_DELAY);
+		oldx = pistx;
+		oldy = pisty;
+		oldz = pistz;
+	}
+
+	int extx = pistx;
+	int exty = pisty;
+	int extz = pistz;
+	AddDir(pistx, pisty, pistz, pistonMeta, -1);
+	// "pist" now at piston body, "ext" at future extension
+	
+	m_World->SetBlock( pistx, pisty, pistz, pistonBlock, pistonMeta | 0x8);
+	m_World->QueueSetBlock(extx, exty, extz, E_BLOCK_PISTON_EXTENSION, pistonMeta | (IsSticky(pistonBlock) ? 8 : 0), PISTON_TICK_DELAY);
+}
+
+
+
+
+
+void cPiston::RetractPiston(int pistx, int pisty, int pistz)
+{
+	BLOCKTYPE pistonBlock;
+	NIBBLETYPE pistonMeta;
+	m_World->GetBlockTypeMeta(pistx, pisty, pistz, pistonBlock, pistonMeta);
+	if (!IsExtended(pistonMeta))
+	{
+		// Already retracted, bail out
+		return;
+	}
+	
+	m_World->BroadcastBlockAction(pistx, pisty, pistz, 1, pistonMeta & ~(8), pistonBlock);
+	m_World->BroadcastSoundEffect("tile.piston.in", pistx * 8, pisty * 8, pistz * 8, 0.5f, 0.7f);			
+	m_World->SetBlock(pistx, pisty, pistz, pistonBlock, pistonMeta & ~(8));
+
+	// Check the extension:
+	AddDir(pistx, pisty, pistz, pistonMeta, 1);
+	if (m_World->GetBlock(pistx, pisty, pistz) != E_BLOCK_PISTON_EXTENSION)
+	{
+		LOGD("%s: Piston without an extension?", __FUNCTION__);
+		return;
+	}
+	
+	// Retract the extension, pull block if appropriate
+	if (IsSticky(pistonBlock))
+	{
+		int tempx = pistx, tempy = pisty, tempz = pistz;
+		AddDir( tempx, tempy, tempz, pistonMeta, 1);
+		BLOCKTYPE tempBlock;
+		NIBBLETYPE tempMeta;
+		m_World->GetBlockTypeMeta(tempx, tempy, tempz, tempBlock, tempMeta);
+		if (CanPull(tempBlock, tempMeta))
+		{
+			// Pull the block
+			m_World->QueueSetBlock(pistx, pisty, pistz, tempBlock, tempMeta, PISTON_TICK_DELAY);
+			m_World->QueueSetBlock(tempx, tempy, tempz, E_BLOCK_AIR, 0, PISTON_TICK_DELAY);
+		}
+		else
+		{
+			// Retract without pulling
+			m_World->QueueSetBlock(pistx, pisty, pistz, E_BLOCK_AIR, 0, PISTON_TICK_DELAY);
+		}
+	}
+	else
+	{
+		m_World->QueueSetBlock(pistx, pisty, pistz, E_BLOCK_AIR, 0, PISTON_TICK_DELAY);
+	}
+}
+
+
+
+
+
+bool cPiston::IsExtended(NIBBLETYPE a_PistonMeta)
+{
+	return ((a_PistonMeta & 0x8) != 0x0);
+}
+
+
+
+
+
+bool cPiston::IsSticky(BLOCKTYPE a_BlockType)
+{
+	return (a_BlockType == E_BLOCK_STICKY_PISTON);
+}
+
+
+
+
+
+bool cPiston::CanPush(BLOCKTYPE a_BlockType, NIBBLETYPE a_BlockMeta)
+{
+	switch (a_BlockType)
+	{
+		case E_BLOCK_ANVIL:
+		case E_BLOCK_BED:
+		case E_BLOCK_BEDROCK:
+		case E_BLOCK_BREWING_STAND:
+		case E_BLOCK_CHEST:
+		case E_BLOCK_COMMAND_BLOCK:
+		case E_BLOCK_DISPENSER:
+		case E_BLOCK_DROPPER:
+		case E_BLOCK_ENCHANTMENT_TABLE:
+		case E_BLOCK_END_PORTAL:
+		case E_BLOCK_END_PORTAL_FRAME:
+		case E_BLOCK_FURNACE:
+		case E_BLOCK_LIT_FURNACE:
+		case E_BLOCK_HOPPER:
+		case E_BLOCK_JUKEBOX:
+		case E_BLOCK_MOB_SPAWNER:
+		case E_BLOCK_NETHER_PORTAL:
+		case E_BLOCK_NOTE_BLOCK:
+		case E_BLOCK_OBSIDIAN:
+		case E_BLOCK_PISTON_EXTENSION:
+		{
+			return false;
+		}
+		case E_BLOCK_STICKY_PISTON:
+		case E_BLOCK_PISTON:
+		{
+			// A piston can only be pushed if retracted:
+			return !IsExtended(a_BlockMeta);
+		}
+	}
+	return true;
+}
+
+
+
+
+
+bool cPiston::CanBreakPush(BLOCKTYPE a_BlockType, NIBBLETYPE a_BlockMeta)
+{
+	return g_BlockPistonBreakable[a_BlockType];
+}
+
+
+
+
+
+bool cPiston::CanPull(BLOCKTYPE a_BlockType, NIBBLETYPE a_BlockMeta)
+{
+	switch (a_BlockType)
+	{
+		case E_BLOCK_LAVA:
+		case E_BLOCK_STATIONARY_LAVA:
+		case E_BLOCK_STATIONARY_WATER:
+		case E_BLOCK_WATER:
+		{
+			return false;
+		}
+	}
+
+	if (CanBreakPush(a_BlockType, a_BlockMeta))
+	{
+		return false; // CanBreakPush returns true, but we need false to prevent pulling
+	}
+
+	return CanPush(a_BlockType, a_BlockMeta);
+}
+
+
+
+
+
+void cPiston::AddDir(int & a_BlockX, int & a_BlockY, int & a_BlockZ, NIBBLETYPE a_PistonMeta, int a_Amount)
+{
+	switch (a_PistonMeta & 0x07)
+	{
+		case 0: a_BlockY -= a_Amount; break;
+		case 1: a_BlockY += a_Amount; break;
+		case 2: a_BlockZ -= a_Amount; break;
+		case 3: a_BlockZ += a_Amount; break;
+		case 4: a_BlockX -= a_Amount; break;
+		case 5: a_BlockX += a_Amount; break;
+		default:
+		{
+			LOGWARNING("%s: invalid direction %d, ignoring", __FUNCTION__, a_PistonMeta & 0x07);
+			break;
+		}
+	}
+}
+
+
+
+