Refactored block placement workflow.

Multi-blocks can now use the default OnPlayerPlaced() callback in cItemHandler.

src/Items/ItemBed.h

@@ -25,10 +25,11 @@ public:
 	}
 
 
-	virtual bool OnPlayerPlace(
+	virtual bool GetBlocksToPlace(
 		cWorld & a_World, cPlayer & a_Player, const cItem & a_EquippedItem,
 		int a_BlockX, int a_BlockY, int a_BlockZ, eBlockFace a_BlockFace,
-		int a_CursorX, int a_CursorY, int a_CursorZ
+		int a_CursorX, int a_CursorY, int a_CursorZ,
+		sSetBlockVector & a_BlocksToPlace
 	) override
 	{
 		// Can only be placed on the floor:
@@ -36,12 +37,10 @@ public:
 		{
 			return false;
 		}
-		AddFaceDirection(a_BlockX, a_BlockY, a_BlockZ, a_BlockFace);
 
 		// The "foot" block:
-		sSetBlockVector blks;
 		NIBBLETYPE BlockMeta = cBlockBedHandler::RotationToMetaData(a_Player.GetYaw());
-		blks.emplace_back(a_BlockX, a_BlockY, a_BlockZ, E_BLOCK_BED, BlockMeta);
+		a_BlocksToPlace.emplace_back(a_BlockX, a_BlockY, a_BlockZ, E_BLOCK_BED, BlockMeta);
 		
 		// Check if there is empty space for the "head" block:
 		// (Vanilla only allows beds to be placed into air)
@@ -50,10 +49,8 @@ public:
 		{
 			return false;
 		}
-		blks.emplace_back(a_BlockX + Direction.x, a_BlockY, a_BlockZ + Direction.z, E_BLOCK_BED, BlockMeta | 0x08);
+		a_BlocksToPlace.emplace_back(a_BlockX + Direction.x, a_BlockY, a_BlockZ + Direction.z, E_BLOCK_BED, BlockMeta | 0x08);
-
+		return true;
-		// Place both bed blocks:
-		return a_Player.PlaceBlocks(blks);
 	}
 } ;
 

src/Items/ItemBigFlower.h

@@ -27,10 +27,11 @@ public:
 	}
 
 
-	virtual bool OnPlayerPlace(
+	virtual bool GetBlocksToPlace(
 		cWorld & a_World, cPlayer & a_Player, const cItem & a_EquippedItem,
 		int a_BlockX, int a_BlockY, int a_BlockZ, eBlockFace a_BlockFace,
-		int a_CursorX, int a_CursorY, int a_CursorZ
+		int a_CursorX, int a_CursorY, int a_CursorZ,
+		sSetBlockVector & a_BlocksToSet
 	) override
 	{
 		// Can only be placed on the floor:
@@ -38,16 +39,14 @@ public:
 		{
 			return false;
 		}
-		AddFaceDirection(a_BlockX, a_BlockY, a_BlockZ, a_BlockFace);
 
-		// Place both blocks atomically:
+		AddFaceDirection(a_BlockX, a_BlockY, a_BlockZ, a_BlockFace);
-		sSetBlockVector blks;
+		a_BlocksToSet.emplace_back(a_BlockX, a_BlockY, a_BlockZ, E_BLOCK_BIG_FLOWER, a_EquippedItem.m_ItemDamage & 0x07);
-		blks.emplace_back(a_BlockX, a_BlockY, a_BlockZ, E_BLOCK_BIG_FLOWER, a_EquippedItem.m_ItemDamage & 0x07);
 		if (a_BlockY < cChunkDef::Height - 1)
 		{
-			blks.emplace_back(a_BlockX, a_BlockY + 1, a_BlockZ, E_BLOCK_BIG_FLOWER, (a_EquippedItem.m_ItemDamage & 0x07) | 0x08);
+			a_BlocksToSet.emplace_back(a_BlockX, a_BlockY + 1, a_BlockZ, E_BLOCK_BIG_FLOWER, (a_EquippedItem.m_ItemDamage & 0x07) | 0x08);
 		}
-		return a_Player.PlaceBlocks(blks);
+		return true;
 	}
 };
 

src/Items/ItemChest.h

@@ -27,6 +27,8 @@ public:
 	}
 
 
+	/** We need an OnPlayerPlace override because we're processing neighbor chests and changing their metas,
+	the parent class cannot do that. */
 	virtual bool OnPlayerPlace(
 		cWorld & a_World, cPlayer & a_Player, const cItem & a_EquippedItem,
 		int a_BlockX, int a_BlockY, int a_BlockZ, eBlockFace a_BlockFace,
@@ -118,34 +120,32 @@ public:
 			}  // for j
 		}  // for i
 
-		// If there's no chest neighbor, place the single block chest and bail out:
+		// Get the meta of the placed chest; take existing neighbors into account:
 		BLOCKTYPE ChestBlockType = static_cast<BLOCKTYPE>(m_ItemType);
-		if (NeighborIdx < 0)
+		NIBBLETYPE Meta;
+		auto yaw = a_Player.GetYaw();
+		switch (NeighborIdx)
 		{
-			NIBBLETYPE Meta = cBlockChestHandler::PlayerYawToMetaData(a_Player.GetYaw());
+			case 0:
-			return a_Player.PlaceBlock(a_BlockX, a_BlockY, a_BlockZ, ChestBlockType, Meta);
+			case 2:
-		}
-
-		// There is a neighbor to which we need to adjust
-		double yaw = a_Player.GetYaw();
-		if ((NeighborIdx == 0) || (NeighborIdx == 2))
-		{
-			// The neighbor is in the X axis, form a X-axis-aligned dblchest:
-			NIBBLETYPE Meta = ((yaw >= -90) && (yaw < 90)) ? E_META_CHEST_FACING_ZM : E_META_CHEST_FACING_ZP;
-
-			// Place the new chest:
-			if (!a_Player.PlaceBlock(a_BlockX, a_BlockY, a_BlockZ, ChestBlockType, Meta))
 			{
-				return false;
+				// The neighbor is in the X axis, form a X-axis-aligned dblchest:
+				Meta = ((yaw >= -90) && (yaw < 90)) ? E_META_CHEST_FACING_ZM : E_META_CHEST_FACING_ZP;
+				break;
 			}
-
+			case 1:
-			// Adjust the existing chest:
+			case 3:
-			a_World.FastSetBlock(a_BlockX + CrossCoords[NeighborIdx].x, a_BlockY, a_BlockZ + CrossCoords[NeighborIdx].z, ChestBlockType, Meta);
+			{
-			return true;
+				// The neighbor is in the Z axis, form a Z-axis-aligned dblchest:
-		}
+				Meta = (yaw < 0) ? E_META_CHEST_FACING_XM : E_META_CHEST_FACING_XP;
-
+				break;
-		// The neighbor is in the Z axis, form a Z-axis-aligned dblchest:
+			}
-		NIBBLETYPE Meta = (yaw < 0) ? E_META_CHEST_FACING_XM : E_META_CHEST_FACING_XP;
+			default:
+			{
+				Meta = cBlockChestHandler::PlayerYawToMetaData(yaw);
+				break;
+			}
+		}  // switch (NeighborIdx)
 
 		// Place the new chest:
 		if (!a_Player.PlaceBlock(a_BlockX, a_BlockY, a_BlockZ, ChestBlockType, Meta))
@@ -153,8 +153,31 @@ public:
 			return false;
 		}
 
-		// Adjust the existing chest:
+		// Adjust the existing chest, if any:
-		a_World.FastSetBlock(a_BlockX + CrossCoords[NeighborIdx].x, a_BlockY, a_BlockZ + CrossCoords[NeighborIdx].z, ChestBlockType, Meta);
+		if (NeighborIdx > 0)
+		{
+			a_World.FastSetBlock(a_BlockX + CrossCoords[NeighborIdx].x, a_BlockY, a_BlockZ + CrossCoords[NeighborIdx].z, ChestBlockType, Meta);
+		}
+
+		// Play the placement sound:
+		AString PlaceSound = cBlockInfo::GetPlaceSound(ChestBlockType);
+		float Volume = 1.0f, Pitch = 0.8f;
+		if (PlaceSound == "dig.metal")
+		{
+			Pitch = 1.2f;
+			PlaceSound = "dig.stone";
+		}
+		else if (PlaceSound == "random.anvil_land")
+		{
+			Volume = 0.65f;
+		}
+		a_World.BroadcastSoundEffect(PlaceSound, a_BlockX + 0.5, a_BlockY + 0.5, a_BlockZ + 0.5, Volume, Pitch);
+
+		// Remove the "placed" item:
+		if (a_Player.IsGameModeSurvival())
+		{
+			a_Player.GetInventory().RemoveOneEquippedItem();
+		}
 		return true;
 	}
 

src/Items/ItemDoor.h

@@ -20,10 +20,11 @@ public:
 	}
 
 
-	virtual bool OnPlayerPlace(
+	virtual bool GetBlocksToPlace(
 		cWorld & a_World, cPlayer & a_Player, const cItem & a_EquippedItem,
 		int a_BlockX, int a_BlockY, int a_BlockZ, eBlockFace a_BlockFace,
-		int a_CursorX, int a_CursorY, int a_CursorZ
+		int a_CursorX, int a_CursorY, int a_CursorZ,
+		sSetBlockVector & a_BlocksToSet
 	) override
 	{
 		// Vanilla only allows door placement while clicking on the top face of the block below the door:
@@ -107,10 +108,9 @@ public:
 		}
 
 		// Set the blocks:
-		sSetBlockVector blks;
+		a_BlocksToSet.emplace_back(a_BlockX, a_BlockY, a_BlockZ, BlockType, LowerBlockMeta);
-		blks.emplace_back(a_BlockX, a_BlockY, a_BlockZ, BlockType, LowerBlockMeta);
+		a_BlocksToSet.emplace_back(a_BlockX, a_BlockY + 1, a_BlockZ, BlockType, UpperBlockMeta);
-		blks.emplace_back(a_BlockX, a_BlockY + 1, a_BlockZ, BlockType, UpperBlockMeta);
+		return true;
-		return a_Player.PlaceBlocks(blks);
 	}
 
 

src/Items/ItemHandler.cpp

@@ -367,37 +367,51 @@ bool cItemHandler::OnPlayerPlace(
 			return false;
 		}
 	}
-	
+
-	BLOCKTYPE BlockType;
+	// Get all the blocks to place:
-	NIBBLETYPE BlockMeta;
+	sSetBlockVector blocks;
-	if (!GetPlacementBlockTypeMeta(&a_World, &a_Player, a_BlockX, a_BlockY, a_BlockZ, a_BlockFace, a_CursorX, a_CursorY, a_CursorZ, BlockType, BlockMeta))
+	if (!GetBlocksToPlace(a_World, a_Player, a_EquippedItem, a_BlockX, a_BlockY, a_BlockZ, a_BlockFace, a_CursorX, a_CursorY, a_CursorZ, blocks))
 	{
 		// Handler refused the placement, send that information back to the client:
+		for (const auto & blk: blocks)
+		{
+			a_World.SendBlockTo(blk.GetX(), blk.GetY(), blk.GetZ(), &a_Player);
+		}
 		a_World.SendBlockTo(a_BlockX, a_BlockY, a_BlockZ, &a_Player);
 		a_Player.GetInventory().SendEquippedSlot();
 		return false;
 	}
 	
-	if (!a_Player.PlaceBlock(a_BlockX, a_BlockY, a_BlockZ, BlockType, BlockMeta))
+	// Try to place the blocks:
+	if (!a_Player.PlaceBlocks(blocks))
 	{
-		// The placement failed, the block has already been re-sent, re-send inventory:
+		// The placement failed, the blocks have already been re-sent, re-send inventory:
 		a_Player.GetInventory().SendEquippedSlot();
 		return false;
 	}
 
-	AString PlaceSound = cBlockInfo::GetPlaceSound(BlockType);
+	// Play the placement sound for the main block:
-	float Volume = 1.0f, Pitch = 0.8f;
+	for (const auto & blk: blocks)
-	if (PlaceSound == "dig.metal")
 	{
-		Pitch = 1.2f;
+		// Find the main block by comparing the coords:
-		PlaceSound = "dig.stone";
+		if ((blk.GetX() != a_BlockX) || (blk.GetY() != a_BlockY) || (blk.GetZ() != a_BlockZ))
-	}
+		{
-	else if (PlaceSound == "random.anvil_land")
+			continue;
-	{
+		}
-		Volume = 0.65f;
+		AString PlaceSound = cBlockInfo::GetPlaceSound(blk.m_BlockType);
-	}
+		float Volume = 1.0f, Pitch = 0.8f;
-
+		if (PlaceSound == "dig.metal")
-	a_World.BroadcastSoundEffect(PlaceSound, a_BlockX + 0.5, a_BlockY + 0.5, a_BlockZ + 0.5, Volume, Pitch);
+		{
+			Pitch = 1.2f;
+			PlaceSound = "dig.stone";
+		}
+		else if (PlaceSound == "random.anvil_land")
+		{
+			Volume = 0.65f;
+		}
+		a_World.BroadcastSoundEffect(PlaceSound, a_BlockX + 0.5, a_BlockY + 0.5, a_BlockZ + 0.5, Volume, Pitch);
+		break;
+	}  // for blk - blocks[]
 
 	// Remove the "placed" item:
 	if (a_Player.IsGameModeSurvival())
@@ -411,6 +425,27 @@ bool cItemHandler::OnPlayerPlace(
 
 
 
+bool cItemHandler::GetBlocksToPlace(
+	cWorld & a_World, cPlayer & a_Player, const cItem & a_EquippedItem,
+	int a_BlockX, int a_BlockY, int a_BlockZ, eBlockFace a_BlockFace,
+	int a_CursorX, int a_CursorY, int a_CursorZ,
+	sSetBlockVector & a_BlocksToSet
+)
+{
+	BLOCKTYPE BlockType;
+	NIBBLETYPE BlockMeta;
+	if (!GetPlacementBlockTypeMeta(&a_World, &a_Player, a_BlockX, a_BlockY, a_BlockZ, a_BlockFace, a_CursorX, a_CursorY, a_CursorZ, BlockType, BlockMeta))
+	{
+		return false;
+	}
+	a_BlocksToSet.emplace_back(a_BlockX, a_BlockY, a_BlockZ, BlockType, BlockMeta);
+	return true;
+}
+
+
+
+
+
 bool cItemHandler::OnItemUse(
 	cWorld * a_World, cPlayer * a_Player, cBlockPluginInterface & a_PluginInterface, const cItem & a_Item,
 	int a_BlockX, int a_BlockY, int a_BlockZ, eBlockFace a_BlockFace

src/Items/ItemHandler.h

@@ -35,8 +35,9 @@ public:
 
 
 	/** Called when the player tries to place the item (right mouse button, IsPlaceable() == true).
-	The default handler uses GetPlacementBlockTypeMeta and places the returned block.
+	The block coords are for the block that has been clicked.
-	Override this function for advanced behavior such as placing multiple blocks.
+	The default handler uses GetBlocksToPlace() and places the returned blocks.
+	Override if the item needs advanced processing, such as spawning a mob based on the blocks being placed.
 	If the block placement is refused inside this call, it will automatically revert the client-side changes.
 	Returns true if the placement succeeded, false if the placement was aborted for any reason. */
 	virtual bool OnPlayerPlace(
@@ -46,7 +47,20 @@ public:
 	);
 	
 
-	/** Called when the player right-clicks with this item and IsPlaceable() == true, and OnPlace() is not overridden.
+	/** Called from OnPlayerPlace() to determine the blocks that the current placement operation should set.
+	The block coords are where the new (main) block should be placed.
+	The default handler uses GetPlacementBlockTypeMeta() and provides that as the single block at the specified coords.
+	Returns true if the placement succeeded, false if the placement was aborted for any reason.
+	If aborted, the server then sends all original blocks in the coords provided in a_BlocksToSet to the client. */
+	virtual bool GetBlocksToPlace(
+		cWorld & a_World, cPlayer & a_Player, const cItem & a_EquippedItem,
+		int a_BlockX, int a_BlockY, int a_BlockZ, eBlockFace a_BlockFace,
+		int a_CursorX, int a_CursorY, int a_CursorZ,
+		sSetBlockVector & a_BlocksToSet
+	);
+
+
+	/** Called when the player right-clicks with this item and IsPlaceable() == true, and OnPlayerPlace() is not overridden.
 	This function should provide the block type and meta for the placed block, or refuse the placement.
 	Returns true to allow placement, false to refuse. */
 	virtual bool GetPlacementBlockTypeMeta(

src/Items/ItemMobHead.h

@@ -12,9 +12,11 @@
 class cItemMobHeadHandler :
 	public cItemHandler
 {
+	typedef cItemHandler super;
+
 public:
 	cItemMobHeadHandler(int a_ItemType) :
-		cItemHandler(a_ItemType)
+		super(a_ItemType)
 	{
 	}
 
@@ -30,34 +32,36 @@ public:
 		{
 			return true;
 		}
-		AddFaceDirection(a_BlockX, a_BlockY, a_BlockZ, a_BlockFace);
+		auto placedX = a_BlockX, placedY = a_BlockY, placedZ = a_BlockZ;
+		AddFaceDirection(placedY, placedY, placedZ, a_BlockFace);
 
 		// If the placed head is a wither, try to spawn the wither first:
 		if (a_EquippedItem.m_ItemDamage == E_META_HEAD_WITHER)
 		{
-			if (TrySpawnWitherAround(a_World, a_Player, a_BlockX, a_BlockY, a_BlockZ))
+			if (TrySpawnWitherAround(a_World, a_Player, placedX, placedY, placedZ))
 			{
 				return true;
 			}
 			// Wither not created, proceed with regular head placement
 		}
 
-		return PlaceRegularHead(a_World, a_Player, a_EquippedItem, a_BlockX, a_BlockY, a_BlockZ, a_BlockFace);
+		cItem itemCopy(a_EquippedItem);  // Make a copy in case this is the player's last head item and OnPlayerPlace removes it
+		if (!super::OnPlayerPlace(a_World, a_Player, a_EquippedItem, a_BlockX, a_BlockY, a_BlockZ, a_BlockFace, a_CursorX, a_CursorY, a_CursorZ))
+		{
+			return false;
+		}
+		RegularHeadPlaced(a_World, a_Player, itemCopy, placedX, placedY, placedZ, a_BlockFace);
+		return true;
 	}
 
 
-	/** Places a regular head block with no mob spawning checking. */
+	/** Called after placing a regular head block with no mob spawning.
-	bool PlaceRegularHead(
+	Adjusts the mob head entity based on the equipped item's data. */
+	void RegularHeadPlaced(
 		cWorld & a_World, cPlayer & a_Player, const cItem & a_EquippedItem,
 		int a_BlockX, int a_BlockY, int a_BlockZ, eBlockFace a_BlockFace
 	)
 	{
-		// Place the block:
-		if (!a_Player.PlaceBlock(a_BlockX, a_BlockY, a_BlockZ, E_BLOCK_HEAD, BlockFaceToBlockMeta(a_BlockFace)))
-		{
-			return false;
-		}
-
 		// Use a callback to set the properties of the mob head block entity:
 		class cCallback : public cBlockEntityCallback
 		{
@@ -71,7 +75,7 @@ public:
 				{
 					return false;
 				}
-				cMobHeadEntity * MobHeadEntity = static_cast<cMobHeadEntity *>(a_BlockEntity);
+				auto MobHeadEntity = static_cast<cMobHeadEntity *>(a_BlockEntity);
 
 				int Rotation = 0;
 				if (m_BlockMeta == 1)
@@ -94,7 +98,6 @@ public:
 		};
 		cCallback Callback(a_Player, static_cast<eMobHeadType>(a_EquippedItem.m_ItemDamage), static_cast<NIBBLETYPE>(a_BlockFace));
 		a_World.DoWithBlockEntityAt(a_BlockX, a_BlockY, a_BlockZ, Callback);
-		return true;
 	}
 
 
@@ -340,7 +343,7 @@ public:
 	) override
 	{
 		a_BlockType = E_BLOCK_HEAD;
-		a_BlockMeta = (NIBBLETYPE)(a_Player->GetEquippedItem().m_ItemDamage & 0x0f);
+		a_BlockMeta = BlockFaceToBlockMeta(a_BlockFace);
 		return true;
 	}
 } ;