5 files changed, 56 insertions, 9 deletions

diff --git a/src/BlockEntities/DropSpenserEntity.h b/src/BlockEntities/DropSpenserEntity.h
index 9f58d0b07..dabe9a27b 100644
--- a/src/BlockEntities/DropSpenserEntity.h
+++ b/src/BlockEntities/DropSpenserEntity.h
@@ -11,7 +11,7 @@
 #pragma once
 
 #include "BlockEntityWithItems.h"
-
+#include "RedstonePoweredEntity.h"
 
 
 
@@ -30,7 +30,8 @@ class cServer;
 
 // tolua_begin
 class cDropSpenserEntity :
-	public cBlockEntityWithItems
+	public cBlockEntityWithItems,
+	public cRedstonePoweredEntity
 {
 	typedef cBlockEntityWithItems super;
 
@@ -65,7 +66,7 @@ public:
 	void Activate(void);
 	
 	/// Sets the internal redstone power flag to "on" or "off", depending on the parameter. Calls Activate() if appropriate
-	void SetRedstonePower(bool a_IsPowered);
+	virtual void SetRedstonePower(bool a_IsPowered) override;
 	
 	// tolua_end
 
diff --git a/src/BlockEntities/RedstonePoweredEntity.h b/src/BlockEntities/RedstonePoweredEntity.h
new file mode 100644
index 000000000..aebba771f
--- /dev/null
+++ b/src/BlockEntities/RedstonePoweredEntity.h
@@ -0,0 +1,9 @@
+
+
+// Interface class representing a blockEntity that responds to redstone
+class cRedstonePoweredEntity
+{
+public:
+/// Sets the internal redstone power flag to "on" or "off", depending on the parameter. Calls Activate() if appropriate
+	virtual void SetRedstonePower(bool a_IsPowered) = 0;
+};
diff --git a/src/Chunk.cpp b/src/Chunk.cpp
index cd7dc698c..9e06f58ec 100644
--- a/src/Chunk.cpp
+++ b/src/Chunk.cpp
@@ -2127,6 +2127,40 @@ bool cChunk::DoWithBlockEntityAt(int a_BlockX, int a_BlockY, int a_BlockZ, cBloc
 
 
 
+bool cChunk::DoWithRedstonePoweredEntityAt(int a_BlockX, int a_BlockY, int a_BlockZ, cRedstonePoweredCallback & a_Callback)
+{
+	// The blockentity list is locked by the parent chunkmap's CS
+	for (cBlockEntityList::iterator itr = m_BlockEntities.begin(), itr2 = itr; itr != m_BlockEntities.end(); itr = itr2)
+	{
+		++itr2;
+		if (((*itr)->GetPosX() != a_BlockX) || ((*itr)->GetPosY() != a_BlockY) || ((*itr)->GetPosZ() != a_BlockZ))
+		{
+			continue;
+		}
+		switch ((*itr)->GetBlockType())
+		{
+			case E_BLOCK_DROPPER:
+			case E_BLOCK_DISPENSER:
+			break;
+			default:
+			// There is a block entity here, but of different type. No other block entity can be here, so we can safely bail out
+			return false;
+		}
+		
+		if (a_Callback.Item((cRedstonePoweredEntity *)*itr))
+		{
+			return false;
+		}
+		return true;
+	}  // for itr - m_BlockEntitites[]
+	
+	// Not found:
+	return false;
+}
+
+
+
+
 bool cChunk::DoWithBeaconAt(int a_BlockX, int a_BlockY, int a_BlockZ, cBeaconCallback & a_Callback)
 {
 	// The blockentity list is locked by the parent chunkmap's CS
diff --git a/src/Chunk.h b/src/Chunk.h
index 5cde3f08f..813a8b13f 100644
--- a/src/Chunk.h
+++ b/src/Chunk.h
@@ -43,6 +43,7 @@ class cBlockArea;
 class cFluidSimulatorData;
 class cMobCensus;
 class cMobSpawner;
+class cRedstonePoweredEntity;
 
 typedef std::list<cClientHandle *>         cClientHandleList;
 typedef cItemCallback<cEntity>             cEntityCallback;
@@ -54,6 +55,7 @@ typedef cItemCallback<cNoteEntity>         cNoteBlockCallback;
 typedef cItemCallback<cCommandBlockEntity> cCommandBlockCallback;
 typedef cItemCallback<cMobHeadEntity>      cMobHeadCallback;
 typedef cItemCallback<cFlowerPotEntity>    cFlowerPotCallback;
+typedef cItemCallback<cRedstonePoweredEntity> cRedstonePoweredCallback;
 
 
 
@@ -237,7 +239,9 @@ public:
 	
 	/** Calls the callback for the block entity at the specified coords; returns false if there's no block entity at those coords, true if found */
 	bool DoWithBlockEntityAt(int a_BlockX, int a_BlockY, int a_BlockZ, cBlockEntityCallback & a_Callback);  // Lua-acessible
-
+	
+	/** Calls the callback for the redstone powered entity at the specified coords; returns false if there's no redstone powered entity at those coords, true if found */
+	bool DoWithRedstonePoweredEntityAt(int a_BlockX, int a_BlockY, int a_BlockZ, cRedstonePoweredCallback & a_Callback);  
 	/** Calls the callback for the beacon at the specified coords; returns false if there's no beacon at those coords, true if found */
 	bool DoWithBeaconAt(int a_BlockX, int a_BlockY, int a_BlockZ, cBeaconCallback & a_Callback);  // Lua-acessible
 
diff --git a/src/Simulator/IncrementalRedstoneSimulator.cpp b/src/Simulator/IncrementalRedstoneSimulator.cpp
index c1a2fcaae..5b2439db1 100644
--- a/src/Simulator/IncrementalRedstoneSimulator.cpp
+++ b/src/Simulator/IncrementalRedstoneSimulator.cpp
@@ -3,11 +3,10 @@
 
 #include "IncrementalRedstoneSimulator.h"
 #include "BoundingBox.h"
-#include "../BlockEntities/DropSpenserEntity.h"
+#include "../BlockEntities/RedstonePoweredEntity.h"
 #include "../BlockEntities/NoteEntity.h"
 #include "../BlockEntities/ChestEntity.h"
 #include "../BlockEntities/CommandBlockEntity.h"
-#include "../Entities/TNTEntity.h"
 #include "../Entities/Pickup.h"
 #include "../Blocks/BlockTorch.h"
 #include "../Blocks/BlockDoor.h"
@@ -842,13 +841,13 @@ void cIncrementalRedstoneSimulator::HandlePiston(int a_RelBlockX, int a_RelBlock
 void cIncrementalRedstoneSimulator::HandleDropSpenser(int a_RelBlockX, int a_RelBlockY, int a_RelBlockZ)
 {
 	class cSetPowerToDropSpenser :
-		public cDropSpenserCallback
+		public cRedstonePoweredCallback
 	{
 		bool m_IsPowered;
 	public:
 		cSetPowerToDropSpenser(bool a_IsPowered) : m_IsPowered(a_IsPowered) {}
 
-		virtual bool Item(cDropSpenserEntity * a_DropSpenser) override
+		virtual bool Item(cRedstonePoweredEntity * a_DropSpenser) override
 		{
 			a_DropSpenser->SetRedstonePower(m_IsPowered);
 			return false;
@@ -857,7 +856,7 @@ void cIncrementalRedstoneSimulator::HandleDropSpenser(int a_RelBlockX, int a_Rel
 
 	int BlockX = (m_Chunk->GetPosX() * cChunkDef::Width) + a_RelBlockX;
 	int BlockZ = (m_Chunk->GetPosZ() * cChunkDef::Width) + a_RelBlockZ;
-	m_Chunk->DoWithDropSpenserAt(BlockX, a_RelBlockY, BlockZ, DrSpSP);
+	m_Chunk->DoWithRedstonePoweredEntityAt(BlockX, a_RelBlockY, BlockZ, DrSpSP);
 }