Refactored block-to-pickup conversion. (#4417)

src/Blocks/BlockEntity.h

@@ -3,23 +3,40 @@
 
 #include "BlockHandler.h"
 #include "ChunkInterface.h"
+#include "../Item.h"
+#include "../BlockEntities/BlockEntityWithItems.h"
 
 
 
 
-class cBlockEntityHandler : public cBlockHandler
+
+/** Wrapper for blocks that have a cBlockEntity descendant attached to them and can be "used" by the player.
+Forwards the "use" event to the block entity. */
+class cBlockEntityHandler:
+	public cBlockHandler
 {
+	using super = cBlockHandler;
+
 public:
-	cBlockEntityHandler(BLOCKTYPE a_BlockType)
-		: cBlockHandler(a_BlockType)
+
+	cBlockEntityHandler(BLOCKTYPE a_BlockType):
+		super(a_BlockType)
 	{
 	}
 
+
+
+
+
 	virtual bool OnUse(cChunkInterface & a_ChunkInterface, cWorldInterface & a_WorldInterface, cPlayer & a_Player, int a_BlockX, int a_BlockY, int a_BlockZ, eBlockFace a_BlockFace, int a_CursorX, int a_CursorY, int a_CursorZ) override
 	{
 		return a_ChunkInterface.UseBlockEntity(&a_Player, a_BlockX, a_BlockY, a_BlockZ);
 	}
 
+
+
+
+
 	virtual bool IsUseable() override
 	{
 		return true;
@@ -29,3 +46,35 @@ public:
 
 
 
+
+/** Wrapper for blocks that have a cBlockEntityWithItems descendant attached to them.
+When converting to pickups, drops self with meta reset to zero, and adds the container contents. */
+template <typename Base = cBlockEntityHandler>
+class cContainerEntityHandler:
+	public Base
+{
+public:
+
+	cContainerEntityHandler(BLOCKTYPE a_BlockType):
+		Base(a_BlockType)
+	{
+	}
+
+
+
+
+
+	virtual cItems ConvertToPickups(NIBBLETYPE a_BlockMeta, cBlockEntity * a_BlockEntity, const cEntity * a_Digger, const cItem * a_Tool) override
+	{
+		// Reset meta to 0
+		cItems res(cItem(Base::m_BlockType, 1, 0));
+
+		// Drop the contents:
+		if (a_BlockEntity != nullptr)
+		{
+			auto container = static_cast<cBlockEntityWithItems *>(a_BlockEntity);
+			res.AddItemGrid(container->GetContents());
+		}
+		return res;
+	}
+};