From c18eddb63c832b8691983a41e9ad9b1b07f8b741 Mon Sep 17 00:00:00 2001
From: MihailRis <mexaruc@gmail.com>
Date: Thu, 5 Sep 2024 11:29:07 +0300
Subject: [PATCH] add Chunk.encodeV2, decodeV2

---
 src/files/WorldConverter.cpp |  2 +-
 src/files/compatibility.cpp  |  2 +-
 src/files/compatibility.hpp  |  2 +-
 src/voxels/Chunk.cpp         | 33 +++++++++++++++++++++++++++++++++
 src/voxels/Chunk.hpp         |  9 +++++++++
 5 files changed, 45 insertions(+), 3 deletions(-)

diff --git a/src/files/WorldConverter.cpp b/src/files/WorldConverter.cpp
index 4748172d..5d24889d 100644
--- a/src/files/WorldConverter.cpp
+++ b/src/files/WorldConverter.cpp
@@ -161,7 +161,7 @@ void WorldConverter::upgradeRegion(
 ) const {
     auto path = wfile->getRegions().getRegionFilePath(layer, x, z);
     auto bytes = files::read_bytes_buffer(path);
-    auto buffer = compatibility::convertRegion2to3(bytes, layer);
+    auto buffer = compatibility::convert_region_2to3(bytes, layer);
     files::write_bytes(path, buffer.data(), buffer.size());
 }
 
diff --git a/src/files/compatibility.cpp b/src/files/compatibility.cpp
index 0d9d6c08..161527b1 100644
--- a/src/files/compatibility.cpp
+++ b/src/files/compatibility.cpp
@@ -39,7 +39,7 @@ static util::Buffer<ubyte> convert_voxels_1to2(const ubyte* buffer, uint32_t siz
     return util::Buffer<ubyte>(std::move(compressed), outLen);
 }
 
-util::Buffer<ubyte> compatibility::convertRegion2to3(
+util::Buffer<ubyte> compatibility::convert_region_2to3(
     const util::Buffer<ubyte>& src, RegionLayerIndex layer
 ) {
     const size_t REGION_CHUNKS = 1024;
diff --git a/src/files/compatibility.hpp b/src/files/compatibility.hpp
index eef5b218..cf78b5bc 100644
--- a/src/files/compatibility.hpp
+++ b/src/files/compatibility.hpp
@@ -9,6 +9,6 @@ namespace compatibility {
     /// @see /doc/specs/region_file_spec.md
     /// @param src region file source content
     /// @return new region file content
-    util::Buffer<ubyte> convertRegion2to3(
+    util::Buffer<ubyte> convert_region_2to3(
         const util::Buffer<ubyte>& src, RegionLayerIndex layer);
 }
diff --git a/src/voxels/Chunk.cpp b/src/voxels/Chunk.cpp
index c77532da..5dfb9fe3 100644
--- a/src/voxels/Chunk.cpp
+++ b/src/voxels/Chunk.cpp
@@ -5,6 +5,7 @@
 #include "content/ContentReport.hpp"
 #include "items/Inventory.hpp"
 #include "lighting/Lightmap.hpp"
+#include "util/data_io.hpp"
 #include "voxel.hpp"
 
 Chunk::Chunk(int xpos, int zpos) : x(xpos), z(zpos) {
@@ -103,6 +104,27 @@ std::unique_ptr<ubyte[]> Chunk::encode() const {
     return buffer;
 }
 
+/**
+  Current chunk format:
+    - byte-order: little-endian
+
+    ```cpp
+    uint16_t voxel_id[CHUNK_VOL];
+    uint16_t voxel_states[CHUNK_VOL];
+    ```
+
+    Total size: (CHUNK_VOL * 4) bytes
+*/
+std::unique_ptr<ubyte[]> Chunk::encodeV2() const {
+    auto buffer = std::make_unique<ubyte[]>(CHUNK_DATA_LEN);
+    auto dst = reinterpret_cast<uint16_t*>(buffer.get());
+    for (uint i = 0; i < CHUNK_VOL; i++) {
+        dst[i] = dataio::h2le(voxels[i].id);
+        dst[CHUNK_VOL + i] = dataio::h2le(blockstate2int(voxels[i].state));
+    }
+    return buffer;
+}
+
 bool Chunk::decode(const ubyte* data) {
     for (uint i = 0; i < CHUNK_VOL; i++) {
         voxel& vox = voxels[i];
@@ -123,6 +145,17 @@ bool Chunk::decode(const ubyte* data) {
     return true;
 }
 
+bool Chunk::decodeV2(const ubyte* data) {
+    auto src = reinterpret_cast<const uint16_t*>(data);
+    for (uint i = 0; i < CHUNK_VOL; i++) {
+        voxel& vox = voxels[i];
+
+        vox.id = dataio::le2h(src[i]);
+        vox.state = int2blockstate(dataio::le2h(src[CHUNK_VOL + i]));
+    }
+    return true;
+}
+
 void Chunk::convert(ubyte* data, const ContentReport* report) {
     for (uint i = 0; i < CHUNK_VOL; i++) {
         // see encode method to understand what the hell is going on here
diff --git a/src/voxels/Chunk.hpp b/src/voxels/Chunk.hpp
index d9a25186..bd8bf965 100644
--- a/src/voxels/Chunk.hpp
+++ b/src/voxels/Chunk.hpp
@@ -66,10 +66,19 @@ public:
         flags.unsaved = true;
     }
 
+    /// @brief Encode chunk to bytes array of size CHUNK_DATA_LEN
+    /// @see /doc/specs/outdated/region_voxels_chunk_spec_v1.md
     std::unique_ptr<ubyte[]> encode() const;
 
+    /// @brief Encode chunk to bytes array of size CHUNK_DATA_LEN
+    /// @see /doc/specs/region_voxels_chunk_spec.md
+    std::unique_ptr<ubyte[]> encodeV2() const;
+
     /// @return true if all is fine
     bool decode(const ubyte* data);
 
+    /// @return true if all is fine
+    bool decodeV2(const ubyte* data);
+
     static void convert(ubyte* data, const ContentReport* report);
 };