13 files changed, 172 insertions, 4 deletions

diff --git a/Server/Plugins/APIDump/Classes/World.lua b/Server/Plugins/APIDump/Classes/World.lua
index eb0e0d17d..c35733b4a 100644
--- a/Server/Plugins/APIDump/Classes/World.lua
+++ b/Server/Plugins/APIDump/Classes/World.lua
@@ -939,6 +939,35 @@ function OnAllChunksAvailable()</pre> All return values from the callbacks are i
 				},
 				Notes = "If there is a furnace at the specified coords, calls the CallbackFunction with the {{cFurnaceEntity}} parameter representing the furnace. The CallbackFunction has the following signature: <pre class=\"prettyprint lang-lua\">function Callback({{cFurnaceEntity|FurnaceEntity}})</pre> The function returns false if there is no furnace, or if there is, it returns the bool value that the callback has returned.",
 			},
+			DoWithHopperAt =
+			{
+				Params =
+				{
+					{
+						Name = "BlockX",
+						Type = "number",
+					},
+					{
+						Name = "BlockY",
+						Type = "number",
+					},
+					{
+						Name = "BlockZ",
+						Type = "number",
+					},
+					{
+						Name = "CallbackFunction",
+						Type = "function",
+					},
+				},
+				Returns =
+				{
+					{
+						Type = "boolean",
+					},
+				},
+				Notes = "If there is a hopper at the specified coords, calls the CallbackFunction with the {{cHopperEntity}} parameter representing the hopper. The CallbackFunction has the following signature: <pre class=\"prettyprint lang-lua\">function Callback({{cHopperEntity|cHopperEntity}})</pre> The function returns false if there is no hopper, or if there is, it returns the bool value that the callback has returned.",
+			},
 			DoWithMobHeadAt =
 			{
 				Params =
diff --git a/src/Bindings/ManualBindings_World.cpp b/src/Bindings/ManualBindings_World.cpp
index 17a66b4c2..7b072e435 100644
--- a/src/Bindings/ManualBindings_World.cpp
+++ b/src/Bindings/ManualBindings_World.cpp
@@ -984,6 +984,7 @@ void cManualBindings::BindWorld(lua_State * tolua_S)
 			tolua_function(tolua_S, "DoWithEntityByID",             DoWithID< cWorld, cEntity,             &cWorld::DoWithEntityByID>);
 			tolua_function(tolua_S, "DoWithFlowerPotAt",            DoWithXYZ<cWorld, cFlowerPotEntity,    &cWorld::DoWithFlowerPotAt>);
 			tolua_function(tolua_S, "DoWithFurnaceAt",              DoWithXYZ<cWorld, cFurnaceEntity,      &cWorld::DoWithFurnaceAt>);
+			tolua_function(tolua_S, "DoWithHopperAt",               DoWithXYZ<cWorld, cHopperEntity,       &cWorld::DoWithHopperAt>);
 			tolua_function(tolua_S, "DoWithMobHeadAt",              DoWithXYZ<cWorld, cMobHeadEntity,      &cWorld::DoWithMobHeadAt>);
 			tolua_function(tolua_S, "DoWithNearestPlayer",          tolua_cWorld_DoWithNearestPlayer);
 			tolua_function(tolua_S, "DoWithNoteBlockAt",            DoWithXYZ<cWorld, cNoteEntity,         &cWorld::DoWithNoteBlockAt>);
diff --git a/src/BlockEntities/HopperEntity.cpp b/src/BlockEntities/HopperEntity.cpp
index e85cfb952..aadca8311 100644
--- a/src/BlockEntities/HopperEntity.cpp
+++ b/src/BlockEntities/HopperEntity.cpp
@@ -20,7 +20,8 @@
 cHopperEntity::cHopperEntity(BLOCKTYPE a_BlockType, NIBBLETYPE a_BlockMeta, Vector3i a_Pos, cWorld * a_World):
 	super(a_BlockType, a_BlockMeta, a_Pos, ContentsWidth, ContentsHeight, a_World),
 	m_LastMoveItemsInTick(0),
-	m_LastMoveItemsOutTick(0)
+	m_LastMoveItemsOutTick(0),
+	m_Locked(false)
 {
 	ASSERT(a_BlockType == E_BLOCK_HOPPER);
 }
@@ -29,6 +30,15 @@ cHopperEntity::cHopperEntity(BLOCKTYPE a_BlockType, NIBBLETYPE a_BlockMeta, Vect
 
 
 
+void cHopperEntity::SetLocked(bool a_Value)
+{
+	m_Locked = a_Value;
+}
+
+
+
+
+
 std::pair<bool, Vector3i> cHopperEntity::GetOutputBlockPos(NIBBLETYPE a_BlockMeta)
 {
 	auto pos = GetPos();
@@ -69,9 +79,12 @@ bool cHopperEntity::Tick(std::chrono::milliseconds a_Dt, cChunk & a_Chunk)
 	Int64 CurrentTick = a_Chunk.GetWorld()->GetWorldAge();
 
 	bool isDirty = false;
-	isDirty = MoveItemsIn  (a_Chunk, CurrentTick) || isDirty;
-	isDirty = MovePickupsIn(a_Chunk, CurrentTick) || isDirty;
-	isDirty = MoveItemsOut (a_Chunk, CurrentTick) || isDirty;
+	if (!m_Locked)
+	{
+		isDirty = MoveItemsIn  (a_Chunk, CurrentTick) || isDirty;
+		isDirty = MovePickupsIn(a_Chunk, CurrentTick) || isDirty;
+		isDirty = MoveItemsOut (a_Chunk, CurrentTick) || isDirty;
+	}
 	return isDirty;
 }
 
diff --git a/src/BlockEntities/HopperEntity.h b/src/BlockEntities/HopperEntity.h
index c57dce672..ef86a36bb 100644
--- a/src/BlockEntities/HopperEntity.h
+++ b/src/BlockEntities/HopperEntity.h
@@ -33,6 +33,8 @@ public:
 		TICKS_PER_TRANSFER = 8,  ///< How many ticks at minimum between two item transfers to or from the hopper
 	} ;
 
+
+
 	// tolua_end
 
 	BLOCKENTITY_PROTODEF(cHopperEntity)
@@ -45,6 +47,8 @@ public:
 	Exported in ManualBindings.cpp. */
 	std::pair<bool, Vector3i> GetOutputBlockPos(NIBBLETYPE a_BlockMeta);
 
+	void SetLocked(bool a_Value);
+
 protected:
 
 	Int64 m_LastMoveItemsInTick;
@@ -91,6 +95,10 @@ protected:
 
 	/** Moves one piece to the specified entity's contents' slot. Returns true if contents have changed. */
 	bool MoveItemsToSlot(cBlockEntityWithItems & a_Entity, int a_DstSlotNum);
+
+private:
+
+	bool m_Locked;
 } ;  // tolua_export
 
 
diff --git a/src/Chunk.cpp b/src/Chunk.cpp
index 574c00132..9dc0e8aee 100644
--- a/src/Chunk.cpp
+++ b/src/Chunk.cpp
@@ -2177,6 +2177,17 @@ bool cChunk::DoWithFurnaceAt(int a_BlockX, int a_BlockY, int a_BlockZ, cFurnaceC
 
 
 
+bool cChunk::DoWithHopperAt(int a_BlockX, int a_BlockY, int a_BlockZ, cHopperCallback a_Callback)
+{
+	return GenericDoWithBlockEntityAt<cHopperEntity,
+		E_BLOCK_HOPPER
+	>(a_BlockX, a_BlockY, a_BlockZ, a_Callback);
+}
+
+
+
+
+
 bool cChunk::DoWithNoteBlockAt(int a_BlockX, int a_BlockY, int a_BlockZ, cNoteBlockCallback a_Callback)
 {
 	return GenericDoWithBlockEntityAt<cNoteEntity,
diff --git a/src/Chunk.h b/src/Chunk.h
index 9aa963fae..dd21d0e8f 100644
--- a/src/Chunk.h
+++ b/src/Chunk.h
@@ -27,6 +27,7 @@ class cChunkDataCallback;
 class cCommandBlockEntity;
 class cDispenserEntity;
 class cFurnaceEntity;
+class cHopperEntity;
 class cNoteEntity;
 class cMobHeadEntity;
 class cFlowerPotEntity;
@@ -332,6 +333,9 @@ public:
 	/** Calls the callback for the furnace at the specified coords; returns false if there's no furnace at those coords or callback returns true, returns true if found */
 	bool DoWithFurnaceAt(int a_BlockX, int a_BlockY, int a_BlockZ, cFurnaceCallback a_Callback);  // Lua-accessible
 
+	/** Calls the callback for the hopper at the specified coords; returns false if there's no hopper at those coords or callback returns true, returns true if found */
+	bool DoWithHopperAt(int a_BlockX, int a_BlockY, int a_BlockZ, cHopperCallback a_Callback);  // Lua-accessible
+
 	/** Calls the callback for the noteblock at the specified coords; returns false if there's no noteblock at those coords or callback returns true, returns true if found */
 	bool DoWithNoteBlockAt(int a_BlockX, int a_BlockY, int a_BlockZ, cNoteBlockCallback a_Callback);
 
diff --git a/src/ChunkMap.cpp b/src/ChunkMap.cpp
index 9c721610e..f2c0cf59f 100644
--- a/src/ChunkMap.cpp
+++ b/src/ChunkMap.cpp
@@ -1629,6 +1629,24 @@ bool cChunkMap::DoWithFurnaceAt(int a_BlockX, int a_BlockY, int a_BlockZ, cFurna
 
 
 
+bool cChunkMap::DoWithHopperAt(int a_BlockX, int a_BlockY, int a_BlockZ, cHopperCallback a_Callback)
+{
+	int ChunkX, ChunkZ;
+	int BlockX = a_BlockX, BlockY = a_BlockY, BlockZ = a_BlockZ;
+	cChunkDef::AbsoluteToRelative(BlockX, BlockY, BlockZ, ChunkX, ChunkZ);
+	cCSLock Lock(m_CSChunks);
+	cChunkPtr Chunk = GetChunkNoGen(ChunkX, ChunkZ);
+	if ((Chunk == nullptr) || !Chunk->IsValid())
+	{
+		return false;
+	}
+	return Chunk->DoWithHopperAt(a_BlockX, a_BlockY, a_BlockZ, a_Callback);
+}
+
+
+
+
+
 bool cChunkMap::DoWithNoteBlockAt(int a_BlockX, int a_BlockY, int a_BlockZ, cNoteBlockCallback a_Callback)
 {
 	int ChunkX, ChunkZ;
diff --git a/src/ChunkMap.h b/src/ChunkMap.h
index 3623400c8..5c0aa7688 100644
--- a/src/ChunkMap.h
+++ b/src/ChunkMap.h
@@ -29,6 +29,7 @@ class cDispenserEntity;
 class cDropperEntity;
 class cDropSpenserEntity;
 class cFurnaceEntity;
+class cHopperEntity;
 class cNoteEntity;
 class cCommandBlockEntity;
 class cMobHeadEntity;
@@ -53,6 +54,7 @@ using cDispenserCallback    = cFunctionRef<bool(cDispenserEntity    &)>;
 using cDropperCallback      = cFunctionRef<bool(cDropperEntity      &)>;
 using cDropSpenserCallback  = cFunctionRef<bool(cDropSpenserEntity  &)>;
 using cFurnaceCallback      = cFunctionRef<bool(cFurnaceEntity      &)>;
+using cHopperCallback       = cFunctionRef<bool(cHopperEntity       &)>;
 using cNoteBlockCallback    = cFunctionRef<bool(cNoteEntity         &)>;
 using cCommandBlockCallback = cFunctionRef<bool(cCommandBlockEntity &)>;
 using cMobHeadCallback      = cFunctionRef<bool(cMobHeadEntity      &)>;
@@ -302,6 +304,10 @@ public:
 	Returns false if there's no furnace at those coords or callback returns true, returns true if found. */
 	bool DoWithFurnaceAt(int a_BlockX, int a_BlockY, int a_BlockZ, cFurnaceCallback a_Callback);  // Lua-accessible
 
+	/** Calls the callback for the hopper at the specified coords.
+	Returns false if there's no hopper at those coords or callback returns true, returns true if found. */
+	bool DoWithHopperAt(int a_BlockX, int a_BlockY, int a_BlockZ, cHopperCallback a_Callback);  // Lua-accessible
+
 	/** Calls the callback for the noteblock at the specified coords.
 	Returns false if there's no noteblock at those coords or callback returns true, returns true if found. */
 	bool DoWithNoteBlockAt(int a_BlockX, int a_BlockY, int a_BlockZ, cNoteBlockCallback a_Callback);  // Lua-accessible
diff --git a/src/Simulator/IncrementalRedstoneSimulator/CMakeLists.txt b/src/Simulator/IncrementalRedstoneSimulator/CMakeLists.txt
index fdce1bff5..fada3e662 100644
--- a/src/Simulator/IncrementalRedstoneSimulator/CMakeLists.txt
+++ b/src/Simulator/IncrementalRedstoneSimulator/CMakeLists.txt
@@ -7,6 +7,7 @@ set (HDRS
 	CommandBlockHandler.h
 	DoorHandler.h
 	DropSpenserHandler.h
+	HopperHandler.h
 	IncrementalRedstoneSimulator.h
 	RedstoneHandler.h
 	RedstoneSimulatorChunkData.h
diff --git a/src/Simulator/IncrementalRedstoneSimulator/HopperHandler.h b/src/Simulator/IncrementalRedstoneSimulator/HopperHandler.h
new file mode 100644
index 000000000..6012db1e1
--- /dev/null
+++ b/src/Simulator/IncrementalRedstoneSimulator/HopperHandler.h
@@ -0,0 +1,62 @@
+
+#pragma once
+
+#include "RedstoneHandler.h"
+#include "../../BlockEntities/HopperEntity.h"
+
+
+
+
+
+class cHopperHandler : public cRedstoneHandler
+{
+	typedef cRedstoneHandler super;
+public:
+
+	virtual unsigned char GetPowerDeliveredToPosition(cWorld & a_World, Vector3i a_Position, BLOCKTYPE a_BlockType, NIBBLETYPE a_Meta, Vector3i a_QueryPosition, BLOCKTYPE a_QueryBlockType) const override
+	{
+		UNUSED(a_World);
+		UNUSED(a_Position);
+		UNUSED(a_BlockType);
+		UNUSED(a_Meta);
+		UNUSED(a_QueryPosition);
+		UNUSED(a_QueryBlockType);
+		return 0;
+	}
+
+	virtual unsigned char GetPowerLevel(cWorld & a_World, Vector3i a_Position, BLOCKTYPE a_BlockType, NIBBLETYPE a_Meta) const override
+	{
+		UNUSED(a_World);
+		UNUSED(a_Position);
+		UNUSED(a_BlockType);
+		UNUSED(a_Meta);
+		return 0;
+	}
+
+	virtual cVector3iArray Update(cWorld & a_World, Vector3i a_Position, BLOCKTYPE a_BlockType, NIBBLETYPE a_Meta, PoweringData a_PoweringData) const override
+	{
+		// LOGD("Evaluating commander the cmdblck (%d %d %d)", a_Position.x, a_Position.y, a_Position.z);
+
+		auto Previous = static_cast<cIncrementalRedstoneSimulator *>(a_World.GetRedstoneSimulator())->GetChunkData()->ExchangeUpdateOncePowerData(a_Position, a_PoweringData);
+		if (Previous.PowerLevel != a_PoweringData.PowerLevel)
+		{
+			return {};
+		}
+
+		a_World.DoWithHopperAt(a_Position.x, a_Position.y, a_Position.z, [a_PoweringData](cHopperEntity & a_Hopper)
+			{
+				a_Hopper.SetLocked(a_PoweringData.PowerLevel != 0);
+				return false;
+			}
+		);
+		return {};
+	}
+
+	virtual cVector3iArray GetValidSourcePositions(cWorld & a_World, Vector3i a_Position, BLOCKTYPE a_BlockType, NIBBLETYPE a_Meta) const override
+	{
+		UNUSED(a_World);
+		UNUSED(a_BlockType);
+		UNUSED(a_Meta);
+		return GetAdjustedRelatives(a_Position, GetRelativeAdjacents());
+	}
+};
diff --git a/src/Simulator/IncrementalRedstoneSimulator/IncrementalRedstoneSimulator.cpp b/src/Simulator/IncrementalRedstoneSimulator/IncrementalRedstoneSimulator.cpp
index 2c56646fe..ddd682288 100644
--- a/src/Simulator/IncrementalRedstoneSimulator/IncrementalRedstoneSimulator.cpp
+++ b/src/Simulator/IncrementalRedstoneSimulator/IncrementalRedstoneSimulator.cpp
@@ -25,6 +25,7 @@
 #include "DropSpenserHandler.h"
 #include "RedstoneComparatorHandler.h"
 #include "TrappedChestHandler.h"
+#include "HopperHandler.h"
 
 
 
@@ -98,6 +99,7 @@ std::unique_ptr<cRedstoneHandler> cIncrementalRedstoneSimulator::CreateComponent
 
 		case E_BLOCK_BLOCK_OF_REDSTONE: return cpp14::make_unique<cRedstoneBlockHandler>();
 		case E_BLOCK_COMMAND_BLOCK: return cpp14::make_unique<cCommandBlockHandler>();
+		case E_BLOCK_HOPPER: return cpp14::make_unique<cHopperHandler>();
 		case E_BLOCK_NOTE_BLOCK: return cpp14::make_unique<cNoteBlockHandler>();
 		case E_BLOCK_REDSTONE_WIRE: return cpp14::make_unique<cRedstoneWireHandler>();
 		case E_BLOCK_TNT: return cpp14::make_unique<cTNTHandler>();
diff --git a/src/World.cpp b/src/World.cpp
index d8655ce11..2d0dfca9f 100644
--- a/src/World.cpp
+++ b/src/World.cpp
@@ -1531,6 +1531,15 @@ bool cWorld::DoWithFurnaceAt(int a_BlockX, int a_BlockY, int a_BlockZ, cFurnaceC
 
 
 
+bool cWorld::DoWithHopperAt(int a_BlockX, int a_BlockY, int a_BlockZ, cHopperCallback a_Callback)
+{
+	return m_ChunkMap->DoWithHopperAt(a_BlockX, a_BlockY, a_BlockZ, a_Callback);
+}
+
+
+
+
+
 bool cWorld::DoWithNoteBlockAt(int a_BlockX, int a_BlockY, int a_BlockZ, cNoteBlockCallback a_Callback)
 {
 	return m_ChunkMap->DoWithNoteBlockAt(a_BlockX, a_BlockY, a_BlockZ, a_Callback);
diff --git a/src/World.h b/src/World.h
index 7f6b1871d..e1341c9cb 100644
--- a/src/World.h
+++ b/src/World.h
@@ -45,6 +45,7 @@ class cCuboid;
 class cDispenserEntity;
 class cFlowerPotEntity;
 class cFurnaceEntity;
+class cHopperEntity;
 class cNoteEntity;
 class cMobHeadEntity;
 class cCompositeChat;
@@ -769,6 +770,9 @@ public:
 	/** Calls the callback for the furnace at the specified coords; returns false if there's no furnace at those coords or callback returns true, returns true if found */
 	bool DoWithFurnaceAt(int a_BlockX, int a_BlockY, int a_BlockZ, cFurnaceCallback a_Callback);  // Exported in ManualBindings.cpp
 
+	/** Calls the callback for the hopper at the specified coords; returns false if there's no hopper at those coords or callback returns true, returns true if found */
+	bool DoWithHopperAt(int a_BlockX, int a_BlockY, int a_BlockZ, cHopperCallback a_Callback);  // Exported in ManualBindings.cpp
+
 	/** Calls the callback for the noteblock at the specified coords; returns false if there's no noteblock at those coords or callback returns true, returns true if found */
 	bool DoWithNoteBlockAt(int a_BlockX, int a_BlockY, int a_BlockZ, cNoteBlockCallback a_Callback);  // Exported in ManualBindings.cpp