diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 24e23a1..cafc3d0 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -184,6 +184,7 @@ jobs:
         uses: actions/checkout@v7
         with:
           path: SleakCraft
+          fetch-depth: 0
 
       - name: Check out the engine
         uses: actions/checkout@v7
@@ -192,8 +193,10 @@ jobs:
           ref: ${{ needs.engine-ref.outputs.ref }}
           path: SleakCraft/Engine
 
-      - name: Install glslc
-        run: sudo apt-get update && sudo apt-get install -y glslc
+      - name: Install shader tools
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y glslc glslang-tools
 
       # Byte comparison against the committed .spv is not usable here: glslc
       # embeds its own generator version, so a different toolchain produces
@@ -206,7 +209,8 @@ jobs:
           for src in *.vert *.frag; do
             [ -e "$src" ] || continue
             case "$src" in *_gl.vert|*_gl.frag) continue ;; esac
-            if ! glslc "$src" -o /tmp/out.spv; then
+            if ! glslc -I ../../../Engine/assets/shaders/include -I include \
+                 "$src" -o /tmp/out.spv; then
               echo "FAILED to compile: $src"
               fail=1
             fi
@@ -228,6 +232,71 @@ jobs:
           [ $missing -eq 0 ] && echo "All voxel shaders have committed SPIR-V."
           exit $missing
 
+      # Committed .spv are compiled against the engine the game pins, so a
+      # change to a game shader, a game include, or an engine include between
+      # the base and head pins needs fresh SPIR-V.
+      - name: Edited GLSL and engine includes come with SPIR-V
+        working-directory: SleakCraft
+        env:
+          BASE: ${{ github.event_name == 'pull_request' && format('origin/{0}', github.base_ref) || github.event.before }}
+        run: |
+          if [ ! -f Engine/scripts/check_spirv_fresh.py ]; then
+            echo "::warning::The engine has no scripts/check_spirv_fresh.py."
+            exit 0
+          fi
+          if [ "${{ github.event_name }}" = "pull_request" ]; then
+            git fetch --no-tags origin "${{ github.base_ref }}"
+          fi
+          if ! git cat-file -e "$BASE^{commit}" 2>/dev/null; then
+            echo "No base commit to compare against."
+            exit 0
+          fi
+          BASE=$(git merge-base "$BASE" HEAD)
+          old_pin=$(git rev-parse "$BASE:Engine")
+          new_pin=$(git rev-parse "HEAD:Engine")
+          for tree in base head; do
+            mkdir -p "/tmp/$tree/Engine/assets/shaders"
+            cp -r Engine/assets/shaders/include "/tmp/$tree/Engine/assets/shaders/" 2>/dev/null || true
+          done
+          git archive "$BASE" Game/assets/shaders | tar -x -C /tmp/base
+          git archive HEAD Game/assets/shaders | tar -x -C /tmp/head
+          git diff --name-only "$BASE" HEAD -- Game/assets/shaders > /tmp/changed.txt
+          if git -C Engine fetch --no-tags --depth=1 origin "$old_pin" "$new_pin"; then
+            for pair in "base:$old_pin" "head:$new_pin"; do
+              tree=${pair%%:*}
+              pin=${pair#*:}
+              rm -rf "/tmp/$tree/Engine/assets/shaders/include"
+              if git -C Engine cat-file -e "$pin:assets/shaders/include" 2>/dev/null; then
+                git -C Engine archive "$pin" assets/shaders/include | tar -x -C "/tmp/$tree/Engine"
+              fi
+            done
+            git -C Engine diff --name-only "$old_pin" "$new_pin" -- assets/shaders/include \
+              | sed 's|^|Engine/|' >> /tmp/changed.txt
+          else
+            echo "::warning::Engine pins are not on the remote, engine include changes are not checked."
+          fi
+          python3 Engine/scripts/check_spirv_fresh.py --base /tmp/base --head /tmp/head \
+            --shaders Game/assets/shaders \
+            --include Engine/assets/shaders/include \
+            --include Game/assets/shaders/include \
+            --changed /tmp/changed.txt
+
+      - name: Every OpenGL shader validates
+        working-directory: SleakCraft/Game/assets/shaders
+        run: |
+          fail=0
+          for src in *_gl.vert *_gl.frag; do
+            [ -e "$src" ] || continue
+            out="/tmp/gl_expanded.${src##*.}"
+            if ! glslangValidator -E -I../../../Engine/assets/shaders/include \
+                   -Iinclude "$src" > "$out" ||
+               ! glslangValidator "$out"; then
+              echo "FAILED to validate: $src"
+              fail=1
+            fi
+          done
+          exit $fail
+
   # Compiling proves nothing about whether the game runs. Runners have no GPU,
   # but Mesa's software Vulkan (lavapipe) plus a virtual display is enough to
   # boot the real binary into a real world and catch startup crashes, missing
@@ -323,6 +392,10 @@ jobs:
             echo "A crash signature appeared in the output."
             exit 1
           fi
+          if grep -qE "Shader compilation failed|Shader program linking failed|Cannot read shader" smoke.log; then
+            echo "An OpenGL shader failed to build."
+            exit 1
+          fi
           echo "Booted into a world and survived the run window."
 
       - name: Upload the smoke log
diff --git a/Client/CMakeLists.txt b/Client/CMakeLists.txt
index 1d9ac50..179816e 100644
--- a/Client/CMakeLists.txt
+++ b/Client/CMakeLists.txt
@@ -22,12 +22,17 @@ set(_asset_out_dir "${CMAKE_RUNTIME_OUTPUT_DIRECTORY}/assets")
 
 set(_sleak_seen_outputs "")
 
+# Optional third argument: subfolder of bin/assets to copy into
 function(sleak_track_asset_dir SRC_DIR LABEL)
+    set(_dst_root "${_asset_out_dir}")
+    if(ARGC GREATER 2)
+        set(_dst_root "${_asset_out_dir}/${ARGV2}")
+    endif()
     file(GLOB_RECURSE _files CONFIGURE_DEPENDS "${SRC_DIR}/*")
     set(_outputs "")
     foreach(_src ${_files})
         file(RELATIVE_PATH _rel "${SRC_DIR}" "${_src}")
-        set(_dst "${_asset_out_dir}/${_rel}")
+        set(_dst "${_dst_root}/${_rel}")
         list(FIND _sleak_seen_outputs "${_dst}" _seen_idx)
         if(NOT _seen_idx EQUAL -1)
             continue()
@@ -47,10 +52,29 @@ function(sleak_track_asset_dir SRC_DIR LABEL)
 endfunction()
 
 set(SLEAK_ASSET_OUTPUTS "")
+# Built game SPIR-V wins over the committed copies
+get_property(_game_spirv GLOBAL PROPERTY GAME_SPIRV_FILES)
+foreach(_spv ${_game_spirv})
+    get_filename_component(_name "${_spv}" NAME)
+    set(_dst "${_asset_out_dir}/shaders/${_name}")
+    add_custom_command(
+        OUTPUT "${_dst}"
+        COMMAND ${CMAKE_COMMAND} -E copy_if_different "${_spv}" "${_dst}"
+        DEPENDS "${_spv}"
+        COMMENT "Copy game SPIR-V: ${_name}"
+        VERBATIM
+    )
+    list(APPEND SLEAK_ASSET_OUTPUTS "${_dst}")
+    list(APPEND _sleak_seen_outputs "${_dst}")
+endforeach()
+# Include libraries resolve engine first, as glslc -I does
+sleak_track_asset_dir("${CMAKE_SOURCE_DIR}/Engine/assets/shaders/include"
+                      "engine" "shaders/include")
 sleak_track_asset_dir("${CMAKE_SOURCE_DIR}/Game/assets"          "game")
 sleak_track_asset_dir("${CMAKE_SOURCE_DIR}/Engine/assets" "engine")
 
 add_custom_target(CopyAssets ALL DEPENDS ${SLEAK_ASSET_OUTPUTS})
+add_dependencies(CopyAssets GameShaders)
 add_dependencies(SleakCraft CopyAssets)
 
 # --- Post-build: copy runtime DLLs (Windows) ---
diff --git a/Client/src/main.cpp b/Client/src/main.cpp
index 4ec10c3..29f2f37 100644
--- a/Client/src/main.cpp
+++ b/Client/src/main.cpp
@@ -23,9 +23,11 @@ static void PrintHelp(const char* exe) {
         << "  -t <name>          Window title        (use _ for spaces)\n"
         << "  --fullscreen       Start in fullscreen\n"
         << "\nWorld\n"
-        << "  -world <name>      Load world if save exists, create new otherwise\n"
+        << "  -world <name>      Load world if save exists, create new "
+           "otherwise\n"
         << "  -seed <n>          Seed for new world (default: random)\n"
-        << "  -rd <n>            Initial render distance in chunks (default: 8)\n"
+        << "  -rd <n>            Initial render distance in chunks (default: "
+           "8)\n"
         << "\nGraphics\n"
         << "  -msaa <n>          MSAA sample count: 1, 2, 4, 8\n"
         << "  --vsync            Enable VSync on launch\n"
@@ -37,7 +39,8 @@ static void PrintHelp(const char* exe) {
         << "  -campose x,y,z,yaw,pitch\n"
         << "                     Pin the camera, degrees (Debug or --bench)\n"
         << "  --gpuprofile       Log per-pass GPU timings (Vulkan)\n"
-        << "  -capture <file>    Write frame N as a PPM, then exit (Vulkan)\n"
+        << "  -capture <file>    Write frame N as a PPM, then exit (Vulkan, "
+           "OpenGL)\n"
         << "  -capture-frame <n> Frame index for -capture (default: 600)\n"
         << "\nDebug\n"
         << "  --validate         Enable Vulkan validation (Debug: always on)\n"
diff --git a/Engine b/Engine
index d319e9e..a393409 160000
--- a/Engine
+++ b/Engine
@@ -1 +1 @@
-Subproject commit d319e9e2dba42e0753efa4bc29625a27a18a6e57
+Subproject commit a393409321b5138653632927c1656297f6899f07
diff --git a/Game/CMakeLists.txt b/Game/CMakeLists.txt
index f547fbb..a232e28 100644
--- a/Game/CMakeLists.txt
+++ b/Game/CMakeLists.txt
@@ -14,3 +14,58 @@ target_include_directories(SleakGame PUBLIC
                           ${CMAKE_CURRENT_SOURCE_DIR}/include)
 
 target_link_libraries(SleakGame PRIVATE Engine)
+
+# --- SPIR-V shaders (committed .spv are only the fallback without glslc) ---
+set(GAME_SHADER_DIR "${CMAKE_CURRENT_SOURCE_DIR}/assets/shaders")
+set(GAME_SHADER_INCLUDE_DIR "${GAME_SHADER_DIR}/include")
+# sleak/ is the engine's include namespace
+if(EXISTS "${GAME_SHADER_INCLUDE_DIR}/sleak")
+    message(FATAL_ERROR
+        "${GAME_SHADER_INCLUDE_DIR}/sleak would shadow the engine include "
+        "library. Put game includes in include/craft/ instead.")
+endif()
+file(GLOB GAME_VULKAN_SHADERS CONFIGURE_DEPENDS
+    "${GAME_SHADER_DIR}/*.vert"
+    "${GAME_SHADER_DIR}/*.frag"
+)
+list(FILTER GAME_VULKAN_SHADERS EXCLUDE REGEX "_gl\\.(vert|frag)$")
+file(GLOB_RECURSE GAME_SHADER_INCLUDES CONFIGURE_DEPENDS
+    "${GAME_SHADER_INCLUDE_DIR}/*.glsl")
+# Engine include edits must rebuild game SPIR-V too
+get_property(_engine_include_dir GLOBAL PROPERTY ENGINE_SHADER_INCLUDE_DIR)
+get_property(_engine_includes GLOBAL PROPERTY ENGINE_SHADER_INCLUDES)
+if(NOT _engine_include_dir)
+    set(_engine_include_dir "${CMAKE_SOURCE_DIR}/Engine/assets/shaders/include")
+endif()
+
+find_program(GLSLC glslc
+    HINTS "$ENV{VULKAN_SDK}/Bin" "$ENV{VULKAN_SDK}/bin" "${VULKAN_SDK}/Bin")
+set(GAME_SPIRV_FILES "")
+if(GLSLC)
+    set(_spirv_dir "${CMAKE_CURRENT_BINARY_DIR}/shaders")
+    file(MAKE_DIRECTORY "${_spirv_dir}")
+    foreach(_src ${GAME_VULKAN_SHADERS})
+        get_filename_component(_name "${_src}" NAME)
+        set(_spv "${_spirv_dir}/${_name}.spv")
+        add_custom_command(
+            OUTPUT "${_spv}"
+            COMMAND ${GLSLC} -I "${_engine_include_dir}"
+                    -I "${GAME_SHADER_INCLUDE_DIR}" "${_src}" -o "${_spv}"
+            DEPENDS "${_src}" ${_engine_includes} ${GAME_SHADER_INCLUDES}
+            COMMENT "Compiling ${_name} to SPIR-V"
+            VERBATIM
+        )
+        list(APPEND GAME_SPIRV_FILES "${_spv}")
+    endforeach()
+else()
+    foreach(_src ${GAME_VULKAN_SHADERS})
+        if(NOT EXISTS "${_src}.spv")
+            message(FATAL_ERROR
+                "glslc not found and ${_src} has no committed SPIR-V. "
+                "Install the Vulkan SDK or set VULKAN_SDK.")
+        endif()
+    endforeach()
+endif()
+add_custom_target(GameShaders ALL DEPENDS ${GAME_SPIRV_FILES})
+# Client stages these over the committed copies
+set_property(GLOBAL PROPERTY GAME_SPIRV_FILES ${GAME_SPIRV_FILES})
diff --git a/Game/assets/shaders/flat_shader.frag b/Game/assets/shaders/flat_shader.frag
index 0e892f3..946920f 100644
--- a/Game/assets/shaders/flat_shader.frag
+++ b/Game/assets/shaders/flat_shader.frag
@@ -1,4 +1,5 @@
 #version 450
+#extension GL_GOOGLE_include_directive : require
 
 layout(location = 0) in vec3 fragWorldPos;
 layout(location = 1) in vec3 fragWorldNorm;
@@ -10,21 +11,8 @@ layout(location = 0) out vec4 outColor;
 
 layout(set = 0, binding = 0) uniform sampler2D diffuseTexture;
 
-layout(set = 2, binding = 0) uniform ShadowLightUBO {
-    vec4  uLightDir;
-    vec4  uLightColor;
-    vec4  uAmbient;        // rgb = sky ambient color, a = intensity
-    vec4  uCameraPos;
-    mat4  uLightVP;
-    float uShadowBias;
-    float uShadowStrength;
-    float uShadowTexelSize;
-    float uLightSize;
-    vec4  uFogColor;
-    float uFogStart;
-    float uFogEnd;
-    vec2  _fogPad;            // std140: must be vec2 (8B) not float[2] (stride-16 = 32B)
-};
+#include "sleak/shadow_light.glsl"
+#include "sleak/frame.glsl"
 
 layout(set = 3, binding = 0) uniform sampler2DShadow shadowMap;
 
@@ -120,5 +108,5 @@ void main() {
         lit = mix(uFogColor.rgb, lit, fogFactor);
     }
 
-    outColor = vec4(lit, texColor.a);
+    outColor = SleakFrameGuard(vec4(lit, texColor.a));
 }
diff --git a/Game/assets/shaders/flat_shader.frag.spv b/Game/assets/shaders/flat_shader.frag.spv
index 80e3efd..3bc97ba 100644
Binary files a/Game/assets/shaders/flat_shader.frag.spv and b/Game/assets/shaders/flat_shader.frag.spv differ
diff --git a/Game/assets/shaders/flat_shader.vert b/Game/assets/shaders/flat_shader.vert
index a05e82c..7becd59 100644
--- a/Game/assets/shaders/flat_shader.vert
+++ b/Game/assets/shaders/flat_shader.vert
@@ -1,4 +1,5 @@
 #version 450
+#extension GL_GOOGLE_include_directive : require
 
 layout(location = 0) in vec3 inPosition;
 layout(location = 1) in vec3 inNormal;
@@ -10,21 +11,7 @@ layout(push_constant) uniform TransformPC {
     mat4 World;
 };
 
-layout(set = 2, binding = 0) uniform ShadowLightUBO {
-    vec4  uLightDir;       // xyz = direction, w = pad
-    vec4  uLightColor;     // rgb = color, a = intensity
-    vec4  uAmbient;        // rgb = color, a = intensity
-    vec4  uCameraPos;      // xyz = camera world pos, w = pad
-    mat4  uLightVP;        // light view-projection matrix
-    float uShadowBias;
-    float uShadowStrength;
-    float uShadowTexelSize;
-    float uLightSize;
-    vec4  uFogColor;       // rgb + alpha
-    float uFogStart;       // distance where fog begins
-    float uFogEnd;         // distance where fog fully obscures
-    vec2  _fogPad;            // std140: must be vec2 (8B) not float[2] (stride-16 = 32B)
-};
+#include "sleak/shadow_light.glsl"
 
 layout(location = 0) out vec3 fragWorldPos;
 layout(location = 1) out vec3 fragWorldNorm;
diff --git a/Game/assets/shaders/flat_shader.vert.spv b/Game/assets/shaders/flat_shader.vert.spv
index 2e7ab08..8afedd6 100644
Binary files a/Game/assets/shaders/flat_shader.vert.spv and b/Game/assets/shaders/flat_shader.vert.spv differ
diff --git a/Game/assets/shaders/flat_shader_gl.frag b/Game/assets/shaders/flat_shader_gl.frag
index 7d9cd8b..60e7a45 100644
--- a/Game/assets/shaders/flat_shader_gl.frag
+++ b/Game/assets/shaders/flat_shader_gl.frag
@@ -1,4 +1,5 @@
 #version 450 core
+#extension GL_GOOGLE_include_directive : require
 
 in vec3 fragWorldPos;
 in vec3 fragWorldNorm;
@@ -39,6 +40,8 @@ layout(std140, binding = 5) uniform ShadowUBO {
     float _shadowPad0, _shadowPad1;
 };
 
+#include "sleak/frame.glsl"
+
 layout(binding = 0) uniform sampler2D diffuseTexture;
 layout(binding = 3) uniform sampler2DShadow shadowMap;
 
@@ -142,5 +145,5 @@ void main() {
         lit = mix(FogColor.rgb, lit, fogFactor);
     }
 
-    outColor = vec4(lit, texColor.a);
+    outColor = SleakFrameGuard(vec4(lit, texColor.a));
 }
diff --git a/Game/assets/shaders/flat_shader_gl.vert b/Game/assets/shaders/flat_shader_gl.vert
index 0111c70..bdcb5d2 100644
--- a/Game/assets/shaders/flat_shader_gl.vert
+++ b/Game/assets/shaders/flat_shader_gl.vert
@@ -1,4 +1,5 @@
 #version 450 core
+#extension GL_GOOGLE_include_directive : require
 
 layout(location = 0) in vec3 inPosition;
 layout(location = 1) in vec3 inNormal;
@@ -10,16 +11,8 @@ layout(std140, binding = 0) uniform TransformUBO {
     mat4 World;
 };
 
-layout(std140, binding = 5) uniform ShadowUBO {
-    mat4  ShadowLightVP;
-    float ShadowBias;
-    float ShadowStrength;
-    float ShadowTexelSize;
-    float ShadowLightSize;
-    uint  PCSSEnabled;
-    uint  ShadowMapEnabled;
-    float _shadowPad0, _shadowPad1;
-};
+#include "sleak/shadow_light.glsl"
+#include "sleak/frame.glsl"
 
 out vec3 fragWorldPos;
 out vec3 fragWorldNorm;
@@ -28,7 +21,7 @@ out vec2 fragUV;
 out vec4 fragShadowCoord;
 
 void main() {
-    gl_Position = WVP * vec4(inPosition, 1.0);
+    gl_Position = SleakFrameGuardClip(WVP * vec4(inPosition, 1.0));
 
     vec4 worldPos = World * vec4(inPosition, 1.0);
     fragWorldPos = worldPos.xyz;
@@ -39,5 +32,5 @@ void main() {
     fragColor = inColor;
     fragUV    = inUV;
 
-    fragShadowCoord = ShadowLightVP * worldPos;
+    fragShadowCoord = uLightVP * worldPos;
 }
diff --git a/Game/assets/shaders/gbuffer_gl.vert b/Game/assets/shaders/gbuffer_gl.vert
index bd9f5dc..085e5a7 100644
--- a/Game/assets/shaders/gbuffer_gl.vert
+++ b/Game/assets/shaders/gbuffer_gl.vert
@@ -1,4 +1,5 @@
 #version 450 core
+#extension GL_GOOGLE_include_directive : require
 
 layout(location = 0) in vec3 inPosition;
 layout(location = 1) in vec3 inNormal;
@@ -10,16 +11,8 @@ layout(std140, binding = 0) uniform TransformUBO {
     mat4 World;
 };
 
-layout(std140, binding = 5) uniform ShadowUBO {
-    mat4  ShadowLightVP;
-    float ShadowBias;
-    float ShadowStrength;
-    float ShadowTexelSize;
-    float ShadowLightSize;
-    uint  PCSSEnabled;
-    uint  ShadowMapEnabled;
-    float _shadowPad0, _shadowPad1;
-};
+#include "sleak/shadow_light.glsl"
+#include "sleak/frame.glsl"
 
 out vec3 fragWorldPos;
 out vec3 fragWorldNorm;
@@ -30,7 +23,7 @@ out vec2 fragUV;
 out vec4 fragShadowCoord;
 
 void main() {
-    gl_Position = WVP * vec4(inPosition, 1.0);
+    gl_Position = SleakFrameGuardClip(WVP * vec4(inPosition, 1.0));
 
     vec4 worldPos  = World * vec4(inPosition, 1.0);
     fragWorldPos   = worldPos.xyz;
@@ -48,5 +41,5 @@ void main() {
     fragWorldBit   = B;
     fragColor      = inColor;
     fragUV         = inUV;
-    fragShadowCoord = ShadowLightVP * worldPos;
+    fragShadowCoord = uLightVP * worldPos;
 }
diff --git a/Game/assets/shaders/gbuffer_voxel.vert b/Game/assets/shaders/gbuffer_voxel.vert
index 56f8574..bf93bb6 100644
--- a/Game/assets/shaders/gbuffer_voxel.vert
+++ b/Game/assets/shaders/gbuffer_voxel.vert
@@ -1,4 +1,5 @@
 #version 450
+#extension GL_GOOGLE_include_directive : require
 
 // ============================================================
 // GBuffer Geometry Pass - Voxel Vertex Shader
@@ -17,22 +18,8 @@ layout(push_constant) uniform TransformPC {
     mat4 World;
 };
 
-// Light/Shadow UBO (set 2, binding 0) — needed for shadow coordinate
-layout(set = 2, binding = 0) uniform ShadowLightUBO {
-    vec4  uLightDir;
-    vec4  uLightColor;
-    vec4  uAmbient;
-    vec4  uCameraPos;
-    mat4  uLightVP;
-    float uShadowBias;
-    float uShadowStrength;
-    float uShadowTexelSize;
-    float uLightSize;
-    vec4  uFogColor;
-    float uFogStart;
-    float uFogEnd;
-    vec2  _fogPad;            // std140: must be vec2 (8B) not float[2] (stride-16 = 32B)
-};
+#include "sleak/shadow_light.glsl"
+#include "sleak/frame.glsl"
 
 layout(location = 0) out vec3 fragWorldPos;
 layout(location = 1) out vec3 fragWorldNorm;
@@ -45,6 +32,7 @@ layout(location = 6) out vec4 fragShadowCoord;
 void main() {
     gl_Position = WVP * vec4(inPosition, 1.0);
     gl_Position.y = -gl_Position.y;  // Vulkan Y-axis flip
+    gl_Position = SleakFrameGuardClip(gl_Position);
 
     vec4 worldPos = World * vec4(inPosition, 1.0);
     fragWorldPos = worldPos.xyz;
diff --git a/Game/assets/shaders/gbuffer_voxel.vert.spv b/Game/assets/shaders/gbuffer_voxel.vert.spv
index 0204bf0..63927d6 100644
Binary files a/Game/assets/shaders/gbuffer_voxel.vert.spv and b/Game/assets/shaders/gbuffer_voxel.vert.spv differ
diff --git a/Game/assets/shaders/lighting_pass_gl.frag b/Game/assets/shaders/lighting_pass_gl.frag
index 04b31ac..ebce548 100644
--- a/Game/assets/shaders/lighting_pass_gl.frag
+++ b/Game/assets/shaders/lighting_pass_gl.frag
@@ -1,4 +1,5 @@
 #version 450 core
+#extension GL_GOOGLE_include_directive : require
 
 // Deferred lighting pass.
 // Reads the 4 GBuffer textures (bound at units 8-11),
@@ -26,6 +27,8 @@ layout(binding = 16) uniform sampler2D   brdfLUT;
 // Shadow map (already bound at unit 3 by the shadow pass)
 layout(binding = 3) uniform sampler2DShadow shadowMap;
 
+#include "sleak/frame.glsl"
+
 // ---- UBOs ----
 struct LightData {
     vec3  Position;  uint Type;
@@ -138,7 +141,7 @@ float CalcShadowPCF(vec3 worldPos, float NdotL) {
     vec4 sc = ShadowLightVP * vec4(worldPos, 1.0);
     vec3 proj = sc.xyz / sc.w;
     proj.xy   = proj.xy * 0.5 + 0.5;
-    proj.z    = proj.z  * 0.5 + 0.5;   // remap [-1,1]->  [0,1] for OpenGL
+    proj.z    = SleakNdcToDepth(proj.z);
 
     if (proj.z > 1.0 || any(lessThan(proj.xy, vec2(0.0))) || any(greaterThan(proj.xy, vec2(1.0))))
         return 1.0;
@@ -160,11 +163,9 @@ float CalcShadowPCF(vec3 worldPos, float NdotL) {
     return mix(1.0, fadedShadow, ShadowStrength * edgeFade);
 }
 
-// Reconstruct world position from depth. OpenGL: no vertex Y-flip, and the
-// default clip depth range is [-1,1], so the stored [0,1] depth maps to
-// NDC.z = 2*depth-1 before InvViewProj.
+// World position of a GBuffer texel from its depth
 vec3 ReconstructWorldPos(vec2 uv, float depth) {
-    vec4 ndc   = vec4(uv * 2.0 - 1.0, depth * 2.0 - 1.0, 1.0);
+    vec4 ndc   = vec4(SleakUvToNdc(uv), SleakDepthToNdc(depth), 1.0);
     vec4 world = InvViewProj * ndc;
     return world.xyz / world.w;
 }
@@ -305,5 +306,5 @@ void main() {
     // ---- Fog ----
     color = ApplyFog(color, worldPos);
 
-    outColor = vec4(color, 1.0);
+    outColor = SleakFrameGuard(vec4(color, 1.0));
 }
diff --git a/Game/assets/shaders/shadow_depth_voxel.vert b/Game/assets/shaders/shadow_depth_voxel.vert
index 006b837..a371bea 100644
--- a/Game/assets/shaders/shadow_depth_voxel.vert
+++ b/Game/assets/shaders/shadow_depth_voxel.vert
@@ -1,4 +1,5 @@
 #version 450
+#extension GL_GOOGLE_include_directive : require
 
 // Shadow Depth Pass - Voxel Vertex Only
 // Compact VoxelVertex layout: only position needed for shadow map
@@ -8,6 +9,8 @@ layout(location = 1) in vec3 inNormal;
 layout(location = 2) in vec4 inColor;
 layout(location = 3) in vec2 inUV;
 
+#include "sleak/frame.glsl"
+
 // Push constant: LightVP*World in slot 0, World in slot 1
 layout(push_constant) uniform TransformPC {
     mat4 WVP;
@@ -15,5 +18,5 @@ layout(push_constant) uniform TransformPC {
 };
 
 void main() {
-    gl_Position = WVP * vec4(inPosition, 1.0);
+    gl_Position = SleakFrameGuardClip(WVP * vec4(inPosition, 1.0));
 }
diff --git a/Game/assets/shaders/shadow_depth_voxel.vert.spv b/Game/assets/shaders/shadow_depth_voxel.vert.spv
index f108978..5374b5f 100644
Binary files a/Game/assets/shaders/shadow_depth_voxel.vert.spv and b/Game/assets/shaders/shadow_depth_voxel.vert.spv differ
diff --git a/Game/assets/shaders/water_shader.frag b/Game/assets/shaders/water_shader.frag
index 5621827..5af8058 100644
--- a/Game/assets/shaders/water_shader.frag
+++ b/Game/assets/shaders/water_shader.frag
@@ -1,4 +1,5 @@
 #version 450
+#extension GL_GOOGLE_include_directive : require
 
 layout(location = 0) in vec3  fragWorldPos;
 layout(location = 1) in vec3  fragNormal;
@@ -7,28 +8,8 @@ layout(location = 4) in float fragTime;
 
 layout(location = 0) out vec4 outColor;
 
-// NOTE: see water_shader.vert — no MaterialUBO in the Vulkan layout.
-// Time comes from uCameraPos.w (interpolated via fragTime).
-layout(set = 2, binding = 0) uniform ShadowLightUBO {
-    vec4  uLightDir;
-    vec4  uLightColor;
-    vec4  uAmbient;
-    vec4  uCameraPos;
-    mat4  uLightVP;
-    float uShadowBias;
-    float uShadowStrength;
-    float uShadowTexelSize;
-    float uLightSize;
-    vec4  uFogColor;       // horizon
-    float uFogStart;
-    float uFogEnd;
-    vec2  _fogPad;         // std140: must be vec2 (8B), NOT float[2] (stride-16 = 32B)
-    vec4  uFogZenithColor; // zenith
-    float uHeightFogTop;
-    float uHeightFogDensity;
-    float uHeightFogFalloff;
-    float uHeightFogEnabled;
-};
+#include "sleak/shadow_light.glsl"
+#include "sleak/frame.glsl"
 
 layout(set = 3, binding = 0) uniform sampler2DShadow shadowMap;
 
@@ -553,5 +534,5 @@ void main() {
         color = mix(w.backdrop, color, w.edge);
     else
         alpha = FallbackAlpha(P, fragNormal);
-    outColor = vec4(clamp(color, vec3(0.0), vec3(MAX_HDR)), alpha);
+    outColor = SleakFrameGuard(vec4(clamp(color, vec3(0.0), vec3(MAX_HDR)), alpha));
 }
diff --git a/Game/assets/shaders/water_shader.frag.spv b/Game/assets/shaders/water_shader.frag.spv
index 425cc8f..3e1f3e1 100644
Binary files a/Game/assets/shaders/water_shader.frag.spv and b/Game/assets/shaders/water_shader.frag.spv differ
diff --git a/Game/assets/shaders/water_shader.vert b/Game/assets/shaders/water_shader.vert
index 6bbb803..617a14d 100644
--- a/Game/assets/shaders/water_shader.vert
+++ b/Game/assets/shaders/water_shader.vert
@@ -1,4 +1,5 @@
 #version 450
+#extension GL_GOOGLE_include_directive : require
 
 layout(location = 0) in vec3 inPosition;
 layout(location = 1) in vec3 inNormal;
@@ -10,24 +11,8 @@ layout(push_constant) uniform TransformPC {
     mat4 World;
 };
 
-// NOTE: The engine's Vulkan pipeline layout has no MaterialUBO slot (set 1 is
-// the bone UBO, used only by skinned shaders). Time is transported via
-// uCameraPos.w, which LightManager populates with a monotonic scene clock.
-layout(set = 2, binding = 0) uniform ShadowLightUBO {
-    vec4  uLightDir;
-    vec4  uLightColor;
-    vec4  uAmbient;
-    vec4  uCameraPos;
-    mat4  uLightVP;
-    float uShadowBias;
-    float uShadowStrength;
-    float uShadowTexelSize;
-    float uLightSize;
-    vec4  uFogColor;
-    float uFogStart;
-    float uFogEnd;
-    vec2  _fogPad;            // std140: must be vec2 (8B) not float[2] (stride-16 = 32B)
-};
+#include "sleak/shadow_light.glsl"
+#include "sleak/frame.glsl"
 
 // Scene read block (VertexLayoutDesc::transparentReadsScene)
 layout(set = 3, binding = 5) uniform SceneReadUBO {
@@ -53,7 +38,7 @@ void main() {
 
     fragWorldPos   = inPosition;
     fragNormal     = inNormal;
-    fragTime       = uCameraPos.w;    // scene clock stashed in cam.w by LightManager
+    fragTime       = uFrame.Time;
 
     float normalBias = uLightDir.w;
     fragShadowCoord  = uLightVP * (vec4(inPosition, 1.0) + vec4(inNormal * normalBias, 0.0));
diff --git a/Game/assets/shaders/water_shader.vert.spv b/Game/assets/shaders/water_shader.vert.spv
index 73123eb..3b949a3 100644
Binary files a/Game/assets/shaders/water_shader.vert.spv and b/Game/assets/shaders/water_shader.vert.spv differ
diff --git a/Game/assets/shaders/water_shader_gl.frag b/Game/assets/shaders/water_shader_gl.frag
index 696b055..5a7bb56 100644
--- a/Game/assets/shaders/water_shader_gl.frag
+++ b/Game/assets/shaders/water_shader_gl.frag
@@ -1,4 +1,5 @@
 #version 450 core
+#extension GL_GOOGLE_include_directive : require
 
 in vec3  fragWorldPos;
 in vec3  fragNormal;
@@ -47,6 +48,8 @@ layout(std140, binding = 5) uniform ShadowUBO {
 
 layout(binding = 3) uniform sampler2DShadow shadowMap;
 
+#include "sleak/frame.glsl"
+
 // Scene read (VertexLayoutDesc::transparentReadsScene)
 layout(binding = 4) uniform sampler2D   sceneColor;  // tonemapped + fogged
 layout(binding = 5) uniform sampler2D   sceneDepth;
@@ -598,5 +601,5 @@ void main() {
         color = mix(w.backdrop, color, w.edge);
     else
         alpha = FallbackAlpha(P, fragNormal);
-    outColor = vec4(color, alpha);
+    outColor = SleakFrameGuard(vec4(color, alpha));
 }
diff --git a/Game/assets/shaders/water_shader_gl.vert b/Game/assets/shaders/water_shader_gl.vert
index 378e49e..710f21e 100644
--- a/Game/assets/shaders/water_shader_gl.vert
+++ b/Game/assets/shaders/water_shader_gl.vert
@@ -1,4 +1,5 @@
 #version 450 core
+#extension GL_GOOGLE_include_directive : require
 
 layout(location = 0) in vec3 inPosition;
 layout(location = 1) in vec3 inNormal;
@@ -21,6 +22,8 @@ layout(std140, binding = 1) uniform MaterialUBO {
     float MatOpacity; float MatAlphaCutoff; float _matPad1, _matPad2;
 };
 
+#include "sleak/frame.glsl"
+
 layout(std140, binding = 5) uniform ShadowUBO {
     mat4  ShadowLightVP;
     float ShadowBias;
@@ -45,6 +48,6 @@ void main() {
     fragWorldPos  = inPosition;
     fragNormal    = inNormal;
     fragColor     = inColor;
-    fragTime      = MatTiling.x;     // game time from SetTiling()
+    fragTime      = uFrame.Time;
     fragShadowCoord = ShadowLightVP * vec4(inPosition, 1.0);
 }
diff --git a/Game/src/MainScene.cpp b/Game/src/MainScene.cpp
index a188f92..4cf4cfb 100644
--- a/Game/src/MainScene.cpp
+++ b/Game/src/MainScene.cpp
@@ -298,11 +298,6 @@ void MainScene::Update(float deltaTime) {
         m_chunkManager.SetShadowLightVP(lm ? lm->GetShadowLightVP() : nullptr);
         m_chunkManager.Update(pos.GetX(), pos.GetY(), pos.GetZ());
         m_chunkManager.RenderColumns();
-
-        // Animate water — pass game time through material tiling.x
-        if (m_waterMaterial) {
-            m_waterMaterial->SetTiling(m_gameTime, 1.0f);
-        }
         m_chunkManager.RenderWater();
 
         m_blockInteraction.RenderOutline();
diff --git a/scripts/compile_shaders.sh b/scripts/compile_shaders.sh
index fdb2cc4..bf7ec9f 100755
--- a/scripts/compile_shaders.sh
+++ b/scripts/compile_shaders.sh
@@ -11,6 +11,11 @@ SHADER_DIRS=(
   "$ROOT_DIR/Engine/assets/shaders"
   "$ROOT_DIR/Game/assets/shaders"
 )
+# Include libraries: engine sleak/, game craft/
+INCLUDE_FLAGS=(
+  -I "$ROOT_DIR/Engine/assets/shaders/include"
+  -I "$ROOT_DIR/Game/assets/shaders/include"
+)
 
 if ! command -v glslc >/dev/null; then
   echo "error: glslc not found" >&2
@@ -28,7 +33,7 @@ for dir in "${SHADER_DIRS[@]}"; do
   for shader in "$dir"/*.vert "$dir"/*.frag "$dir"/*.comp; do
     [[ -f "$shader" ]] || continue
     case "$(basename "$shader")" in *_gl.*) continue ;; esac
-    if glslc "$shader" -o "$shader.spv"; then
+    if glslc "${INCLUDE_FLAGS[@]}" "$shader" -o "$shader.spv"; then
       echo "compiled ${shader#$ROOT_DIR/} -> ${shader#$ROOT_DIR/}.spv"
       count=$((count + 1))
     else