refactor: world generation (#17)

* refactor: use TBB for concurrent hash maps and parallelize chunk processing

* fix: tbb link fail

* refactor(chunk): remove biome check for caves in rivers and oceans

* refactor(random): replace std distributions with custom implementations

Avoid overhead and platform-dependent behavior of `<random>` distributions by using direct engine operations and integer arithmetic. This ensures deterministic, cross-platform results and improves performance.

* refactor(generation): use chunk seed for cave and river paths

- Use per-chunk seed instead of global path_id for cave and river generation.
- Remove unused m_sum variables and m_path_id members.
- Clamp river yaw within 10 degrees of initial direction.
- Fix river radius interpolation (use t instead of 1-t).
- Lower sea level from 64 to 63.

CMakeLists.txt

@@ -58,6 +58,21 @@ if (WIN32)
     if(TARGET freetype)
     add_library(Freetype::Freetype ALIAS freetype)
     endif()
+    set(_BUILD_SHARED_LIBS_SAVED ${BUILD_SHARED_LIBS})
+    set(BUILD_SHARED_LIBS ON)
+
+    FetchContent_Declare(
+    onetbb                           
+    GIT_REPOSITORY https://github.com/uxlfoundation/oneTBB.git
+    GIT_TAG v2023.0.0
+    )
+    set(BUILD_TESTING OFF CACHE BOOL "Build tests" FORCE)
+    set(TBB_TEST OFF CACHE BOOL "Build TBB tests" FORCE)
+    FetchContent_MakeAvailable(onetbb)
+
+    set(BUILD_SHARED_LIBS ${_BUILD_SHARED_LIBS_SAVED})
+    unset(_BUILD_SHARED_LIBS_SAVED)
+
 endif()
 
 FetchContent_Declare(
@@ -83,7 +98,6 @@ FetchContent_MakeAvailable(tomlplusplus)
 
 add_subdirectory(third_party/imgui)
 
-
 set(INCLUDE_DIR ${PROJECT_SOURCE_DIR}/include)
 
 add_executable(${PROJECT_NAME}
@@ -123,6 +137,8 @@ add_executable(${PROJECT_NAME}
     src/gameplay/river_worm.cpp
     src/gameplay/river_path.cpp
     src/block.cpp
+    src/gameplay/vertex_data.cpp
+    src/gameplay/builders/ocean_builder.cpp
 )
 
 if(CMAKE_BUILD_TYPE STREQUAL "Debug")
@@ -162,10 +178,11 @@ target_link_libraries(${PROJECT_NAME}
         Freetype::Freetype
         tomlplusplus::tomlplusplus
         imgui
+        tbb
 )
 
 if (CMAKE_CXX_COMPILER_ID STREQUAL "GNU" OR CMAKE_CXX_COMPILER_ID STREQUAL "Clang")
-    target_link_libraries(${PROJECT_NAME} PRIVATE tbb)
+#    target_link_libraries(${PROJECT_NAME} PRIVATE tbb)
 endif()
 
 if (UNIX AND NOT APPLE)
@@ -185,3 +202,19 @@ if (UNIX AND NOT APPLE)
 
     target_compile_options(${PROJECT_NAME} PRIVATE ${EGL_CFLAGS_OTHER} ${Wayland_CFLAGS_OTHER})
 endif()
+
+if (WIN32)
+    foreach(TBB_LIB IN ITEMS tbb tbbmalloc tbbmalloc_proxy)
+        if(TARGET ${TBB_LIB})
+            add_custom_command(
+                TARGET ${PROJECT_NAME} POST_BUILD
+                COMMAND ${CMAKE_COMMAND} -E copy_if_different
+                    $<TARGET_FILE:${TBB_LIB}>
+                    $<TARGET_FILE_DIR:${PROJECT_NAME}>
+                COMMENT "Copying ${TBB_LIB}.dll"
+            )
+        else()
+            message(STATUS "Target ${TBB_LIB} not found, skipping copy")
+        endif()
+    endforeach()
+endif()

assets/data/block/air.toml

@@ -1,7 +1,10 @@
 id = 0
+is_blend = false
 is_cross_plane = false
+is_discard = true
 is_gas = true
 is_liquid = false
 is_passable = true
+is_transitional = false
 is_transparent = true
 name = 'air'

assets/data/block/dirt.toml

@@ -1,7 +1,10 @@
 id = 2
+is_blend = false
 is_cross_plane = false
+is_discard = false
 is_gas = false
 is_liquid = false
 is_passable = false
+is_transitional = true
 is_transparent = false
 name = 'dirt'

assets/data/block/grass.toml

@@ -1,7 +1,10 @@
 id = 9
+is_blend = false
 is_cross_plane = true
+is_discard = true
 is_gas = false
 is_liquid = false
 is_passable = true
+is_transitional = false
 is_transparent = true
 name = 'grass'

assets/data/block/grass_block.toml

@@ -1,7 +1,10 @@
 id = 1
+is_blend = false
 is_cross_plane = false
+is_discard = false
 is_gas = false
 is_liquid = false
 is_passable = false
+is_transitional = true
 is_transparent = false
 name = 'grass_block'

assets/data/block/leaf.toml

@@ -1,7 +1,10 @@
 id = 6
+is_blend = false
 is_cross_plane = false
+is_discard = true
 is_gas = false
 is_liquid = false
 is_passable = false
+is_transitional = false
 is_transparent = true
 name = 'leaf'

assets/data/block/log.toml

@@ -1,7 +1,10 @@
 id = 5
+is_blend = false
 is_cross_plane = false
+is_discard = false
 is_gas = false
 is_liquid = false
 is_passable = false
+is_transitional = false
 is_transparent = false
 name = 'log'

assets/data/block/sand.toml

@@ -1,7 +1,10 @@
 id = 4
+is_blend = false
 is_cross_plane = false
+is_discard = false
 is_gas = false
 is_liquid = false
 is_passable = false
+is_transitional = true
 is_transparent = false
 name = 'sand'

assets/data/block/snowy_grass_block.toml

@@ -1,7 +1,10 @@
 id = 8
+is_blend = false
 is_cross_plane = false
+is_discard = false
 is_gas = false
 is_liquid = false
 is_passable = false
+is_transitional = true
 is_transparent = false
 name = 'snowy_grass_block'

assets/data/block/stone.toml

@@ -1,7 +1,10 @@
 id = 3
+is_blend = false
 is_cross_plane = false
+is_discard = false
 is_gas = false
 is_liquid = false
 is_passable = false
+is_transitional = true
 is_transparent = false
 name = 'stone'

assets/data/block/template.toml

@@ -5,3 +5,6 @@ is_gas = false
 is_passable = false
 is_cross_plane = false
 is_transparent = false
+is_discard = false
+is_blend = false
+is_transitional = false

assets/data/block/water.toml

@@ -1,7 +1,10 @@
 id = 7
+is_blend = true
 is_cross_plane = false
+is_discard = false
 is_gas = false
 is_liquid = true
 is_passable = true
+is_transitional = false
 is_transparent = true
 name = 'water'

assets/shaders/block_accumulation_f_shader.glsl

@@ -0,0 +1,28 @@
+#version 460
+
+layout (location = 0) out vec4 accum;
+layout (location = 1) out float reveal;
+
+in vec2 tc;
+flat in int tex_layer;
+in float v_depth;
+layout (binding = 0) uniform sampler2DArray samp;
+
+float weight(float z, float a) {
+    float intermediate = 0.03 / (1e-5 + pow(z / 200.0, 4.0));
+    
+    return a * clamp(intermediate, 1e-2, 3e2);
+}
+
+void main() {
+    vec4 color = texture(samp, vec3(tc, tex_layer));
+    float alpha = color.a;
+    if (alpha < 1e-4) discard;
+
+
+    float w = weight(v_depth, alpha);
+
+    accum = vec4(color.rgb * alpha * w, alpha * w);
+
+    reveal = alpha;
+}

assets/shaders/block_accumulation_v_shader.glsl

@@ -0,0 +1,21 @@
+#version 460
+
+layout (location = 0) in vec3 pos;
+layout (location = 1) in vec2 texCoord;
+layout (location = 2) in float layer;
+out vec2 tc;
+flat out int tex_layer;
+out float v_depth;
+
+uniform mat4 mv_matrix;
+uniform mat4 proj_matrix;
+
+
+
+void main(void) {
+    vec4 view_pos = mv_matrix * vec4(pos, 1.0);
+    gl_Position = proj_matrix * view_pos;
+    tc = texCoord;
+    tex_layer = int(layer);
+    v_depth = -view_pos.z;
+}

assets/shaders/block_composite_f_shader.glsl

@@ -0,0 +1,19 @@
+#version 460
+
+uniform sampler2D u_accumTex;
+uniform sampler2D u_revealTex;
+in vec2 TexCoord;
+out vec4 FragColor;
+
+void main() {
+    vec4 a = texture(u_accumTex, TexCoord);
+    float r = texture(u_revealTex, TexCoord).r;
+
+    if (a.a < 1e-4) discard;
+
+    vec3 color = a.rgb / max(a.a, 1e-5);
+    float transmittance = r;
+    float opacity = 1.0 - transmittance;
+
+    FragColor = vec4(color * opacity, opacity);
+}

assets/shaders/block_composite_v_shader.glsl

@@ -0,0 +1,11 @@
+#version 460
+
+layout (location = 0) in vec2 pos;
+layout (location = 1) in vec2 texCoord;
+
+out vec2 TexCoord;
+
+void main() {
+    gl_Position = vec4(pos.x, pos.y, 0.0, 1.0);
+    TexCoord = texCoord;
+}

assets/shaders/block_f_shader.glsl

@@ -8,7 +8,7 @@ layout (binding = 0) uniform sampler2DArray samp;
 
 void main(void) {
     color = texture(samp, vec3(tc, tex_layer));
-    if (color.a < 0.1) {
+    if (color.a < 0.8) {
         discard;
     }
     //color = varyingColor;

include/Cubed/constants.hpp

@@ -6,7 +6,7 @@ namespace Cubed {
 
 constexpr int WORLD_SIZE_Y = 256;
 constexpr int CHUNK_SIZE = 16;
-constexpr int SEA_LEVEL = 64;
+constexpr int SEA_LEVEL = 63;
 
 constexpr int MAX_UI_NUM = 1;
 constexpr int MAX_BLOCK_STATUS = 1;

include/Cubed/gameplay/biome.hpp

@@ -15,6 +15,7 @@ enum class BiomeType {
     MOUNTAIN,
     RIVER,
     SNOWY_PLAIN,
+    OCEAN,
     NONE
 };
 

include/Cubed/gameplay/block.hpp

@@ -47,11 +47,17 @@ struct BlockData {
     bool is_passable = false;
     bool is_cross_plane = false;
     bool is_transparent = false;
+
+    bool is_discard = false;
+    bool is_blend = false;
+    bool is_transitional = false;
     BlockData(BlockType b_id, std::string_view b_name, bool liquid,
-              bool passable, bool cross_plane, bool transparent, bool gas)
+              bool passable, bool cross_plane, bool transparent, bool gas,
+              bool discard, bool blend, bool transitional)
         : name(b_name), id(b_id), is_liquid(liquid), is_gas(gas),
           is_passable(passable), is_cross_plane(cross_plane),
-          is_transparent(transparent) {}
+          is_transparent(transparent), is_discard(discard), is_blend(blend),
+          is_transitional(transitional) {}
 };
 
 class BlockManager {
@@ -69,6 +75,10 @@ public:
     static bool is_cross_plane(BlockType id);
     static bool is_transparent(BlockType id);
     static bool is_passable(BlockType id);
+
+    static bool is_discard(BlockType id);
+    static bool is_blend(BlockType id);
+    static bool is_transitional(BlockType id);
     static BlockType cross_plane_index(BlockType id);
 
 private:

include/Cubed/gameplay/builders/biome_builder.hpp

@@ -9,6 +9,7 @@ public:
     virtual ChunkGenerator& get_chunk_generator() = 0;
     virtual void build_biome() = 0;
     virtual void build_vegetation() = 0;
+    void ocean_water_build();
 
 protected:
     void build_bottom();

include/Cubed/gameplay/builders/ocean_builder.hpp

@@ -0,0 +1,23 @@
+#pragma once
+
+#pragma once
+
+#include "Cubed/gameplay/builders/biome_builder.hpp"
+namespace Cubed {
+
+class ChunkGenerator;
+
+class OceanBuilder : public BiomeBuilder {
+public:
+    OceanBuilder(ChunkGenerator& chunk_generator);
+    void build_biome() override;
+    ChunkGenerator& get_chunk_generator() override;
+    void build_vegetation() override;
+
+private:
+    ChunkGenerator& m_chunk_generator;
+
+    void build_blocks();
+};
+
+} // namespace Cubed

include/Cubed/gameplay/cave_carver.hpp

@@ -1,10 +1,14 @@
 #pragma once
 #include "Cubed/gameplay/cave_path.hpp"
+
+#include <tbb/concurrent_hash_map.h>
 namespace Cubed {
 class CaveCarver {
+    using CaveHashMap = tbb::concurrent_hash_map<unsigned, CavePath>;
+
 public:
     CaveCarver();
-    std::unordered_map<unsigned, CavePath>& paths();
+    CaveHashMap& paths();
     void init(unsigned world_seed);
     void reload(unsigned world_seed);
     void add_path(const glm::vec3& pos, unsigned chunk_seed);
@@ -15,9 +19,8 @@ public:
     float& cave_probability();
 
 private:
-    std::unordered_map<unsigned, CavePath> m_paths;
+    CaveHashMap m_paths;
     unsigned m_seed = 0;
-    int m_sum = 0;
     Random m_random;
     float m_cave_probability = 0.035f;
 };

include/Cubed/gameplay/cave_path.hpp

@@ -5,12 +5,16 @@
 #include "Cubed/tools/cubed_random.hpp"
 
 #include <glm/glm.hpp>
-#include <unordered_set>
+#include <tbb/concurrent_hash_map.h>
 namespace Cubed {
 
 class CavePath {
+    using ChunkPosSet =
+        tbb::concurrent_hash_map<ChunkPos, bool, ChunkPos::TBBHash>;
+
 public:
-    CavePath(unsigned int world_seed, int path_id, const glm::vec3& start_pos);
+    CavePath(unsigned int chunk_seed, unsigned world_seed,
+             const glm::vec3& start_pos);
     const std::vector<PathPoint>& points() const;
     void clear_chunk(const ChunkPos& pos);
     bool is_finished() const;
@@ -34,7 +38,6 @@ private:
     static inline int m_step_min = 10;
     static inline int m_step_max = 400;
 
-    int m_path_id = 0;
     unsigned int m_seed = 0;
     float m_yaw = 0.0f;
     float m_pitch = 0.0f;
@@ -44,7 +47,7 @@ private:
     Random m_random;
 
     std::vector<PathPoint> m_points;
-    std::unordered_set<ChunkPos, ChunkPos::Hash> m_pending_chunks;
+    ChunkPosSet m_pending_chunks;
     void collect_path_points();
     void precompute_chunk_coverage();
 };

include/Cubed/gameplay/chunk.hpp

@@ -4,7 +4,7 @@
 #include "Cubed/gameplay/block.hpp"
 #include "Cubed/gameplay/chunk_generator.hpp"
 #include "Cubed/gameplay/chunk_pos.hpp"
-#include "Cubed/primitive_data.hpp"
+#include "Cubed/gameplay/vertex_data.hpp"
 
 #include <atomic>
 #include <mutex>
@@ -14,16 +14,15 @@ class World;
 // if want to use, do init_chunk(), gen_vertex_data() and
 class Chunk {
 private:
+    using OptionalBlockVectorArray =
+        std::array<std::optional<std::vector<BlockType>>, 4>;
     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 VERTEX_DATA_SUM = 4;
     std::atomic<bool> m_dirty{false};
     std::atomic<bool> m_need_upload{true};
     std::atomic<bool> m_is_on_gen_vertex_data{false};
-    std::atomic<size_t> m_normal_vertices_sum = 0;
-    std::atomic<size_t> m_cross_vertices_sum = 0;
-    std::atomic<size_t> m_transparent_vertices_sum = 0;
     std::atomic<BiomeType> m_biome = BiomeType::PLAIN;
     std::mutex m_vertexs_data_mutex;
 
@@ -34,12 +33,14 @@ private:
     HeightMapArray m_heightmap;
     // the index is a array of block id
     std::vector<BlockType> m_blocks;
-    GLuint m_normal_vbo = 0;
-    GLuint m_cross_plane_vbo = 0;
-    GLuint m_transparent_normal_vbo = 0;
-    std::vector<Vertex> m_normal_vertices;
-    std::vector<Vertex> m_cross_plane_vertices;
-    std::vector<Vertex> m_transparent_normal_vertices;
+
+    /*
+    0 - normal
+    1 - cross_plane
+    2 - normal_discard
+    3 - transparent and blend
+    */
+    std::vector<VertexData> m_vertex_data;
     float frequency = 0.01f;
     float height = 80;
     unsigned m_seed = 0;
@@ -47,9 +48,9 @@ private:
     BiomeConditions m_conditions;
 
     void clear_dirty();
-    void gen_normal_vertices(
-        const std::array<const std::vector<BlockType>*, 4>& neighbor_block);
-    void gen_cross_plane_vertices();
+    void gen_vertices(const OptionalBlockVectorArray& neighbor_block);
+    void gen_cross_plane_vertices(int world_x, int world_y, int world_z,
+                                  BlockType id);
 
 public:
     Chunk(World& world, ChunkPos chunk_pos);
@@ -97,18 +98,20 @@ public:
     //  1 : (-1, 0)
     //  2 : (0, 1)
     //  3 : (0, -1)
-    void gen_vertex_data(
-        const std::array<const std::vector<BlockType>*, 4>& neighbor_block);
+    void gen_vertex_data(const OptionalBlockVectorArray& neighbor_block);
     void upload_to_gpu();
 
-    GLuint get_normal_vbo() const;
+    GLuint get_normal_vao() const;
     size_t get_normal_vertices_sum() const;
 
-    GLuint get_cross_vbo() const;
+    GLuint get_cross_vao() const;
     size_t get_cross_vertices_sum() const;
 
-    GLuint get_transparent_vbo() const;
-    size_t get_transparent_vertices_sum() const;
+    GLuint get_normal_discard_vao() const;
+    size_t get_normal_discard_vertices_sum() const;
+
+    GLuint get_normal_blend_vao() const;
+    size_t get_normal_blend_vertices_sum() const;
 
     bool is_dirty() const;
     void mark_dirty();

include/Cubed/gameplay/chunk_generator.hpp

@@ -4,6 +4,7 @@
 #include "Cubed/gameplay/biome.hpp"
 #include "Cubed/gameplay/block.hpp"
 #include "Cubed/gameplay/builders/biome_builder.hpp"
+#include "Cubed/gameplay/path_point.hpp"
 #include "Cubed/tools/cubed_random.hpp"
 
 #include <atomic>
@@ -45,6 +46,7 @@ public:
     Chunk& chunk();
     Random& random();
     const std::array<BiomeType, 8>& neighbor_biome() const;
+    void ocean_build();
     void generate_cave();
     void generate_river();
 
@@ -60,6 +62,9 @@ private:
     unsigned m_chunk_seed = 0;
 
     void make_biome_builder();
+    void
+    carve_worm(const std::vector<PathPoint>& points, const ChunkPos& chunk_pos,
+               std::function<void(int /*x*/, int /*y*/, int /*z*/)> on_hit);
 };
 
 } // namespace Cubed

include/Cubed/gameplay/chunk_pos.hpp

@@ -16,7 +16,14 @@ struct ChunkPos {
             return h1 ^ (h2 + 0x9e3779b9 + (h1 << 6) + (h1 >> 2));
         }
     };
-
+    struct TBBHash {
+        std::size_t hash(const ChunkPos& p) const {
+            return ChunkPos::Hash{}(p);
+        }
+        bool equal(const ChunkPos& a, const ChunkPos& b) const {
+            return a == b;
+        }
+    };
     ChunkPos operator+(const ChunkPos& pos) const {
         return ChunkPos{x + pos.x, z + pos.z};
     }

include/Cubed/gameplay/river.path.hpp

@@ -5,13 +5,16 @@
 #include "Cubed/tools/cubed_random.hpp"
 
 #include <glm/glm.hpp>
-#include <unordered_set>
+#include <tbb/concurrent_hash_map.h>
 
 namespace Cubed {
 class RiverPath {
+    using ChunkPosSet =
+        tbb::concurrent_hash_map<ChunkPos, bool, ChunkPos::TBBHash>;
 
 public:
-    RiverPath(unsigned int world_seed, int path_id, const glm::vec3& start_pos);
+    RiverPath(unsigned int chunk_seed, unsigned world_seed,
+              const glm::vec3& start_pos);
     const std::vector<PathPoint>& points() const;
     void clear_chunk(const ChunkPos& pos);
     bool is_finished() const;
@@ -32,12 +35,12 @@ private:
     static inline float m_radius_y_max = 8.0f;
     static inline float m_delta_angle_min = -3.0f;
     static inline float m_delta_angle_max = 3.0f;
-    static inline int m_step_min = 150;
+    static inline int m_step_min = 200;
     static inline int m_step_max = 400;
 
-    int m_path_id = 0;
     unsigned int m_seed = 0;
     float m_yaw = 0.0f;
+    float m_initial_yaw = 0.0f;
     float m_pitch = 0.0f;
     int m_step = 0;
     float m_step_len = 1.0f;
@@ -45,7 +48,7 @@ private:
     Random m_random;
 
     std::vector<PathPoint> m_points;
-    std::unordered_set<ChunkPos, ChunkPos::Hash> m_pending_chunks;
+    ChunkPosSet m_pending_chunks;
     void collect_path_points();
     void precompute_chunk_coverage();
 };

include/Cubed/gameplay/river_worm.hpp

@@ -4,13 +4,15 @@
 #include "Cubed/tools/cubed_random.hpp"
 
 #include <glm/glm.hpp>
-#include <unordered_map>
+#include <tbb/concurrent_hash_map.h>
 namespace Cubed {
 
 class RiverWorm {
+    using RiverHashMap = tbb::concurrent_hash_map<unsigned, RiverPath>;
+
 public:
     RiverWorm();
-    std::unordered_map<unsigned, RiverPath>& paths();
+    RiverHashMap& paths();
     void init(unsigned world_seed);
     void reload(unsigned world_seed);
     void add_path(const glm::vec3& pos, unsigned chunk_seed);
@@ -21,9 +23,8 @@ public:
     float& river_probability();
 
 private:
-    std::unordered_map<unsigned, RiverPath> m_paths;
+    RiverHashMap m_paths;
     unsigned m_seed = 0;
-    int m_sum = 0;
     Random m_random;
     float m_probability = 0.01f;
 };

include/Cubed/gameplay/vertex_data.hpp

@@ -0,0 +1,25 @@
+#pragma once
+#include "Cubed/primitive_data.hpp"
+
+#include <atomic>
+#include <glad/glad.h>
+#include <vector>
+namespace Cubed {
+class World;
+struct VertexData {
+    std::vector<Vertex> m_vertices;
+    GLuint m_vbo = 0;
+    GLuint m_vao = 0;
+    std::atomic<std::size_t> m_sum{0};
+    World& m_world;
+    VertexData(World& world);
+    ~VertexData();
+    VertexData(const VertexData&) = delete;
+    VertexData(VertexData&&) noexcept;
+    VertexData& operator=(const VertexData&) = delete;
+    VertexData& operator=(VertexData&&) noexcept;
+
+    void upload();
+    void update_sum();
+};
+} // namespace Cubed

include/Cubed/gameplay/world.hpp

@@ -15,12 +15,14 @@
 namespace Cubed {
 
 struct ChunkRenderSnapshot {
-    GLuint normal_vbo;
+    GLuint normal_vao;
     size_t normal_vertices_count;
-    GLuint cross_vbo;
+    GLuint cross_vao;
     size_t cross_vertices_count;
-    GLuint transparent_vbo;
-    size_t transparent_vertices_count;
+    GLuint normal_discard_vao;
+    size_t normal_discard_vertices_count;
+    GLuint normal_blend_vao;
+    size_t normal_blend_vertices_count;
     glm::vec3 center;
     glm::vec3 half_extents;
 };
@@ -29,8 +31,10 @@ class Player;
 class TextureManager;
 class World {
 private:
+    using OptionalBlockVectorArray =
+        std::array<std::optional<std::vector<BlockType>>, 4>;
     using ChunkPtrUpdateList = std::vector<std::pair<ChunkPos, Chunk*>>;
-    using ChunkUpdateList = std::vector<std::pair<ChunkPos, Chunk>>;
+    using ChunkPairVector = std::vector<std::pair<ChunkPos, Chunk>>;
     using ConstChunkMap =
         std::unordered_map<ChunkPos, const Chunk*, ChunkPos::Hash>;
     using ChunkPosSet = std::unordered_set<ChunkPos, ChunkPos::Hash>;
@@ -45,8 +49,10 @@ private:
     std::mutex m_gen_signal_mutex;
     std::mutex m_new_chunk_queue_mutex;
     std::mutex m_delete_vbo_mutex;
+    std::mutex m_delete_vao_mutex;
     std::mutex m_gen_player_pos_mutex;
     std::vector<GLuint> m_pending_delete_vbo;
+    std::vector<GLuint> m_pending_delete_vao;
     std::condition_variable m_gen_cv;
     std::atomic<bool> m_gen_running{false};
     std::atomic<bool> m_need_gen_chunk{false};
@@ -66,14 +72,16 @@ private:
 
     void gen_chunks_internal();
     void sync_player_pos(glm::vec3& player_pos);
-    void compute_required_chunks(ChunkPosSet& required_chunks,
-                                 ChunkHashMap& temp_neighbor);
+    void
+    compute_required_chunks(ChunkPosSet& required_chunks,
+                            ChunkPairVector& temp_neighbor,
+                            std::vector<ChunkPos>& need_gen_temp_chunks_pos);
     void sync_and_collect_missing_chunks(std::vector<ChunkPos>&,
                                          const ChunkPosSet&);
     void
     build_neighbor_context_for_new_chunks(ConstChunkMap& new_chunks_neighbor,
                                           ChunkPtrUpdateList& affected_neighbor,
-                                          const ChunkUpdateList& new_chunks);
+                                          const ChunkPairVector& new_chunks);
     void build_neighbor_context_for_affected_neighbors(ChunkPtrUpdateList&,
                                                        ConstChunkMap&);
 
@@ -90,9 +98,6 @@ public:
 
     Player& get_player(const std::string& name);
     void init_world();
-    bool is_aabb_in_frustum(const glm::vec3& center,
-                            const glm::vec3& half_extents);
-
     int get_block(const glm::ivec3& block_pos) const;
     bool is_solid(const glm::ivec3& block_pos) const;
     bool can_pass_block(const glm::ivec3& block_pos) const;
@@ -100,15 +105,12 @@ public:
     static ChunkPos chunk_pos(int world_x, int world_z);
 
     void need_gen();
-    void render(const glm::mat4& mvp_matrix,
-                const TextureManager& texture_manager,
-                const glm::vec3& camera_pos);
 
     void set_block(const glm::ivec3& pos, unsigned id);
     void update(float delta_time);
 
     void push_delete_vbo(GLuint vbo);
-
+    void push_delete_vao(GLuint vao);
     void hot_reload();
 
     void rebuild_world();
@@ -121,6 +123,8 @@ public:
 
     CaveCarver& cave_carcer();
     RiverWorm& river_worm();
+    std::vector<glm::vec4>& planes();
+    std::vector<ChunkRenderSnapshot>& render_snapshots();
 };
 
 } // namespace Cubed

include/Cubed/renderer.hpp

@@ -15,7 +15,7 @@ class World;
 class DevPanel;
 class Renderer {
 public:
-    constexpr static int NUM_VAO = 6;
+    constexpr static int NUM_VAO = 7;
 
     Renderer(const Camera& camera, World& world,
              const TextureManager& texture_manager, DevPanel& dev_panel);
@@ -40,6 +40,9 @@ private:
 
     float m_delta_time = 0.0f;
 
+    float m_width = 0.0f;
+    float m_height = 0.0f;
+
     glm::mat4 m_p_mat, m_v_mat, m_m_mat, m_mv_mat, m_mvp_mat;
 
     GLuint m_mv_loc = 0;
@@ -55,15 +58,27 @@ private:
     GLuint m_screen_texture = 0;
     GLuint m_depth_render_buffer = 0;
 
+    GLuint m_oit_fbo = 0;
+    GLuint m_accum_texture = 0;
+    GLuint m_reveal_texture = 0;
+    GLuint m_oit_depth_render_buffer = 0;
     GLuint m_quad_vbo = 0;
 
     glm::mat4 m_ui_proj;
     glm::mat4 m_ui_m_matrix;
     std::unordered_map<std::size_t, Shader> m_shaders;
+
+    /*
+    0 - quad vao
+    1 - sky vao
+    2 - outline vao
+    3 - ui vao
+    4 - text vao
+    */
     std::vector<GLuint> m_vao;
     std::vector<Vertex2D> m_ui;
 
-    void init_underwater();
+    void init_quad();
     void init_text();
 
     void render_outline();

include/Cubed/tools/cubed_hash.hpp

@@ -7,7 +7,17 @@ namespace HASH {
 inline std::size_t str(std::string_view value) {
     return std::hash<std::string_view>{}(value);
 }
-inline uint32_t mix_hash(int32_t a, int32_t b, uint32_t fixed_seed) {
+inline uint32_t combine_32(uint32_t seed, uint32_t v) {
+    seed ^= v + 0x9e3779b9 + (seed << 6) + (seed >> 2);
+    return seed;
+}
+inline uint32_t chunk_seed_hash(int32_t a, int32_t b, uint32_t fixed_seed) {
+    uint32_t seed =
+        combine_32(combine_32(fixed_seed, (uint32_t)a), (uint32_t)b);
+    return seed;
+}
+/*
+inline uint32_t chunk_seed_hash(int32_t a, int32_t b, uint32_t fixed_seed) {
     uint32_t h = fixed_seed;
 
     h ^= (uint32_t)a * 0xcc9e2d51u;
@@ -27,10 +37,8 @@ inline uint32_t mix_hash(int32_t a, int32_t b, uint32_t fixed_seed) {
 
     return h;
 }
-inline uint32_t combine_32(uint32_t seed, uint32_t v) {
-    seed ^= v + 0x9e3779b9 + (seed << 6) + (seed >> 2);
-    return seed;
-}
+    */
+
 } // namespace HASH
 
 } // namespace Cubed

include/Cubed/tools/math_tools.hpp

@@ -9,6 +9,9 @@ void extract_frustum_planes(const glm::mat4& mvp_matrix,
                             std::vector<glm::vec4>& planes);
 
 float smootherstep(float edge0, float edge1, float x);
+bool is_aabb_in_frustum(const glm::vec3& center, const glm::vec3& half_extents,
+                        const std::vector<glm::vec4>& planes);
+float deterministic_random(int x, int z, uint64_t seed);
 } // namespace Math
 
 } // namespace Cubed

src/block.cpp

@@ -90,6 +90,27 @@ bool BlockManager::is_passable(BlockType id) {
     return m_datas[id].is_passable;
 }
 
+bool BlockManager::is_discard(BlockType id) {
+    if (id >= sums()) {
+        Logger::error("Id {}, is Over The Max Id", id, sums() - 1);
+        return m_datas[0].is_discard;
+    }
+    return m_datas[id].is_discard;
+}
+bool BlockManager::is_blend(BlockType id) {
+    if (id >= sums()) {
+        Logger::error("Id {}, is Over The Max Id", id, sums() - 1);
+        return m_datas[0].is_blend;
+    }
+    return m_datas[id].is_blend;
+}
+bool BlockManager::is_transitional(BlockType id) {
+    if (id >= sums()) {
+        Logger::error("Id {}, is Over The Max Id", id, sums() - 1);
+        return m_datas[0].is_transitional;
+    }
+    return m_datas[id].is_transitional;
+}
 void BlockManager::init() {
     fs::path data_path{block_data_dir};
 
@@ -125,8 +146,12 @@ void BlockManager::init() {
         auto is_cross_plane = safe_get_value(block, "is_cross_plane", false);
         auto is_transparent = safe_get_value(block, "is_transparent", false);
         auto is_gas = safe_get_value(block, "is_gas", false);
+        auto is_discard = safe_get_value(block, "is_discard", false);
+        auto is_blend = safe_get_value(block, "is_blend", false);
+        auto is_transitional = safe_get_value(block, "is_transitional", false);
         m_datas.emplace_back(*id, *name, *is_liquid, *is_passable,
-                             *is_cross_plane, *is_transparent, *is_gas);
+                             *is_cross_plane, *is_transparent, *is_gas,
+                             *is_discard, *is_blend, *is_transitional);
     }
     std::sort(
         m_datas.begin(), m_datas.end(),

src/gameplay/biome.cpp

@@ -62,6 +62,10 @@ std::string get_biome_str(BiomeType biome) {
         break;
     case SNOWY_PLAIN:
         str = "Snowy Plain";
+        break;
+    case OCEAN:
+        str = "Ocean";
+        break;
     case NONE:
         str = "Unknown";
         break;
@@ -190,6 +194,9 @@ BiomeType determine_biome(const BiomeConditions& conditions) {
     if (conditions.mountainous > 0.75) {
         return MOUNTAIN;
     }
+    if (conditions.mountainous < 0.25) {
+        return OCEAN;
+    }
     auto temp = conditions.temp;
     auto humid = conditions.humid;
     if (temp < 0.5) {

src/gameplay/builders/biome_builder.cpp

@@ -39,4 +39,23 @@ void BiomeBuilder::place_grass() {
         }
     }
 }
+
+void BiomeBuilder::ocean_water_build() {
+    ChunkGenerator& chunk_generator = get_chunk_generator();
+    Chunk& chunk = chunk_generator.chunk();
+    auto& blocks = chunk.blocks();
+    const auto& heightmap = chunk.get_heightmap();
+
+    for (int x = 0; x < SIZE_X; ++x) {
+        for (int z = 0; z < SIZE_Z; ++z) {
+            int height = heightmap[x][z];
+            if (height <= SEA_LEVEL) {
+                for (int y = height; y <= SEA_LEVEL; y++) {
+                    blocks[Chunk::index(x, y, z)] = 7;
+                }
+            }
+        }
+    }
+}
+
 } // namespace Cubed

src/gameplay/builders/ocean_builder.cpp

@@ -0,0 +1,34 @@
+#include "Cubed/gameplay/builders/ocean_builder.hpp"
+
+#include "Cubed/gameplay/chunk.hpp"
+#include "Cubed/gameplay/chunk_generator.hpp"
+namespace Cubed {
+OceanBuilder::OceanBuilder(ChunkGenerator& chunk_generator)
+    : m_chunk_generator(chunk_generator) {}
+
+void OceanBuilder::build_biome() {
+    BiomeBuilder::build_bottom();
+    build_blocks();
+};
+
+void OceanBuilder::build_blocks() {
+    auto& m_chunk = m_chunk_generator.chunk();
+    auto& m_blocks = m_chunk.blocks();
+    auto& m_heightmap = m_chunk.heightmap();
+    for (int x = 0; x < CHUNK_SIZE; x++) {
+        for (int z = 0; z < CHUNK_SIZE; z++) {
+            int height = static_cast<int>(m_heightmap[x][z]);
+            for (int y = 5; y <= height; y++) {
+                m_blocks[Chunk::index(x, y, z)] = 3;
+            }
+        }
+    }
+}
+
+void OceanBuilder::build_vegetation() {}
+
+ChunkGenerator& OceanBuilder::get_chunk_generator() {
+    return m_chunk_generator;
+};
+
+} // namespace Cubed

src/gameplay/cave_carver.cpp

@@ -5,11 +5,10 @@
 namespace Cubed {
 CaveCarver::CaveCarver() {}
 
-std::unordered_map<unsigned, CavePath>& CaveCarver::paths() { return m_paths; }
+CaveCarver::CaveHashMap& CaveCarver::paths() { return m_paths; }
 
 void CaveCarver::init(unsigned world_seed) {
     m_seed = world_seed;
-    m_sum = 0;
     m_random.init(m_seed);
 }
 
@@ -20,16 +19,18 @@ void CaveCarver::reload(unsigned world_seed) {
 }
 
 void CaveCarver::add_path(const glm::vec3& pos, unsigned chunk_seed) {
-    m_paths.emplace(chunk_seed, CavePath{m_seed, m_sum, pos});
-    m_sum++;
+    m_paths.emplace(chunk_seed, CavePath{chunk_seed, m_seed, pos});
 }
 
 void CaveCarver::try_to_add_path(const ChunkPos& chunk_pos,
                                  unsigned chunk_seed) {
-    auto it = m_paths.find(chunk_seed);
-    if (it != m_paths.end()) {
-        return;
+    {
+        CaveHashMap::const_accessor acc;
+        if (m_paths.find(acc, chunk_seed)) {
+            return;
+        }
     }
+
     Random random{chunk_seed};
     if (random.random_bool(static_cast<double>(m_cave_probability))) {
         const int CHUNK_MIN_X = chunk_pos.x * CHUNK_SIZE;
@@ -47,10 +48,17 @@ void CaveCarver::try_to_add_path(const ChunkPos& chunk_pos,
 }
 
 void CaveCarver::cleanup_finished_caves() {
-    std::erase_if(m_paths,
-                  [](const auto& kv) { return kv.second.is_finished(); });
+    std::vector<unsigned int> finished_keys;
+    for (const auto& pair : m_paths) {
+        if (pair.second.is_finished()) {
+            finished_keys.push_back(pair.first);
+        }
+    }
+    for (const auto& key : finished_keys) {
+        m_paths.erase(key);
+    }
 }
 
-int CaveCarver::cave_sum() const { return m_sum; }
+int CaveCarver::cave_sum() const { return m_paths.size(); }
 float& CaveCarver::cave_probability() { return m_cave_probability; }
 } // namespace Cubed

src/gameplay/cave_path.cpp

@@ -6,10 +6,9 @@
 
 #include <algorithm>
 namespace Cubed {
-CavePath::CavePath(unsigned int world_seed, int path_id,
+CavePath::CavePath(unsigned int chunk_seed, unsigned world_seed,
                    const glm::vec3& start_pos) {
-    m_path_id = path_id;
-    m_seed = HASH::combine_32(world_seed, path_id);
+    m_seed = HASH::combine_32(chunk_seed, world_seed);
     m_random.init(m_seed);
     m_yaw = m_random.random_float(0.0f, 360.0f);
     m_pitch = m_random.random_float(-10.0f, 10.0f);
@@ -75,7 +74,8 @@ void CavePath::precompute_chunk_coverage() {
 
         for (int cx = min_cx; cx <= max_cx; ++cx)
             for (int cz = min_cz; cz <= max_cz; ++cz)
-                m_pending_chunks.insert({cx, cz});
+                m_pending_chunks.insert(
+                    std::make_pair(ChunkPos{cx, cz}, false));
     }
 }
 

src/gameplay/chunk.cpp

@@ -9,65 +9,36 @@
 namespace Cubed {
 
 Chunk::Chunk(World& world, ChunkPos chunk_pos)
-    : m_chunk_pos(chunk_pos), m_world(world) {}
-
-Chunk::~Chunk() {
-    if (m_normal_vbo != 0) {
-        m_world.push_delete_vbo(m_normal_vbo);
-    }
-    if (m_cross_plane_vbo != 0) {
-        m_world.push_delete_vbo(m_cross_plane_vbo);
-    }
-    if (m_transparent_normal_vbo != 0) {
-        m_world.push_delete_vbo(m_transparent_normal_vbo);
+    : m_chunk_pos(chunk_pos), m_world(world) {
+    for (int i = 0; i < VERTEX_DATA_SUM; i++) {
+        m_vertex_data.emplace_back(m_world);
     }
 }
 
+Chunk::~Chunk() {}
+
 Chunk::Chunk(Chunk&& 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_normal_vertices_sum(other.m_normal_vertices_sum.load()),
-      m_cross_vertices_sum(other.m_cross_vertices_sum.load()),
-      m_transparent_vertices_sum(other.m_transparent_vertices_sum.load()),
       m_biome(other.m_biome.load()), m_chunk_pos(std::move(other.m_chunk_pos)),
       m_world(other.m_world), m_heightmap(std::move(other.m_heightmap)),
-      m_blocks(std::move(other.m_blocks)), m_normal_vbo(other.m_normal_vbo),
-      m_cross_plane_vbo(other.m_cross_plane_vbo),
-      m_transparent_normal_vbo(other.m_transparent_normal_vbo),
-      m_normal_vertices(std::move(other.m_normal_vertices)),
-      m_cross_plane_vertices(std::move(other.m_cross_plane_vertices)),
-      m_transparent_normal_vertices(
-          std::move(other.m_transparent_normal_vertices)),
-      m_seed(other.m_seed), m_conditions(other.m_conditions) {
-    other.m_normal_vbo = 0;
-    other.m_cross_plane_vbo = 0;
-    other.m_transparent_normal_vbo = 0;
-}
+      m_blocks(std::move(other.m_blocks)),
+      m_vertex_data(std::move(other.m_vertex_data)), m_seed(other.m_seed),
+      m_conditions(other.m_conditions) {}
 
 Chunk& Chunk::operator=(Chunk&& 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_normal_vbo = other.m_normal_vbo;
-    other.m_normal_vbo = 0;
-    m_cross_plane_vbo = other.m_cross_plane_vbo;
-    m_transparent_normal_vbo = other.m_transparent_normal_vbo;
-    other.m_transparent_normal_vbo = 0;
-    other.m_cross_plane_vbo = 0;
+
     m_chunk_pos = std::move(other.m_chunk_pos);
     m_heightmap = std::move(other.m_heightmap);
     m_blocks = std::move(other.m_blocks);
     m_dirty = other.is_dirty();
-    m_normal_vertices = std::move(other.m_normal_vertices);
-    m_cross_plane_vertices = std::move(other.m_cross_plane_vertices);
-    m_transparent_normal_vertices =
-        std::move(other.m_transparent_normal_vertices);
+    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_normal_vertices_sum = other.m_normal_vertices_sum.load();
-    m_cross_vertices_sum = other.m_cross_vertices_sum.load();
-    m_transparent_vertices_sum = other.m_transparent_vertices_sum.load();
     m_seed = other.m_seed;
     m_conditions = other.m_conditions;
     return *this;
@@ -132,36 +103,47 @@ int Chunk::index(const glm::vec3& pos) {
     return Chunk::index(pos.x, pos.y, pos.z);
 }
 
-void Chunk::gen_vertex_data(
-    const std::array<const std::vector<BlockType>*, 4>& neighbor_block) {
+void Chunk::gen_vertex_data(const OptionalBlockVectorArray& neighbor_block) {
     if (m_is_on_gen_vertex_data) {
         return;
     }
     m_is_on_gen_vertex_data = true;
     std::lock_guard lk(m_vertexs_data_mutex);
-    gen_normal_vertices(neighbor_block);
-    gen_cross_plane_vertices();
+
+    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 Chunk::get_normal_vbo() const { return m_normal_vbo; }
+GLuint Chunk::get_normal_vao() const { return m_vertex_data[0].m_vao; }
 
 size_t Chunk::get_normal_vertices_sum() const {
-    if (m_normal_vertices_sum == 0) {
+    if (m_vertex_data[0].m_sum == 0) {
         Logger::warn("m_normal_vertices_sum is 0");
     }
-    return m_normal_vertices_sum.load();
+    return m_vertex_data[0].m_sum.load();
 }
 
-GLuint Chunk::get_cross_vbo() const { return m_cross_plane_vbo; }
+GLuint Chunk::get_cross_vao() const { return m_vertex_data[1].m_vao; }
 size_t Chunk::get_cross_vertices_sum() const {
-    return m_cross_vertices_sum.load();
+    return m_vertex_data[1].m_sum.load();
 }
 
-GLuint Chunk::get_transparent_vbo() const { return m_transparent_normal_vbo; }
-size_t Chunk::get_transparent_vertices_sum() const {
-    return m_transparent_vertices_sum.load();
+GLuint Chunk::get_normal_discard_vao() const { return m_vertex_data[2].m_vao; }
+size_t Chunk::get_normal_discard_vertices_sum() const {
+    return m_vertex_data[2].m_sum.load();
+}
+
+GLuint Chunk::get_normal_blend_vao() const { return m_vertex_data[3].m_vao; }
+size_t Chunk::get_normal_blend_vertices_sum() const {
+    return m_vertex_data[3].m_sum.load();
 }
 
 void Chunk::gen_phase_one() {
@@ -216,9 +198,8 @@ void Chunk::gen_phase_six(
         Logger::error("ChunkGenerator is Nullptr");
         return;
     }
+    // This must be fully completed before any other operations can proceed!
     m_generator->blend_surface_blocks_borders(neighbor_block);
-    m_generator->generate_cave();
-    m_generator->generate_river();
 }
 
 void Chunk::gen_phase_seven() {
@@ -226,6 +207,10 @@ void Chunk::gen_phase_seven() {
         Logger::error("ChunkGenerator is Nullptr");
         return;
     }
+    m_generator->ocean_build();
+    m_generator->generate_river();
+    m_generator->generate_cave();
+
     m_generator->generate_vegetation();
     mark_dirty();
     m_generator = nullptr;
@@ -235,33 +220,12 @@ void Chunk::upload_to_gpu() {
 
     ASSERT(is_need_upload());
 
-    if (m_normal_vbo == 0) {
-        glGenBuffers(1, &m_normal_vbo);
+    std::lock_guard lk(m_vertexs_data_mutex);
+
+    for (auto& data : m_vertex_data) {
+        data.upload();
     }
 
-    std::lock_guard lk(m_vertexs_data_mutex);
-    glBindBuffer(GL_ARRAY_BUFFER, m_normal_vbo);
-    glBufferData(GL_ARRAY_BUFFER, m_normal_vertices.size() * sizeof(Vertex),
-                 m_normal_vertices.data(), GL_DYNAMIC_DRAW);
-    glBindBuffer(GL_ARRAY_BUFFER, 0);
-    if (m_cross_plane_vertices.size() != 0) {
-        if (m_cross_plane_vbo == 0) {
-            glGenBuffers(1, &m_cross_plane_vbo);
-        }
-        glBindBuffer(GL_ARRAY_BUFFER, m_cross_plane_vbo);
-        glBufferData(GL_ARRAY_BUFFER,
-                     m_cross_plane_vertices.size() * sizeof(Vertex),
-                     m_cross_plane_vertices.data(), GL_DYNAMIC_DRAW);
-    }
-    if (m_transparent_normal_vertices.size() != 0) {
-        if (m_transparent_normal_vbo == 0) {
-            glGenBuffers(1, &m_transparent_normal_vbo);
-        }
-        glBindBuffer(GL_ARRAY_BUFFER, m_transparent_normal_vbo);
-        glBufferData(GL_ARRAY_BUFFER,
-                     m_transparent_normal_vertices.size() * sizeof(Vertex),
-                     m_transparent_normal_vertices.data(), GL_DYNAMIC_DRAW);
-    }
     // after fininshed it, can use
     clear_dirty();
     m_need_upload = false;
@@ -300,10 +264,7 @@ unsigned Chunk::seed() const {
 
 BiomeConditions& Chunk::conditions() { return m_conditions; }
 
-void Chunk::gen_normal_vertices(
-    const std::array<const std::vector<BlockType>*, 4>& neighbor_block) {
-    m_normal_vertices.clear();
-    m_transparent_normal_vertices.clear();
+void Chunk::gen_vertices(const OptionalBlockVectorArray& neighbor_block) {
     static const glm::ivec3 DIR[6] = {{0, 0, 1},  {1, 0, 0}, {0, 0, -1},
                                       {-1, 0, 0}, {0, 1, 0}, {0, -1, 0}};
 
@@ -336,8 +297,9 @@ void Chunk::gen_normal_vertices(
                             World::chunk_pos(world_nx, world_nz);
 
                         auto is_culled =
-                            [&](const std::vector<BlockType>* chunk_blocks) {
-                                if (chunk_blocks == nullptr) {
+                            [&](const std::optional<std::vector<BlockType>>&
+                                    chunk_blocks) {
+                                if (chunk_blocks == std::nullopt) {
                                     return true;
                                 }
                                 int x, y, z;
@@ -399,6 +361,10 @@ void Chunk::gen_normal_vertices(
                     if (neighbor_culled) {
                         continue;
                     }
+                    if (BlockManager::is_cross_plane(cur_id)) {
+                        gen_cross_plane_vertices(world_x, world_y, world_z,
+                                                 cur_id);
+                    }
                     for (int i = 0; i < 6; i++) {
                         Vertex vex = {
                             VERTICES_POS[face][i][0] + (float)world_x * 1.0f,
@@ -410,55 +376,57 @@ void Chunk::gen_normal_vertices(
 
                         };
                         if (BlockManager::is_transparent(cur_id)) {
-                            m_transparent_normal_vertices.emplace_back(vex);
+                            if (BlockManager::is_discard(cur_id) &&
+                                BlockManager::is_blend(cur_id)) {
+                                Logger::warn(
+                                    "Block id {} is both discard and blend is "
+                                    "must only one can true !!!",
+                                    cur_id);
+                            }
+                            if (BlockManager::is_discard(cur_id)) {
+                                m_vertex_data[2].m_vertices.emplace_back(vex);
+                            } else if (BlockManager::is_blend(cur_id)) {
+                                m_vertex_data[3].m_vertices.emplace_back(vex);
+                            } else {
+                                Logger::warn("Id {} is transparent but not "
+                                             "discard or blend",
+                                             cur_id);
+                                m_vertex_data[3].m_vertices.emplace_back(vex);
+                            }
+
                         } else {
-                            m_normal_vertices.emplace_back(vex);
+                            m_vertex_data[0].m_vertices.emplace_back(vex);
                         }
                     }
                 }
             }
         }
     }
-    m_normal_vertices_sum = m_normal_vertices.size();
-    m_transparent_vertices_sum = m_transparent_normal_vertices.size();
 }
-void Chunk::gen_cross_plane_vertices() {
+void Chunk::gen_cross_plane_vertices(int world_x, int world_y, int world_z,
+                                     BlockType id) {
 
-    m_cross_plane_vertices.clear();
+    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++) {
+            Vertex 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))
 
-    for (int x = 0; x < SIZE_X; x++) {
-        for (int y = 0; y < SIZE_Y; y++) {
-            for (int z = 0; z < SIZE_Z; z++) {
-                int world_x = x + m_chunk_pos.x * CHUNK_SIZE;
-                int world_z = z + m_chunk_pos.z * CHUNK_SIZE;
-                int world_y = y;
-                int id = m_blocks[index(x, y, z)];
-
-                if (!BlockManager::is_cross_plane(id)) {
-                    continue;
-                }
-                for (int face = 0; face < 2; face++) {
-                    for (int i = 0; i < 6; i++) {
-                        Vertex 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))
-
-                        };
-                        m_cross_plane_vertices.emplace_back(vex);
-                    }
-                }
-            }
+            };
+            m_vertex_data[1].m_vertices.emplace_back(vex);
         }
     }
-    m_cross_vertices_sum = m_cross_plane_vertices.size();
-    // Logger::info("Cross Sum {}", m_cross_vertices_sum.load());
 }
 
+// Logger::info("Cross Sum {}", m_cross_vertices_sum.load());
+
 } // namespace Cubed

src/gameplay/chunk_generator.cpp

@@ -3,6 +3,7 @@
 #include "Cubed/gameplay/builders/desert_builder.hpp"
 #include "Cubed/gameplay/builders/forest_builder.hpp"
 #include "Cubed/gameplay/builders/mountain_builder.hpp"
+#include "Cubed/gameplay/builders/ocean_builder.hpp"
 #include "Cubed/gameplay/builders/plain_builder.hpp"
 #include "Cubed/gameplay/builders/river_builder.hpp"
 #include "Cubed/gameplay/builders/snowy_plain_builder.hpp"
@@ -17,11 +18,11 @@ namespace Cubed {
 
 using enum BiomeType;
 
-constexpr int BLEND_RADIUS = 12;
+constexpr int BLEND_RADIUS = 8;
 ChunkGenerator::ChunkGenerator(Chunk& chunk) : m_chunk(chunk) {
     ASSERT_MSG(is_init, "ChunksGenerator is not init");
     ChunkPos pos = m_chunk.get_chunk_pos();
-    unsigned seed = HASH::mix_hash(pos.x, pos.z, m_generator_seed);
+    unsigned seed = HASH::chunk_seed_hash(pos.x, pos.z, m_generator_seed);
     m_random.init(seed);
     m_chunk_seed = seed;
 }
@@ -166,18 +167,43 @@ void ChunkGenerator::generate_heightmap() {
             amplitude = std::lerp(10, 40, t);
             */
             float t;
-            if (mountainous >= 0.7f) {
-                t = Math::smootherstep(0.7f, 0.75, mountainous);
-                base_y = std::lerp(70, 88, t);
-                amplitude = std::lerp(28, 48, t);
-            } else if (mountainous >= 0.65f) {
-                t = Math::smootherstep(0.65f, 0.7f, mountainous);
-                base_y = std::lerp(66, 70, t);
+            if (mountainous >= 0.95f) {
+                t = Math::smootherstep(0.95f, 1.0f, mountainous);
+                base_y = std::lerp(130, 140, t);
+                amplitude = std::lerp(38, 48, t);
+            } else if (mountainous >= 0.85f) {
+                t = Math::smootherstep(0.85f, 0.95f, mountainous);
+                base_y = std::lerp(100, 130, t);
+                amplitude = std::lerp(28, 38, t);
+            } else if (mountainous >= 0.8) {
+                t = Math::smootherstep(0.8f, 0.85f, mountainous);
+                base_y = std::lerp(85, 100, t);
                 amplitude = std::lerp(18, 28, t);
+            } else if (mountainous >= 0.75f) {
+                t = Math::smootherstep(0.75f, 0.8f, mountainous);
+                base_y = std::lerp(70, 85, t);
+                amplitude = std::lerp(6, 18, t);
+            } else if (mountainous >= 0.7) {
+                t = Math::smootherstep(0.7f, 0.75f, mountainous);
+                base_y = std::lerp(66, 70, t);
+                amplitude = std::lerp(6, 6, t);
+
+            } else if (mountainous >= 0.45f) {
+                t = Math::smootherstep(0.45f, 0.7f, mountainous);
+                base_y = std::lerp(64, 66, t);
+                amplitude = std::lerp(6, 6, t);
+            } else if (mountainous >= 0.3f) {
+                t = Math::smootherstep(0.3f, 0.45f, mountainous);
+                base_y = std::lerp(60, 64, t);
+                amplitude = std::lerp(6, 6, t);
+            } else if (mountainous >= 0.25f) {
+                t = Math::smootherstep(0.25f, 0.3f, mountainous);
+                base_y = std::lerp(44, 60, t);
+                amplitude = std::lerp(6, 6, t);
             } else {
-                t = Math::smootherstep(0.55, 0.65, mountainous);
-                base_y = std::lerp(58, 66, t);
-                amplitude = std::lerp(8, 18, t);
+                t = Math::smootherstep(0.0f, 0.25f, mountainous);
+                base_y = std::lerp(35, 44, t);
+                amplitude = std::lerp(3, 6, t);
             }
             heightmap[x][z] =
                 base_y + fbm_height(world_x, world_z, octaves, lacunarity, gain,
@@ -451,9 +477,11 @@ void ChunkGenerator::blend_surface_blocks_borders(
         for (int y = WORLD_HEIGHT - 1; y >= 0; --y) {
             int idx = Chunk::index(nx, y,
                                    nz); // linear index: y * area + z * size + x
-            if (idx >= 0 && idx < static_cast<int>(blocks.size()) &&
-                blocks[idx] != 0) {
-                return blocks[idx];
+            if (idx >= 0 && idx < static_cast<int>(blocks.size())) {
+                BlockType neighbor_type = blocks[idx];
+                if (BlockManager::is_transitional(neighbor_type)) {
+                    return neighbor_type;
+                }
             }
         }
         return 0; // fallback, should not happen for valid chunks
@@ -473,8 +501,8 @@ void ChunkGenerator::blend_surface_blocks_borders(
 
             // Weight map: type -> total weight
             std::unordered_map<BlockType, float> weights;
-            weights[type_self] = 1.0f; // self weight
-
+            float self_weight = 1.0f;
+            weights[type_self] = self_weight;
             // --- Right neighbor (index 0) ---
             if (neighbor_block[0] && x >= CHUNK_SIZE - BLEND_RADIUS) {
                 int dist = (CHUNK_SIZE - 1) - x;
@@ -523,47 +551,50 @@ void ChunkGenerator::blend_surface_blocks_borders(
                 }
             }
 
+            if (weights.empty()) {
+                continue;
+            }
             // Find type with maximum total weight
             BlockType final_type = type_self;
-            float max_weight = weights[type_self];
+            /*float max_weight = weights[type_self];
             for (const auto& [type, w] : weights) {
                 if (w > max_weight) {
                     max_weight = w;
                     final_type = type;
                 }
+            }*/
+
+            float sum = 0.0f;
+            for (auto& kv : weights) {
+                sum += kv.second;
+            }
+            float rnd = m_random.random_float(0.0f, 1.0f);
+            float accum = 0.0f;
+            for (auto [t, w] : weights) {
+                accum += w / sum;
+                if (rnd < accum) {
+                    final_type = t;
+                    break;
+                }
             }
 
-            if (final_type == 0) {
-                return;
+            if (!BlockManager::is_transitional(final_type)) {
+                continue;
             }
-
             // Update the top block if the type changed
             if (final_type != type_self) {
                 // top block
-                if (final_type == 7 && top_y > SEA_LEVEL) {
-                    if (type_self == 7) {
-                        m_blocks[Chunk::index(x, top_y, z)] = 0;
-                    } else {
-                        m_blocks[Chunk::index(x, top_y, z)] = type_self;
-                    }
-
-                } else {
-                    m_blocks[Chunk::index(x, top_y, z)] = final_type;
-                }
-
+                BlockType new_surface = final_type;
+                m_blocks[Chunk::index(x, top_y, z)] = new_surface;
                 // bottom block
                 unsigned fill_type = 2;
-                if (final_type == 1) {
+                if (final_type == 1 || final_type == 8) {
                     fill_type = 2;
-                } else if (final_type == 4) {
-                    fill_type = 4;
+                } else {
+                    fill_type = final_type;
                 }
-                for (int y = top_y - 5; y < top_y; y++) {
-                    if (fill_type == 7 && y > SEA_LEVEL) {
-                        m_blocks[Chunk::index(x, y, z)] = 0;
-                    } else {
-                        m_blocks[Chunk::index(x, y, z)] = fill_type;
-                    }
+                for (int y = std::max(0, top_y - 5); y < top_y; y++) {
+                    m_blocks[Chunk::index(x, y, z)] = fill_type;
                 }
             }
         }
@@ -600,63 +631,109 @@ void ChunkGenerator::make_biome_builder() {
     case SNOWY_PLAIN:
         m_biome_builder = std::make_unique<SnowyPlainBuilder>(*this);
         break;
+    case OCEAN:
+        m_biome_builder = std::make_unique<OceanBuilder>(*this);
+        break;
     case NONE:
         m_biome_builder = nullptr;
         break;
     }
 }
 
+void ChunkGenerator::ocean_build() { m_biome_builder->ocean_water_build(); }
+
+void ChunkGenerator::carve_worm(
+    const std::vector<PathPoint>& points, const ChunkPos& chunk_pos,
+    std::function<void(int /*x*/, int /*y*/, int /*z*/)> on_hit) {
+    const int CHUNK_MIN_X = chunk_pos.x * CHUNK_SIZE;
+    const int CHUNK_MIN_Z = chunk_pos.z * CHUNK_SIZE;
+    const int CHUNK_MAX_X = CHUNK_MIN_X + SIZE_X - 1;
+    const int CHUNK_MAX_Z = CHUNK_MIN_Z + SIZE_Z - 1;
+    const int CHUNK_MIN_Y = 0;
+    const int CHUNK_MAX_Y = SIZE_Y - 1;
+    for (const auto& point : points) {
+
+        const glm::vec3& center = point.pos;
+        float rad_xz = point.rad_xz;
+        float rad_y = point.rad_y;
+
+        if (center.x + rad_xz < CHUNK_MIN_X ||
+            center.x - rad_xz > CHUNK_MAX_X ||
+            center.z + rad_xz < CHUNK_MIN_Z ||
+            center.z - rad_xz > CHUNK_MAX_Z || center.y + rad_y < CHUNK_MIN_Y ||
+            center.y - rad_y > CHUNK_MAX_Y) {
+            continue;
+        }
+
+        int min_x = static_cast<int>(std::floor(center.x - rad_xz));
+        int max_x = static_cast<int>(std::floor(center.x + rad_xz));
+        int min_z = static_cast<int>(std::floor(center.z - rad_xz));
+        int max_z = static_cast<int>(std::floor(center.z + rad_xz));
+        int min_y = static_cast<int>(std::floor(center.y - rad_y));
+        int max_y = static_cast<int>(std::floor(center.y + rad_y));
+
+        min_x = std::max(min_x, CHUNK_MIN_X);
+        max_x = std::min(max_x, CHUNK_MAX_X);
+        min_z = std::max(min_z, CHUNK_MIN_Z);
+        max_z = std::min(max_z, CHUNK_MAX_Z);
+        min_y = std::max(min_y, CHUNK_MIN_Y);
+        max_y = std::min(max_y, CHUNK_MAX_Y);
+
+        glm::vec3 right_raw =
+            glm::cross(point.tangent, glm::vec3(0.0f, 1.0f, 0.0f));
+        if (glm::dot(right_raw, right_raw) < 1e-6f)
+            right_raw = glm::cross(point.tangent, glm::vec3(1.0f, 0.0f, 0.0f));
+        glm::vec3 right = glm::normalize(right_raw);
+        glm::vec3 up = glm::normalize(glm::cross(point.tangent, right));
+
+        float inv_a2 = 1.0f / (point.rad_xz * point.rad_xz);
+        float inv_b2 = 1.0f / (point.rad_y * point.rad_y);
+
+        for (int wy = min_y; wy <= max_y; ++wy) {
+            if (wy == 0)
+                continue;
+            float dy = static_cast<float>(wy) - point.pos.y;
+
+            float vy_contrib = dy * up.y;
+            float vy2 = vy_contrib * vy_contrib * inv_b2;
+            if (vy2 >= 1.0f)
+                continue;
+
+            for (int wx = min_x; wx <= max_x; ++wx) {
+                float dx = static_cast<float>(wx) - point.pos.x;
+                for (int wz = min_z; wz <= max_z; ++wz) {
+                    float dz = static_cast<float>(wz) - point.pos.z;
+                    glm::vec3 to_point(dx, dy, dz);
+
+                    float h = glm::dot(to_point, right);
+                    float v = glm::dot(to_point, up);
+
+                    if (h * h * inv_a2 + v * v * inv_b2 > 1.0f)
+                        continue;
+                    int x = wx - CHUNK_MIN_X;
+                    on_hit(x, wy, wz - CHUNK_MIN_Z);
+                }
+            }
+        }
+    }
+}
+
 void ChunkGenerator::generate_cave() {
     auto& cave_carver = m_chunk.world().cave_carcer();
     auto& paths = cave_carver.paths();
     const auto& chunk_pos = m_chunk.chunk_pos();
     auto& blocks = m_chunk.blocks();
-    const int CHUNK_MIN_X = chunk_pos.x * CHUNK_SIZE;
-    const int CHUNK_MIN_Z = chunk_pos.z * CHUNK_SIZE;
-    const int CHUNK_MAX_X = CHUNK_MIN_X + SIZE_X - 1;
-    const int CHUNK_MAX_Z = CHUNK_MIN_Z + SIZE_Z - 1;
-    const int CHUNK_MIN_Y = 0;
-    const int CHUNK_MAX_Y = SIZE_Y - 1;
+
     for (auto& [id, path] : paths) {
-        for (const auto& point : path.points()) {
 
-            const glm::vec3& center = point.pos;
-            float rad_xz = point.rad_xz;
-            float rad_y = point.rad_y;
-
-            int min_x = static_cast<int>(std::floor(center.x - rad_xz));
-            int max_x = static_cast<int>(std::floor(center.x + rad_xz));
-            int min_z = static_cast<int>(std::floor(center.z - rad_xz));
-            int max_z = static_cast<int>(std::floor(center.z + rad_xz));
-            int min_y = static_cast<int>(std::floor(center.y - rad_y));
-            int max_y = static_cast<int>(std::floor(center.y + rad_y));
-
-            min_x = std::max(min_x, CHUNK_MIN_X);
-            max_x = std::min(max_x, CHUNK_MAX_X);
-            min_z = std::max(min_z, CHUNK_MIN_Z);
-            max_z = std::min(max_z, CHUNK_MAX_Z);
-            min_y = std::max(min_y, CHUNK_MIN_Y);
-            max_y = std::min(max_y, CHUNK_MAX_Y);
-
-            for (int wx = min_x; wx <= max_x; ++wx) {
-                int x = wx - CHUNK_MIN_X;
-                for (int wz = min_z; wz <= max_z; ++wz) {
-                    int z = wz - CHUNK_MIN_Z;
-                    for (int wy = min_y; wy <= max_y; ++wy) {
-                        int y = wy;
-                        glm::vec3 pos(static_cast<float>(wx),
-                                      static_cast<float>(wy),
-                                      static_cast<float>(wz));
-                        if (point.contains(pos)) {
-                            if (y == 0) {
-                                continue;
-                            }
-                            blocks[Chunk::index(x, y, z)] = 0;
-                        }
-                    }
-                }
-            }
-        }
+        carve_worm(path.points(), chunk_pos, [&](int x, int y, int z) -> void {
+            int idx = Chunk::index(x, y, z);
+            if (blocks[idx] == 7)
+                return;
+            if (y < WORLD_SIZE_Y - 1 && blocks[Chunk::index(x, y + 1, z)] == 7)
+                return;
+            blocks[idx] = 0;
+        });
         path.clear_chunk(chunk_pos);
     }
 }
@@ -667,63 +744,27 @@ void ChunkGenerator::generate_river() {
     auto& paths = river_worm.paths();
     const auto& chunk_pos = m_chunk.chunk_pos();
     auto& blocks = m_chunk.blocks();
-    const int CHUNK_MIN_X = chunk_pos.x * CHUNK_SIZE;
-    const int CHUNK_MIN_Z = chunk_pos.z * CHUNK_SIZE;
-    const int CHUNK_MAX_X = CHUNK_MIN_X + SIZE_X - 1;
-    const int CHUNK_MAX_Z = CHUNK_MIN_Z + SIZE_Z - 1;
-    const int CHUNK_MIN_Y = 0;
-    const int CHUNK_MAX_Y = SIZE_Y - 1;
 
     bool is_river = false;
 
     for (auto& [id, path] : paths) {
-        for (const auto& point : path.points()) {
-            if (m_chunk.biome() == BiomeType::DESERT) {
-                path.clear_chunk(chunk_pos);
-                continue;
-            }
-            const glm::vec3& center = point.pos;
-            float rad_xz = point.rad_xz;
-            float rad_y = point.rad_y;
-
-            int min_x = static_cast<int>(std::floor(center.x - rad_xz));
-            int max_x = static_cast<int>(std::floor(center.x + rad_xz));
-            int min_z = static_cast<int>(std::floor(center.z - rad_xz));
-            int max_z = static_cast<int>(std::floor(center.z + rad_xz));
-            int min_y = static_cast<int>(std::floor(center.y - rad_y));
-            int max_y = static_cast<int>(std::floor(center.y + rad_y));
-
-            min_x = std::max(min_x, CHUNK_MIN_X);
-            max_x = std::min(max_x, CHUNK_MAX_X);
-            min_z = std::max(min_z, CHUNK_MIN_Z);
-            max_z = std::min(max_z, CHUNK_MAX_Z);
-            min_y = std::max(min_y, CHUNK_MIN_Y);
-            max_y = std::min(max_y, CHUNK_MAX_Y);
-
-            for (int wx = min_x; wx <= max_x; ++wx) {
-                int x = wx - CHUNK_MIN_X;
-                for (int wz = min_z; wz <= max_z; ++wz) {
-                    int z = wz - CHUNK_MIN_Z;
-                    for (int wy = min_y; wy <= max_y; ++wy) {
-                        int y = wy;
-                        glm::vec3 pos(static_cast<float>(wx),
-                                      static_cast<float>(wy),
-                                      static_cast<float>(wz));
-                        if (point.contains(pos)) {
-                            if (y > SEA_LEVEL) {
-                                blocks[Chunk::index(x, y, z)] = 0;
-                                continue;
-                            }
-                            is_river = true;
-                            if (blocks[Chunk::index(x, y, z)] == 0) {
-                                continue;
-                            }
-                            blocks[Chunk::index(x, y, z)] = 7;
-                        }
-                    }
-                }
-            }
+        if ((m_chunk.biome() == BiomeType::DESERT) ||
+            (m_chunk.biome() == BiomeType::OCEAN)) {
+            path.clear_chunk(chunk_pos);
+            continue;
         }
+        carve_worm(path.points(), chunk_pos, [&](int x, int y, int z) -> void {
+            int idx = Chunk::index(x, y, z);
+            if (y > SEA_LEVEL) {
+                blocks[idx] = 0;
+                return;
+            }
+            is_river = true;
+            if (blocks[idx] == 0) {
+                return;
+            }
+            blocks[idx] = 7;
+        });
         path.clear_chunk(chunk_pos);
     }
     if (is_river) {

src/gameplay/river_path.cpp

@@ -5,12 +5,15 @@
 
 #include <algorithm>
 namespace Cubed {
-RiverPath::RiverPath(unsigned int world_seed, int path_id,
+RiverPath::RiverPath(unsigned int chunk_seed, unsigned world_seed,
                      const glm::vec3& start_pos) {
-    m_path_id = path_id;
-    m_seed = HASH::combine_32(world_seed, path_id);
+
+    m_seed = HASH::combine_32(chunk_seed, world_seed);
     m_random.init(m_seed);
+
     m_yaw = m_random.random_float(0.0f, 360.0f);
+
+    m_initial_yaw = m_yaw;
     m_pitch = 0.0f;
     m_start_path_point.pos = start_pos;
     m_start_path_point.rad_xz =
@@ -41,14 +44,15 @@ void RiverPath::collect_path_points() {
 
         float t = Math::smootherstep(0, m_step - 1, i);
 
-        float drad_xz = m_start_path_point.rad_xz * (1.0f - t);
-        float drad_y = m_start_path_point.rad_y * (1.0f - t);
+        float drad_xz = m_start_path_point.rad_xz * t;
+        float drad_y = m_start_path_point.rad_y * t;
         drad_xz = std::max(drad_xz, 4.0f);
         drad_y = std::max(drad_y, 4.0f);
         m_points.emplace_back(m_points[i].pos + glm::vec3{dx, dy, dz}, drad_xz,
                               drad_y);
 
         m_yaw += m_random.random_float(m_delta_angle_min, m_delta_angle_max);
+        m_yaw = std::clamp(m_yaw, m_initial_yaw - 10.0f, m_initial_yaw + 10.0f);
     }
     auto n = m_points.size();
     if (n >= 2) {
@@ -72,7 +76,8 @@ void RiverPath::precompute_chunk_coverage() {
 
         for (int cx = min_cx; cx <= max_cx; ++cx)
             for (int cz = min_cz; cz <= max_cz; ++cz)
-                m_pending_chunks.insert({cx, cz});
+                m_pending_chunks.insert(
+                    std::make_pair(ChunkPos{cx, cz}, false));
     }
 }
 

src/gameplay/river_worm.cpp

@@ -5,11 +5,11 @@
 namespace Cubed {
 RiverWorm::RiverWorm() {}
 
-std::unordered_map<unsigned, RiverPath>& RiverWorm::paths() { return m_paths; }
+RiverWorm::RiverHashMap& RiverWorm::paths() { return m_paths; }
 
 void RiverWorm::init(unsigned world_seed) {
     m_seed = world_seed;
-    m_sum = 0;
+
     m_random.init(m_seed);
 }
 
@@ -20,15 +20,16 @@ void RiverWorm::reload(unsigned world_seed) {
 }
 
 void RiverWorm::add_path(const glm::vec3& pos, unsigned chunk_seed) {
-    m_paths.emplace(chunk_seed, RiverPath{m_seed, m_sum, pos});
-    m_sum++;
+    m_paths.emplace(chunk_seed, RiverPath{chunk_seed, m_seed, pos});
 }
 
 void RiverWorm::try_to_add_path(const ChunkPos& chunk_pos,
                                 unsigned chunk_seed) {
-    auto it = m_paths.find(chunk_seed);
-    if (it != m_paths.end()) {
-        return;
+    {
+        RiverHashMap::const_accessor acc;
+        if (m_paths.find(acc, chunk_seed)) {
+            return;
+        }
     }
     Random random{chunk_seed};
     if (random.random_bool(static_cast<double>(m_probability))) {
@@ -44,10 +45,17 @@ void RiverWorm::try_to_add_path(const ChunkPos& chunk_pos,
 }
 
 void RiverWorm::cleanup_finished_rivers() {
-    std::erase_if(m_paths,
-                  [](const auto& kv) { return kv.second.is_finished(); });
+    std::vector<unsigned> finished_keys;
+    for (const auto& pair : m_paths) {
+        if (pair.second.is_finished()) {
+            finished_keys.push_back(pair.first);
+        }
+    }
+    for (const auto& key : finished_keys) {
+        m_paths.erase(key);
+    }
 }
 
-int RiverWorm::river_sum() const { return m_sum; }
+int RiverWorm::river_sum() const { return m_paths.size(); }
 float& RiverWorm::river_probability() { return m_probability; }
 } // namespace Cubed

src/gameplay/tree.cpp

@@ -1,7 +1,6 @@
 #include "Cubed/gameplay/tree.hpp"
 
 #include "Cubed/gameplay/chunk.hpp"
-#include "Cubed/tools/log.hpp"
 
 #include <array>
 
@@ -32,7 +31,6 @@ bool build_tree(Chunk& chunk, const glm::ivec3& pos) {
     auto& block = chunk.get_chunk_blocks();
 
     if (block[Chunk::index(pos)] != 1) {
-        Logger::info("Root is not Grass Block");
         return false;
     }
     for (const auto& d : TREE) {

src/gameplay/vertex_data.cpp

@@ -0,0 +1,61 @@
+#include "Cubed/gameplay/vertex_data.hpp"
+
+#include "Cubed/gameplay/world.hpp"
+
+namespace Cubed {
+VertexData::VertexData(World& world) : m_world(world) {}
+VertexData::~VertexData() {
+    if (m_vbo != 0) {
+        m_world.push_delete_vbo(m_vbo);
+    }
+    if (m_vao != 0) {
+        m_world.push_delete_vao(m_vao);
+    }
+}
+VertexData::VertexData(VertexData&& o) noexcept
+    : m_vertices(std::move(o.m_vertices)), m_vbo(o.m_vbo), m_vao(o.m_vao),
+      m_sum(o.m_sum.load()), m_world(o.m_world) {
+    o.m_vbo = 0;
+    o.m_sum = 0;
+    o.m_vao = 0;
+}
+VertexData& VertexData::operator=(VertexData&& o) noexcept {
+    m_vbo = o.m_vbo;
+    o.m_vbo = 0;
+    m_sum = o.m_sum.load();
+    o.m_sum = 0;
+    m_vertices = std::move(o.m_vertices);
+    m_vao = o.m_vao;
+    o.m_vao = 0;
+    return *this;
+}
+void VertexData::upload() {
+    if (m_vertices.size() == 0) {
+        return;
+    }
+    if (m_vao == 0) {
+        glGenVertexArrays(1, &m_vao);
+    }
+    if (m_vbo == 0) {
+        glGenBuffers(1, &m_vbo);
+    }
+    glBindVertexArray(m_vao);
+    glBindBuffer(GL_ARRAY_BUFFER, m_vbo);
+    glBufferData(GL_ARRAY_BUFFER, m_vertices.size() * sizeof(Vertex),
+                 m_vertices.data(), GL_DYNAMIC_DRAW);
+
+    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, sizeof(Vertex), (void*)0);
+    glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, sizeof(Vertex),
+                          (void*)offsetof(Vertex, s));
+    glVertexAttribPointer(2, 1, GL_FLOAT, GL_FALSE, sizeof(Vertex),
+                          (void*)offsetof(Vertex, layer));
+
+    glEnableVertexAttribArray(0);
+    glEnableVertexAttribArray(1);
+    glEnableVertexAttribArray(2);
+
+    glBindVertexArray(0);
+    glBindBuffer(GL_ARRAY_BUFFER, 0);
+}
+void VertexData::update_sum() { m_sum = m_vertices.size(); }
+} // namespace Cubed

src/gameplay/world.cpp

@@ -1,12 +1,11 @@
 #include "Cubed/gameplay/world.hpp"
 
 #include "Cubed/config.hpp"
-#include "Cubed/debug_collector.hpp"
 #include "Cubed/gameplay/player.hpp"
-#include "Cubed/texture_manager.hpp"
 #include "Cubed/tools/cubed_assert.hpp"
 #include "Cubed/tools/cubed_hash.hpp"
-#include "Cubed/tools/math_tools.hpp"
+
+#include <execution>
 
 namespace Cubed {
 
@@ -27,6 +26,13 @@ World::~World() {
         }
         m_pending_delete_vbo.clear();
     }
+    {
+        std::lock_guard lk(m_delete_vao_mutex);
+        for (auto x : m_pending_delete_vao) {
+            glDeleteVertexArrays(1, &x);
+        }
+        m_pending_delete_vao.clear();
+    }
 }
 
 bool World::can_move(const AABB& player_box) const { return true; }
@@ -85,6 +91,7 @@ void World::init_world() {
 void World::init_chunks() {
     hot_reload();
     while (!m_chunk_gen_finished) {
+        // Logger::info("World Spawn: {:.2f}%", m_chunk_gen_fraction.load());
         std::this_thread::sleep_for(std::chrono::microseconds(200));
     }
 }
@@ -291,115 +298,6 @@ void World::init_chunks() {
     }
 }
 */
-void World::render(const glm::mat4& mvp_matrix,
-                   const TextureManager& texture_manager,
-                   const glm::vec3& camera_pos) {
-    Math::extract_frustum_planes(mvp_matrix, m_planes);
-    int rendered_sum = 0;
-    for (const auto& snapshot : m_render_snapshots) {
-
-        if (is_aabb_in_frustum(snapshot.center, snapshot.half_extents)) {
-            glBindTexture(GL_TEXTURE_2D_ARRAY,
-                          texture_manager.get_texture_array());
-            glBindBuffer(GL_ARRAY_BUFFER, snapshot.normal_vbo);
-            glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, sizeof(Vertex),
-                                  (void*)0);
-            glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, sizeof(Vertex),
-                                  (void*)offsetof(Vertex, s));
-            glVertexAttribPointer(2, 1, GL_FLOAT, GL_FALSE, sizeof(Vertex),
-                                  (void*)offsetof(Vertex, layer));
-
-            glEnableVertexAttribArray(0);
-            glEnableVertexAttribArray(1);
-            glEnableVertexAttribArray(2);
-
-            glDrawArrays(GL_TRIANGLES, 0, snapshot.normal_vertices_count);
-            glBindBuffer(GL_ARRAY_BUFFER, 0);
-
-            rendered_sum++;
-        }
-    }
-    glDepthMask(GL_FALSE);
-
-    struct SortableSnapshot {
-        const ChunkRenderSnapshot* snapshot;
-        float distance;
-    };
-
-    std::vector<SortableSnapshot> cross_list;
-    std::vector<SortableSnapshot> transparent_list;
-
-    for (const auto& snapshot : m_render_snapshots) {
-
-        if (!is_aabb_in_frustum(snapshot.center, snapshot.half_extents)) {
-            continue;
-        }
-
-        float dist = glm::distance(camera_pos, snapshot.center);
-        glm::vec2 camera_pos_xz{camera_pos.x, camera_pos.z};
-        if (snapshot.cross_vertices_count != 0) {
-            glm::vec2 center_xz{snapshot.center.x, snapshot.center.z};
-            float dist2d = glm::distance(camera_pos_xz, center_xz);
-            if (dist2d <= CROSS_PLANE_DISTANCE * 16) {
-                cross_list.push_back({&snapshot, dist});
-            }
-        }
-        if (snapshot.transparent_vertices_count != 0) {
-            transparent_list.push_back({&snapshot, dist});
-        }
-    }
-    std::sort(transparent_list.begin(), transparent_list.end(),
-              [](const SortableSnapshot& a, const SortableSnapshot& b) {
-                  return a.distance > b.distance;
-              });
-    std::sort(cross_list.begin(), cross_list.end(),
-              [](const SortableSnapshot& a, const SortableSnapshot& b) {
-                  return a.distance > b.distance;
-              });
-
-    for (const auto& item : cross_list) {
-        const auto& snapshot = *item.snapshot;
-        glBindTexture(GL_TEXTURE_2D_ARRAY,
-                      texture_manager.get_cross_plane_array());
-        glBindBuffer(GL_ARRAY_BUFFER, snapshot.cross_vbo);
-        glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, sizeof(Vertex),
-                              (void*)0);
-        glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, sizeof(Vertex),
-                              (void*)offsetof(Vertex, s));
-        glVertexAttribPointer(2, 1, GL_FLOAT, GL_FALSE, sizeof(Vertex),
-                              (void*)offsetof(Vertex, layer));
-
-        glEnableVertexAttribArray(0);
-        glEnableVertexAttribArray(1);
-        glEnableVertexAttribArray(2);
-
-        glDrawArrays(GL_TRIANGLES, 0, snapshot.cross_vertices_count);
-        glBindBuffer(GL_ARRAY_BUFFER, 0);
-    }
-
-    for (const auto& item : transparent_list) {
-        const auto& snapshot = *item.snapshot;
-        glBindTexture(GL_TEXTURE_2D_ARRAY, texture_manager.get_texture_array());
-        glBindBuffer(GL_ARRAY_BUFFER, snapshot.transparent_vbo);
-        glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, sizeof(Vertex),
-                              (void*)0);
-        glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, sizeof(Vertex),
-                              (void*)offsetof(Vertex, s));
-        glVertexAttribPointer(2, 1, GL_FLOAT, GL_FALSE, sizeof(Vertex),
-                              (void*)offsetof(Vertex, layer));
-
-        glEnableVertexAttribArray(0);
-        glEnableVertexAttribArray(1);
-        glEnableVertexAttribArray(2);
-
-        glDrawArrays(GL_TRIANGLES, 0, snapshot.transparent_vertices_count);
-        glBindBuffer(GL_ARRAY_BUFFER, 0);
-    }
-
-    glDepthMask(GL_TRUE);
-    DebugCollector::get().report(
-        "rendered_chunk", "Rendered Chunk: " + std::to_string(rendered_sum));
-}
 
 ChunkPos World::chunk_pos(int world_x, int world_z) {
     int chunk_x, chunk_z;
@@ -424,8 +322,10 @@ void World::gen_chunks_internal() {
     m_chunk_gen_fraction = 0.0f;
     m_chunk_gen_finished = false;
     ChunkPosSet required_chunks;
-    ChunkHashMap temp_neighbor;
-    compute_required_chunks(required_chunks, temp_neighbor);
+    ChunkPairVector temp_neighbor;
+    std::vector<ChunkPos> need_gen_temp_chunks_pos;
+    compute_required_chunks(required_chunks, temp_neighbor,
+                            need_gen_temp_chunks_pos);
 
     ASSERT_MSG(!required_chunks.empty(), "required chunks is empty!!");
 
@@ -443,11 +343,14 @@ void World::gen_chunks_internal() {
 
     m_chunk_gen_fraction = 0.1f;
 
-    ChunkUpdateList new_chunks;
+    ChunkPairVector new_chunks;
+    ChunkHashMap new_temp_chunks;
     for (auto& pos : need_gen_chunks_pos) {
         new_chunks.push_back({pos, Chunk(*this, pos)});
     }
-
+    for (auto& pos : need_gen_temp_chunks_pos) {
+        new_temp_chunks.emplace(pos, Chunk(*this, pos));
+    }
     ConstChunkMap new_chunks_neighbor;
     //  affected neighbor
     ChunkPtrUpdateList affected_neighbor;
@@ -457,17 +360,28 @@ void World::gen_chunks_internal() {
 
     //  build new chunk, but the neighbor in m_chunks also need to re-build
 
-    for (auto& [pos, chunk] : new_chunks) {
-        chunk.gen_phase_one();
-        m_cave_carcer.try_to_add_path(pos, chunk.seed());
-        m_river_worm.try_to_add_path(pos, chunk.seed());
-    }
+    std::for_each(std::execution::par, new_chunks.begin(), new_chunks.end(),
+                  [this](std::pair<ChunkPos, Chunk>& new_chunk) {
+                      auto& [pos, chunk] = new_chunk;
+                      chunk.gen_phase_one();
+                      m_cave_carcer.try_to_add_path(pos, chunk.seed());
+                      m_river_worm.try_to_add_path(pos, chunk.seed());
+                  });
+
+    std::for_each(new_temp_chunks.begin(), new_temp_chunks.end(),
+                  [](std::pair<const ChunkPos, Chunk>& new_chunk) {
+                      auto& [pos, chunk] = new_chunk;
+                      chunk.gen_phase_one();
+                  });
     // precompute path to ensure the continuity of the path
-    for (auto& [pos, chunk] : temp_neighbor) {
-        chunk.gen_phase_one();
-        m_cave_carcer.try_to_add_path(pos, chunk.seed());
-        m_river_worm.try_to_add_path(pos, chunk.seed());
-    }
+    std::for_each(std::execution::par, temp_neighbor.begin(),
+                  temp_neighbor.end(),
+                  [this](std::pair<ChunkPos, Chunk>& new_chunk) {
+                      auto& [pos, chunk] = new_chunk;
+                      chunk.gen_phase_one();
+                      m_cave_carcer.try_to_add_path(pos, chunk.seed());
+                      m_river_worm.try_to_add_path(pos, chunk.seed());
+                  });
 
     m_chunk_gen_fraction = 0.2f;
 
@@ -505,15 +419,19 @@ void World::gen_chunks_internal() {
 
     m_chunk_gen_fraction = 0.3f;
 
-    for (auto& [pos, chunks] : new_chunks) {
-        chunks.gen_phase_three();
+    std::for_each(std::execution::par, new_chunks.begin(), new_chunks.end(),
+                  [](std::pair<ChunkPos, Chunk>& pair) {
+                      auto& [pos, chunks] = pair;
+                      chunks.gen_phase_three();
+                  });
+
+    for (auto& [pos, chunk] : new_temp_chunks) {
+        chunk.gen_phase_three();
     }
     // for (auto& [pos, chunks] : temp_neighbor) {
     //     chunks.gen_phase_three();
     // }
 
-    m_chunk_gen_fraction = 0.4f;
-
     /*
     for (int i = 0; i < 4; i++) {
         for (auto& [pos, chunks] : temp_neighbor) {
@@ -557,68 +475,106 @@ void World::gen_chunks_internal() {
         }
     }
     */
+    m_chunk_gen_fraction = 0.4f;
 
-    m_chunk_gen_fraction = 0.5f;
     for (auto& [pos, chunks] : new_chunks) {
         chunks.gen_phase_five();
     }
-
+    m_chunk_gen_fraction = 0.45f;
+    for (auto& [pos, chunk] : new_temp_chunks) {
+        chunk.gen_phase_five();
+    }
+    m_chunk_gen_fraction = 0.5f;
     /*
     for (auto& [pos, chunks] : temp_neighbor) {
         chunks.gen_phase_five();
     }
     */
 
-    std::array<std::optional<std::vector<BlockType>>, 4> neighbor_blocks_data;
-    for (auto& [pos, chunks] : new_chunks) {
+    std::vector<std::pair<Chunk*, OptionalBlockVectorArray>>
+        new_chunks_surface_blend_data(new_chunks.size());
+    for (size_t idx = 0; idx < new_chunks.size(); idx++) {
+        auto& [pos, chunk] = new_chunks[idx];
+        new_chunks_surface_blend_data[idx].first = &chunk;
         {
             // std::lock_guard lk(m_chunks_mutex);
             for (int i = 0; i < 4; i++) {
                 auto neighbor_pos = pos + CHUNK_DIR[i];
                 auto it = new_chunks_neighbor.find(neighbor_pos);
                 if (it == new_chunks_neighbor.end()) {
-                    neighbor_blocks_data[i] = std::nullopt;
+                    auto it = new_temp_chunks.find(neighbor_pos);
+                    if (it == new_temp_chunks.end()) {
+                        new_chunks_surface_blend_data[idx].second[i] =
+                            std::nullopt;
+                        Logger::warn(
+                            "Can't find neighbor for chunk surface blend");
+                        continue;
+                    }
+                    new_chunks_surface_blend_data[idx].second[i] =
+                        it->second.get_chunk_blocks();
                     continue;
                 }
-                neighbor_blocks_data[i] = it->second->get_chunk_blocks();
+                new_chunks_surface_blend_data[idx].second[i] =
+                    it->second->get_chunk_blocks();
             }
         }
-        chunks.gen_phase_six(neighbor_blocks_data);
     }
 
-    for (auto& [pos, chunks] : new_chunks) {
-        chunks.gen_phase_seven();
-    }
+    std::for_each(
+        std::execution::par, new_chunks_surface_blend_data.begin(),
+        new_chunks_surface_blend_data.end(),
+        [](std::pair<Chunk*, OptionalBlockVectorArray>& new_chunk_data) {
+            auto& [chunk, neighbor_data] = new_chunk_data;
+            chunk->gen_phase_six(neighbor_data);
+        });
+
+    m_chunk_gen_fraction = 0.55f;
+    std::for_each(std::execution::par, new_chunks.begin(), new_chunks.end(),
+                  [](std::pair<ChunkPos, Chunk>& new_chunk) {
+                      auto& [pos, chunk] = new_chunk;
+                      chunk.gen_phase_seven();
+                  });
 
     m_chunk_gen_fraction = 0.6f;
 
-    std::array<const std::vector<BlockType>*, 4> neighbor_block;
-    for (auto& [pos, chunk] : new_chunks) {
+    std::vector<std::pair<Chunk*, OptionalBlockVectorArray>>
+        new_chunk_vertices_data(new_chunks.size());
+    for (size_t idx = 0; idx < new_chunks.size(); idx++) {
+        auto& [pos, chunk] = new_chunks[idx];
+        new_chunk_vertices_data[idx].first = &chunk;
         for (int i = 0; i < 4; i++) {
             auto it = new_chunks_neighbor.find(pos + CHUNK_DIR[i]);
             if (it != new_chunks_neighbor.end()) {
-                neighbor_block[i] = &(it->second->get_chunk_blocks());
+                new_chunk_vertices_data[idx].second[i] =
+                    (it->second->get_chunk_blocks());
             } else {
-                neighbor_block[i] = nullptr;
+                new_chunk_vertices_data[idx].second[i] = std::nullopt;
             }
         }
-        chunk.gen_vertex_data(neighbor_block);
     }
 
+    std::for_each(
+        std::execution::par, new_chunk_vertices_data.begin(),
+        new_chunk_vertices_data.end(),
+        [](std::pair<Chunk*, OptionalBlockVectorArray>& new_chunk_data) {
+            auto& [chunk, neighbor_data] = new_chunk_data;
+            chunk->gen_vertex_data(neighbor_data);
+        });
+
     m_chunk_gen_fraction = 0.7f;
 
     build_neighbor_context_for_affected_neighbors(affected_neighbor,
                                                   new_chunks_neighbor);
 
     m_chunk_gen_fraction = 0.8f;
-
+    OptionalBlockVectorArray neighbor_block;
     for (auto& [pos, chunk] : affected_neighbor) {
         for (int i = 0; i < 4; i++) {
             auto it = new_chunks_neighbor.find(pos + CHUNK_DIR[i]);
             if (it != new_chunks_neighbor.end()) {
-                neighbor_block[i] = &(it->second->get_chunk_blocks());
+                neighbor_block[i] = (it->second->get_chunk_blocks());
             } else {
-                neighbor_block[i] = nullptr;
+                neighbor_block[i] = std::nullopt;
             }
         }
         chunk->gen_vertex_data(neighbor_block);
@@ -644,32 +600,53 @@ void World::sync_player_pos(glm::vec3& player_pos) {
     player_pos = m_gen_player_pos;
 }
 
-void World::compute_required_chunks(ChunkPosSet& required_chunks,
-                                    ChunkHashMap& temp_neighbor) {
+void World::compute_required_chunks(
+    ChunkPosSet& required_chunks, ChunkPairVector& temp_neighbor,
+    std::vector<ChunkPos>& need_gen_temp_chunks_pos) {
     glm::vec3 player_pos;
     sync_player_pos(player_pos);
 
     int x = std::floor(player_pos.x);
     int z = std::floor(player_pos.z);
     auto [chunk_x, chunk_z] = chunk_pos(x, z);
+    int radius = m_rendering_distance;
+    int r2 = radius * radius;
+    required_chunks.reserve(radius * radius);
 
-    required_chunks.reserve(m_rendering_distance * m_rendering_distance);
-    int half = m_rendering_distance / 2;
-    for (int u = chunk_x - half; u <= chunk_x + half; ++u) {
-        for (int v = chunk_z - half; v <= chunk_z + half; ++v) {
-            required_chunks.emplace(u, v);
+    for (int dx = -radius; dx <= radius; ++dx) {
+        for (int dz = -radius; dz <= radius; ++dz) {
+            if (dx * dx + dz * dz <= r2) {
+                required_chunks.emplace(chunk_x + dx, chunk_z + dz);
+            }
+        }
+    }
+    int new_radius = radius + 1;
+    int new_r2 = new_radius * new_radius;
+    for (int dx = -new_radius; dx <= new_radius; ++dx) {
+        for (int dz = -new_radius; dz <= new_radius; ++dz) {
+            if (dx * dx + dz * dz <= new_r2) {
+                int nx = chunk_x + dx;
+                int nz = chunk_z + dz;
+                auto it = required_chunks.find({nx, nz});
+                if (it == required_chunks.end()) {
+                    need_gen_temp_chunks_pos.push_back({nx, nz});
+                }
+            }
         }
     }
     int max_path_len = std::max(CavePath::step_max(), RiverPath::step_max());
-    half = std::ceil(static_cast<float>(max_path_len) / CHUNK_SIZE) * 2;
-    for (int u = chunk_x - half; u <= chunk_x + half; ++u) {
-        for (int v = chunk_z - half; v <= chunk_z + half; ++v) {
-            ChunkPos pos{u, v};
-            auto it = required_chunks.find(pos);
-            if (it != required_chunks.end()) {
-                continue;
+    radius = max_path_len / 2;
+    r2 = radius * radius;
+    for (int dx = -radius; dx <= radius; ++dx) {
+        for (int dz = -radius; dz <= radius; ++dz) {
+            if (dx * dx + dz * dz <= r2) {
+                ChunkPos pos{chunk_x + dx, chunk_z + dz};
+                auto it = required_chunks.find(pos);
+                if (it != required_chunks.end()) {
+                    continue;
+                }
+                temp_neighbor.emplace_back(pos, Chunk(*this, pos));
             }
-            temp_neighbor.emplace(pos, Chunk(*this, pos));
         }
     }
 }
@@ -696,7 +673,7 @@ void World::sync_and_collect_missing_chunks(
 
 void World::build_neighbor_context_for_new_chunks(
     ConstChunkMap& new_chunks_neighbor, ChunkPtrUpdateList& affected_neighbor,
-    const ChunkUpdateList& new_chunks) {
+    const ChunkPairVector& new_chunks) {
     {
         std::lock_guard lk(m_chunks_mutex);
         for (auto& [pos, chunk] : new_chunks) {
@@ -774,21 +751,6 @@ void World::need_gen() {
     m_gen_cv.notify_one();
 }
 
-bool World::is_aabb_in_frustum(const glm::vec3& center,
-                               const glm::vec3& half_extents) {
-    for (const auto& plane : m_planes) {
-        // distance
-        float d = glm::dot(glm::vec3(plane), center) + plane.w;
-        float r = half_extents.x * std::abs(plane.x) +
-                  half_extents.y * std::abs(plane.y) +
-                  half_extents.z * std::abs(plane.z);
-        if (d + r < 0) {
-            return false;
-        }
-    }
-    return true;
-}
-
 int World::get_block(const glm::ivec3& block_pos) const {
     auto [chunk_x, chunk_z] = chunk_pos(block_pos.x, block_pos.z);
     std::lock_guard lk(m_chunks_mutex);
@@ -917,6 +879,15 @@ void World::update(float delta_time) {
         }
         m_pending_delete_vbo.clear();
     }
+
+    {
+        std::lock_guard lk(m_delete_vao_mutex);
+        for (auto x : m_pending_delete_vao) {
+            glDeleteVertexArrays(1, &x);
+        }
+        m_pending_delete_vao.clear();
+    }
+
     {
         std::scoped_lock lk(m_chunks_mutex, m_new_chunk_queue_mutex);
         m_new_chunk.clear();
@@ -947,13 +918,13 @@ void World::update(float delta_time) {
         for (auto& [pos, chunk] : m_chunks) {
             if (chunk.is_dirty()) {
                 // the curial fator influence
-                std::array<const std::vector<BlockType>*, 4> neighbor_block;
+                OptionalBlockVectorArray neighbor_block;
                 for (int i = 0; i < 4; i++) {
                     auto it = m_chunks.find(pos + CHUNK_DIR[i]);
                     if (it != m_chunks.end()) {
-                        neighbor_block[i] = &(it->second.get_chunk_blocks());
+                        neighbor_block[i] = (it->second.get_chunk_blocks());
                     } else {
-                        neighbor_block[i] = nullptr;
+                        neighbor_block[i] = std::nullopt;
                     }
                 }
                 chunk.gen_vertex_data(neighbor_block);
@@ -964,10 +935,12 @@ void World::update(float delta_time) {
                     chunk.upload_to_gpu();
                 }
                 m_render_snapshots.push_back(
-                    {chunk.get_normal_vbo(), chunk.get_normal_vertices_sum(),
-                     chunk.get_cross_vbo(), chunk.get_cross_vertices_sum(),
-                     chunk.get_transparent_vbo(),
-                     chunk.get_transparent_vertices_sum(),
+                    {chunk.get_normal_vao(), chunk.get_normal_vertices_sum(),
+                     chunk.get_cross_vao(), chunk.get_cross_vertices_sum(),
+                     chunk.get_normal_discard_vao(),
+                     chunk.get_normal_discard_vertices_sum(),
+                     chunk.get_normal_blend_vao(),
+                     chunk.get_normal_blend_vertices_sum(),
                      glm::vec3(static_cast<float>(pos.x * CHUNK_SIZE) +
                                    static_cast<float>(CHUNK_SIZE / 2),
                                static_cast<float>(WORLD_SIZE_Y / 2),
@@ -986,6 +959,11 @@ void World::push_delete_vbo(GLuint vbo) {
     m_pending_delete_vbo.push_back(vbo);
 }
 
+void World::push_delete_vao(GLuint vao) {
+    std::lock_guard lk(m_delete_vao_mutex);
+    m_pending_delete_vao.push_back(vao);
+}
+
 void World::hot_reload() {
     auto& config = Config::get();
     int dist = config.get<int>("world.rendering_distance");
@@ -1024,4 +1002,8 @@ void World::rendering_distance(int rendering_distance) {
 
 CaveCarver& World::cave_carcer() { return m_cave_carcer; }
 RiverWorm& World::river_worm() { return m_river_worm; }
+std::vector<glm::vec4>& World::planes() { return m_planes; }
+std::vector<ChunkRenderSnapshot>& World::render_snapshots() {
+    return m_render_snapshots;
+};
 } // namespace Cubed

src/renderer.cpp

@@ -12,6 +12,7 @@
 #include "Cubed/tools/cubed_hash.hpp"
 #include "Cubed/tools/font.hpp"
 #include "Cubed/tools/log.hpp"
+#include "Cubed/tools/math_tools.hpp"
 #include "Cubed/tools/shader_tools.hpp"
 
 #include <GLFW/glfw3.h>
@@ -36,6 +37,11 @@ Renderer::~Renderer() {
     glDeleteFramebuffers(1, &m_fbo);
     glDeleteTextures(1, &m_screen_texture);
     glDeleteRenderbuffers(1, &m_depth_render_buffer);
+
+    glDeleteFramebuffers(1, &m_oit_fbo);
+    glDeleteTextures(1, &m_accum_texture);
+    glDeleteTextures(1, &m_reveal_texture);
+    glDeleteRenderbuffers(1, &m_oit_depth_render_buffer);
 }
 
 void Renderer::hot_reload() {
@@ -52,7 +58,7 @@ void Renderer::init() {
     Logger::info("Renderer: {}",
                  reinterpret_cast<const char*>(glGetString(GL_RENDERER)));
 
-    Shader world_shader{"world", "shaders/block_v_shader.glsl",
+    Shader world_shader{"normal_block", "shaders/block_v_shader.glsl",
                         "shaders/block_f_shader.glsl"};
     Shader outline_shader{"outline", "shaders/outline_v_shader.glsl",
                           "shaders/outline_f_shader.glsl"};
@@ -65,7 +71,11 @@ void Renderer::init() {
     Shader under_water_shader{"under_water",
                               "shaders/under_water_v_shader.glsl",
                               "shaders/under_water_f_shader.glsl"};
-
+    Shader accum_shader{"accum", "shaders/block_accumulation_v_shader.glsl",
+                        "shaders/block_accumulation_f_shader.glsl"};
+    Shader composite_block_shader{"composite",
+                                  "shaders/block_composite_v_shader.glsl",
+                                  "shaders/block_composite_f_shader.glsl"};
     m_shaders.insert({world_shader.hash(), std::move(world_shader)});
     m_shaders.insert({outline_shader.hash(), std::move(outline_shader)});
     m_shaders.insert({sky_shdaer.hash(), std::move(sky_shdaer)});
@@ -73,7 +83,9 @@ void Renderer::init() {
     m_shaders.insert({text_shdaer.hash(), std::move(text_shdaer)});
     m_shaders.insert(
         {under_water_shader.hash(), std::move(under_water_shader)});
-
+    m_shaders.insert({accum_shader.hash(), std::move(accum_shader)});
+    m_shaders.insert(
+        {composite_block_shader.hash(), std::move(composite_block_shader)});
     glEnable(GL_DEPTH_TEST);
     glDepthFunc(GL_LEQUAL);
 
@@ -94,20 +106,28 @@ void Renderer::init() {
     m_vao.resize(NUM_VAO);
     glGenVertexArrays(NUM_VAO, m_vao.data());
     glBindVertexArray(0);
-    glGenBuffers(1, &m_outline_vbo);
 
+    glBindVertexArray(m_vao[2]);
+    glGenBuffers(1, &m_outline_vbo);
     glBindBuffer(GL_ARRAY_BUFFER, m_outline_vbo);
     glBufferData(GL_ARRAY_BUFFER, sizeof(CUBE_VER), CUBE_VER, GL_STATIC_DRAW);
-
+    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 0, 0);
+    glEnableVertexAttribArray(0);
     glGenBuffers(1, &m_outline_indices_vbo);
     glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, m_outline_indices_vbo);
     glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(OUTLINE_CUBE_INDICES),
                  OUTLINE_CUBE_INDICES, GL_STATIC_DRAW);
+
+    glBindVertexArray(m_vao[1]);
     glGenBuffers(1, &m_sky_vbo);
     glBindBuffer(GL_ARRAY_BUFFER, m_sky_vbo);
     glBufferData(GL_ARRAY_BUFFER, sizeof(VERTICES_POS), VERTICES_POS,
                  GL_STATIC_DRAW);
 
+    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 0, 0);
+    glEnableVertexAttribArray(0);
+
+    glBindVertexArray(m_vao[3]);
     glGenBuffers(1, &m_ui_vbo);
     glBindBuffer(GL_ARRAY_BUFFER, m_ui_vbo);
 
@@ -120,13 +140,23 @@ void Renderer::init() {
     glBufferData(GL_ARRAY_BUFFER, m_ui.size() * sizeof(Vertex2D), m_ui.data(),
                  GL_STATIC_DRAW);
 
-    glGenBuffers(1, &m_text_vbo);
-    glBindBuffer(GL_ARRAY_BUFFER, m_text_vbo);
-    glBufferData(GL_ARRAY_BUFFER, sizeof(float) * 6 * 4, NULL, GL_DYNAMIC_DRAW);
-    glBindBuffer(GL_ARRAY_BUFFER, 0);
-    init_underwater();
+    glBindBuffer(GL_ARRAY_BUFFER, m_ui_vbo);
+    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, sizeof(Vertex2D), (void*)0);
+    glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, sizeof(Vertex2D),
+                          (void*)offsetof(Vertex2D, s));
+    glVertexAttribPointer(2, 1, GL_FLOAT, GL_FALSE, sizeof(Vertex2D),
+                          (void*)offsetof(Vertex2D, layer));
+
+    glEnableVertexAttribArray(0);
+    glEnableVertexAttribArray(1);
+    glEnableVertexAttribArray(2);
+
+    init_quad();
     init_text();
     hot_reload();
+
+    glBindVertexArray(0);
+    glBindBuffer(GL_ARRAY_BUFFER, 0);
 }
 
 const Shader& Renderer::get_shader(const std::string& name) const {
@@ -135,15 +165,27 @@ const Shader& Renderer::get_shader(const std::string& name) const {
     return it->second;
 }
 
-void Renderer::init_underwater() {
+void Renderer::init_quad() {
+    glBindVertexArray(m_vao[0]);
     glGenBuffers(1, &m_quad_vbo);
     glBindBuffer(GL_ARRAY_BUFFER, m_quad_vbo);
     glBufferData(GL_ARRAY_BUFFER, sizeof(QUAD_VERTICES), QUAD_VERTICES,
                  GL_STATIC_DRAW);
-    glBindBuffer(GL_ARRAY_BUFFER, 0);
+
+    glEnableVertexAttribArray(0);
+    glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 4 * sizeof(float),
+                          (void*)0);
+    glEnableVertexAttribArray(1);
+    glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 4 * sizeof(float),
+                          (void*)(2 * sizeof(float)));
 }
 
 void Renderer::init_text() {
+    glBindVertexArray(m_vao[4]);
+    glGenBuffers(1, &m_text_vbo);
+    glBindBuffer(GL_ARRAY_BUFFER, m_text_vbo);
+    glBufferData(GL_ARRAY_BUFFER, sizeof(float) * 6 * 4, NULL, GL_DYNAMIC_DRAW);
+
     const auto& shader = get_shader("text");
     Text::set_loc(shader);
     DebugCollector::get().init_text();
@@ -151,14 +193,12 @@ void Renderer::init_text() {
 
 void Renderer::render() {
     glBindFramebuffer(GL_FRAMEBUFFER, m_fbo);
+
     glClearColor(0.0, 0.0, 0.0, 1.0);
     glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 
-    glBindVertexArray(m_vao[0]);
     render_sky();
-    glBindVertexArray(m_vao[1]);
     render_world();
-    glBindVertexArray(m_vao[2]);
     render_outline();
 
     glBindFramebuffer(GL_FRAMEBUFFER, 0);
@@ -166,15 +206,10 @@ void Renderer::render() {
     glClearColor(0.0f, 0.0f, 0.0f, 1.0);
     glClear(GL_COLOR_BUFFER_BIT);
 
-    glBindVertexArray(m_vao[3]);
     render_underwater();
-    glEnable(GL_DEPTH_TEST);
 
-    glBindVertexArray(m_vao[4]);
     render_ui();
-    glBindVertexArray(m_vao[5]);
     render_text();
-    glBindVertexArray(0);
     render_dev_panel();
 }
 
@@ -182,23 +217,24 @@ void Renderer::render_outline() {
     const auto& shader = get_shader("outline");
     shader.use();
 
-    m_mv_loc = shader.loc("mv_matrix");
-    m_proj_loc = shader.loc("proj_matrix");
-
     const auto& block_pos = m_world.get_look_block_pos("TestPlayer");
 
     if (block_pos != std::nullopt) {
+
+        m_mv_loc = shader.loc("mv_matrix");
+        m_proj_loc = shader.loc("proj_matrix");
+
         m_m_mat =
             glm::translate(glm::mat4(1.0f), glm::vec3(block_pos.value().pos));
+
+        m_v_mat = m_camera.get_camera_lookat();
         m_mv_mat = m_v_mat * m_m_mat;
+
         glUniformMatrix4fv(m_mv_loc, 1, GL_FALSE, glm::value_ptr(m_mv_mat));
         glUniformMatrix4fv(m_proj_loc, 1, GL_FALSE, glm::value_ptr(m_p_mat));
 
-        glBindBuffer(GL_ARRAY_BUFFER, m_outline_vbo);
-        glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 0, 0);
-        glEnableVertexAttribArray(0);
+        glBindVertexArray(m_vao[2]);
 
-        glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, m_outline_indices_vbo);
         glEnable(GL_DEPTH_TEST);
         glDepthFunc(GL_LEQUAL);
         glLineWidth(4.0f);
@@ -222,9 +258,7 @@ void Renderer::render_sky() {
     glUniformMatrix4fv(m_mv_loc, 1, GL_FALSE, glm::value_ptr(m_mv_mat));
     glUniformMatrix4fv(m_proj_loc, 1, GL_FALSE, glm::value_ptr(m_p_mat));
 
-    glBindBuffer(GL_ARRAY_BUFFER, m_sky_vbo);
-    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 0, 0);
-    glEnableVertexAttribArray(0);
+    glBindVertexArray(m_vao[1]);
 
     glDisable(GL_DEPTH_TEST);
 
@@ -233,10 +267,18 @@ void Renderer::render_sky() {
 }
 
 void Renderer::render_text() {
+
+    glBindVertexArray(m_vao[4]);
+
     const auto& shader = get_shader("text");
+
     shader.use();
 
+    glEnable(GL_BLEND);
+    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
+
     glDisable(GL_DEPTH_TEST);
+
     m_proj_loc = shader.loc("projection");
 
     glUniformMatrix4fv(m_proj_loc, 1, GL_FALSE, glm::value_ptr(m_ui_proj));
@@ -254,30 +296,21 @@ void Renderer::render_ui() {
     shader.use();
 
     glDisable(GL_DEPTH_TEST);
-
+    glEnable(GL_BLEND);
+    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
     m_mv_loc = shader.loc("m_matrix");
     m_proj_loc = shader.loc("proj_matrix");
 
     glUniformMatrix4fv(m_mv_loc, 1, GL_FALSE, glm::value_ptr(m_ui_m_matrix));
     glUniformMatrix4fv(m_proj_loc, 1, GL_FALSE, glm::value_ptr(m_ui_proj));
 
-    glBindBuffer(GL_ARRAY_BUFFER, m_ui_vbo);
-    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, sizeof(Vertex2D), (void*)0);
-    glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, sizeof(Vertex2D),
-                          (void*)offsetof(Vertex2D, s));
-    glVertexAttribPointer(2, 1, GL_FLOAT, GL_FALSE, sizeof(Vertex2D),
-                          (void*)offsetof(Vertex2D, layer));
-
-    glEnableVertexAttribArray(0);
-    glEnableVertexAttribArray(1);
-    glEnableVertexAttribArray(2);
+    glBindVertexArray(m_vao[3]);
 
     glActiveTexture(GL_TEXTURE0);
     glBindTexture(GL_TEXTURE_2D_ARRAY, m_texture_manager.get_ui_array());
 
     glDrawArrays(GL_TRIANGLES, 0, 6);
     Tools::check_opengl_error();
-    glBindBuffer(GL_ARRAY_BUFFER, 0);
 
     glEnable(GL_DEPTH_TEST);
 }
@@ -285,13 +318,8 @@ void Renderer::render_ui() {
 void Renderer::render_underwater() {
     const auto& shader = get_shader("under_water");
     shader.use();
-    glBindBuffer(GL_ARRAY_BUFFER, m_quad_vbo);
-    glEnableVertexAttribArray(0);
-    glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 4 * sizeof(float),
-                          (void*)0);
-    glEnableVertexAttribArray(1);
-    glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 4 * sizeof(float),
-                          (void*)(2 * sizeof(float)));
+
+    glBindVertexArray(m_vao[0]);
 
     glUniform1i(shader.loc("u_sceneTexture"), 0);
     glUniform1f(shader.loc("u_time"), glfwGetTime());
@@ -330,6 +358,9 @@ void Renderer::updata_framebuffer(int width, int height) {
     if (m_fbo == 0) {
         glGenFramebuffers(1, &m_fbo);
     }
+    if (m_oit_fbo == 0) {
+        glGenFramebuffers(1, &m_oit_fbo);
+    }
     glBindFramebuffer(GL_FRAMEBUFFER, m_fbo);
 
     glDeleteTextures(1, &m_screen_texture);
@@ -357,14 +388,52 @@ void Renderer::updata_framebuffer(int width, int height) {
         Logger::info("Frame Buffer Complete!");
     }
     glBindFramebuffer(GL_FRAMEBUFFER, 0);
+
+    glBindFramebuffer(GL_FRAMEBUFFER, m_oit_fbo);
+    glDeleteTextures(1, &m_accum_texture);
+    glDeleteTextures(1, &m_reveal_texture);
+    glDeleteRenderbuffers(1, &m_oit_depth_render_buffer);
+    glGenTextures(1, &m_accum_texture);
+    glBindTexture(GL_TEXTURE_2D, m_accum_texture);
+    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA16F, width, height, 0, GL_RGBA,
+                 GL_HALF_FLOAT, NULL);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D,
+                           m_accum_texture, 0);
+    glGenTextures(1, &m_reveal_texture);
+    glBindTexture(GL_TEXTURE_2D, m_reveal_texture);
+    glTexImage2D(GL_TEXTURE_2D, 0, GL_R16F, width, height, 0, GL_RED,
+                 GL_HALF_FLOAT, NULL);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT1, GL_TEXTURE_2D,
+                           m_reveal_texture, 0);
+    glGenRenderbuffers(1, &m_oit_depth_render_buffer);
+    glBindRenderbuffer(GL_RENDERBUFFER, m_oit_depth_render_buffer);
+    glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH24_STENCIL8, width, height);
+    glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_STENCIL_ATTACHMENT,
+                              GL_RENDERBUFFER, m_oit_depth_render_buffer);
+    GLenum draw_buffer[] = {GL_COLOR_ATTACHMENT0, GL_COLOR_ATTACHMENT1};
+    glDrawBuffers(2, draw_buffer);
+    if (glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE) {
+        Logger::error("FBO incomplete after resize!");
+    } else {
+        Logger::info("Frame Buffer Complete!");
+    }
+    glBindFramebuffer(GL_FRAMEBUFFER, 0);
+
+    m_width = width;
+    m_height = height;
 }
 
 void Renderer::render_world() {
-    const auto& shader = get_shader("world");
-    shader.use();
+    const auto& normal_block_shader = get_shader("normal_block");
+    normal_block_shader.use();
+
+    m_mv_loc = normal_block_shader.loc("mv_matrix");
+    m_proj_loc = normal_block_shader.loc("proj_matrix");
 
-    m_mv_loc = shader.loc("mv_matrix");
-    m_proj_loc = shader.loc("proj_matrix");
     glActiveTexture(GL_TEXTURE0);
 
     m_m_mat = glm::translate(glm::mat4(1.0f), glm::vec3(0.0f, 0.0f, 0.0f));
@@ -373,7 +442,127 @@ void Renderer::render_world() {
     glUniformMatrix4fv(m_mv_loc, 1, GL_FALSE, glm::value_ptr(m_mv_mat));
     glUniformMatrix4fv(m_proj_loc, 1, GL_FALSE, glm::value_ptr(m_p_mat));
     m_mvp_mat = m_p_mat * m_mv_mat;
-    m_world.render(m_mvp_mat, m_texture_manager, m_camera.get_camera_pos());
+
+    auto& camera_pos = m_camera.get_camera_pos();
+    auto& m_planes = m_world.planes();
+    auto& m_render_snapshots = m_world.render_snapshots();
+
+    Math::extract_frustum_planes(m_mvp_mat, m_planes);
+
+    int rendered_sum = 0;
+    glEnable(GL_DEPTH_TEST);
+    for (const auto& snapshot : m_render_snapshots) {
+
+        if (Math::is_aabb_in_frustum(snapshot.center, snapshot.half_extents,
+                                     m_planes)) {
+            glBindTexture(GL_TEXTURE_2D_ARRAY,
+                          m_texture_manager.get_texture_array());
+
+            glBindVertexArray(snapshot.normal_vao);
+
+            glDrawArrays(GL_TRIANGLES, 0, snapshot.normal_vertices_count);
+
+            rendered_sum++;
+        }
+    }
+    // cross_plane and discard
+
+    for (const auto& snapshot : m_render_snapshots) {
+        if (!Math::is_aabb_in_frustum(snapshot.center, snapshot.half_extents,
+                                      m_planes)) {
+            continue;
+        }
+        glm::vec2 camera_pos_xz{camera_pos.x, camera_pos.z};
+        if (snapshot.cross_vertices_count != 0) {
+            glm::vec2 center_xz{snapshot.center.x, snapshot.center.z};
+            float dist2d = glm::distance(camera_pos_xz, center_xz);
+            if (dist2d <= CROSS_PLANE_DISTANCE * 16) {
+                glBindTexture(GL_TEXTURE_2D_ARRAY,
+                              m_texture_manager.get_cross_plane_array());
+
+                glBindVertexArray(snapshot.cross_vao);
+
+                glDrawArrays(GL_TRIANGLES, 0, snapshot.cross_vertices_count);
+            }
+        }
+        if (snapshot.normal_discard_vertices_count != 0) {
+            glBindTexture(GL_TEXTURE_2D_ARRAY,
+                          m_texture_manager.get_texture_array());
+            glBindVertexArray(snapshot.normal_discard_vao);
+
+            glDrawArrays(GL_TRIANGLES, 0,
+                         snapshot.normal_discard_vertices_count);
+        }
+    }
+
+    // copy depth buffer
+
+    glBindFramebuffer(GL_READ_FRAMEBUFFER, m_fbo);
+    glBindFramebuffer(GL_DRAW_FRAMEBUFFER, m_oit_fbo);
+    glBlitFramebuffer(0, 0, m_width, m_height, 0, 0, m_width, m_height,
+                      GL_DEPTH_BUFFER_BIT, GL_NEAREST);
+    glBindFramebuffer(GL_DRAW_FRAMEBUFFER, m_oit_fbo);
+
+    // pass one accumulate
+    auto& accum_shader = get_shader("accum");
+    accum_shader.use();
+
+    GLint mv_loc = accum_shader.loc("mv_matrix");
+    GLint proj_loc = accum_shader.loc("proj_matrix");
+
+    glUniformMatrix4fv(mv_loc, 1, GL_FALSE, glm::value_ptr(m_mv_mat));
+    glUniformMatrix4fv(proj_loc, 1, GL_FALSE, glm::value_ptr(m_p_mat));
+
+    glBindFramebuffer(GL_FRAMEBUFFER, m_oit_fbo);
+
+    glClearBufferfv(GL_COLOR, 0, glm::value_ptr(glm::vec4(0.0f)));
+    float one = 1.0f;
+    glClearBufferfv(GL_COLOR, 1, &one);
+
+    glEnable(GL_DEPTH_TEST);
+    glDepthMask(GL_FALSE);
+
+    glEnable(GL_BLEND);
+    glBlendFunci(0, GL_ONE, GL_ONE);
+
+    glBlendFunci(1, GL_ZERO, GL_ONE_MINUS_SRC_COLOR);
+    for (const auto& snapshot : m_render_snapshots) {
+        if (!Math::is_aabb_in_frustum(snapshot.center, snapshot.half_extents,
+                                      m_planes)) {
+            continue;
+        }
+
+        if (snapshot.normal_blend_vertices_count != 0) {
+            glBindTexture(GL_TEXTURE_2D_ARRAY,
+                          m_texture_manager.get_texture_array());
+            glBindVertexArray(snapshot.normal_blend_vao);
+
+            glDrawArrays(GL_TRIANGLES, 0, snapshot.normal_blend_vertices_count);
+        }
+    }
+    auto& composite_shader = get_shader("composite");
+    glDisable(GL_BLEND);
+    composite_shader.use();
+    glUniform1i(composite_shader.loc("u_accumTex"), 0);
+    glUniform1i(composite_shader.loc("u_revealTex"), 1);
+    glDisable(GL_DEPTH_TEST);
+    glDepthMask(GL_TRUE);
+    glEnable(GL_BLEND);
+    glBlendFunc(GL_ONE, GL_ONE_MINUS_SRC_ALPHA);
+
+    glBindVertexArray(m_vao[0]);
+
+    glActiveTexture(GL_TEXTURE0);
+    glBindTexture(GL_TEXTURE_2D, m_accum_texture);
+    glActiveTexture(GL_TEXTURE1);
+    glBindTexture(GL_TEXTURE_2D, m_reveal_texture);
+
+    glBindFramebuffer(GL_FRAMEBUFFER, m_fbo);
+    glDrawArrays(GL_TRIANGLES, 0, 6);
+    glBindVertexArray(0);
+
+    DebugCollector::get().report(
+        "rendered_chunk", "Rendered Chunk: " + std::to_string(rendered_sum));
 }
 
 void Renderer::render_dev_panel() {

src/tools/cubed_random.cpp

@@ -5,8 +5,15 @@ namespace Cubed {
 Random::Random() {}
 Random::Random(unsigned seed) { init(seed); }
 bool Random::random_bool(double probability) {
-    std::bernoulli_distribution dist(probability);
-    return dist(m_engine);
+    if (probability <= 0.0)
+        return false;
+    if (probability >= 1.0)
+        return true;
+
+    const double MAX_VAL = 4294967295.0;
+    unsigned threshold = static_cast<unsigned>(probability * MAX_VAL);
+
+    return m_engine() <= threshold;
 }
 
 std::mt19937& Random::engine() { return m_engine; }
@@ -18,12 +25,23 @@ void Random::init(unsigned seed) {
     m_engine.seed(seed);
 }
 int Random::random_int(int min, int max) {
-    std::uniform_int_distribution<int> dist(min, max);
-    return dist(m_engine);
+    unsigned range = static_cast<unsigned>(max - min) + 1;
+
+    const unsigned LIMIT =
+        (std::numeric_limits<unsigned>::max() / range) * range;
+    unsigned r;
+    do {
+        r = m_engine();
+    } while (r >= LIMIT);
+
+    return min + static_cast<int>(r % range);
 }
 float Random::random_float(float min, float max) {
-    std::uniform_real_distribution<float> dist(min, max);
-    return dist(m_engine);
-}
 
+    unsigned r = m_engine() >> 8;
+    float t = static_cast<float>(r) * (1.0f / 16777216.0f);
+    float result = min + t * (max - min);
+
+    return result;
+}
 } // namespace Cubed

src/tools/math_tools.cpp

@@ -45,6 +45,26 @@ float smootherstep(float edge0, float edge1, float x) {
     return x * x * x * (x * (6.0f * x - 15.0f) + 10.0f);
 }
 
+bool is_aabb_in_frustum(const glm::vec3& center, const glm::vec3& half_extents,
+                        const std::vector<glm::vec4>& planes) {
+    for (const auto& plane : planes) {
+        // distance
+        float d = glm::dot(glm::vec3(plane), center) + plane.w;
+        float r = half_extents.x * std::abs(plane.x) +
+                  half_extents.y * std::abs(plane.y) +
+                  half_extents.z * std::abs(plane.z);
+        if (d + r < 0) {
+            return false;
+        }
+    }
+    return true;
+}
+float deterministic_random(int x, int z, uint64_t seed) {
+    uint64_t h = seed;
+    h = h * 6364136223846793005ULL + (uint64_t)x;
+    h = h * 6364136223846793005ULL + (uint64_t)z;
+    return (float)(h >> 40) / (float)(1 << 24);
+}
 } // namespace Math
 
 } // namespace Cubed