feat(client-chunk): add greedy meshing, receive_chunk, and biome field

include/Cubed/gameplay/biome.hpp

@@ -1,6 +1,9 @@
 #pragma once
+#include "Cubed/tools/cubed_assert.hpp"
+
 #include <array>
 #include <string>
+#include <utility>
 #include <vector>
 
 namespace Cubed {
@@ -77,4 +80,32 @@ DesertParams& desert_params();
 MountainParams& mountain_params();
 RiverParams& river_params();
 
+inline BiomeType get_biome(int id) {
+    using enum BiomeType;
+    auto to = std::to_underlying<BiomeType>;
+    if (id == to(PLAIN)) {
+        return PLAIN;
+    }
+    if (id == to(FOREST)) {
+        return FOREST;
+    }
+    if (id == to(DESERT)) {
+        return DESERT;
+    }
+    if (id == to(MOUNTAIN)) {
+        return MOUNTAIN;
+    }
+    if (id == to(RIVER)) {
+        return RIVER;
+    }
+    if (id == to(SNOWY_PLAIN)) {
+        return SNOWY_PLAIN;
+    }
+    if (id == to(OCEAN)) {
+        return OCEAN;
+    }
+    ASSERT_MSG(false, "Unknown Biome Id");
+    throw std::invalid_argument("Unknown Biome Id");
+}
+
 } // namespace Cubed

include/Cubed/gameplay/client_chunk.hpp

@@ -4,6 +4,7 @@
 #include "Cubed/gameplay/block.hpp"
 #include "Cubed/gameplay/chunk_pos.hpp"
 #include "Cubed/gameplay/vertex_data.hpp"
+#include "world/chunk_data.pb.h"
 
 #include <atomic>
 #include <glad/glad.h>
@@ -34,9 +35,13 @@ public:
     ClientChunk(ClientChunk&&) noexcept;
     ClientChunk& operator=(ClientChunk&&) noexcept;
 
+    static int index(int x, int y, int z);
+    static int index(const glm::vec3& pos);
+
     BiomeType get_biome() const;
     ChunkPos get_chunk_pos() const;
     const std::vector<BlockType>& get_chunk_blocks() const;
+    void receive_chunk(const ChunkDataRsp& data);
     void gen_vertex_data(const OptionalBlockVectorArray& neighbor_block);
     void upload_to_gpu();
 
@@ -85,6 +90,7 @@ private:
     static constexpr int SIZE_X = CHUNK_SIZE;
     static constexpr int SIZE_Y = WORLD_SIZE_Y;
     static constexpr int SIZE_Z = CHUNK_SIZE;
+    static constexpr int BLOCK_SIZE = SIZE_X * SIZE_Y * SIZE_Z;
     static constexpr int VERTEX_DATA_SUM = 5;
     std::atomic<bool> m_dirty{false};
     std::atomic<bool> m_need_upload{true};

src/gameplay/client_chunk.cpp

@@ -0,0 +1,521 @@
+#include "Cubed/gameplay/client_chunk.hpp"
+
+#include "Cubed/tools/cubed_assert.hpp"
+
+namespace Cubed {
+using OptionalBlockVectorArray =
+    std::array<std::optional<std::vector<BlockType>>, 4>;
+namespace {
+// ────────────────────────────────────────────────────────────────────────────
+// Face direction mapping
+//   Original DIR[6]: {+Z,+X,-Z,-X,+Y,-Y}  => face index 0-5
+//   Axis × direction => face:
+//     axis=2(Z) dir=+1 => face 0   (+Z)
+//     axis=0(X) dir=+1 => face 1   (+X)
+//     axis=2(Z) dir=-1 => face 2   (-Z)
+//     axis=0(X) dir=-1 => face 3   (-X)
+//     axis=1(Y) dir=+1 => face 4   (+Y)
+//     axis=1(Y) dir=-1 => face 5   (-Y)
+// ────────────────────────────────────────────────────────────────────────────
+
+inline int axis_dir_to_face(int axis, int dir) {
+    // axis: 0=X 1=Y 2=Z
+    // dir:  +1 or -1
+    static const int TABLE[3][2] = {
+        {3, 1}, // X: dir=-1->face3(-X), dir=+1->face1(+X)
+        {5, 4}, // Y: dir=-1->face5(-Y), dir=+1->face4(+Y)
+        {2, 0}, // Z: dir=-1->face2(-Z), dir=+1->face0(+Z)
+    };
+    return TABLE[axis][dir > 0 ? 1 : 0];
+}
+
+inline BlockType
+get_block_safe(int lx, int ly, int lz, ChunkPos& chunk_pos,
+               const std::vector<BlockType>& blocks,
+               const OptionalBlockVectorArray& neighbor_block) {
+    if (lx >= 0 && lx < CHUNK_SIZE && ly >= 0 && ly < WORLD_SIZE_Y && lz >= 0 &&
+        lz < CHUNK_SIZE) {
+        return blocks[ClientChunk::index(lx, ly, lz)];
+    }
+
+    // Out of bounds: check neighbors
+    int world_x = lx + chunk_pos.x * CHUNK_SIZE;
+    int world_z = lz + chunk_pos.z * CHUNK_SIZE;
+
+    auto [nb_cx, nb_cz] = get_chunk_pos(world_x, world_z);
+
+    const std::optional<std::vector<BlockType>>* nb = nullptr;
+    if (nb_cx == chunk_pos.x + 1)
+        nb = &neighbor_block[0];
+    else if (nb_cx == chunk_pos.x - 1)
+        nb = &neighbor_block[1];
+    else if (nb_cz == chunk_pos.z + 1)
+        nb = &neighbor_block[2];
+    else if (nb_cz == chunk_pos.z - 1)
+        nb = &neighbor_block[3];
+
+    if (!nb || !nb->has_value())
+        return 0; // Neighbor does not exist, treat as opaque
+
+    int nbx = world_x - nb_cx * CHUNK_SIZE;
+    int nby = ly;
+    int nbz = world_z - nb_cz * CHUNK_SIZE;
+
+    if (nbx < 0 || nby < 0 || nbz < 0 || nbx >= CHUNK_SIZE ||
+        nby >= WORLD_SIZE_Y || nbz >= CHUNK_SIZE)
+        return 0;
+
+    int idx = ClientChunk::index(nbx, nby, nbz);
+    if (static_cast<size_t>(idx) >= (*nb)->size()) {
+        return 0;
+    }
+
+    return (**nb)[idx];
+}
+// Determine whether the face from cur_id looking towards neighbor_id should be
+// culled (does not need to be rendered)
+inline bool is_face_culled(BlockType cur_id, BlockType neighbor_id) {
+    if (!BlockManager::is_transparent(neighbor_id))
+        return true; // Neighbor is opaque, blocking
+    // Neighbor transparency: same block type culls each other (e.g., water
+    // adjacent to water does not render internal faces)
+    if (neighbor_id == cur_id)
+        return true;
+    return false;
+}
+
+inline int choose_buf(BlockType id) {
+    if (!BlockManager::is_transparent(id))
+        return 0;
+    if (BlockManager::is_discard(id))
+        return 2;
+    if (BlockManager::is_blend(id)) {
+        return (id == 7) ? 4 : 3; // water=4, other blend=3
+    }
+    return 3; // fallback
+}
+
+} // namespace
+ClientChunk::ClientChunk(ClientWorld& world) : m_world(world) {}
+ClientChunk::~ClientChunk() {}
+
+ClientChunk::ClientChunk(ClientChunk&& other) noexcept
+    : m_dirty(other.is_dirty()), m_need_upload(other.m_need_upload.load()),
+      m_is_on_gen_vertex_data(other.m_is_on_gen_vertex_data.load()),
+      m_biome(other.m_biome.load()), m_chunk_pos(std::move(other.m_chunk_pos)),
+      m_world(other.m_world), m_blocks(std::move(other.m_blocks)),
+      m_vertex_data(std::move(other.m_vertex_data)), m_seed(other.m_seed) {}
+
+ClientChunk& ClientChunk::operator=(ClientChunk&& other) noexcept {
+    // Logger::info("other Chunk pos {} {} in Chunk& Chunk::operator=(Chunk&&
+    // other) this {}", other.m_chunk_pos.x, other.m_chunk_pos.z,
+    // static_cast<const void*>(&other));
+
+    m_chunk_pos = std::move(other.m_chunk_pos);
+    m_blocks = std::move(other.m_blocks);
+    m_dirty = other.is_dirty();
+    m_vertex_data = std::move(other.m_vertex_data);
+    m_biome = other.m_biome.load();
+    m_is_on_gen_vertex_data = other.m_is_on_gen_vertex_data.load();
+    m_need_upload = other.m_need_upload.load();
+    m_seed = other.m_seed;
+    return *this;
+}
+
+int ClientChunk::index(int x, int y, int z) {
+    ASSERT(!(x < 0 || y < 0 || z < 0 || x >= CHUNK_SIZE || y >= WORLD_SIZE_Y ||
+             z >= CHUNK_SIZE));
+    if ((x * WORLD_SIZE_Y + y) * CHUNK_SIZE + z < 0 ||
+        (x * WORLD_SIZE_Y + y) * CHUNK_SIZE + z >=
+            CHUNK_SIZE * CHUNK_SIZE * WORLD_SIZE_Y) {
+        Logger::error("block pos x {} y {} z {} range error", x, y, z);
+        ASSERT(0);
+    }
+    return (x * WORLD_SIZE_Y + y) * CHUNK_SIZE + z;
+}
+
+int ClientChunk::index(const glm::vec3& pos) {
+    return ClientChunk::index(pos.x, pos.y, pos.z);
+}
+
+BiomeType ClientChunk::get_biome() const { return m_biome.load(); }
+
+ChunkPos ClientChunk::get_chunk_pos() const { return m_chunk_pos; }
+
+const std::vector<BlockType>& ClientChunk::get_chunk_blocks() const {
+    return m_blocks;
+}
+
+void ClientChunk::gen_vertex_data(
+    const OptionalBlockVectorArray& neighbor_block) {
+    if (m_is_on_gen_vertex_data.exchange(true)) {
+        return;
+    }
+    std::lock_guard lk(m_vertexs_data_mutex);
+
+    for (auto& data : m_vertex_data) {
+        data.m_vertices.clear();
+    }
+
+    gen_vertices(neighbor_block);
+    for (auto& data : m_vertex_data) {
+        data.update_sum();
+    }
+    m_need_upload = true;
+    m_is_on_gen_vertex_data = false;
+}
+
+GLuint ClientChunk::get_normal_vao() const { return m_vertex_data[0].m_vao; }
+
+size_t ClientChunk::get_normal_vertices_sum() const {
+    if (m_vertex_data[0].m_sum == 0) {
+        Logger::warn("m_normal_vertices_sum is 0");
+    }
+    return m_vertex_data[0].m_sum.load();
+}
+
+GLuint ClientChunk::get_cross_vao() const { return m_vertex_data[1].m_vao; }
+size_t ClientChunk::get_cross_vertices_sum() const {
+    return m_vertex_data[1].m_sum.load();
+}
+
+GLuint ClientChunk::get_normal_discard_vao() const {
+    return m_vertex_data[2].m_vao;
+}
+size_t ClientChunk::get_normal_discard_vertices_sum() const {
+    return m_vertex_data[2].m_sum.load();
+}
+
+GLuint ClientChunk::get_normal_blend_vao() const {
+    return m_vertex_data[3].m_vao;
+}
+size_t ClientChunk::get_normal_blend_vertices_sum() const {
+    return m_vertex_data[3].m_sum.load();
+}
+
+GLuint ClientChunk::get_water_vao() const { return m_vertex_data[4].m_vao; }
+size_t ClientChunk::get_water_vertices_sum() const {
+    return m_vertex_data[4].m_sum.load();
+}
+
+void ClientChunk::upload_to_gpu() {
+
+    ASSERT(is_need_upload());
+
+    std::lock_guard lk(m_vertexs_data_mutex);
+
+    for (auto& data : m_vertex_data) {
+        data.upload();
+    }
+
+    // after fininshed it, can use
+    clear_dirty();
+    m_need_upload = false;
+}
+
+bool ClientChunk::is_dirty() const { return m_dirty.load(); }
+
+void ClientChunk::mark_dirty() { m_dirty = true; }
+
+void ClientChunk::clear_dirty() { m_dirty = false; }
+
+bool ClientChunk::is_need_upload() const { return m_need_upload.load(); }
+
+void ClientChunk::need_upload() { m_need_upload = true; }
+
+void ClientChunk::set_chunk_block(int index, unsigned id) {
+    m_blocks[index] = id;
+    mark_dirty();
+}
+
+ChunkPos ClientChunk::chunk_pos() const { return m_chunk_pos; }
+
+BiomeType ClientChunk::biome() const { return m_biome; }
+
+void ClientChunk::biome(BiomeType b) { m_biome = b; }
+
+std::vector<BlockType>& ClientChunk::blocks() { return m_blocks; }
+ClientWorld& ClientChunk::world() { return m_world; }
+unsigned ClientChunk::seed() const {
+    if (m_seed == 0) {
+        Logger::warn("Seed Not Generator");
+    }
+    return m_seed;
+}
+
+void ClientChunk::gen_vertices(const OptionalBlockVectorArray& neighbor_block) {
+
+    // SIZE_X=SIZE_Z=CHUNK_SIZE=16, SIZE_Y=WORLD_SIZE_Y=256
+    // Axis order: axis 0=X, 1=Y, 2=Z
+    // Two slice dimensions of each axis
+    const int DIMS[3] = {CHUNK_SIZE, WORLD_SIZE_Y, CHUNK_SIZE};
+
+    // Maximum mask size: max(16*256, 16*16) = 4096
+    static thread_local FaceKey mask[CHUNK_SIZE * WORLD_SIZE_Y];
+    static thread_local bool visited[CHUNK_SIZE * WORLD_SIZE_Y];
+
+    for (int axis = 0; axis < 3; axis++) {
+        int u_axis = (axis + 1) % 3; // horizontal
+        int v_axis = (axis + 2) % 3; // vertical
+
+        int u = DIMS[u_axis];
+        int v = DIMS[v_axis];
+        int d = DIMS[axis]; // Depth along the normal axis
+
+        for (int face_dir : {1, -1}) {
+            int face_idx = axis_dir_to_face(axis, face_dir);
+
+            for (int layer = 0; layer < d; layer++) {
+
+                // ── 1. Build mask ──────────────────────────────────────────
+                for (int vi = 0; vi < v; vi++) {
+                    for (int ui = 0; ui < u; ui++) {
+                        // Current cell local coordinates
+                        int lpos[3];
+                        lpos[axis] = layer;
+                        lpos[u_axis] = ui;
+                        lpos[v_axis] = vi;
+
+                        // Neighbor (offset one cell along the normal direction)
+                        int npos[3];
+                        npos[axis] = layer + face_dir;
+                        npos[u_axis] = ui;
+                        npos[v_axis] = vi;
+
+                        BlockType cur_id = get_block_safe(
+                            lpos[0], lpos[1], lpos[2], m_chunk_pos, m_blocks,
+                            neighbor_block);
+
+                        // Air / cross plane are not involved in greedy meshing
+                        if (cur_id == 0 ||
+                            BlockManager::is_cross_plane(cur_id)) {
+                            mask[vi * u + ui] = {};
+                            continue;
+                        }
+
+                        BlockType nb_id = get_block_safe(
+                            npos[0], npos[1], npos[2], m_chunk_pos, m_blocks,
+                            neighbor_block);
+
+                        if (is_face_culled(cur_id, nb_id)) {
+                            mask[vi * u + ui] = {};
+                        } else {
+                            mask[vi * u + ui] = {cur_id, face_idx};
+                        }
+                    }
+                }
+
+                // ── 2. Greedy Merge ──────────────────────────────────────
+                std::fill(visited, visited + u * v, false);
+
+                for (int vi = 0; vi < v; vi++) {
+                    for (int ui = 0; ui < u; ui++) {
+                        if (visited[vi * u + ui])
+                            continue;
+                        FaceKey cur = mask[vi * u + ui];
+                        if (!cur.valid())
+                            continue;
+
+                        // Extend width in the u direction
+                        int w = 1;
+                        while (ui + w < u && !visited[vi * u + (ui + w)] &&
+                               mask[vi * u + (ui + w)] == cur) {
+                            w++;
+                        }
+
+                        // Extend height in the v direction
+                        int h = 1;
+                        bool can_expand = true;
+                        while (vi + h < v && can_expand) {
+                            for (int k = 0; k < w; k++) {
+                                int idx = (vi + h) * u + (ui + k);
+                                if (visited[idx] || mask[idx] != cur) {
+                                    can_expand = false;
+                                    break;
+                                }
+                            }
+                            if (can_expand)
+                                h++;
+                        }
+
+                        // mark visited
+                        for (int dv = 0; dv < h; dv++)
+                            for (int du = 0; du < w; du++)
+                                visited[(vi + dv) * u + (ui + du)] = true;
+
+                        // output quad
+                        emit_quad(axis, face_dir, layer, ui, vi, w, h, u_axis,
+                                  v_axis, cur);
+                    }
+                }
+            }
+        }
+    }
+
+    for (int x = 0; x < CHUNK_SIZE; x++) {
+        for (int y = 0; y < WORLD_SIZE_Y; y++) {
+            for (int z = 0; z < CHUNK_SIZE; z++) {
+                BlockType id = m_blocks[index(x, y, z)];
+                if (id != 0 && BlockManager::is_cross_plane(id)) {
+                    int world_x = x + m_chunk_pos.x * CHUNK_SIZE;
+                    int world_z = z + m_chunk_pos.z * CHUNK_SIZE;
+                    gen_cross_plane_vertices(world_x, y, world_z, id);
+                }
+            }
+        }
+    }
+}
+void ClientChunk::emit_quad(int axis, int face_dir, int layer, int i, int j,
+                            int w, int h, int u_axis, int v_axis, FaceKey key) {
+    float axis_val = (float)(layer + (face_dir > 0 ? 1 : 0));
+    float wx_base = (float)(m_chunk_pos.x * CHUNK_SIZE);
+    float wz_base = (float)(m_chunk_pos.z * CHUNK_SIZE);
+
+    // Offsets of the four corners along the u_axis/v_axis
+    int su[4] = {0, w, w, 0};
+    int sv[4] = {0, 0, h, h};
+
+    // Each face's UV: directly read from the four corners of TEX_COORDS, then
+    // scaled by w/h TEX_COORDS vertex order: 0=BL, 1=TL, 2=TR, 3=TR, 4=BR, 5=BL
+    // (two triangles) Four unique corners correspond to indices: BL=0, TL=1,
+    // TR=2, BR=4 Extract the UVs of the four corners from TEX_COORDS (unique
+    // corners after removing duplicate vertices) Vertices 0,1,2,4 correspond to
+    // BL, TL, TR, BR
+    float u0 = TEX_COORDS[key.face][0][0]; // BL.u
+    float v0 = TEX_COORDS[key.face][0][1]; // BL.v
+    float u1 = TEX_COORDS[key.face][4][0]; // BR.u
+    float v1 = TEX_COORDS[key.face][4][1]; // BR.v
+    float u3 = TEX_COORDS[key.face][1][0]; // TL.u
+    float v3 = TEX_COORDS[key.face][1][1]; // TL.v
+
+    float du_u = u1 - u0; // Change in u when su increases (per block)
+    float dv_u = v1 - v0;
+    float du_v = u3 - u0; // Change in u when sv increases
+    float dv_v = v3 - v0;
+
+    float uvs[4][2] = {
+        {u0, v0},                                     // (0,  0 )
+        {u0 + du_u * (float)w, v0 + dv_u * (float)w}, // (w,  0 )
+        {u0 + du_u * (float)w + du_v * (float)h,
+         v0 + dv_u * (float)w + dv_v * (float)h},     // (w,  h )
+        {u0 + du_v * (float)h, v0 + dv_v * (float)h}, // (0,  h )
+    };
+
+    int tri[6] = {0, 1, 2, 0, 2, 3};
+
+    float pos[4][3];
+    for (int c = 0; c < 4; c++) {
+        pos[c][axis] = axis_val;
+        pos[c][u_axis] = (float)(i + su[c]);
+        pos[c][v_axis] = (float)(j + sv[c]);
+        pos[c][0] += wx_base;
+        pos[c][2] += wz_base;
+    }
+
+    float layer_id = (float)(key.block_id * 6 + key.face);
+    float roughness = BlockManager::roughness(key.block_id);
+    int buf = choose_buf(key.block_id);
+
+    for (int vi = 0; vi < 6; vi++) {
+        int c = tri[vi];
+        Vertex3D vex = {
+            pos[c][0],
+            pos[c][1],
+            pos[c][2],
+            uvs[c][0],
+            uvs[c][1],
+            layer_id,
+            NORMALS[key.face][0][0],
+            NORMALS[key.face][0][1],
+            NORMALS[key.face][0][2],
+            roughness,
+            TANGENTS[key.face][0][0],
+            TANGENTS[key.face][0][1],
+            TANGENTS[key.face][0][2],
+        };
+        m_vertex_data[buf].m_vertices.emplace_back(vex);
+    }
+}
+
+void ClientChunk::gen_cross_plane_vertices(int world_x, int world_y,
+                                           int world_z, BlockType id) {
+
+    if (!BlockManager::is_cross_plane(id)) {
+        Logger::warn("Block {} {} {} id {} is not cross plane", world_x,
+                     world_y, world_z, id);
+        return;
+    }
+    for (int face = 0; face < 2; face++) {
+        for (int i = 0; i < 6; i++) {
+            Vertex3D vex = {
+                CROSS_VERTICES_POS[face][i][0] + (float)world_x * 1.0f,
+                CROSS_VERTICES_POS[face][i][1] + (float)world_y * 1.0f,
+                CROSS_VERTICES_POS[face][i][2] + (float)world_z * 1.0f,
+                CROSS_TEX_COORDS[face][i][0],
+                CROSS_TEX_COORDS[face][i][1],
+                static_cast<float>(BlockManager::cross_plane_index(id)),
+                CROSS_NORMALS[face][i][0],
+                CROSS_NORMALS[face][i][1],
+                CROSS_NORMALS[face][i][2],
+                BlockManager::roughness(id),
+                CROSS_TANGENTS[face][i][0],
+                CROSS_TANGENTS[face][i][1],
+                CROSS_TANGENTS[face][i][2]
+
+            };
+            m_vertex_data[1].m_vertices.emplace_back(vex);
+        }
+    }
+}
+
+void ClientChunk::receive_chunk(const ChunkDataRsp& data) {
+    OptionalBlockVectorArray neighbor;
+
+    for (int i = 0; i < 4; i++) {
+        neighbor[i] = std::nullopt;
+    }
+
+    if (data.chunk_blocks_size() != BLOCK_SIZE) {
+        Logger::error("Bad Chunk, size {}", data.chunk_blocks_size());
+        return;
+    }
+
+    m_blocks.reserve(BLOCK_SIZE);
+
+    for (const auto& b : data.chunk_blocks()) {
+        m_blocks.push_back(static_cast<BlockType>(b));
+    }
+    // temp neighbor block data
+    if (data.neighbor_blocks_1_size() == BLOCK_SIZE) {
+        neighbor[0] = std::vector<BlockType>();
+        neighbor[0]->reserve(BLOCK_SIZE);
+        for (const auto& b : data.chunk_blocks()) {
+            neighbor[0]->push_back(static_cast<BlockType>(b));
+        }
+    }
+    if (data.neighbor_blocks_2_size() == BLOCK_SIZE) {
+        neighbor[1] = std::vector<BlockType>();
+        neighbor[1]->reserve(BLOCK_SIZE);
+        for (const auto& b : data.chunk_blocks()) {
+            neighbor[1]->push_back(static_cast<BlockType>(b));
+        }
+    }
+    if (data.neighbor_blocks_3_size() == BLOCK_SIZE) {
+        neighbor[2] = std::vector<BlockType>();
+        neighbor[2]->reserve(BLOCK_SIZE);
+        for (const auto& b : data.chunk_blocks()) {
+            neighbor[2]->push_back(static_cast<BlockType>(b));
+        }
+    }
+    if (data.neighbor_blocks_3_size() == BLOCK_SIZE) {
+        neighbor[3] = std::vector<BlockType>();
+        neighbor[3]->reserve(BLOCK_SIZE);
+        for (const auto& b : data.chunk_blocks()) {
+            neighbor[3]->push_back(static_cast<BlockType>(b));
+        }
+    }
+
+    gen_vertex_data(neighbor);
+}
+
+} // namespace Cubed

src/gameplay/server_world.cpp

@@ -437,6 +437,7 @@ void ServerWorld::handle_chunk_req(const std::string& uuid, ChunkPos pos) {
             return;
         }
         rsq.set_chunk_seed(it->second.seed());
+        rsq.set_biome_type(std::to_underlying(it->second.biome()));
         auto* blocks = rsq.mutable_chunk_blocks();
         auto& chunk_blocks = it->second.get_chunk_blocks();
         blocks->Assign(chunk_blocks.begin(), chunk_blocks.end());

src/proto/world/chunk_data.proto

@@ -10,9 +10,10 @@ message ChunkDataReq {
 message ChunkDataRsp {
     ChunkPos pos = 1;
     uint32 chunk_seed = 2;
-    repeated uint32 chunk_blocks = 3 [packed=true];
-    repeated uint32 neighbor_blocks_1 = 4 [packed=true];
-    repeated uint32 neighbor_blocks_2 = 5 [packed=true];
-    repeated uint32 neighbor_blocks_3 = 6 [packed=true];
-    repeated uint32 neighbor_blocks_4 = 7 [packed=true];
+    int32 biome_type = 3;
+    repeated uint32 chunk_blocks = 4 [packed=true];
+    repeated uint32 neighbor_blocks_1 = 5 [packed=true];
+    repeated uint32 neighbor_blocks_2 = 6 [packed=true];
+    repeated uint32 neighbor_blocks_3 = 7 [packed=true];
+    repeated uint32 neighbor_blocks_4 = 8 [packed=true];
 }