Add include guards and header comments to sources

52 files changed, 386 insertions, 6 deletions

diff --git a/src/game/shared/const.hh b/src/game/shared/const.hh
index 187962a..45e1731 100644
--- a/src/game/shared/const.hh
+++ b/src/game/shared/const.hh
@@ -1,3 +1,10 @@
+// SPDX-License-Identifier: BSD-2-Clause
+// Copyright (c) 2025 Kirill Dmitrievich
+// File: const.hh
+// Description: Constants
+
+#ifndef SHARED_CONST_HH
+#define SHARED_CONST_HH
 #pragma once
 
 #include "core/math/constexpr.hh"
@@ -41,3 +48,5 @@ constexpr static glm::vec<2, T> ZERO_VEC2 = glm::vec<2, T>(0, 0);
 
 template<typename T>
 constexpr static glm::vec<3, T> ZERO_VEC3 = glm::vec<3, T>(0, 0, 0);
+
+#endif
diff --git a/src/game/shared/coord.hh b/src/game/shared/coord.hh
index 9d9be18..bd66c9b 100644
--- a/src/game/shared/coord.hh
+++ b/src/game/shared/coord.hh
@@ -1,3 +1,10 @@
+// SPDX-License-Identifier: BSD-2-Clause
+// Copyright (c) 2025 Kirill Dmitrievich
+// File: coord.hh
+// Description: Coordinate domain change functions
+
+#ifndef SHARED_COORD_HH
+#define SHARED_COORD_HH
 #pragma once
 
 #include "shared/const.hh"
@@ -143,3 +150,5 @@ inline constexpr glm::fvec3 coord::to_fvec3(const chunk_pos& cpos, const glm::fv
         fpos.z + static_cast<float>(cpos.z << CHUNK_BITSHIFT),
     };
 }
+
+#endif
diff --git a/src/game/shared/entity/collision.cc b/src/game/shared/entity/collision.cc
index 322bb91..6878958 100644
--- a/src/game/shared/entity/collision.cc
+++ b/src/game/shared/entity/collision.cc
@@ -1,3 +1,8 @@
+// SPDX-License-Identifier: BSD-2-Clause
+// Copyright (c) 2025 Kirill Dmitrievich
+// File: collision.cc
+// Description: Collision detection
+
 #include "shared/pch.hh"
 
 #include "shared/entity/collision.hh"
diff --git a/src/game/shared/entity/collision.hh b/src/game/shared/entity/collision.hh
index 34a648c..89d9756 100644
--- a/src/game/shared/entity/collision.hh
+++ b/src/game/shared/entity/collision.hh
@@ -1,3 +1,10 @@
+// SPDX-License-Identifier: BSD-2-Clause
+// Copyright (c) 2025 Kirill Dmitrievich
+// File: collision.hh
+// Description: Collision detection
+
+#ifndef SHARED_ENTITY_COLLISION_HH
+#define SHARED_ENTITY_COLLISION_HH
 #pragma once
 
 #include "core/math/aabb.hh"
@@ -13,3 +20,5 @@ public:
     // because both transform and velocity may be updated internally
     static void fixed_update(Dimension* dimension);
 };
+
+#endif
diff --git a/src/game/shared/entity/factory.cc b/src/game/shared/entity/factory.cc
index f2031df..223e593 100644
--- a/src/game/shared/entity/factory.cc
+++ b/src/game/shared/entity/factory.cc
@@ -1,3 +1,8 @@
+// SPDX-License-Identifier: BSD-2-Clause
+// Copyright (c) 2025 Kirill Dmitrievich
+// File: factory.cc
+// Description: Boilerplate entity creation
+
 #include "shared/pch.hh"
 
 #include "shared/entity/factory.hh"
diff --git a/src/game/shared/entity/factory.hh b/src/game/shared/entity/factory.hh
index 7c94136..158b187 100644
--- a/src/game/shared/entity/factory.hh
+++ b/src/game/shared/entity/factory.hh
@@ -1,3 +1,10 @@
+// SPDX-License-Identifier: BSD-2-Clause
+// Copyright (c) 2025 Kirill Dmitrievich
+// File: factory.hh
+// Description: Boilerplate entity creation
+
+#ifndef SHARED_ENTITY_FACTORY_HH
+#define SHARED_ENTITY_FACTORY_HH
 #pragma once
 
 class Dimension;
@@ -6,3 +13,5 @@ namespace shared
 {
 void create_player(Dimension* dimension, entt::entity entity);
 } // namespace shared
+
+#endif
diff --git a/src/game/shared/entity/gravity.cc b/src/game/shared/entity/gravity.cc
index 6a5145f..893e819 100644
--- a/src/game/shared/entity/gravity.cc
+++ b/src/game/shared/entity/gravity.cc
@@ -1,3 +1,8 @@
+// SPDX-License-Identifier: BSD-2-Clause
+// Copyright (c) 2025 Kirill Dmitrievich
+// File: gravity.cc
+// Description: Gravity component
+
 #include "shared/pch.hh"
 
 #include "shared/entity/gravity.hh"
diff --git a/src/game/shared/entity/gravity.hh b/src/game/shared/entity/gravity.hh
index 38b3c9b..c6ad701 100644
--- a/src/game/shared/entity/gravity.hh
+++ b/src/game/shared/entity/gravity.hh
@@ -1,3 +1,10 @@
+// SPDX-License-Identifier: BSD-2-Clause
+// Copyright (c) 2025 Kirill Dmitrievich
+// File: gravity.hh
+// Description: Gravity component
+
+#ifndef SHARED_ENTITY_GRAVITY_HH
+#define SHARED_ENTITY_GRAVITY_HH
 #pragma once
 
 class Dimension;
@@ -6,3 +13,5 @@ struct Gravity final {
 public:
     static void fixed_update(Dimension* dimension);
 };
+
+#endif
diff --git a/src/game/shared/entity/grounded.hh b/src/game/shared/entity/grounded.hh
index 7307e79..38367ec 100644
--- a/src/game/shared/entity/grounded.hh
+++ b/src/game/shared/entity/grounded.hh
@@ -1,3 +1,10 @@
+// SPDX-License-Identifier: BSD-2-Clause
+// Copyright (c) 2025 Kirill Dmitrievich
+// File: grounded.hh
+// Description: Flag components for entites that rest on the ground
+
+#ifndef SHARED_ENTITY_GROUNDED_HH
+#define SHARED_ENTITY_GROUNDED_HH
 #pragma once
 
 #include "shared/world/voxel.hh"
@@ -7,3 +14,5 @@
 struct Grounded final {
     VoxelMaterial surface;
 };
+
+#endif
diff --git a/src/game/shared/entity/head.hh b/src/game/shared/entity/head.hh
index 9fa71d9..cec3be4 100644
--- a/src/game/shared/entity/head.hh
+++ b/src/game/shared/entity/head.hh
@@ -1,3 +1,10 @@
+// SPDX-License-Identifier: BSD-2-Clause
+// Copyright (c) 2025 Kirill Dmitrievich
+// File: head.hh
+// Description: Head component
+
+#ifndef SHARED_ENTITY_HEAD_HH
+#define SHARED_ENTITY_HEAD_HH
 #pragma once
 
 struct Head {
@@ -11,3 +18,5 @@ namespace client
 struct HeadIntr final : public Head {};
 struct HeadPrev final : public Head {};
 } // namespace client
+
+#endif
diff --git a/src/game/shared/entity/player.hh b/src/game/shared/entity/player.hh
index d7cd020..8edba5e 100644
--- a/src/game/shared/entity/player.hh
+++ b/src/game/shared/entity/player.hh
@@ -1,3 +1,12 @@
+// SPDX-License-Identifier: BSD-2-Clause
+// Copyright (c) 2025 Kirill Dmitrievich
+// File: player.hh
+// Description: Flag components for entites that are players
+
+#ifndef SHARED_ENTITY_PLAYER_HH
+#define SHARED_ENTITY_PLAYER_HH
 #pragma once
 
 struct Player final {};
+
+#endif
diff --git a/src/game/shared/entity/stasis.cc b/src/game/shared/entity/stasis.cc
index 0b8a0c8..72f7592 100644
--- a/src/game/shared/entity/stasis.cc
+++ b/src/game/shared/entity/stasis.cc
@@ -1,3 +1,8 @@
+// SPDX-License-Identifier: BSD-2-Clause
+// Copyright (c) 2025 Kirill Dmitrievich
+// File: stasis.cc
+// Description: Freeze entites that are in an unloaded chunk
+
 #include "shared/pch.hh"
 
 #include "shared/entity/stasis.hh"
diff --git a/src/game/shared/entity/stasis.hh b/src/game/shared/entity/stasis.hh
index 5adc592..dfb97b3 100644
--- a/src/game/shared/entity/stasis.hh
+++ b/src/game/shared/entity/stasis.hh
@@ -1,3 +1,10 @@
+// SPDX-License-Identifier: BSD-2-Clause
+// Copyright (c) 2025 Kirill Dmitrievich
+// File: stasis.hh
+// Description: Freeze entites that are in an unloaded chunk
+
+#ifndef SHARED_ENTITY_STASIS_HH
+#define SHARED_ENTITY_STASIS_HH
 #pragma once
 
 class Dimension;
@@ -8,3 +15,5 @@ struct Stasis final {
 public:
     static void fixed_update(Dimension* dimension);
 };
+
+#endif
diff --git a/src/game/shared/entity/transform.cc b/src/game/shared/entity/transform.cc
index cf09e2f..2ceee0d 100644
--- a/src/game/shared/entity/transform.cc
+++ b/src/game/shared/entity/transform.cc
@@ -1,3 +1,8 @@
+// SPDX-License-Identifier: BSD-2-Clause
+// Copyright (c) 2025 Kirill Dmitrievich
+// File: transform.cc
+// Description: Transform component
+
 #include "shared/pch.hh"
 
 #include "shared/entity/transform.hh"
diff --git a/src/game/shared/entity/transform.hh b/src/game/shared/entity/transform.hh
index afbe9fa..55a00ac 100644
--- a/src/game/shared/entity/transform.hh
+++ b/src/game/shared/entity/transform.hh
@@ -1,3 +1,10 @@
+// SPDX-License-Identifier: BSD-2-Clause
+// Copyright (c) 2025 Kirill Dmitrievich
+// File: transform.hh
+// Description: Transform component
+
+#ifndef SHARED_ENTITY_TRANSFORM_HH
+#define SHARED_ENTITY_TRANSFORM_HH
 #pragma once
 
 #include "shared/types.hh"
@@ -22,3 +29,5 @@ namespace client
 struct TransformIntr final : public Transform {};
 struct TransformPrev final : public Transform {};
 } // namespace client
+
+#endif
diff --git a/src/game/shared/entity/velocity.cc b/src/game/shared/entity/velocity.cc
index 6fb8c80..c08b749 100644
--- a/src/game/shared/entity/velocity.cc
+++ b/src/game/shared/entity/velocity.cc
@@ -1,3 +1,8 @@
+// SPDX-License-Identifier: BSD-2-Clause
+// Copyright (c) 2025 Kirill Dmitrievich
+// File: velocity.cc
+// Description: Velocity component
+
 #include "shared/pch.hh"
 
 #include "shared/entity/velocity.hh"
diff --git a/src/game/shared/entity/velocity.hh b/src/game/shared/entity/velocity.hh
index 0266bd0..8dccf09 100644
--- a/src/game/shared/entity/velocity.hh
+++ b/src/game/shared/entity/velocity.hh
@@ -1,3 +1,10 @@
+// SPDX-License-Identifier: BSD-2-Clause
+// Copyright (c) 2025 Kirill Dmitrievich
+// File: velocity.hh
+// Description: Velocity component
+
+#ifndef SHARED_ENTITY_VELOCITY_HH
+#define SHARED_ENTITY_VELOCITY_HH
 #pragma once
 
 class Dimension;
@@ -18,3 +25,5 @@ namespace client
 struct VelocityIntr final : public Velocity {};
 struct VelocityPrev final : public Velocity {};
 } // namespace client
+
+#endif
diff --git a/src/game/shared/game.cc b/src/game/shared/game.cc
index e839e6a..bac92fb 100644
--- a/src/game/shared/game.cc
+++ b/src/game/shared/game.cc
@@ -1,3 +1,8 @@
+// SPDX-License-Identifier: BSD-2-Clause
+// Copyright (c) 2025 Kirill Dmitrievich
+// File: game.cc
+// Description: Shared initialization logic
+
 #include "shared/pch.hh"
 
 #include "shared/game.hh"
@@ -81,7 +86,7 @@ void shared_game::init(int argc, char** argv, std::string_view logfile)
     logger->flush();
 
     if(!PHYSFS_init(argv[0])) {
-        spdlog::critical("physfs: init failed: {}", physfs_error());
+        spdlog::critical("physfs: init failed: {}", physfs::last_error());
         std::terminate();
     }
 
@@ -96,17 +101,17 @@ void shared_game::init(int argc, char** argv, std::string_view logfile)
     std::filesystem::create_directories(userpath, ignore_error);
 
     if(!PHYSFS_mount(gamepath.string().c_str(), nullptr, false)) {
-        spdlog::critical("physfs: mount {} failed: {}", gamepath.string(), physfs_error());
+        spdlog::critical("physfs: mount {} failed: {}", gamepath.string(), physfs::last_error());
         std::terminate();
     }
 
     if(!PHYSFS_mount(userpath.string().c_str(), nullptr, false)) {
-        spdlog::critical("physfs: mount {} failed: {}", userpath.string(), physfs_error());
+        spdlog::critical("physfs: mount {} failed: {}", userpath.string(), physfs::last_error());
         std::terminate();
     }
 
     if(!PHYSFS_setWriteDir(userpath.string().c_str())) {
-        spdlog::critical("physfs: setwritedir {} failed: {}", userpath.string(), physfs_error());
+        spdlog::critical("physfs: setwritedir {} failed: {}", userpath.string(), physfs::last_error());
         std::terminate();
     }
 
@@ -121,7 +126,7 @@ void shared_game::shutdown(void)
     enet_deinitialize();
 
     if(!PHYSFS_deinit()) {
-        spdlog::critical("physfs: deinit failed: {}", physfs_error());
+        spdlog::critical("physfs: deinit failed: {}", physfs::last_error());
         std::terminate();
     }
 }
diff --git a/src/game/shared/game.hh b/src/game/shared/game.hh
index 6e89a3c..8fe3c90 100644
--- a/src/game/shared/game.hh
+++ b/src/game/shared/game.hh
@@ -1,3 +1,10 @@
+// SPDX-License-Identifier: BSD-2-Clause
+// Copyright (c) 2025 Kirill Dmitrievich
+// File: game.hh
+// Description: Shared initialization logic
+
+#ifndef SHARED_GAME_HH
+#define SHARED_GAME_HH
 #pragma once
 
 namespace shared_game
@@ -5,3 +12,5 @@ namespace shared_game
 void init(int argc, char** argv, std::string_view logfile = {});
 void shutdown(void);
 } // namespace shared_game
+
+#endif
diff --git a/src/game/shared/game_items.cc b/src/game/shared/game_items.cc
index 73f7cef..5fe8ba3 100644
--- a/src/game/shared/game_items.cc
+++ b/src/game/shared/game_items.cc
@@ -1,3 +1,8 @@
+// SPDX-License-Identifier: BSD-2-Clause
+// Copyright (c) 2025 Kirill Dmitrievich
+// File: game_items.cc
+// Description: All the items in the game
+
 #include "shared/pch.hh"
 
 #include "shared/game_items.hh"
diff --git a/src/game/shared/game_items.hh b/src/game/shared/game_items.hh
index 1170543..9901e18 100644
--- a/src/game/shared/game_items.hh
+++ b/src/game/shared/game_items.hh
@@ -1,3 +1,10 @@
+// SPDX-License-Identifier: BSD-2-Clause
+// Copyright (c) 2025 Kirill Dmitrievich
+// File: game_items.hh
+// Description: All the items in the game
+
+#ifndef SHARED_GAME_ITEMS_HH
+#define SHARED_GAME_ITEMS_HH
 #pragma once
 
 class Item;
@@ -19,3 +26,5 @@ namespace game_items
 {
 void populate(void);
 } // namespace game_items
+
+#endif
diff --git a/src/game/shared/game_voxels.cc b/src/game/shared/game_voxels.cc
index 010053a..6682dd8 100644
--- a/src/game/shared/game_voxels.cc
+++ b/src/game/shared/game_voxels.cc
@@ -1,3 +1,8 @@
+// SPDX-License-Identifier: BSD-2-Clause
+// Copyright (c) 2025 Kirill Dmitrievich
+// File: game_voxels.cc
+// Description: All the voxels in the game
+
 #include "shared/pch.hh"
 
 #include "shared/game_voxels.hh"
diff --git a/src/game/shared/game_voxels.hh b/src/game/shared/game_voxels.hh
index f46385c..403ee86 100644
--- a/src/game/shared/game_voxels.hh
+++ b/src/game/shared/game_voxels.hh
@@ -1,3 +1,10 @@
+// SPDX-License-Identifier: BSD-2-Clause
+// Copyright (c) 2025 Kirill Dmitrievich
+// File: game_voxels.hh
+// Description: All the voxels in the game
+
+#ifndef SHARED_GAME_VOXELS_HH
+#define SHARED_GAME_VOXELS_HH
 #pragma once
 
 class Voxel;
@@ -21,3 +28,5 @@ namespace game_voxels
 {
 void populate(void);
 } // namespace game_voxels
+
+#endif
diff --git a/src/game/shared/globals.cc b/src/game/shared/globals.cc
index 8552214..92da492 100644
--- a/src/game/shared/globals.cc
+++ b/src/game/shared/globals.cc
@@ -1,3 +1,8 @@
+// SPDX-License-Identifier: BSD-2-Clause
+// Copyright (c) 2025 Kirill Dmitrievich
+// File: globals.cc
+// Description: Global variables
+
 #include "shared/pch.hh"
 
 #include "shared/globals.hh"
diff --git a/src/game/shared/globals.hh b/src/game/shared/globals.hh
index 39a12a7..4c02f43 100644
--- a/src/game/shared/globals.hh
+++ b/src/game/shared/globals.hh
@@ -1,3 +1,10 @@
+// SPDX-License-Identifier: BSD-2-Clause
+// Copyright (c) 2025 Kirill Dmitrievich
+// File: globals.hh
+// Description: Global variables
+
+#ifndef SHARED_GLOBALS_HH
+#define SHARED_GLOBALS_HH
 #pragma once
 
 namespace globals
@@ -17,3 +24,5 @@ namespace globals
 {
 extern std::uint64_t curtime;
 } // namespace globals
+
+#endif
diff --git a/src/game/shared/pch.hh b/src/game/shared/pch.hh
index e978e0f..13afb80 100644
--- a/src/game/shared/pch.hh
+++ b/src/game/shared/pch.hh
@@ -1,3 +1,10 @@
+// SPDX-License-Identifier: BSD-2-Clause
+// Copyright (c) 2025 Kirill Dmitrievich
+// File: pch.hh
+// Description: Precompiled header
+
+#ifndef SHARED_PCH_HH
+#define SHARED_PCH_HH
 #pragma once
 
 #include <core/pch.hh> // inherit dependent includes from core.lib
@@ -17,3 +24,5 @@
 
 #include <spdlog/sinks/basic_file_sink.h>
 #include <spdlog/sinks/stdout_color_sinks.h>
+
+#endif
diff --git a/src/game/shared/protocol.cc b/src/game/shared/protocol.cc
index d274955..9b18f8a 100644
--- a/src/game/shared/protocol.cc
+++ b/src/game/shared/protocol.cc
@@ -1,3 +1,8 @@
+// SPDX-License-Identifier: BSD-2-Clause
+// Copyright (c) 2025 Kirill Dmitrievich
+// File: protocol.cc
+// Description: Network protocol on top of ENet
+
 #include "shared/pch.hh"
 
 #include "shared/protocol.hh"
diff --git a/src/game/shared/protocol.hh b/src/game/shared/protocol.hh
index 2582406..46e0202 100644
--- a/src/game/shared/protocol.hh
+++ b/src/game/shared/protocol.hh
@@ -1,3 +1,10 @@
+// SPDX-License-Identifier: BSD-2-Clause
+// Copyright (c) 2025 Kirill Dmitrievich
+// File: protocol.hh
+// Description: Network protocol on top of ENet
+
+#ifndef SHARED_PROTOCOL_HH
+#define SHARED_PROTOCOL_HH
 #pragma once
 
 #include "shared/world/chunk.hh"
@@ -210,3 +217,5 @@ struct protocol::DimensionInfo final : public protocol::Base<0x0012> {
     std::string name;
     float gravity;
 };
+
+#endif
diff --git a/src/game/shared/splash.cc b/src/game/shared/splash.cc
index 86ed0d0..86b71bc 100644
--- a/src/game/shared/splash.cc
+++ b/src/game/shared/splash.cc
@@ -1,3 +1,8 @@
+// SPDX-License-Identifier: BSD-2-Clause
+// Copyright (c) 2025 Kirill Dmitrievich
+// File: splash.cc
+// Description: Randomized text messages
+
 #include "shared/pch.hh"
 
 #include "shared/splash.hh"
@@ -39,7 +44,7 @@ static void splash_init_filename(std::string_view filename)
         splash_random.seed(std::random_device()());
     }
     else {
-        splash_lines.push_back(std::format("{}: {}", filename, physfs_error()));
+        splash_lines.push_back(std::format("{}: {}", filename, physfs::last_error()));
         splash_random.seed(std::random_device()());
     }
 }
diff --git a/src/game/shared/splash.hh b/src/game/shared/splash.hh
index be80cd6..0acfe3b 100644
--- a/src/game/shared/splash.hh
+++ b/src/game/shared/splash.hh
@@ -1,3 +1,10 @@
+// SPDX-License-Identifier: BSD-2-Clause
+// Copyright (c) 2025 Kirill Dmitrievich
+// File: splash.hh
+// Description: Randomized text messages
+
+#ifndef SHARED_SPLASH_HH
+#define SHARED_SPLASH_HH
 #pragma once
 
 namespace splash
@@ -6,3 +13,5 @@ void init_client(void);
 void init_server(void);
 std::string_view get(void);
 } // namespace splash
+
+#endif
diff --git a/src/game/shared/types.hh b/src/game/shared/types.hh
index 792ed0f..801206c 100644
--- a/src/game/shared/types.hh
+++ b/src/game/shared/types.hh
@@ -1,3 +1,10 @@
+// SPDX-License-Identifier: BSD-2-Clause
+// Copyright (c) 2025 Kirill Dmitrievich
+// File: types.hh
+// Description: Type definitions
+
+#ifndef SHARED_TYPES_HH
+#define SHARED_TYPES_HH
 #pragma once
 
 using item_id = std::uint32_t;
@@ -38,3 +45,5 @@ struct std::hash<chunk_pos_xz> final {
         return value;
     }
 };
+
+#endif
diff --git a/src/game/shared/world/chunk.cc b/src/game/shared/world/chunk.cc
index 10da80e..2840fc1 100644
--- a/src/game/shared/world/chunk.cc
+++ b/src/game/shared/world/chunk.cc
@@ -1,3 +1,8 @@
+// SPDX-License-Identifier: BSD-2-Clause
+// Copyright (c) 2025 Kirill Dmitrievich
+// File: chunk.cc
+// Description: A single chunk of voxels
+
 #include "shared/pch.hh"
 
 #include "shared/world/chunk.hh"
diff --git a/src/game/shared/world/chunk.hh b/src/game/shared/world/chunk.hh
index f8e38b4..b0b0604 100644
--- a/src/game/shared/world/chunk.hh
+++ b/src/game/shared/world/chunk.hh
@@ -1,3 +1,10 @@
+// SPDX-License-Identifier: BSD-2-Clause
+// Copyright (c) 2025 Kirill Dmitrievich
+// File: chunk.hh
+// Description: A single chunk of voxels
+
+#ifndef SHARED_WORLD_CHUNK_HH
+#define SHARED_WORLD_CHUNK_HH
 #pragma once
 
 #include "shared/world/voxel_storage.hh"
@@ -35,3 +42,5 @@ private:
     VoxelStorage m_voxels;
     unsigned int m_biome;
 };
+
+#endif
diff --git a/src/game/shared/world/chunk_aabb.hh b/src/game/shared/world/chunk_aabb.hh
index 0f8851c..7cf042c 100644
--- a/src/game/shared/world/chunk_aabb.hh
+++ b/src/game/shared/world/chunk_aabb.hh
@@ -1,3 +1,10 @@
+// SPDX-License-Identifier: BSD-2-Clause
+// Copyright (c) 2025 Kirill Dmitrievich
+// File: chunk_aabb.hh
+// Description: Axis-aligned bounding box for chunk-domain coordinates
+
+#ifndef SHARED_WORLD_CHUNK_AABB_HH
+#define SHARED_WORLD_CHUNK_AABB_HH
 #pragma once
 
 #include "core/math/aabb.hh"
@@ -5,3 +12,5 @@
 #include "shared/types.hh"
 
 using ChunkAABB = math::AABB<chunk_pos::value_type>;
+
+#endif
diff --git a/src/game/shared/world/dimension.cc b/src/game/shared/world/dimension.cc
index 84ca539..393aa0c 100644
--- a/src/game/shared/world/dimension.cc
+++ b/src/game/shared/world/dimension.cc
@@ -1,3 +1,8 @@
+// SPDX-License-Identifier: BSD-2-Clause
+// Copyright (c) 2025 Kirill Dmitrievich
+// File: dimension.cc
+// Description: A single world
+
 #include "shared/pch.hh"
 
 #include "shared/world/dimension.hh"
diff --git a/src/game/shared/world/dimension.hh b/src/game/shared/world/dimension.hh
index b57640a..9845c5a 100644
--- a/src/game/shared/world/dimension.hh
+++ b/src/game/shared/world/dimension.hh
@@ -1,3 +1,10 @@
+// SPDX-License-Identifier: BSD-2-Clause
+// Copyright (c) 2025 Kirill Dmitrievich
+// File: dimension.hh
+// Description: A single world
+
+#ifndef SHARED_WORLD_DIMENSION_HH
+#define SHARED_WORLD_DIMENSION_HH
 #pragma once
 
 #include "shared/const.hh"
@@ -81,3 +88,5 @@ struct VoxelSetEvent final {
     local_pos lpos;
     Chunk* chunk;
 };
+
+#endif
diff --git a/src/game/shared/world/feature.cc b/src/game/shared/world/feature.cc
index 3974082..1226b1f 100644
--- a/src/game/shared/world/feature.cc
+++ b/src/game/shared/world/feature.cc
@@ -1,3 +1,8 @@
+// SPDX-License-Identifier: BSD-2-Clause
+// Copyright (c) 2025 Kirill Dmitrievich
+// File: feature.cc
+// Description: A world generation feature
+
 #include "shared/pch.hh"
 
 #include "shared/world/feature.hh"
diff --git a/src/game/shared/world/feature.hh b/src/game/shared/world/feature.hh
index b80869d..820ddc7 100644
--- a/src/game/shared/world/feature.hh
+++ b/src/game/shared/world/feature.hh
@@ -1,3 +1,10 @@
+// SPDX-License-Identifier: BSD-2-Clause
+// Copyright (c) 2025 Kirill Dmitrievich
+// File: feature.hh
+// Description: A world generation feature
+
+#ifndef SHARED_WORLD_FEATURE_HH
+#define SHARED_WORLD_FEATURE_HH
 #pragma once
 
 #include "shared/types.hh"
@@ -17,3 +24,5 @@ public:
     void place(const voxel_pos& vpos, const chunk_pos& cpos, Chunk& chunk) const;
     void place(const voxel_pos& vpos, const chunk_pos& cpos, VoxelStorage& voxels) const;
 };
+
+#endif
diff --git a/src/game/shared/world/item.cc b/src/game/shared/world/item.cc
index bc1546a..207e9da 100644
--- a/src/game/shared/world/item.cc
+++ b/src/game/shared/world/item.cc
@@ -1,3 +1,8 @@
+// SPDX-License-Identifier: BSD-2-Clause
+// Copyright (c) 2025 Kirill Dmitrievich
+// File: item.cc
+// Description: Item metadata
+
 #include "shared/pch.hh"
 
 #include "shared/world/item.hh"
diff --git a/src/game/shared/world/item.hh b/src/game/shared/world/item.hh
index bcec37a..3786b19 100644
--- a/src/game/shared/world/item.hh
+++ b/src/game/shared/world/item.hh
@@ -1,3 +1,10 @@
+// SPDX-License-Identifier: BSD-2-Clause
+// Copyright (c) 2025 Kirill Dmitrievich
+// File: item.hh
+// Description: Item metadata
+
+#ifndef SHARED_WORLD_ITEM_HH
+#define SHARED_WORLD_ITEM_HH
 #pragma once
 
 #include "core/resource/resource.hh"
@@ -73,3 +80,5 @@ constexpr resource_ptr<TextureGUI>& Item::get_cached_texture(void) const noexcep
 {
     return m_cached_texture;
 }
+
+#endif
diff --git a/src/game/shared/world/item_registry.cc b/src/game/shared/world/item_registry.cc
index c7d8d9b..6f5a8a0 100644
--- a/src/game/shared/world/item_registry.cc
+++ b/src/game/shared/world/item_registry.cc
@@ -1,3 +1,8 @@
+// SPDX-License-Identifier: BSD-2-Clause
+// Copyright (c) 2025 Kirill Dmitrievich
+// File: item_registry.cc
+// Description: Registry for all the items in the game
+
 #include "shared/pch.hh"
 
 #include "shared/world/item_registry.hh"
diff --git a/src/game/shared/world/item_registry.hh b/src/game/shared/world/item_registry.hh
index f8fe641..588211d 100644
--- a/src/game/shared/world/item_registry.hh
+++ b/src/game/shared/world/item_registry.hh
@@ -1,3 +1,10 @@
+// SPDX-License-Identifier: BSD-2-Clause
+// Copyright (c) 2025 Kirill Dmitrievich
+// File: item_registry.hh
+// Description: Registry for all the items in the game
+
+#ifndef SHARED_WORLD_ITEM_REGISTRY_HH
+#define SHARED_WORLD_ITEM_REGISTRY_HH
 #pragma once
 
 #include "shared/world/item.hh"
@@ -24,3 +31,5 @@ namespace item_registry
 {
 std::uint64_t get_checksum(void);
 } // namespace item_registry
+
+#endif
diff --git a/src/game/shared/world/ray_aabb.cc b/src/game/shared/world/ray_aabb.cc
index f6f2638..9bc2ee0 100644
--- a/src/game/shared/world/ray_aabb.cc
+++ b/src/game/shared/world/ray_aabb.cc
@@ -1,3 +1,8 @@
+// SPDX-License-Identifier: BSD-2-Clause
+// Copyright (c) 2025 Kirill Dmitrievich
+// File: ray_aabb.cc
+// Description: Check ray intersections against an AABB
+
 #include "shared/pch.hh"
 
 #include "shared/world/ray_aabb.hh"
diff --git a/src/game/shared/world/ray_aabb.hh b/src/game/shared/world/ray_aabb.hh
index 49c0846..640a02c 100644
--- a/src/game/shared/world/ray_aabb.hh
+++ b/src/game/shared/world/ray_aabb.hh
@@ -1,3 +1,10 @@
+// SPDX-License-Identifier: BSD-2-Clause
+// Copyright (c) 2025 Kirill Dmitrievich
+// File: ray_aabb.hh
+// Description: Check ray intersections against an AABB
+
+#ifndef SHARED_WORLD_RAY_AABB_HH
+#define SHARED_WORLD_RAY_AABB_HH
 #pragma once
 
 #include "core/math/aabb.hh"
@@ -28,3 +35,5 @@ constexpr const glm::fvec3& RayAABB::direction(void) const noexcept
 {
     return m_direction;
 }
+
+#endif
diff --git a/src/game/shared/world/ray_dda.cc b/src/game/shared/world/ray_dda.cc
index 5dbf82e..45480b8 100644
--- a/src/game/shared/world/ray_dda.cc
+++ b/src/game/shared/world/ray_dda.cc
@@ -1,3 +1,8 @@
+// SPDX-License-Identifier: BSD-2-Clause
+// Copyright (c) 2025 Kirill Dmitrievich
+// File: ray_dda.cc
+// Description: Fast voxel grid traversal with an arbitrary starting position
+
 #include "shared/pch.hh"
 
 #include "shared/world/ray_dda.hh"
diff --git a/src/game/shared/world/ray_dda.hh b/src/game/shared/world/ray_dda.hh
index 72f746e..c3cbb09 100644
--- a/src/game/shared/world/ray_dda.hh
+++ b/src/game/shared/world/ray_dda.hh
@@ -1,3 +1,10 @@
+// SPDX-License-Identifier: BSD-2-Clause
+// Copyright (c) 2025 Kirill Dmitrievich
+// File: ray_dda.hh
+// Description: Fast voxel grid traversal with an arbitrary starting position
+
+#ifndef SHARED_WORLD_RAY_DDA_HH
+#define SHARED_WORLD_RAY_DDA_HH
 #pragma once
 
 #include "shared/types.hh"
@@ -30,3 +37,5 @@ public:
     voxel_pos vnormal;
     voxel_pos vpos;
 };
+
+#endif
diff --git a/src/game/shared/world/voxel.cc b/src/game/shared/world/voxel.cc
index 4f47c2d..71ef7b8 100644
--- a/src/game/shared/world/voxel.cc
+++ b/src/game/shared/world/voxel.cc
@@ -1,3 +1,8 @@
+// SPDX-License-Identifier: BSD-2-Clause
+// Copyright (c) 2025 Kirill Dmitrievich
+// File: voxel.cc
+// Description: Voxel metadata... A metavoxel!
+
 #include "shared/pch.hh"
 
 #include "shared/world/voxel.hh"
diff --git a/src/game/shared/world/voxel.hh b/src/game/shared/world/voxel.hh
index 0a8c4a3..8f6e344 100644
--- a/src/game/shared/world/voxel.hh
+++ b/src/game/shared/world/voxel.hh
@@ -1,3 +1,10 @@
+// SPDX-License-Identifier: BSD-2-Clause
+// Copyright (c) 2025 Kirill Dmitrievich
+// File: voxel.hh
+// Description: Voxel metadata... A metavoxel!
+
+#ifndef SHARED_WORLD_VOXEL_HH
+#define SHARED_WORLD_VOXEL_HH
 #pragma once
 
 #include "core/math/aabb.hh"
@@ -269,3 +276,5 @@ constexpr bool Voxel::is_surface_material(void) const noexcept
 {
     return m_surface_material == Material;
 }
+
+#endif
diff --git a/src/game/shared/world/voxel_registry.cc b/src/game/shared/world/voxel_registry.cc
index f950a4d..530b100 100644
--- a/src/game/shared/world/voxel_registry.cc
+++ b/src/game/shared/world/voxel_registry.cc
@@ -1,3 +1,8 @@
+// SPDX-License-Identifier: BSD-2-Clause
+// Copyright (c) 2025 Kirill Dmitrievich
+// File: voxel_registry.cc
+// Description: Registry for all the voxels in the game
+
 #include "shared/pch.hh"
 
 #include "shared/world/voxel_registry.hh"
diff --git a/src/game/shared/world/voxel_registry.hh b/src/game/shared/world/voxel_registry.hh
index 5dbaf50..4e60808 100644
--- a/src/game/shared/world/voxel_registry.hh
+++ b/src/game/shared/world/voxel_registry.hh
@@ -1,3 +1,10 @@
+// SPDX-License-Identifier: BSD-2-Clause
+// Copyright (c) 2025 Kirill Dmitrievich
+// File: voxel_registry.hh
+// Description: Registry for all the voxels in the game
+
+#ifndef SHARED_WORLD_VOXEL_REGISTRY_HH
+#define SHARED_WORLD_VOXEL_REGISTRY_HH
 #pragma once
 
 #include "shared/world/voxel.hh"
@@ -24,3 +31,5 @@ namespace voxel_registry
 {
 std::uint64_t get_checksum(void);
 } // namespace voxel_registry
+
+#endif
diff --git a/src/game/shared/world/voxel_storage.cc b/src/game/shared/world/voxel_storage.cc
index 43ca116..7890894 100644
--- a/src/game/shared/world/voxel_storage.cc
+++ b/src/game/shared/world/voxel_storage.cc
@@ -1,3 +1,8 @@
+// SPDX-License-Identifier: BSD-2-Clause
+// Copyright (c) 2025 Kirill Dmitrievich
+// File: voxel_storage.cc
+// Description: Storage for voxels in a chunk
+
 #include "shared/pch.hh"
 
 #include "shared/world/voxel_storage.hh"
diff --git a/src/game/shared/world/voxel_storage.hh b/src/game/shared/world/voxel_storage.hh
index ef427b3..e3d149a 100644
--- a/src/game/shared/world/voxel_storage.hh
+++ b/src/game/shared/world/voxel_storage.hh
@@ -1,3 +1,10 @@
+// SPDX-License-Identifier: BSD-2-Clause
+// Copyright (c) 2025 Kirill Dmitrievich
+// File: voxel_storage.hh
+// Description: Storage for voxels in a chunk
+
+#ifndef SHARED_WORLD_VOXEL_STORAGE_HH
+#define SHARED_WORLD_VOXEL_STORAGE_HH
 #pragma once
 
 #include "shared/const.hh"
@@ -12,3 +19,5 @@ public:
     void serialize(WriteBuffer& buffer) const;
     void deserialize(ReadBuffer& buffer);
 };
+
+#endif