cuberite-2a/source/cPiston.cpp

#include "cPiston.h"
#include "cRedstone.h"
#include "cChunk.h"
#include "cPickup.h"
#include "cBlockToPickup.h"
#include "cItem.h"
#include "cRoot.h"
#include "cClientHandle.h"
#include "cWorld.h"
#include "BlockID.h"
#include "packets/cPacket_BlockAction.h"
#include "cServer.h"

extern bool g_BlockPistonBreakable[];

#define AddDir( x, y, z, dir, amount ) switch(dir) { case 0: (y)-=(amount); break; case 1: (y)+=(amount); break;\
													 case 2: (z)-=(amount); break; case 3: (z)+=(amount); break;\
													 case 4: (x)-=(amount); break; case 5: (x)+=(amount); break; }

#define FAST_FLOOR( x ) ( (x) < 0 ? ((int)x)-1 : ((int)x) )

cPiston::cPiston( cWorld* a_World )
	:m_World ( a_World )
{

}

unsigned short cPiston::FirstPassthroughBlock( int pistonX, int pistonY, int pistonZ, char pistonmeta ) {
	unsigned short ret;
	pistonmeta &= 7;
	if(pistonmeta >= 6) { // just in case, it shouldn't happen but if it would, it'd case inf loop
		printf("cPiston::FirstPassthroughBlock - piston has invalid meta data!\n");
		return 9001;
	}
	char currBlock;
	for( ret = 0; ret < 24; ret++ ) { // push up to 24 blocks
		AddDir( pistonX, pistonY, pistonZ, pistonmeta, 1 )
		currBlock = m_World->GetBlock( pistonX, pistonY, pistonZ );
		if(currBlock == E_BLOCK_BEDROCK || currBlock == E_BLOCK_OBSIDIAN || currBlock == E_BLOCK_PISTON_EXTENSION ) {return 9001;}
		if(g_BlockPistonBreakable[currBlock]) {return ret;}
	}
	return 9001;
}

void cPiston::ExtendPiston( int pistx, int pisty, int pistz ) {
	char pistonBlock = m_World->GetBlock( pistx, pisty, pistz );
	char pistonMeta = m_World->GetBlockMeta( pistx, pisty, pistz );
	char isSticky = (char)(pistonBlock == E_BLOCK_STICKY_PISTON) * 8;
	bool recalc = false;
	if (pistonMeta < 6) {// only extend if piston is not already extended 
		unsigned short dist = FirstPassthroughBlock(pistx, pisty, pistz, pistonMeta);
		if(dist>9000) return; // too many blocks
	
		AddDir( pistx, pisty, pistz, pistonMeta & 7, dist+1 )
		char currBlock = m_World->GetBlock( pistx, pisty, pistz );
		if( currBlock != E_BLOCK_AIR ) {
			cItem PickupItem;
			PickupItem.m_ItemID = cBlockToPickup::ToPickup( (ENUM_BLOCK_ID) currBlock, E_ITEM_EMPTY );
			PickupItem.m_ItemCount = 1;
			cPickup* Pickup = new cPickup( pistx*32 + 16, pisty*32 + 16, pistz*32 + 16, PickupItem );
			Pickup->Initialize( m_World );
			recalc = true;
		}
		int oldx = pistx, oldy = pisty, oldz = pistz;
		char currBlockMeta;
		for( int i = dist+1; i>0; i-- ) {
			AddDir( pistx, pisty, pistz, pistonMeta & 7, -1 )
			currBlock = m_World->GetBlock( pistx, pisty, pistz );
			currBlockMeta = m_World->GetBlockMeta( pistx, pisty, pistz );
			m_World->SetBlock( oldx, oldy, oldz, currBlock, currBlockMeta );
			oldx = pistx;
			oldy = pisty;
			oldz = pistz;
		}
		cPacket_BlockAction Action;
		Action.m_PosX		= (int)pistx;
		Action.m_PosY		= (short)pisty;
		Action.m_PosZ		= (int)pistz;
		Action.m_Byte1	=	0;
		Action.m_Byte2	=	pistonMeta;

		
		cChunk* Chunk 	= m_World->GetChunk( FAST_FLOOR(pistx/16), FAST_FLOOR(pisty/16), FAST_FLOOR(pistz/16)  );
		Chunk->Broadcast( Action );
		m_World->FastSetBlock( pistx, pisty, pistz, pistonBlock, pistonMeta | 8 );

		int extx = pistx;
		int exty = pisty;
		int extz = pistz;
	
		AddDir( extx, exty, extz, pistonMeta&7, 1 )

		m_World->SetBlock( extx, exty, extz, E_BLOCK_PISTON_EXTENSION, isSticky+pistonMeta&7 );
		
		if (recalc) {
			cRedstone Redstone(m_World);
			Redstone.ChangeRedstone( extx, exty, extz, false ); //recalculate redstone around current device.			
			Redstone.ChangeRedstone( pistx, pisty, pistz, false ); //recalculate redstone around current device.			
		}

	}

}

void cPiston::RetractPiston( int pistx, int pisty, int pistz ) {
	char pistonBlock = m_World->GetBlock( pistx, pisty, pistz );
	char pistonMeta = m_World->GetBlockMeta( pistx, pisty, pistz );
	if (pistonMeta > 6) {// only retract if piston is not already retracted
		//send blockaction packet
		cPacket_BlockAction Action;
		Action.m_PosX		= (int)pistx;
		Action.m_PosY		= (short)pisty;
		Action.m_PosZ		= (int)pistz;
		Action.m_Byte1	=	1;
		Action.m_Byte2	=	pistonMeta & ~(8);
		cChunk* Chunk 	= m_World->GetChunk( FAST_FLOOR(pistx/16), FAST_FLOOR(pisty/16), FAST_FLOOR(pistz/16) );
		Chunk->Broadcast( Action );
		m_World->FastSetBlock( pistx, pisty, pistz, pistonBlock, pistonMeta & ~(8) );
		
		AddDir( pistx, pisty, pistz, pistonMeta & 7, 1 )
		if( m_World->GetBlock( pistx, pisty, pistz ) == E_BLOCK_PISTON_EXTENSION ) {
			if( pistonBlock == E_BLOCK_STICKY_PISTON ) {
				int tempx = pistx, tempy = pisty, tempz = pistz;
				AddDir( tempx, tempy, tempz, pistonMeta&7, 1 )
				char tempblock = m_World->GetBlock( tempx, tempy, tempz );
				if(tempblock == E_BLOCK_OBSIDIAN || tempblock == E_BLOCK_BEDROCK || tempblock == E_BLOCK_PISTON_EXTENSION) {return;}
				m_World->SetBlock( pistx, pisty, pistz, tempblock, m_World->GetBlockMeta( tempx, tempy, tempz ) );
				m_World->SetBlock( tempx, tempy, tempz, E_BLOCK_AIR, 0 );
			}else{
				m_World->SetBlock( pistx, pisty, pistz, E_BLOCK_AIR, 0 );
			}
		}
	}
}