From f1f81371affec4e1f5f8fe69c84e8cc50dc1e3f6 Mon Sep 17 00:00:00 2001
From: MihailRis <mexaruc@gmail.com>
Date: Sun, 19 Jan 2025 23:36:37 +0300
Subject: [PATCH] add world.save_chunk_data(...)

---
 src/logic/scripting/lua/libs/libworld.cpp | 22 ++++++++++++
 src/voxels/compressed_chunks.cpp          | 44 +++++++++++++++++++----
 src/voxels/compressed_chunks.hpp          |  2 ++
 3 files changed, 62 insertions(+), 6 deletions(-)

diff --git a/src/logic/scripting/lua/libs/libworld.cpp b/src/logic/scripting/lua/libs/libworld.cpp
index bbba422df..5db150b0d 100644
--- a/src/logic/scripting/lua/libs/libworld.cpp
+++ b/src/logic/scripting/lua/libs/libworld.cpp
@@ -6,6 +6,7 @@
 #include "assets/AssetsLoader.hpp"
 #include "coders/json.hpp"
 #include "engine/Engine.hpp"
+#include "files/WorldFiles.hpp"
 #include "files/engine_paths.hpp"
 #include "files/files.hpp"
 #include "lighting/Lighting.hpp"
@@ -158,9 +159,14 @@ static void integrate_chunk_client(Chunk& chunk) {
 }
 
 static int l_set_chunk_data(lua::State* L) {
+    if (level == nullptr) {
+        throw std::runtime_error("no open world");
+    }
+
     int x = static_cast<int>(lua::tointeger(L, 1));
     int z = static_cast<int>(lua::tointeger(L, 2));
     auto buffer = lua::require_bytearray(L, 3);
+
     auto chunk = level->chunks->getChunk(x, z);
     if (chunk == nullptr) {
         return lua::pushboolean(L, false);
@@ -175,6 +181,21 @@ static int l_set_chunk_data(lua::State* L) {
     return lua::pushboolean(L, true);
 }
 
+static int l_save_chunk_data(lua::State* L) {
+    if (level == nullptr) {
+        throw std::runtime_error("no open world");
+    }
+
+    int x = static_cast<int>(lua::tointeger(L, 1));
+    int z = static_cast<int>(lua::tointeger(L, 2));
+    auto buffer = lua::require_bytearray(L, 3);
+
+    compressed_chunks::save(
+        x, z, std::move(buffer), level->getWorld()->wfile->getRegions()
+    );
+    return 0;
+}
+
 static int l_count_chunks(lua::State* L) {
     if (level == nullptr) {
         return 0;
@@ -197,6 +218,7 @@ const luaL_Reg worldlib[] = {
     {"exists", lua::wrap<l_exists>},
     {"get_chunk_data", lua::wrap<l_get_chunk_data>},
     {"set_chunk_data", lua::wrap<l_set_chunk_data>},
+    {"save_chunk_data", lua::wrap<l_save_chunk_data>},
     {"count_chunks", lua::wrap<l_count_chunks>},
     {NULL, NULL}
 };
diff --git a/src/voxels/compressed_chunks.cpp b/src/voxels/compressed_chunks.cpp
index 0e6772af8..64000a79a 100644
--- a/src/voxels/compressed_chunks.cpp
+++ b/src/voxels/compressed_chunks.cpp
@@ -3,6 +3,7 @@
 #include "coders/rle.hpp"
 #include "coders/gzip.hpp"
 #include "coders/byte_utils.hpp"
+#include "files/WorldFiles.hpp"
 #include "voxels/Chunk.hpp"
 
 inline constexpr int HAS_VOXELS = 0x1;
@@ -34,6 +35,15 @@ std::vector<ubyte> compressed_chunks::encode(const Chunk& chunk) {
     return builder.build();
 }
 
+static void read_voxel_data(ByteReader& reader, util::Buffer<ubyte>& dst) {
+    size_t gzipCompressedSize = reader.getInt32();
+        
+    auto rleData = gzip::decompress(reader.pointer(), gzipCompressedSize);
+    reader.skip(gzipCompressedSize);
+
+    extrle::decode16(rleData.data(), rleData.size(), dst.data());
+}
+
 void compressed_chunks::decode(Chunk& chunk, const ubyte* src, size_t size) {
     ByteReader reader(src, size);
 
@@ -41,14 +51,9 @@ void compressed_chunks::decode(Chunk& chunk, const ubyte* src, size_t size) {
     reader.skip(1); // reserved byte
 
     if (flags & HAS_VOXELS) {
-        size_t gzipCompressedSize = reader.getInt32();
-        
-        auto rleData = gzip::decompress(reader.pointer(), gzipCompressedSize);
-        reader.skip(gzipCompressedSize);
-
         /// world.get_chunk_data is only available in the main Lua state
         static util::Buffer<ubyte> voxelData (CHUNK_DATA_LEN);
-        extrle::decode16(rleData.data(), rleData.size(), voxelData.data());
+        read_voxel_data(reader, voxelData);
         chunk.decode(voxelData.data());
         chunk.updateHeights();
     }
@@ -59,3 +64,30 @@ void compressed_chunks::decode(Chunk& chunk, const ubyte* src, size_t size) {
     }
     chunk.setModifiedAndUnsaved();
 }
+
+void compressed_chunks::save(
+    int x, int z, std::vector<ubyte> bytes, WorldRegions& regions
+) {
+    ByteReader reader(bytes.data(), bytes.size());
+
+    ubyte flags = reader.get();
+    reader.skip(1); // reserved byte
+    if (flags & HAS_VOXELS) {
+        util::Buffer<ubyte> voxelData (CHUNK_DATA_LEN);
+        read_voxel_data(reader, voxelData);
+        regions.put(
+            x, z, REGION_LAYER_VOXELS, voxelData.release(), CHUNK_DATA_LEN
+        );
+    }
+    if (flags & HAS_METADATA) {
+        size_t metadataSize = reader.getInt32();
+        regions.put(
+            x,
+            z,
+            REGION_LAYER_BLOCKS_DATA,
+            util::Buffer<ubyte>(reader.pointer(), metadataSize).release(),
+            metadataSize
+        );
+        reader.skip(metadataSize);
+    }
+}
diff --git a/src/voxels/compressed_chunks.hpp b/src/voxels/compressed_chunks.hpp
index dc0bc5b6a..2181669cd 100644
--- a/src/voxels/compressed_chunks.hpp
+++ b/src/voxels/compressed_chunks.hpp
@@ -5,8 +5,10 @@
 #include <vector>
 
 class Chunk;
+class WorldRegions;
 
 namespace compressed_chunks {
     std::vector<ubyte> encode(const Chunk& chunk);
     void decode(Chunk& chunk, const ubyte* src, size_t size);
+    void save(int x, int z, std::vector<ubyte> bytes, WorldRegions& regions);
 }