From b5410c718ece106a3b25fab4a5c37815715df275 Mon Sep 17 00:00:00 2001
From: 12xx12 <44411062+12xx12@users.noreply.github.com>
Date: Thu, 24 Sep 2020 14:53:49 +0200
Subject: [PATCH] Fix ice behaviour in world (#4927)

+ Added proper ice melting under light influence

Co-authored-by: Tiger Wang <ziwei.tiger@outlook.com>
---
 src/Blocks/BlockHandler.cpp |  3 ++-
 src/Blocks/BlockIce.h       | 51 +++++++++++++++++++++++++++++++++++--
 src/Blocks/BlockPackedIce.h | 37 +++++++++++++++++++++++++++
 src/Blocks/CMakeLists.txt   |  1 +
 4 files changed, 89 insertions(+), 3 deletions(-)
 create mode 100644 src/Blocks/BlockPackedIce.h

diff --git a/src/Blocks/BlockHandler.cpp b/src/Blocks/BlockHandler.cpp
index 274460e50..f2eb4f966 100644
--- a/src/Blocks/BlockHandler.cpp
+++ b/src/Blocks/BlockHandler.cpp
@@ -59,6 +59,7 @@
 #include "BlockNetherWart.h"
 #include "BlockObserver.h"
 #include "BlockOre.h"
+#include "BlockPackedIce.h"
 #include "BlockPiston.h"
 #include "BlockPlanks.h"
 #include "BlockPortal.h"
@@ -354,7 +355,7 @@ namespace
 	constexpr cBlockHandler                   BlockObsidianHandler              (E_BLOCK_OBSIDIAN);
 	constexpr cBlockGlazedTerracottaHandler   BlockOrangeGlazedTerracottaHandler(E_BLOCK_ORANGE_GLAZED_TERRACOTTA);
 	constexpr cBlockHandler                   BlockOrangeShulkerBoxHandler      (E_BLOCK_ORANGE_SHULKER_BOX);
-	constexpr cBlockIceHandler                BlockPackedIceHandler             (E_BLOCK_PACKED_ICE);
+	constexpr cBlockPackedIceHandler          BlockPackedIceHandler             (E_BLOCK_PACKED_ICE);
 	constexpr cBlockGlazedTerracottaHandler   BlockPinkGlazedTerracottaHandler  (E_BLOCK_PINK_GLAZED_TERRACOTTA);
 	constexpr cBlockHandler                   BlockPinkShulkerBoxHandler        (E_BLOCK_PINK_SHULKER_BOX);
 	constexpr cBlockPistonHandler             BlockPistonHandler                (E_BLOCK_PISTON);
diff --git a/src/Blocks/BlockIce.h b/src/Blocks/BlockIce.h
index e20ce6daa..10cd71b8a 100644
--- a/src/Blocks/BlockIce.h
+++ b/src/Blocks/BlockIce.h
@@ -25,9 +25,56 @@ private:
 		{
 			return cItem(m_BlockType);
 		}
-		else
+
+		return {};
+	}
+
+	virtual void OnUpdate(
+		cChunkInterface & a_ChunkInterface,
+		cWorldInterface & a_WorldInterface,
+		cBlockPluginInterface & a_PluginInterface,
+		cChunk & a_Chunk,
+		const Vector3i a_RelPos
+	) const override
+	{
+		// Disappears instantly in nether:
+		if (a_WorldInterface.GetDimension() == dimNether)
 		{
-			return {};
+			a_Chunk.SetBlock(a_RelPos, E_BLOCK_AIR, 0);
+			return;
+		}
+
+		// Artificial light on any of the surrounding block > 11 leads to melting the ice.
+		static const std::array<Vector3i, 7> Adjacents
+		{
+			{
+				{ 1, 0, 0 }, { -1, 0, 0 },
+				{ 0, 1, 0 }, { 0, -1, 0 },
+				{ 0, 0, 1 }, { 0, 0, -1 }
+			}
+		};
+
+		for (const auto Offset : Adjacents)
+		{
+			auto Position = a_RelPos + Offset;
+			const auto Chunk = a_Chunk.GetRelNeighborChunkAdjustCoords(Position);
+
+			if ((Chunk == nullptr) || !Chunk->IsValid())
+			{
+				continue;
+			}
+
+			if (!Chunk->IsLightValid())
+			{
+				Chunk->GetWorld()->QueueLightChunk(Chunk->GetPosX(), Chunk->GetPosZ());
+				continue;
+			}
+
+			if (Chunk->GetBlockLight(Position) > 11)
+			{
+				a_Chunk.SetBlock(a_RelPos, E_BLOCK_STATIONARY_WATER, 0);
+				return;
+			}
 		}
 	}
 
diff --git a/src/Blocks/BlockPackedIce.h b/src/Blocks/BlockPackedIce.h
new file mode 100644
index 000000000..e344b2a19
--- /dev/null
+++ b/src/Blocks/BlockPackedIce.h
@@ -0,0 +1,37 @@
+
+#pragma once
+
+#include "BlockHandler.h"
+
+
+
+
+
+class cBlockPackedIceHandler :
+	public cBlockHandler
+{
+	using Super = cBlockHandler;
+
+public:
+
+	using Super::Super;
+
+private:
+
+	virtual cItems ConvertToPickups(NIBBLETYPE a_BlockMeta, cBlockEntity * a_BlockEntity, const cEntity * a_Digger, const cItem * a_Tool) const override
+	{
+		// Only drop self when using silk-touch:
+		if (ToolHasSilkTouch(a_Tool))
+		{
+			return cItem(m_BlockType);
+		}
+
+		return {};
+	}
+
+	virtual ColourID GetMapBaseColourID(NIBBLETYPE a_Meta) const override
+	{
+		UNUSED(a_Meta);
+		return 5;
+	}
+} ;
diff --git a/src/Blocks/CMakeLists.txt b/src/Blocks/CMakeLists.txt
index a3d1e5cb2..167e11da0 100644
--- a/src/Blocks/CMakeLists.txt
+++ b/src/Blocks/CMakeLists.txt
@@ -61,6 +61,7 @@ target_sources(
 	BlockNetherWart.h
 	BlockObserver.h
 	BlockOre.h
+	BlockPackedIce.h
 	BlockPiston.h
 	BlockPlanks.h
 	BlockPlant.h