134 files changed, 1119 insertions, 1086 deletions

diff --git a/.gitignore b/.gitignore
index cc01af7..b631914 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,6 +1,6 @@
-candy_gear
-candy_gear.exe
-doc
+/candy_gear
+/candy_gear.exe
+/dox_doc
 pkg
 
 mruby-*
diff --git a/Doxyfile b/Doxyfile
index 044e484..b25320c 100644
--- a/Doxyfile
+++ b/Doxyfile
@@ -58,7 +58,7 @@ PROJECT_LOGO           =
 # entered, it will be relative to the location where doxygen was started. If
 # left blank the current directory will be used.
 
-OUTPUT_DIRECTORY       = doc
+OUTPUT_DIRECTORY       = dox_doc
 
 # If the CREATE_SUBDIRS tag is set to YES then doxygen will create 4096 sub-
 # directories (in 2 levels) under the output directory of each output format and
diff --git a/doc/architecture.markdown b/doc/architecture.markdown
new file mode 100644
index 0000000..e63f23c
--- /dev/null
+++ b/doc/architecture.markdown
@@ -0,0 +1,10 @@
+Architecture
+============
+
+This project is split into two parts BluCat and CandyGear.
+BluCat is the C++ engine, and CandyGear is the mruby engine.
+BluCat consists of a few modules:
+
+- COM: common code that other modules use.
+- INT: integration of all modules.
+- GRA: graphics module.
diff --git a/src/blucat/command.cpp b/src/blu_cat/com/command.cpp
index a1d3240..a1d3240 100644
--- a/src/blucat/command.cpp
+++ b/src/blu_cat/com/command.cpp
diff --git a/src/blucat/command.hpp b/src/blu_cat/com/command.hpp
index 47552a5..5079c58 100644
--- a/src/blucat/command.hpp
+++ b/src/blu_cat/com/command.hpp
@@ -14,8 +14,8 @@
  * limitations under the License.
  */
 
-#ifndef CANDY_GEAR_COMMAND_CHAIN_H
-#define CANDY_GEAR_COMMAND_CHAIN_H 1
+#ifndef BLU_CAT_COM_COMMAND_CHAIN_H
+#define BLU_CAT_COM_COMMAND_CHAIN_H 1
 
 #include <cstdint>
 #include <initializer_list>
@@ -89,4 +89,4 @@ public:
 
 };
 
-#endif /* CANDY_GEAR_COMMAND_CHAIN_H */
+#endif /* BLU_CAT_COM_COMMAND_CHAIN_H */
diff --git a/src/blucat/job_queue.cpp b/src/blu_cat/com/job_queue.cpp
index 49bf34f..beaf989 100644
--- a/src/blucat/job_queue.cpp
+++ b/src/blu_cat/com/job_queue.cpp
@@ -18,6 +18,9 @@
 
 #include <chrono>
 
+namespace BluCat::COM
+{
+
 JobQueue::JobQueue():
   jobs{},
   _stop{false}
@@ -59,3 +62,5 @@ JobQueue::pop()
     return Job{nullptr};
   }
 }
+
+}
diff --git a/src/blucat/job_queue.hpp b/src/blu_cat/com/job_queue.hpp
index 2a7735b..856946d 100644
--- a/src/blucat/job_queue.hpp
+++ b/src/blu_cat/com/job_queue.hpp
@@ -14,8 +14,8 @@
  * limitations under the License.
  */
 
-#ifndef CANDY_GEAR_JOB_QUEUE_H
-#define CANDY_GEAR_JOB_QUEUE_H 1
+#ifndef BLU_CAT_COM_JOB_QUEUE_H
+#define BLU_CAT_COM_JOB_QUEUE_H 1
 
 #include <atomic>
 #include <condition_variable>
@@ -23,6 +23,9 @@
 #include <functional>
 #include <mutex>
 
+namespace BluCat::COM
+{
+
 class Worker;
 
 typedef std::function<void(void)> Job;
@@ -49,4 +52,6 @@ public:
   push(Job job);
 };
 
-#endif /* CANDY_GEAR_JOB_QUEUE_H */
+}
+
+#endif /* BLU_CAT_COM_JOB_QUEUE_H */
diff --git a/src/blucat/worker.cpp b/src/blu_cat/com/worker.cpp
index bcf654e..847b571 100644
--- a/src/blucat/worker.cpp
+++ b/src/blu_cat/com/worker.cpp
@@ -18,6 +18,9 @@
 
 #include <thread>
 
+namespace BluCat::COM
+{
+
 Worker::Worker(JobQueue *job_queue):
   job_queue{job_queue}
 {
@@ -32,3 +35,5 @@ Worker::operator()()
     if(job) job();
   }
 }
+
+}
diff --git a/src/blucat/worker.hpp b/src/blu_cat/com/worker.hpp
index 449e1b0..d74aa24 100644
--- a/src/blucat/worker.hpp
+++ b/src/blu_cat/com/worker.hpp
@@ -14,11 +14,14 @@
  * limitations under the License.
  */
 
-#ifndef CANDY_GEAR_WORKER_H
-#define CANDY_GEAR_WORKER_H 1
+#ifndef BLU_CAT_COM_WORKER_H
+#define BLU_CAT_COM_WORKER_H 1
 
 #include "job_queue.hpp"
 
+namespace BluCat::COM
+{
+
 class Worker
 {
   JobQueue *job_queue;
@@ -30,4 +33,6 @@ public:
   operator()();
 };
 
-#endif /* CANDY_GEAR_WORKER_H */
+}
+
+#endif /* BLU_CAT_COM_WORKER_H */
diff --git a/src/blucat/animation.cpp b/src/blu_cat/gra/animation.cpp
index b4daeef..dc2c281 100644
--- a/src/blucat/animation.cpp
+++ b/src/blu_cat/gra/animation.cpp
@@ -16,7 +16,7 @@
 
 #include "animation.hpp"
 
-namespace BluCat
+namespace BluCat::GRA
 {
 
 Bone::Bone(glm::mat4 offset_matrix):
diff --git a/src/blucat/animation.hpp b/src/blu_cat/gra/animation.hpp
index b1ddd06..1275b48 100644
--- a/src/blucat/animation.hpp
+++ b/src/blu_cat/gra/animation.hpp
@@ -14,15 +14,15 @@
  * limitations under the License.
  */
 
-#ifndef CANDY_GEAR_BLUCAT_ANIMATION_H
-#define CANDY_GEAR_BLUCAT_ANIMATION_H 1
+#ifndef BLU_CAT_GRA_ANIMATION_H
+#define BLU_CAT_GRA_ANIMATION_H 1
 
 #include <vector>
 
 #include "vulkan.hpp"
 #include "animation/frame.hpp"
 
-namespace BluCat
+namespace BluCat::GRA
 {
 
 struct Bone
@@ -48,4 +48,4 @@ struct Animation
 
 }
 
-#endif /* CANDY_GEAR_BLUCAT_ANIMATION_H */
+#endif /* BLU_CAT_GRA_ANIMATION_H */
diff --git a/src/blucat/animation/frame.hpp b/src/blu_cat/gra/animation/frame.hpp
index 663483d..b1ea913 100644
--- a/src/blucat/animation/frame.hpp
+++ b/src/blu_cat/gra/animation/frame.hpp
@@ -14,14 +14,14 @@
  * limitations under the License.
  */
 
-#ifndef CANDY_GEAR_BLUCAT_FRAME_H
-#define CANDY_GEAR_BLUCAT_FRAME_H 1
+#ifndef BLU_CAT_GRA_FRAME_H
+#define BLU_CAT_GRA_FRAME_H 1
 
 #include <vector>
 
 #include "../vulkan.hpp"
 
-namespace BluCat
+namespace BluCat::GRA
 {
 
 template<typename T>
@@ -82,4 +82,4 @@ struct Channel
 };
 
 }
-#endif /* CANDY_GEAR_BLUCAT_FRAME_H */
+#endif /* BLU_CAT_GRA_FRAME_H */
diff --git a/src/blucat/base_buffer.cpp b/src/blu_cat/gra/base_buffer.cpp
index 762c89a..1add9fb 100644
--- a/src/blucat/base_buffer.cpp
+++ b/src/blu_cat/gra/base_buffer.cpp
@@ -16,7 +16,7 @@
 
 #include "base_buffer.hpp"
 
-namespace BluCat
+namespace BluCat::GRA
 {
 
 const CommandChain BaseBuffer::loader{
diff --git a/src/blucat/base_buffer.hpp b/src/blu_cat/gra/base_buffer.hpp
index cdc9f9c..cb4cdf8 100644
--- a/src/blucat/base_buffer.hpp
+++ b/src/blu_cat/gra/base_buffer.hpp
@@ -14,14 +14,14 @@
  * limitations under the License.
  */
 
-#ifndef CANDY_GEAR_BLUCAT_BASE_BUFFER_H
-#define CANDY_GEAR_BLUCAT_BASE_BUFFER_H 1
+#ifndef BLU_CAT_GRA_BASE_BUFFER_H
+#define BLU_CAT_GRA_BASE_BUFFER_H 1
 
-#include "command.hpp"
+#include "../com/command.hpp"
 #include "vulkan.hpp"
 #include "device.hpp"
 
-namespace BluCat
+namespace BluCat::GRA
 {
 
 class BaseBuffer
@@ -53,4 +53,4 @@ class BaseBuffer
 
 }
 
-#endif /* CANDY_GEAR_BLUCAT_BASE_BUFFER_H */
+#endif /* BLU_CAT_GRA_BASE_BUFFER_H */
diff --git a/src/blucat/binary_reader.cpp b/src/blu_cat/gra/binary_reader.cpp
index 14fc39c..14fc39c 100644
--- a/src/blucat/binary_reader.cpp
+++ b/src/blu_cat/gra/binary_reader.cpp
diff --git a/src/blucat/binary_reader.hpp b/src/blu_cat/gra/binary_reader.hpp
index 1995402..1995402 100644
--- a/src/blucat/binary_reader.hpp
+++ b/src/blu_cat/gra/binary_reader.hpp
diff --git a/src/blucat/character.cpp b/src/blu_cat/gra/character.cpp
index 220295d..f0e7512 100644
--- a/src/blucat/character.cpp
+++ b/src/blu_cat/gra/character.cpp
@@ -16,8 +16,8 @@
 
 #include "character.hpp"
 
-#include "command.hpp"
-#include "core.hpp"
+#include "../com/command.hpp"
+#include "../int/core.hpp"
 #include "font.hpp"
 #include "image.hpp"
 #include "source_buffer.hpp"
@@ -27,16 +27,16 @@ namespace
 
 struct CharacterBuilder
 {
-  BluCat::Character *character;
+  BluCat::GRA::Character *character;
   FT_Face face;
   uint32_t character_code;
 
   CharacterBuilder(
-    BluCat::Character *character, FT_Face face, uint32_t character_code);
+    BluCat::GRA::Character *character, FT_Face face, uint32_t character_code);
 };
 
 CharacterBuilder::CharacterBuilder(
-  BluCat::Character *character, FT_Face face, uint32_t character_code):
+  BluCat::GRA::Character *character, FT_Face face, uint32_t character_code):
   character{character},
   face{face},
   character_code{character_code}
@@ -104,8 +104,8 @@ load_image(void *obj)
     }
   }
 
-  BluCat::SourceBuffer source_image_buffer{
-		BluCat::core.vk_device_with_swapchain, source_image_raw.data(),
+  BluCat::GRA::SourceBuffer source_image_buffer{
+		BluCat::INT::core.vk_device_with_swapchain, source_image_raw.data(),
     image_size};
 
   { // Create Vulkan image.
@@ -116,8 +116,8 @@ load_image(void *obj)
       vk_extent3d.height = self->face->glyph->bitmap.rows;
       vk_extent3d.depth = 1;
 
-      BluCat::Image::create(
-        BluCat::core.vk_device_with_swapchain,
+      BluCat::GRA::Image::create(
+        BluCat::INT::core.vk_device_with_swapchain,
 	&self->character->image,
 	&self->character->device_memory,
 	VK_FORMAT_R8G8B8A8_UNORM,
@@ -126,21 +126,21 @@ load_image(void *obj)
 	VK_IMAGE_TILING_OPTIMAL,
 	VK_IMAGE_USAGE_TRANSFER_SRC_BIT | VK_IMAGE_USAGE_TRANSFER_DST_BIT);
     }
-    catch(BluCat::Image::Error error)
+    catch(BluCat::GRA::Image::Error error)
     {
       throw CommandError{error.what()};
     }
   }
 
   { // Copy image from buffer into image.
-    auto queue_family{BluCat::core.vk_device_with_swapchain->
+    auto queue_family{BluCat::INT::core.vk_device_with_swapchain->
       get_queue_family_with_presentation()};
     auto queue{queue_family->get_queue()};
-    BluCat::CommandPool command_pool{queue_family, 1};
+    BluCat::GRA::CommandPool command_pool{queue_family, 1};
     VkCommandBuffer vk_command_buffer{command_pool.command_buffers[0]};
 
     queue.submit_one_time_command(vk_command_buffer, [&](){
-      BluCat::Image::move_image_state(
+      BluCat::GRA::Image::move_image_state(
         vk_command_buffer, self->character->image, VK_FORMAT_R8G8B8A8_UNORM,
         0, VK_ACCESS_TRANSFER_WRITE_BIT, VK_IMAGE_LAYOUT_UNDEFINED,
         VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL, VK_PIPELINE_STAGE_HOST_BIT,
@@ -162,7 +162,7 @@ load_image(void *obj)
         vk_command_buffer, source_image_buffer.buffer, self->character->image,
         VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL, 1, &image_copy);
 
-      BluCat::Image::move_image_state(
+      BluCat::GRA::Image::move_image_state(
         vk_command_buffer, self->character->image, VK_FORMAT_R8G8B8A8_UNORM,
         VK_ACCESS_TRANSFER_WRITE_BIT, VK_ACCESS_SHADER_READ_BIT,
         VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL,
@@ -179,10 +179,10 @@ unload_image(void *obj)
   auto self = static_cast<CharacterBuilder*>(obj);
 
   vkDestroyImage(
-    BluCat::core.vk_device_with_swapchain->device, self->character->image,
+    BluCat::INT::core.vk_device_with_swapchain->device, self->character->image,
 		nullptr);
   vkFreeMemory(
-    BluCat::core.vk_device_with_swapchain->device,
+    BluCat::INT::core.vk_device_with_swapchain->device,
 		self->character->device_memory, nullptr);
 }
 
@@ -192,7 +192,7 @@ const CommandChain loader{
 
 }
 
-namespace BluCat
+namespace BluCat::GRA
 {
 
 Character::Character(FT_Face face, uint32_t character_code)
diff --git a/src/blucat/character.hpp b/src/blu_cat/gra/character.hpp
index 9d0829f..8968384 100644
--- a/src/blucat/character.hpp
+++ b/src/blu_cat/gra/character.hpp
@@ -14,8 +14,8 @@
  * limitations under the License.
  */
 
-#ifndef CANDY_GEAR_BLUCAT_CHARACTER_H
-#define CANDY_GEAR_BLUCAT_CHARACTER_H 1
+#ifndef BLU_CAT_GRA_CHARACTER_H
+#define BLU_CAT_GRA_CHARACTER_H 1
 
 #include <ft2build.h>
 #include FT_FREETYPE_H
@@ -24,7 +24,7 @@
 
 #include <vector>
 
-namespace BluCat
+namespace BluCat::GRA
 {
 
 struct Character
@@ -46,4 +46,4 @@ struct Character
 
 }
 
-#endif /* CANDY_GEAR_BLUCAT_CHARACTER_H */
+#endif /* BLU_CAT_GRA_CHARACTER_H */
diff --git a/src/blucat/command_pool.cpp b/src/blu_cat/gra/command_pool.cpp
index 898d7ae..2602522 100644
--- a/src/blucat/command_pool.cpp
+++ b/src/blu_cat/gra/command_pool.cpp
@@ -16,7 +16,7 @@
 
 #include "command_pool.hpp"
 
-namespace BluCat
+namespace BluCat::GRA
 {
 
 const CommandChain CommandPool::loader{
diff --git a/src/blucat/command_pool.hpp b/src/blu_cat/gra/command_pool.hpp
index 92451d8..7487365 100644
--- a/src/blucat/command_pool.hpp
+++ b/src/blu_cat/gra/command_pool.hpp
@@ -14,16 +14,16 @@
  * limitations under the License.
  */
 
-#ifndef CANDY_GEAR_BLUCAT_COMMAND_POOL_H
-#define CANDY_GEAR_BLUCAT_COMMAND_POOL_H 1
+#ifndef BLU_CAT_GRA_COMMAND_POOL_H
+#define BLU_CAT_GRA_COMMAND_POOL_H 1
 
 #include <vector>
 
-#include "command.hpp"
+#include "../com/command.hpp"
 #include "device.hpp"
 #include "vulkan.hpp"
 
-namespace BluCat
+namespace BluCat::GRA
 {
 
 class CommandPool
@@ -56,4 +56,4 @@ private:
 
 }
 
-#endif /* CANDY_GEAR_BLUCAT_COMMAND_POOL_H */
+#endif /* BLU_CAT_GRA_COMMAND_POOL_H */
diff --git a/src/blucat/descriptor_set_layout.cpp b/src/blu_cat/gra/descriptor_set_layout.cpp
index 7d32346..e1e8852 100644
--- a/src/blucat/descriptor_set_layout.cpp
+++ b/src/blu_cat/gra/descriptor_set_layout.cpp
@@ -18,7 +18,7 @@
 
 #include <array>
 
-#include "core.hpp"
+#include "../int/core.hpp"
 
 namespace
 {
@@ -26,7 +26,7 @@ namespace
 void
 load_world(void *obj)
 {
-  auto self = static_cast<BluCat::DescriptorSetLayout*>(obj);
+  auto self = static_cast<BluCat::GRA::DescriptorSetLayout*>(obj);
 
   std::array<VkDescriptorSetLayoutBinding, 2> set_layouts{};
   set_layouts[0].binding = 0;
@@ -49,7 +49,7 @@ load_world(void *obj)
   layout_info.pBindings = set_layouts.data();
 
   if(vkCreateDescriptorSetLayout(
-       BluCat::core.vk_device_with_swapchain->device, &layout_info, nullptr,
+       BluCat::INT::core.vk_device_with_swapchain->device, &layout_info, nullptr,
        &self->world) != VK_SUCCESS)
     throw CommandError{
       "Failed to create Vulkan descriptor set layout for world view."};
@@ -58,16 +58,16 @@ load_world(void *obj)
 void
 unload_world(void *obj)
 {
-  auto self = static_cast<BluCat::DescriptorSetLayout*>(obj);
+  auto self = static_cast<BluCat::GRA::DescriptorSetLayout*>(obj);
 
   vkDestroyDescriptorSetLayout(
-    BluCat::core.vk_device_with_swapchain->device, self->world, nullptr);
+    BluCat::INT::core.vk_device_with_swapchain->device, self->world, nullptr);
 }
 
 void
 load_view(void *obj)
 {
-  auto self = static_cast<BluCat::DescriptorSetLayout*>(obj);
+  auto self = static_cast<BluCat::GRA::DescriptorSetLayout*>(obj);
 
   std::array<VkDescriptorSetLayoutBinding, 1> layout_bindings{};
 
@@ -85,7 +85,7 @@ load_view(void *obj)
   layout_info.pBindings = layout_bindings.data();
 
   if(vkCreateDescriptorSetLayout(
-       BluCat::core.vk_device_with_swapchain->device, &layout_info, nullptr,
+       BluCat::INT::core.vk_device_with_swapchain->device, &layout_info, nullptr,
        &self->view) != VK_SUCCESS)
     throw CommandError{
       "Failed to create Vulkan descriptor set layout for view."};
@@ -94,16 +94,16 @@ load_view(void *obj)
 void
 unload_view(void *obj)
 {
-  auto self = static_cast<BluCat::DescriptorSetLayout*>(obj);
+  auto self = static_cast<BluCat::GRA::DescriptorSetLayout*>(obj);
 
   vkDestroyDescriptorSetLayout(
-    BluCat::core.vk_device_with_swapchain->device, self->view, nullptr);
+    BluCat::INT::core.vk_device_with_swapchain->device, self->view, nullptr);
 }
 
 void
 load_texture(void *obj)
 {
-  auto self = static_cast<BluCat::DescriptorSetLayout*>(obj);
+  auto self = static_cast<BluCat::GRA::DescriptorSetLayout*>(obj);
 
   std::array<VkDescriptorSetLayoutBinding, 1> layout_bindings{};
 
@@ -122,7 +122,7 @@ load_texture(void *obj)
   layout_info.pBindings = layout_bindings.data();
 
   if(vkCreateDescriptorSetLayout(
-       BluCat::core.vk_device_with_swapchain->device, &layout_info, nullptr,
+       BluCat::INT::core.vk_device_with_swapchain->device, &layout_info, nullptr,
        &self->texture) != VK_SUCCESS)
     throw CommandError{
       "Failed to create Vulkan descriptor set layout for textures."};
@@ -131,16 +131,16 @@ load_texture(void *obj)
 void
 unload_texture(void *obj)
 {
-  auto self = static_cast<BluCat::DescriptorSetLayout*>(obj);
+  auto self = static_cast<BluCat::GRA::DescriptorSetLayout*>(obj);
 
   vkDestroyDescriptorSetLayout(
-    BluCat::core.vk_device_with_swapchain->device, self->texture, nullptr);
+    BluCat::INT::core.vk_device_with_swapchain->device, self->texture, nullptr);
 }
 
 void
 load_model(void *obj)
 {
-  auto self = static_cast<BluCat::DescriptorSetLayout*>(obj);
+  auto self = static_cast<BluCat::GRA::DescriptorSetLayout*>(obj);
 
   std::array<VkDescriptorSetLayoutBinding, 1> layout_bindings;
   layout_bindings[0].binding = 0;
@@ -157,7 +157,7 @@ load_model(void *obj)
   layout_info.pBindings = layout_bindings.data();
 
   if(vkCreateDescriptorSetLayout(
-       BluCat::core.vk_device_with_swapchain->device, &layout_info, nullptr,
+       BluCat::INT::core.vk_device_with_swapchain->device, &layout_info, nullptr,
        &self->model) != VK_SUCCESS)
     throw CommandError{
       "Failed to create Vulkan descriptor set layout for model instance."};
@@ -166,10 +166,10 @@ load_model(void *obj)
 void
 unload_model(void *obj)
 {
-  auto self = static_cast<BluCat::DescriptorSetLayout*>(obj);
+  auto self = static_cast<BluCat::GRA::DescriptorSetLayout*>(obj);
 
   vkDestroyDescriptorSetLayout(
-    BluCat::core.vk_device_with_swapchain->device, self->model, nullptr);
+    BluCat::INT::core.vk_device_with_swapchain->device, self->model, nullptr);
 }
 
 const CommandChain loader{
@@ -181,7 +181,7 @@ const CommandChain loader{
 
 }
 
-namespace BluCat
+namespace BluCat::GRA
 {
 
 DescriptorSetLayout::DescriptorSetLayout()
diff --git a/src/blucat/descriptor_set_layout.hpp b/src/blu_cat/gra/descriptor_set_layout.hpp
index 0724e40..42003b9 100644
--- a/src/blucat/descriptor_set_layout.hpp
+++ b/src/blu_cat/gra/descriptor_set_layout.hpp
@@ -14,12 +14,12 @@
  * limitations under the License.
  */
 
-#ifndef CANDY_GEAR_BLUCAT_DESCRIPTOR_SET_LAYOUT_H
-#define CANDY_GEAR_BLUCAT_DESCRIPTOR_SET_LAYOUT_H 1
+#ifndef BLU_CAT_GRA_DESCRIPTOR_SET_LAYOUT_H
+#define BLU_CAT_GRA_DESCRIPTOR_SET_LAYOUT_H 1
 
 #include "vulkan.hpp"
 
-namespace BluCat
+namespace BluCat::GRA
 {
 
 struct DescriptorSetLayout
@@ -35,4 +35,4 @@ struct DescriptorSetLayout
 
 }
 
-#endif /* CANDY_GEAR_BLUCAT_DESCRIPTOR_SET_LAYOUT_H */
+#endif /* BLU_CAT_GRA_DESCRIPTOR_SET_LAYOUT_H */
diff --git a/src/blucat/destination_buffer.cpp b/src/blu_cat/gra/destination_buffer.cpp
index ea5f31e..3c53db4 100644
--- a/src/blucat/destination_buffer.cpp
+++ b/src/blu_cat/gra/destination_buffer.cpp
@@ -18,7 +18,7 @@
 
 #include "command_pool.hpp"
 
-namespace BluCat
+namespace BluCat::GRA
 {
 
 DestinationBuffer::DestinationBuffer(
diff --git a/src/blucat/destination_buffer.hpp b/src/blu_cat/gra/destination_buffer.hpp
index 7f5fb4b..7df1e50 100644
--- a/src/blucat/destination_buffer.hpp
+++ b/src/blu_cat/gra/destination_buffer.hpp
@@ -14,15 +14,15 @@
  * limitations under the License.
  */
 
-#ifndef CANDY_GEAR_BLUCAT_DESTINATION_BUFFER_H
-#define CANDY_GEAR_BLUCAT_DESTINATION_BUFFER_H 1
+#ifndef BLU_CAT_GRA_DESTINATION_BUFFER_H
+#define BLU_CAT_GRA_DESTINATION_BUFFER_H 1
 
 #include "base_buffer.hpp"
 #include "vulkan.hpp"
 #include "source_buffer.hpp"
 #include "queue_family.hpp"
 
-namespace BluCat
+namespace BluCat::GRA
 {
 
 struct DestinationBuffer: public BaseBuffer
@@ -51,4 +51,4 @@ struct DestinationBuffer: public BaseBuffer
 
 }
 
-#endif /* CANDY_GEAR_BLUCAT_DESTINATION_BUFFER_H */
+#endif /* BLU_CAT_GRA_DESTINATION_BUFFER_H */
diff --git a/src/blucat/device.cpp b/src/blu_cat/gra/device.cpp
index 8ce6d17..b2d114a 100644
--- a/src/blucat/device.cpp
+++ b/src/blu_cat/gra/device.cpp
@@ -23,7 +23,7 @@
 #include <sstream>
 #endif
 
-#include "core.hpp"
+#include "../int/core.hpp"
 
 namespace
 {
@@ -61,7 +61,7 @@ create_shader_module(VkDevice vk_device, const char *filename)
 }
 }
 
-namespace BluCat
+namespace BluCat::GRA
 {
 
 Device::Device(VkPhysicalDevice vk_physical_device, bool with_swapchain)
@@ -98,7 +98,7 @@ Device::Device(VkPhysicalDevice vk_physical_device, bool with_swapchain)
     message << "Device ID: " << physical_properties.deviceID << std::endl;
     message << "Device type: " << physical_properties.deviceType <<
       std::endl;
-    core.log.message(Log::Level::Trace, message.str());
+    BluCat::INT::core.log.message(Log::Level::Trace, message.str());
 #endif
 
     std::vector<VkDeviceQueueCreateInfo> device_queue_create_infos;
@@ -300,7 +300,8 @@ Device::Device(VkPhysicalDevice vk_physical_device, bool with_swapchain)
     // Select families with presentation support.
     VkBool32 present_supported;
     vkGetPhysicalDeviceSurfaceSupportKHR(
-      vk_physical_device, i, core.window_surface, &present_supported);
+      vk_physical_device, i, BluCat::INT::core.window_surface,
+			&present_supported);
     if(present_supported)
       this->queue_families_with_presentation.push_back(
 	&this->queue_families[i]);
@@ -371,7 +372,7 @@ Device::get_queue_family_with_graphics() const
   */
   std::uniform_int_distribution<std::size_t> random_distribution{
     0, this->queue_families_with_graphics.size() -1};
-  auto random = random_distribution(random_number_generator);
+  auto random = random_distribution(INT::random_number_generator);
   return this->queue_families_with_graphics[0];
 }
 
@@ -385,7 +386,7 @@ Device::get_queue_family_with_presentation() const
   */
   std::uniform_int_distribution<std::size_t> random_distribution{
     0, this->queue_families_with_presentation.size() -1};
-  auto random = random_distribution(random_number_generator);
+  auto random = random_distribution(INT::random_number_generator);
   return this->queue_families_with_presentation[0];
 }
 
diff --git a/src/blucat/device.hpp b/src/blu_cat/gra/device.hpp
index 61e87a4..fd53198 100644
--- a/src/blucat/device.hpp
+++ b/src/blu_cat/gra/device.hpp
@@ -14,8 +14,8 @@
  * limitations under the License.
  */
 
-#ifndef CANDY_GEAR_BLUCAT_DEVICE_H
-#define CANDY_GEAR_BLUCAT_DEVICE_H 1
+#ifndef BLU_CAT_GRA_DEVICE_H
+#define BLU_CAT_GRA_DEVICE_H 1
 
 #include <cstdlib>
 #include <vector>
@@ -23,7 +23,7 @@
 #include "vulkan.hpp"
 #include "queue_family.hpp"
 
-namespace BluCat
+namespace BluCat::GRA
 {
 
 struct Device
@@ -66,4 +66,4 @@ public:
 
 }
 
-#endif /* CANDY_GEAR_BLUCAT_DEVICE_H */
+#endif /* BLU_CAT_GRA_DEVICE_H */
diff --git a/src/blucat/font.cpp b/src/blu_cat/gra/font.cpp
index 603dda1..a9c2074 100644
--- a/src/blucat/font.cpp
+++ b/src/blu_cat/gra/font.cpp
@@ -16,15 +16,16 @@
 
 #include "font.hpp"
 
-#include "core.hpp"
+#include "../int/core.hpp"
 
-namespace BluCat
+namespace BluCat::GRA
 {
 
 Font::Font(const char* font_path, int font_size)
 {
   FT_Error error;
-  error = FT_New_Face(core.font_library, font_path, 0, &this->face);
+  error = FT_New_Face(
+		BluCat::INT::core.font_library, font_path, 0, &this->face);
   if(error == FT_Err_Unknown_File_Format) throw std::invalid_argument(
     "The font file could be opened and read, but it appears that its font "
     "format is unsupported.");
diff --git a/src/blucat/font.hpp b/src/blu_cat/gra/font.hpp
index 1b9be69..72ec6d3 100644
--- a/src/blucat/font.hpp
+++ b/src/blu_cat/gra/font.hpp
@@ -14,15 +14,15 @@
  * limitations under the License.
  */
 
-#ifndef CANDY_GEAR_BLUCAT_FONT_H
-#define CANDY_GEAR_BLUCAT_FONT_H 1
+#ifndef BLU_CAT_GRA_FONT_H
+#define BLU_CAT_GRA_FONT_H 1
 
 #include <memory>
 #include <unordered_map>
 
 #include "character.hpp"
 
-namespace BluCat
+namespace BluCat::GRA
 {
 
 struct Font
@@ -39,4 +39,4 @@ struct Font
 
 }
 
-#endif /* CANDY_GEAR_BLUCAT_FONT_H */
+#endif /* BLU_CAT_GRA_FONT_H */
diff --git a/src/blucat/framebuffer.cpp b/src/blu_cat/gra/framebuffer.cpp
index c4d3230..e2d0b7c 100644
--- a/src/blucat/framebuffer.cpp
+++ b/src/blu_cat/gra/framebuffer.cpp
@@ -16,8 +16,8 @@
 
 #include "framebuffer.hpp"
 
-#include "command.hpp"
-#include "core.hpp"
+#include "../com/command.hpp"
+#include "../int/core.hpp"
 #include "image.hpp"
 
 namespace
@@ -25,17 +25,17 @@ namespace
 void
 load_depth_image(void *obj)
 {
-  auto self = static_cast<BluCat::Framebuffer*>(obj);
+  auto self = static_cast<BluCat::GRA::Framebuffer*>(obj);
 
   VkExtent3D extent3d{};
-  extent3d.width = BluCat::core.display_width;
-  extent3d.height = BluCat::core.display_height;
+  extent3d.width = BluCat::INT::core.display_width;
+  extent3d.height = BluCat::INT::core.display_height;
   extent3d.depth = 1;
 
   try
   {
-    BluCat::Image::create(
-      BluCat::core.vk_device_with_swapchain,
+    BluCat::GRA::Image::create(
+      BluCat::INT::core.vk_device_with_swapchain,
       &self->depth_image,
       &self->depth_image_memory,
       VK_FORMAT_D32_SFLOAT,
@@ -45,7 +45,7 @@ load_depth_image(void *obj)
       VK_IMAGE_USAGE_DEPTH_STENCIL_ATTACHMENT_BIT
       );
   }
-  catch(BluCat::Image::Error error)
+  catch(BluCat::GRA::Image::Error error)
   {
     std::string error_message{"Failed to create depth image → "};
     error_message += error.what();
@@ -56,29 +56,29 @@ load_depth_image(void *obj)
 void
 unload_depth_image(void *obj)
 {
-  auto self = static_cast<BluCat::Framebuffer*>(obj);
+  auto self = static_cast<BluCat::GRA::Framebuffer*>(obj);
 
   vkDestroyImage(
-    BluCat::core.vk_device_with_swapchain->device, self->depth_image,
+    BluCat::INT::core.vk_device_with_swapchain->device, self->depth_image,
     nullptr);
   vkFreeMemory(
-    BluCat::core.vk_device_with_swapchain->device,
+    BluCat::INT::core.vk_device_with_swapchain->device,
     self->depth_image_memory, nullptr);
 }
 
 void
 load_depth_image_view(void *obj)
 {
-  auto self = static_cast<BluCat::Framebuffer*>(obj);
+  auto self = static_cast<BluCat::GRA::Framebuffer*>(obj);
 
   try
   {
-    BluCat::Image::create_view(
-      BluCat::core.vk_device_with_swapchain, &self->depth_image_view,
+    BluCat::GRA::Image::create_view(
+      BluCat::INT::core.vk_device_with_swapchain, &self->depth_image_view,
       self->depth_image,
       VK_FORMAT_D32_SFLOAT, VK_IMAGE_ASPECT_DEPTH_BIT);
   }
-  catch(BluCat::Image::Error error)
+  catch(BluCat::GRA::Image::Error error)
   {
     std::string error_message{"Failed to create depth image view → "};
     error_message += error.what();
@@ -89,38 +89,38 @@ load_depth_image_view(void *obj)
 void
 unload_depth_image_view(void *obj)
 {
-  auto self = static_cast<BluCat::Framebuffer*>(obj);
+  auto self = static_cast<BluCat::GRA::Framebuffer*>(obj);
 
   vkDestroyImageView(
-    BluCat::core.vk_device_with_swapchain->device, self->depth_image_view,
+    BluCat::INT::core.vk_device_with_swapchain->device, self->depth_image_view,
 		nullptr);
 }
 
 void
 load_3d(void *obj)
 {
-  auto self = static_cast<BluCat::Framebuffer*>(obj);
+  auto self = static_cast<BluCat::GRA::Framebuffer*>(obj);
 
-  self->pipeline_3d.resize(BluCat::core.vk_swapchain->images_count);
-  for (auto i{0}; i < BluCat::core.vk_swapchain->images_count; i++)
+  self->pipeline_3d.resize(BluCat::INT::core.vk_swapchain->images_count);
+  for (auto i{0}; i < BluCat::INT::core.vk_swapchain->images_count; i++)
   {
     std::array<VkImageView, 2> attachments = {
-      BluCat::core.vk_swapchain->image_views[i],
+      BluCat::INT::core.vk_swapchain->image_views[i],
       self->depth_image_view
     };
 
     VkFramebufferCreateInfo framebuffer_info{};
     framebuffer_info.sType = VK_STRUCTURE_TYPE_FRAMEBUFFER_CREATE_INFO;
-    framebuffer_info.renderPass = BluCat::core.vk_render_pass->pipeline_3d;
+    framebuffer_info.renderPass = BluCat::INT::core.vk_render_pass->pipeline_3d;
     framebuffer_info.attachmentCount = attachments.size();
     framebuffer_info.pAttachments = attachments.data();
-    framebuffer_info.width = BluCat::core.display_width;
-    framebuffer_info.height = BluCat::core.display_height;
+    framebuffer_info.width = BluCat::INT::core.display_width;
+    framebuffer_info.height = BluCat::INT::core.display_height;
 
     framebuffer_info.layers = 1;
 
     if(vkCreateFramebuffer(
-	 BluCat::core.vk_device_with_swapchain->device, &framebuffer_info, nullptr,
+	 BluCat::INT::core.vk_device_with_swapchain->device, &framebuffer_info, nullptr,
 	 &self->pipeline_3d[i]) != VK_SUCCESS)
       throw CommandError{"Failed to create Vulkan Framebuffer."};
   }
@@ -129,36 +129,36 @@ load_3d(void *obj)
 void
 unload_3d(void *obj)
 {
-  auto self = static_cast<BluCat::Framebuffer*>(obj);
+  auto self = static_cast<BluCat::GRA::Framebuffer*>(obj);
 
   for(auto framebuffer: self->pipeline_3d)
     vkDestroyFramebuffer(
-      BluCat::core.vk_device_with_swapchain->device, framebuffer, nullptr);
+      BluCat::INT::core.vk_device_with_swapchain->device, framebuffer, nullptr);
 }
 
 void
 load_2d(void *obj)
 {
-  auto self = static_cast<BluCat::Framebuffer*>(obj);
+  auto self = static_cast<BluCat::GRA::Framebuffer*>(obj);
 
-  self->pipeline_2d.resize(BluCat::core.vk_swapchain->images_count);
-  for (auto i{0}; i < BluCat::core.vk_swapchain->images_count; i++)
+  self->pipeline_2d.resize(BluCat::INT::core.vk_swapchain->images_count);
+  for (auto i{0}; i < BluCat::INT::core.vk_swapchain->images_count; i++)
   {
     std::array<VkImageView, 1> attachments = {
-      BluCat::core.vk_swapchain->image_views[i]
+      BluCat::INT::core.vk_swapchain->image_views[i]
     };
 
     VkFramebufferCreateInfo framebuffer_info{};
     framebuffer_info.sType = VK_STRUCTURE_TYPE_FRAMEBUFFER_CREATE_INFO;
-    framebuffer_info.renderPass = BluCat::core.vk_render_pass->pipeline_2d;
+    framebuffer_info.renderPass = BluCat::INT::core.vk_render_pass->pipeline_2d;
     framebuffer_info.attachmentCount = attachments.size();
     framebuffer_info.pAttachments = attachments.data();
-    framebuffer_info.width = BluCat::core.display_width;
-    framebuffer_info.height = BluCat::core.display_height;
+    framebuffer_info.width = BluCat::INT::core.display_width;
+    framebuffer_info.height = BluCat::INT::core.display_height;
     framebuffer_info.layers = 1;
 
     if(vkCreateFramebuffer(
-         BluCat::core.vk_device_with_swapchain->device, &framebuffer_info,
+         BluCat::INT::core.vk_device_with_swapchain->device, &framebuffer_info,
 				 nullptr, &self->pipeline_2d[i])
        != VK_SUCCESS)
       throw CommandError{"Failed to create Vulkan Framebuffer."};
@@ -168,11 +168,11 @@ load_2d(void *obj)
 void
 unload_2d(void *obj)
 {
-  auto self = static_cast<BluCat::Framebuffer*>(obj);
+  auto self = static_cast<BluCat::GRA::Framebuffer*>(obj);
 
   for(auto framebuffer: self->pipeline_2d)
     vkDestroyFramebuffer(
-      BluCat::core.vk_device_with_swapchain->device, framebuffer, nullptr);
+      BluCat::INT::core.vk_device_with_swapchain->device, framebuffer, nullptr);
 }
 
 const CommandChain loader{
@@ -184,7 +184,7 @@ const CommandChain loader{
 
 }
 
-namespace BluCat
+namespace BluCat::GRA
 {
 
 Framebuffer::Framebuffer()
diff --git a/src/blucat/framebuffer.hpp b/src/blu_cat/gra/framebuffer.hpp
index e9303f8..ddbf5c4 100644
--- a/src/blucat/framebuffer.hpp
+++ b/src/blu_cat/gra/framebuffer.hpp
@@ -14,14 +14,14 @@
  * limitations under the License.
  */
 
-#ifndef CANDY_GEAR_BLUCAT_FRAMEBUFFER_H
-#define CANDY_GEAR_BLUCAT_FRAMEBUFFER_H 1
+#ifndef BLU_CAT_GRA_FRAMEBUFFER_H
+#define BLU_CAT_GRA_FRAMEBUFFER_H 1
 
 #include <vector>
 
 #include "vulkan.hpp"
 
-namespace BluCat
+namespace BluCat::GRA
 {
 
 struct Framebuffer
@@ -40,4 +40,4 @@ struct Framebuffer
 
 }
 
-#endif /* CANDY_GEAR_BLUCAT_FRAMEBUFFER_H */
+#endif /* BLU_CAT_GRA_FRAMEBUFFER_H */
diff --git a/src/blucat/graphics_pipeline_2d_solid.cpp b/src/blu_cat/gra/graphics_pipeline_2d_solid.cpp
index afd8a2e..7acca09 100644
--- a/src/blucat/graphics_pipeline_2d_solid.cpp
+++ b/src/blu_cat/gra/graphics_pipeline_2d_solid.cpp
@@ -18,7 +18,7 @@
 
 #include <array>
 
-#include "core.hpp"
+#include "../int/core.hpp"
 #include "sprite.hpp"
 #include "uniform_data_object.hpp"
 
@@ -28,7 +28,7 @@ namespace
 void
 load_pipeline(void *obj)
 {
-  auto self = static_cast<BluCat::GraphicsPipeline2DSolid*>(obj);
+  auto self = static_cast<BluCat::GRA::GraphicsPipeline2DSolid*>(obj);
 
   VkPipelineShaderStageCreateInfo vert_shader_stage_info{};
   vert_shader_stage_info.sType =
@@ -37,7 +37,7 @@ load_pipeline(void *obj)
   vert_shader_stage_info.flags = 0;
   vert_shader_stage_info.stage = VK_SHADER_STAGE_VERTEX_BIT;
   vert_shader_stage_info.module =
-    BluCat::core.vk_device_with_swapchain->vert2d_solid_shader_module;
+    BluCat::INT::core.vk_device_with_swapchain->vert2d_solid_shader_module;
   vert_shader_stage_info.pName = "main";
   vert_shader_stage_info.pSpecializationInfo = nullptr;
 
@@ -48,7 +48,7 @@ load_pipeline(void *obj)
   frag_shader_stage_info.flags = 0;
   frag_shader_stage_info.stage = VK_SHADER_STAGE_FRAGMENT_BIT;
   frag_shader_stage_info.module =
-    BluCat::core.vk_device_with_swapchain->frag2d_solid_shader_module;
+    BluCat::INT::core.vk_device_with_swapchain->frag2d_solid_shader_module;
   frag_shader_stage_info.pName = "main";
   frag_shader_stage_info.pSpecializationInfo = nullptr;
 
@@ -91,14 +91,14 @@ load_pipeline(void *obj)
   VkViewport viewport = {};
   viewport.x = 0;
   viewport.y = 0;
-  viewport.width = BluCat::core.display_width;
-  viewport.height = BluCat::core.display_height;
+  viewport.width = BluCat::INT::core.display_width;
+  viewport.height = BluCat::INT::core.display_height;
   viewport.minDepth = 0.0f;
   viewport.maxDepth = 1.0f;
 
   VkRect2D scissor = {};
   scissor.offset = {0, 0};
-  scissor.extent = {BluCat::core.display_width, BluCat::core.display_height};
+  scissor.extent = {BluCat::INT::core.display_width, BluCat::INT::core.display_height};
 
   VkPipelineViewportStateCreateInfo viewport_state = {};
   viewport_state.sType =
@@ -191,14 +191,14 @@ load_pipeline(void *obj)
   pipeline_info.pColorBlendState = &color_blending;
   pipeline_info.pDynamicState = &dynamic_state_info;
   pipeline_info.layout =
-    BluCat::core.vk_graphics_pipeline_2d_solid_layout->pipeline;
-  pipeline_info.renderPass = BluCat::core.vk_render_pass->pipeline_2d;
+    BluCat::INT::core.vk_graphics_pipeline_2d_solid_layout->pipeline;
+  pipeline_info.renderPass = BluCat::INT::core.vk_render_pass->pipeline_2d;
   pipeline_info.subpass = 0;
   pipeline_info.basePipelineHandle = VK_NULL_HANDLE;
   pipeline_info.basePipelineIndex = -1;
 
   if(vkCreateGraphicsPipelines(
-       BluCat::core.vk_device_with_swapchain->device, VK_NULL_HANDLE, 1,
+       BluCat::INT::core.vk_device_with_swapchain->device, VK_NULL_HANDLE, 1,
        &pipeline_info, nullptr, &self->graphic_pipeline)
      != VK_SUCCESS)
     throw CommandError{"Failed to create graphics pipeline."};
@@ -207,10 +207,10 @@ load_pipeline(void *obj)
 void
 unload_pipeline(void *obj)
 {
-  auto self = static_cast<BluCat::GraphicsPipeline2DSolid*>(obj);
+  auto self = static_cast<BluCat::GRA::GraphicsPipeline2DSolid*>(obj);
 
   vkDestroyPipeline(
-    BluCat::core.vk_device_with_swapchain->device, self->graphic_pipeline,
+    BluCat::INT::core.vk_device_with_swapchain->device, self->graphic_pipeline,
 		nullptr);
 }
 
@@ -220,7 +220,7 @@ const CommandChain loader{
 
 }
 
-namespace BluCat
+namespace BluCat::GRA
 {
 
 GraphicsPipeline2DSolid::GraphicsPipeline2DSolid()
@@ -277,7 +277,7 @@ GraphicsPipeline2DSolid::draw(
 
     vkCmdBindDescriptorSets(
       draw_command_buffer, VK_PIPELINE_BIND_POINT_GRAPHICS,
-      core.vk_graphics_pipeline_2d_solid_layout->pipeline, 0,
+      INT::core.vk_graphics_pipeline_2d_solid_layout->pipeline, 0,
       vk_descriptor_sets.size(), vk_descriptor_sets.data(), 0, nullptr);
     vkCmdBindVertexBuffers(
       draw_command_buffer, 0, 1, &sprite_to_draw.sprite->vertex_buffer->buffer,
@@ -286,7 +286,7 @@ GraphicsPipeline2DSolid::draw(
     UDOVector4D position{sprite_to_draw.position};
     vkCmdPushConstants(
       draw_command_buffer,
-      core.vk_graphics_pipeline_2d_solid_layout->pipeline,
+      INT::core.vk_graphics_pipeline_2d_solid_layout->pipeline,
       VK_SHADER_STAGE_VERTEX_BIT, 0, sizeof(UDOVector4D), &position);
     vkCmdDraw(draw_command_buffer, Sprite::vertex_count, 1, 0, 0);
   }
diff --git a/src/blucat/graphics_pipeline_2d_solid.hpp b/src/blu_cat/gra/graphics_pipeline_2d_solid.hpp
index 753e9d8..c1520c2 100644
--- a/src/blucat/graphics_pipeline_2d_solid.hpp
+++ b/src/blu_cat/gra/graphics_pipeline_2d_solid.hpp
@@ -14,8 +14,8 @@
  * limitations under the License.
  */
 
-#ifndef CANDY_GEAR_BLUCAT_GRAPHICS_PIPELINE_2D_SOLID_H
-#define CANDY_GEAR_BLUCAT_GRAPHICS_PIPELINE_2D_SOLID_H 1
+#ifndef BLU_CAT_GRA_GRAPHICS_PIPELINE_2D_SOLID_H
+#define BLU_CAT_GRA_GRAPHICS_PIPELINE_2D_SOLID_H 1
 
 #include <memory>
 
@@ -23,7 +23,7 @@
 #include "command_pool.hpp"
 #include "view_2d.hpp"
 
-namespace BluCat
+namespace BluCat::GRA
 {
 
 struct GraphicsPipeline2DSolid
@@ -41,4 +41,4 @@ struct GraphicsPipeline2DSolid
 
 }
 
-#endif /* CANDY_GEAR_BLUCAT_GRAPHICS_PIPELINE_2D_SOLID_H */
+#endif /* BLU_CAT_GRA_GRAPHICS_PIPELINE_2D_SOLID_H */
diff --git a/src/blucat/graphics_pipeline_2d_solid_layout.cpp b/src/blu_cat/gra/graphics_pipeline_2d_solid_layout.cpp
index 666556d..476bac1 100644
--- a/src/blucat/graphics_pipeline_2d_solid_layout.cpp
+++ b/src/blu_cat/gra/graphics_pipeline_2d_solid_layout.cpp
@@ -18,7 +18,7 @@
 
 #include <array>
 
-#include "core.hpp"
+#include "../int/core.hpp"
 #include "uniform_data_object.hpp"
 
 namespace
@@ -27,17 +27,17 @@ namespace
 void
 load_pipeline(void *obj)
 {
-  auto self = static_cast<BluCat::GraphicsPipeline2DSolidLayout*>(obj);
+  auto self = static_cast<BluCat::GRA::GraphicsPipeline2DSolidLayout*>(obj);
 
   std::array<VkDescriptorSetLayout, 2> set_layouts{
-    BluCat::core.vk_descriptor_set_layout->view,
-    BluCat::core.vk_descriptor_set_layout->texture
+    BluCat::INT::core.vk_descriptor_set_layout->view,
+    BluCat::INT::core.vk_descriptor_set_layout->texture
   };
 
   std::array<VkPushConstantRange, 1> push_constants;
   push_constants[0].stageFlags = VK_SHADER_STAGE_VERTEX_BIT;
   push_constants[0].offset = 0;
-  push_constants[0].size = sizeof(BluCat::UDOVector4D);
+  push_constants[0].size = sizeof(BluCat::GRA::UDOVector4D);
 
   VkPipelineLayoutCreateInfo pipeline_layout_info{};
   pipeline_layout_info.sType = VK_STRUCTURE_TYPE_PIPELINE_LAYOUT_CREATE_INFO;
@@ -47,7 +47,7 @@ load_pipeline(void *obj)
   pipeline_layout_info.pPushConstantRanges = push_constants.data();
 
   if(vkCreatePipelineLayout(
-       BluCat::core.vk_device_with_swapchain->device, &pipeline_layout_info,
+       BluCat::INT::core.vk_device_with_swapchain->device, &pipeline_layout_info,
        nullptr, &self->pipeline) != VK_SUCCESS)
     throw CommandError{"Failed to create Vulkan pipeline layout."};
 }
@@ -55,10 +55,10 @@ load_pipeline(void *obj)
 void
 unload_pipeline(void *obj)
 {
-  auto self = static_cast<BluCat::GraphicsPipeline2DSolidLayout*>(obj);
+  auto self = static_cast<BluCat::GRA::GraphicsPipeline2DSolidLayout*>(obj);
 
   vkDestroyPipelineLayout(
-    BluCat::core.vk_device_with_swapchain->device, self->pipeline, nullptr);
+    BluCat::INT::core.vk_device_with_swapchain->device, self->pipeline, nullptr);
 }
 
 const CommandChain loader{
@@ -67,7 +67,7 @@ const CommandChain loader{
 
 }
 
-namespace BluCat
+namespace BluCat::GRA
 {
 
 GraphicsPipeline2DSolidLayout::GraphicsPipeline2DSolidLayout()
diff --git a/src/blucat/graphics_pipeline_2d_solid_layout.hpp b/src/blu_cat/gra/graphics_pipeline_2d_solid_layout.hpp
index f6a8960..6abd65d 100644
--- a/src/blucat/graphics_pipeline_2d_solid_layout.hpp
+++ b/src/blu_cat/gra/graphics_pipeline_2d_solid_layout.hpp
@@ -14,12 +14,12 @@
  * limitations under the License.
  */
 
-#ifndef CANDY_GEAR_BLUCAT_GRAPHICS_PIPELINE_2D_LAYOUT_H
-#define CANDY_GEAR_BLUCAT_GRAPHICS_PIPELINE_2D_LAYOUT_H 1
+#ifndef BLU_CAT_GRA_GRAPHICS_PIPELINE_2D_LAYOUT_H
+#define BLU_CAT_GRA_GRAPHICS_PIPELINE_2D_LAYOUT_H 1
 
 #include "vulkan.hpp"
 
-namespace BluCat
+namespace BluCat::GRA
 {
 
 struct GraphicsPipeline2DSolidLayout
@@ -32,4 +32,4 @@ struct GraphicsPipeline2DSolidLayout
 
 }
 
-#endif /* CANDY_GEAR_BLUCAT_GRAPHICS_PIPELINE_2D_LAYOUT_H */
+#endif /* BLU_CAT_GRA_GRAPHICS_PIPELINE_2D_LAYOUT_H */
diff --git a/src/blucat/graphics_pipeline_2d_wired.cpp b/src/blu_cat/gra/graphics_pipeline_2d_wired.cpp
index 9cd3a86..20491ed 100644
--- a/src/blucat/graphics_pipeline_2d_wired.cpp
+++ b/src/blu_cat/gra/graphics_pipeline_2d_wired.cpp
@@ -18,7 +18,7 @@
 
 #include <array>
 
-#include "core.hpp"
+#include "../int/core.hpp"
 #include "rectangle.hpp"
 #include "sprite.hpp"
 #include "uniform_data_object.hpp"
@@ -29,17 +29,17 @@ namespace
 void
 load_indexes(void *obj)
 {
-  auto self = static_cast<BluCat::GraphicsPipeline2DWired*>(obj);
+  auto self = static_cast<BluCat::GRA::GraphicsPipeline2DWired*>(obj);
 
   self->queue_family =
-    BluCat::core.vk_device_with_swapchain->get_queue_family_with_graphics();
+    BluCat::INT::core.vk_device_with_swapchain->get_queue_family_with_graphics();
 
   std::array<uint32_t, 4> indexes{0, 1, 2, 3};
   void *indexes_data{indexes.data()};
   size_t indexes_size{sizeof(indexes[0]) * indexes.size()};
-  BluCat::SourceBuffer source_index_buffer{
+  BluCat::GRA::SourceBuffer source_index_buffer{
     self->queue_family->device, indexes_data, indexes_size};
-  self->index_buffer = new BluCat::DestinationBuffer{
+  self->index_buffer = new BluCat::GRA::DestinationBuffer{
     self->queue_family, &source_index_buffer,
     VK_BUFFER_USAGE_INDEX_BUFFER_BIT};
 }
@@ -47,7 +47,7 @@ load_indexes(void *obj)
 void
 unload_indexes(void *obj)
 {
-  auto self = static_cast<BluCat::GraphicsPipeline2DWired*>(obj);
+  auto self = static_cast<BluCat::GRA::GraphicsPipeline2DWired*>(obj);
 
   delete self->index_buffer;
 }
@@ -55,7 +55,7 @@ unload_indexes(void *obj)
 void
 load_pipeline(void *obj)
 {
-  auto self = static_cast<BluCat::GraphicsPipeline2DWired*>(obj);
+  auto self = static_cast<BluCat::GRA::GraphicsPipeline2DWired*>(obj);
 
   VkPipelineShaderStageCreateInfo vert_shader_stage_info{};
   vert_shader_stage_info.sType =
@@ -64,7 +64,7 @@ load_pipeline(void *obj)
   vert_shader_stage_info.flags = 0;
   vert_shader_stage_info.stage = VK_SHADER_STAGE_VERTEX_BIT;
   vert_shader_stage_info.module =
-    BluCat::core.vk_device_with_swapchain->vert2d_wired_shader_module;
+    BluCat::INT::core.vk_device_with_swapchain->vert2d_wired_shader_module;
   vert_shader_stage_info.pName = "main";
   vert_shader_stage_info.pSpecializationInfo = nullptr;
 
@@ -75,7 +75,7 @@ load_pipeline(void *obj)
   frag_shader_stage_info.flags = 0;
   frag_shader_stage_info.stage = VK_SHADER_STAGE_FRAGMENT_BIT;
   frag_shader_stage_info.module =
-    BluCat::core.vk_device_with_swapchain->frag2d_wired_shader_module;
+    BluCat::INT::core.vk_device_with_swapchain->frag2d_wired_shader_module;
   frag_shader_stage_info.pName = "main";
   frag_shader_stage_info.pSpecializationInfo = nullptr;
 
@@ -105,14 +105,14 @@ load_pipeline(void *obj)
   VkViewport viewport = {};
   viewport.x = 0;
   viewport.y = 0;
-  viewport.width = BluCat::core.display_width;
-  viewport.height = BluCat::core.display_height;
+  viewport.width = BluCat::INT::core.display_width;
+  viewport.height = BluCat::INT::core.display_height;
   viewport.minDepth = 0.0f;
   viewport.maxDepth = 1.0f;
 
   VkRect2D scissor = {};
   scissor.offset = {0, 0};
-  scissor.extent = {BluCat::core.display_width, BluCat::core.display_height};
+  scissor.extent = {BluCat::INT::core.display_width, BluCat::INT::core.display_height};
 
   VkPipelineViewportStateCreateInfo viewport_state = {};
   viewport_state.sType =
@@ -203,14 +203,14 @@ load_pipeline(void *obj)
   pipeline_info.pColorBlendState = &color_blending;
   pipeline_info.pDynamicState = &dynamic_state_info;
   pipeline_info.layout =
-    BluCat::core.vk_graphics_pipeline_2d_wired_layout->pipeline;
-  pipeline_info.renderPass = BluCat::core.vk_render_pass->pipeline_2d;
+    BluCat::INT::core.vk_graphics_pipeline_2d_wired_layout->pipeline;
+  pipeline_info.renderPass = BluCat::INT::core.vk_render_pass->pipeline_2d;
   pipeline_info.subpass = 0;
   pipeline_info.basePipelineHandle = VK_NULL_HANDLE;
   pipeline_info.basePipelineIndex = -1;
 
   if(vkCreateGraphicsPipelines(
-       BluCat::core.vk_device_with_swapchain->device, VK_NULL_HANDLE, 1,
+       BluCat::INT::core.vk_device_with_swapchain->device, VK_NULL_HANDLE, 1,
        &pipeline_info, nullptr, &self->graphic_pipeline) != VK_SUCCESS)
     throw CommandError{"Failed to create graphics pipeline."};
 }
@@ -218,10 +218,10 @@ load_pipeline(void *obj)
 void
 unload_pipeline(void *obj)
 {
-  auto self = static_cast<BluCat::GraphicsPipeline2DWired*>(obj);
+  auto self = static_cast<BluCat::GRA::GraphicsPipeline2DWired*>(obj);
 
   vkDestroyPipeline(
-    BluCat::core.vk_device_with_swapchain->device, self->graphic_pipeline,
+    BluCat::INT::core.vk_device_with_swapchain->device, self->graphic_pipeline,
 		nullptr);
 }
 
@@ -232,7 +232,7 @@ const CommandChain loader{
 
 }
 
-namespace BluCat
+namespace BluCat::GRA
 {
 
 GraphicsPipeline2DWired::GraphicsPipeline2DWired()
@@ -278,7 +278,7 @@ GraphicsPipeline2DWired::draw(
 
     vkCmdBindDescriptorSets(
       draw_command_buffer, VK_PIPELINE_BIND_POINT_GRAPHICS,
-      core.vk_graphics_pipeline_2d_wired_layout->pipeline, 0,
+      INT::core.vk_graphics_pipeline_2d_wired_layout->pipeline, 0,
       vk_descriptor_sets.size(), vk_descriptor_sets.data(), 0, nullptr);
     vkCmdBindPipeline(
       draw_command_buffer, VK_PIPELINE_BIND_POINT_GRAPHICS,
@@ -295,11 +295,11 @@ GraphicsPipeline2DWired::draw(
       UDOVector3D color{rect.color};
       vkCmdPushConstants(
         draw_command_buffer,
-        core.vk_graphics_pipeline_2d_wired_layout->pipeline,
+        INT::core.vk_graphics_pipeline_2d_wired_layout->pipeline,
         VK_SHADER_STAGE_VERTEX_BIT, 0, sizeof(UDOVector4D), &position);
       vkCmdPushConstants(
         draw_command_buffer,
-        core.vk_graphics_pipeline_2d_wired_layout->pipeline,
+        INT::core.vk_graphics_pipeline_2d_wired_layout->pipeline,
         VK_SHADER_STAGE_FRAGMENT_BIT, sizeof(UDOVector4D), sizeof(UDOVector3D),
         &color);
       vkCmdDrawIndexed(
diff --git a/src/blucat/graphics_pipeline_2d_wired.hpp b/src/blu_cat/gra/graphics_pipeline_2d_wired.hpp
index a351aee..7d2752e 100644
--- a/src/blucat/graphics_pipeline_2d_wired.hpp
+++ b/src/blu_cat/gra/graphics_pipeline_2d_wired.hpp
@@ -14,15 +14,15 @@
  * limitations under the License.
  */
 
-#ifndef CANDY_GEAR_BLUCAT_GRAPHICS_PIPELINE_2D_WIRED_H
-#define CANDY_GEAR_BLUCAT_GRAPHICS_PIPELINE_2D_WIRED_H 1
+#ifndef BLU_CAT_GRA_GRAPHICS_PIPELINE_2D_WIRED_H
+#define BLU_CAT_GRA_GRAPHICS_PIPELINE_2D_WIRED_H 1
 
 #include <memory>
 
 #include "vulkan.hpp"
 #include "view_2d.hpp"
 
-namespace BluCat
+namespace BluCat::GRA
 {
 
 struct GraphicsPipeline2DWired
@@ -44,4 +44,4 @@ struct GraphicsPipeline2DWired
 
 }
 
-#endif /* CANDY_GEAR_BLUCAT_GRAPHICS_PIPELINE_2D_WIRED_H */
+#endif /* BLU_CAT_GRA_GRAPHICS_PIPELINE_2D_WIRED_H */
diff --git a/src/blucat/graphics_pipeline_2d_wired_layout.cpp b/src/blu_cat/gra/graphics_pipeline_2d_wired_layout.cpp
index 104c599..431a845 100644
--- a/src/blucat/graphics_pipeline_2d_wired_layout.cpp
+++ b/src/blu_cat/gra/graphics_pipeline_2d_wired_layout.cpp
@@ -18,7 +18,7 @@
 
 #include <array>
 
-#include "core.hpp"
+#include "../int/core.hpp"
 #include "graphics_pipeline_2d_solid_layout.hpp"
 #include "uniform_data_object.hpp"
 
@@ -28,20 +28,20 @@ namespace
 void
 load_pipeline(void *obj)
 {
-  auto self = static_cast<BluCat::GraphicsPipeline2DWiredLayout*>(obj);
+  auto self = static_cast<BluCat::GRA::GraphicsPipeline2DWiredLayout*>(obj);
 
   std::array<VkDescriptorSetLayout, 1> set_layouts{
-    BluCat::core.vk_descriptor_set_layout->view
+    BluCat::INT::core.vk_descriptor_set_layout->view
   };
 
   std::array<VkPushConstantRange, 2> push_constants;
   push_constants[0].stageFlags = VK_SHADER_STAGE_VERTEX_BIT;
   push_constants[0].offset = 0;
-  push_constants[0].size = sizeof(BluCat::UDOVector4D);
+  push_constants[0].size = sizeof(BluCat::GRA::UDOVector4D);
 
   push_constants[1].stageFlags = VK_SHADER_STAGE_FRAGMENT_BIT;
-  push_constants[1].offset = sizeof(BluCat::UDOVector4D);
-  push_constants[1].size = sizeof(BluCat::UDOVector3D);
+  push_constants[1].offset = sizeof(BluCat::GRA::UDOVector4D);
+  push_constants[1].size = sizeof(BluCat::GRA::UDOVector3D);
 
   VkPipelineLayoutCreateInfo pipeline_layout_info{};
   pipeline_layout_info.sType = VK_STRUCTURE_TYPE_PIPELINE_LAYOUT_CREATE_INFO;
@@ -51,7 +51,7 @@ load_pipeline(void *obj)
   pipeline_layout_info.pPushConstantRanges = push_constants.data();
 
   if(vkCreatePipelineLayout(
-       BluCat::core.vk_device_with_swapchain->device, &pipeline_layout_info,
+       BluCat::INT::core.vk_device_with_swapchain->device, &pipeline_layout_info,
        nullptr, &self->pipeline) != VK_SUCCESS)
     throw CommandError{"Failed to create Vulkan pipeline layout."};
 }
@@ -59,10 +59,10 @@ load_pipeline(void *obj)
 void
 unload_pipeline(void *obj)
 {
-  auto self = static_cast<BluCat::GraphicsPipeline2DWiredLayout*>(obj);
+  auto self = static_cast<BluCat::GRA::GraphicsPipeline2DWiredLayout*>(obj);
 
   vkDestroyPipelineLayout(
-    BluCat::core.vk_device_with_swapchain->device, self->pipeline, nullptr);
+    BluCat::INT::core.vk_device_with_swapchain->device, self->pipeline, nullptr);
 }
 
 const CommandChain loader{
@@ -71,7 +71,7 @@ const CommandChain loader{
 
 }
 
-namespace BluCat
+namespace BluCat::GRA
 {
 
 GraphicsPipeline2DWiredLayout::GraphicsPipeline2DWiredLayout()
diff --git a/src/blucat/graphics_pipeline_2d_wired_layout.hpp b/src/blu_cat/gra/graphics_pipeline_2d_wired_layout.hpp
index 402e7dc..16f23ea 100644
--- a/src/blucat/graphics_pipeline_2d_wired_layout.hpp
+++ b/src/blu_cat/gra/graphics_pipeline_2d_wired_layout.hpp
@@ -14,12 +14,12 @@
  * limitations under the License.
  */
 
-#ifndef CANDY_GEAR_BLUCAT_GRAPHICS_PIPELINE_2D_WIRED_LAYOUT_H
-#define CANDY_GEAR_BLUCAT_GRAPHICS_PIPELINE_2D_WIRED_LAYOUT_H 1
+#ifndef BLU_CAT_GRA_GRAPHICS_PIPELINE_2D_WIRED_LAYOUT_H
+#define BLU_CAT_GRA_GRAPHICS_PIPELINE_2D_WIRED_LAYOUT_H 1
 
 #include "vulkan.hpp"
 
-namespace BluCat
+namespace BluCat::GRA
 {
 
 struct GraphicsPipeline2DWiredLayout
@@ -32,4 +32,4 @@ struct GraphicsPipeline2DWiredLayout
 
 }
 
-#endif /* CANDY_GEAR_BLUCAT_GRAPHICS_PIPELINE_2D_LAYOUT_H */
+#endif /* BLU_CAT_GRA_GRAPHICS_PIPELINE_2D_LAYOUT_H */
diff --git a/src/blucat/graphics_pipeline_3d.cpp b/src/blu_cat/gra/graphics_pipeline_3d.cpp
index bd64ebc..1f7324a 100644
--- a/src/blucat/graphics_pipeline_3d.cpp
+++ b/src/blu_cat/gra/graphics_pipeline_3d.cpp
@@ -19,7 +19,7 @@
 #include <array>
 #include <stdexcept>
 
-#include "core.hpp"
+#include "../int/core.hpp"
 #include "vulkan.hpp"
 #include "static_mesh_vertex.hpp"
 #include "uniform_data_object.hpp"
@@ -30,7 +30,7 @@ namespace
 void
 load_pipeline(void *obj)
 {
-  auto self = static_cast<BluCat::GraphicsPipeline3D*>(obj);
+  auto self = static_cast<BluCat::GRA::GraphicsPipeline3D*>(obj);
 
   VkPipelineShaderStageCreateInfo vert_shader_stage_info = {};
   vert_shader_stage_info.sType =
@@ -39,7 +39,7 @@ load_pipeline(void *obj)
   vert_shader_stage_info.flags = 0;
   vert_shader_stage_info.stage = VK_SHADER_STAGE_VERTEX_BIT;
   vert_shader_stage_info.module =
-    BluCat::core.vk_device_with_swapchain->vert3d_shader_module;
+    BluCat::INT::core.vk_device_with_swapchain->vert3d_shader_module;
   vert_shader_stage_info.pName = "main";
   vert_shader_stage_info.pSpecializationInfo = nullptr;
 
@@ -50,7 +50,7 @@ load_pipeline(void *obj)
   frag_shader_stage_info.flags = 0;
   frag_shader_stage_info.stage = VK_SHADER_STAGE_FRAGMENT_BIT;
   frag_shader_stage_info.module =
-    BluCat::core.vk_device_with_swapchain->frag3d_shader_module;
+    BluCat::INT::core.vk_device_with_swapchain->frag3d_shader_module;
   frag_shader_stage_info.pName = "main";
   frag_shader_stage_info.pSpecializationInfo = nullptr;
 
@@ -61,7 +61,7 @@ load_pipeline(void *obj)
 
   VkVertexInputBindingDescription vertex_input_binding{};
   vertex_input_binding.binding = 0;
-  vertex_input_binding.stride = sizeof(BluCat::StaticMeshVertex);
+  vertex_input_binding.stride = sizeof(BluCat::GRA::StaticMeshVertex);
   vertex_input_binding.inputRate = VK_VERTEX_INPUT_RATE_VERTEX;
 
   std::array<VkVertexInputAttributeDescription, 3> vertex_attribute{};
@@ -69,17 +69,17 @@ load_pipeline(void *obj)
   vertex_attribute[0].location = 0;
   vertex_attribute[0].binding = 0;
   vertex_attribute[0].format = VK_FORMAT_R32G32B32_SFLOAT;
-  vertex_attribute[0].offset = offsetof(BluCat::StaticMeshVertex, position);
+  vertex_attribute[0].offset = offsetof(BluCat::GRA::StaticMeshVertex, position);
   // Normal.
   vertex_attribute[1].location = 1;
   vertex_attribute[1].binding = 0;
   vertex_attribute[1].format = VK_FORMAT_R32G32B32_SFLOAT;
-  vertex_attribute[1].offset = offsetof(BluCat::StaticMeshVertex, normal);
+  vertex_attribute[1].offset = offsetof(BluCat::GRA::StaticMeshVertex, normal);
   // Texture coordinate.
   vertex_attribute[2].location = 2;
   vertex_attribute[2].binding = 0;
   vertex_attribute[2].format = VK_FORMAT_R32G32_SFLOAT;
-  vertex_attribute[2].offset = offsetof(BluCat::StaticMeshVertex, texture_coord);
+  vertex_attribute[2].offset = offsetof(BluCat::GRA::StaticMeshVertex, texture_coord);
 
   VkPipelineVertexInputStateCreateInfo vertex_input_info = {};
   vertex_input_info.sType =
@@ -103,14 +103,14 @@ load_pipeline(void *obj)
   VkViewport viewport = {};
   viewport.x = 0;
   viewport.y = 0;
-  viewport.width = BluCat::core.display_width;
-  viewport.height = BluCat::core.display_height;
+  viewport.width = BluCat::INT::core.display_width;
+  viewport.height = BluCat::INT::core.display_height;
   viewport.minDepth = 0.0f;
   viewport.maxDepth = 1.0f;
 
   VkRect2D scissor = {};
   scissor.offset = {0, 0};
-  scissor.extent = {BluCat::core.display_width, BluCat::core.display_height};
+  scissor.extent = {BluCat::INT::core.display_width, BluCat::INT::core.display_height};
 
   VkPipelineViewportStateCreateInfo viewport_state = {};
   viewport_state.sType =
@@ -213,14 +213,14 @@ load_pipeline(void *obj)
   pipeline_info.pDepthStencilState = &depth_stencil;
   pipeline_info.pColorBlendState = &color_blending;
   pipeline_info.pDynamicState = &dynamic_state_info;
-  pipeline_info.layout = BluCat::core.vk_graphics_pipeline_3d_layout->pipeline;
-  pipeline_info.renderPass = BluCat::core.vk_render_pass->pipeline_3d;
+  pipeline_info.layout = BluCat::INT::core.vk_graphics_pipeline_3d_layout->pipeline;
+  pipeline_info.renderPass = BluCat::INT::core.vk_render_pass->pipeline_3d;
   pipeline_info.subpass = 0;
   pipeline_info.basePipelineHandle = VK_NULL_HANDLE;
   pipeline_info.basePipelineIndex = -1;
 
   if(vkCreateGraphicsPipelines(
-       BluCat::core.vk_device_with_swapchain->device, VK_NULL_HANDLE, 1,
+       BluCat::INT::core.vk_device_with_swapchain->device, VK_NULL_HANDLE, 1,
        &pipeline_info, nullptr, &self->graphic_pipeline)
      != VK_SUCCESS)
     throw CommandError{"Failed to create graphics pipeline."};
@@ -229,10 +229,10 @@ load_pipeline(void *obj)
 void
 unload_pipeline(void *obj)
 {
-  auto self = static_cast<BluCat::GraphicsPipeline3D*>(obj);
+  auto self = static_cast<BluCat::GRA::GraphicsPipeline3D*>(obj);
 
   vkDestroyPipeline(
-    BluCat::core.vk_device_with_swapchain->device, self->graphic_pipeline,
+    BluCat::INT::core.vk_device_with_swapchain->device, self->graphic_pipeline,
 		nullptr);
 }
 
@@ -242,7 +242,7 @@ const CommandChain loader{
 
 }
 
-namespace BluCat
+namespace BluCat::GRA
 {
 
 GraphicsPipeline3D::GraphicsPipeline3D()
@@ -266,7 +266,7 @@ GraphicsPipeline3D::draw(
 
   // Draw models
   for(auto& [static_mesh, instances]:
-	core.vk_renderer->static_models_to_draw[current_frame])
+				INT::core.vk_renderer->static_models_to_draw[current_frame])
   {
       VkBuffer vertex_buffers[]{static_mesh->vertex_buffer->buffer};
       VkDeviceSize offsets[]{0};
@@ -285,20 +285,20 @@ GraphicsPipeline3D::draw(
 	glm::mat4 rotation_matrix{glm::toMat4(*instance->orientation)};
 
 	std::array<VkDescriptorSet, 4> vk_descriptor_sets{
-	  core.vk_light->descriptor_sets_world[image_index],
+	  INT::core.vk_light->descriptor_sets_world[image_index],
 	  view->descriptor_sets_3d[image_index],
 	  instance->descriptor_sets[image_index],
 	  instance->texture->descriptor_sets[image_index]};
 
 	vkCmdBindDescriptorSets(
 	  draw_command_buffer, VK_PIPELINE_BIND_POINT_GRAPHICS,
-	  core.vk_graphics_pipeline_3d_layout->pipeline, 0,
+	  INT::core.vk_graphics_pipeline_3d_layout->pipeline, 0,
 	  vk_descriptor_sets.size(), vk_descriptor_sets.data(), 0, nullptr);
 
         vkCmdDrawIndexed(
           draw_command_buffer, static_mesh->index_count, 1, 0, 0, 0);
 
-	BluCat::UDOStaticModel udo_static_model{};
+	BluCat::GRA::UDOStaticModel udo_static_model{};
 	udo_static_model.base_matrix = translation_matrix * rotation_matrix;
 	instance->uniform_buffers[image_index].copy_data(&udo_static_model);
       }
diff --git a/src/blucat/graphics_pipeline_3d.hpp b/src/blu_cat/gra/graphics_pipeline_3d.hpp
index 6942955..0dc0b03 100644
--- a/src/blucat/graphics_pipeline_3d.hpp
+++ b/src/blu_cat/gra/graphics_pipeline_3d.hpp
@@ -14,8 +14,8 @@
  * limitations under the License.
  */
 
-#ifndef CANDY_GEAR_BLUCAT_GRAPHICS_PIPELINE_3D_H
-#define CANDY_GEAR_BLUCAT_GRAPHICS_PIPELINE_3D_H 1
+#ifndef BLU_CAT_GRA_GRAPHICS_PIPELINE_3D_H
+#define BLU_CAT_GRA_GRAPHICS_PIPELINE_3D_H 1
 
 #include <memory>
 
@@ -23,7 +23,7 @@
 #include "command_pool.hpp"
 #include "view_3d.hpp"
 
-namespace BluCat
+namespace BluCat::GRA
 {
 
 struct GraphicsPipeline3D
@@ -40,4 +40,4 @@ struct GraphicsPipeline3D
 
 }
 
-#endif /* CANDY_GEAR_BLUCAT_GRAPHICS_PIPELINE_3D_H */
+#endif /* BLU_CAT_GRA_GRAPHICS_PIPELINE_3D_H */
diff --git a/src/blucat/graphics_pipeline_3d_layout.cpp b/src/blu_cat/gra/graphics_pipeline_3d_layout.cpp
index 6bac1bb..504b46e 100644
--- a/src/blucat/graphics_pipeline_3d_layout.cpp
+++ b/src/blu_cat/gra/graphics_pipeline_3d_layout.cpp
@@ -18,7 +18,7 @@
 
 #include <array>
 
-#include "core.hpp"
+#include "../int/core.hpp"
 #include "uniform_data_object.hpp"
 
 namespace
@@ -27,13 +27,13 @@ namespace
 void
 load_pipeline(void *obj)
 {
-  auto self = static_cast<BluCat::GraphicsPipeline3DLayout*>(obj);
+  auto self = static_cast<BluCat::GRA::GraphicsPipeline3DLayout*>(obj);
 
   std::array<VkDescriptorSetLayout, 4> set_layouts{
-    BluCat::core.vk_descriptor_set_layout->world,
-    BluCat::core.vk_descriptor_set_layout->view,
-    BluCat::core.vk_descriptor_set_layout->model,
-    BluCat::core.vk_descriptor_set_layout->texture};
+    BluCat::INT::core.vk_descriptor_set_layout->world,
+    BluCat::INT::core.vk_descriptor_set_layout->view,
+    BluCat::INT::core.vk_descriptor_set_layout->model,
+    BluCat::INT::core.vk_descriptor_set_layout->texture};
 
   VkPipelineLayoutCreateInfo pipeline_layout_info{};
   pipeline_layout_info.sType = VK_STRUCTURE_TYPE_PIPELINE_LAYOUT_CREATE_INFO;
@@ -43,7 +43,7 @@ load_pipeline(void *obj)
   pipeline_layout_info.pPushConstantRanges = nullptr;
 
   if(vkCreatePipelineLayout(
-       BluCat::core.vk_device_with_swapchain->device,
+       BluCat::INT::core.vk_device_with_swapchain->device,
        &pipeline_layout_info, nullptr, &self->pipeline) != VK_SUCCESS)
     throw CommandError{"Failed to create Vulkan pipeline layout."};
 }
@@ -51,10 +51,10 @@ load_pipeline(void *obj)
 void
 unload_pipeline(void *obj)
 {
-  auto self = static_cast<BluCat::GraphicsPipeline3DLayout*>(obj);
+  auto self = static_cast<BluCat::GRA::GraphicsPipeline3DLayout*>(obj);
 
   vkDestroyPipelineLayout(
-    BluCat::core.vk_device_with_swapchain->device, self->pipeline, nullptr);
+    BluCat::INT::core.vk_device_with_swapchain->device, self->pipeline, nullptr);
 }
 
 const CommandChain loader{
@@ -63,7 +63,7 @@ const CommandChain loader{
 
 }
 
-namespace BluCat
+namespace BluCat::GRA
 {
 
 GraphicsPipeline3DLayout::GraphicsPipeline3DLayout()
diff --git a/src/blucat/graphics_pipeline_3d_layout.hpp b/src/blu_cat/gra/graphics_pipeline_3d_layout.hpp
index bc86646..13820c4 100644
--- a/src/blucat/graphics_pipeline_3d_layout.hpp
+++ b/src/blu_cat/gra/graphics_pipeline_3d_layout.hpp
@@ -14,12 +14,12 @@
  * limitations under the License.
  */
 
-#ifndef CANDY_GEAR_BLUCAT_GRAPHICS_PIPELINE_3D_LAYOUT_H
-#define CANDY_GEAR_BLUCAT_GRAPHICS_PIPELINE_3D_LAYOUT_H 1
+#ifndef BLU_CAT_GRA_GRAPHICS_PIPELINE_3D_LAYOUT_H
+#define BLU_CAT_GRA_GRAPHICS_PIPELINE_3D_LAYOUT_H 1
 
 #include "vulkan.hpp"
 
-namespace BluCat
+namespace BluCat::GRA
 {
 
 struct GraphicsPipeline3DLayout
@@ -32,4 +32,4 @@ struct GraphicsPipeline3DLayout
 
 }
 
-#endif /* CANDY_GEAR_BLUCAT_GRAPHICS_PIPELINE_3D_LAYOUT_H */
+#endif /* BLU_CAT_GRA_GRAPHICS_PIPELINE_3D_LAYOUT_H */
diff --git a/src/blucat/graphics_pipeline_3d_skeletal.cpp b/src/blu_cat/gra/graphics_pipeline_3d_skeletal.cpp
index 6b56221..e8eda6b 100644
--- a/src/blucat/graphics_pipeline_3d_skeletal.cpp
+++ b/src/blu_cat/gra/graphics_pipeline_3d_skeletal.cpp
@@ -19,7 +19,7 @@
 #include <array>
 #include <stdexcept>
 
-#include "core.hpp"
+#include "../int/core.hpp"
 #include "skeletal_mesh_vertex.hpp"
 #include "uniform_data_object.hpp"
 
@@ -29,7 +29,7 @@ namespace
 void
 load_pipeline(void *obj)
 {
-  auto self = static_cast<BluCat::GraphicsPipeline3DSkeletal*>(obj);
+  auto self = static_cast<BluCat::GRA::GraphicsPipeline3DSkeletal*>(obj);
 
   VkPipelineShaderStageCreateInfo vert_shader_stage_info = {};
   vert_shader_stage_info.sType =
@@ -38,7 +38,7 @@ load_pipeline(void *obj)
   vert_shader_stage_info.flags = 0;
   vert_shader_stage_info.stage = VK_SHADER_STAGE_VERTEX_BIT;
   vert_shader_stage_info.module =
-    BluCat::core.vk_device_with_swapchain->vert3d_skeletal_shader_module;
+    BluCat::INT::core.vk_device_with_swapchain->vert3d_skeletal_shader_module;
   vert_shader_stage_info.pName = "main";
   vert_shader_stage_info.pSpecializationInfo = nullptr;
 
@@ -49,7 +49,7 @@ load_pipeline(void *obj)
   frag_shader_stage_info.flags = 0;
   frag_shader_stage_info.stage = VK_SHADER_STAGE_FRAGMENT_BIT;
   frag_shader_stage_info.module =
-    BluCat::core.vk_device_with_swapchain->frag3d_shader_module;
+    BluCat::INT::core.vk_device_with_swapchain->frag3d_shader_module;
   frag_shader_stage_info.pName = "main";
   frag_shader_stage_info.pSpecializationInfo = nullptr;
 
@@ -60,7 +60,7 @@ load_pipeline(void *obj)
 
   VkVertexInputBindingDescription vertex_input_binding{};
   vertex_input_binding.binding = 0;
-  vertex_input_binding.stride = sizeof(BluCat::SkeletalMeshVertex);
+  vertex_input_binding.stride = sizeof(BluCat::GRA::SkeletalMeshVertex);
   vertex_input_binding.inputRate = VK_VERTEX_INPUT_RATE_VERTEX;
 
   std::array<VkVertexInputAttributeDescription, 5> vertex_attribute{};
@@ -68,27 +68,27 @@ load_pipeline(void *obj)
   vertex_attribute[0].location = 0;
   vertex_attribute[0].binding = 0;
   vertex_attribute[0].format = VK_FORMAT_R32G32B32_SFLOAT;
-  vertex_attribute[0].offset = offsetof(BluCat::SkeletalMeshVertex, position);
+  vertex_attribute[0].offset = offsetof(BluCat::GRA::SkeletalMeshVertex, position);
   // Normal.
   vertex_attribute[1].location = 1;
   vertex_attribute[1].binding = 0;
   vertex_attribute[1].format = VK_FORMAT_R32G32B32_SFLOAT;
-  vertex_attribute[1].offset = offsetof(BluCat::SkeletalMeshVertex, normal);
+  vertex_attribute[1].offset = offsetof(BluCat::GRA::SkeletalMeshVertex, normal);
   // Texture coordinate.
   vertex_attribute[2].location = 2;
   vertex_attribute[2].binding = 0;
   vertex_attribute[2].format = VK_FORMAT_R32G32_SFLOAT;
-  vertex_attribute[2].offset = offsetof(BluCat::SkeletalMeshVertex, texture_coord);
+  vertex_attribute[2].offset = offsetof(BluCat::GRA::SkeletalMeshVertex, texture_coord);
   // Bones ids.
   vertex_attribute[3].location = 3;
   vertex_attribute[3].binding = 0;
   vertex_attribute[3].format = VK_FORMAT_R32G32B32A32_SINT;
-  vertex_attribute[3].offset = offsetof(BluCat::SkeletalMeshVertex, bone_ids);
+  vertex_attribute[3].offset = offsetof(BluCat::GRA::SkeletalMeshVertex, bone_ids);
   // Bones weights.
   vertex_attribute[4].location = 4;
   vertex_attribute[4].binding = 0;
   vertex_attribute[4].format = VK_FORMAT_R32G32B32A32_SFLOAT;
-  vertex_attribute[4].offset = offsetof(BluCat::SkeletalMeshVertex, bone_weights);
+  vertex_attribute[4].offset = offsetof(BluCat::GRA::SkeletalMeshVertex, bone_weights);
 
   VkPipelineVertexInputStateCreateInfo vertex_input_info = {};
   vertex_input_info.sType =
@@ -112,14 +112,14 @@ load_pipeline(void *obj)
   VkViewport viewport = {};
   viewport.x = 0;
   viewport.y = 0;
-  viewport.width = BluCat::core.display_width;
-  viewport.height = BluCat::core.display_height;
+  viewport.width = BluCat::INT::core.display_width;
+  viewport.height = BluCat::INT::core.display_height;
   viewport.minDepth = 0.0f;
   viewport.maxDepth = 1.0f;
 
   VkRect2D scissor = {};
   scissor.offset = {0, 0};
-  scissor.extent = {BluCat::core.display_width, BluCat::core.display_height};
+  scissor.extent = {BluCat::INT::core.display_width, BluCat::INT::core.display_height};
 
   VkPipelineViewportStateCreateInfo viewport_state = {};
   viewport_state.sType =
@@ -222,14 +222,14 @@ load_pipeline(void *obj)
   pipeline_info.pDepthStencilState = &depth_stencil;
   pipeline_info.pColorBlendState = &color_blending;
   pipeline_info.pDynamicState = &dynamic_state_info;
-  pipeline_info.layout = BluCat::core.vk_graphics_pipeline_3d_layout->pipeline;
-  pipeline_info.renderPass = BluCat::core.vk_render_pass->pipeline_3d;
+  pipeline_info.layout = BluCat::INT::core.vk_graphics_pipeline_3d_layout->pipeline;
+  pipeline_info.renderPass = BluCat::INT::core.vk_render_pass->pipeline_3d;
   pipeline_info.subpass = 0;
   pipeline_info.basePipelineHandle = VK_NULL_HANDLE;
   pipeline_info.basePipelineIndex = -1;
 
   if(vkCreateGraphicsPipelines(
-       BluCat::core.vk_device_with_swapchain->device, VK_NULL_HANDLE, 1,
+       BluCat::INT::core.vk_device_with_swapchain->device, VK_NULL_HANDLE, 1,
        &pipeline_info, nullptr, &self->graphic_pipeline)
      != VK_SUCCESS)
     throw CommandError{"Failed to create graphics pipeline."};
@@ -238,10 +238,10 @@ load_pipeline(void *obj)
 void
 unload_pipeline(void *obj)
 {
-  auto self = static_cast<BluCat::GraphicsPipeline3DSkeletal*>(obj);
+  auto self = static_cast<BluCat::GRA::GraphicsPipeline3DSkeletal*>(obj);
 
   vkDestroyPipeline(
-    BluCat::core.vk_device_with_swapchain->device, self->graphic_pipeline,
+    BluCat::INT::core.vk_device_with_swapchain->device, self->graphic_pipeline,
 		nullptr);
 }
 
@@ -251,7 +251,7 @@ const CommandChain loader{
 
 }
 
-namespace BluCat
+namespace BluCat::GRA
 {
 
 GraphicsPipeline3DSkeletal::GraphicsPipeline3DSkeletal()
@@ -275,7 +275,7 @@ GraphicsPipeline3DSkeletal::draw(
 
 	// Draw models
 	for(auto& [skeletal_mesh, instances]:
-	core.vk_renderer->skeletal_models_to_draw[current_frame])
+				INT::core.vk_renderer->skeletal_models_to_draw[current_frame])
 	{
 		VkBuffer vertex_buffers[]{skeletal_mesh->vertex_buffer->buffer};
 		VkDeviceSize offsets[]{0};
@@ -294,21 +294,21 @@ GraphicsPipeline3DSkeletal::draw(
 			glm::mat4 rotation_matrix{glm::toMat4(*instance->orientation)};
 
 			std::array<VkDescriptorSet, 4> vk_descriptor_sets{
-				core.vk_light->descriptor_sets_world[image_index],
+				INT::core.vk_light->descriptor_sets_world[image_index],
 				view->descriptor_sets_3d[image_index],
 				instance->descriptor_sets[image_index],
 				instance->texture->descriptor_sets[image_index]};
 
 			vkCmdBindDescriptorSets(
 				draw_command_buffer, VK_PIPELINE_BIND_POINT_GRAPHICS,
-				core.vk_graphics_pipeline_3d_layout->pipeline, 0,
+				INT::core.vk_graphics_pipeline_3d_layout->pipeline, 0,
 				vk_descriptor_sets.size(), vk_descriptor_sets.data(), 0, nullptr);
 
 			vkCmdDrawIndexed(
 				draw_command_buffer, skeletal_mesh->index_count, 1, 0, 0, 0);
 
-			BluCat::UDOSkeletalModel udo_skeletal_model{};
-			instance->tick(core.delta_time);
+			BluCat::GRA::UDOSkeletalModel udo_skeletal_model{};
+			instance->tick(INT::core.delta_time);
 			udo_skeletal_model.base_matrix = translation_matrix * rotation_matrix;
 			std::copy(instance->bone_transforms.begin(),
 								instance->bone_transforms.end(),
diff --git a/src/blucat/graphics_pipeline_3d_skeletal.hpp b/src/blu_cat/gra/graphics_pipeline_3d_skeletal.hpp
index 52810f6..bad117d 100644
--- a/src/blucat/graphics_pipeline_3d_skeletal.hpp
+++ b/src/blu_cat/gra/graphics_pipeline_3d_skeletal.hpp
@@ -14,8 +14,8 @@
  * limitations under the License.
  */
 
-#ifndef CANDY_GEAR_BLUCAT_GRAPHICS_PIPELINE_3D_SKELETAL_H
-#define CANDY_GEAR_BLUCAT_GRAPHICS_PIPELINE_3D_SKELETAL_H 1
+#ifndef BLU_CAT_GRA_GRAPHICS_PIPELINE_3D_SKELETAL_H
+#define BLU_CAT_GRA_GRAPHICS_PIPELINE_3D_SKELETAL_H 1
 
 #include <memory>
 
@@ -23,7 +23,7 @@
 #include "command_pool.hpp"
 #include "view_3d.hpp"
 
-namespace BluCat
+namespace BluCat::GRA
 {
 
 struct GraphicsPipeline3DSkeletal
@@ -40,4 +40,4 @@ struct GraphicsPipeline3DSkeletal
 
 }
 
-#endif /* CANDY_GEAR_BLUCAT_GRAPHICS_PIPELINE_SKELETAL_3D_H */
+#endif /* BLU_CAT_GRA_GRAPHICS_PIPELINE_SKELETAL_3D_H */
diff --git a/src/blucat/graphics_pipeline_sprite_3d.cpp b/src/blu_cat/gra/graphics_pipeline_sprite_3d.cpp
index f87b7e1..14796d3 100644
--- a/src/blucat/graphics_pipeline_sprite_3d.cpp
+++ b/src/blu_cat/gra/graphics_pipeline_sprite_3d.cpp
@@ -18,7 +18,7 @@
 
 #include <array>
 
-#include "core.hpp"
+#include "../int/core.hpp"
 #include "sprite.hpp"
 #include "uniform_data_object.hpp"
 
@@ -27,7 +27,7 @@ namespace
 
 struct Sprite3DOrder
 {
-  std::shared_ptr<BluCat::Sprite3D> sprite_3d;
+  std::shared_ptr<BluCat::GRA::Sprite3D> sprite_3d;
   float distance;
 };
 
@@ -46,7 +46,7 @@ operator>(const Sprite3DOrder &a, const Sprite3DOrder &b)
 void
 load_pipeline(void *obj)
 {
-  auto self = static_cast<BluCat::GraphicsPipelineSprite3D*>(obj);
+  auto self = static_cast<BluCat::GRA::GraphicsPipelineSprite3D*>(obj);
 
   VkPipelineShaderStageCreateInfo vert_shader_stage_info{};
   vert_shader_stage_info.sType =
@@ -55,7 +55,7 @@ load_pipeline(void *obj)
   vert_shader_stage_info.flags = 0;
   vert_shader_stage_info.stage = VK_SHADER_STAGE_VERTEX_BIT;
   vert_shader_stage_info.module =
-    BluCat::core.vk_device_with_swapchain->vert_sprite_3d_shader_module;
+    BluCat::INT::core.vk_device_with_swapchain->vert_sprite_3d_shader_module;
   vert_shader_stage_info.pName = "main";
   vert_shader_stage_info.pSpecializationInfo = nullptr;
 
@@ -66,7 +66,7 @@ load_pipeline(void *obj)
   frag_shader_stage_info.flags = 0;
   frag_shader_stage_info.stage = VK_SHADER_STAGE_FRAGMENT_BIT;
   frag_shader_stage_info.module =
-    BluCat::core.vk_device_with_swapchain->frag_sprite_3d_shader_module;
+    BluCat::INT::core.vk_device_with_swapchain->frag_sprite_3d_shader_module;
   frag_shader_stage_info.pName = "main";
   frag_shader_stage_info.pSpecializationInfo = nullptr;
 
@@ -109,14 +109,14 @@ load_pipeline(void *obj)
   VkViewport viewport = {};
   viewport.x = 0;
   viewport.y = 0;
-  viewport.width = BluCat::core.display_width;
-  viewport.height = BluCat::core.display_height;
+  viewport.width = BluCat::INT::core.display_width;
+  viewport.height = BluCat::INT::core.display_height;
   viewport.minDepth = 0.0f;
   viewport.maxDepth = 1.0f;
 
   VkRect2D scissor = {};
   scissor.offset = {0, 0};
-  scissor.extent = {BluCat::core.display_width, BluCat::core.display_height};
+  scissor.extent = {BluCat::INT::core.display_width, BluCat::INT::core.display_height};
 
   VkPipelineViewportStateCreateInfo viewport_state = {};
   viewport_state.sType =
@@ -221,14 +221,14 @@ load_pipeline(void *obj)
   pipeline_info.pDepthStencilState = &depth_stencil;
   pipeline_info.pColorBlendState = &color_blending;
   pipeline_info.pDynamicState = &dynamic_state_info;
-  pipeline_info.layout = BluCat::core.vk_graphics_pipeline_3d_layout->pipeline;
-  pipeline_info.renderPass = BluCat::core.vk_render_pass->pipeline_3d;
+  pipeline_info.layout = BluCat::INT::core.vk_graphics_pipeline_3d_layout->pipeline;
+  pipeline_info.renderPass = BluCat::INT::core.vk_render_pass->pipeline_3d;
   pipeline_info.subpass = 0;
   pipeline_info.basePipelineHandle = VK_NULL_HANDLE;
   pipeline_info.basePipelineIndex = -1;
 
   if(vkCreateGraphicsPipelines(
-       BluCat::core.vk_device_with_swapchain->device, VK_NULL_HANDLE, 1,
+       BluCat::INT::core.vk_device_with_swapchain->device, VK_NULL_HANDLE, 1,
        &pipeline_info, nullptr, &self->graphic_pipeline)
      != VK_SUCCESS)
     throw CommandError{"Failed to create graphics pipeline sprite 3d."};
@@ -237,10 +237,10 @@ load_pipeline(void *obj)
 void
 unload_pipeline(void *obj)
 {
-  auto self = static_cast<BluCat::GraphicsPipelineSprite3D*>(obj);
+  auto self = static_cast<BluCat::GRA::GraphicsPipelineSprite3D*>(obj);
 
   vkDestroyPipeline(
-    BluCat::core.vk_device_with_swapchain->device, self->graphic_pipeline,
+    BluCat::INT::core.vk_device_with_swapchain->device, self->graphic_pipeline,
 		nullptr);
 }
 
@@ -250,7 +250,7 @@ const CommandChain loader{
 
 }
 
-namespace BluCat
+namespace BluCat::GRA
 {
 
 GraphicsPipelineSprite3D::GraphicsPipelineSprite3D()
@@ -275,10 +275,10 @@ GraphicsPipelineSprite3D::draw(
   std::vector<Sprite3DOrder> sprite_3d_order;
   { // Sort sprites 3D
     sprite_3d_order.reserve(
-      core.vk_renderer->sprites_3d_to_draw[current_frame].size());
+      INT::core.vk_renderer->sprites_3d_to_draw[current_frame].size());
 
-    for(std::shared_ptr<BluCat::Sprite3D> sprite:
-	  core.vk_renderer->sprites_3d_to_draw[current_frame])
+    for(std::shared_ptr<BluCat::GRA::Sprite3D> sprite:
+	  INT::core.vk_renderer->sprites_3d_to_draw[current_frame])
       sprite_3d_order.emplace_back(
 	sprite, glm::distance(*view->camera_position, *sprite->position));
 
@@ -289,7 +289,7 @@ GraphicsPipelineSprite3D::draw(
   for(auto& sprite: sprite_3d_order)
   {
     std::array<VkDescriptorSet, 4> vk_descriptor_sets{
-      core.vk_light->descriptor_sets_world[image_index],
+			INT::core.vk_light->descriptor_sets_world[image_index],
       view->descriptor_sets_3d[image_index],
       sprite.sprite_3d->descriptor_sets[image_index],
       sprite.sprite_3d->sprite->texture->descriptor_sets[image_index]};
@@ -300,7 +300,7 @@ GraphicsPipelineSprite3D::draw(
       &sprite.sprite_3d->sprite->vertex_buffer->buffer, offsets);
     vkCmdBindDescriptorSets(
       draw_command_buffer, VK_PIPELINE_BIND_POINT_GRAPHICS,
-      core.vk_graphics_pipeline_3d_layout->pipeline, 0,
+      INT::core.vk_graphics_pipeline_3d_layout->pipeline, 0,
       vk_descriptor_sets.size(), vk_descriptor_sets.data(), 0, nullptr);
 
     UDOSprite3D ubo_sprite_3d{};
diff --git a/src/blucat/graphics_pipeline_sprite_3d.hpp b/src/blu_cat/gra/graphics_pipeline_sprite_3d.hpp
index 237094d..325d943 100644
--- a/src/blucat/graphics_pipeline_sprite_3d.hpp
+++ b/src/blu_cat/gra/graphics_pipeline_sprite_3d.hpp
@@ -14,8 +14,8 @@
  * limitations under the License.
  */
 
-#ifndef CANDY_GEAR_BLUCAT_GRAPHICS_PIPELINE_SPRITE_3D_H
-#define CANDY_GEAR_BLUCAT_GRAPHICS_PIPELINE_SPRITE_3D_H 1
+#ifndef BLU_CAT_GRA_GRAPHICS_PIPELINE_SPRITE_3D_H
+#define BLU_CAT_GRA_GRAPHICS_PIPELINE_SPRITE_3D_H 1
 
 #include <memory>
 
@@ -24,7 +24,7 @@
 #include "sprite_3d.hpp"
 #include "view_3d.hpp"
 
-namespace BluCat
+namespace BluCat::GRA
 {
 
 struct GraphicsPipelineSprite3D
@@ -41,4 +41,4 @@ struct GraphicsPipelineSprite3D
 
 }
 
-#endif /* CANDY_GEAR_BLUCAT_GRAPHICS_PIPELINE_SPRITE_3D_H */
+#endif /* BLU_CAT_GRA_GRAPHICS_PIPELINE_SPRITE_3D_H */
diff --git a/src/blucat/image.cpp b/src/blu_cat/gra/image.cpp
index 81b1563..76e4f9d 100644
--- a/src/blucat/image.cpp
+++ b/src/blu_cat/gra/image.cpp
@@ -16,9 +16,9 @@
 
 #include "image.hpp"
 
-#include "core.hpp"
+#include "../int/core.hpp"
 
-namespace BluCat::Image
+namespace BluCat::GRA::Image
 {
 
 Error::Error(const std::string &m):
@@ -39,7 +39,7 @@ Error::what() const noexcept
 
 void
 create(
-  BluCat::Device *device,
+  BluCat::GRA::Device *device,
   VkImage *image,
   VkDeviceMemory *image_memory,
   VkFormat format,
@@ -117,7 +117,7 @@ void move_image_state(
 }
 
 void create_view(
-  BluCat::Device *device,
+  BluCat::GRA::Device *device,
   VkImageView *image_view,
   const VkImage &image,
   VkFormat format,
diff --git a/src/blucat/image.hpp b/src/blu_cat/gra/image.hpp
index 67c1933..ba64b76 100644
--- a/src/blucat/image.hpp
+++ b/src/blu_cat/gra/image.hpp
@@ -14,8 +14,8 @@
  * limitations under the License.
  */
 
-#ifndef BLUE_KITTY_BLUCAT_IMAGE_H
-#define BLUE_KITTY_BLUCAT_IMAGE_H 1
+#ifndef BLU_CAT_GRA_IMAGE_H
+#define BLU_CAT_GRA_IMAGE_H 1
 
 #include <memory>
 #include <string>
@@ -23,7 +23,7 @@
 #include "vulkan.hpp"
 #include "device.hpp"
 
-namespace BluCat::Image
+namespace BluCat::GRA::Image
 {
 
 struct Error: public std::exception
@@ -40,7 +40,7 @@ private:
 
 void
 create(
-  BluCat::Device *device,
+  BluCat::GRA::Device *device,
   VkImage *image,
   VkDeviceMemory *image_memory,
   VkFormat format,
@@ -63,11 +63,11 @@ move_image_state(
 
 void
 create_view(
-  BluCat::Device *device,
+  BluCat::GRA::Device *device,
   VkImageView *image_view,
   const VkImage &image,
   VkFormat format,
   VkImageAspectFlags image_aspect_flags);
 }
 
-#endif /* CANDY_GEAR_BLUCAT_IMAGE_H */
+#endif /* BLU_CAT_GRA_IMAGE_H */
diff --git a/src/blucat/light.cpp b/src/blu_cat/gra/light.cpp
index 43611a1..403dcf4 100644
--- a/src/blucat/light.cpp
+++ b/src/blu_cat/gra/light.cpp
@@ -18,7 +18,7 @@
 
 #include <array>
 
-#include "core.hpp"
+#include "../int/core.hpp"
 #include "uniform_data_object.hpp"
 
 namespace
@@ -27,14 +27,14 @@ namespace
 void
 load_world_vert_uniform_buffer(void *obj)
 {
-  auto self = static_cast<BluCat::Light*>(obj);
+  auto self = static_cast<BluCat::GRA::Light*>(obj);
 
   try
   {
-    self->ub_world_vert.reserve(BluCat::core.vk_swapchain->images_count);
-    for(auto i{0}; i < BluCat::core.vk_swapchain->images_count; i++)
+    self->ub_world_vert.reserve(BluCat::INT::core.vk_swapchain->images_count);
+    for(auto i{0}; i < BluCat::INT::core.vk_swapchain->images_count; i++)
       self->ub_world_vert.emplace_back(
-	BluCat::core.vk_device_with_swapchain, sizeof(BluCat::UDOWorld3D_Vert));
+	BluCat::INT::core.vk_device_with_swapchain, sizeof(BluCat::GRA::UDOWorld3D_Vert));
   }
   catch(const std::exception& e)
   {
@@ -45,7 +45,7 @@ load_world_vert_uniform_buffer(void *obj)
 void
 unload_world_vert_uniform_buffer(void *obj)
 {
-  auto self = static_cast<BluCat::Light*>(obj);
+  auto self = static_cast<BluCat::GRA::Light*>(obj);
 
   self->ub_world_vert.clear();
 }
@@ -53,14 +53,14 @@ unload_world_vert_uniform_buffer(void *obj)
 void
 load_world_frag_uniform_buffer(void *obj)
 {
-  auto self = static_cast<BluCat::Light*>(obj);
+  auto self = static_cast<BluCat::GRA::Light*>(obj);
 
   try
   {
-    self->ub_world_frag.reserve(BluCat::core.vk_swapchain->images_count);
-    for(auto i{0}; i < BluCat::core.vk_swapchain->images_count; i++)
+    self->ub_world_frag.reserve(BluCat::INT::core.vk_swapchain->images_count);
+    for(auto i{0}; i < BluCat::INT::core.vk_swapchain->images_count; i++)
       self->ub_world_frag.emplace_back(
-	BluCat::core.vk_device_with_swapchain, sizeof(BluCat::UDOWorld3D_Frag));
+	BluCat::INT::core.vk_device_with_swapchain, sizeof(BluCat::GRA::UDOWorld3D_Frag));
   }
   catch(const std::exception& e)
   {
@@ -71,7 +71,7 @@ load_world_frag_uniform_buffer(void *obj)
 void
 unload_world_frag_uniform_buffer(void *obj)
 {
-  auto self = static_cast<BluCat::Light*>(obj);
+  auto self = static_cast<BluCat::GRA::Light*>(obj);
 
   self->ub_world_frag.clear();
 }
@@ -79,7 +79,7 @@ unload_world_frag_uniform_buffer(void *obj)
 void
 load_descriptor_pool(void *obj)
 {
-  auto self = static_cast<BluCat::Light*>(obj);
+  auto self = static_cast<BluCat::GRA::Light*>(obj);
 
   uint32_t uniform_buffers_count =
     self->ub_world_vert.size() + self->ub_world_vert.size();
@@ -97,7 +97,7 @@ load_descriptor_pool(void *obj)
   pool_info.pPoolSizes = &descriptor_pool_size;
 
   if(vkCreateDescriptorPool(
-       BluCat::core.vk_device_with_swapchain->device, &pool_info, nullptr,
+       BluCat::INT::core.vk_device_with_swapchain->device, &pool_info, nullptr,
        &self->descriptor_pool) != VK_SUCCESS)
     throw CommandError{"Failed to create a Vulkan descriptor pool."};
 }
@@ -105,21 +105,21 @@ load_descriptor_pool(void *obj)
 void
 unload_descriptor_pool(void *obj)
 {
-  auto self = static_cast<BluCat::Light*>(obj);
+  auto self = static_cast<BluCat::GRA::Light*>(obj);
 
   vkDestroyDescriptorPool(
-    BluCat::core.vk_device_with_swapchain->device, self->descriptor_pool,
+    BluCat::INT::core.vk_device_with_swapchain->device, self->descriptor_pool,
     nullptr);
 }
 
 void
 load_descriptor_sets_world(void *obj)
 {
-  auto self = static_cast<BluCat::Light*>(obj);
+  auto self = static_cast<BluCat::GRA::Light*>(obj);
 
   std::vector<VkDescriptorSetLayout> layouts(
-    BluCat::core.vk_swapchain->images_count,
-    BluCat::core.vk_descriptor_set_layout->world);
+    BluCat::INT::core.vk_swapchain->images_count,
+    BluCat::INT::core.vk_descriptor_set_layout->world);
 
   VkDescriptorSetAllocateInfo alloc_info{};
   alloc_info.sType = VK_STRUCTURE_TYPE_DESCRIPTOR_SET_ALLOCATE_INFO;
@@ -129,7 +129,7 @@ load_descriptor_sets_world(void *obj)
 
   self->descriptor_sets_world.resize(layouts.size());
   if(vkAllocateDescriptorSets(
-       BluCat::core.vk_device_with_swapchain->device, &alloc_info,
+       BluCat::INT::core.vk_device_with_swapchain->device, &alloc_info,
        self->descriptor_sets_world.data()) != VK_SUCCESS)
     throw CommandError{"Failed to create Vulkan world descriptor set."};
 }
@@ -137,19 +137,19 @@ load_descriptor_sets_world(void *obj)
 void
 load_resources_to_descriptor_sets(void *obj)
 {
-  auto self = static_cast<BluCat::Light*>(obj);
+  auto self = static_cast<BluCat::GRA::Light*>(obj);
 
-  for(auto i{0}; i < BluCat::core.vk_swapchain->images_count; i++)
+  for(auto i{0}; i < BluCat::INT::core.vk_swapchain->images_count; i++)
   {
     VkDescriptorBufferInfo world_vert_info{};
     world_vert_info.buffer = self->ub_world_vert[i].buffer;
     world_vert_info.offset = 0;
-    world_vert_info.range = sizeof(BluCat::UDOWorld3D_Vert);
+    world_vert_info.range = sizeof(BluCat::GRA::UDOWorld3D_Vert);
 
     VkDescriptorBufferInfo world_frag_info{};
     world_frag_info.buffer = self->ub_world_frag[i].buffer;
     world_frag_info.offset = 0;
-    world_frag_info.range = sizeof(BluCat::UDOWorld3D_Frag);
+    world_frag_info.range = sizeof(BluCat::GRA::UDOWorld3D_Frag);
 
     std::array<VkWriteDescriptorSet, 2> write_descriptors{};
     write_descriptors[0].sType = VK_STRUCTURE_TYPE_WRITE_DESCRIPTOR_SET;
@@ -173,7 +173,7 @@ load_resources_to_descriptor_sets(void *obj)
     write_descriptors[1].pTexelBufferView = nullptr;
 
     vkUpdateDescriptorSets(
-      BluCat::core.vk_device_with_swapchain->device, write_descriptors.size(),
+      BluCat::INT::core.vk_device_with_swapchain->device, write_descriptors.size(),
       write_descriptors.data(), 0, nullptr);
   }
 }
@@ -189,7 +189,7 @@ const CommandChain loader{
 
 }
 
-namespace BluCat
+namespace BluCat::GRA
 {
 
 Light::Light()
diff --git a/src/blucat/light.hpp b/src/blu_cat/gra/light.hpp
index f5f153e..22a9e2d 100644
--- a/src/blucat/light.hpp
+++ b/src/blu_cat/gra/light.hpp
@@ -14,13 +14,13 @@
  * limitations under the License.
  */
 
-#ifndef CANDY_GEAR_BLUCAT_LIGHT_H
-#define CANDY_GEAR_BLUCAT_LIGHT_H 1
+#ifndef BLU_CAT_GRA_LIGHT_H
+#define BLU_CAT_GRA_LIGHT_H 1
 
 #include "vulkan.hpp"
 #include "uniform_buffer.hpp"
 
-namespace BluCat
+namespace BluCat::GRA
 {
 
 struct Light
@@ -38,4 +38,4 @@ struct Light
 
 }
 
-#endif /* CANDY_GEAR_BLUCAT_LIGHT_H */
+#endif /* BLU_CAT_GRA_LIGHT_H */
diff --git a/src/blucat/log.cpp b/src/blu_cat/gra/log.cpp
index 78044c4..78044c4 100644
--- a/src/blucat/log.cpp
+++ b/src/blu_cat/gra/log.cpp
diff --git a/src/blucat/log.hpp b/src/blu_cat/gra/log.hpp
index 2856f20..2856f20 100644
--- a/src/blucat/log.hpp
+++ b/src/blu_cat/gra/log.hpp
diff --git a/src/blucat/qoi.cpp b/src/blu_cat/gra/qoi.cpp
index 3169ecc..790516d 100644
--- a/src/blucat/qoi.cpp
+++ b/src/blu_cat/gra/qoi.cpp
@@ -92,7 +92,7 @@ color_hash(const RGBA &colors)
 
 }
 
-namespace BluCat::QOI
+namespace BluCat::GRA::QOI
 {
 
 Image::Image(const char *file_path, uint8_t channels):
diff --git a/src/blucat/qoi.hpp b/src/blu_cat/gra/qoi.hpp
index cd33205..f8be4ec 100644
--- a/src/blucat/qoi.hpp
+++ b/src/blu_cat/gra/qoi.hpp
@@ -16,7 +16,7 @@
 
 #include <cstdint>
 
-namespace BluCat::QOI
+namespace BluCat::GRA::QOI
 {
   struct Header
   {
diff --git a/src/blucat/queue.cpp b/src/blu_cat/gra/queue.cpp
index c00d874..3f47a19 100644
--- a/src/blucat/queue.cpp
+++ b/src/blu_cat/gra/queue.cpp
@@ -18,11 +18,11 @@
 
 #include "queue_family.hpp"
 
-namespace BluCat
+namespace BluCat::GRA
 {
 
 Queue::Queue(
-  BluCat::QueueFamily *queue_family, VkQueue queue, int queue_index):
+  BluCat::GRA::QueueFamily *queue_family, VkQueue queue, int queue_index):
   queue_family{queue_family},
   queue{queue},
   queue_index{queue_index}
diff --git a/src/blucat/queue.hpp b/src/blu_cat/gra/queue.hpp
index 3be1a94..3dc9833 100644
--- a/src/blucat/queue.hpp
+++ b/src/blu_cat/gra/queue.hpp
@@ -14,18 +14,18 @@
  * limitations under the License.
  */
 
-#ifndef CANDY_GEAR_BLUCAT_QUEUE_H
-#define CANDY_GEAR_BLUCAT_QUEUE_H 1
+#ifndef BLU_CAT_GRA_QUEUE_H
+#define BLU_CAT_GRA_QUEUE_H 1
 
 #include "vulkan.hpp"
 
-namespace BluCat
+namespace BluCat::GRA
 {
 class QueueFamily;
 
 struct Queue
 {
-  friend class BluCat::QueueFamily;
+  friend class BluCat::GRA::QueueFamily;
 
   Queue(const Queue &t) = delete;
   Queue& operator=(const Queue &t) = delete;
@@ -42,10 +42,10 @@ struct Queue
   ~Queue();
 
 private:
-  BluCat::QueueFamily *queue_family;
+  BluCat::GRA::QueueFamily *queue_family;
   int queue_index;
 
-  Queue(BluCat::QueueFamily *queue_family, VkQueue queue, int queue_index);
+  Queue(BluCat::GRA::QueueFamily *queue_family, VkQueue queue, int queue_index);
 };
 
 template<typename T> void
@@ -79,4 +79,4 @@ Queue::submit_one_time_command(
 
 }
 
-#endif /* CANDY_GEAR_BLUCAT_QUEUE_H */
+#endif /* BLU_CAT_GRA_QUEUE_H */
diff --git a/src/blucat/queue_family.cpp b/src/blu_cat/gra/queue_family.cpp
index da799c0..59086b5 100644
--- a/src/blucat/queue_family.cpp
+++ b/src/blu_cat/gra/queue_family.cpp
@@ -20,13 +20,13 @@
 #include <sstream>
 #endif
 
-#include "core.hpp"
+#include "../int/core.hpp"
 
-namespace BluCat
+namespace BluCat::GRA
 {
 
 QueueFamily::QueueFamily(
-  BluCat::Device *device, uint32_t family_index,
+  BluCat::GRA::Device *device, uint32_t family_index,
   const VkQueueFamilyProperties &queue_family_properties):
   queue_mutex{}
 {
@@ -47,7 +47,7 @@ QueueFamily::QueueFamily(
   message << "Sparse Binding: " <<
     (queue_family_properties.queueFlags & VK_QUEUE_SPARSE_BINDING_BIT ?
      "true" : "false") << std::endl;
-  core.log.message(Log::Level::Trace, message.str());
+  INT::core.log.message(Log::Level::Trace, message.str());
 #endif
 
   this->device = device;
diff --git a/src/blucat/queue_family.hpp b/src/blu_cat/gra/queue_family.hpp
index 988748f..4673058 100644
--- a/src/blucat/queue_family.hpp
+++ b/src/blu_cat/gra/queue_family.hpp
@@ -14,8 +14,8 @@
  * limitations under the License.
  */
 
-#ifndef CANDY_GEAR_BLUCAT_QUEUE_FAMILY_H
-#define CANDY_GEAR_BLUCAT_QUEUE_FAMILY_H 1
+#ifndef BLU_CAT_GRA_QUEUE_FAMILY_H
+#define BLU_CAT_GRA_QUEUE_FAMILY_H 1
 
 #include <mutex>
 #include <vector>
@@ -23,7 +23,7 @@
 #include "vulkan.hpp"
 #include "queue.hpp"
 
-namespace BluCat
+namespace BluCat::GRA
 {
 class Device;
 
@@ -41,12 +41,12 @@ class QueueFamily
   std::vector<QueueState> queue_states;
 
 public:
-  BluCat::Device *device;
+  BluCat::GRA::Device *device;
 
   uint32_t family_index;
   VkQueueFamilyProperties family_properties;
 
-  QueueFamily(BluCat::Device *device, uint32_t family_index,
+  QueueFamily(BluCat::GRA::Device *device, uint32_t family_index,
 	      const VkQueueFamilyProperties &queue_family_properties);
 
   Queue
@@ -55,4 +55,4 @@ public:
 
 }
 
-#endif /* CANDY_GEAR_BLUCAT_QUEUE_FAMILY_H */
+#endif /* BLU_CAT_GRA_QUEUE_FAMILY_H */
diff --git a/src/blucat/rectangle.cpp b/src/blu_cat/gra/rectangle.cpp
index 34f844d..ea01a04 100644
--- a/src/blucat/rectangle.cpp
+++ b/src/blu_cat/gra/rectangle.cpp
@@ -16,7 +16,7 @@
 
 #include "rectangle.hpp"
 
-namespace BluCat
+namespace BluCat::GRA
 {
 
 const int Rectangle::VertexCount{4};
diff --git a/src/blucat/rectangle.hpp b/src/blu_cat/gra/rectangle.hpp
index 57c9d4f..cd09239 100644
--- a/src/blucat/rectangle.hpp
+++ b/src/blu_cat/gra/rectangle.hpp
@@ -14,8 +14,8 @@
  * limitations under the License.
  */
 
-#ifndef CANDY_GEAR_BLUCAT_RECTANGLE_H
-#define CANDY_GEAR_BLUCAT_RECTANGLE_H 1
+#ifndef BLU_CAT_GRA_RECTANGLE_H
+#define BLU_CAT_GRA_RECTANGLE_H 1
 
 #include <vector>
 
@@ -24,7 +24,7 @@
 #include "queue_family.hpp"
 #include "uniform_buffer.hpp"
 
-namespace BluCat
+namespace BluCat::GRA
 {
 
 struct Rectangle
@@ -39,4 +39,4 @@ struct Rectangle
 
 }
 
-#endif /* CANDY_GEAR_BLUCAT_RECTANGLE_H */
+#endif /* BLU_CAT_GRA_RECTANGLE_H */
diff --git a/src/blucat/render_pass.cpp b/src/blu_cat/gra/render_pass.cpp
index 2effe6b..64fdf56 100644
--- a/src/blucat/render_pass.cpp
+++ b/src/blu_cat/gra/render_pass.cpp
@@ -18,7 +18,7 @@
 
 #include <array>
 
-#include "core.hpp"
+#include "../int/core.hpp"
 
 namespace
 {
@@ -26,12 +26,12 @@ namespace
 void
 load_3d(void *obj)
 {
-  auto self = static_cast<BluCat::RenderPass*>(obj);
+  auto self = static_cast<BluCat::GRA::RenderPass*>(obj);
 
   std::array<VkAttachmentDescription, 2> attachments{};
   // Color attachment.
   attachments[0].flags = 0;
-  attachments[0].format = BluCat::core.vk_swapchain->image_format;
+  attachments[0].format = BluCat::INT::core.vk_swapchain->image_format;
   attachments[0].samples = VK_SAMPLE_COUNT_1_BIT;
   attachments[0].loadOp = VK_ATTACHMENT_LOAD_OP_CLEAR;
   attachments[0].storeOp = VK_ATTACHMENT_STORE_OP_STORE;
@@ -95,7 +95,7 @@ load_3d(void *obj)
   render_pass_info.pDependencies = &dependency;
 
   if(vkCreateRenderPass(
-       BluCat::core.vk_device_with_swapchain->device, &render_pass_info,
+       BluCat::INT::core.vk_device_with_swapchain->device, &render_pass_info,
 			 nullptr, &self->pipeline_3d) != VK_SUCCESS)
     throw CommandError{"Failed to create Vulkan Render Pass 3D."};
 }
@@ -103,21 +103,21 @@ load_3d(void *obj)
 void
 unload_3d(void *obj)
 {
-  auto self = static_cast<BluCat::RenderPass*>(obj);
+  auto self = static_cast<BluCat::GRA::RenderPass*>(obj);
 
   vkDestroyRenderPass(
-    BluCat::core.vk_device_with_swapchain->device, self->pipeline_3d, nullptr);
+    BluCat::INT::core.vk_device_with_swapchain->device, self->pipeline_3d, nullptr);
 }
 
 void
 load_2d(void *obj)
 {
-  auto self = static_cast<BluCat::RenderPass*>(obj);
+  auto self = static_cast<BluCat::GRA::RenderPass*>(obj);
 
   std::array<VkAttachmentDescription, 1> attachments{};
   // Color attachment.
   attachments[0].flags = 0;
-  attachments[0].format = BluCat::core.vk_swapchain->image_format;
+  attachments[0].format = BluCat::INT::core.vk_swapchain->image_format;
   attachments[0].samples = VK_SAMPLE_COUNT_1_BIT;
   attachments[0].loadOp = VK_ATTACHMENT_LOAD_OP_LOAD;
   attachments[0].storeOp = VK_ATTACHMENT_STORE_OP_STORE;
@@ -166,7 +166,7 @@ load_2d(void *obj)
   render_pass_info.pDependencies = &dependency;
 
   if(vkCreateRenderPass(
-       BluCat::core.vk_device_with_swapchain->device, &render_pass_info,
+       BluCat::INT::core.vk_device_with_swapchain->device, &render_pass_info,
        nullptr, &self->pipeline_2d) != VK_SUCCESS)
     throw CommandError{"Failed to create Vulkan Render Pass 2D."};
 }
@@ -174,10 +174,10 @@ load_2d(void *obj)
 void
 unload_2d(void *obj)
 {
-  auto self = static_cast<BluCat::RenderPass*>(obj);
+  auto self = static_cast<BluCat::GRA::RenderPass*>(obj);
 
   vkDestroyRenderPass(
-    BluCat::core.vk_device_with_swapchain->device, self->pipeline_2d, nullptr);
+    BluCat::INT::core.vk_device_with_swapchain->device, self->pipeline_2d, nullptr);
 }
 
 const CommandChain loader{
@@ -187,7 +187,7 @@ const CommandChain loader{
 
 }
 
-namespace BluCat
+namespace BluCat::GRA
 {
 
 RenderPass::RenderPass()
diff --git a/src/blucat/render_pass.hpp b/src/blu_cat/gra/render_pass.hpp
index d55f908..4187261 100644
--- a/src/blucat/render_pass.hpp
+++ b/src/blu_cat/gra/render_pass.hpp
@@ -14,12 +14,12 @@
  * limitations under the License.
  */
 
-#ifndef CANDY_GEAR_BLUCAT_RENDER_PASS_H
-#define CANDY_GEAR_BLUCAT_RENDER_PASS_H 1
+#ifndef BLU_CAT_GRA_RENDER_PASS_H
+#define BLU_CAT_GRA_RENDER_PASS_H 1
 
 #include "vulkan.hpp"
 
-namespace BluCat
+namespace BluCat::GRA
 {
 
 struct RenderPass
@@ -33,4 +33,4 @@ struct RenderPass
 
 }
 
-#endif /* CANDY_GEAR_BLUCAT_RENDER_PASS_H */
+#endif /* BLU_CAT_GRA_RENDER_PASS_H */
diff --git a/src/blucat/renderer.cpp b/src/blu_cat/gra/renderer.cpp
index 18d3976..ad66003 100644
--- a/src/blucat/renderer.cpp
+++ b/src/blu_cat/gra/renderer.cpp
@@ -18,7 +18,7 @@
 
 #include <array>
 
-#include "core.hpp"
+#include "../int/core.hpp"
 #include "uniform_data_object.hpp"
 
 namespace
@@ -27,7 +27,7 @@ namespace
 void
 load_descriptor_pool(void *obj)
 {
-  auto self = static_cast<BluCat::Renderer*>(obj);
+  auto self = static_cast<BluCat::GRA::Renderer*>(obj);
 
   uint32_t uniform_buffer_count = 0;
   for(auto &view : self->views_3d)
@@ -48,7 +48,7 @@ load_descriptor_pool(void *obj)
   pool_info.pPoolSizes = &descriptor_pool_size;
 
   if(vkCreateDescriptorPool(
-       BluCat::core.vk_device_with_swapchain->device, &pool_info, nullptr,
+       BluCat::INT::core.vk_device_with_swapchain->device, &pool_info, nullptr,
        &self->descriptor_pool) != VK_SUCCESS)
     throw CommandError{"Failed to create a Vulkan descriptor pool."};
 
@@ -61,29 +61,29 @@ load_descriptor_pool(void *obj)
 void
 unload_descriptor_pool(void *obj)
 {
-  auto self = static_cast<BluCat::Renderer*>(obj);
+  auto self = static_cast<BluCat::GRA::Renderer*>(obj);
 
   for(auto &view : self->views_3d) view->unload_descriptor_sets();
   for(auto &view : self->views_2d) view->unload_descriptor_sets();
 
   vkDestroyDescriptorPool(
-    BluCat::core.vk_device_with_swapchain->device, self->descriptor_pool,
+    BluCat::INT::core.vk_device_with_swapchain->device, self->descriptor_pool,
     nullptr);
 }
 
 void
 load_queue_family(void *obj)
 {
-  auto self = static_cast<BluCat::Renderer*>(obj);
+  auto self = static_cast<BluCat::GRA::Renderer*>(obj);
 
   self->queue_family =
-    BluCat::core.vk_device_with_swapchain->get_queue_family_with_presentation();
+    BluCat::INT::core.vk_device_with_swapchain->get_queue_family_with_presentation();
 }
 
 void
 load_command_pool(void *obj)
 {
-  auto self = static_cast<BluCat::Renderer*>(obj);
+  auto self = static_cast<BluCat::GRA::Renderer*>(obj);
 
   VkCommandPoolCreateInfo create_info{};
   create_info.sType = VK_STRUCTURE_TYPE_COMMAND_POOL_CREATE_INFO;
@@ -99,7 +99,7 @@ load_command_pool(void *obj)
 void
 unload_command_pool(void *obj)
 {
-  auto self = static_cast<BluCat::Renderer*>(obj);
+  auto self = static_cast<BluCat::GRA::Renderer*>(obj);
 
 	self->wait_frame();
   vkDestroyCommandPool(
@@ -109,7 +109,7 @@ unload_command_pool(void *obj)
 void
 load_draw_command_buffer(void *obj)
 {
-  auto self = static_cast<BluCat::Renderer*>(obj);
+  auto self = static_cast<BluCat::GRA::Renderer*>(obj);
 
   // FIXME: 3 is a magical number, triple buffering.
   self->draw_command_buffers.resize(3);
@@ -136,14 +136,14 @@ const CommandChain loader{
 
 }
 
-namespace BluCat
+namespace BluCat::GRA
 {
 
 Renderer::Renderer(std::vector<std::shared_ptr<View2D>> views_2d,
 		   std::vector<std::shared_ptr<View3D>> views_3d):
-  skeletal_models_to_draw{BluCat::core.vk_swapchain->images_count},
-  static_models_to_draw{BluCat::core.vk_swapchain->images_count},
-  sprites_3d_to_draw{BluCat::core.vk_swapchain->images_count},
+  skeletal_models_to_draw{BluCat::INT::core.vk_swapchain->images_count},
+  static_models_to_draw{BluCat::INT::core.vk_swapchain->images_count},
+  sprites_3d_to_draw{BluCat::INT::core.vk_swapchain->images_count},
   views_2d{views_2d},
   views_3d{views_3d}
 {
@@ -166,9 +166,9 @@ Renderer::~Renderer()
 void
 Renderer::wait_frame()
 {
-  vkWaitForFences(BluCat::core.vk_device_with_swapchain->device,
-		  BluCat::Swapchain::max_frames_in_flight,
-		  BluCat::core.vk_swapchain->in_flight_fences.data(), VK_TRUE,
+  vkWaitForFences(BluCat::INT::core.vk_device_with_swapchain->device,
+		  BluCat::GRA::Swapchain::max_frames_in_flight,
+		  BluCat::INT::core.vk_swapchain->in_flight_fences.data(), VK_TRUE,
 		  std::numeric_limits<uint64_t>::max());
 }
 
@@ -176,29 +176,29 @@ void
 Renderer::draw()
 {
   auto fence_status = vkGetFenceStatus(
-    BluCat::core.vk_device_with_swapchain->device,
-    BluCat::core.vk_swapchain->in_flight_fences[
-      BluCat::core.vk_swapchain->current_frame]);
+    BluCat::INT::core.vk_device_with_swapchain->device,
+    BluCat::INT::core.vk_swapchain->in_flight_fences[
+      BluCat::INT::core.vk_swapchain->current_frame]);
 
   if(fence_status == VK_SUCCESS)
   {
-    auto next_frame = BluCat::core.vk_swapchain->current_frame + 1;
+    auto next_frame = BluCat::INT::core.vk_swapchain->current_frame + 1;
     if(next_frame == Swapchain::max_frames_in_flight) next_frame = 0;
 
-    vkResetFences(core.vk_device_with_swapchain->device, 1,
-		  &BluCat::core.vk_swapchain->in_flight_fences[
-		    BluCat::core.vk_swapchain->current_frame]);
+    vkResetFences(INT::core.vk_device_with_swapchain->device, 1,
+		  &BluCat::INT::core.vk_swapchain->in_flight_fences[
+		    BluCat::INT::core.vk_swapchain->current_frame]);
 
     uint32_t image_index;
     vkAcquireNextImageKHR(
-      BluCat::core.vk_device_with_swapchain->device,
-      BluCat::core.vk_swapchain->swapchain,
+      BluCat::INT::core.vk_device_with_swapchain->device,
+      BluCat::INT::core.vk_swapchain->swapchain,
 			std::numeric_limits<uint64_t>::max(),
-      BluCat::core.vk_swapchain->image_available_semaphores[
-	BluCat::core.vk_swapchain->current_frame], VK_NULL_HANDLE, &image_index);
+      BluCat::INT::core.vk_swapchain->image_available_semaphores[
+	BluCat::INT::core.vk_swapchain->current_frame], VK_NULL_HANDLE, &image_index);
 
     VkCommandBuffer draw_command_buffer =
-      this->draw_command_buffers[BluCat::core.vk_swapchain->current_frame];
+      this->draw_command_buffers[BluCat::INT::core.vk_swapchain->current_frame];
     vkResetCommandBuffer(draw_command_buffer, 0);
 
     // Begin command buffer.
@@ -222,7 +222,7 @@ Renderer::draw()
 	UDOWorld3D_Vert ubo_world_3d_vert{};
 	ubo_world_3d_vert.ambient_light_color =
 	  glm::vec4{0.25, 0.25, 0.25, 1.0};
-	BluCat::core.vk_light->ub_world_vert[image_index].copy_data(
+	BluCat::INT::core.vk_light->ub_world_vert[image_index].copy_data(
 	  &ubo_world_3d_vert);
 
 	UDOWorld3D_Frag ubo_world_3d_frag{};
@@ -230,20 +230,20 @@ Renderer::draw()
 	  glm::vec3{-0.57735, 0.57735, -0.57735};
 	ubo_world_3d_frag.directional_light_color =
 	  glm::vec4{0.8, 0.8, 0.8, 1.0};
-	BluCat::core.vk_light->ub_world_frag[image_index].copy_data(
+	BluCat::INT::core.vk_light->ub_world_frag[image_index].copy_data(
 	  &ubo_world_3d_frag);
       }
 
       VkRenderPassBeginInfo render_pass_begin{};
       render_pass_begin.sType = VK_STRUCTURE_TYPE_RENDER_PASS_BEGIN_INFO;
       render_pass_begin.pNext = nullptr;
-      render_pass_begin.renderPass = BluCat::core.vk_render_pass->pipeline_3d;
+      render_pass_begin.renderPass = BluCat::INT::core.vk_render_pass->pipeline_3d;
       render_pass_begin.framebuffer =
-	BluCat::core.vk_framebuffer->pipeline_3d[image_index];
+	BluCat::INT::core.vk_framebuffer->pipeline_3d[image_index];
       render_pass_begin.renderArea.offset = {0, 0};
       render_pass_begin.renderArea.extent = {
-	static_cast<uint32_t>(BluCat::core.display_width),
-	static_cast<uint32_t>(BluCat::core.display_height)};
+	static_cast<uint32_t>(BluCat::INT::core.display_width),
+	static_cast<uint32_t>(BluCat::INT::core.display_height)};
       render_pass_begin.clearValueCount = clear_values.size();
       render_pass_begin.pClearValues = clear_values.data();
 
@@ -271,20 +271,20 @@ Renderer::draw()
 				vkCmdSetScissor(draw_command_buffer, 0, 1, &vk_scissor);
 			}
 
-			BluCat::core.vk_graphics_pipeline_3d->draw(
-				view, draw_command_buffer, BluCat::core.vk_swapchain->current_frame,
+			BluCat::INT::core.vk_graphics_pipeline_3d->draw(
+				view, draw_command_buffer, BluCat::INT::core.vk_swapchain->current_frame,
 				image_index);
 
-			BluCat::core.vk_graphics_pipeline_sprite_3d->draw(
-				view, draw_command_buffer, BluCat::core.vk_swapchain->current_frame,
+			BluCat::INT::core.vk_graphics_pipeline_sprite_3d->draw(
+				view, draw_command_buffer, BluCat::INT::core.vk_swapchain->current_frame,
 				image_index);
 
-			BluCat::core.vk_graphics_pipeline_3d_skeletal->draw(
-				view, draw_command_buffer, BluCat::core.vk_swapchain->current_frame,
+			BluCat::INT::core.vk_graphics_pipeline_3d_skeletal->draw(
+				view, draw_command_buffer, BluCat::INT::core.vk_swapchain->current_frame,
 				image_index);
 
 			{ // Update view uniform buffers
-				BluCat::UDOView3D ubo_view_3d{};
+				BluCat::GRA::UDOView3D ubo_view_3d{};
 
 				// View matrix.
 				glm::mat4 translation_matrix{1.0f};
@@ -309,13 +309,13 @@ Renderer::draw()
       VkRenderPassBeginInfo render_pass_begin{};
       render_pass_begin.sType = VK_STRUCTURE_TYPE_RENDER_PASS_BEGIN_INFO;
       render_pass_begin.pNext = nullptr;
-      render_pass_begin.renderPass = BluCat::core.vk_render_pass->pipeline_2d;
+      render_pass_begin.renderPass = BluCat::INT::core.vk_render_pass->pipeline_2d;
       render_pass_begin.framebuffer =
-	BluCat::core.vk_framebuffer->pipeline_2d[image_index];
+	BluCat::INT::core.vk_framebuffer->pipeline_2d[image_index];
       render_pass_begin.renderArea.offset = {0, 0};
       render_pass_begin.renderArea.extent = {
-	static_cast<uint32_t>(BluCat::core.display_width),
-	static_cast<uint32_t>(BluCat::core.display_height)};
+	static_cast<uint32_t>(BluCat::INT::core.display_width),
+	static_cast<uint32_t>(BluCat::INT::core.display_height)};
       render_pass_begin.clearValueCount = 0;
       render_pass_begin.pClearValues = nullptr;
 
@@ -326,25 +326,25 @@ Renderer::draw()
 
     { // 2D solid drawing
       for(auto &view: this->views_2d)
-	BluCat::core.vk_graphics_pipeline_2d_solid->draw(
-	  view, draw_command_buffer, BluCat::core.vk_swapchain->current_frame,
+	BluCat::INT::core.vk_graphics_pipeline_2d_solid->draw(
+	  view, draw_command_buffer, BluCat::INT::core.vk_swapchain->current_frame,
 	  next_frame, image_index);
 
       for(auto &view: this->views_3d)
-	BluCat::core.vk_graphics_pipeline_2d_solid->draw(
-	  view, draw_command_buffer, BluCat::core.vk_swapchain->current_frame,
+	BluCat::INT::core.vk_graphics_pipeline_2d_solid->draw(
+	  view, draw_command_buffer, BluCat::INT::core.vk_swapchain->current_frame,
 	  next_frame, image_index);
     }
 
     { // 2D wired drawing
       for(auto &view: this->views_2d)
-	BluCat::core.vk_graphics_pipeline_2d_wired->draw(
-	  view, draw_command_buffer, BluCat::core.vk_swapchain->current_frame,
+	BluCat::INT::core.vk_graphics_pipeline_2d_wired->draw(
+	  view, draw_command_buffer, BluCat::INT::core.vk_swapchain->current_frame,
 	  next_frame, image_index);
 
       for(auto &view: this->views_3d)
-	BluCat::core.vk_graphics_pipeline_2d_wired->draw(
-	  view, draw_command_buffer, BluCat::core.vk_swapchain->current_frame,
+	BluCat::INT::core.vk_graphics_pipeline_2d_wired->draw(
+	  view, draw_command_buffer, BluCat::INT::core.vk_swapchain->current_frame,
 	  next_frame, image_index);
     }
 
@@ -359,13 +359,13 @@ Renderer::draw()
       auto queue{this->queue_family->get_queue()};
 
       VkSemaphore wait_semaphores[]{
-	BluCat::core.vk_swapchain->image_available_semaphores[
-	  BluCat::core.vk_swapchain->current_frame]};
+	BluCat::INT::core.vk_swapchain->image_available_semaphores[
+	  BluCat::INT::core.vk_swapchain->current_frame]};
       VkPipelineStageFlags wait_stages[] =
 	{VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT};
       VkSemaphore signal_semaphores[]{
-	BluCat::core.vk_swapchain->render_finished_semaphores[
-	  BluCat::core.vk_swapchain->current_frame]};
+	BluCat::INT::core.vk_swapchain->render_finished_semaphores[
+	  BluCat::INT::core.vk_swapchain->current_frame]};
 
       VkSubmitInfo submit_info{};
       submit_info.sType = VK_STRUCTURE_TYPE_SUBMIT_INFO;
@@ -379,11 +379,11 @@ Renderer::draw()
       submit_info.pSignalSemaphores = signal_semaphores;
 
       if(vkQueueSubmit(
-	   queue.queue, 1, &submit_info, BluCat::core.vk_swapchain->in_flight_fences[
-	     BluCat::core.vk_swapchain->current_frame]) != VK_SUCCESS)
+	   queue.queue, 1, &submit_info, BluCat::INT::core.vk_swapchain->in_flight_fences[
+	     BluCat::INT::core.vk_swapchain->current_frame]) != VK_SUCCESS)
 	throw std::runtime_error{"Failed to submit draw command buffer."};
 
-      VkSwapchainKHR swap_chains[]{BluCat::core.vk_swapchain->swapchain};
+      VkSwapchainKHR swap_chains[]{BluCat::INT::core.vk_swapchain->swapchain};
 
       VkPresentInfoKHR present_info{};
       present_info.sType = VK_STRUCTURE_TYPE_PRESENT_INFO_KHR;
@@ -403,22 +403,22 @@ Renderer::draw()
       this->skeletal_models_to_draw[next_frame].clear();
       this->static_models_to_draw[next_frame].clear();
       this->sprites_3d_to_draw[next_frame].clear();
-      BluCat::core.vk_swapchain->current_frame = next_frame;
+      BluCat::INT::core.vk_swapchain->current_frame = next_frame;
     }
   }
   else
   {
     // Clear images for the current frame because we are skipping this frame.
     this->skeletal_models_to_draw[
-			BluCat::core.vk_swapchain->current_frame].clear();
+			BluCat::INT::core.vk_swapchain->current_frame].clear();
     this->static_models_to_draw[
-			BluCat::core.vk_swapchain->current_frame].clear();
+			BluCat::INT::core.vk_swapchain->current_frame].clear();
     this->sprites_3d_to_draw[
-			BluCat::core.vk_swapchain->current_frame].clear();
+			BluCat::INT::core.vk_swapchain->current_frame].clear();
     for(auto &view: this->views_2d)
-      view->sprites_to_draw[BluCat::core.vk_swapchain->current_frame].clear();
+      view->sprites_to_draw[BluCat::INT::core.vk_swapchain->current_frame].clear();
     for(auto &view: this->views_3d)
-      view->sprites_to_draw[BluCat::core.vk_swapchain->current_frame].clear();
+      view->sprites_to_draw[BluCat::INT::core.vk_swapchain->current_frame].clear();
   }
 }
 
diff --git a/src/blucat/renderer.hpp b/src/blu_cat/gra/renderer.hpp
index 55b0727..0a3d15f 100644
--- a/src/blucat/renderer.hpp
+++ b/src/blu_cat/gra/renderer.hpp
@@ -14,8 +14,8 @@
  * limitations under the License.
  */
 
-#ifndef CANDY_GEAR_BLUCAT_RENDERER_H
-#define CANDY_GEAR_BLUCAT_RENDERER_H 1
+#ifndef BLU_CAT_GRA_RENDERER_H
+#define BLU_CAT_GRA_RENDERER_H 1
 
 #include <initializer_list>
 #include <memory>
@@ -31,7 +31,7 @@
 #include "view_2d.hpp"
 #include "view_3d.hpp"
 
-namespace BluCat
+namespace BluCat::GRA
 {
 
 struct Renderer
@@ -72,4 +72,4 @@ struct Renderer
 
 }
 
-#endif /* CANDY_GEAR_BLUCAT_RENDERER_H */
+#endif /* BLU_CAT_GRA_RENDERER_H */
diff --git a/src/blucat/skeletal_mesh.cpp b/src/blu_cat/gra/skeletal_mesh.cpp
index d4fbfe7..89d701b 100644
--- a/src/blucat/skeletal_mesh.cpp
+++ b/src/blu_cat/gra/skeletal_mesh.cpp
@@ -17,8 +17,8 @@
 #include "skeletal_mesh.hpp"
 
 #include "binary_reader.hpp"
-#include "command.hpp"
-#include "core.hpp"
+#include "../com/command.hpp"
+#include "../int/core.hpp"
 #include "skeletal_mesh_vertex.hpp"
 
 namespace
@@ -29,19 +29,19 @@ namespace
 struct MeshBuilder
 {
   std::string mesh_path;
-  BluCat::SkeletalMesh *mesh;
+  BluCat::GRA::SkeletalMesh *mesh;
 
-  MeshBuilder(BluCat::SkeletalMesh *m, std::string mp);
-  MeshBuilder(BluCat::SkeletalMesh *m, const char* mp);
+  MeshBuilder(BluCat::GRA::SkeletalMesh *m, std::string mp);
+  MeshBuilder(BluCat::GRA::SkeletalMesh *m, const char* mp);
 };
 
-MeshBuilder::MeshBuilder(BluCat::SkeletalMesh *m, std::string mp):
+MeshBuilder::MeshBuilder(BluCat::GRA::SkeletalMesh *m, std::string mp):
   mesh{m},
   mesh_path{mp}
 {
 }
 
-MeshBuilder::MeshBuilder(BluCat::SkeletalMesh *m, const char *mp):
+MeshBuilder::MeshBuilder(BluCat::GRA::SkeletalMesh *m, const char *mp):
   MeshBuilder{m, std::string(mp)}
 {
 }
@@ -54,11 +54,11 @@ load_mesh(void *obj)
   BinaryReader input{self->mesh_path};
 
   self->mesh->queue_family =
-    BluCat::core.vk_device_with_swapchain->get_queue_family_with_graphics();
+    BluCat::INT::core.vk_device_with_swapchain->get_queue_family_with_graphics();
 
   { // Load vertexes.
     auto vertex_count{input.read_ui32()};
-    std::vector<BluCat::SkeletalMeshVertex> vertexes{vertex_count};
+    std::vector<BluCat::GRA::SkeletalMeshVertex> vertexes{vertex_count};
 
     for(auto i{0}; i < vertex_count; i++)
     {
@@ -66,20 +66,20 @@ load_mesh(void *obj)
       vertexes[i].normal = input.read_vec3();
       vertexes[i].texture_coord = input.read_vec2();
 
-      for(auto ii{0}; ii < BluCat::SKELETAL_MESH_MAX_NUM_OF_INFLUENCING_BONES;
+      for(auto ii{0}; ii < BluCat::GRA::SKELETAL_MESH_MAX_NUM_OF_INFLUENCING_BONES;
 	  ii++)
 	vertexes[i].bone_ids[ii] = input.read_ui32();
 
-      for(auto ii{0}; ii < BluCat::SKELETAL_MESH_MAX_NUM_OF_INFLUENCING_BONES;
+      for(auto ii{0}; ii < BluCat::GRA::SKELETAL_MESH_MAX_NUM_OF_INFLUENCING_BONES;
 	  ii++)
 	vertexes[i].bone_weights[ii] = input.read_float();
     }
 
     void *vertexes_data{vertexes.data()};
     size_t vertexes_size = sizeof(vertexes[0]) * vertexes.size();
-    self->mesh->source_vertex_buffer = new BluCat::SourceBuffer{
+    self->mesh->source_vertex_buffer = new BluCat::GRA::SourceBuffer{
       self->mesh->queue_family->device, vertexes_data, vertexes_size};
-    self->mesh->vertex_buffer = new BluCat::DestinationBuffer{
+    self->mesh->vertex_buffer = new BluCat::GRA::DestinationBuffer{
       self->mesh->queue_family, self->mesh->source_vertex_buffer,
       VK_BUFFER_USAGE_VERTEX_BUFFER_BIT};
   }
@@ -93,9 +93,9 @@ load_mesh(void *obj)
 
     void *indexes_data{indexes.data()};
     size_t indexes_size{sizeof(indexes[0]) * indexes.size()};
-    BluCat::SourceBuffer source_index_buffer{
+    BluCat::GRA::SourceBuffer source_index_buffer{
       self->mesh->queue_family->device, indexes_data, indexes_size};
-    self->mesh->index_buffer = new BluCat::DestinationBuffer{
+    self->mesh->index_buffer = new BluCat::GRA::DestinationBuffer{
       self->mesh->queue_family, &source_index_buffer,
       VK_BUFFER_USAGE_INDEX_BUFFER_BIT};
   }
@@ -118,7 +118,7 @@ load_mesh(void *obj)
       auto ticks_per_second{input.read_double()};
 
       auto num_bone_transforms{input.read_ui32()};
-      std::vector<BluCat::BoneTransform> *bone_transforms =
+      std::vector<BluCat::GRA::BoneTransform> *bone_transforms =
 	&(self->mesh->animations[i].bone_transforms);
       bone_transforms->resize(num_bone_transforms);
       for(uint32_t bone_transform_index{0};
@@ -127,7 +127,7 @@ load_mesh(void *obj)
 	auto bone_id{input.read_ui32()};
 
 	auto num_positions{input.read_ui32()};
-	BluCat::Channel<glm::vec3> *positions =
+	BluCat::GRA::Channel<glm::vec3> *positions =
 	  &((*bone_transforms)[bone_transform_index].positions);
 	for(auto position_key_index{0}; position_key_index < num_positions;
 	    position_key_index++)
@@ -139,7 +139,7 @@ load_mesh(void *obj)
 	}
 
 	auto num_rotations{input.read_ui32()};
-	BluCat::Channel<glm::quat> *rotations =
+	BluCat::GRA::Channel<glm::quat> *rotations =
 	  &((*bone_transforms)[bone_transform_index].rotations);
 	for(auto rotation_key_index{0}; rotation_key_index < num_rotations;
 	    rotation_key_index++)
@@ -151,7 +151,7 @@ load_mesh(void *obj)
 	}
 
 	auto num_scales{input.read_ui32()};
-	BluCat::Channel<glm::vec3> *scales =
+	BluCat::GRA::Channel<glm::vec3> *scales =
 	  &((*bone_transforms)[bone_transform_index].scales);
 	for(auto scaling_key_index{0}; scaling_key_index < num_scales;
 	    scaling_key_index++)
@@ -181,7 +181,7 @@ static const CommandChain loader{
 
 }
 
-namespace BluCat
+namespace BluCat::GRA
 {
 
 SkeletalMesh::SkeletalMesh(std::string mesh_path)
diff --git a/src/blucat/skeletal_mesh.hpp b/src/blu_cat/gra/skeletal_mesh.hpp
index 98506d7..f586ea3 100644
--- a/src/blucat/skeletal_mesh.hpp
+++ b/src/blu_cat/gra/skeletal_mesh.hpp
@@ -14,8 +14,8 @@
  * limitations under the License.
  */
 
-#ifndef CANDY_GEAR_BLUCAT_SKELETAL_MESH_H
-#define CANDY_GEAR_BLUCAT_SKELETAL_MESH_H 1
+#ifndef BLU_CAT_GRA_SKELETAL_MESH_H
+#define BLU_CAT_GRA_SKELETAL_MESH_H 1
 
 #include <string>
 #include <vector>
@@ -27,7 +27,7 @@
 #include "uniform_buffer.hpp"
 #include "texture.hpp"
 
-namespace BluCat
+namespace BluCat::GRA
 {
 
 struct SkeletalMesh
@@ -49,4 +49,4 @@ struct SkeletalMesh
 
 }
 
-#endif /* CANDY_GEAR_BLUCAT_SKELETAL_MESH_H */
+#endif /* BLU_CAT_GRA_SKELETAL_MESH_H */
diff --git a/src/blucat/skeletal_mesh_vertex.hpp b/src/blu_cat/gra/skeletal_mesh_vertex.hpp
index 2e8a56f..1bd70ad 100644
--- a/src/blucat/skeletal_mesh_vertex.hpp
+++ b/src/blu_cat/gra/skeletal_mesh_vertex.hpp
@@ -14,12 +14,12 @@
  * limitations under the License.
  */
 
-#ifndef CANDY_GEAR_BLUCAT_SKELETAL_MESH_VERTEX_H
-#define CANDY_GEAR_BLUCAT_SKELETAL_MESH_VERTEX_H 1
+#ifndef BLU_CAT_GRA_SKELETAL_MESH_VERTEX_H
+#define BLU_CAT_GRA_SKELETAL_MESH_VERTEX_H 1
 
 #include "vulkan.hpp"
 
-namespace BluCat
+namespace BluCat::GRA
 {
 
 // This variable define the maximum ammount of bones that can influence a
@@ -39,4 +39,4 @@ struct SkeletalMeshVertex
 
 }
 
-#endif /* CANDY_GEAR_BLUCAT_SKELETAL_MESH_VERTEX_H */
+#endif /* BLU_CAT_GRA_SKELETAL_MESH_VERTEX_H */
diff --git a/src/blucat/skeletal_model.cpp b/src/blu_cat/gra/skeletal_model.cpp
index fa46044..b58982d 100644
--- a/src/blucat/skeletal_model.cpp
+++ b/src/blu_cat/gra/skeletal_model.cpp
@@ -16,7 +16,7 @@
 
 #include "skeletal_model.hpp"
 
-#include "core.hpp"
+#include "../int/core.hpp"
 #include "uniform_data_object.hpp"
 
 namespace
@@ -25,15 +25,15 @@ namespace
 void
 load_uniform_buffers(void *obj)
 {
-  auto self = static_cast<BluCat::SkeletalModel*>(obj);
+  auto self = static_cast<BluCat::GRA::SkeletalModel*>(obj);
 
   try
   {
-    self->uniform_buffers.reserve(BluCat::core.vk_swapchain->images_count);
-    for(auto i{0}; i < BluCat::core.vk_swapchain->images_count; i++)
+    self->uniform_buffers.reserve(BluCat::INT::core.vk_swapchain->images_count);
+    for(auto i{0}; i < BluCat::INT::core.vk_swapchain->images_count; i++)
       self->uniform_buffers.emplace_back(
-				BluCat::core.vk_device_with_swapchain,
-				sizeof(BluCat::UDOSkeletalModel));
+				BluCat::INT::core.vk_device_with_swapchain,
+				sizeof(BluCat::GRA::UDOSkeletalModel));
   }
   catch(const std::exception& e)
   {
@@ -44,7 +44,7 @@ load_uniform_buffers(void *obj)
 void
 unload_uniform_buffers(void *obj)
 {
-  auto self = static_cast<BluCat::SkeletalModel*>(obj);
+  auto self = static_cast<BluCat::GRA::SkeletalModel*>(obj);
 
   self->uniform_buffers.clear();
 }
@@ -52,7 +52,7 @@ unload_uniform_buffers(void *obj)
 void
 load_descriptor_set_pool(void *obj)
 {
-  auto self = static_cast<BluCat::SkeletalModel*>(obj);
+  auto self = static_cast<BluCat::GRA::SkeletalModel*>(obj);
 
   std::array<VkDescriptorPoolSize, 1> descriptor_pool_sizes{};
   descriptor_pool_sizes[0].type = VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER;
@@ -76,7 +76,7 @@ load_descriptor_set_pool(void *obj)
 void
 unload_descriptor_set_pool(void *obj)
 {
-  auto self = static_cast<BluCat::SkeletalModel*>(obj);
+  auto self = static_cast<BluCat::GRA::SkeletalModel*>(obj);
 
   vkDestroyDescriptorPool(
     self->skeletal_mesh->queue_family->device->device, self->descriptor_pool,
@@ -86,11 +86,11 @@ unload_descriptor_set_pool(void *obj)
 void
 load_descriptor_sets(void *obj)
 {
-  auto self = static_cast<BluCat::SkeletalModel*>(obj);
+  auto self = static_cast<BluCat::GRA::SkeletalModel*>(obj);
 
   std::vector<VkDescriptorSetLayout> layouts(
-    BluCat::core.vk_swapchain->images_count,
-    BluCat::core.vk_descriptor_set_layout->model);
+    BluCat::INT::core.vk_swapchain->images_count,
+    BluCat::INT::core.vk_descriptor_set_layout->model);
 
   VkDescriptorSetAllocateInfo alloc_info{};
   alloc_info.sType = VK_STRUCTURE_TYPE_DESCRIPTOR_SET_ALLOCATE_INFO;
@@ -108,14 +108,14 @@ load_descriptor_sets(void *obj)
 void
 load_buffers_to_descriptor_sets(void *obj)
 {
-  auto self = static_cast<BluCat::SkeletalModel*>(obj);
+  auto self = static_cast<BluCat::GRA::SkeletalModel*>(obj);
 
   for(auto i{0}; i < self->uniform_buffers.size(); i++)
   {
     VkDescriptorBufferInfo buffer_info{};
     buffer_info.buffer = self->uniform_buffers[i].buffer;
     buffer_info.offset = 0;
-    buffer_info.range = sizeof(BluCat::UDOSkeletalModel);
+    buffer_info.range = sizeof(BluCat::GRA::UDOSkeletalModel);
 
     std::array<VkWriteDescriptorSet, 1> write_descriptors{};
     write_descriptors[0].sType = VK_STRUCTURE_TYPE_WRITE_DESCRIPTOR_SET;
@@ -129,7 +129,7 @@ load_buffers_to_descriptor_sets(void *obj)
     write_descriptors[0].pTexelBufferView = nullptr;
 
     vkUpdateDescriptorSets(
-      BluCat::core.vk_device_with_swapchain->device, write_descriptors.size(),
+      BluCat::INT::core.vk_device_with_swapchain->device, write_descriptors.size(),
       write_descriptors.data(), 0, nullptr);
   }
 }
@@ -143,7 +143,7 @@ static const CommandChain loader{
 
 }
 
-namespace BluCat
+namespace BluCat::GRA
 {
 
 SkeletalModel::SkeletalModel(
@@ -172,7 +172,7 @@ SkeletalModel::~SkeletalModel()
 void
 SkeletalModel::tick(float delta)
 {
-  BluCat::Animation *current_animation =
+  BluCat::GRA::Animation *current_animation =
     &this->skeletal_mesh->animations[this->animation_index];
 
   { // update time
@@ -180,7 +180,7 @@ SkeletalModel::tick(float delta)
     if(this->animation_time > current_animation->final_time)
     {
       this->animation_time -= current_animation->final_time;
-      for(BluCat::BoneTransform &bone_transform:
+      for(BluCat::GRA::BoneTransform &bone_transform:
 	    current_animation->bone_transforms)
       {
 	bone_transform.positions.current_index = 0;
@@ -192,7 +192,7 @@ SkeletalModel::tick(float delta)
 
   for(int i{0}; i < current_animation->bone_transforms.size(); i++)
   {
-    BluCat::BoneTransform *bone_transform = &current_animation->bone_transforms[i];
+    BluCat::GRA::BoneTransform *bone_transform = &current_animation->bone_transforms[i];
 
     auto position{bone_transform->positions.interpolate(
 	this->animation_time,
diff --git a/src/blucat/skeletal_model.hpp b/src/blu_cat/gra/skeletal_model.hpp
index 03be8e5..73998cb 100644
--- a/src/blucat/skeletal_model.hpp
+++ b/src/blu_cat/gra/skeletal_model.hpp
@@ -14,8 +14,8 @@
  * limitations under the License.
  */
 
-#ifndef CANDY_GEAR_BLUCAT_SKELETAL_MODEL_H
-#define CANDY_GEAR_BLUCAT_SKELETAL_MODEL_H 1
+#ifndef BLU_CAT_GRA_SKELETAL_MODEL_H
+#define BLU_CAT_GRA_SKELETAL_MODEL_H 1
 
 #include <memory>
 #include <vector>
@@ -23,7 +23,7 @@
 #include "vulkan.hpp"
 #include "skeletal_mesh.hpp"
 
-namespace BluCat
+namespace BluCat::GRA
 {
 
 struct SkeletalModel
@@ -52,4 +52,4 @@ struct SkeletalModel
 
 }
 
-#endif /* CANDY_GEAR_BLUCAT_SKELETAL_MODEL_H */
+#endif /* BLU_CAT_GRA_SKELETAL_MODEL_H */
diff --git a/src/blucat/source_buffer.cpp b/src/blu_cat/gra/source_buffer.cpp
index 41c40b9..18f263f 100644
--- a/src/blucat/source_buffer.cpp
+++ b/src/blu_cat/gra/source_buffer.cpp
@@ -18,7 +18,7 @@
 
 #include <cstring>
 
-namespace BluCat
+namespace BluCat::GRA
 {
 
 SourceBuffer::SourceBuffer(Device *device, void *data, size_t data_size)
@@ -31,7 +31,7 @@ SourceBuffer::SourceBuffer(Device *device, void *data, size_t data_size)
 
   try
   {
-    BluCat::BaseBuffer::loader.execute(static_cast<BluCat::BaseBuffer*>(this));
+    BluCat::GRA::BaseBuffer::loader.execute(static_cast<BluCat::GRA::BaseBuffer*>(this));
   }
   catch(const CommandError &command_error)
   {
@@ -71,7 +71,7 @@ SourceBuffer::operator=(SourceBuffer &&that)
 
 SourceBuffer::~SourceBuffer()
 {
-  BluCat::BaseBuffer::loader.revert(static_cast<BluCat::BaseBuffer*>(this));
+  BluCat::GRA::BaseBuffer::loader.revert(static_cast<BluCat::GRA::BaseBuffer*>(this));
 }
 
 void
diff --git a/src/blucat/source_buffer.hpp b/src/blu_cat/gra/source_buffer.hpp
index dd52acc..4eecec9 100644
--- a/src/blucat/source_buffer.hpp
+++ b/src/blu_cat/gra/source_buffer.hpp
@@ -14,12 +14,12 @@
  * limitations under the License.
  */
 
-#ifndef CANDY_GEAR_BLUCAT_SOURCE_BUFFER_H
-#define CANDY_GEAR_BLUCAT_SOURCE_BUFFER_H 1
+#ifndef BLU_CAT_GRA_SOURCE_BUFFER_H
+#define BLU_CAT_GRA_SOURCE_BUFFER_H 1
 
 #include "base_buffer.hpp"
 
-namespace BluCat
+namespace BluCat::GRA
 {
 
 struct SourceBuffer: public BaseBuffer
@@ -42,4 +42,4 @@ struct SourceBuffer: public BaseBuffer
 
 }
 
-#endif /* CANDY_GEAR_BLUCAT_SOURCE_BUFFER_H */
+#endif /* BLU_CAT_GRA_SOURCE_BUFFER_H */
diff --git a/src/blucat/sprite.cpp b/src/blu_cat/gra/sprite.cpp
index 0c66a27..ee64efe 100644
--- a/src/blucat/sprite.cpp
+++ b/src/blu_cat/gra/sprite.cpp
@@ -18,7 +18,7 @@
 
 #include <array>
 
-#include "core.hpp"
+#include "../int/core.hpp"
 #include "sprite.hpp"
 #include "uniform_data_object.hpp"
 
@@ -27,13 +27,13 @@ namespace
 
 struct SpriteBuilder
 {
-  BluCat::Sprite *sprite;
+  BluCat::GRA::Sprite *sprite;
   const glm::vec4 &rect;
 
-  SpriteBuilder(BluCat::Sprite *sprite, const glm::vec4 &rect);
+  SpriteBuilder(BluCat::GRA::Sprite *sprite, const glm::vec4 &rect);
 };
 
-SpriteBuilder::SpriteBuilder(BluCat::Sprite *sprite, const glm::vec4 &rect):
+SpriteBuilder::SpriteBuilder(BluCat::GRA::Sprite *sprite, const glm::vec4 &rect):
   sprite{sprite},
   rect{rect}
 {
@@ -45,9 +45,9 @@ load_mesh(void *obj)
   auto self = static_cast<SpriteBuilder*>(obj);
 
   self->sprite->queue_family =
-    BluCat::core.vk_device_with_swapchain->get_queue_family_with_graphics();
+    BluCat::INT::core.vk_device_with_swapchain->get_queue_family_with_graphics();
 
-  glm::vec2 rect[BluCat::Sprite::vertex_count]{
+  glm::vec2 rect[BluCat::GRA::Sprite::vertex_count]{
     glm::vec2{self->rect.x, self->rect.y},
     glm::vec2{self->rect.x, self->rect.w},
     glm::vec2{self->rect.z, self->rect.y},
@@ -56,10 +56,10 @@ load_mesh(void *obj)
 
   void *vertexes_data{&rect};
   static const size_t vertexes_size =
-    sizeof(glm::vec2) * BluCat::Sprite::vertex_count;
-  self->sprite->source_buffer = new BluCat::SourceBuffer{
+    sizeof(glm::vec2) * BluCat::GRA::Sprite::vertex_count;
+  self->sprite->source_buffer = new BluCat::GRA::SourceBuffer{
     self->sprite->queue_family->device, vertexes_data, vertexes_size};
-  self->sprite->vertex_buffer = new BluCat::DestinationBuffer{
+  self->sprite->vertex_buffer = new BluCat::GRA::DestinationBuffer{
     self->sprite->queue_family, self->sprite->source_buffer,
     VK_BUFFER_USAGE_VERTEX_BUFFER_BIT};
 }
@@ -79,7 +79,7 @@ static const CommandChain loader{
 
 }
 
-namespace BluCat
+namespace BluCat::GRA
 {
 
 Sprite::Sprite(std::shared_ptr<Texture> texture, const glm::vec4 &rect):
diff --git a/src/blucat/sprite.hpp b/src/blu_cat/gra/sprite.hpp
index 303beca..1834b22 100644
--- a/src/blucat/sprite.hpp
+++ b/src/blu_cat/gra/sprite.hpp
@@ -14,8 +14,8 @@
  * limitations under the License.
  */
 
-#ifndef CANDY_GEAR_BLUCAT_SPRITE_H
-#define CANDY_GEAR_BLUCAT_SPRITE_H 1
+#ifndef BLU_CAT_GRA_SPRITE_H
+#define BLU_CAT_GRA_SPRITE_H 1
 
 #include <memory>
 #include <unordered_map>
@@ -27,7 +27,7 @@
 #include "uniform_buffer.hpp"
 #include "texture.hpp"
 
-namespace BluCat
+namespace BluCat::GRA
 {
 
 struct Sprite
@@ -47,4 +47,4 @@ struct Sprite
 
 }
 
-#endif /* CANDY_GEAR_BLUCAT_SPRITE_H */
+#endif /* BLU_CAT_GRA_SPRITE_H */
diff --git a/src/blucat/sprite_3d.cpp b/src/blu_cat/gra/sprite_3d.cpp
index dab97e2..fc994a6 100644
--- a/src/blucat/sprite_3d.cpp
+++ b/src/blu_cat/gra/sprite_3d.cpp
@@ -16,7 +16,7 @@
 
 #include "sprite_3d.hpp"
 
-#include "core.hpp"
+#include "../int/core.hpp"
 #include "uniform_data_object.hpp"
 
 namespace
@@ -25,14 +25,14 @@ namespace
 void
 load_uniform_buffers(void *obj)
 {
-  auto self = static_cast<BluCat::Sprite3D*>(obj);
+  auto self = static_cast<BluCat::GRA::Sprite3D*>(obj);
 
   try
   {
-    self->uniform_buffers.reserve(BluCat::core.vk_swapchain->images_count);
-    for(auto i{0}; i < BluCat::core.vk_swapchain->images_count; i++)
+    self->uniform_buffers.reserve(BluCat::INT::core.vk_swapchain->images_count);
+    for(auto i{0}; i < BluCat::INT::core.vk_swapchain->images_count; i++)
       self->uniform_buffers.emplace_back(
-				BluCat::core.vk_device_with_swapchain, sizeof(BluCat::UDOSprite3D));
+				BluCat::INT::core.vk_device_with_swapchain, sizeof(BluCat::GRA::UDOSprite3D));
   }
   catch(const std::exception& e)
   {
@@ -43,7 +43,7 @@ load_uniform_buffers(void *obj)
 void
 unload_uniform_buffers(void *obj)
 {
-  auto self = static_cast<BluCat::Sprite3D*>(obj);
+  auto self = static_cast<BluCat::GRA::Sprite3D*>(obj);
 
   self->uniform_buffers.clear();
 }
@@ -51,7 +51,7 @@ unload_uniform_buffers(void *obj)
 void
 load_descriptor_set_pool(void *obj)
 {
-  auto self = static_cast<BluCat::Sprite3D*>(obj);
+  auto self = static_cast<BluCat::GRA::Sprite3D*>(obj);
 
   std::array<VkDescriptorPoolSize, 1> descriptor_pool_sizes{};
   descriptor_pool_sizes[0].type = VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER;
@@ -75,7 +75,7 @@ load_descriptor_set_pool(void *obj)
 void
 unload_descriptor_set_pool(void *obj)
 {
-  auto self = static_cast<BluCat::Sprite3D*>(obj);
+  auto self = static_cast<BluCat::GRA::Sprite3D*>(obj);
 
   vkDestroyDescriptorPool(
     self->queue_family->device->device, self->descriptor_pool, nullptr);
@@ -83,11 +83,11 @@ unload_descriptor_set_pool(void *obj)
 void
 load_descriptor_sets(void *obj)
 {
-  auto self = static_cast<BluCat::Sprite3D*>(obj);
+  auto self = static_cast<BluCat::GRA::Sprite3D*>(obj);
 
   std::vector<VkDescriptorSetLayout> layouts(
-    BluCat::core.vk_swapchain->images_count,
-    BluCat::core.vk_descriptor_set_layout->model);
+    BluCat::INT::core.vk_swapchain->images_count,
+    BluCat::INT::core.vk_descriptor_set_layout->model);
 
   VkDescriptorSetAllocateInfo alloc_info{};
   alloc_info.sType = VK_STRUCTURE_TYPE_DESCRIPTOR_SET_ALLOCATE_INFO;
@@ -105,14 +105,14 @@ load_descriptor_sets(void *obj)
 void
 load_buffers_to_descriptor_sets(void *obj)
 {
-  auto self = static_cast<BluCat::Sprite3D*>(obj);
+  auto self = static_cast<BluCat::GRA::Sprite3D*>(obj);
 
   for(auto i{0}; i < self->uniform_buffers.size(); i++)
   {
     VkDescriptorBufferInfo buffer_info{};
     buffer_info.buffer = self->uniform_buffers[i].buffer;
     buffer_info.offset = 0;
-    buffer_info.range = sizeof(BluCat::UDOSprite3D);
+    buffer_info.range = sizeof(BluCat::GRA::UDOSprite3D);
 
     VkDescriptorImageInfo image_info{};
     image_info.imageLayout = VK_IMAGE_LAYOUT_SHADER_READ_ONLY_OPTIMAL;
@@ -131,7 +131,7 @@ load_buffers_to_descriptor_sets(void *obj)
     write_descriptors[0].pTexelBufferView = nullptr;
 
     vkUpdateDescriptorSets(
-      BluCat::core.vk_device_with_swapchain->device, write_descriptors.size(),
+      BluCat::INT::core.vk_device_with_swapchain->device, write_descriptors.size(),
       write_descriptors.data(), 0, nullptr);
   }
 }
@@ -145,18 +145,18 @@ static const CommandChain loader{
 
 }
 
-namespace BluCat
+namespace BluCat::GRA
 {
 
 Sprite3D::Sprite3D(
-    std::shared_ptr<BluCat::Sprite> sprite, std::shared_ptr<glm::vec3> position,
+    std::shared_ptr<BluCat::GRA::Sprite> sprite, std::shared_ptr<glm::vec3> position,
     glm::vec2 size):
   sprite{sprite},
   position{position},
   size{size}
 {
   this->queue_family =
-    BluCat::core.vk_device_with_swapchain->get_queue_family_with_graphics();
+    BluCat::INT::core.vk_device_with_swapchain->get_queue_family_with_graphics();
   loader.execute(this);
 }
 
diff --git a/src/blucat/sprite_3d.hpp b/src/blu_cat/gra/sprite_3d.hpp
index 03a13f4..0cd8c04 100644
--- a/src/blucat/sprite_3d.hpp
+++ b/src/blu_cat/gra/sprite_3d.hpp
@@ -14,13 +14,13 @@
  * limitations under the License.
  */
 
-#ifndef CANDY_GEAR_BLUCAT_SPRITE_3D_H
-#define CANDY_GEAR_BLUCAT_SPRITE_3D_H 1
+#ifndef BLU_CAT_GRA_SPRITE_3D_H
+#define BLU_CAT_GRA_SPRITE_3D_H 1
 
 #include "vulkan.hpp"
 #include "sprite.hpp"
 
-namespace BluCat
+namespace BluCat::GRA
 {
 
 struct Sprite3D
@@ -43,4 +43,4 @@ struct Sprite3D
 
 }
 
-#endif /* CANDY_GEAR_BLUCAT_SPRITE_3D_H */
+#endif /* BLU_CAT_GRA_SPRITE_3D_H */
diff --git a/src/blucat/sprite_to_draw.cpp b/src/blu_cat/gra/sprite_to_draw.cpp
index 9013adb..7645d73 100644
--- a/src/blucat/sprite_to_draw.cpp
+++ b/src/blu_cat/gra/sprite_to_draw.cpp
@@ -16,7 +16,7 @@
 
 #include "sprite_to_draw.hpp"
 
-namespace BluCat
+namespace BluCat::GRA
 {
   SpriteToDraw::SpriteToDraw(
     std::shared_ptr<Sprite> sprite, const glm::vec4 &position, float z_index):
diff --git a/src/blucat/sprite_to_draw.hpp b/src/blu_cat/gra/sprite_to_draw.hpp
index c122437..e7a23c4 100644
--- a/src/blucat/sprite_to_draw.hpp
+++ b/src/blu_cat/gra/sprite_to_draw.hpp
@@ -14,15 +14,15 @@
  * limitations under the License.
  */
 
-#ifndef CANDY_GEAR_BLUCAT_SPRITES_TO_DRAW_H
-#define CANDY_GEAR_BLUCAT_SPRITES_TO_DRAW_H 1
+#ifndef BLU_CAT_GRA_SPRITES_TO_DRAW_H
+#define BLU_CAT_GRA_SPRITES_TO_DRAW_H 1
 
 #include <memory>
 
 #include "vulkan.hpp"
 #include "sprite.hpp"
 
-namespace BluCat
+namespace BluCat::GRA
 {
   struct SpriteToDraw
   {
@@ -41,4 +41,4 @@ namespace BluCat
   operator>(const SpriteToDraw &a, const SpriteToDraw &b);
 }
 
-#endif /* CANDY_GEAR_BLUCAT_SPRITES_TO_DRAW_H */
+#endif /* BLU_CAT_GRA_SPRITES_TO_DRAW_H */
diff --git a/src/blucat/static_mesh.cpp b/src/blu_cat/gra/static_mesh.cpp
index a7c1c53..db3a6ee 100644
--- a/src/blucat/static_mesh.cpp
+++ b/src/blu_cat/gra/static_mesh.cpp
@@ -17,8 +17,8 @@
 #include "static_mesh.hpp"
 
 #include "binary_reader.hpp"
-#include "command.hpp"
-#include "core.hpp"
+#include "../com/command.hpp"
+#include "../int/core.hpp"
 #include "static_mesh_vertex.hpp"
 
 namespace
@@ -29,19 +29,19 @@ namespace
 struct MeshBuilder
 {
   std::string mesh_path;
-  BluCat::StaticMesh *mesh;
+  BluCat::GRA::StaticMesh *mesh;
 
-  MeshBuilder(BluCat::StaticMesh *m, std::string mp);
-  MeshBuilder(BluCat::StaticMesh *m, const char* mp);
+  MeshBuilder(BluCat::GRA::StaticMesh *m, std::string mp);
+  MeshBuilder(BluCat::GRA::StaticMesh *m, const char* mp);
 };
 
-MeshBuilder::MeshBuilder(BluCat::StaticMesh *m, std::string mp):
+MeshBuilder::MeshBuilder(BluCat::GRA::StaticMesh *m, std::string mp):
   mesh{m},
   mesh_path{mp}
 {
 }
 
-MeshBuilder::MeshBuilder(BluCat::StaticMesh *m, const char *mp):
+MeshBuilder::MeshBuilder(BluCat::GRA::StaticMesh *m, const char *mp):
   MeshBuilder{m, std::string(mp)}
 {
 }
@@ -54,11 +54,11 @@ load_mesh(void *obj)
   BinaryReader input{self->mesh_path};
 
   self->mesh->queue_family =
-    BluCat::core.vk_device_with_swapchain->get_queue_family_with_graphics();
+    BluCat::INT::core.vk_device_with_swapchain->get_queue_family_with_graphics();
 
   { // Load vertexes.
     auto vertex_count{input.read_ui32()};
-    std::vector<BluCat::StaticMeshVertex> vertexes{vertex_count};
+    std::vector<BluCat::GRA::StaticMeshVertex> vertexes{vertex_count};
 
     for(auto i{0}; i < vertex_count; i++)
     {
@@ -69,9 +69,9 @@ load_mesh(void *obj)
 
     void *vertexes_data{vertexes.data()};
     size_t vertexes_size = sizeof(vertexes[0]) * vertexes.size();
-    self->mesh->source_vertex_buffer = new BluCat::SourceBuffer{
+    self->mesh->source_vertex_buffer = new BluCat::GRA::SourceBuffer{
       self->mesh->queue_family->device, vertexes_data, vertexes_size};
-    self->mesh->vertex_buffer = new BluCat::DestinationBuffer{
+    self->mesh->vertex_buffer = new BluCat::GRA::DestinationBuffer{
       self->mesh->queue_family, self->mesh->source_vertex_buffer,
       VK_BUFFER_USAGE_VERTEX_BUFFER_BIT};
   }
@@ -85,9 +85,9 @@ load_mesh(void *obj)
 
     void *indexes_data{indexes.data()};
     size_t indexes_size{sizeof(indexes[0]) * indexes.size()};
-    BluCat::SourceBuffer source_index_buffer{
+    BluCat::GRA::SourceBuffer source_index_buffer{
       self->mesh->queue_family->device, indexes_data, indexes_size};
-    self->mesh->index_buffer = new BluCat::DestinationBuffer{
+    self->mesh->index_buffer = new BluCat::GRA::DestinationBuffer{
       self->mesh->queue_family, &source_index_buffer,
       VK_BUFFER_USAGE_INDEX_BUFFER_BIT};
   }
@@ -109,7 +109,7 @@ static const CommandChain loader{
 
 }
 
-namespace BluCat
+namespace BluCat::GRA
 {
 
 StaticMesh::StaticMesh(std::string mesh_path)
diff --git a/src/blucat/static_mesh.hpp b/src/blu_cat/gra/static_mesh.hpp
index 04c5e3b..2b059fe 100644
--- a/src/blucat/static_mesh.hpp
+++ b/src/blu_cat/gra/static_mesh.hpp
@@ -14,8 +14,8 @@
  * limitations under the License.
  */
 
-#ifndef CANDY_GEAR_BLUCAT_STATIC_MESH_H
-#define CANDY_GEAR_BLUCAT_STATIC_MESH_H 1
+#ifndef BLU_CAT_GRA_STATIC_MESH_H
+#define BLU_CAT_GRA_STATIC_MESH_H 1
 
 #include <string>
 #include <vector>
@@ -26,7 +26,7 @@
 #include "uniform_buffer.hpp"
 #include "texture.hpp"
 
-namespace BluCat
+namespace BluCat::GRA
 {
 
 struct StaticMesh
@@ -45,4 +45,4 @@ struct StaticMesh
 
 }
 
-#endif /* CANDY_GEAR_BLUCAT_STATIC_MESH_H */
+#endif /* BLU_CAT_GRA_STATIC_MESH_H */
diff --git a/src/blucat/static_mesh_vertex.hpp b/src/blu_cat/gra/static_mesh_vertex.hpp
index 4f7c6d4..510ce40 100644
--- a/src/blucat/static_mesh_vertex.hpp
+++ b/src/blu_cat/gra/static_mesh_vertex.hpp
@@ -14,12 +14,12 @@
  * limitations under the License.
  */
 
-#ifndef CANDY_GEAR_BLUCAT_STATIC_MESH_VERTEX_H
-#define CANDY_GEAR_BLUCAT_STATIC_MESH_VERTEX_H 1
+#ifndef BLU_CAT_GRA_STATIC_MESH_VERTEX_H
+#define BLU_CAT_GRA_STATIC_MESH_VERTEX_H 1
 
 #include "vulkan.hpp"
 
-namespace BluCat
+namespace BluCat::GRA
 {
 
 struct StaticMeshVertex
@@ -31,4 +31,4 @@ struct StaticMeshVertex
 
 }
 
-#endif /* CANDY_GEAR_BLUCAT_STATIC_MESH_VERTEX_H */
+#endif /* BLU_CAT_GRA_STATIC_MESH_VERTEX_H */
diff --git a/src/blucat/static_model.cpp b/src/blu_cat/gra/static_model.cpp
index 60c2536..50dc94d 100644
--- a/src/blucat/static_model.cpp
+++ b/src/blu_cat/gra/static_model.cpp
@@ -16,7 +16,7 @@
 
 #include "static_model.hpp"
 
-#include "core.hpp"
+#include "../int/core.hpp"
 #include "uniform_data_object.hpp"
 
 namespace
@@ -25,14 +25,14 @@ namespace
 void
 load_uniform_buffers(void *obj)
 {
-  auto self = static_cast<BluCat::StaticModel*>(obj);
+  auto self = static_cast<BluCat::GRA::StaticModel*>(obj);
 
   try
   {
-    self->uniform_buffers.reserve(BluCat::core.vk_swapchain->images_count);
-    for(auto i{0}; i < BluCat::core.vk_swapchain->images_count; i++)
+    self->uniform_buffers.reserve(BluCat::INT::core.vk_swapchain->images_count);
+    for(auto i{0}; i < BluCat::INT::core.vk_swapchain->images_count; i++)
       self->uniform_buffers.emplace_back(
-				BluCat::core.vk_device_with_swapchain, sizeof(BluCat::UDOStaticModel));
+				BluCat::INT::core.vk_device_with_swapchain, sizeof(BluCat::GRA::UDOStaticModel));
   }
   catch(const std::exception& e)
   {
@@ -43,7 +43,7 @@ load_uniform_buffers(void *obj)
 void
 unload_uniform_buffers(void *obj)
 {
-  auto self = static_cast<BluCat::StaticModel*>(obj);
+  auto self = static_cast<BluCat::GRA::StaticModel*>(obj);
 
   self->uniform_buffers.clear();
 }
@@ -51,7 +51,7 @@ unload_uniform_buffers(void *obj)
 void
 load_descriptor_set_pool(void *obj)
 {
-  auto self = static_cast<BluCat::StaticModel*>(obj);
+  auto self = static_cast<BluCat::GRA::StaticModel*>(obj);
 
   std::array<VkDescriptorPoolSize, 1> descriptor_pool_sizes{};
   descriptor_pool_sizes[0].type = VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER;
@@ -75,7 +75,7 @@ load_descriptor_set_pool(void *obj)
 void
 unload_descriptor_set_pool(void *obj)
 {
-  auto self = static_cast<BluCat::StaticModel*>(obj);
+  auto self = static_cast<BluCat::GRA::StaticModel*>(obj);
 
   vkDestroyDescriptorPool(
     self->static_mesh->queue_family->device->device, self->descriptor_pool,
@@ -85,11 +85,11 @@ unload_descriptor_set_pool(void *obj)
 void
 load_descriptor_sets(void *obj)
 {
-  auto self = static_cast<BluCat::StaticModel*>(obj);
+  auto self = static_cast<BluCat::GRA::StaticModel*>(obj);
 
   std::vector<VkDescriptorSetLayout> layouts(
-    BluCat::core.vk_swapchain->images_count,
-    BluCat::core.vk_descriptor_set_layout->model);
+    BluCat::INT::core.vk_swapchain->images_count,
+    BluCat::INT::core.vk_descriptor_set_layout->model);
 
   VkDescriptorSetAllocateInfo alloc_info{};
   alloc_info.sType = VK_STRUCTURE_TYPE_DESCRIPTOR_SET_ALLOCATE_INFO;
@@ -107,14 +107,14 @@ load_descriptor_sets(void *obj)
 void
 load_buffers_to_descriptor_sets(void *obj)
 {
-  auto self = static_cast<BluCat::StaticModel*>(obj);
+  auto self = static_cast<BluCat::GRA::StaticModel*>(obj);
 
   for(auto i{0}; i < self->uniform_buffers.size(); i++)
   {
     VkDescriptorBufferInfo buffer_info{};
     buffer_info.buffer = self->uniform_buffers[i].buffer;
     buffer_info.offset = 0;
-    buffer_info.range = sizeof(BluCat::UDOStaticModel);
+    buffer_info.range = sizeof(BluCat::GRA::UDOStaticModel);
 
     std::array<VkWriteDescriptorSet, 1> write_descriptors{};
     write_descriptors[0].sType = VK_STRUCTURE_TYPE_WRITE_DESCRIPTOR_SET;
@@ -128,7 +128,7 @@ load_buffers_to_descriptor_sets(void *obj)
     write_descriptors[0].pTexelBufferView = nullptr;
 
     vkUpdateDescriptorSets(
-      BluCat::core.vk_device_with_swapchain->device, write_descriptors.size(),
+      BluCat::INT::core.vk_device_with_swapchain->device, write_descriptors.size(),
       write_descriptors.data(), 0, nullptr);
   }
 }
@@ -142,7 +142,7 @@ static const CommandChain loader{
 
 }
 
-namespace BluCat
+namespace BluCat::GRA
 {
 
 StaticModel::StaticModel(
diff --git a/src/blucat/static_model.hpp b/src/blu_cat/gra/static_model.hpp
index c300c8f..0d689d0 100644
--- a/src/blucat/static_model.hpp
+++ b/src/blu_cat/gra/static_model.hpp
@@ -14,8 +14,8 @@
  * limitations under the License.
  */
 
-#ifndef CANDY_GEAR_BLUCAT_STATIC_MODEL_H
-#define CANDY_GEAR_BLUCAT_STATIC_MODEL_H 1
+#ifndef BLU_CAT_GRA_STATIC_MODEL_H
+#define BLU_CAT_GRA_STATIC_MODEL_H 1
 
 #include <memory>
 #include <vector>
@@ -23,7 +23,7 @@
 #include "vulkan.hpp"
 #include "static_mesh.hpp"
 
-namespace BluCat
+namespace BluCat::GRA
 {
 
 struct StaticModel
@@ -46,4 +46,4 @@ struct StaticModel
 
 }
 
-#endif /* CANDY_GEAR_BLUCAT_STATIC_MODEL_H */
+#endif /* BLU_CAT_GRA_STATIC_MODEL_H */
diff --git a/src/blucat/swapchain.cpp b/src/blu_cat/gra/swapchain.cpp
index 613cf9b..f57e3c2 100644
--- a/src/blucat/swapchain.cpp
+++ b/src/blu_cat/gra/swapchain.cpp
@@ -16,7 +16,7 @@
 
 #include "swapchain.hpp"
 
-#include "core.hpp"
+#include "../int/core.hpp"
 
 #include <vector>
 
@@ -26,25 +26,25 @@ namespace
 void
 load_swapchain(void *obj)
 {
-  auto self = static_cast<BluCat::Swapchain*>(obj);
+  auto self = static_cast<BluCat::GRA::Swapchain*>(obj);
 
   // Surface formats.
   uint32_t vk_surface_format_count;
   std::vector<VkSurfaceFormatKHR> vk_surface_formats;
   vkGetPhysicalDeviceSurfaceFormatsKHR(
-    BluCat::core.vk_device_with_swapchain->physical_device,
-		BluCat::core.window_surface, &vk_surface_format_count, nullptr);
+    BluCat::INT::core.vk_device_with_swapchain->physical_device,
+		BluCat::INT::core.window_surface, &vk_surface_format_count, nullptr);
   vk_surface_formats.resize(vk_surface_format_count);
   vkGetPhysicalDeviceSurfaceFormatsKHR(
-    BluCat::core.vk_device_with_swapchain->physical_device,
-		BluCat::core.window_surface, &vk_surface_format_count,
+    BluCat::INT::core.vk_device_with_swapchain->physical_device,
+		BluCat::INT::core.window_surface, &vk_surface_format_count,
 		vk_surface_formats.data());
 
   VkSwapchainCreateInfoKHR swapchain_create_info = {};
   swapchain_create_info.sType = VK_STRUCTURE_TYPE_SWAPCHAIN_CREATE_INFO_KHR;
   swapchain_create_info.pNext = nullptr;
   swapchain_create_info.flags = 0;
-  swapchain_create_info.surface = BluCat::core.window_surface;
+  swapchain_create_info.surface = BluCat::INT::core.window_surface;
   swapchain_create_info.minImageCount = 3; // triple buffering.
 
   self->image_format = vk_surface_formats[0].format;
@@ -52,7 +52,7 @@ load_swapchain(void *obj)
   swapchain_create_info.imageColorSpace = vk_surface_formats[0].colorSpace;
 
   swapchain_create_info.imageExtent = {
-    BluCat::core.display_width, BluCat::core.display_height};
+    BluCat::INT::core.display_width, BluCat::INT::core.display_height};
   swapchain_create_info.imageArrayLayers = 1;
   swapchain_create_info.imageUsage = VK_IMAGE_USAGE_COLOR_ATTACHMENT_BIT;
   swapchain_create_info.imageSharingMode = VK_SHARING_MODE_EXCLUSIVE;
@@ -65,33 +65,33 @@ load_swapchain(void *obj)
   swapchain_create_info.oldSwapchain = VK_NULL_HANDLE;
 
   if(vkCreateSwapchainKHR(
-       BluCat::core.vk_device_with_swapchain->device, &swapchain_create_info,
+       BluCat::INT::core.vk_device_with_swapchain->device, &swapchain_create_info,
        nullptr, &self->swapchain) != VK_SUCCESS)
     throw CommandError{"Vulkan failed to create swapchain."};
 
   vkGetSwapchainImagesKHR(
-    BluCat::core.vk_device_with_swapchain->device, self->swapchain,
+    BluCat::INT::core.vk_device_with_swapchain->device, self->swapchain,
     &self->images_count, nullptr);
   self->images = new VkImage[self->images_count];
   vkGetSwapchainImagesKHR(
-    BluCat::core.vk_device_with_swapchain->device, self->swapchain,
+    BluCat::INT::core.vk_device_with_swapchain->device, self->swapchain,
     &self->images_count, self->images);
 }
 
 void
 unload_swapchain(void *obj)
 {
-  auto self = static_cast<BluCat::Swapchain*>(obj);
+  auto self = static_cast<BluCat::GRA::Swapchain*>(obj);
 
   delete[] self->images;
   vkDestroySwapchainKHR(
-    BluCat::core.vk_device_with_swapchain->device, self->swapchain, nullptr);
+    BluCat::INT::core.vk_device_with_swapchain->device, self->swapchain, nullptr);
 }
 
 void
 load_image_view(void *obj)
 {
-  auto self = static_cast<BluCat::Swapchain*>(obj);
+  auto self = static_cast<BluCat::GRA::Swapchain*>(obj);
 
   self->image_views = new VkImageView[self->images_count];
   for(auto i{0}; i < self->images_count; i++)
@@ -112,7 +112,7 @@ load_image_view(void *obj)
     create_info.subresourceRange.layerCount = 1;
 
     if(vkCreateImageView(
-	 BluCat::core.vk_device_with_swapchain->device, &create_info, nullptr,
+	 BluCat::INT::core.vk_device_with_swapchain->device, &create_info, nullptr,
 	 &self->image_views[i]))
       throw CommandError{"Could no create Image View for swapchain."};
   }
@@ -121,18 +121,18 @@ load_image_view(void *obj)
 void
 unload_image_view(void *obj)
 {
-  auto self = static_cast<BluCat::Swapchain*>(obj);
+  auto self = static_cast<BluCat::GRA::Swapchain*>(obj);
 
   for(auto i{0}; i < self->images_count; i++)
     vkDestroyImageView(
-      BluCat::core.vk_device_with_swapchain->device, self->image_views[i],
+      BluCat::INT::core.vk_device_with_swapchain->device, self->image_views[i],
 			nullptr);
 }
 
 void
 load_frame_sync(void *obj)
 {
-  auto self = static_cast<BluCat::Swapchain*>(obj);
+  auto self = static_cast<BluCat::GRA::Swapchain*>(obj);
 
   self->image_available_semaphores.resize(self->max_frames_in_flight);
   self->render_finished_semaphores.resize(self->max_frames_in_flight);
@@ -152,13 +152,13 @@ load_frame_sync(void *obj)
   for(auto i{0}; i < self->max_frames_in_flight; i++)
   {
     if(vkCreateSemaphore(
-	 BluCat::core.vk_device_with_swapchain->device, &semaphore_info,
+	 BluCat::INT::core.vk_device_with_swapchain->device, &semaphore_info,
 	 nullptr, &self->image_available_semaphores[i]) != VK_SUCCESS ||
        vkCreateSemaphore(
-	 BluCat::core.vk_device_with_swapchain->device, &semaphore_info,
+	 BluCat::INT::core.vk_device_with_swapchain->device, &semaphore_info,
 	 nullptr, &self->render_finished_semaphores[i]) != VK_SUCCESS ||
        vkCreateFence(
-				 BluCat::core.vk_device_with_swapchain->device, &fence_info,
+				 BluCat::INT::core.vk_device_with_swapchain->device, &fence_info,
 				 nullptr, &self->in_flight_fences[i]) != VK_SUCCESS)
       throw CommandError{"Failed to create semaphores."};
   }
@@ -167,17 +167,17 @@ load_frame_sync(void *obj)
 void
 unload_frame_sync(void *obj)
 {
-  auto self = static_cast<BluCat::Swapchain*>(obj);
+  auto self = static_cast<BluCat::GRA::Swapchain*>(obj);
 
-  vkDeviceWaitIdle(BluCat::core.vk_device_with_swapchain->device);
+  vkDeviceWaitIdle(BluCat::INT::core.vk_device_with_swapchain->device);
 
   for(auto i{0}; i < self->max_frames_in_flight; i++)
   {
-    vkDestroySemaphore(BluCat::core.vk_device_with_swapchain->device,
+    vkDestroySemaphore(BluCat::INT::core.vk_device_with_swapchain->device,
                        self->render_finished_semaphores[i], nullptr);
-    vkDestroySemaphore(BluCat::core.vk_device_with_swapchain->device,
+    vkDestroySemaphore(BluCat::INT::core.vk_device_with_swapchain->device,
                        self->image_available_semaphores[i], nullptr);
-    vkDestroyFence(BluCat::core.vk_device_with_swapchain->device,
+    vkDestroyFence(BluCat::INT::core.vk_device_with_swapchain->device,
 									 self->in_flight_fences[i], nullptr);
   }
 }
@@ -190,7 +190,7 @@ const CommandChain loader{
 
 }
 
-namespace BluCat
+namespace BluCat::GRA
 {
 
 Swapchain::Swapchain():
diff --git a/src/blucat/swapchain.hpp b/src/blu_cat/gra/swapchain.hpp
index a6f588d..2b52dd6 100644
--- a/src/blucat/swapchain.hpp
+++ b/src/blu_cat/gra/swapchain.hpp
@@ -14,13 +14,13 @@
  * limitations under the License.
  */
 
-#ifndef CANDY_GEAR_BLUCAT_SWAPCHAIN_H
-#define CANDY_GEAR_BLUCAT_SWAPCHAIN_H 1
+#ifndef BLU_CAT_GRA_SWAPCHAIN_H
+#define BLU_CAT_GRA_SWAPCHAIN_H 1
 
-#include "command.hpp"
+#include "../com/command.hpp"
 #include "vulkan.hpp"
 
-namespace BluCat
+namespace BluCat::GRA
 {
 
 struct Swapchain
@@ -44,4 +44,4 @@ struct Swapchain
 
 }
 
-#endif /* CANDY_GEAR_BLUCAT_SWAPCHAIN_H */
+#endif /* BLU_CAT_GRA_SWAPCHAIN_H */
diff --git a/src/blucat/texture.cpp b/src/blu_cat/gra/texture.cpp
index afab950..5abf751 100644
--- a/src/blucat/texture.cpp
+++ b/src/blu_cat/gra/texture.cpp
@@ -16,8 +16,8 @@
 
 #include "texture.hpp"
 
-#include "command.hpp"
-#include "core.hpp"
+#include "../com/command.hpp"
+#include "../int/core.hpp"
 #include "image.hpp"
 #include "qoi.hpp"
 #include "source_buffer.hpp"
@@ -35,8 +35,8 @@ create_vulkan_image(
   vk_extent3d.height = height;
   vk_extent3d.depth = 1;
 
-  BluCat::Image::create(
-    BluCat::core.vk_device_with_swapchain,
+  BluCat::GRA::Image::create(
+    BluCat::INT::core.vk_device_with_swapchain,
     image,
     device_memory,
     VK_FORMAT_R8G8B8A8_UNORM,
@@ -48,25 +48,25 @@ create_vulkan_image(
 
 struct ImageBuilder
 {
-  BluCat::Texture *texture;
+  BluCat::GRA::Texture *texture;
 };
 
 struct ImageTextureBuilder: public ImageBuilder
 {
   std::string texture_path;
 
-  ImageTextureBuilder(BluCat::Texture *t, const std::string &tp);
-  ImageTextureBuilder(BluCat::Texture *t, const char* tp);
+  ImageTextureBuilder(BluCat::GRA::Texture *t, const std::string &tp);
+  ImageTextureBuilder(BluCat::GRA::Texture *t, const char* tp);
 };
 
 ImageTextureBuilder::ImageTextureBuilder(
-	BluCat::Texture *t, const std::string &tp):
+	BluCat::GRA::Texture *t, const std::string &tp):
   texture_path{tp}
 {
   this->texture = t;
 }
 
-ImageTextureBuilder::ImageTextureBuilder(BluCat::Texture *t, const char* tp):
+ImageTextureBuilder::ImageTextureBuilder(BluCat::GRA::Texture *t, const char* tp):
   ImageTextureBuilder{t, std::string(tp)}
 {
 }
@@ -77,7 +77,7 @@ load_image(void *obj)
   auto self = static_cast<ImageTextureBuilder*>(obj);
 
   const int num_channels = 4; // all images are converted to RGBA
-  BluCat::QOI::Image qoi_image(self->texture_path.c_str(), num_channels);
+  BluCat::GRA::QOI::Image qoi_image(self->texture_path.c_str(), num_channels);
   uint8_t *pixels;
 
   { // Load file image from file.
@@ -91,8 +91,8 @@ load_image(void *obj)
   // Load file image into a vulkan buffer.
   size_t image_size{static_cast<size_t>(
       qoi_image.header.width * qoi_image.header.height * num_channels)};
-  BluCat::SourceBuffer source_image_buffer{
-    BluCat::core.vk_device_with_swapchain, pixels, image_size};
+  BluCat::GRA::SourceBuffer source_image_buffer{
+    BluCat::INT::core.vk_device_with_swapchain, pixels, image_size};
 
   { // Create vulkan image.
     try
@@ -104,7 +104,7 @@ load_image(void *obj)
         self->texture->height,
         self->texture->mip_levels);
     }
-    catch(BluCat::Image::Error error)
+    catch(BluCat::GRA::Image::Error error)
     {
       throw CommandError{error.what()};
     }
@@ -114,11 +114,11 @@ load_image(void *obj)
   {
     auto queue_family = self->texture->queue_family;
     auto queue{queue_family->get_queue()};
-    BluCat::CommandPool command_pool{queue_family, 1};
+    BluCat::GRA::CommandPool command_pool{queue_family, 1};
     VkCommandBuffer vk_command_buffer{command_pool.command_buffers[0]};
 
     queue.submit_one_time_command(vk_command_buffer, [&](){
-      BluCat::Image::move_image_state(
+      BluCat::GRA::Image::move_image_state(
 	vk_command_buffer, self->texture->image, VK_FORMAT_R8G8B8A8_UNORM,
 	0, VK_ACCESS_TRANSFER_WRITE_BIT,
 	VK_IMAGE_LAYOUT_UNDEFINED, VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL,
@@ -140,7 +140,7 @@ load_image(void *obj)
 	vk_command_buffer, source_image_buffer.buffer, self->texture->image,
 	VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL, 1, &image_copy);
 
-      BluCat::Image::move_image_state(
+      BluCat::GRA::Image::move_image_state(
 	vk_command_buffer, self->texture->image, VK_FORMAT_R8G8B8A8_UNORM,
 	VK_ACCESS_TRANSFER_WRITE_BIT, VK_ACCESS_SHADER_READ_BIT,
 	VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL,
@@ -157,10 +157,10 @@ unload_image(void *obj)
   auto self = static_cast<ImageBuilder*>(obj);
 
   vkDestroyImage(
-    BluCat::core.vk_device_with_swapchain->device, self->texture->image,
+    BluCat::INT::core.vk_device_with_swapchain->device, self->texture->image,
 		nullptr);
   vkFreeMemory(
-    BluCat::core.vk_device_with_swapchain->device,
+    BluCat::INT::core.vk_device_with_swapchain->device,
 		self->texture->device_memory, nullptr);
 }
 
@@ -190,7 +190,7 @@ load_sampler(void *obj)
   sampler_info.unnormalizedCoordinates = VK_FALSE;
 
   if(vkCreateSampler(
-       BluCat::core.vk_device_with_swapchain->device, &sampler_info, nullptr,
+       BluCat::INT::core.vk_device_with_swapchain->device, &sampler_info, nullptr,
        &self->texture->sampler) != VK_SUCCESS)
     throw CommandError{"Failed to create texture sampler."};
 }
@@ -201,7 +201,7 @@ unload_sampler(void *obj)
   auto self = static_cast<ImageBuilder*>(obj);
 
   vkDestroySampler(
-    BluCat::core.vk_device_with_swapchain->device, self->texture->sampler,
+    BluCat::INT::core.vk_device_with_swapchain->device, self->texture->sampler,
 		nullptr);
 }
 
@@ -212,12 +212,12 @@ load_view(void *obj)
 
   try
   {
-    BluCat::Image::create_view(
-      BluCat::core.vk_device_with_swapchain, &self->texture->view,
+    BluCat::GRA::Image::create_view(
+      BluCat::INT::core.vk_device_with_swapchain, &self->texture->view,
       self->texture->image,
       VK_FORMAT_R8G8B8A8_UNORM, VK_IMAGE_ASPECT_COLOR_BIT);
   }
-  catch(BluCat::Image::Error error)
+  catch(BluCat::GRA::Image::Error error)
   {
     throw CommandError{error.what()};
   }
@@ -229,7 +229,7 @@ unload_view(void *obj)
   auto self = static_cast<ImageBuilder*>(obj);
 
   vkDestroyImageView(
-    BluCat::core.vk_device_with_swapchain->device, self->texture->view,
+    BluCat::INT::core.vk_device_with_swapchain->device, self->texture->view,
 		nullptr);
 }
 
@@ -242,9 +242,9 @@ const CommandChain image_loader{
 struct CharacterToDraw
 {
   int pos_x;
-  std::shared_ptr<BluCat::Character> character;
+  std::shared_ptr<BluCat::GRA::Character> character;
 
-  CharacterToDraw(int x, std::shared_ptr<BluCat::Character> character):
+  CharacterToDraw(int x, std::shared_ptr<BluCat::GRA::Character> character):
     pos_x{x},
     character{character}
     {};
@@ -252,12 +252,12 @@ struct CharacterToDraw
 
 struct TextTextureBuilder: public ImageBuilder
 {
-  BluCat::Font *font;
+  BluCat::GRA::Font *font;
   const char* str;
   uint32_t max_bearing_y;
   std::vector<CharacterToDraw> chars_to_draw;
 
-  TextTextureBuilder(BluCat::Texture *texture, BluCat::Font *font, const char* str):
+  TextTextureBuilder(BluCat::GRA::Texture *texture, BluCat::GRA::Font *font, const char* str):
     font{font},
     str{str}
     {
@@ -271,7 +271,7 @@ load_text_proportions(void *obj)
   auto self = static_cast<TextTextureBuilder*>(obj);
 
   uint32_t texture_width{0}, texture_descender{0};
-  auto unicode_text{BluCat::Character::str_to_unicode(self->str)};
+  auto unicode_text{BluCat::GRA::Character::str_to_unicode(self->str)};
 
   auto first_image{self->font->character(unicode_text[0])};
   if(first_image->bearing_x < 0) texture_width = - first_image->bearing_x;
@@ -281,7 +281,7 @@ load_text_proportions(void *obj)
 
   // FIXME: I need to test several different fonts to find all bugs in this
   // code.
-  std::shared_ptr<BluCat::Character> char_image{};
+  std::shared_ptr<BluCat::GRA::Character> char_image{};
   { // Calculate image size
     int max_height;
     for(auto char_code : unicode_text)
@@ -334,8 +334,8 @@ load_text_image(void *obj)
       pixels[image_coord + 3] = 0; // Alpha
     }
   }
-  BluCat::SourceBuffer source_image_buffer{
-    BluCat::core.vk_device_with_swapchain, pixels.data(), image_size};
+  BluCat::GRA::SourceBuffer source_image_buffer{
+    BluCat::INT::core.vk_device_with_swapchain, pixels.data(), image_size};
 
   { // Create vulkan image.
     try
@@ -347,7 +347,7 @@ load_text_image(void *obj)
         self->texture->height,
         self->texture->mip_levels);
     }
-    catch(BluCat::Image::Error error)
+    catch(BluCat::GRA::Image::Error error)
     {
       throw CommandError{error.what()};
     }
@@ -355,14 +355,14 @@ load_text_image(void *obj)
 
   { // Render text
     auto queue_family{
-      BluCat::core.vk_device_with_swapchain->
+      BluCat::INT::core.vk_device_with_swapchain->
 			get_queue_family_with_presentation()};
     auto queue{queue_family->get_queue()};
-    BluCat::CommandPool command_pool{queue_family, 1};
+    BluCat::GRA::CommandPool command_pool{queue_family, 1};
     VkCommandBuffer vk_command_buffer{command_pool.command_buffers[0]};
 
     queue.submit_one_time_command(vk_command_buffer, [&](){
-      BluCat::Image::move_image_state(
+      BluCat::GRA::Image::move_image_state(
 	vk_command_buffer, self->texture->image, VK_FORMAT_R8G8B8A8_UNORM,
 	0, VK_ACCESS_TRANSFER_WRITE_BIT,
 	VK_IMAGE_LAYOUT_UNDEFINED, VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL,
@@ -415,7 +415,7 @@ load_text_image(void *obj)
           1, &image_copy);
       }
 
-      BluCat::Image::move_image_state(
+      BluCat::GRA::Image::move_image_state(
 	vk_command_buffer, self->texture->image, VK_FORMAT_R8G8B8A8_UNORM,
 	VK_ACCESS_TRANSFER_WRITE_BIT, VK_ACCESS_SHADER_READ_BIT,
 	VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL,
@@ -436,18 +436,18 @@ const CommandChain text_loader{
 void
 load_descriptor_set_pool(void *obj)
 {
-  auto self = static_cast<BluCat::Texture*>(obj);
+  auto self = static_cast<BluCat::GRA::Texture*>(obj);
 
   std::array<VkDescriptorPoolSize, 1> descriptor_pool_sizes{};
   descriptor_pool_sizes[0].type = VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER;
   descriptor_pool_sizes[0].descriptorCount =
-    BluCat::core.vk_swapchain->images_count;
+    BluCat::INT::core.vk_swapchain->images_count;
 
   VkDescriptorPoolCreateInfo pool_info{};
   pool_info.sType = VK_STRUCTURE_TYPE_DESCRIPTOR_POOL_CREATE_INFO;
   pool_info.pNext = nullptr;
   pool_info.flags = 0;
-  pool_info.maxSets = BluCat::core.vk_swapchain->images_count;
+  pool_info.maxSets = BluCat::INT::core.vk_swapchain->images_count;
   pool_info.poolSizeCount = descriptor_pool_sizes.size();
   pool_info.pPoolSizes = descriptor_pool_sizes.data();
 
@@ -460,7 +460,7 @@ load_descriptor_set_pool(void *obj)
 void
 unload_descriptor_set_pool(void *obj)
 {
-  auto self = static_cast<BluCat::Texture*>(obj);
+  auto self = static_cast<BluCat::GRA::Texture*>(obj);
 
   vkDestroyDescriptorPool(
     self->queue_family->device->device, self->descriptor_pool, nullptr);
@@ -469,11 +469,11 @@ unload_descriptor_set_pool(void *obj)
 void
 load_descriptor_sets(void *obj)
 {
-  auto self = static_cast<BluCat::Texture*>(obj);
+  auto self = static_cast<BluCat::GRA::Texture*>(obj);
 
   std::vector<VkDescriptorSetLayout> layouts(
-    BluCat::core.vk_swapchain->images_count,
-    BluCat::core.vk_descriptor_set_layout->texture);
+    BluCat::INT::core.vk_swapchain->images_count,
+    BluCat::INT::core.vk_descriptor_set_layout->texture);
 
   VkDescriptorSetAllocateInfo alloc_info{};
   alloc_info.sType = VK_STRUCTURE_TYPE_DESCRIPTOR_SET_ALLOCATE_INFO;
@@ -491,9 +491,9 @@ load_descriptor_sets(void *obj)
 void
 load_data_to_descriptor_sets(void *obj)
 {
-  auto self = static_cast<BluCat::Texture*>(obj);
+  auto self = static_cast<BluCat::GRA::Texture*>(obj);
 
-  for(auto i{0}; i < BluCat::core.vk_swapchain->images_count; i++)
+  for(auto i{0}; i < BluCat::INT::core.vk_swapchain->images_count; i++)
   {
     VkDescriptorImageInfo image_info{};
     image_info.imageLayout = VK_IMAGE_LAYOUT_SHADER_READ_ONLY_OPTIMAL;
@@ -513,7 +513,7 @@ load_data_to_descriptor_sets(void *obj)
     write_descriptors[0].pTexelBufferView = nullptr;
 
     vkUpdateDescriptorSets(
-      BluCat::core.vk_device_with_swapchain->device, write_descriptors.size(),
+      BluCat::INT::core.vk_device_with_swapchain->device, write_descriptors.size(),
       write_descriptors.data(), 0, nullptr);
   }
 }
@@ -526,13 +526,13 @@ const CommandChain descriptor_loader{
 
 }
 
-namespace BluCat
+namespace BluCat::GRA
 {
 
 Texture::Texture(Font *font, const char* str)
 {
   this->queue_family =
-    BluCat::core.vk_device_with_swapchain->
+    BluCat::INT::core.vk_device_with_swapchain->
 		get_queue_family_with_presentation();
 
   TextTextureBuilder text_builder(this, font, str);
@@ -543,7 +543,7 @@ Texture::Texture(Font *font, const char* str)
 Texture::Texture(const std::string &texture_path)
 {
   this->queue_family =
-    BluCat::core.vk_device_with_swapchain->
+    BluCat::INT::core.vk_device_with_swapchain->
 		get_queue_family_with_presentation();
 
   ImageTextureBuilder texture_builder(this, texture_path);
diff --git a/src/blucat/texture.hpp b/src/blu_cat/gra/texture.hpp
index 4bf0350..c3da8cf 100644
--- a/src/blucat/texture.hpp
+++ b/src/blu_cat/gra/texture.hpp
@@ -14,8 +14,8 @@
  * limitations under the License.
  */
 
-#ifndef CANDY_GEAR_BLUCAT_TEXTURE_H
-#define CANDY_GEAR_BLUCAT_TEXTURE_H 1
+#ifndef BLU_CAT_GRA_TEXTURE_H
+#define BLU_CAT_GRA_TEXTURE_H 1
 
 #include <string>
 
@@ -23,7 +23,7 @@
 #include "font.hpp"
 #include "queue_family.hpp"
 
-namespace BluCat
+namespace BluCat::GRA
 {
 
 struct Texture
@@ -48,4 +48,4 @@ struct Texture
 
 }
 
-#endif /* CANDY_GEAR_TEXTURE_H */
+#endif /* BLU_CAT_GRA_TEXTURE_H */
diff --git a/src/blucat/uniform_buffer.cpp b/src/blu_cat/gra/uniform_buffer.cpp
index 4b6194a..b176365 100644
--- a/src/blucat/uniform_buffer.cpp
+++ b/src/blu_cat/gra/uniform_buffer.cpp
@@ -19,7 +19,7 @@
 #include <cstring>
 #include <stdexcept>
 
-namespace BluCat
+namespace BluCat::GRA
 {
 
 UniformBuffer::UniformBuffer(Device *device, VkDeviceSize data_size)
diff --git a/src/blucat/uniform_buffer.hpp b/src/blu_cat/gra/uniform_buffer.hpp
index 1dd7788..f37e100 100644
--- a/src/blucat/uniform_buffer.hpp
+++ b/src/blu_cat/gra/uniform_buffer.hpp
@@ -14,8 +14,8 @@
  * limitations under the License.
  */
 
-#ifndef CANDY_GEAR_BLUCAT_UNIFORM_BUFFER_H
-#define CANDY_GEAR_BLUCAT_UNIFORM_BUFFER_H 1
+#ifndef BLU_CAT_GRA_UNIFORM_BUFFER_H
+#define BLU_CAT_GRA_UNIFORM_BUFFER_H 1
 
 #include <memory>
 
@@ -23,7 +23,7 @@
 
 #include "base_buffer.hpp"
 
-namespace BluCat
+namespace BluCat::GRA
 {
 
 // FIXME: this class need to delete or create custom copy constructors!
@@ -46,4 +46,4 @@ public:
 
 }
 
-#endif /* CANDY_GEAR_BLUCAT_UNIFORM_BUFFER_H */
+#endif /* BLU_CAT_GRA_UNIFORM_BUFFER_H */
diff --git a/src/blucat/uniform_data_object.hpp b/src/blu_cat/gra/uniform_data_object.hpp
index 0549e4e..68a3fbe 100644
--- a/src/blucat/uniform_data_object.hpp
+++ b/src/blu_cat/gra/uniform_data_object.hpp
@@ -14,13 +14,13 @@
  * limitations under the License.
  */
 
-#ifndef CANDY_GEAR_BLUCAT_UNIFORM_DATA_OBJECT_H
-#define CANDY_GEAR_BLUCAT_UNIFORM_DATA_OBJECT_H 1
+#ifndef BLU_CAT_GRA_UNIFORM_DATA_OBJECT_H
+#define BLU_CAT_GRA_UNIFORM_DATA_OBJECT_H 1
 
 #include "vulkan.hpp"
 #include "skeletal_mesh_vertex.hpp"
 
-namespace BluCat
+namespace BluCat::GRA
 {
 
 // UDO = "uniform data object"
@@ -77,4 +77,4 @@ struct UDOSprite3D
 
 }
 
-#endif /* CANDY_GEAR_BLUCAT_UNIFORM_DATA_OBJECT_H */
+#endif /* BLU_CAT_GRA_UNIFORM_DATA_OBJECT_H */
diff --git a/src/blucat/view_2d.cpp b/src/blu_cat/gra/view_2d.cpp
index de764ce..948b145 100644
--- a/src/blucat/view_2d.cpp
+++ b/src/blu_cat/gra/view_2d.cpp
@@ -18,7 +18,7 @@
 
 #include <array>
 
-#include "core.hpp"
+#include "../int/core.hpp"
 #include "uniform_data_object.hpp"
 
 namespace
@@ -27,14 +27,14 @@ namespace
 void
 load_2d_uniform_buffer(void *obj)
 {
-  auto self = static_cast<BluCat::View2D*>(obj);
+  auto self = static_cast<BluCat::GRA::View2D*>(obj);
 
   try
   {
-    self->ub_2d.reserve(BluCat::core.vk_swapchain->images_count);
-    for(auto i{0}; i < BluCat::core.vk_swapchain->images_count; i++)
+    self->ub_2d.reserve(BluCat::INT::core.vk_swapchain->images_count);
+    for(auto i{0}; i < BluCat::INT::core.vk_swapchain->images_count; i++)
       self->ub_2d.emplace_back(
-				BluCat::core.vk_device_with_swapchain, sizeof(BluCat::UDOView2D));
+				BluCat::INT::core.vk_device_with_swapchain, sizeof(BluCat::GRA::UDOView2D));
   }
   catch(const std::exception& e)
   {
@@ -45,7 +45,7 @@ load_2d_uniform_buffer(void *obj)
 void
 unload_2d_uniform_buffer(void *obj)
 {
-  auto self = static_cast<BluCat::View2D*>(obj);
+  auto self = static_cast<BluCat::GRA::View2D*>(obj);
 
   self->ub_2d.clear();
 }
@@ -53,11 +53,11 @@ unload_2d_uniform_buffer(void *obj)
 void
 load_descriptor_sets_2d(void *obj)
 {
-  auto self = static_cast<BluCat::View2D*>(obj);
+  auto self = static_cast<BluCat::GRA::View2D*>(obj);
 
   std::vector<VkDescriptorSetLayout> layouts(
-    BluCat::core.vk_swapchain->images_count,
-    BluCat::core.vk_descriptor_set_layout->view);
+    BluCat::INT::core.vk_swapchain->images_count,
+    BluCat::INT::core.vk_descriptor_set_layout->view);
 
   VkDescriptorSetAllocateInfo alloc_info{};
   alloc_info.sType = VK_STRUCTURE_TYPE_DESCRIPTOR_SET_ALLOCATE_INFO;
@@ -67,7 +67,7 @@ load_descriptor_sets_2d(void *obj)
 
   self->descriptor_sets_2d.resize(layouts.size());
   if(vkAllocateDescriptorSets(
-       BluCat::core.vk_device_with_swapchain->device, &alloc_info,
+       BluCat::INT::core.vk_device_with_swapchain->device, &alloc_info,
        self->descriptor_sets_2d.data()) != VK_SUCCESS)
     throw CommandError{"Failed to create Vulkan descriptor sets for view."};
 }
@@ -75,14 +75,14 @@ load_descriptor_sets_2d(void *obj)
 void
 load_resources_to_descriptor_sets_2d(void *obj)
 {
-  auto self = static_cast<BluCat::View2D*>(obj);
+  auto self = static_cast<BluCat::GRA::View2D*>(obj);
 
   for(auto i{0}; i < self->ub_2d.size(); i++)
   {
     VkDescriptorBufferInfo view_2d_info{};
     view_2d_info.buffer = self->ub_2d[i].buffer;
     view_2d_info.offset = 0;
-    view_2d_info.range = sizeof(BluCat::UDOView2D);
+    view_2d_info.range = sizeof(BluCat::GRA::UDOView2D);
 
     std::array<VkWriteDescriptorSet, 1> write_descriptors{};
     write_descriptors[0].sType = VK_STRUCTURE_TYPE_WRITE_DESCRIPTOR_SET;
@@ -96,10 +96,10 @@ load_resources_to_descriptor_sets_2d(void *obj)
     write_descriptors[0].pTexelBufferView = nullptr;
 
     vkUpdateDescriptorSets(
-      BluCat::core.vk_device_with_swapchain->device, write_descriptors.size(),
+      BluCat::INT::core.vk_device_with_swapchain->device, write_descriptors.size(),
       write_descriptors.data(), 0, nullptr);
 
-    BluCat::UDOView2D ubo_view_2d;
+    BluCat::GRA::UDOView2D ubo_view_2d;
     ubo_view_2d.proj = glm::ortho(
       0.0f, self->projection_width,
       0.0f, self->projection_height,
@@ -110,7 +110,7 @@ load_resources_to_descriptor_sets_2d(void *obj)
 
 }
 
-namespace BluCat
+namespace BluCat::GRA
 {
 
 const CommandChain View2D::loader{
@@ -128,8 +128,8 @@ View2D::View2D(
   projection_height{projection_height},
   region{region},
   descriptor_pool{VK_NULL_HANDLE},
-  rectangles_to_draw{BluCat::core.vk_swapchain->images_count},
-  sprites_to_draw{BluCat::core.vk_swapchain->images_count}
+  rectangles_to_draw{BluCat::INT::core.vk_swapchain->images_count},
+  sprites_to_draw{BluCat::INT::core.vk_swapchain->images_count}
 {
   loader.execute(this);
 }
diff --git a/src/blucat/view_2d.hpp b/src/blu_cat/gra/view_2d.hpp
index b798f19..84b9f09 100644
--- a/src/blucat/view_2d.hpp
+++ b/src/blu_cat/gra/view_2d.hpp
@@ -14,8 +14,8 @@
  * limitations under the License.
  */
 
-#ifndef CANDY_GEAR_BLUCAT_VIEW_2D_H
-#define CANDY_GEAR_BLUCAT_VIEW_2D_H 1
+#ifndef BLU_CAT_GRA_VIEW_2D_H
+#define BLU_CAT_GRA_VIEW_2D_H 1
 
 #include <memory>
 #include <unordered_map>
@@ -25,7 +25,7 @@
 #include "sprite_to_draw.hpp"
 #include "rectangle.hpp"
 
-namespace BluCat
+namespace BluCat::GRA
 {
 
 struct View2D
@@ -57,4 +57,4 @@ protected:
 
 }
 
-#endif /* CANDY_GEAR_BLUCAT_VIEW_2D_H */
+#endif /* BLU_CAT_GRA_VIEW_2D_H */
diff --git a/src/blucat/view_3d.cpp b/src/blu_cat/gra/view_3d.cpp
index be9970c..dc310e3 100644
--- a/src/blucat/view_3d.cpp
+++ b/src/blu_cat/gra/view_3d.cpp
@@ -18,7 +18,7 @@
 
 #include <array>
 
-#include "core.hpp"
+#include "../int/core.hpp"
 #include "uniform_data_object.hpp"
 
 namespace
@@ -27,14 +27,14 @@ namespace
 void
 load_3d_uniform_buffer(void *obj)
 {
-  auto self = static_cast<BluCat::View3D*>(obj);
+  auto self = static_cast<BluCat::GRA::View3D*>(obj);
 
   try
   {
-    self->ub_3d.reserve(BluCat::core.vk_swapchain->images_count);
-    for(auto i{0}; i < BluCat::core.vk_swapchain->images_count; i++)
+    self->ub_3d.reserve(BluCat::INT::core.vk_swapchain->images_count);
+    for(auto i{0}; i < BluCat::INT::core.vk_swapchain->images_count; i++)
       self->ub_3d.emplace_back(
-	BluCat::core.vk_device_with_swapchain, sizeof(BluCat::UDOView3D));
+	BluCat::INT::core.vk_device_with_swapchain, sizeof(BluCat::GRA::UDOView3D));
   }
   catch(const std::exception& e)
   {
@@ -45,7 +45,7 @@ load_3d_uniform_buffer(void *obj)
 void
 unload_3d_uniform_buffer(void *obj)
 {
-  auto self = static_cast<BluCat::View3D*>(obj);
+  auto self = static_cast<BluCat::GRA::View3D*>(obj);
 
   self->ub_3d.clear();
 }
@@ -53,11 +53,11 @@ unload_3d_uniform_buffer(void *obj)
 void
 load_descriptor_sets_3d(void *obj)
 {
-  auto self = static_cast<BluCat::View3D*>(obj);
+  auto self = static_cast<BluCat::GRA::View3D*>(obj);
 
   std::vector<VkDescriptorSetLayout> layouts(
-    BluCat::core.vk_swapchain->images_count,
-    BluCat::core.vk_descriptor_set_layout->view);
+    BluCat::INT::core.vk_swapchain->images_count,
+    BluCat::INT::core.vk_descriptor_set_layout->view);
 
   VkDescriptorSetAllocateInfo alloc_info{};
   alloc_info.sType = VK_STRUCTURE_TYPE_DESCRIPTOR_SET_ALLOCATE_INFO;
@@ -67,7 +67,7 @@ load_descriptor_sets_3d(void *obj)
 
   self->descriptor_sets_3d.resize(layouts.size());
   if(vkAllocateDescriptorSets(
-       BluCat::core.vk_device_with_swapchain->device, &alloc_info,
+       BluCat::INT::core.vk_device_with_swapchain->device, &alloc_info,
        self->descriptor_sets_3d.data()) != VK_SUCCESS)
     throw CommandError{"Failed to create Vulkan descriptor sets for view."};
 }
@@ -75,14 +75,14 @@ load_descriptor_sets_3d(void *obj)
 void
 load_resources_to_descriptor_sets_3d(void *obj)
 {
-  auto self = static_cast<BluCat::View3D*>(obj);
+  auto self = static_cast<BluCat::GRA::View3D*>(obj);
 
   for(auto i{0}; i < self->ub_3d.size(); i++)
   {
     VkDescriptorBufferInfo view_3d_info{};
     view_3d_info.buffer = self->ub_3d[i].buffer;
     view_3d_info.offset = 0;
-    view_3d_info.range = sizeof(BluCat::UDOView3D);
+    view_3d_info.range = sizeof(BluCat::GRA::UDOView3D);
 
     std::array<VkWriteDescriptorSet, 1> write_descriptors{};
     write_descriptors[0].sType = VK_STRUCTURE_TYPE_WRITE_DESCRIPTOR_SET;
@@ -96,7 +96,7 @@ load_resources_to_descriptor_sets_3d(void *obj)
     write_descriptors[0].pTexelBufferView = nullptr;
 
     vkUpdateDescriptorSets(
-      BluCat::core.vk_device_with_swapchain->device, write_descriptors.size(),
+      BluCat::INT::core.vk_device_with_swapchain->device, write_descriptors.size(),
       write_descriptors.data(), 0, nullptr);
   }
 }
@@ -112,7 +112,7 @@ const CommandChain descriptor_sets_loader{
 
 }
 
-namespace BluCat
+namespace BluCat::GRA
 {
 
 View3D::View3D(
@@ -135,7 +135,7 @@ View3D::load_descriptor_sets(VkDescriptorPool descriptor_pool)
 {
   if(this->descriptor_pool != VK_NULL_HANDLE) return;
 
-  auto parent = dynamic_cast<BluCat::View2D*>(this);
+  auto parent = dynamic_cast<BluCat::GRA::View2D*>(this);
   this->descriptor_pool = descriptor_pool;
   View2D::descriptor_sets_loader.execute(parent);
   ::descriptor_sets_loader.execute(this);
@@ -146,7 +146,7 @@ View3D::unload_descriptor_sets()
 {
   if(this->descriptor_pool == VK_NULL_HANDLE) return;
 
-  auto parent = dynamic_cast<BluCat::View2D*>(this);
+  auto parent = dynamic_cast<BluCat::GRA::View2D*>(this);
   this->descriptor_pool = VK_NULL_HANDLE;
   ::descriptor_sets_loader.revert(this);
   View2D::descriptor_sets_loader.revert(parent);
diff --git a/src/blucat/view_3d.hpp b/src/blu_cat/gra/view_3d.hpp
index 05cae6b..f09c70f 100644
--- a/src/blucat/view_3d.hpp
+++ b/src/blu_cat/gra/view_3d.hpp
@@ -14,12 +14,12 @@
  * limitations under the License.
  */
 
-#ifndef CANDY_GEAR_BLUCAT_VIEW_3D_H
-#define CANDY_GEAR_BLUCAT_VIEW_3D_H 1
+#ifndef BLU_CAT_GRA_VIEW_3D_H
+#define BLU_CAT_GRA_VIEW_3D_H 1
 
 #include "view_2d.hpp"
 
-namespace BluCat
+namespace BluCat::GRA
 {
 
 struct View3D: public View2D
@@ -45,4 +45,4 @@ struct View3D: public View2D
 
 }
 
-#endif /* CANDY_GEAR_BLUCAT_VIEW_3D_H */
+#endif /* BLU_CAT_GRA_VIEW_3D_H */
diff --git a/src/blucat/vulkan.hpp b/src/blu_cat/gra/vulkan.hpp
index 24c35f5..fcf6628 100644
--- a/src/blucat/vulkan.hpp
+++ b/src/blu_cat/gra/vulkan.hpp
@@ -14,8 +14,8 @@
  * limitations under the License.
  */
 
-#ifndef BLU_CAT_VULKAN_H
-#define BLU_CAT_VULKAN_H 1
+#ifndef BLU_CAT_GRA_VULKAN_H
+#define BLU_CAT_GRA_VULKAN_H 1
 
 // GLM uses some definitions to control their behavior, so you should not
 // include it directly. Instead, use this header.
@@ -31,4 +31,4 @@
 
 #include <vulkan/vulkan.h>
 
-#endif /* BLU_CAT_VULKAN_H */
+#endif /* BLU_CAT_GRA_VULKAN_H */
diff --git a/src/blucat/core.cpp b/src/blu_cat/int/core.cpp
index 8478f86..eafdab7 100644
--- a/src/blucat/core.cpp
+++ b/src/blu_cat/int/core.cpp
@@ -47,7 +47,7 @@ vk_debug_callback(
 	}
 
 	// Log message.
-	BluCat::core.log.message(log_level, callback_data->pMessage);
+	BluCat::INT::core.log.message(log_level, callback_data->pMessage);
 
 	return VK_FALSE;
 }
@@ -58,15 +58,15 @@ load_threads(void *obj)
 {
 	auto num_threads{std::thread::hardware_concurrency() - 1};
 	for(auto i{0}; i < num_threads; i++)
-		BluCat::core.threads.emplace_back(
-			BluCat::core.workers.emplace_back(&BluCat::core.job_queue));
+		BluCat::INT::core.threads.emplace_back(
+			BluCat::INT::core.workers.emplace_back(&BluCat::INT::core.job_queue));
 }
 
 void
 unload_threads(void *obj)
 {
-	BluCat::core.job_queue.stop();
-	for(auto &t: BluCat::core.threads) t.join();
+	BluCat::INT::core.job_queue.stop();
+	for(auto &t: BluCat::INT::core.threads) t.join();
 }
 
 void
@@ -74,23 +74,23 @@ load_fps(void *obj)
 {
   using namespace std::chrono;
 
-	BluCat::core.max_frame_duration =
-		duration<long long, std::milli>(1000 / BluCat::core.fps);
+	BluCat::INT::core.max_frame_duration =
+		duration<long long, std::milli>(1000 / BluCat::INT::core.fps);
 	// FIXME: actually calculates the real delta time.
-	BluCat::core.delta_time = 1.0f / BluCat::core.fps;
+	BluCat::INT::core.delta_time = 1.0f / BluCat::INT::core.fps;
 }
 
 void
 load_font_library(void *obj)
 {
-	FT_Error error{FT_Init_FreeType(&BluCat::core.font_library)};
+	FT_Error error{FT_Init_FreeType(&BluCat::INT::core.font_library)};
 	if(error) throw CommandError{"Failed to open the FreeType library."};
 }
 
 void
 unload_font_library(void *obj)
 {
-	FT_Done_FreeType(BluCat::core.font_library);
+	FT_Done_FreeType(BluCat::INT::core.font_library);
 }
 
 #ifdef DEBUG
@@ -119,11 +119,11 @@ load_vk_debug_callback(void *obj)
   create_info.flags = 0;
 
   debug_messenger = (PFN_vkCreateDebugUtilsMessengerEXT)
-    vkGetInstanceProcAddr(BluCat::core.vk_instance,
+    vkGetInstanceProcAddr(BluCat::INT::core.vk_instance,
 			  "vkCreateDebugUtilsMessengerEXT");
 
-  if(debug_messenger(BluCat::core.vk_instance, &create_info, nullptr,
-		     &BluCat::core.vk_callback) != VK_SUCCESS)
+  if(debug_messenger(BluCat::INT::core.vk_instance, &create_info, nullptr,
+		     &BluCat::INT::core.vk_callback) != VK_SUCCESS)
     CommandError{"Failed to setup debug callback for Vulkan."};
 }
 
@@ -133,10 +133,10 @@ unload_vk_debug_callback(void *obj)
   PFN_vkDestroyDebugUtilsMessengerEXT debug_messenger;
 
   debug_messenger = (PFN_vkDestroyDebugUtilsMessengerEXT)
-    vkGetInstanceProcAddr(BluCat::core.vk_instance,
+    vkGetInstanceProcAddr(BluCat::INT::core.vk_instance,
 			  "vkDestroyDebugUtilsMessengerEXT");
 
-  debug_messenger(BluCat::core.vk_instance, BluCat::core.vk_callback, nullptr);
+  debug_messenger(BluCat::INT::core.vk_instance, BluCat::INT::core.vk_callback, nullptr);
 }
 #endif
 
@@ -149,42 +149,42 @@ load_devices(void *obj)
   // Enumerate physical devices
   {
     vkEnumeratePhysicalDevices(
-			BluCat::core.vk_instance, &devices_count, nullptr);
+			BluCat::INT::core.vk_instance, &devices_count, nullptr);
     if(devices_count < 1)
       CommandError{"Failed to find GPUs with Vulkan support."};
     vk_physical_devices.resize(devices_count);
     vkEnumeratePhysicalDevices(
-      BluCat::core.vk_instance, &devices_count, vk_physical_devices.data());
+      BluCat::INT::core.vk_instance, &devices_count, vk_physical_devices.data());
   }
 
 #ifdef DEBUG
-  BluCat::core.log.message(Log::Level::Trace, "Physical devices properties");
+  BluCat::INT::core.log.message(Log::Level::Trace, "Physical devices properties");
 #endif
 
-  BluCat::core.vk_devices.reserve(devices_count);
+  BluCat::INT::core.vk_devices.reserve(devices_count);
   for(auto i = 0; i < devices_count; i++)
   {
     // Use swapchain on first device.
     if(i == 0)
     {
-      BluCat::core.vk_devices.emplace_back(vk_physical_devices[i], true);
-      BluCat::core.vk_device_with_swapchain = &BluCat::core.vk_devices[i];
+      BluCat::INT::core.vk_devices.emplace_back(vk_physical_devices[i], true);
+      BluCat::INT::core.vk_device_with_swapchain = &BluCat::INT::core.vk_devices[i];
     }
     else
-      BluCat::core.vk_devices.emplace_back(vk_physical_devices[i], false);
+      BluCat::INT::core.vk_devices.emplace_back(vk_physical_devices[i], false);
   }
 }
 
 void
 unload_devices(void *obj)
 {
-  BluCat::core.vk_devices.clear();
+  BluCat::INT::core.vk_devices.clear();
 }
 
 static void
 load_swapchain(void *obj)
 {
-  try { BluCat::core.vk_swapchain = new BluCat::Swapchain(); }
+  try { BluCat::INT::core.vk_swapchain = new BluCat::GRA::Swapchain(); }
   catch(const CommandError &error)
   {
     std::string error_message{"Failed to create swapchain → "};
@@ -196,7 +196,7 @@ load_swapchain(void *obj)
 void
 unload_swapchain(void *obj)
 {
-  delete BluCat::core.vk_swapchain;
+  delete BluCat::INT::core.vk_swapchain;
 }
 
 void
@@ -204,7 +204,7 @@ load_framebuffer(void *obj)
 {
   try
   {
-    BluCat::core.vk_framebuffer = new BluCat::Framebuffer();
+    BluCat::INT::core.vk_framebuffer = new BluCat::GRA::Framebuffer();
   }
   catch(const CommandError &e)
   {
@@ -215,7 +215,7 @@ load_framebuffer(void *obj)
 void
 unload_framebuffer(void *obj)
 {
-  delete BluCat::core.vk_framebuffer;
+  delete BluCat::INT::core.vk_framebuffer;
 }
 
 void
@@ -223,7 +223,7 @@ load_render_pass(void *obj)
 {
   try
   {
-    BluCat::core.vk_render_pass = new BluCat::RenderPass();
+    BluCat::INT::core.vk_render_pass = new BluCat::GRA::RenderPass();
   }
   catch(const CommandError &e)
   {
@@ -234,7 +234,7 @@ load_render_pass(void *obj)
 void
 unload_render_pass(void *obj)
 {
-  delete BluCat::core.vk_render_pass;
+  delete BluCat::INT::core.vk_render_pass;
 }
 
 void
@@ -242,7 +242,7 @@ load_descriptor_set_layout(void *obj)
 {
   try
   {
-    BluCat::core.vk_descriptor_set_layout = new BluCat::DescriptorSetLayout();
+    BluCat::INT::core.vk_descriptor_set_layout = new BluCat::GRA::DescriptorSetLayout();
   }
   catch(const CommandError &e)
   {
@@ -253,7 +253,7 @@ load_descriptor_set_layout(void *obj)
 void
 unload_descriptor_set_layout(void *obj)
 {
-  delete BluCat::core.vk_descriptor_set_layout;
+  delete BluCat::INT::core.vk_descriptor_set_layout;
 }
 
 void
@@ -261,8 +261,8 @@ load_graphics_pipeline_3d_layout(void *obj)
 {
   try
   {
-    BluCat::core.vk_graphics_pipeline_3d_layout =
-      new BluCat::GraphicsPipeline3DLayout();
+    BluCat::INT::core.vk_graphics_pipeline_3d_layout =
+      new BluCat::GRA::GraphicsPipeline3DLayout();
   }
   catch(const CommandError &e)
   {
@@ -273,7 +273,7 @@ load_graphics_pipeline_3d_layout(void *obj)
 void
 unload_graphics_pipeline_3d_layout(void *obj)
 {
-  delete BluCat::core.vk_graphics_pipeline_3d_layout;
+  delete BluCat::INT::core.vk_graphics_pipeline_3d_layout;
 }
 
 void
@@ -281,8 +281,8 @@ load_graphics_pipeline_2d_solid_layout(void *obj)
 {
   try
   {
-    BluCat::core.vk_graphics_pipeline_2d_solid_layout =
-      new BluCat::GraphicsPipeline2DSolidLayout();
+    BluCat::INT::core.vk_graphics_pipeline_2d_solid_layout =
+      new BluCat::GRA::GraphicsPipeline2DSolidLayout();
   }
   catch(const CommandError &e)
   {
@@ -293,7 +293,7 @@ load_graphics_pipeline_2d_solid_layout(void *obj)
 void
 unload_graphics_pipeline_2d_solid_layout(void *obj)
 {
-  delete BluCat::core.vk_graphics_pipeline_2d_solid_layout;
+  delete BluCat::INT::core.vk_graphics_pipeline_2d_solid_layout;
 }
 
 void
@@ -301,8 +301,8 @@ load_graphics_pipeline_2d_wired_layout(void *obj)
 {
   try
   {
-    BluCat::core.vk_graphics_pipeline_2d_wired_layout =
-      new BluCat::GraphicsPipeline2DWiredLayout();
+    BluCat::INT::core.vk_graphics_pipeline_2d_wired_layout =
+      new BluCat::GRA::GraphicsPipeline2DWiredLayout();
   }
   catch(const CommandError &e)
   {
@@ -313,7 +313,7 @@ load_graphics_pipeline_2d_wired_layout(void *obj)
 void
 unload_graphics_pipeline_2d_wired_layout(void *obj)
 {
-  delete BluCat::core.vk_graphics_pipeline_2d_wired_layout;
+  delete BluCat::INT::core.vk_graphics_pipeline_2d_wired_layout;
 }
 
 void
@@ -321,7 +321,7 @@ load_light(void *obj)
 {
   try
   {
-    BluCat::core.vk_light = new BluCat::Light();
+    BluCat::INT::core.vk_light = new BluCat::GRA::Light();
   }
   catch(const CommandError &e)
   {
@@ -332,7 +332,7 @@ load_light(void *obj)
 void
 unload_light(void *obj)
 {
-  delete BluCat::core.vk_light;
+  delete BluCat::INT::core.vk_light;
 }
 
 void
@@ -340,8 +340,8 @@ load_graphics_pipeline_3d(void *obj)
 {
   try
   {
-    BluCat::core.vk_graphics_pipeline_3d =
-      std::make_unique<BluCat::GraphicsPipeline3D>();
+    BluCat::INT::core.vk_graphics_pipeline_3d =
+      std::make_unique<BluCat::GRA::GraphicsPipeline3D>();
   }
   catch(const CommandError &e)
   {
@@ -352,7 +352,7 @@ load_graphics_pipeline_3d(void *obj)
 void
 unload_graphics_pipeline_3d(void *obj)
 {
-  BluCat::core.vk_graphics_pipeline_3d = nullptr;
+  BluCat::INT::core.vk_graphics_pipeline_3d = nullptr;
 }
 
 void
@@ -360,8 +360,8 @@ load_graphics_pipeline_3d_skeletal(void *obj)
 {
   try
   {
-    BluCat::core.vk_graphics_pipeline_3d_skeletal =
-      std::make_unique<BluCat::GraphicsPipeline3DSkeletal>();
+    BluCat::INT::core.vk_graphics_pipeline_3d_skeletal =
+      std::make_unique<BluCat::GRA::GraphicsPipeline3DSkeletal>();
   }
   catch(const CommandError &e)
   {
@@ -372,7 +372,7 @@ load_graphics_pipeline_3d_skeletal(void *obj)
 void
 unload_graphics_pipeline_3d_skeletal(void *obj)
 {
-  BluCat::core.vk_graphics_pipeline_3d_skeletal = nullptr;
+  BluCat::INT::core.vk_graphics_pipeline_3d_skeletal = nullptr;
 }
 
 void
@@ -380,8 +380,8 @@ load_graphics_pipeline_sprite_3d(void *obj)
 {
   try
   {
-    BluCat::core.vk_graphics_pipeline_sprite_3d =
-      std::make_unique<BluCat::GraphicsPipelineSprite3D>();
+    BluCat::INT::core.vk_graphics_pipeline_sprite_3d =
+      std::make_unique<BluCat::GRA::GraphicsPipelineSprite3D>();
   }
   catch(const CommandError &e)
   {
@@ -392,7 +392,7 @@ load_graphics_pipeline_sprite_3d(void *obj)
 void
 unload_graphics_pipeline_sprite_3d(void *obj)
 {
-  BluCat::core.vk_graphics_pipeline_sprite_3d = nullptr;
+  BluCat::INT::core.vk_graphics_pipeline_sprite_3d = nullptr;
 }
 
 void
@@ -400,8 +400,8 @@ load_graphics_pipeline_2d_solid(void *obj)
 {
   try
   {
-    BluCat::core.vk_graphics_pipeline_2d_solid =
-      std::make_unique<BluCat::GraphicsPipeline2DSolid>();
+    BluCat::INT::core.vk_graphics_pipeline_2d_solid =
+      std::make_unique<BluCat::GRA::GraphicsPipeline2DSolid>();
   }
   catch(const CommandError &e)
   {
@@ -412,7 +412,7 @@ load_graphics_pipeline_2d_solid(void *obj)
 void
 unload_graphics_pipeline_2d_solid(void *obj)
 {
-  BluCat::core.vk_graphics_pipeline_2d_solid = nullptr;
+  BluCat::INT::core.vk_graphics_pipeline_2d_solid = nullptr;
 }
 
 void
@@ -420,8 +420,8 @@ load_graphics_pipeline_2d_wired(void *obj)
 {
   try
   {
-    BluCat::core.vk_graphics_pipeline_2d_wired =
-      std::make_unique<BluCat::GraphicsPipeline2DWired>();
+    BluCat::INT::core.vk_graphics_pipeline_2d_wired =
+      std::make_unique<BluCat::GRA::GraphicsPipeline2DWired>();
   }
   catch(const CommandError &e)
   {
@@ -432,7 +432,7 @@ load_graphics_pipeline_2d_wired(void *obj)
 void
 unload_graphics_pipeline_2d_wired(void *obj)
 {
-  BluCat::core.vk_graphics_pipeline_2d_wired = nullptr;
+  BluCat::INT::core.vk_graphics_pipeline_2d_wired = nullptr;
 }
 
 void
@@ -442,11 +442,11 @@ load_renderer(void *obj)
   {
     glm::vec4 region(
       0.f, 0.f,
-      static_cast<float>(BluCat::core.display_width),
-      static_cast<float>(BluCat::core.display_height));
-		BluCat::core.vk_renderer = new BluCat::Renderer(
+      static_cast<float>(BluCat::INT::core.display_width),
+      static_cast<float>(BluCat::INT::core.display_height));
+		BluCat::INT::core.vk_renderer = new BluCat::GRA::Renderer(
       {},
-      {std::make_shared<BluCat::View3D>(region, region.z, region.w)});
+      {std::make_shared<BluCat::GRA::View3D>(region, region.z, region.w)});
   }
   catch(const CommandError &e)
   {
@@ -457,12 +457,12 @@ load_renderer(void *obj)
 void
 unload_renderer(void *obj)
 {
-  delete BluCat::core.vk_renderer;
+  delete BluCat::INT::core.vk_renderer;
 }
 
 }
 
-namespace BluCat
+namespace BluCat::INT
 {
 
 std::random_device random_seed;
diff --git a/src/blu_cat/int/core.hpp b/src/blu_cat/int/core.hpp
new file mode 100644
index 0000000..0900b81
--- /dev/null
+++ b/src/blu_cat/int/core.hpp
@@ -0,0 +1,123 @@
+/*
+ * Copyright 2022-2024 Frederico de Oliveira Linhares
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef BLU_CAT_INT_CORE_H
+#define BLU_CAT_INT_CORE_H 1
+
+#define BLU_CAT_VERSION_MAJOR 0
+#define BLU_CAT_VERSION_MINOR 1
+#define BLU_CAT_VERSION_PATCH 0
+
+#include <chrono>
+#include <cstdint>
+#include <memory>
+#include <random>
+
+#include "../com/command.hpp"
+#include "../com/job_queue.hpp"
+#include "../com/worker.hpp"
+#include "../gra/device.hpp"
+#include "../gra/descriptor_set_layout.hpp"
+#include "../gra/framebuffer.hpp"
+#include "../gra/graphics_pipeline_2d_solid_layout.hpp"
+#include "../gra/graphics_pipeline_2d_wired_layout.hpp"
+#include "../gra/graphics_pipeline_2d_solid.hpp"
+#include "../gra/graphics_pipeline_2d_wired.hpp"
+#include "../gra/graphics_pipeline_3d_layout.hpp"
+#include "../gra/graphics_pipeline_3d.hpp"
+#include "../gra/graphics_pipeline_3d_skeletal.hpp"
+#include "../gra/graphics_pipeline_sprite_3d.hpp"
+#include "../gra/light.hpp"
+#include "../gra/log.hpp"
+#include "../gra/render_pass.hpp"
+#include "../gra/renderer.hpp"
+#include "../gra/swapchain.hpp"
+#include "../gra/vulkan.hpp"
+
+namespace BluCat::INT
+{
+
+extern std::random_device random_seed;
+extern std::mt19937 random_number_generator;
+
+struct Core
+{
+  static const CommandChain loader;
+
+  Log::Logger log;
+
+  COM::JobQueue job_queue;
+  std::vector<COM::Worker> workers;
+  std::vector<std::thread> threads;
+
+  /// Text displayed in the game window.
+  std::string game_name;
+
+  /**
+   * @{
+   * This is the ammount of pixel that the games uses when rendering to the
+   * screen.
+   */
+  uint32_t display_width, display_height;
+  /// @}
+
+  int game_version_major, game_version_minor, game_version_patch;
+
+  uint32_t fps;
+  std::chrono::duration<long long, std::milli> max_frame_duration;
+  float delta_time;
+
+  FT_Library font_library;
+
+  VkSurfaceKHR window_surface;
+  VkInstance vk_instance;
+
+#ifdef DEBUG
+  VkDebugUtilsMessengerEXT vk_callback;
+#endif
+
+  // Vulkan devices.
+  std::vector<BluCat::GRA::Device> vk_devices;
+  BluCat::GRA::Device *vk_device_with_swapchain;
+  BluCat::GRA::Swapchain *vk_swapchain;
+
+  BluCat::GRA::Framebuffer *vk_framebuffer;
+  BluCat::GRA::RenderPass *vk_render_pass;
+  BluCat::GRA::DescriptorSetLayout *vk_descriptor_set_layout;
+  BluCat::GRA::GraphicsPipeline3DLayout *vk_graphics_pipeline_3d_layout;
+  BluCat::GRA::GraphicsPipeline2DSolidLayout
+	*vk_graphics_pipeline_2d_solid_layout;
+  BluCat::GRA::GraphicsPipeline2DWiredLayout
+	*vk_graphics_pipeline_2d_wired_layout;
+  BluCat::GRA::Light *vk_light;
+  std::unique_ptr<BluCat::GRA::GraphicsPipeline3D> vk_graphics_pipeline_3d;
+  std::unique_ptr<BluCat::GRA::GraphicsPipeline3DSkeletal>
+  vk_graphics_pipeline_3d_skeletal;
+  std::unique_ptr<BluCat::GRA::GraphicsPipelineSprite3D>
+	vk_graphics_pipeline_sprite_3d;
+  std::unique_ptr<BluCat::GRA::GraphicsPipeline2DSolid>
+	vk_graphics_pipeline_2d_solid;
+  std::unique_ptr<BluCat::GRA::GraphicsPipeline2DWired>
+	vk_graphics_pipeline_2d_wired;
+
+  BluCat::GRA::Renderer *vk_renderer;
+};
+
+extern Core core;
+
+}
+
+#endif /* BLU_CAT_INT_CORE_H */
diff --git a/src/blucat/core.hpp b/src/blucat/core.hpp
deleted file mode 100644
index decf319..0000000
--- a/src/blucat/core.hpp
+++ /dev/null
@@ -1,118 +0,0 @@
-/*
- * Copyright 2022-2024 Frederico de Oliveira Linhares
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#ifndef CANDY_GEAR_BLUCAT_CORE_H
-#define CANDY_GEAR_BLUCAT_CORE_H 1
-
-#define BLU_CAT_VERSION_MAJOR 0
-#define BLU_CAT_VERSION_MINOR 1
-#define BLU_CAT_VERSION_PATCH 0
-
-#include <chrono>
-#include <cstdint>
-#include <memory>
-#include <random>
-
-#include "command.hpp"
-#include "device.hpp"
-#include "descriptor_set_layout.hpp"
-#include "framebuffer.hpp"
-#include "graphics_pipeline_2d_solid_layout.hpp"
-#include "graphics_pipeline_2d_wired_layout.hpp"
-#include "graphics_pipeline_2d_solid.hpp"
-#include "graphics_pipeline_2d_wired.hpp"
-#include "graphics_pipeline_3d_layout.hpp"
-#include "graphics_pipeline_3d.hpp"
-#include "graphics_pipeline_3d_skeletal.hpp"
-#include "graphics_pipeline_sprite_3d.hpp"
-#include "job_queue.hpp"
-#include "light.hpp"
-#include "log.hpp"
-#include "render_pass.hpp"
-#include "renderer.hpp"
-#include "swapchain.hpp"
-#include "vulkan.hpp"
-#include "worker.hpp"
-
-namespace BluCat
-{
-
-extern std::random_device random_seed;
-extern std::mt19937 random_number_generator;
-
-struct Core
-{
-  static const CommandChain loader;
-
-  Log::Logger log;
-
-  JobQueue job_queue;
-  std::vector<Worker> workers;
-  std::vector<std::thread> threads;
-
-  /// Text displayed in the game window.
-  std::string game_name;
-
-  /**
-   * @{
-   * This is the ammount of pixel that the games uses when rendering to the
-   * screen.
-   */
-  uint32_t display_width, display_height;
-  /// @}
-
-  int game_version_major, game_version_minor, game_version_patch;
-
-  uint32_t fps;
-  std::chrono::duration<long long, std::milli> max_frame_duration;
-  float delta_time;
-
-  FT_Library font_library;
-
-  VkSurfaceKHR window_surface;
-  VkInstance vk_instance;
-
-#ifdef DEBUG
-  VkDebugUtilsMessengerEXT vk_callback;
-#endif
-
-  // Vulkan devices.
-  std::vector<Device> vk_devices;
-  Device *vk_device_with_swapchain;
-  Swapchain *vk_swapchain;
-
-  Framebuffer *vk_framebuffer;
-  RenderPass *vk_render_pass;
-  DescriptorSetLayout *vk_descriptor_set_layout;
-  GraphicsPipeline3DLayout *vk_graphics_pipeline_3d_layout;
-  GraphicsPipeline2DSolidLayout *vk_graphics_pipeline_2d_solid_layout;
-  GraphicsPipeline2DWiredLayout *vk_graphics_pipeline_2d_wired_layout;
-  Light *vk_light;
-  std::unique_ptr<GraphicsPipeline3D> vk_graphics_pipeline_3d;
-  std::unique_ptr<GraphicsPipeline3DSkeletal>
-  vk_graphics_pipeline_3d_skeletal;
-  std::unique_ptr<GraphicsPipelineSprite3D> vk_graphics_pipeline_sprite_3d;
-  std::unique_ptr<GraphicsPipeline2DSolid> vk_graphics_pipeline_2d_solid;
-  std::unique_ptr<GraphicsPipeline2DWired> vk_graphics_pipeline_2d_wired;
-
-  Renderer *vk_renderer;
-};
-
-extern Core core;
-
-}
-
-#endif /* CANDY_GEAR_BLUCAT_CORE_H */
diff --git a/src/candy_gear.cpp b/src/candy_gear/candy_gear.cpp
index e8add70..b1758a4 100644
--- a/src/candy_gear.cpp
+++ b/src/candy_gear/candy_gear.cpp
@@ -30,7 +30,7 @@ cg_mCandyGear_set_game_name(mrb_state *mrb, mrb_value self)
   mrb_value name;
 
   mrb_get_args(mrb, "S", &name);
-  BluCat::core.game_name = RSTRING_PTR(name);
+  BluCat::INT::core.game_name = RSTRING_PTR(name);
 
   return self;
 }
@@ -42,8 +42,8 @@ cg_mCandyGear_set_views(mrb_state *mrb, mrb_value self)
   mrb_value *array;
   mrb_int array_len;
 
-  std::vector<std::shared_ptr<BluCat::View2D>> views_2d;
-  std::vector<std::shared_ptr<BluCat::View3D>> views_3d;
+  std::vector<std::shared_ptr<BluCat::GRA::View2D>> views_2d;
+  std::vector<std::shared_ptr<BluCat::GRA::View3D>> views_3d;
 
   cg_m = mrb_module_get(mrb, "CandyGear");
   cg_cView2D = mrb_class_get_under(mrb, cg_m, "View2D");
@@ -54,12 +54,12 @@ cg_mCandyGear_set_views(mrb_state *mrb, mrb_value self)
   {
     if(mrb_obj_is_kind_of(mrb, array[i], cg_cView2D))
     {
-      auto v = (std::shared_ptr<BluCat::View2D>*)DATA_PTR(array[i]);
+      auto v = (std::shared_ptr<BluCat::GRA::View2D>*)DATA_PTR(array[i]);
       views_2d.push_back(*v);
     }
     else if(mrb_obj_is_kind_of(mrb, array[i], cg_cView3D))
     {
-      auto v = (std::shared_ptr<BluCat::View3D>*)DATA_PTR(array[i]);
+      auto v = (std::shared_ptr<BluCat::GRA::View3D>*)DATA_PTR(array[i]);
       views_3d.push_back(*v);
     }
   }
@@ -67,8 +67,8 @@ cg_mCandyGear_set_views(mrb_state *mrb, mrb_value self)
   // A Renderer need at least one view to work.
   if(views_2d.size() > 0 || views_3d.size() > 0)
   {
-    delete BluCat::core.vk_renderer;
-    BluCat::core.vk_renderer = new BluCat::Renderer({views_2d, views_3d});
+    delete BluCat::INT::core.vk_renderer;
+    BluCat::INT::core.vk_renderer = new BluCat::GRA::Renderer({views_2d, views_3d});
   }
 
   return self;
@@ -96,7 +96,7 @@ cg_mCandyGear_log(mrb_state *mrb, mrb_value self)
   else
     log_lvl = Log::Level::Fatal;
 
-  BluCat::core.log.message(log_lvl, message);
+  BluCat::INT::core.log.message(log_lvl, message);
 
   return self;
 }
diff --git a/src/candy_gear.hpp b/src/candy_gear/candy_gear.hpp
index 3ec92b3..3ec92b3 100644
--- a/src/candy_gear.hpp
+++ b/src/candy_gear/candy_gear.hpp
diff --git a/src/core.cpp b/src/candy_gear/core.cpp
index dd68edb..28f5a15 100644
--- a/src/core.cpp
+++ b/src/candy_gear/core.cpp
@@ -64,16 +64,16 @@ load_game(void *obj)
   FILE *fp;
   mrb_value main_obj{mrb_top_self(cg_core.mrb)};
 
-  BluCat::core.game_name = "CandyGear Game";
+  BluCat::INT::core.game_name = "CandyGear Game";
 
-  BluCat::core.display_width = 800;
-  BluCat::core.display_height = 600;
+  BluCat::INT::core.display_width = 800;
+  BluCat::INT::core.display_height = 600;
 
-  BluCat::core.game_version_major = 0;
-  BluCat::core.game_version_minor = 1;
-  BluCat::core.game_version_patch = 0;
+  BluCat::INT::core.game_version_major = 0;
+  BluCat::INT::core.game_version_minor = 1;
+  BluCat::INT::core.game_version_patch = 0;
 
-  BluCat::core.fps = 30;
+  BluCat::INT::core.fps = 30;
 
   mrb_define_module(cg_core.mrb, "CandyGear");
   cg_candy_gear_init_config(cg_core.mrb);
@@ -166,9 +166,9 @@ load_window(void *obj)
 {
   cg_core.window = NULL;
   cg_core.window = SDL_CreateWindow(
-    BluCat::core.game_name.c_str(),
+    BluCat::INT::core.game_name.c_str(),
 		SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED,
-		BluCat::core.display_width, BluCat::core.display_height,
+		BluCat::INT::core.display_width, BluCat::INT::core.display_height,
     SDL_WINDOW_VULKAN);
   if(cg_core.window == NULL)
   {
@@ -230,12 +230,12 @@ load_vk_instance(void *obj)
 		}
 
 #ifdef DEBUG
-		BluCat::core.log.message(Log::Level::Trace, "Enabled VK extensions.");
+		BluCat::INT::core.log.message(Log::Level::Trace, "Enabled VK extensions.");
 		for(auto vk_extension: vk_extensions)
 		{
 			std::string message{"Extension name: "};
 			message += vk_extension;
-			BluCat::core.log.message(Log::Level::Trace, message);
+			BluCat::INT::core.log.message(Log::Level::Trace, message);
 		}
 #endif
 	}
@@ -252,7 +252,7 @@ load_vk_instance(void *obj)
 																			 vk_available_layers.data());
 		vk_available_layers_names.resize(vk_available_layers_count);
 #ifdef DEBUG
-		BluCat::core.log.message(
+		BluCat::INT::core.log.message(
 			Log::Level::Trace, "Available VK instance layers.");
 #endif
 		for(uint32_t i = 0; i < vk_available_layers_count; i++)
@@ -266,7 +266,7 @@ load_vk_instance(void *obj)
 				std::endl;
 			message << "Implementation version: " <<
 				vk_available_layers[i].implementationVersion << std::endl;
-			BluCat::core.log.message(Log::Level::Trace, message.str());
+			BluCat::INT::core.log.message(Log::Level::Trace, message.str());
 #endif
 
 			vk_available_layers_names[i] = vk_available_layers[i].layerName;
@@ -283,12 +283,12 @@ load_vk_instance(void *obj)
 		VkApplicationInfo app_info;
 		app_info.sType = VK_STRUCTURE_TYPE_APPLICATION_INFO;
 		app_info.pNext = nullptr;
-		app_info.pApplicationName = BluCat::core.game_name.c_str();
+		app_info.pApplicationName = BluCat::INT::core.game_name.c_str();
 		app_info.applicationVersion = VK_MAKE_VERSION(
-			BluCat::core.game_version_major,
-			BluCat::core.game_version_minor,
-			BluCat::core.game_version_patch);
-		app_info.pEngineName = "BluCat";
+			BluCat::INT::core.game_version_major,
+			BluCat::INT::core.game_version_minor,
+			BluCat::INT::core.game_version_patch);
+		app_info.pEngineName = "BluCat::GRA";
 		app_info.engineVersion = VK_MAKE_VERSION(
 			BLU_CAT_VERSION_MAJOR,
 			BLU_CAT_VERSION_MINOR,
@@ -306,7 +306,7 @@ load_vk_instance(void *obj)
 		create_info.ppEnabledLayerNames = vk_required_layers_names.data();
 
 		VkResult result =
-			vkCreateInstance(&create_info, nullptr, &BluCat::core.vk_instance);
+			vkCreateInstance(&create_info, nullptr, &BluCat::INT::core.vk_instance);
 		if(result != VK_SUCCESS)
 		{
 			std::string error{""};
@@ -327,14 +327,14 @@ load_vk_instance(void *obj)
 void
 unload_vk_instance(void *obj)
 {
-	vkDestroyInstance(BluCat::core.vk_instance, nullptr);
+	vkDestroyInstance(BluCat::INT::core.vk_instance, nullptr);
 }
 
 void
 load_window_surface(void *obj)
 {
   if(!SDL_Vulkan_CreateSurface(
-       cg_core.window, BluCat::core.vk_instance, &BluCat::core.window_surface))
+       cg_core.window, BluCat::INT::core.vk_instance, &BluCat::INT::core.window_surface))
   {
     std::string error{"Failed to create a window surface → "};
     error += SDL_GetError();
@@ -346,19 +346,19 @@ void
 unload_window_surface(void *obj)
 {
   vkDestroySurfaceKHR(
-		BluCat::core.vk_instance, BluCat::core.window_surface, nullptr);
+		BluCat::INT::core.vk_instance, BluCat::INT::core.window_surface, nullptr);
 }
 
 void
 load_blucat(void *obj)
 {
-	BluCat::core.loader.execute(nullptr);
+	BluCat::INT::core.loader.execute(nullptr);
 }
 
 void
 unload_blucat(void *obj)
 {
-	BluCat::core.loader.revert(nullptr);
+	BluCat::INT::core.loader.revert(nullptr);
 }
 
 void
diff --git a/src/core.hpp b/src/candy_gear/core.hpp
index e7caf8b..60d8339 100644
--- a/src/core.hpp
+++ b/src/candy_gear/core.hpp
@@ -17,10 +17,6 @@
 #ifndef CANDY_GEAR_CORE_H
 #define CANDY_GEAR_CORE_H 1
 
-#define CANDY_GEAR_VERSION_MAJOR 0
-#define CANDY_GEAR_VERSION_MINOR 1
-#define CANDY_GEAR_VERSION_PATCH 0
-
 #include <mruby.h>
 #include <mruby/class.h>
 #include <mruby/compile.h>
@@ -41,7 +37,7 @@
 #include <ft2build.h>
 #include FT_FREETYPE_H
 
-#include "blucat/core.hpp"
+#include "../blu_cat/int/core.hpp"
 
 /**
  * The Core class stores all global states that the engine needs to work.
diff --git a/src/font.cpp b/src/candy_gear/font.cpp
index 919d271..f9cbf44 100644
--- a/src/font.cpp
+++ b/src/candy_gear/font.cpp
@@ -16,12 +16,12 @@
 
 #include "font.hpp"
 
-#include "blucat/font.hpp"
+#include "../blu_cat/gra/font.hpp"
 
 void
 cg_free_font(mrb_state *mrb, void *obj)
 {
-  auto ptr = static_cast<BluCat::Font*>(obj);
+  auto ptr = static_cast<BluCat::GRA::Font*>(obj);
 
   ptr->~Font();
   mrb_free(mrb, ptr);
@@ -33,18 +33,18 @@ cg_font_type = {"CG_Font", cg_free_font};
 static mrb_value
 cg_cFont_initialize(mrb_state *mrb, mrb_value self)
 {
-  BluCat::Font *ptr;
+  BluCat::GRA::Font *ptr;
   const char *font_path;
   mrb_int font_size;
 
   mrb_get_args(mrb, "zi", &font_path, &font_size);
-  ptr = (BluCat::Font*)DATA_PTR(self);
+  ptr = (BluCat::GRA::Font*)DATA_PTR(self);
   if(ptr) mrb_free(mrb, ptr);
-  ptr = (BluCat::Font*)mrb_malloc(mrb, sizeof(BluCat::Font));
+  ptr = (BluCat::GRA::Font*)mrb_malloc(mrb, sizeof(BluCat::GRA::Font));
 
   try
   {
-    new(ptr)BluCat::Font(font_path, font_size);
+    new(ptr)BluCat::GRA::Font(font_path, font_size);
   }
   catch(const std::invalid_argument &e)
   {
diff --git a/src/font.hpp b/src/candy_gear/font.hpp
index 0128ea0..0128ea0 100644
--- a/src/font.hpp
+++ b/src/candy_gear/font.hpp
diff --git a/src/graphic.cpp b/src/candy_gear/graphic.cpp
index a991130..ad701d1 100644
--- a/src/graphic.cpp
+++ b/src/candy_gear/graphic.cpp
@@ -24,7 +24,7 @@ cg_mCandyGear_set_display_width(mrb_state *mrb, mrb_value self)
   mrb_int width;
 
   mrb_get_args(mrb, "i", &width);
-  BluCat::core.display_width = width;
+  BluCat::INT::core.display_width = width;
 
   return self;
 }
@@ -35,7 +35,7 @@ cg_mCandyGear_set_display_height(mrb_state *mrb, mrb_value self)
   mrb_int height;
 
   mrb_get_args(mrb, "i", &height);
-  BluCat::core.display_height = height;
+  BluCat::INT::core.display_height = height;
 
   return self;
 }
@@ -46,7 +46,7 @@ cg_mCandyGear_set_fps(mrb_state *mrb, mrb_value self)
   mrb_int fps;
 
   mrb_get_args(mrb, "i", &fps);
-  BluCat::core.fps = fps;
+  BluCat::INT::core.fps = fps;
 
   return self;
 }
diff --git a/src/graphic.hpp b/src/candy_gear/graphic.hpp
index fbd9df8..fbd9df8 100644
--- a/src/graphic.hpp
+++ b/src/candy_gear/graphic.hpp
diff --git a/src/key.cpp b/src/candy_gear/key.cpp
index 615119c..615119c 100644
--- a/src/key.cpp
+++ b/src/candy_gear/key.cpp
diff --git a/src/key.hpp b/src/candy_gear/key.hpp
index d3f4f5f..d3f4f5f 100644
--- a/src/key.hpp
+++ b/src/candy_gear/key.hpp
diff --git a/src/main.cpp b/src/candy_gear/main.cpp
index 3627c9c..353b6bf 100644
--- a/src/main.cpp
+++ b/src/candy_gear/main.cpp
@@ -29,7 +29,7 @@ int main(int argc, char *argv[])
   SDL_Event event;
 
   // Random numbers
-  BluCat::random_number_generator.seed(BluCat::random_seed());
+  BluCat::INT::random_number_generator.seed(BluCat::INT::random_seed());
 
   cg_core.game_file = argv[1];
   cg_core.mrb = mrb_open();
@@ -37,7 +37,7 @@ int main(int argc, char *argv[])
   try{ cg_sCore::loader.execute(nullptr); }
   catch(const CommandError &error)
   {
-    BluCat::core.log.message(Log::Level::Fatal, error.what());
+    BluCat::INT::core.log.message(Log::Level::Fatal, error.what());
     mrb_close(cg_core.mrb);
     return 1;
   }
@@ -93,15 +93,15 @@ int main(int argc, char *argv[])
     }
     else
     {
-      BluCat::core.vk_renderer->draw();
+      BluCat::INT::core.vk_renderer->draw();
 
       { // Timer
         auto frame_stop = steady_clock::now();
         auto frame_duration = frame_stop - frame_start;
 
         // If frame take less time than maximum allowed.
-        if(BluCat::core.max_frame_duration > frame_duration)
-          sleep_for(BluCat::core.max_frame_duration - frame_duration);
+        if(BluCat::INT::core.max_frame_duration > frame_duration)
+          sleep_for(BluCat::INT::core.max_frame_duration - frame_duration);
 
         frame_start = frame_stop;
       }
diff --git a/src/orientation_3d.cpp b/src/candy_gear/orientation_3d.cpp
index cb42984..cb42984 100644
--- a/src/orientation_3d.cpp
+++ b/src/candy_gear/orientation_3d.cpp
diff --git a/src/orientation_3d.hpp b/src/candy_gear/orientation_3d.hpp
index 45a8ab2..45a8ab2 100644
--- a/src/orientation_3d.hpp
+++ b/src/candy_gear/orientation_3d.hpp
diff --git a/src/skeletal_mesh.cpp b/src/candy_gear/skeletal_mesh.cpp
index 90cbeee..4af4419 100644
--- a/src/skeletal_mesh.cpp
+++ b/src/candy_gear/skeletal_mesh.cpp
@@ -18,12 +18,12 @@
 
 #include "orientation_3d.hpp"
 #include "vector_3d.hpp"
-#include "blucat/skeletal_mesh.hpp"
+#include "../blu_cat/gra/skeletal_mesh.hpp"
 
 void
 cg_free_skeletal_mesh(mrb_state *mrb, void* obj)
 {
-  auto ptr = static_cast<std::shared_ptr<BluCat::SkeletalMesh>*>(obj);
+  auto ptr = static_cast<std::shared_ptr<BluCat::GRA::SkeletalMesh>*>(obj);
 
   ptr->~shared_ptr();
   mrb_free(mrb, ptr);
@@ -37,16 +37,16 @@ cg_cSkeletalMesh_initialize(mrb_state *mrb, mrb_value self)
 {
   const char *file_path;
 
-  std::shared_ptr<BluCat::SkeletalMesh> *ptr;
+  std::shared_ptr<BluCat::GRA::SkeletalMesh> *ptr;
 
   mrb_get_args(mrb, "z", &file_path);
-  ptr = (std::shared_ptr<BluCat::SkeletalMesh>*)DATA_PTR(self);
+  ptr = (std::shared_ptr<BluCat::GRA::SkeletalMesh>*)DATA_PTR(self);
   if(ptr) mrb_free(mrb, ptr);
-  ptr = (std::shared_ptr<BluCat::SkeletalMesh>*)mrb_malloc(
-    mrb, sizeof(std::shared_ptr<BluCat::SkeletalMesh>));
+  ptr = (std::shared_ptr<BluCat::GRA::SkeletalMesh>*)mrb_malloc(
+    mrb, sizeof(std::shared_ptr<BluCat::GRA::SkeletalMesh>));
 
-  new(ptr)std::shared_ptr<BluCat::SkeletalMesh>(
-    std::make_shared<BluCat::SkeletalMesh>(file_path));
+  new(ptr)std::shared_ptr<BluCat::GRA::SkeletalMesh>(
+    std::make_shared<BluCat::GRA::SkeletalMesh>(file_path));
 
   mrb_data_init(self, ptr, &cg_skeletal_mesh_type);
   return self;
diff --git a/src/skeletal_mesh.hpp b/src/candy_gear/skeletal_mesh.hpp
index 476aa9b..476aa9b 100644
--- a/src/skeletal_mesh.hpp
+++ b/src/candy_gear/skeletal_mesh.hpp
diff --git a/src/skeletal_model.cpp b/src/candy_gear/skeletal_model.cpp
index f42306b..41d0c9a 100644
--- a/src/skeletal_model.cpp
+++ b/src/candy_gear/skeletal_model.cpp
@@ -20,12 +20,12 @@
 #include "vector_3d.hpp"
 #include "skeletal_mesh.hpp"
 #include "texture.hpp"
-#include "blucat/skeletal_model.hpp"
+#include "../blu_cat/gra/skeletal_model.hpp"
 
 void
 cg_free_skeletal_model(mrb_state *mrb, void *obj)
 {
-  auto ptr = static_cast<std::shared_ptr<BluCat::SkeletalModel>*>(obj);
+  auto ptr = static_cast<std::shared_ptr<BluCat::GRA::SkeletalModel>*>(obj);
 
   ptr->~shared_ptr();
   mrb_free(mrb, ptr);
@@ -37,23 +37,23 @@ const struct mrb_data_type cg_skeletal_model_type = {
 static mrb_value
 cg_cSkeletalModel_initialize(mrb_state *mrb, mrb_value self)
 {
-  std::shared_ptr<BluCat::SkeletalMesh> *skeletal_mesh;
-  std::shared_ptr<BluCat::Texture> *texture;
+  std::shared_ptr<BluCat::GRA::SkeletalMesh> *skeletal_mesh;
+  std::shared_ptr<BluCat::GRA::Texture> *texture;
   std::shared_ptr<glm::vec3> *position;
   std::shared_ptr<glm::quat> *orientation;
-  std::shared_ptr<BluCat::SkeletalModel> *ptr;
+  std::shared_ptr<BluCat::GRA::SkeletalModel> *ptr;
 
   mrb_get_args(
     mrb, "dddd", &skeletal_mesh, &cg_skeletal_mesh_type, &texture,
     &cg_texture_type, &position, &cg_vector_3d_type, &orientation,
     &cg_orientation_3d_type);
-  ptr = (std::shared_ptr<BluCat::SkeletalModel>*)DATA_PTR(self);
+  ptr = (std::shared_ptr<BluCat::GRA::SkeletalModel>*)DATA_PTR(self);
   if(ptr) mrb_free(mrb, ptr);
-  ptr = (std::shared_ptr<BluCat::SkeletalModel>*)mrb_malloc(
-    mrb, sizeof(std::shared_ptr<BluCat::SkeletalModel>));
+  ptr = (std::shared_ptr<BluCat::GRA::SkeletalModel>*)mrb_malloc(
+    mrb, sizeof(std::shared_ptr<BluCat::GRA::SkeletalModel>));
 
-  new(ptr)std::shared_ptr<BluCat::SkeletalModel>(
-    std::make_shared<BluCat::SkeletalModel>(
+  new(ptr)std::shared_ptr<BluCat::GRA::SkeletalModel>(
+    std::make_shared<BluCat::GRA::SkeletalModel>(
       *skeletal_mesh, *texture, *position, *orientation));
 
   mrb_data_init(self, ptr, &cg_skeletal_model_type);
@@ -63,7 +63,7 @@ cg_cSkeletalModel_initialize(mrb_state *mrb, mrb_value self)
 static mrb_value
 cg_cSkeletalModel_set_orientation(mrb_state *mrb, mrb_value self)
 {
-  auto ptr = (std::shared_ptr<BluCat::SkeletalModel>*)DATA_PTR(self);
+  auto ptr = (std::shared_ptr<BluCat::GRA::SkeletalModel>*)DATA_PTR(self);
   std::shared_ptr<glm::quat> *orientation;
 
   mrb_get_args(mrb, "d", &orientation, &cg_orientation_3d_type);
@@ -75,7 +75,7 @@ cg_cSkeletalModel_set_orientation(mrb_state *mrb, mrb_value self)
 static mrb_value
 cg_cSkeletalModel_set_position(mrb_state *mrb, mrb_value self)
 {
-  auto ptr = (std::shared_ptr<BluCat::SkeletalModel>*)DATA_PTR(self);
+  auto ptr = (std::shared_ptr<BluCat::GRA::SkeletalModel>*)DATA_PTR(self);
   std::shared_ptr<glm::vec3> *position;
 
   mrb_get_args(mrb, "d", &position, &cg_vector_3d_type);
@@ -87,7 +87,7 @@ cg_cSkeletalModel_set_position(mrb_state *mrb, mrb_value self)
 static mrb_value
 cg_cSkeletalModel_set_animation(mrb_state *mrb, mrb_value self)
 {
-  auto ptr = (std::shared_ptr<BluCat::SkeletalModel>*)DATA_PTR(self);
+  auto ptr = (std::shared_ptr<BluCat::GRA::SkeletalModel>*)DATA_PTR(self);
   mrb_int animation_index;
 
   mrb_get_args(mrb, "i", &animation_index);
@@ -99,10 +99,10 @@ cg_cSkeletalModel_set_animation(mrb_state *mrb, mrb_value self)
 static mrb_value
 cg_cSkeletalModel_draw(mrb_state *mrb, mrb_value self)
 {
-  auto ptr = (std::shared_ptr<BluCat::SkeletalModel>*)DATA_PTR(self);
+  auto ptr = (std::shared_ptr<BluCat::GRA::SkeletalModel>*)DATA_PTR(self);
 
-  auto &instances = BluCat::core.vk_renderer->skeletal_models_to_draw[
-    BluCat::core.vk_swapchain->current_frame][(*ptr)->skeletal_mesh];
+  auto &instances = BluCat::INT::core.vk_renderer->skeletal_models_to_draw[
+    BluCat::INT::core.vk_swapchain->current_frame][(*ptr)->skeletal_mesh];
   instances.push_back(*ptr);
 
   return self;
diff --git a/src/skeletal_model.hpp b/src/candy_gear/skeletal_model.hpp
index 05f9c2e..05f9c2e 100644
--- a/src/skeletal_model.hpp
+++ b/src/candy_gear/skeletal_model.hpp
diff --git a/src/sound.cpp b/src/candy_gear/sound.cpp
index 0b3518f..0b3518f 100644
--- a/src/sound.cpp
+++ b/src/candy_gear/sound.cpp
diff --git a/src/sound.hpp b/src/candy_gear/sound.hpp
index 2f483e3..2f483e3 100644
--- a/src/sound.hpp
+++ b/src/candy_gear/sound.hpp
diff --git a/src/sprite.cpp b/src/candy_gear/sprite.cpp
index 0041107..daf96a8 100644
--- a/src/sprite.cpp
+++ b/src/candy_gear/sprite.cpp
@@ -19,12 +19,12 @@
 #include "texture.hpp"
 #include "vector_4d.hpp"
 #include "view_2d.hpp"
-#include "blucat/sprite.hpp"
+#include "../blu_cat/gra/sprite.hpp"
 
 void
 cg_free_sprite(mrb_state *mrb, void* obj)
 {
-  auto ptr = static_cast<std::shared_ptr<BluCat::Sprite>*>(obj);
+  auto ptr = static_cast<std::shared_ptr<BluCat::GRA::Sprite>*>(obj);
 
   ptr->~shared_ptr();
   mrb_free(mrb, ptr);
@@ -37,22 +37,22 @@ cg_cSprite_initialize(mrb_state *mrb, mrb_value self)
 {
   mrb_float x, y, w, h;
   glm::vec4 vector_4d;
-  std::shared_ptr<BluCat::Texture> *texture;
-  std::shared_ptr<BluCat::Sprite> *ptr;
+  std::shared_ptr<BluCat::GRA::Texture> *texture;
+  std::shared_ptr<BluCat::GRA::Sprite> *ptr;
 
   mrb_get_args(
     mrb, "dffff", &texture, &cg_texture_type, &x, &y, &w, &h);
-  ptr = (std::shared_ptr<BluCat::Sprite>*)DATA_PTR(self);
+  ptr = (std::shared_ptr<BluCat::GRA::Sprite>*)DATA_PTR(self);
   if(ptr) mrb_free(mrb, ptr);
-  ptr = (std::shared_ptr<BluCat::Sprite>*)mrb_malloc(
-    mrb, sizeof(std::shared_ptr<BluCat::Sprite>));
+  ptr = (std::shared_ptr<BluCat::GRA::Sprite>*)mrb_malloc(
+    mrb, sizeof(std::shared_ptr<BluCat::GRA::Sprite>));
 
   vector_4d.x = x;
   vector_4d.y = y;
   vector_4d.z = w;
   vector_4d.w = h;
-  new(ptr)std::shared_ptr<BluCat::Sprite>(
-    std::make_shared<BluCat::Sprite>(*texture, vector_4d));
+  new(ptr)std::shared_ptr<BluCat::GRA::Sprite>(
+    std::make_shared<BluCat::GRA::Sprite>(*texture, vector_4d));
 
   mrb_data_init(self, ptr, &cg_sprite_type);
   return self;
@@ -62,9 +62,9 @@ static mrb_value
 cg_cSprite_draw(mrb_state *mrb, mrb_value self)
 {
   mrb_value view_value;
-  BluCat::View2D *view_2d;
+  BluCat::GRA::View2D *view_2d;
   mrb_float x, y, w, h, z_index{0.0};
-  auto ptr = (std::shared_ptr<BluCat::Sprite>*)DATA_PTR(self);
+  auto ptr = (std::shared_ptr<BluCat::GRA::Sprite>*)DATA_PTR(self);
 
   mrb_get_args(mrb, "offff|f", &view_value, &x, &y, &w, &h, &z_index);
 
@@ -72,7 +72,7 @@ cg_cSprite_draw(mrb_state *mrb, mrb_value self)
 
   glm::vec4 rect(x, y, x + w, y + h);
   auto &sprites_to_draw = view_2d->sprites_to_draw[
-    BluCat::core.vk_swapchain->current_frame];
+    BluCat::INT::core.vk_swapchain->current_frame];
   sprites_to_draw.emplace_back(*ptr, rect, z_index);
 
   return self;
diff --git a/src/sprite.hpp b/src/candy_gear/sprite.hpp
index 528f2f7..528f2f7 100644
--- a/src/sprite.hpp
+++ b/src/candy_gear/sprite.hpp
diff --git a/src/sprite_3d.cpp b/src/candy_gear/sprite_3d.cpp
index 6e6759f..d03b585 100644
--- a/src/sprite_3d.cpp
+++ b/src/candy_gear/sprite_3d.cpp
@@ -22,7 +22,7 @@
 void
 cg_free_sprite_3d(mrb_state *mrb, void *obj)
 {
-  auto ptr = static_cast<std::shared_ptr<BluCat::Sprite3D>*>(obj);
+  auto ptr = static_cast<std::shared_ptr<BluCat::GRA::Sprite3D>*>(obj);
 
   ptr->~shared_ptr();
   mrb_free(mrb, ptr);
@@ -34,21 +34,21 @@ const struct mrb_data_type cg_sprite_3d_type = {
 static mrb_value
 cg_cSprite3D_initialize(mrb_state *mrb, mrb_value self)
 {
-  std::shared_ptr<BluCat::Sprite> *sprite;
+  std::shared_ptr<BluCat::GRA::Sprite> *sprite;
   std::shared_ptr<glm::vec3> *position;
   mrb_float w, h;
-  std::shared_ptr<BluCat::Sprite3D> *ptr;
+  std::shared_ptr<BluCat::GRA::Sprite3D> *ptr;
 
   mrb_get_args(mrb, "ddff", &sprite, &cg_sprite_type,
 	       &position, &cg_vector_3d_type, &w, &h);
-  ptr = (std::shared_ptr<BluCat::Sprite3D>*)DATA_PTR(self);
+  ptr = (std::shared_ptr<BluCat::GRA::Sprite3D>*)DATA_PTR(self);
   if(ptr) mrb_free(mrb, ptr);
-  ptr = (std::shared_ptr<BluCat::Sprite3D>*)mrb_malloc(
-    mrb, sizeof(std::shared_ptr<BluCat::Sprite3D>));
+  ptr = (std::shared_ptr<BluCat::GRA::Sprite3D>*)mrb_malloc(
+    mrb, sizeof(std::shared_ptr<BluCat::GRA::Sprite3D>));
 
   glm::vec3 size{w, h, 0.0};
-  new(ptr)std::shared_ptr<BluCat::Sprite3D>(
-    std::make_shared<BluCat::Sprite3D>(*sprite, *position, size));
+  new(ptr)std::shared_ptr<BluCat::GRA::Sprite3D>(
+    std::make_shared<BluCat::GRA::Sprite3D>(*sprite, *position, size));
 
   mrb_data_init(self, ptr, &cg_sprite_3d_type);
   return self;
@@ -57,10 +57,10 @@ cg_cSprite3D_initialize(mrb_state *mrb, mrb_value self)
 static mrb_value
 cg_cSprite3D_draw(mrb_state *mrb, mrb_value self)
 {
-  auto ptr = (std::shared_ptr<BluCat::Sprite3D>*)DATA_PTR(self);
+  auto ptr = (std::shared_ptr<BluCat::GRA::Sprite3D>*)DATA_PTR(self);
 
-  auto &sprites_3d_to_draw = BluCat::core.vk_renderer->sprites_3d_to_draw[
-    BluCat::core.vk_swapchain->current_frame];
+  auto &sprites_3d_to_draw = BluCat::INT::core.vk_renderer->sprites_3d_to_draw[
+    BluCat::INT::core.vk_swapchain->current_frame];
   sprites_3d_to_draw.emplace_back(*ptr);
 
   return self;
diff --git a/src/sprite_3d.hpp b/src/candy_gear/sprite_3d.hpp
index 526c23a..526c23a 100644
--- a/src/sprite_3d.hpp
+++ b/src/candy_gear/sprite_3d.hpp
diff --git a/src/static_mesh.cpp b/src/candy_gear/static_mesh.cpp
index 3ae616e..9cb79ef 100644
--- a/src/static_mesh.cpp
+++ b/src/candy_gear/static_mesh.cpp
@@ -18,12 +18,12 @@
 
 #include "orientation_3d.hpp"
 #include "vector_3d.hpp"
-#include "blucat/static_mesh.hpp"
+#include "../blu_cat/gra/static_mesh.hpp"
 
 void
 cg_free_static_mesh(mrb_state *mrb, void* obj)
 {
-  auto ptr = static_cast<std::shared_ptr<BluCat::StaticMesh>*>(obj);
+  auto ptr = static_cast<std::shared_ptr<BluCat::GRA::StaticMesh>*>(obj);
 
   ptr->~shared_ptr();
   mrb_free(mrb, ptr);
@@ -37,16 +37,16 @@ cg_cStaticMesh_initialize(mrb_state *mrb, mrb_value self)
 {
   const char *file_path;
 
-  std::shared_ptr<BluCat::StaticMesh> *ptr;
+  std::shared_ptr<BluCat::GRA::StaticMesh> *ptr;
 
   mrb_get_args(mrb, "z", &file_path);
-  ptr = (std::shared_ptr<BluCat::StaticMesh>*)DATA_PTR(self);
+  ptr = (std::shared_ptr<BluCat::GRA::StaticMesh>*)DATA_PTR(self);
   if(ptr) mrb_free(mrb, ptr);
-  ptr = (std::shared_ptr<BluCat::StaticMesh>*)mrb_malloc(
-    mrb, sizeof(std::shared_ptr<BluCat::StaticMesh>));
+  ptr = (std::shared_ptr<BluCat::GRA::StaticMesh>*)mrb_malloc(
+    mrb, sizeof(std::shared_ptr<BluCat::GRA::StaticMesh>));
 
-  new(ptr)std::shared_ptr<BluCat::StaticMesh>(
-    std::make_shared<BluCat::StaticMesh>(file_path));
+  new(ptr)std::shared_ptr<BluCat::GRA::StaticMesh>(
+    std::make_shared<BluCat::GRA::StaticMesh>(file_path));
 
   mrb_data_init(self, ptr, &cg_static_mesh_type);
   return self;
diff --git a/src/static_mesh.hpp b/src/candy_gear/static_mesh.hpp
index 8f3b2d6..8f3b2d6 100644
--- a/src/static_mesh.hpp
+++ b/src/candy_gear/static_mesh.hpp
diff --git a/src/static_model.cpp b/src/candy_gear/static_model.cpp
index f9a1039..1a6eabe 100644
--- a/src/static_model.cpp
+++ b/src/candy_gear/static_model.cpp
@@ -20,12 +20,12 @@
 #include "static_mesh.hpp"
 #include "texture.hpp"
 #include "vector_3d.hpp"
-#include "blucat/static_model.hpp"
+#include "../blu_cat/gra/static_model.hpp"
 
 void
 cg_free_static_model(mrb_state *mrb, void *obj)
 {
-  auto ptr = static_cast<std::shared_ptr<BluCat::StaticModel>*>(obj);
+  auto ptr = static_cast<std::shared_ptr<BluCat::GRA::StaticModel>*>(obj);
 
   ptr->~shared_ptr();
   mrb_free(mrb, ptr);
@@ -37,23 +37,23 @@ const struct mrb_data_type cg_static_model_type = {
 static mrb_value
 cg_cStaticModel_initialize(mrb_state *mrb, mrb_value self)
 {
-  std::shared_ptr<BluCat::StaticMesh> *static_mesh;
-  std::shared_ptr<BluCat::Texture> *texture;
+  std::shared_ptr<BluCat::GRA::StaticMesh> *static_mesh;
+  std::shared_ptr<BluCat::GRA::Texture> *texture;
   std::shared_ptr<glm::vec3> *position;
   std::shared_ptr<glm::quat> *orientation;
-  std::shared_ptr<BluCat::StaticModel> *ptr;
+  std::shared_ptr<BluCat::GRA::StaticModel> *ptr;
 
   mrb_get_args(
     mrb, "dddd", &static_mesh, &cg_static_mesh_type, &texture,
     &cg_texture_type, &position, &cg_vector_3d_type, &orientation,
     &cg_orientation_3d_type);
-  ptr = (std::shared_ptr<BluCat::StaticModel>*)DATA_PTR(self);
+  ptr = (std::shared_ptr<BluCat::GRA::StaticModel>*)DATA_PTR(self);
   if(ptr) mrb_free(mrb, ptr);
-  ptr = (std::shared_ptr<BluCat::StaticModel>*)mrb_malloc(
-    mrb, sizeof(std::shared_ptr<BluCat::StaticModel>));
+  ptr = (std::shared_ptr<BluCat::GRA::StaticModel>*)mrb_malloc(
+    mrb, sizeof(std::shared_ptr<BluCat::GRA::StaticModel>));
 
-  new(ptr)std::shared_ptr<BluCat::StaticModel>(
-    std::make_shared<BluCat::StaticModel>(
+  new(ptr)std::shared_ptr<BluCat::GRA::StaticModel>(
+    std::make_shared<BluCat::GRA::StaticModel>(
       *static_mesh, *texture, *position, *orientation));
 
   mrb_data_init(self, ptr, &cg_static_model_type);
@@ -63,7 +63,7 @@ cg_cStaticModel_initialize(mrb_state *mrb, mrb_value self)
 static mrb_value
 cg_cStaticModel_set_orientation(mrb_state *mrb, mrb_value self)
 {
-  auto ptr = (std::shared_ptr<BluCat::StaticModel>*)DATA_PTR(self);
+  auto ptr = (std::shared_ptr<BluCat::GRA::StaticModel>*)DATA_PTR(self);
   std::shared_ptr<glm::quat> *orientation;
 
   mrb_get_args(mrb, "d", &orientation, &cg_orientation_3d_type);
@@ -75,7 +75,7 @@ cg_cStaticModel_set_orientation(mrb_state *mrb, mrb_value self)
 static mrb_value
 cg_cStaticModel_set_position(mrb_state *mrb, mrb_value self)
 {
-  auto ptr = (std::shared_ptr<BluCat::StaticModel>*)DATA_PTR(self);
+  auto ptr = (std::shared_ptr<BluCat::GRA::StaticModel>*)DATA_PTR(self);
   std::shared_ptr<glm::vec3> *position;
 
   mrb_get_args(mrb, "d", &position, &cg_vector_3d_type);
@@ -87,8 +87,8 @@ cg_cStaticModel_set_position(mrb_state *mrb, mrb_value self)
 static mrb_value
 cg_cStaticModel_set_texture(mrb_state *mrb, mrb_value self)
 {
-  auto ptr = (std::shared_ptr<BluCat::StaticModel>*)DATA_PTR(self);
-  std::shared_ptr<BluCat::Texture> *texture;
+  auto ptr = (std::shared_ptr<BluCat::GRA::StaticModel>*)DATA_PTR(self);
+  std::shared_ptr<BluCat::GRA::Texture> *texture;
 
   mrb_get_args(mrb, "d", &texture, &cg_texture_type);
   (*ptr)->texture = *texture;
@@ -99,10 +99,10 @@ cg_cStaticModel_set_texture(mrb_state *mrb, mrb_value self)
 static mrb_value
 cg_cStaticModel_draw(mrb_state *mrb, mrb_value self)
 {
-  auto ptr = (std::shared_ptr<BluCat::StaticModel>*)DATA_PTR(self);
+  auto ptr = (std::shared_ptr<BluCat::GRA::StaticModel>*)DATA_PTR(self);
 
-  auto &instances = BluCat::core.vk_renderer->static_models_to_draw[
-    BluCat::core.vk_swapchain->current_frame][(*ptr)->static_mesh];
+  auto &instances = BluCat::INT::core.vk_renderer->static_models_to_draw[
+    BluCat::INT::core.vk_swapchain->current_frame][(*ptr)->static_mesh];
   instances.push_back(*ptr);
 
   return self;
diff --git a/src/static_model.hpp b/src/candy_gear/static_model.hpp
index dfb7054..dfb7054 100644
--- a/src/static_model.hpp
+++ b/src/candy_gear/static_model.hpp
diff --git a/src/texture.cpp b/src/candy_gear/texture.cpp
index 0bfac25..355a622 100644
--- a/src/texture.cpp
+++ b/src/candy_gear/texture.cpp
@@ -18,12 +18,12 @@
 
 #include "core.hpp"
 #include "font.hpp"
-#include "blucat/texture.hpp"
+#include "../blu_cat/gra/texture.hpp"
 
 void
 cg_free_texture(mrb_state *mrb, void* obj)
 {
-  auto *ptr = static_cast<std::shared_ptr<BluCat::Texture>*>(obj);
+  auto *ptr = static_cast<std::shared_ptr<BluCat::GRA::Texture>*>(obj);
 
   ptr->~shared_ptr();
   mrb_free(mrb, ptr);
@@ -48,15 +48,15 @@ cg_cTexture_from_image(mrb_state *mrb, mrb_value self)
 {
   struct mrb_value texture = texture_alloc(mrb, self);
   const char *file_path;
-  std::shared_ptr<BluCat::Texture> *ptr;
+  std::shared_ptr<BluCat::GRA::Texture> *ptr;
 
   mrb_get_args(mrb, "z", &file_path);
-  ptr = (std::shared_ptr<BluCat::Texture>*)DATA_PTR(texture);
+  ptr = (std::shared_ptr<BluCat::GRA::Texture>*)DATA_PTR(texture);
   if(ptr) mrb_free(mrb, ptr);
-  ptr = (std::shared_ptr<BluCat::Texture>*)mrb_malloc(
-    mrb, sizeof(std::shared_ptr<BluCat::Texture>));
-  new(ptr)std::shared_ptr<BluCat::Texture>(
-    std::make_shared<BluCat::Texture>(file_path));
+  ptr = (std::shared_ptr<BluCat::GRA::Texture>*)mrb_malloc(
+    mrb, sizeof(std::shared_ptr<BluCat::GRA::Texture>));
+  new(ptr)std::shared_ptr<BluCat::GRA::Texture>(
+    std::make_shared<BluCat::GRA::Texture>(file_path));
 
   mrb_data_init(texture, ptr, &cg_texture_type);
   return texture;
@@ -68,17 +68,17 @@ cg_cTexture_from_text(mrb_state *mrb, mrb_value self)
   const char *text;
   unsigned int width, height;
   struct mrb_value texture = texture_alloc(mrb, self);
-  BluCat::Font *font_ptr;
-  std::shared_ptr<BluCat::Texture> *ptr;
+  BluCat::GRA::Font *font_ptr;
+  std::shared_ptr<BluCat::GRA::Texture> *ptr;
 
   mrb_get_args(mrb, "dz", &font_ptr, &cg_font_type, &text);
 
-  ptr = (std::shared_ptr<BluCat::Texture>*)DATA_PTR(texture);
+  ptr = (std::shared_ptr<BluCat::GRA::Texture>*)DATA_PTR(texture);
   if(ptr) mrb_free(mrb, ptr);
-  ptr = (std::shared_ptr<BluCat::Texture>*)mrb_malloc(
-    mrb, sizeof(std::shared_ptr<BluCat::Texture>));
-  new(ptr)std::shared_ptr<BluCat::Texture>(
-    std::make_shared<BluCat::Texture>(font_ptr, text));
+  ptr = (std::shared_ptr<BluCat::GRA::Texture>*)mrb_malloc(
+    mrb, sizeof(std::shared_ptr<BluCat::GRA::Texture>));
+  new(ptr)std::shared_ptr<BluCat::GRA::Texture>(
+    std::make_shared<BluCat::GRA::Texture>(font_ptr, text));
 
   mrb_data_init(texture, ptr, &cg_texture_type);
   return texture;
@@ -87,14 +87,14 @@ cg_cTexture_from_text(mrb_state *mrb, mrb_value self)
 static mrb_value
 cg_cTexture_width(mrb_state *mrb, mrb_value self)
 {
-  auto ptr = (std::shared_ptr<BluCat::Texture>*)DATA_PTR(self);
+  auto ptr = (std::shared_ptr<BluCat::GRA::Texture>*)DATA_PTR(self);
   return mrb_int_value(mrb, (*ptr)->width);
 }
 
 static mrb_value
 cg_cTexture_height(mrb_state *mrb, mrb_value self)
 {
-  auto ptr = (std::shared_ptr<BluCat::Texture>*)DATA_PTR(self);
+  auto ptr = (std::shared_ptr<BluCat::GRA::Texture>*)DATA_PTR(self);
   return mrb_int_value(mrb, (*ptr)->height);
 }
 
diff --git a/src/texture.hpp b/src/candy_gear/texture.hpp
index 36f23db..cd96026 100644
--- a/src/texture.hpp
+++ b/src/candy_gear/texture.hpp
@@ -18,7 +18,7 @@
 #define CANDY_GEAR_TEXTURE_H 1
 
 #include "core.hpp"
-#include "blucat/command.hpp"
+#include "../blu_cat/com/command.hpp"
 
 extern const struct mrb_data_type cg_texture_type;
 
diff --git a/src/vector_3d.cpp b/src/candy_gear/vector_3d.cpp
index fc5d186..fc5d186 100644
--- a/src/vector_3d.cpp
+++ b/src/candy_gear/vector_3d.cpp
diff --git a/src/vector_3d.hpp b/src/candy_gear/vector_3d.hpp
index 2827813..2827813 100644
--- a/src/vector_3d.hpp
+++ b/src/candy_gear/vector_3d.hpp
diff --git a/src/vector_4d.cpp b/src/candy_gear/vector_4d.cpp
index dedda2f..b44b612 100644
--- a/src/vector_4d.cpp
+++ b/src/candy_gear/vector_4d.cpp
@@ -348,7 +348,7 @@ static mrb_value
 cg_cVector4D_draw_rectangle(mrb_state *mrb, mrb_value self)
 {
   mrb_value view_value;
-  BluCat::View2D *view_2d;
+  BluCat::GRA::View2D *view_2d;
   std::shared_ptr<glm::vec3> *color;
   auto ptr = (std::shared_ptr<glm::vec4>*)DATA_PTR(self);
 
@@ -358,9 +358,9 @@ cg_cVector4D_draw_rectangle(mrb_state *mrb, mrb_value self)
 
   glm::vec4 position(
     (*ptr)->x, (*ptr)->y, (*ptr)->x + (*ptr)->z, (*ptr)->y + (*ptr)->w);
-  BluCat::Rectangle rect{position, (**color)};
+  BluCat::GRA::Rectangle rect{position, (**color)};
   auto &rectangles = view_2d->rectangles_to_draw[
-    BluCat::core.vk_swapchain->current_frame];
+    BluCat::INT::core.vk_swapchain->current_frame];
   rectangles.push_back(rect);
 
   return self;
diff --git a/src/vector_4d.hpp b/src/candy_gear/vector_4d.hpp
index 2797d53..2797d53 100644
--- a/src/vector_4d.hpp
+++ b/src/candy_gear/vector_4d.hpp
diff --git a/src/view_2d.cpp b/src/candy_gear/view_2d.cpp
index 09cbac1..e0dc8a1 100644
--- a/src/view_2d.cpp
+++ b/src/candy_gear/view_2d.cpp
@@ -19,13 +19,13 @@
 #include "sprite.hpp"
 #include "vector_4d.hpp"
 #include "view_3d.hpp"
-#include "blucat/sprite.hpp"
-#include "blucat/view_2d.hpp"
+#include "../blu_cat/gra/sprite.hpp"
+#include "../blu_cat/gra/view_2d.hpp"
 
 void
 cg_free_view_2d(mrb_state *mrb, void* obj)
 {
-  auto ptr = static_cast<std::shared_ptr<BluCat::View2D>*>(obj);
+  auto ptr = static_cast<std::shared_ptr<BluCat::GRA::View2D>*>(obj);
 
   ptr->~shared_ptr();
   mrb_free(mrb, ptr);
@@ -38,35 +38,35 @@ cg_cView2D_initialize(mrb_state *mrb, mrb_value self)
 {
   std::shared_ptr<glm::vec4> *region;
   mrb_float projection_width, projection_height;
-  std::shared_ptr<BluCat::View2D> *ptr;
+  std::shared_ptr<BluCat::GRA::View2D> *ptr;
 
   mrb_get_args(mrb, "dff", &region, &cg_vector_4d_type,
                &projection_width, &projection_height);
-  ptr = (std::shared_ptr<BluCat::View2D>*)DATA_PTR(self);
+  ptr = (std::shared_ptr<BluCat::GRA::View2D>*)DATA_PTR(self);
   if(ptr) mrb_free(mrb, ptr);
-  ptr = (std::shared_ptr<BluCat::View2D>*)mrb_malloc(
-    mrb, sizeof(std::shared_ptr<BluCat::View2D>));
+  ptr = (std::shared_ptr<BluCat::GRA::View2D>*)mrb_malloc(
+    mrb, sizeof(std::shared_ptr<BluCat::GRA::View2D>));
 
-  new(ptr)std::shared_ptr<BluCat::View2D>(
-    std::make_shared<BluCat::View2D>(
+  new(ptr)std::shared_ptr<BluCat::GRA::View2D>(
+    std::make_shared<BluCat::GRA::View2D>(
       *region->get(), projection_width, projection_height));
 
   mrb_data_init(self, ptr, &cg_view_2d_type);
   return self;
 }
 
-BluCat::View2D*
+BluCat::GRA::View2D*
 cg_cView_to_view_2d(mrb_state *mrb, mrb_value view_value)
 {
-  BluCat::View2D* view_2d;
+  BluCat::GRA::View2D* view_2d;
   const mrb_data_type *type = DATA_TYPE(view_value);
 
   if(type == &cg_view_2d_type)
-    view_2d = static_cast<std::shared_ptr<BluCat::View2D>*>(
+    view_2d = static_cast<std::shared_ptr<BluCat::GRA::View2D>*>(
       DATA_PTR(view_value))->get();
   else if (type == &cg_view_3d_type)
-    view_2d = static_cast<BluCat::View2D*>(
-      static_cast<std::shared_ptr<BluCat::View3D>*>(
+    view_2d = static_cast<BluCat::GRA::View2D*>(
+      static_cast<std::shared_ptr<BluCat::GRA::View3D>*>(
         DATA_PTR(view_value))->get());
   else
     mrb_raisef(
diff --git a/src/view_2d.hpp b/src/candy_gear/view_2d.hpp
index a18937e..9b742a0 100644
--- a/src/view_2d.hpp
+++ b/src/candy_gear/view_2d.hpp
@@ -23,8 +23,8 @@ extern const struct mrb_data_type cg_view_2d_type;
 
 // Receives a mrb_value that points to a View2D or a View3D and returns a
 // pointer to View2D. If the mrb_value points to a View3D, the view will be
-// cast to a BluCat::View2D.
-BluCat::View2D*
+// cast to a BluCat::GRA::View2D.
+BluCat::GRA::View2D*
 cg_cView_to_view_2d(mrb_state *mrb, mrb_value view_value);
 
 void
diff --git a/src/view_3d.cpp b/src/candy_gear/view_3d.cpp
index ddaa3eb..b829cca 100644
--- a/src/view_3d.cpp
+++ b/src/candy_gear/view_3d.cpp
@@ -20,13 +20,13 @@
 #include "orientation_3d.hpp"
 #include "vector_3d.hpp"
 #include "vector_4d.hpp"
-#include "blucat/sprite.hpp"
-#include "blucat/view_3d.hpp"
+#include "../blu_cat/gra/sprite.hpp"
+#include "../blu_cat/gra/view_3d.hpp"
 
 void
 cg_free_view_3d(mrb_state *mrb, void* obj)
 {
-  auto ptr = static_cast<std::shared_ptr<BluCat::View3D>*>(obj);
+  auto ptr = static_cast<std::shared_ptr<BluCat::GRA::View3D>*>(obj);
 
   ptr->~shared_ptr();
   mrb_free(mrb, ptr);
@@ -39,17 +39,17 @@ cg_cView3D_initialize(mrb_state *mrb, mrb_value self)
 {
   std::shared_ptr<glm::vec4> *region;
   mrb_float projection_width, projection_height;
-  std::shared_ptr<BluCat::View3D> *ptr;
+  std::shared_ptr<BluCat::GRA::View3D> *ptr;
 
   mrb_get_args(mrb, "dff", &region, &cg_vector_4d_type,
                &projection_width, &projection_height);
-  ptr = (std::shared_ptr<BluCat::View3D>*)DATA_PTR(self);
+  ptr = (std::shared_ptr<BluCat::GRA::View3D>*)DATA_PTR(self);
   if(ptr) mrb_free(mrb, ptr);
-  ptr = (std::shared_ptr<BluCat::View3D>*)mrb_malloc(
-    mrb, sizeof(std::shared_ptr<BluCat::View3D>));
+  ptr = (std::shared_ptr<BluCat::GRA::View3D>*)mrb_malloc(
+    mrb, sizeof(std::shared_ptr<BluCat::GRA::View3D>));
 
-  new(ptr)std::shared_ptr<BluCat::View3D>(
-    std::make_shared<BluCat::View3D>(
+  new(ptr)std::shared_ptr<BluCat::GRA::View3D>(
+    std::make_shared<BluCat::GRA::View3D>(
       *region->get(), projection_width, projection_height));
 
   mrb_data_init(self, ptr, &cg_view_3d_type);
@@ -60,7 +60,7 @@ static mrb_value
 cg_cView3D_set_camera_position(mrb_state *mrb, mrb_value self)
 {
   std::shared_ptr<glm::vec3> *camera_position;
-  auto ptr = (std::shared_ptr<BluCat::View3D>*)DATA_PTR(self);
+  auto ptr = (std::shared_ptr<BluCat::GRA::View3D>*)DATA_PTR(self);
 
   mrb_get_args(mrb, "d", &camera_position, &cg_vector_3d_type);
   (*ptr)->camera_position = (*camera_position);
@@ -72,7 +72,7 @@ static mrb_value
 cg_cView3D_set_camera_orientation(mrb_state *mrb, mrb_value self)
 {
   std::shared_ptr<glm::quat> *camera_orientation;
-  auto ptr = (std::shared_ptr<BluCat::View3D>*)DATA_PTR(self);
+  auto ptr = (std::shared_ptr<BluCat::GRA::View3D>*)DATA_PTR(self);
 
   mrb_get_args(mrb, "d", &camera_orientation, &cg_orientation_3d_type);
   (*ptr)->camera_orientation = (*camera_orientation);
@@ -83,7 +83,7 @@ cg_cView3D_set_camera_orientation(mrb_state *mrb, mrb_value self)
 static mrb_value
 cg_cView3D_get_field_of_view(mrb_state *mrb, mrb_value self)
 {
-  auto ptr = (std::shared_ptr<BluCat::View3D>*)DATA_PTR(self);
+  auto ptr = (std::shared_ptr<BluCat::GRA::View3D>*)DATA_PTR(self);
 
   return mrb_float_value(mrb, (*ptr)->field_of_view);
 
@@ -94,7 +94,7 @@ static mrb_value
 cg_cView3D_set_field_of_view(mrb_state *mrb, mrb_value self)
 {
   mrb_float fov;
-  auto ptr = (std::shared_ptr<BluCat::View3D>*)DATA_PTR(self);
+  auto ptr = (std::shared_ptr<BluCat::GRA::View3D>*)DATA_PTR(self);
 
   mrb_get_args(mrb, "f", &fov);
   (*ptr)->field_of_view = fov;
diff --git a/src/view_3d.hpp b/src/candy_gear/view_3d.hpp
index 22aa084..22aa084 100644
--- a/src/view_3d.hpp
+++ b/src/candy_gear/view_3d.hpp