feat(renderer): smooth shadow sun direction transitions using quantized directions and slerp

Introduce user-controllable shader on/off, shadow mode (rotated Poisson disk, 3x3 grid, or off), light cull face, and discard transparent in depth pass. Expose all settings in new dev panel "shader" tab. Move ambient strength slider to the new tab.

assets/shaders/block_f_shader.glsl

@@ -1,15 +1,125 @@
 #version 460
 
 in vec2 tc;
+in vec3 normal;
+in vec3 vert_pos;
+in vec4 FragPosLightSpace;
 flat in int tex_layer;
 out vec4 color;
+layout (binding = 0) uniform sampler2D shadowMap;
+layout (binding = 1) uniform sampler2DArray samp;
+
+uniform float ambientStrength;
+uniform vec3 sunlightColor;
+uniform vec3 sunlightDir;
+uniform bool shader_on;
+uniform int shadowMode;
+
+const vec2 poissonDisk[8] = vec2[](
+    vec2( 0.1440,  0.7659), vec2(-0.5761,  0.4479),
+    vec2(-0.3220, -0.6058), vec2( 0.5693, -0.4048),
+    vec2(-0.1276,  0.1657), vec2(-0.0649, -0.0165),
+    vec2( 0.2773, -0.0305), vec2(-0.1134, -0.2122)
+);
+
+float random(vec3 seed) {
+    return fract(sin(dot(seed, vec3(12.9898,78.233,45.5432))) * 43758.5453);
+}
+
+float ShadowCalculation(vec4 fragPosLightSpace, vec3 norm, vec3 lightDir)
+{
+
+    vec3 projCoords = fragPosLightSpace.xyz / fragPosLightSpace.w;
+
+    projCoords = projCoords * 0.5 + 0.5;
+    if (projCoords.x < 0.0 || projCoords.x > 1.0 ||
+        projCoords.y < 0.0 || projCoords.y > 1.0 ||
+        projCoords.z < 0.0 || projCoords.z > 1.0) {
+        return 0.0;
+    }
+    float currentDepth = projCoords.z;
+    vec2 texelSize = 1.0 / vec2(textureSize(shadowMap, 0));
+    float shadow = 0.0;
+    float bias =
+    max(
+        0.0003,
+        0.001 * (1.0 - dot(norm, lightDir))
+    );
+
+    if (shadowMode == 0) {
+        vec3 seed = vert_pos * 37.0 + sin(vert_pos * 91.7) * 13.0;
+        float angle = random(seed) * 6.2831853;; // 2*PI
+        float s = sin(angle), c = cos(angle);
+        mat2 rot = mat2(c, -s, s, c);
+
+        float radius = 0.7;
+
+        
+        const int samples = 8;
+        for (int i = 0; i < samples; ++i) {
+            vec2 offset = rot * poissonDisk[i] * radius * texelSize;
+            float pcfDepth = texture(shadowMap, projCoords.xy + offset).r;
+            shadow += (currentDepth - bias > pcfDepth ? 1.0 : 0.0);
+        }
+        shadow /= float(samples);
+    } else if (shadowMode == 1) {
+        for (int x = -1; x <= 1; ++x) {
+            for (int y = -1; y <= 1; ++y) {
+                vec2 offset = vec2(x, y) * texelSize;
+                float pcfDepth = texture(shadowMap, projCoords.xy + offset).r;
+                shadow += (currentDepth - bias > pcfDepth ? 1.0 : 0.0);
+            }
+        }
+        shadow /= 9.0;
+    } else if (shadowMode == 2) {
+        // pcf off
+        float pcfDepth =
+        texture(shadowMap, projCoords.xy).r;
+
+        shadow =
+        currentDepth - bias > pcfDepth
+            ? 1.0
+            : 0.0;
+    } else {
+        float pcfDepth =
+        texture(shadowMap, projCoords.xy).r;
+
+        shadow =
+        currentDepth - bias > pcfDepth
+            ? 1.0
+            : 0.0;
+    }
+
+   
+    return shadow;
+}
 
-layout (binding = 0) uniform sampler2DArray samp;
 
 void main(void) {
-    color = texture(samp, vec3(tc, tex_layer));
+    vec4 objectColor = texture(samp, vec3(tc, tex_layer));
-    if (color.a < 0.8) {
+
+    if (objectColor.a < 0.8) {
         discard;
     }
+    if (!shader_on) {
+        color = objectColor;
+        return;
+    }
+   
+
+    vec3 lightDir = normalize(-sunlightDir);
+    
+    vec3 ambient = ambientStrength * sunlightColor;
+    
+    vec3 norm = normalize(normal);
+    
+    float diff = max(dot(norm, lightDir), 0.0);
+    
+    vec3 diffuse = diff * sunlightColor;
+
+    float shadow = ShadowCalculation(FragPosLightSpace, norm, lightDir);  
+  
+    color = vec4((ambient + (1.0 - shadow) * (diffuse)) * objectColor.rgb, objectColor.a);
+
     //color = varyingColor;
 }

assets/shaders/block_v_shader.glsl

@@ -3,8 +3,12 @@
 layout (location = 0) in vec3 pos;
 layout (location = 1) in vec2 texCoord;
 layout (location = 2) in float layer;
+layout (location = 3) in vec3 aNormal;
 out vec2 tc;
+out vec3 normal;
+out vec3 vert_pos;
 flat out int tex_layer;
+out vec4 FragPosLightSpace;
 
 mat4 buildRotateX(float rad);
 mat4 buildRotateY(float rad);
@@ -13,13 +17,21 @@ mat4 buildTranslate(float x, float y, float z);
 
 uniform mat4 mv_matrix;
 uniform mat4 proj_matrix;
-
+uniform mat4 norm_matrix;
-
+uniform mat4 lightSpaceMatrix;
 
 void main(void) {
-    gl_Position = proj_matrix * mv_matrix * vec4(pos, 1.0);
+    vec4 viewPos = mv_matrix * vec4(pos, 1.0);
+
+    vert_pos = pos;
+
     tc = texCoord;
+    
     tex_layer = int(layer);
+    
+    normal = mat3(norm_matrix) * aNormal;
+    FragPosLightSpace = lightSpaceMatrix * vec4(pos, 1.0);
+    gl_Position = proj_matrix * viewPos;
 }
 
 mat4 buildTranslate(float x, float y, float z) {

assets/shaders/depth_fragment_shader.glsl

@@ -0,0 +1,16 @@
+#version 460
+
+in vec2 tc;
+flat in int tex_layer;
+layout (binding = 1) uniform sampler2DArray samp;
+
+uniform bool is_discard_tranparent;
+
+void main() {
+    if (is_discard_tranparent) {
+        vec4 texColor = texture(samp, vec3(tc, tex_layer));
+        if (texColor.a < 0.8) 
+            discard;
+    }   
+    //gl_FragDepth = gl_FragCoord.z; 
+}

assets/shaders/depth_shader.glsl

@@ -0,0 +1,12 @@
+#version 460
+layout (location = 0) in vec3 pos;
+layout (location = 1) in vec2 texCoord;
+layout (location = 2) in float layer;
+uniform mat4 lightSpaceMatrix;
+out vec2 tc;
+flat out int tex_layer;
+void main() {
+    tc = texCoord;
+    tex_layer = int(layer);
+    gl_Position = lightSpaceMatrix  * vec4(pos, 1.0);
+}

assets/shaders/sky_f_shader.glsl

@@ -2,8 +2,10 @@
 
 out vec4 frag_color;
 
+uniform vec3 color;
+
 void main(void) {
     
-    frag_color = vec4(0.529, 0.808, 0.922, 1.0);
+    frag_color = vec4(color, 1.0);
 
 }

include/Cubed/camera.hpp

@@ -32,6 +32,7 @@ public:
     const glm::vec3& get_camera_pos() const;
 
     bool is_under_water() const;
+    glm::vec3 get_camera_front() const;
 };
 
 } // namespace Cubed

include/Cubed/constants.hpp

@@ -23,9 +23,9 @@ constexpr float DEFAULT_MAX_RUN_SPEED = 7.0f;
 constexpr float DEFAULT_ACCELERATION = 10.0f;
 constexpr float DEFAULT_DECELERATION = 15.0f;
 constexpr float DEFAULT_G = 22.5f;
-static constexpr int SIZE_X = CHUNK_SIZE;
+constexpr int SIZE_X = CHUNK_SIZE;
-static constexpr int SIZE_Y = WORLD_SIZE_Y;
+constexpr int SIZE_Y = WORLD_SIZE_Y;
-static constexpr int SIZE_Z = CHUNK_SIZE;
+constexpr int SIZE_Z = CHUNK_SIZE;
 
 constexpr ChunkPos CHUNK_DIR[]{{1, 0}, {-1, 0}, {0, 1},  {0, -1},
                                {1, 1}, {-1, 1}, {1, -1}, {-1, -1}};

include/Cubed/dev_panel.hpp

@@ -44,14 +44,19 @@ private:
     bool m_need_save_config = false;
     bool m_gen_thread_running = true;
     int m_theme = 0;
+    int m_pre_set_day_tick = 0;
+    int m_pre_set_tick_speed = 1;
+    bool m_tick_frezze = false;
     void show_about_table_bar();
     void show_biome_table_bar();
+    void show_time_table_bar();
     void show_cave_table_bar();
     void show_river_table_bar();
     void show_settings_tab_item();
     void show_world_tab_item();
     void show_player_tab_item();
     void show_items_tab_item();
+    void show_shader_tab_item();
 
     void update_config_view();
     void update_player_profile();

include/Cubed/gameplay/game_time.hpp

@@ -0,0 +1,10 @@
+#pragma once
+
+// Prevent unsigned underflow issues in subtraction
+using TickType = long long;
+
+constexpr int DEFAULT_PER_TICK_TIME = 50;
+
+constexpr TickType DAY_TIME = 24000;
+
+constexpr TickType PER_HOUR = 1000;

include/Cubed/gameplay/vertex_data.hpp

@@ -7,7 +7,7 @@
 namespace Cubed {
 class World;
 struct VertexData {
-    std::vector<Vertex> m_vertices;
+    std::vector<Vertex3D> m_vertices;
     GLuint m_vbo = 0;
     GLuint m_vao = 0;
     std::atomic<std::size_t> m_sum{0};

include/Cubed/gameplay/world.hpp

@@ -2,6 +2,7 @@
 #include "Cubed/AABB.hpp"
 #include "Cubed/gameplay/cave_carver.hpp"
 #include "Cubed/gameplay/chunk.hpp"
+#include "Cubed/gameplay/game_time.hpp"
 #include "Cubed/gameplay/river_worm.hpp"
 
 #include <atomic>
@@ -39,12 +40,21 @@ private:
         std::unordered_map<ChunkPos, const Chunk*, ChunkPos::Hash>;
     using ChunkPosSet = std::unordered_set<ChunkPos, ChunkPos::Hash>;
     using ChunkHashMap = std::unordered_map<ChunkPos, Chunk, ChunkPos::Hash>;
+
     glm::vec3 m_gen_player_pos{0.0f, 0.0f, 0.0f};
     ChunkHashMap m_chunks;
     std::unordered_map<std::size_t, Player> m_players;
     std::vector<glm::vec4> m_planes;
 
     std::thread m_gen_thread;
+    std::thread m_server_thread;
+
+    std::stop_source m_server_stop_source;
+
+    std::atomic<int> m_per_tick_time = DEFAULT_PER_TICK_TIME; // ms
+
+    std::atomic<TickType> m_day_tick = 6000;
+
     mutable std::mutex m_chunks_mutex;
     std::mutex m_gen_signal_mutex;
     std::mutex m_new_chunk_queue_mutex;
@@ -59,8 +69,12 @@ private:
     std::atomic<bool> m_is_rebuilding{false};
     std::atomic<bool> m_chunk_gen_finished{false};
     std::atomic<bool> m_could_gen{true};
+    std::atomic<bool> m_tick_running{true};
     std::atomic<int> m_rendering_distance{24};
     std::atomic<float> m_chunk_gen_fraction{0.0f};
+
+    std::atomic<TickType> m_game_ticks{0};
+
     std::vector<ChunkPos> m_dirty_queue;
     std::vector<ChunkRenderSnapshot> m_render_snapshots;
     std::vector<std::pair<ChunkPos, Chunk>> m_new_chunk;
@@ -119,12 +133,25 @@ public:
     int rendering_distance() const;
     void rendering_distance(int rendering_distance);
     void start_gen_thread();
+    void start_server_thread();
     void stop_gen_thread();
+    void stop_server_thread();
+    void serever_run(std::stop_token stoken);
 
     CaveCarver& cave_carcer();
     RiverWorm& river_worm();
     std::vector<glm::vec4>& planes();
     std::vector<ChunkRenderSnapshot>& render_snapshots();
+
+    glm::vec3 sunlight_dir() const;
+    TickType game_tick() const;
+    TickType day_tick() const;
+    void day_tick(TickType tick);
+    int per_tick_time() const;
+    void per_tick_time(int ms);
+
+    bool is_tick_running() const;
+    void tick_running(bool run);
 };
 
 } // namespace Cubed

include/Cubed/primitive_data.hpp

@@ -91,6 +91,51 @@ constexpr float TEX_COORDS[6][6][2] = {
      {0.0f, 1.0f}, // back left
      {0.0f, 0.0f}} // front left
 };
+
+constexpr float NORMALS[6][6][3] = {
+    // ===== front (z = +1) =====
+    {{0.0f, 0.0f, 1.0f},
+     {0.0f, 0.0f, 1.0f},
+     {0.0f, 0.0f, 1.0f},
+     {0.0f, 0.0f, 1.0f},
+     {0.0f, 0.0f, 1.0f},
+     {0.0f, 0.0f, 1.0f}},
+    // ===== right (x = +1) =====
+    {{1.0f, 0.0f, 0.0f},
+     {1.0f, 0.0f, 0.0f},
+     {1.0f, 0.0f, 0.0f},
+     {1.0f, 0.0f, 0.0f},
+     {1.0f, 0.0f, 0.0f},
+     {1.0f, 0.0f, 0.0f}},
+    // ===== back (z = -1) =====
+    {{0.0f, 0.0f, -1.0f},
+     {0.0f, 0.0f, -1.0f},
+     {0.0f, 0.0f, -1.0f},
+     {0.0f, 0.0f, -1.0f},
+     {0.0f, 0.0f, -1.0f},
+     {0.0f, 0.0f, -1.0f}},
+    // ===== left (x = -1) =====
+    {{-1.0f, 0.0f, 0.0f},
+     {-1.0f, 0.0f, 0.0f},
+     {-1.0f, 0.0f, 0.0f},
+     {-1.0f, 0.0f, 0.0f},
+     {-1.0f, 0.0f, 0.0f},
+     {-1.0f, 0.0f, 0.0f}},
+    // ===== top (y = +1) =====
+    {{0.0f, 1.0f, 0.0f},
+     {0.0f, 1.0f, 0.0f},
+     {0.0f, 1.0f, 0.0f},
+     {0.0f, 1.0f, 0.0f},
+     {0.0f, 1.0f, 0.0f},
+     {0.0f, 1.0f, 0.0f}},
+    // ===== bottom (y = -1) =====
+    {{0.0f, -1.0f, 0.0f},
+     {0.0f, -1.0f, 0.0f},
+     {0.0f, -1.0f, 0.0f},
+     {0.0f, -1.0f, 0.0f},
+     {0.0f, -1.0f, 0.0f},
+     {0.0f, -1.0f, 0.0f}}};
+
 #pragma endregion
 constexpr float CUBE_VER[24] = {0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 1.0, 1.0,
                                 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0, 1.0,
@@ -148,6 +193,24 @@ constexpr float CROSS_TEX_COORDS[2][6][2] = {
      {1.0f, 1.0f},  // bottom right
      {0.0f, 1.0f}}, // bottom left
 };
+
+constexpr float CROSS_NORMALS[2][6][3] = {
+    // ===== Plane 1: upward =====
+    {{0.0f, 1.0f, 0.0f},
+     {0.0f, 1.0f, 0.0f},
+     {0.0f, 1.0f, 0.0f},
+     {0.0f, 1.0f, 0.0f},
+     {0.0f, 1.0f, 0.0f},
+     {0.0f, 1.0f, 0.0f}},
+
+    // ===== Plane 2: upward =====
+    {{0.0f, 1.0f, 0.0f},
+     {0.0f, 1.0f, 0.0f},
+     {0.0f, 1.0f, 0.0f},
+     {0.0f, 1.0f, 0.0f},
+     {0.0f, 1.0f, 0.0f},
+     {0.0f, 1.0f, 0.0f}}};
+
 #pragma endregion
 
 constexpr float QUAD_VERTICES[] = {
@@ -156,10 +219,11 @@ constexpr float QUAD_VERTICES[] = {
 
     -1.0f, 1.0f, 0.0f, 1.0f, 1.0f,  -1.0f, 1.0f, 0.0f, 1.0f, 1.0f,  1.0f, 1.0f};
 
-struct Vertex {
+struct Vertex3D {
     float x = 0.0f, y = 0.0f, z = 0.0f;
     float s = 0.0f, t = 0.0f;
     float layer = 0.0f;
+    float nx = 0.0f, ny = 0.0f, nz = 0.0f;
 };
 
 struct Vertex2D {

include/Cubed/renderer.hpp

@@ -28,13 +28,35 @@ public:
     void update_fov(float fov);
     void update_proj_matrix(float aspect, float width, float height);
     void updata_framebuffer(int width, int height);
+    float& ambient_strength();
+
+    bool& discard_transparent();
+    bool& shader_on();
+    int& shadow_mode();
+    int& light_cull_face();
 
 private:
+    static constexpr glm::vec3 SUNLIGHT_COLOR{1.0f, 1.0f, 1.0f};
+    static constexpr glm::vec3 SUN_COLOR{1.00f, 0.95f, 0.80f};
+    static constexpr glm::vec3 MOON_COLOR{0.75f, 0.80f, 1.00f};
+    static constexpr glm::vec3 SKY_COLOR{0.529, 0.808, 0.922};
+    static constexpr float FAR_PLANE = 1000.0f;
+    static constexpr float NEAR_PLANE = 0.1f;
+    static constexpr float SUN_SIZE = 50.0f;
+    static constexpr float MOON_SIZE = 50.0f;
+    static constexpr float DEPTH_MAP_SIZE = 4096.0f;
+    static constexpr float ANGLE_STEP_DEG = 0.5f;
+    float m_ambient_strength = 0.1f;
+
     const Camera& m_camera;
     DevPanel& m_dev_panel;
     const TextureManager& m_texture_manager;
     World& m_world;
 
+    bool m_discard_tranparent = true;
+    bool m_shader_on = true;
+    int m_shadow_mode = 0;
+    int m_light_cull_face = 0;
     float m_aspect = 0.0f;
     float m_fov = DEFAULT_FOV;
 
@@ -43,7 +65,7 @@ private:
     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;
+    glm::mat4 m_p_mat, m_v_mat, m_m_mat, m_mv_mat, m_mvp_mat, m_norm_mat;
 
     GLuint m_mv_loc = 0;
     GLuint m_proj_loc = 0;
@@ -62,18 +84,29 @@ private:
     GLuint m_accum_texture = 0;
     GLuint m_reveal_texture = 0;
     GLuint m_oit_depth_render_buffer = 0;
+
+    GLuint m_depth_map_fbo = 0;
+    GLuint m_depth_map_texture = 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;
 
+    glm::vec3 m_blend_from_sundir;
+    glm::vec3 m_blend_to_sundir;
+    float m_blend_t = 1.0f;
+    bool m_blend_initialized = false;
+    static constexpr float BLEND_DURATION = 0.15f;
+
     /*
     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;
@@ -88,6 +121,11 @@ private:
     void render_world();
     void render_underwater();
     void render_dev_panel();
+
+    glm::vec3 quantize_sun_direction(const glm::vec3& sundir,
+                                     float angle_step_deg) const;
+    glm::vec3 get_smoothed_shadow_sundir(const glm::vec3& raw_shadow_sundir,
+                                         float dt);
 };
 
 } // namespace Cubed

include/Cubed/tools/math_tools.hpp

@@ -12,6 +12,8 @@ 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);
+glm::vec3 slerp(const glm::vec3& from, const glm::vec3& to, float t);
+
 } // namespace Math
 
 } // namespace Cubed

src/camera.cpp

@@ -60,4 +60,6 @@ const glm::vec3& Camera::get_camera_pos() const { return m_camera_pos; }
 
 bool Camera::is_under_water() const { return m_under_water; }
 
+glm::vec3 Camera::get_camera_front() const { return m_player->get_front(); }
+
 } // namespace Cubed

src/dev_panel.cpp

@@ -84,6 +84,7 @@ void DevPanel::render() {
         show_world_tab_item();
         show_player_tab_item();
         show_items_tab_item();
+        show_shader_tab_item();
         show_about_table_bar();
 
         ImGui::EndTabBar();
@@ -107,6 +108,7 @@ void DevPanel::show_about_table_bar() {
         ImGui::Text("FreeType");
         ImGui::Text("toml++");
         ImGui::Text("Dear ImGui");
+        ImGui::Text("Tbb");
         ImGui::Separator();
         ImGui::Text("Special Thanks");
         ImGui::Text("TANGERIME");
@@ -263,6 +265,31 @@ void DevPanel::show_biome_table_bar() {
     }
 }
 
+void DevPanel::show_time_table_bar() {
+    World& world = m_app.world();
+    ImGui::Text("Game Tick %llu", world.game_tick());
+    ImGui::SameLine();
+    ImGui::Text("Day Tick %llu", world.day_tick());
+    m_tick_frezze = !world.is_tick_running();
+    ImGui::SameLine();
+    if (ImGui::Checkbox("Tick Frezze", &m_tick_frezze)) {
+        world.tick_running(!m_tick_frezze);
+    }
+    if (ImGui::SliderInt("SetDayTick", &m_pre_set_day_tick, 0, DAY_TIME)) {
+    }
+    ImGui::SameLine();
+    if (ImGui::Button("Set##DayTick")) {
+        world.day_tick(static_cast<TickType>(m_pre_set_day_tick));
+    }
+    ImGui::Text("MSPT %d", world.per_tick_time());
+    if (ImGui::SliderInt("SetMSPT", &m_pre_set_tick_speed, 1, 200)) {
+    }
+    ImGui::SameLine();
+    if (ImGui::Button("Set##MSPT")) {
+        world.per_tick_time(m_pre_set_tick_speed);
+    }
+}
+
 void DevPanel::show_cave_table_bar() {
     auto& cave_carcer = m_app.world().cave_carcer();
 
@@ -336,6 +363,7 @@ void DevPanel::show_settings_tab_item() {
                               static_cast<double>(m_config.mouse_sensitivity));
             m_player->hot_reload();
         }
+
         if (ImGui::SliderInt("Distance", &m_config.rendering_distance, 2,
                              128)) {
             Config::get().set("world.rendering_distance",
@@ -457,6 +485,10 @@ void DevPanel::show_world_tab_item() {
         ImGui::Text("Chunk Build Progress\n");
         ImGui::ProgressBar(m_app.world().chunk_gen_fraction());
         if (ImGui::BeginTabBar("World Settings")) {
+            if (ImGui::BeginTabItem("Time")) {
+                show_time_table_bar();
+                ImGui::EndTabItem();
+            }
             if (ImGui::BeginTabItem("Cave")) {
                 show_cave_table_bar();
                 ImGui::EndTabItem();
@@ -577,6 +609,27 @@ void DevPanel::show_items_tab_item() {
     }
 }
 
+void DevPanel::show_shader_tab_item() {
+
+    static const char* shader_mode[] = {"Rotated Poisson Disk PCF",
+                                        "3x3 Square Grid PCF", "PCF off"};
+    static const char* cull_face_mode[] = {"Front", "Back"};
+    if (ImGui::BeginTabItem("shader")) {
+        ImGui::Checkbox("Shader", &m_app.renderer().shader_on());
+        if (ImGui::SliderFloat("AmbientStrength",
+                               &m_app.renderer().ambient_strength(), 0.0f,
+                               0.35f))
+            ;
+        ImGui::Checkbox("Discard Transparent",
+                        &m_app.renderer().discard_transparent());
+        ImGui::Combo("ShaderMode", &m_app.renderer().shadow_mode(), shader_mode,
+                     IM_ARRAYSIZE(shader_mode));
+        ImGui::Combo("LightCullFaceMode", &m_app.renderer().light_cull_face(),
+                     cull_face_mode, IM_ARRAYSIZE(cull_face_mode));
+        ImGui::EndTabItem();
+    }
+}
+
 void DevPanel::update_config_view() {
     auto config = Config::get();
     m_config.fov =

src/gameplay/chunk.cpp

@@ -366,13 +366,18 @@ void Chunk::gen_vertices(const OptionalBlockVectorArray& neighbor_block) {
                                                  cur_id);
                     }
                     for (int i = 0; i < 6; i++) {
-                        Vertex vex = {
+                        Vertex3D vex = {
                             VERTICES_POS[face][i][0] + (float)world_x * 1.0f,
                             VERTICES_POS[face][i][1] + (float)world_y * 1.0f,
                             VERTICES_POS[face][i][2] + (float)world_z * 1.0f,
                             TEX_COORDS[face][i][0],
                             TEX_COORDS[face][i][1],
-                            static_cast<float>(cur_id * 6 + face)
+
+                            static_cast<float>(cur_id * 6 + face),
+
+                            NORMALS[face][i][0],
+                            NORMALS[face][i][1],
+                            NORMALS[face][i][2]
 
                         };
                         if (BlockManager::is_transparent(cur_id)) {
@@ -413,13 +418,16 @@ void Chunk::gen_cross_plane_vertices(int world_x, int world_y, int world_z,
     }
     for (int face = 0; face < 2; face++) {
         for (int i = 0; i < 6; i++) {
-            Vertex vex = {
+            Vertex3D vex = {
                 CROSS_VERTICES_POS[face][i][0] + (float)world_x * 1.0f,
                 CROSS_VERTICES_POS[face][i][1] + (float)world_y * 1.0f,
                 CROSS_VERTICES_POS[face][i][2] + (float)world_z * 1.0f,
                 CROSS_TEX_COORDS[face][i][0],
                 CROSS_TEX_COORDS[face][i][1],
-                static_cast<float>(BlockManager::cross_plane_index(id))
+                static_cast<float>(BlockManager::cross_plane_index(id)),
+                CROSS_NORMALS[face][i][0],
+                CROSS_NORMALS[face][i][1],
+                CROSS_NORMALS[face][i][2]
 
             };
             m_vertex_data[1].m_vertices.emplace_back(vex);

src/gameplay/vertex_data.cpp

@@ -41,18 +41,20 @@ void VertexData::upload() {
     }
     glBindVertexArray(m_vao);
     glBindBuffer(GL_ARRAY_BUFFER, m_vbo);
-    glBufferData(GL_ARRAY_BUFFER, m_vertices.size() * sizeof(Vertex),
+    glBufferData(GL_ARRAY_BUFFER, m_vertices.size() * sizeof(Vertex3D),
                  m_vertices.data(), GL_DYNAMIC_DRAW);
 
-    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, sizeof(Vertex), (void*)0);
+    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, sizeof(Vertex3D), (void*)0);
-    glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, sizeof(Vertex),
+    glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, sizeof(Vertex3D),
-                          (void*)offsetof(Vertex, s));
+                          (void*)offsetof(Vertex3D, s));
-    glVertexAttribPointer(2, 1, GL_FLOAT, GL_FALSE, sizeof(Vertex),
+    glVertexAttribPointer(2, 1, GL_FLOAT, GL_FALSE, sizeof(Vertex3D),
-                          (void*)offsetof(Vertex, layer));
+                          (void*)offsetof(Vertex3D, layer));
-
+    glVertexAttribPointer(3, 3, GL_FLOAT, GL_FALSE, sizeof(Vertex3D),
+                          (void*)offsetof(Vertex3D, nx));
     glEnableVertexAttribArray(0);
     glEnableVertexAttribArray(1);
     glEnableVertexAttribArray(2);
+    glEnableVertexAttribArray(3);
 
     glBindVertexArray(0);
     glBindBuffer(GL_ARRAY_BUFFER, 0);

src/gameplay/world.cpp

@@ -6,6 +6,9 @@
 #include "Cubed/tools/cubed_hash.hpp"
 
 #include <execution>
+#include <glm/gtc/constants.hpp>
+#include <numbers>
+using namespace std::chrono;
 
 namespace Cubed {
 
@@ -18,6 +21,7 @@ World::World() {}
 
 World::~World() {
     stop_gen_thread();
+    stop_server_thread();
     m_chunks.clear();
     {
         std::lock_guard lk(m_delete_vbo_mutex);
@@ -86,6 +90,8 @@ void World::init_world() {
     auto d = std::chrono::duration_cast<std::chrono::milliseconds>(t2 - t1);
     Logger::info("Chunk Block Init Finish, Time Consuming: {}", d);
 
+    start_server_thread();
+
     Logger::info("TestPlayer Create Finish");
 }
 void World::init_chunks() {
@@ -727,6 +733,11 @@ void World::start_gen_thread() {
     });
 }
 
+void World::start_server_thread() {
+    m_server_thread = std::thread(
+        [this]() { serever_run(m_server_stop_source.get_token()); });
+}
+
 void World::stop_gen_thread() {
     m_gen_running = false;
     m_gen_cv.notify_all();
@@ -736,6 +747,25 @@ void World::stop_gen_thread() {
     Logger::info("Gen Thread Stopped");
 }
 
+void World::stop_server_thread() {
+    m_server_stop_source.request_stop();
+    if (m_server_thread.joinable()) {
+        m_server_thread.join();
+    }
+}
+
+void World::serever_run(std::stop_token stoken) {
+    Logger::info("Server Thread Started!");
+    while (!stoken.stop_requested()) {
+        std::this_thread::sleep_for(milliseconds(m_per_tick_time));
+        if (m_tick_running) {
+            ++m_game_ticks;
+            m_day_tick = (m_day_tick + 1) % DAY_TIME;
+        }
+    }
+    Logger::info("Server Thread Stopped!");
+}
+
 void World::need_gen() {
     if (!m_could_gen) {
         Logger::warn("It is generating or consuming new chunks");
@@ -1006,4 +1036,49 @@ std::vector<glm::vec4>& World::planes() { return m_planes; }
 std::vector<ChunkRenderSnapshot>& World::render_snapshots() {
     return m_render_snapshots;
 };
+/*
+glm::vec3 World::sunlight_dir() const {
+    float t = static_cast<float>(m_day_tick) / DAY_TIME;
+
+    float azimuth = glm::radians(90.0f - t * 360.0f);
+
+    float altitude =
+        glm::half_pi<float>() * sin((t - 0.25f) * glm::two_pi<float>());
+
+    glm::vec3 dir{cos(altitude) * cos(azimuth), sin(altitude),
+                  cos(altitude) * sin(azimuth)};
+
+    return glm::normalize(-dir);
+}
+*/
+
+glm::vec3 World::sunlight_dir() const {
+    float altitude = sin((m_day_tick - 6 * PER_HOUR) /
+                         static_cast<float>(DAY_TIME / 2) * std::numbers::pi) *
+                     90.0f;
+
+    float t = static_cast<float>(m_day_tick) / DAY_TIME;
+    float azimuth = 90.0f - 360.0f * (t - 0.25f);
+
+    float alt = glm::radians(altitude);
+    float az = glm::radians(azimuth);
+    glm::vec3 dir;
+    dir.x = cos(alt) * sin(az);
+    dir.y = sin(alt);
+    dir.z = cos(alt) * cos(az);
+
+    return glm::normalize(-dir);
+}
+
+TickType World::game_tick() const { return m_game_ticks.load(); }
+TickType World::day_tick() const { return m_day_tick.load(); }
+void World::day_tick(TickType tick) {
+    tick %= DAY_TIME;
+    m_day_tick = tick;
+}
+int World::per_tick_time() const { return m_per_tick_time.load(); }
+void World::per_tick_time(int ms) { m_per_tick_time = ms; }
+
+bool World::is_tick_running() const { return m_tick_running.load(); }
+void World::tick_running(bool run) { m_tick_running = run; }
 } // namespace Cubed

src/renderer.cpp

@@ -18,6 +18,7 @@
 #include <GLFW/glfw3.h>
 #include <format>
 #include <glm/gtc/type_ptr.hpp>
+
 namespace Cubed {
 
 Renderer::Renderer(const Camera& camera, World& world,
@@ -42,6 +43,9 @@ Renderer::~Renderer() {
     glDeleteTextures(1, &m_accum_texture);
     glDeleteTextures(1, &m_reveal_texture);
     glDeleteRenderbuffers(1, &m_oit_depth_render_buffer);
+
+    glDeleteFramebuffers(1, &m_depth_map_fbo);
+    glDeleteTextures(1, &m_depth_map_texture);
 }
 
 void Renderer::hot_reload() {
@@ -76,6 +80,8 @@ void Renderer::init() {
     Shader composite_block_shader{"composite",
                                   "shaders/block_composite_v_shader.glsl",
                                   "shaders/block_composite_f_shader.glsl"};
+    Shader depth_shader{"depth_shader", "shaders/depth_shader.glsl",
+                        "shaders/depth_fragment_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)});
@@ -86,6 +92,7 @@ void Renderer::init() {
     m_shaders.insert({accum_shader.hash(), std::move(accum_shader)});
     m_shaders.insert(
         {composite_block_shader.hash(), std::move(composite_block_shader)});
+    m_shaders.insert({depth_shader.hash(), std::move(depth_shader)});
     glEnable(GL_DEPTH_TEST);
     glDepthFunc(GL_LEQUAL);
 
@@ -192,8 +199,8 @@ void Renderer::init_text() {
 }
 
 void Renderer::render() {
+    glDisable(GL_FRAMEBUFFER_SRGB);
     glBindFramebuffer(GL_FRAMEBUFFER, m_fbo);
-
     glClearColor(0.0, 0.0, 0.0, 1.0);
     glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 
@@ -202,12 +209,13 @@ void Renderer::render() {
     render_outline();
 
     glBindFramebuffer(GL_FRAMEBUFFER, 0);
+    glEnable(GL_FRAMEBUFFER_SRGB);
     glDisable(GL_DEPTH_TEST);
     glClearColor(0.0f, 0.0f, 0.0f, 1.0);
     glClear(GL_COLOR_BUFFER_BIT);
 
     render_underwater();
-
+    glDisable(GL_FRAMEBUFFER_SRGB);
     render_ui();
     render_text();
     render_dev_panel();
@@ -257,13 +265,44 @@ 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));
-
+    glUniform3fv(shader.loc("color"), 1, glm::value_ptr(SKY_COLOR));
     glBindVertexArray(m_vao[1]);
 
     glDisable(GL_DEPTH_TEST);
 
     glDrawArrays(GL_TRIANGLES, 0, 36);
     glEnable(GL_DEPTH_TEST);
+
+    // draw sun and moon
+    glDepthMask(GL_FALSE);
+
+    glBindVertexArray(m_vao[0]);
+    // draw sum
+    glm::vec3 sun_pos = m_camera.get_camera_pos() +
+                        normalize(-m_world.sunlight_dir()) * (FAR_PLANE * 0.9f);
+    glm::vec3 sun_view_pos = glm::vec3(m_v_mat * glm::vec4(sun_pos, 1.0f));
+    m_mv_mat = glm::translate(glm::mat4(1.0f), sun_view_pos) *
+               glm::scale(glm::mat4(1.0f), glm::vec3(SUN_SIZE)) *
+               glm::translate(glm::mat4(1.0f), glm::vec3(-0.5f, -0.5f, 0.0f));
+    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));
+    glUniform3fv(shader.loc("color"), 1, glm::value_ptr(SUN_COLOR));
+
+    glDrawArrays(GL_TRIANGLES, 0, 6);
+
+    glm::vec3 moon_pos = m_camera.get_camera_pos() +
+                         normalize(m_world.sunlight_dir()) * (FAR_PLANE * 0.9f);
+    glm::vec3 moon_view_pos = glm::vec3(m_v_mat * glm::vec4(moon_pos, 1.0f));
+    m_mv_mat = glm::translate(glm::mat4(1.0f), moon_view_pos) *
+               glm::scale(glm::mat4(1.0f), glm::vec3(MOON_SIZE)) *
+               glm::translate(glm::mat4(1.0f), glm::vec3(-0.5f, -0.5f, 0.0f));
+    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));
+    glUniform3fv(shader.loc("color"), 1, glm::value_ptr(MOON_COLOR));
+
+    glDrawArrays(GL_TRIANGLES, 0, 6);
+
+    glDepthMask(GL_TRUE);
 }
 
 void Renderer::render_text() {
@@ -343,7 +382,8 @@ void Renderer::update_fov(float fov) {
 
 void Renderer::update_proj_matrix(float aspect, float width, float height) {
     m_aspect = aspect;
-    m_p_mat = glm::perspective(glm::radians(m_fov), aspect, 0.1f, 1000.0f);
+    m_p_mat =
+        glm::perspective(glm::radians(m_fov), aspect, NEAR_PLANE, FAR_PLANE);
     m_ui_proj = glm::ortho(0.0f, width, height, 0.0f, -1.0f, 1.0f);
     // scale and then translate
     m_ui_m_matrix =
@@ -423,11 +463,146 @@ void Renderer::updata_framebuffer(int width, int height) {
     }
     glBindFramebuffer(GL_FRAMEBUFFER, 0);
 
+    // depth map fbo
+    if (m_depth_map_fbo == 0) {
+        glGenFramebuffers(1, &m_depth_map_fbo);
+    }
+    glDeleteTextures(1, &m_depth_map_texture);
+    glGenTextures(1, &m_depth_map_texture);
+
+    glBindTexture(GL_TEXTURE_2D, m_depth_map_texture);
+    glTexImage2D(GL_TEXTURE_2D, 0, GL_DEPTH_COMPONENT32F, DEPTH_MAP_SIZE,
+                 DEPTH_MAP_SIZE, 0, GL_DEPTH_COMPONENT, GL_FLOAT, NULL);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_BORDER);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_BORDER);
+    float border_color[] = {1.0f, 1.0f, 1.0f, 1.0f};
+    glTexParameterfv(GL_TEXTURE_2D, GL_TEXTURE_BORDER_COLOR, border_color);
+    // Manually compare shadows
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_COMPARE_MODE, GL_NONE);
+    // glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_COMPARE_MODE,
+    //                 GL_COMPARE_REF_TO_TEXTURE);
+    // glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_COMPARE_FUNC, GL_LEQUAL);
+
+    glBindFramebuffer(GL_FRAMEBUFFER, m_depth_map_fbo);
+    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_TEXTURE_2D,
+                           m_depth_map_texture, 0);
+    glDrawBuffer(GL_NONE);
+    glReadBuffer(GL_NONE);
+    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() {
+    // shader map
+    glm::mat4 light_space_matrix;
+    auto& m_render_snapshots = m_world.render_snapshots();
+    auto& camera_pos = m_camera.get_camera_pos();
+    if (m_shader_on) {
+        const auto& depth_shader = get_shader("depth_shader");
+        depth_shader.use();
+
+        glm::vec3 cam_pos = m_camera.get_camera_pos();
+        glm::vec3 cam_fwd = m_camera.get_camera_front();
+        float half_extent = 128.0f;
+
+        glm::vec3 center = cam_pos + cam_fwd * (half_extent * 0.5f);
+
+        glm::vec3 sundir = glm::normalize(m_world.sunlight_dir());
+        glm::vec3 raw_shadow_sundir =
+            quantize_sun_direction(sundir, ANGLE_STEP_DEG);
+        glm::vec3 shadow_sundir =
+            get_smoothed_shadow_sundir(raw_shadow_sundir, m_delta_time);
+        glm::vec3 up = fabs(shadow_sundir.y) > 0.99f ? glm::vec3(0, 0, 1)
+                                                     : glm::vec3(0, 1, 0);
+
+        glm::mat4 light_basis = glm::lookAt(glm::vec3(0.0f), shadow_sundir, up);
+        float texels_per_unit = DEPTH_MAP_SIZE / (half_extent * 2.0f);
+        glm::vec3 ls_center = glm::vec3(light_basis * glm::vec4(center, 1.0f));
+        ls_center.x =
+            std::round(ls_center.x * texels_per_unit) / texels_per_unit;
+        ls_center.y =
+            std::round(ls_center.y * texels_per_unit) / texels_per_unit;
+        glm::vec3 snapped_center =
+            glm::vec3(glm::inverse(light_basis) * glm::vec4(ls_center, 1.0f));
+
+        float distance = half_extent * 1.5f;
+        float near_plane = 1.0f;
+        float far_plane = distance + half_extent * 2.0f;
+        glm::vec3 light_pos = snapped_center - shadow_sundir * distance;
+        glm::mat4 light_view = glm::lookAt(light_pos, snapped_center, up);
+        glm::mat4 light_projection =
+            glm::ortho(-half_extent, half_extent, -half_extent, half_extent,
+                       near_plane, far_plane);
+
+        light_space_matrix = light_projection * light_view;
+        glUniformMatrix4fv(depth_shader.loc("lightSpaceMatrix"), 1, GL_FALSE,
+                           glm::value_ptr(light_space_matrix));
+        glUniform1i(depth_shader.loc("is_discard_tranparent"),
+                    m_discard_tranparent);
+        glViewport(0, 0, DEPTH_MAP_SIZE, DEPTH_MAP_SIZE);
+        if (m_light_cull_face == 0) {
+            glCullFace(GL_FRONT);
+        } else if (m_light_cull_face == 1) {
+            glCullFace(GL_BACK);
+        } else {
+            Logger::warn("Light Cull Face {} Over The Max Selection",
+                         m_light_cull_face);
+            glCullFace(GL_BACK);
+        }
+
+        glBindFramebuffer(GL_FRAMEBUFFER, m_depth_map_fbo);
+        glClear(GL_DEPTH_BUFFER_BIT);
+
+        glActiveTexture(GL_TEXTURE1);
+        glEnable(GL_DEPTH_TEST);
+        for (const auto& snapshot : m_render_snapshots) {
+            glBindTexture(GL_TEXTURE_2D_ARRAY,
+                          m_texture_manager.get_texture_array());
+            glBindVertexArray(snapshot.normal_vao);
+
+            glDrawArrays(GL_TRIANGLES, 0, snapshot.normal_vertices_count);
+        }
+
+        // cross_plane and discard
+
+        for (const auto& snapshot : m_render_snapshots) {
+
+            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_texture_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);
+            }
+        }
+    }
+
+    glBindFramebuffer(GL_FRAMEBUFFER, m_fbo);
+
+    glCullFace(GL_BACK);
+    glViewport(0, 0, m_width, m_height);
     const auto& normal_block_shader = get_shader("normal_block");
     normal_block_shader.use();
 
@@ -435,17 +610,32 @@ void Renderer::render_world() {
     m_proj_loc = normal_block_shader.loc("proj_matrix");
 
     glActiveTexture(GL_TEXTURE0);
+    glBindTexture(GL_TEXTURE_2D, m_depth_map_texture);
+    glActiveTexture(GL_TEXTURE1);
 
     m_m_mat = glm::translate(glm::mat4(1.0f), glm::vec3(0.0f, 0.0f, 0.0f));
     m_v_mat = m_camera.get_camera_lookat();
     m_mv_mat = m_v_mat * m_m_mat;
+    m_norm_mat = glm::transpose(glm::inverse(m_mv_mat));
+    glm::vec3 light_dir_view =
+        glm::normalize(glm::mat3(m_v_mat) * m_world.sunlight_dir());
+
     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));
+    glUniformMatrix4fv(normal_block_shader.loc("norm_matrix"), 1, GL_FALSE,
+                       glm::value_ptr(m_norm_mat));
+    glUniformMatrix4fv(normal_block_shader.loc("lightSpaceMatrix"), 1, GL_FALSE,
+                       glm::value_ptr(light_space_matrix));
+    glUniform1f(normal_block_shader.loc("ambientStrength"), m_ambient_strength);
+    glUniform3fv(normal_block_shader.loc("sunlightColor"), 1,
+                 glm::value_ptr(SUNLIGHT_COLOR));
+    glUniform3fv(normal_block_shader.loc("sunlightDir"), 1,
+                 glm::value_ptr(light_dir_view));
+    glUniform1i(normal_block_shader.loc("shadowMode"), m_shadow_mode);
+    glUniform1i(normal_block_shader.loc("shader_on"), m_shader_on);
     m_mvp_mat = m_p_mat * m_mv_mat;
 
-    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);
 
@@ -526,6 +716,7 @@ void Renderer::render_world() {
     glBlendFunci(0, GL_ONE, GL_ONE);
 
     glBlendFunci(1, GL_ZERO, GL_ONE_MINUS_SRC_COLOR);
+    glActiveTexture(GL_TEXTURE0);
     for (const auto& snapshot : m_render_snapshots) {
         if (!Math::is_aabb_in_frustum(snapshot.center, snapshot.half_extents,
                                       m_planes)) {
@@ -571,4 +762,56 @@ void Renderer::render_dev_panel() {
     glEnable(GL_DEPTH_TEST);
 }
 
+glm::vec3 Renderer::quantize_sun_direction(const glm::vec3& sundir,
+                                           float angle_step_deg) const {
+    float elevation = std::asin(glm::clamp(sundir.y, -1.0f, 1.0f));
+    float azimuth = std::atan2(sundir.z, sundir.x);
+
+    float step = glm::radians(angle_step_deg);
+
+    float quantized_elevation = std::round(elevation / step) * step;
+    float quantized_azimuth = std::round(azimuth / step) * step;
+
+    glm::vec3 quantized_dir;
+    quantized_dir.x =
+        std::cos(quantized_elevation) * std::cos(quantized_azimuth);
+    quantized_dir.z =
+        std::cos(quantized_elevation) * std::sin(quantized_azimuth);
+    quantized_dir.y = std::sin(quantized_elevation);
+
+    return glm::normalize(quantized_dir);
+}
+
+glm::vec3
+Renderer::get_smoothed_shadow_sundir(const glm::vec3& raw_shadow_sundir,
+                                     float dt) {
+    if (!m_blend_initialized) {
+
+        m_blend_from_sundir = raw_shadow_sundir;
+        m_blend_to_sundir = raw_shadow_sundir;
+        m_blend_t = 1.0f;
+        m_blend_initialized = true;
+        return raw_shadow_sundir;
+    }
+
+    if (raw_shadow_sundir != m_blend_to_sundir) {
+        glm::vec3 current_displayed = glm::normalize(
+            Math::slerp(m_blend_from_sundir, m_blend_to_sundir, m_blend_t));
+
+        m_blend_from_sundir = current_displayed;
+        m_blend_to_sundir = raw_shadow_sundir;
+        m_blend_t = 0.0f;
+    }
+
+    m_blend_t = glm::min(m_blend_t + dt / BLEND_DURATION, 1.0f);
+
+    return glm::normalize(
+        Math::slerp(m_blend_from_sundir, m_blend_to_sundir, m_blend_t));
+}
+
+float& Renderer::ambient_strength() { return m_ambient_strength; }
+bool& Renderer::discard_transparent() { return m_discard_tranparent; }
+bool& Renderer::shader_on() { return m_shader_on; }
+int& Renderer::shadow_mode() { return m_shadow_mode; }
+int& Renderer::light_cull_face() { return m_light_cull_face; }
 } // namespace Cubed

src/texture_manager.cpp

@@ -164,6 +164,8 @@ void TextureManager::init_block() {
     glTexParameteri(GL_TEXTURE_2D_ARRAY, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
     glTexParameteri(GL_TEXTURE_2D_ARRAY, GL_TEXTURE_MIN_FILTER,
                     GL_LINEAR_MIPMAP_LINEAR);
+    glTexParameteri(GL_TEXTURE_2D_ARRAY, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
+    glTexParameteri(GL_TEXTURE_2D_ARRAY, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
     glGenerateMipmap(GL_TEXTURE_2D_ARRAY);
     if (m_aniso >= 1) {
         glTexParameterf(GL_TEXTURE_2D_ARRAY, GL_TEXTURE_MAX_ANISOTROPY,

src/tools/math_tools.cpp

@@ -1,7 +1,9 @@
 #include "Cubed/tools/math_tools.hpp"
 
 #include <algorithm>
+#include <glm/glm.hpp>
 #include <glm/gtc/type_ptr.hpp>
+
 namespace Cubed {
 
 namespace Math {
@@ -65,6 +67,39 @@ float deterministic_random(int x, int z, uint64_t seed) {
     h = h * 6364136223846793005ULL + (uint64_t)z;
     return (float)(h >> 40) / (float)(1 << 24);
 }
+
+glm::vec3 slerp(const glm::vec3& from, const glm::vec3& to, float t) {
+
+    float cos_theta = glm::clamp(glm::dot(from, to), -1.0f, 1.0f);
+
+    if (cos_theta > 0.9995f) {
+        return glm::normalize(glm::mix(from, to, t));
+    }
+
+    if (cos_theta < -0.9995f) {
+
+        glm::vec3 axis = (std::fabs(from.x) < 0.9f)
+                             ? glm::vec3(1.0f, 0.0f, 0.0f)
+                             : glm::vec3(0.0f, 1.0f, 0.0f);
+        glm::vec3 ortho = glm::normalize(glm::cross(from, axis));
+
+        float angle = glm::pi<float>() * t;
+
+        glm::vec3 rotated =
+            from * std::cos(angle) + glm::cross(ortho, from) * std::sin(angle);
+
+        return glm::normalize(rotated);
+    }
+
+    float theta = std::acos(cos_theta);
+    float sin_theta = std::sin(theta);
+
+    float a = std::sin((1.0f - t) * theta) / sin_theta;
+    float b = std::sin(t * theta) / sin_theta;
+
+    return glm::normalize(a * from + b * to);
+}
+
 } // namespace Math
 
 } // namespace Cubed