diff --git a/framegen/CMakeLists.txt b/framegen/CMakeLists.txt
index f01c318..595774e 100644
--- a/framegen/CMakeLists.txt
+++ b/framegen/CMakeLists.txt
@@ -1,17 +1,8 @@
 cmake_minimum_required(VERSION 3.10)
 
-if(NOT LSFGVK_EXCESS_DEBUG)
-    set(CMAKE_C_VISIBILITY_PRESET "hidden")
-    set(CMAKE_CXX_VISIBILITY_PRESET "hidden")
-endif()
-
-if(LSFGVK_EXCESS_DEBUG)
-    add_compile_definitions(LSFGVK_EXCESS_DEBUG)
-endif()
-
 project(lsfg-vk-framegen
     DESCRIPTION "Lossless Scaling Frame Generation Backend"
-    LANGUAGES C CXX)
+    LANGUAGES C CXX) # FIXME: get rid of c language
 
 file(GLOB SOURCES
     "src/trans/*.cpp"
@@ -26,38 +17,37 @@ file(GLOB SOURCES
 
 add_library(lsfg-vk-framegen STATIC ${SOURCES})
 
-# target
 set_target_properties(lsfg-vk-framegen PROPERTIES
     CXX_STANDARD 20
-    CXX_STANDARD_REQUIRED ON)
+    CXX_STANDARD_REQUIRED ON
+    CXX_VISIBILITY_PRESET "hidden"
+    EXPORT_COMPILE_COMMANDS ON)
 target_include_directories(lsfg-vk-framegen SYSTEM
     PUBLIC include/thirdparty)
 target_include_directories(lsfg-vk-framegen
     PUBLIC include)
 
-# diagnostics
 if(CMAKE_BUILD_TYPE STREQUAL "Debug")
-    set_target_properties(lsfg-vk-framegen PROPERTIES
-        EXPORT_COMPILE_COMMANDS ON)
-endif()
+    if(NOT CMAKE_CXX_COMPILER_ID STREQUAL "Clang")
+        message(WARNING "Debug builds should use Clang for better diagnostics")
+    else()
+        message(STATUS "Building with further diagnostics")
 
-if(LSFGVK_EXCESS_DEBUG)
-    target_compile_options(lsfg-vk-framegen PRIVATE
-        -Weverything
-        # disable compat c++ flags
-        -Wno-pre-c++20-compat-pedantic
-        -Wno-pre-c++17-compat
-        -Wno-c++98-compat-pedantic
-        -Wno-c++98-compat
-        # disable other flags
-        -Wno-missing-designated-field-initializers
-        -Wno-shadow         # allow shadowing
-        -Wno-switch-enum    # ignore missing cases
-        -Wno-switch-default # ignore missing default
-        -Wno-padded         # ignore automatic padding
-        -Wno-cast-function-type-strict # for vulkan
-    )
+        set_target_properties(lsfg-vk-framegen PROPERTIES
+            CXX_CLANG_TIDY clang-tidy)
 
-    set_target_properties(lsfg-vk-framegen PROPERTIES
-        CXX_CLANG_TIDY clang-tidy)
+        target_compile_options(lsfg-vk-framegen PRIVATE
+            -Weverything
+            # disable incompatible warnings
+            -Wno-pre-c++20-compat-pedantic
+            -Wno-c++98-compat
+            -Wno-switch-default
+            -Wno-switch-enum
+            # disable noisy warnings
+            -Wno-missing-designated-field-initializers
+            -Wno-cast-function-type-strict
+            -Wno-padded
+            -Wno-shadow
+        )
+    endif()
 endif()
diff --git a/framegen/include/lsfg.hpp b/framegen/include/lsfg.hpp
index 81d879c..5b56ecb 100644
--- a/framegen/include/lsfg.hpp
+++ b/framegen/include/lsfg.hpp
@@ -7,10 +7,24 @@
 #include "vk/registry/shader_registry.hpp"
 
 #include <filesystem>
+#include <memory>
 
 namespace LSFG {
 
-    // FIXME: device picking
+    // FIXME: device picking, fp16 logic, etc.
+
+    /// Vulkan (and related) data structure.
+    struct VKD {
+        VK::Core::Instance instance;
+        VK::Core::Device device;
+        VK::Core::DescriptorPool dpool;
+
+        VK::Registry::ShaderRegistry registry;
+
+        VK::Pool::ShaderPool spool;
+
+        float flow{1.0F};
+    };
 
     ///
     /// Lossless Scaling Frame Generation instance.
@@ -25,15 +39,8 @@ namespace LSFG {
         /// @throws LSFG::error if lsfg creation fails.
         ///
         Instance(const std::filesystem::path& dll);
-
     private:
-        VK::Core::Instance vk;
-        VK::Core::Device vkd;
-
-        VK::Core::DescriptorPool pool;
-
-        VK::Registry::ShaderRegistry registry;
-        VK::Pool::ShaderPool shaders;
+        std::unique_ptr<VKD> vkd;
     };
 
 }
diff --git a/framegen/include/v31n/shaderchain/mipmaps.hpp b/framegen/include/v31n/shaderchain/mipmaps.hpp
new file mode 100644
index 0000000..8a811d0
--- /dev/null
+++ b/framegen/include/v31n/shaderchain/mipmaps.hpp
@@ -0,0 +1,22 @@
+#pragma once
+
+#include "vk/types/images.hpp"
+#include "vk/types/shader.hpp"
+
+#include <memory>
+
+namespace LSFG { struct VKD; }
+namespace LSFG::V31N::Shaderchain {
+
+    class Mipmaps {
+    public:
+        Mipmaps(VKD& vkd,
+            const VK::Core::Image& in1,
+            const VK::Core::Image& in2);
+    private:
+        std::unique_ptr<VK::Types::Shader> shader;
+
+        VK::Types::Images<7> mipmaps;
+    };
+
+}
diff --git a/framegen/include/vk/pool/buffer_pool.hpp b/framegen/include/vk/pool/buffer_pool.hpp
new file mode 100644
index 0000000..d1ff9be
--- /dev/null
+++ b/framegen/include/vk/pool/buffer_pool.hpp
@@ -0,0 +1,39 @@
+#pragma once
+
+#include "vk/core/buffer.hpp"
+
+#include <unordered_map>
+#include <cstdint>
+
+namespace VK::Pool {
+
+    ///
+    /// Pool of initialized buffers.
+    ///
+    class BufferPool {
+    public:
+        ///
+        /// Create a buffer pool.
+        ///
+        BufferPool() noexcept = default;
+
+        ///
+        /// Get or create a buffer.
+        ///
+        /// @param flow Flow scale
+        /// @param hdr Whether HDR is enabled
+        /// @param timestamp Timestamp of the frame
+        /// @param firstIter Whether this is the first iteration
+        /// @param firstIterS Whether this is the first iteration for the second pass
+        /// @return Preallocated buffer
+        ///
+        /// @throws VK::vulkan_error if buffer creation fails.
+        ///
+        [[nodiscard]] const Core::Buffer& getOrCreate(
+            const Core::Device& device, float flow, bool hdr,
+            float timestamp, bool firstIter, bool firstIterS);
+    private:
+        std::unordered_map<uint64_t, Core::Buffer> buffers;
+    };
+
+}
diff --git a/framegen/include/vk/types/shader.hpp b/framegen/include/vk/types/shader.hpp
index 1ea2fd8..2651a69 100644
--- a/framegen/include/vk/types/shader.hpp
+++ b/framegen/include/vk/types/shader.hpp
@@ -23,15 +23,28 @@ namespace VK::Types {
         /// Create a new shader instance.
         ///
         Shader(Pool::ShaderInstance shader,
-                std::vector<Core::DescriptorSet> sets)
-            : shader(std::move(shader)),
-            sets(std::move(sets)) {}
+                std::vector<Core::DescriptorSet> sets,
+                std::vector<Core::Sampler> samplers,
+                std::optional<Core::Buffer> buffer,
+                std::vector<std::vector<std::optional<Core::Image>>> inputs,
+                std::vector<std::vector<Core::Image>> outputs)
+            : shader(std::move(shader)), sets(std::move(sets)),
+              samplers(std::move(samplers)),
+              buffer(std::move(buffer)),
+              inputs(std::move(inputs)),
+              outputs(std::move(outputs)) {}
+
 
         /// TODO: remaining methods
 
     private:
         Pool::ShaderInstance shader;
         std::vector<Core::DescriptorSet> sets;
+
+        std::vector<Core::Sampler> samplers;
+        std::optional<Core::Buffer> buffer;
+        std::vector<std::vector<std::optional<Core::Image>>> inputs;
+        std::vector<std::vector<Core::Image>> outputs;
     };
 
     ///
diff --git a/framegen/src/lsfg.cpp b/framegen/src/lsfg.cpp
index 7b80b8d..fafe316 100644
--- a/framegen/src/lsfg.cpp
+++ b/framegen/src/lsfg.cpp
@@ -1,43 +1,52 @@
 #include "lsfg.hpp"
+#include "vk/registry/shader_registry.hpp"
+#include "vk/pool/shader_pool.hpp"
+#include "vk/core/descriptorpool.hpp"
+#include "vk/core/instance.hpp"
+#include "vk/core/device.hpp"
 #include "trans/rsrc.hpp"
-#include "vk/core/buffer.hpp"
-#include "vk/core/image.hpp"
-#include "vk/core/sampler.hpp"
-#include "vk/types/shader.hpp"
-
-#include <vulkan/vulkan_core.h>
 
 #include <filesystem>
-#include <vector>
+#include <utility>
+#include <memory>
 
 using namespace LSFG;
+using namespace VK;
+
+Instance::Instance(const std::filesystem::path& dll) {
+    VKD vkd{
+        .instance = Core::Instance(),
+        .device = Core::Device(vkd.instance, 0, false),
+        .dpool = Core::DescriptorPool(vkd.device),
+        .registry = Registry::ShaderRegistry(),
+        .spool = Pool::ShaderPool()
+    };
+    this->vkd = std::make_unique<VKD>(std::move(vkd));
 
-Instance::Instance(const std::filesystem::path& dll)
-        : vkd(vk, 0, false), pool(vkd) {
     // load shaders from dll file
-    const bool fp16 = vkd.supportsFP16();
-    Trans::RSRC::loadResources(dll, this->registry, fp16);
+    const bool fp16 = this->vkd->device.supportsFP16();
+    Trans::RSRC::loadResources(dll, this->vkd->registry, fp16);
 
     // ...
 
-    const auto sampler1 =
-        VK::Core::Sampler(vkd, VK_SAMPLER_ADDRESS_MODE_REPEAT, VK_COMPARE_OP_GREATER_OR_EQUAL, false);
-    const auto sampler2 =
-        VK::Core::Sampler(vkd, VK_SAMPLER_ADDRESS_MODE_CLAMP_TO_BORDER, VK_COMPARE_OP_ALWAYS, true);
-    const auto buffer0 =
-        VK::Core::Buffer(vkd, 256, VK_BUFFER_USAGE_STORAGE_BUFFER_BIT);
-    const auto input0 =
-        VK::Core::Image(vkd, { 1920, 1080 });
-    const auto input1 =
-        VK::Core::Image(vkd, { 1920, 1080 });
-    const std::vector<VK::Core::Image> mipmaps{
-        input0, input0
-    };
+    // const auto sampler1 =
+    //     VK::Core::Sampler(vkd, VK_SAMPLER_ADDRESS_MODE_REPEAT, VK_COMPARE_OP_GREATER_OR_EQUAL, false);
+    // const auto sampler2 =
+    //     VK::Core::Sampler(vkd, VK_SAMPLER_ADDRESS_MODE_CLAMP_TO_BORDER, VK_COMPARE_OP_ALWAYS, true);
+    // const auto buffer0 =
+    //     VK::Core::Buffer(vkd, 256, VK_BUFFER_USAGE_STORAGE_BUFFER_BIT);
+    // const auto input0 =
+    //     VK::Core::Image(vkd, { 1920, 1080 });
+    // const auto input1 =
+    //     VK::Core::Image(vkd, { 1920, 1080 });
+    // const std::vector<VK::Core::Image> mipmaps{
+    //     input0, input0
+    // };
 
-    auto shader = VK::Types::ShaderBuilder(vkd, registry, this->shaders, "alpha[0]")
-        .withSamplers(sampler1, sampler2)
-        .withBuffer(buffer0)
-        .addTemporalInput({ input0, input1 })
-        .addOutputs(mipmaps)
-        .build(vkd, this->pool);
+    // auto shader = VK::Types::ShaderBuilder(vkd, registry, this->shaders, "alpha[0]")
+    //     .withSamplers(sampler1, sampler2)
+    //     .withBuffer(buffer0)
+    //     .addTemporalInput({ input0, input1 })
+    //     .addOutputs(mipmaps)
+    //     .build(vkd, this->pool);
 }
diff --git a/framegen/src/v31n/shaderchain/mipmaps.cpp b/framegen/src/v31n/shaderchain/mipmaps.cpp
new file mode 100644
index 0000000..ac6a854
--- /dev/null
+++ b/framegen/src/v31n/shaderchain/mipmaps.cpp
@@ -0,0 +1,48 @@
+#include "v31n/shaderchain/mipmaps.hpp"
+#include "vk/types/shader.hpp"
+#include "vk/core/sampler.hpp"
+#include "vk/core/buffer.hpp"
+#include "vk/core/image.hpp"
+#include "lsfg.hpp"
+
+#include <vulkan/vulkan_core.h>
+
+#include <vector>
+
+using namespace LSFG::V31N::Shaderchain;
+using namespace VK;
+
+Mipmaps::Mipmaps(LSFG::VKD& vkd, const Core::Image& in1, const Core::Image& in2) {
+    // TODO: logic for buffer and sampler
+    Core::Sampler sampler{vkd.device,
+        VK_SAMPLER_ADDRESS_MODE_CLAMP_TO_BORDER,
+        VK_COMPARE_OP_NEVER,
+        false};
+    Core::Buffer buffer{vkd.device, nullptr, 0, VK_BUFFER_USAGE_UNIFORM_BUFFER_BIT};
+
+    // create output images
+    const VkExtent2D extent{
+        .width = static_cast<uint32_t>(
+            static_cast<float>(in1.getExtent().width) / vkd.flow),
+        .height = static_cast<uint32_t>(
+            static_cast<float>(in1.getExtent().height) / vkd.flow)
+    };
+
+    std::vector<Core::Image> mipmapVector{};
+    mipmapVector.reserve(7);
+    for (size_t i = 0; i < 7; i++)
+        mipmapVector.emplace_back(vkd.device,
+        VkExtent2D { extent.width >> i, extent.height >> i },
+        VK_FORMAT_R8_UNORM);
+    this->mipmaps = VK::Types::Images<7>(mipmapVector);
+
+    // create shaders
+    auto shader = Types::ShaderBuilder(
+            vkd.device, vkd.registry, vkd.spool, "mipmaps", 2)
+        .withSamplers(sampler)
+        .withBuffer(buffer)
+        .addTemporalInput({ in1, in2 })
+        .addOutputs(this->mipmaps.all())
+        .build(vkd.device, vkd.dpool);
+    this->shader = std::make_unique<Types::Shader>(std::move(shader));
+}
diff --git a/framegen/src/vk/pool/buffer_pool.cpp b/framegen/src/vk/pool/buffer_pool.cpp
new file mode 100644
index 0000000..b293c06
--- /dev/null
+++ b/framegen/src/vk/pool/buffer_pool.cpp
@@ -0,0 +1,54 @@
+#include "vk/pool/buffer_pool.hpp"
+#include "vk/core/buffer.hpp"
+#include "vk/core/device.hpp"
+
+#include <vulkan/vulkan_core.h>
+
+#include <cstdint>
+#include <utility>
+#include <array>
+
+using namespace VK::Pool;
+
+struct ConstantBuffer {
+    std::array<uint32_t, 2> inputOffset;
+    uint32_t firstIter;
+    uint32_t firstIterS;
+    uint32_t advancedColorKind;
+    uint32_t hdrSupport;
+    float resolutionInvScale;
+    float timestamp;
+    float uiThreshold;
+    std::array<uint32_t, 3> pad;
+};
+
+const VK::Core::Buffer& BufferPool::getOrCreate(
+        const Core::Device& device, float flow, bool hdr,
+        float timestamp, bool firstIter, bool firstIterS) {
+    uint64_t hash = 0;
+    const union { float f; uint32_t i; } u{
+        .f = timestamp };
+    hash |= u.i; // NOLINT
+    hash |= static_cast<uint64_t>(firstIter) << 32;
+    hash |= static_cast<uint64_t>(firstIterS) << 33;
+
+    const auto it = buffers.find(hash);
+    if (it != buffers.end()) {
+        return it->second;
+    }
+
+    // create buffer
+    const ConstantBuffer data{
+        .inputOffset = { 0, 0 },
+        .advancedColorKind = hdr ? 2U : 0U,
+        .hdrSupport = hdr,
+        .resolutionInvScale = flow,
+        .timestamp = timestamp,
+        .uiThreshold = 0.5F,
+    };
+
+    Core::Buffer buffer(device, data, VK_BUFFER_USAGE_UNIFORM_BUFFER_BIT);
+
+    const auto i = buffers.emplace(hash, std::move(buffer));
+    return i.first->second;
+}
diff --git a/framegen/src/vk/types/shader.cpp b/framegen/src/vk/types/shader.cpp
index e2f7b96..f2c728f 100644
--- a/framegen/src/vk/types/shader.cpp
+++ b/framegen/src/vk/types/shader.cpp
@@ -1,4 +1,4 @@
-#include "vk/types/shader.hpp"
+ #include "vk/types/shader.hpp"
 #include "vk/core/descriptorpool.hpp"
 #include "vk/core/descriptorset.hpp"
 #include "vk/core/sampler.hpp"
@@ -86,5 +86,11 @@ Shader ShaderBuilder::build(const Core::Device& vkd,
             std::move(this->inputs.at(i)),
             std::move(this->outputs.at(i)),
             this->samplers, this->buffer);
-    return { this->shader, std::move(sets) };
+    return {
+        this->shader, std::move(sets),
+        std::move(this->samplers),
+        std::move(this->buffer),
+        std::move(this->inputs),
+        std::move(this->outputs)
+    };
 }