diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 395906c8..6d6c9c9b 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -12,3 +12,4 @@ jobs:
     uses: ./.github/workflows/cmake.yml
     with:
       build_type: Release
+      run_tests: true
diff --git a/.github/workflows/cmake.yml b/.github/workflows/cmake.yml
index dce8c120..343d35e7 100644
--- a/.github/workflows/cmake.yml
+++ b/.github/workflows/cmake.yml
@@ -12,6 +12,10 @@ on:
         description: Should upload artifacts or not
         type: boolean
         default: false
+      run_tests:
+        description: Run CTest after project build
+        type: boolean
+        default: false
 
 jobs:
   build:
@@ -35,7 +39,7 @@ jobs:
     #   make && make install INSTALL_INC=/usr/include/lua
       run: |
           sudo apt-get update
-          sudo apt-get install libglfw3-dev libglfw3 libglew-dev libglm-dev libpng-dev libopenal-dev libluajit-5.1-dev libvorbis-dev
+          sudo apt-get install libglfw3-dev libglfw3 libglew-dev libglm-dev libpng-dev libopenal-dev libluajit-5.1-dev libvorbis-dev libgtest-dev
           # fix luajit paths
           sudo ln -s /usr/lib/x86_64-linux-gnu/libluajit-5.1.a /usr/lib/x86_64-linux-gnu/liblua-5.1.a
           sudo ln -s /usr/include/luajit-2.1 /usr/include/lua
@@ -52,14 +56,16 @@ jobs:
       # make.
       #
       # See https://cmake.org/cmake/help/latest/variable/CMAKE_BUILD_TYPE.html?highlight=cmake_build_type
-      run: cmake -B ${{github.workspace}}/build -DCMAKE_BUILD_TYPE=${{inputs.build_type}}
+      run: cmake -B ${{github.workspace}}/build -DCMAKE_BUILD_TYPE=${{inputs.build_type}} -DVOXELENGINE_BUILD_TESTS=ON
 
     - name: Build
       # Build your program with the given configuration
       run: |
         cmake --build ${{github.workspace}}/build --config ${{inputs.build_type}}
         mv ${{github.workspace}}/build/VoxelEngine VoxelEngine
-
+    - name: Run tests
+      if: ${{ inputs.run_tests }}
+      run: ctest --test-dir ${{github.workspace}}/build
     - name: Upload artifacts
       if: ${{ inputs.upload_artifacts }}
       uses: actions/upload-artifact@v4
diff --git a/.github/workflows/macos.yml b/.github/workflows/macos.yml
index a477d3c0..1f9675ca 100644
--- a/.github/workflows/macos.yml
+++ b/.github/workflows/macos.yml
@@ -17,7 +17,7 @@ jobs:
 
       - name: Install dependencies from brew
         run: |
-          brew install glfw3 glew libpng openal-soft luajit libvorbis skypjack/entt/entt
+          brew install glfw3 glew libpng openal-soft luajit libvorbis skypjack/entt/entt googletest
 
       - name: Install specific version of GLM
         run: |
@@ -25,7 +25,7 @@ jobs:
           brew install --formula glm.rb
 
       - name: Configure
-        run: cmake -S . -B build -DCMAKE_BUILD_TYPE=Release -DVOXELENGINE_BUILD_APPDIR=1
+        run: cmake -S . -B build -DCMAKE_BUILD_TYPE=Release -DVOXELENGINE_BUILD_TESTS=ON -DVOXELENGINE_BUILD_APPDIR=1
 
       - name: Build
         run: cmake --build build -t install
@@ -36,6 +36,9 @@ jobs:
       - name: Fix dylibs
         run: ./dev/fix_dylibs.sh VoxelEngine Release build
 
+      - name: Run tests
+        run: ctest --test-dir build
+
       - name: Create DMG
         run: |
           mkdir VoxelEngineDmgContent
diff --git a/.github/workflows/windows.yml b/.github/workflows/windows.yml
index 46fe7122..6af90077 100644
--- a/.github/workflows/windows.yml
+++ b/.github/workflows/windows.yml
@@ -32,16 +32,17 @@ jobs:
         run: |
           mkdir build
           cd build
-          cmake -DCMAKE_BUILD_TYPE=Release -DVOXELENGINE_BUILD_WINDOWS_VCPKG=ON ..
+          cmake -DCMAKE_BUILD_TYPE=Release -DVOXELENGINE_BUILD_WINDOWS_VCPKG=ON -DVOXELENGINE_BUILD_TESTS=ON ..
           Remove-Item -Path CMakeFiles -Recurse -Force
-          cmake -DCMAKE_BUILD_TYPE=Release -DVOXELENGINE_BUILD_WINDOWS_VCPKG=ON ..
+          cmake -DCMAKE_BUILD_TYPE=Release -DVOXELENGINE_BUILD_WINDOWS_VCPKG=ON -DVOXELENGINE_BUILD_TESTS=ON ..
           cmake --build . --config Release
       - name: Package for Windows
         run: |
           mkdir packaged
           cp -r build/* packaged/
         working-directory: ${{ github.workspace }}
-
+      - name: Run tests
+        run: ctest --test-dir build
       - uses: actions/upload-artifact@v2
         with:
           name: Windows-Build
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 579ee11b..2ec82dca 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -7,31 +7,16 @@ cmake_minimum_required(VERSION 3.15)
 project(VoxelEngine)
 
 option(VOXELENGINE_BUILD_APPDIR OFF)
+option(VOXELENGINE_BUILD_TESTS OFF)
 
 set(CMAKE_CXX_STANDARD 17)
 
-file(GLOB_RECURSE HEADERS ${CMAKE_CURRENT_SOURCE_DIR}/src/*.hpp)
-file(GLOB_RECURSE SOURCES ${CMAKE_CURRENT_SOURCE_DIR}/src/*.cpp)
-
-add_executable(${PROJECT_NAME} ${SOURCES})
+add_subdirectory(src)
+add_executable(${PROJECT_NAME} src/voxel_engine.cpp)
 target_include_directories(${PROJECT_NAME} PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/src)
 
 if(VOXELENGINE_BUILD_APPDIR)
-  file(MAKE_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/AppDir/usr/bin)
-  file(MAKE_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/AppDir/usr/lib)
-  file(MAKE_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/AppDir/usr/share/icons/hicolor/256x256)
-  file(MAKE_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/AppDir/usr/share/applications)
-  file(MAKE_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/AppDir/usr/share/VoxelEngine)
-  file(COPY ${CMAKE_CURRENT_SOURCE_DIR}/res DESTINATION ${CMAKE_CURRENT_SOURCE_DIR}/AppDir/usr/share/VoxelEngine)
-  file(COPY ${CMAKE_CURRENT_SOURCE_DIR}/dev/VoxelEngine.png DESTINATION ${CMAKE_CURRENT_SOURCE_DIR}/AppDir/usr/share/icons/hicolor/256x256)
-  file(COPY ${CMAKE_CURRENT_SOURCE_DIR}/dev/VoxelEngine.png DESTINATION ${CMAKE_CURRENT_SOURCE_DIR}/AppDir)
-  file(COPY ${CMAKE_CURRENT_SOURCE_DIR}/dev/VoxelEngine.png DESTINATION ${CMAKE_CURRENT_SOURCE_DIR}/AppDir/.dirIcon)
-  file(COPY ${CMAKE_CURRENT_SOURCE_DIR}/dev/VoxelEngine.desktop DESTINATION ${CMAKE_CURRENT_SOURCE_DIR}/AppDir/usr/share/applications)
-  file(COPY ${CMAKE_CURRENT_SOURCE_DIR}/dev/VoxelEngine.desktop DESTINATION ${CMAKE_CURRENT_SOURCE_DIR}/AppDir/)
-  set(CMAKE_ARCHIVE_OUTPUT_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/AppDir/usr/lib)
-  set(CMAKE_LIBRARY_OUTPUT_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/AppDir/usr/lib)
-  set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/AppDir/usr/bin)
-  install(TARGETS VoxelEngine DESTINATION ${CMAKE_CURRENT_SOURCE_DIR}/AppDir/usr/bin)
+    include(${CMAKE_CURRENT_SOURCE_DIR}/dev/cmake/BuildAppdir.cmake)
 endif()
 
 if(MSVC)
@@ -81,67 +66,15 @@ if(VOXELENGINE_BUILD_WINDOWS_VCPKG AND WIN32)
   endforeach()
 endif()
 
-find_package(OpenGL REQUIRED)
-find_package(GLEW REQUIRED)
-find_package(OpenAL REQUIRED)
-find_package(ZLIB REQUIRED)
-if (NOT APPLE)
-    find_package(EnTT REQUIRED)
-endif()
-
-if (WIN32)
-    if(VOXELENGINE_BUILD_WINDOWS_VCPKG)
-      set(LUA_LIBRARIES "${CMAKE_CURRENT_SOURCE_DIR}/vcpkg/packages/luajit_x64-windows/lib/lua51.lib")
-      set(LUA_INCLUDE_DIR "${CMAKE_CURRENT_SOURCE_DIR}/vcpkg/packages/luajit_x64-windows/include/luajit")
-      find_package(glfw3 REQUIRED)
-      find_package(spng REQUIRED)
-      find_package(glm REQUIRED)
-      find_package(vorbis REQUIRED)
-      set(PNGLIB spng::spng)
-      set(VORBISLIB Vorbis::vorbis Vorbis::vorbisfile)
-    else()
-      find_package(Lua REQUIRED)
-      set(PNGLIB spng)
-      set(VORBISLIB vorbis vorbisfile) # not tested
-      add_subdirectory(${CMAKE_CURRENT_SOURCE_DIR}/libs/glfw)
-    endif()
-elseif(APPLE)
-    find_package(PkgConfig)
-    pkg_check_modules(LUAJIT REQUIRED luajit)
-    pkg_check_modules(VORBIS REQUIRED vorbis vorbisfile)
-    set(LUA_INCLUDE_DIR "/opt/homebrew/include/luajit-2.1")
-    set(LUA_LIBRARIES "/opt/homebrew/lib/libluajit-5.1.a")
-    message(STATUS "LUA Libraries: ${LUA_LIBRARIES}")
-    message(STATUS "LUA Include Dir: ${LUA_INCLUDE_DIR}")
-    find_package(PNG REQUIRED)
-    set(PNGLIB PNG::PNG)
-    set(VORBISLIB ${VORBIS_LDFLAGS})
-    message(STATUS "Vorbis Lib: ${VORBIS_LDFLAGS}")
-else()
-    find_package(PkgConfig)
-    pkg_check_modules(LUAJIT REQUIRED luajit)
-    pkg_check_modules(VORBIS REQUIRED vorbis vorbisfile)
-    set(LUA_LIBRARIES ${LUAJIT_LIBRARIES})
-    set(LUA_INCLUDE_DIR ${LUAJIT_INCLUDE_DIRS})
-    find_package(PNG REQUIRED)
-    set(PNGLIB PNG::PNG)
-    set(VORBISLIB ${VORBIS_LDFLAGS})
-endif()
-
-set(LIBS "")
-
-if(UNIX)
-    find_package(glfw3 3.3 REQUIRED)
-    find_package(Threads REQUIRED)
-    set(LIBS ${LIBS} Threads::Threads)
-endif()
-
 if (CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
     set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -no-pie -lstdc++fs")
 endif()
 
-include_directories(${LUA_INCLUDE_DIR})
-target_link_libraries(${PROJECT_NAME} ${LIBS} glfw OpenGL::GL ${OPENAL_LIBRARY} GLEW::GLEW ZLIB::ZLIB ${VORBISLIB} ${PNGLIB} ${LUA_LIBRARIES} ${CMAKE_DL_LIBS})
+target_link_libraries(${PROJECT_NAME} VoxelEngineSrc ${CMAKE_DL_LIBS})
 
 file(COPY ${CMAKE_CURRENT_SOURCE_DIR}/res DESTINATION ${CMAKE_CURRENT_BINARY_DIR})
 
+if (VOXELENGINE_BUILD_TESTS)
+    enable_testing()
+    add_subdirectory(test)
+endif()
diff --git a/dev/cmake/BuildAppdir.cmake b/dev/cmake/BuildAppdir.cmake
new file mode 100644
index 00000000..245b2925
--- /dev/null
+++ b/dev/cmake/BuildAppdir.cmake
@@ -0,0 +1,15 @@
+file(MAKE_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/AppDir/usr/bin)
+file(MAKE_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/AppDir/usr/lib)
+file(MAKE_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/AppDir/usr/share/icons/hicolor/256x256)
+file(MAKE_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/AppDir/usr/share/applications)
+file(MAKE_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/AppDir/usr/share/VoxelEngine)
+file(COPY ${CMAKE_CURRENT_SOURCE_DIR}/res DESTINATION ${CMAKE_CURRENT_SOURCE_DIR}/AppDir/usr/share/VoxelEngine)
+file(COPY ${CMAKE_CURRENT_SOURCE_DIR}/dev/VoxelEngine.png DESTINATION ${CMAKE_CURRENT_SOURCE_DIR}/AppDir/usr/share/icons/hicolor/256x256)
+file(COPY ${CMAKE_CURRENT_SOURCE_DIR}/dev/VoxelEngine.png DESTINATION ${CMAKE_CURRENT_SOURCE_DIR}/AppDir)
+file(COPY ${CMAKE_CURRENT_SOURCE_DIR}/dev/VoxelEngine.png DESTINATION ${CMAKE_CURRENT_SOURCE_DIR}/AppDir/.dirIcon)
+file(COPY ${CMAKE_CURRENT_SOURCE_DIR}/dev/VoxelEngine.desktop DESTINATION ${CMAKE_CURRENT_SOURCE_DIR}/AppDir/usr/share/applications)
+file(COPY ${CMAKE_CURRENT_SOURCE_DIR}/dev/VoxelEngine.desktop DESTINATION ${CMAKE_CURRENT_SOURCE_DIR}/AppDir/)
+set(CMAKE_ARCHIVE_OUTPUT_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/AppDir/usr/lib)
+set(CMAKE_LIBRARY_OUTPUT_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/AppDir/usr/lib)
+set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/AppDir/usr/bin)
+install(TARGETS VoxelEngine DESTINATION ${CMAKE_CURRENT_SOURCE_DIR}/AppDir/usr/bin)
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
new file mode 100644
index 00000000..8cd21fbd
--- /dev/null
+++ b/src/CMakeLists.txt
@@ -0,0 +1,70 @@
+project(VoxelEngineSrc)
+
+set(CMAKE_CXX_STANDARD 17)
+
+file(GLOB_RECURSE HEADERS ${CMAKE_CURRENT_SOURCE_DIR}/*.hpp)
+file(GLOB_RECURSE SOURCES ${CMAKE_CURRENT_SOURCE_DIR}/*.cpp)
+list(REMOVE_ITEM SOURCES ${CMAKE_CURRENT_SOURCE_DIR}/voxel_engine.cpp)
+
+add_library(${PROJECT_NAME} ${SOURCES} ${HEADERS})
+
+option(VOXELENGINE_BUILD_WINDOWS_VCPKG ON)
+
+find_package(OpenGL REQUIRED)
+find_package(GLEW REQUIRED)
+find_package(OpenAL REQUIRED)
+find_package(ZLIB REQUIRED)
+if (NOT APPLE)
+    find_package(EnTT REQUIRED)
+endif()
+
+if (WIN32)
+    if(VOXELENGINE_BUILD_WINDOWS_VCPKG)
+      set(LUA_LIBRARIES "${CMAKE_CURRENT_SOURCE_DIR}/../vcpkg/packages/luajit_x64-windows/lib/lua51.lib")
+      set(LUA_INCLUDE_DIR "${CMAKE_CURRENT_SOURCE_DIR}/../vcpkg/packages/luajit_x64-windows/include/luajit")
+      find_package(glfw3 REQUIRED)
+      find_package(spng REQUIRED)
+      find_package(glm REQUIRED)
+      find_package(vorbis REQUIRED)
+      set(PNGLIB spng::spng)
+      set(VORBISLIB Vorbis::vorbis Vorbis::vorbisfile)
+    else()
+      find_package(Lua REQUIRED)
+      set(PNGLIB spng)
+      set(VORBISLIB vorbis vorbisfile) # not tested
+      add_subdirectory(${CMAKE_CURRENT_SOURCE_DIR}/libs/glfw)
+    endif()
+elseif(APPLE)
+    find_package(PkgConfig)
+    pkg_check_modules(LUAJIT REQUIRED luajit)
+    pkg_check_modules(VORBIS REQUIRED vorbis vorbisfile)
+    set(LUA_INCLUDE_DIR "/opt/homebrew/include/luajit-2.1")
+    set(LUA_LIBRARIES "/opt/homebrew/lib/libluajit-5.1.a")
+    message(STATUS "LUA Libraries: ${LUA_LIBRARIES}")
+    message(STATUS "LUA Include Dir: ${LUA_INCLUDE_DIR}")
+    find_package(PNG REQUIRED)
+    set(PNGLIB PNG::PNG)
+    set(VORBISLIB ${VORBIS_LDFLAGS})
+    message(STATUS "Vorbis Lib: ${VORBIS_LDFLAGS}")
+else()
+    find_package(PkgConfig)
+    pkg_check_modules(LUAJIT REQUIRED luajit)
+    pkg_check_modules(VORBIS REQUIRED vorbis vorbisfile)
+    set(LUA_LIBRARIES ${LUAJIT_LIBRARIES})
+    set(LUA_INCLUDE_DIR ${LUAJIT_INCLUDE_DIRS})
+    find_package(PNG REQUIRED)
+    set(PNGLIB PNG::PNG)
+    set(VORBISLIB ${VORBIS_LDFLAGS})
+endif()
+
+set(LIBS "")
+
+if(UNIX)
+    find_package(glfw3 3.3 REQUIRED)
+    find_package(Threads REQUIRED)
+    set(LIBS ${LIBS} Threads::Threads)
+endif()
+
+include_directories(${LUA_INCLUDE_DIR})
+target_include_directories(${PROJECT_NAME} PRIVATE ${CMAKE_CURRENT_SOURCE_DIR})
+target_link_libraries(${PROJECT_NAME} ${LIBS} glfw OpenGL::GL ${OPENAL_LIBRARY} GLEW::GLEW ZLIB::ZLIB ${VORBISLIB} ${PNGLIB} ${LUA_LIBRARIES} ${CMAKE_DL_LIBS})
diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
new file mode 100644
index 00000000..cbe038a6
--- /dev/null
+++ b/test/CMakeLists.txt
@@ -0,0 +1,19 @@
+project(VoxelEngineTest)
+
+set(CMAKE_CXX_STANDARD 17)
+
+file(GLOB_RECURSE SOURCES ${CMAKE_CURRENT_SOURCE_DIR}/*.cpp)
+
+find_package(GTest)
+
+add_executable(${PROJECT_NAME} ${SOURCES})
+
+target_include_directories(${PROJECT_NAME} PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/../src)
+target_link_libraries(
+  ${PROJECT_NAME}
+  VoxelEngineSrc
+  GTest::gtest_main
+)
+
+include(GoogleTest)
+gtest_discover_tests(${PROJECT_NAME})
diff --git a/test/coders/rle.cpp b/test/coders/rle.cpp
new file mode 100644
index 00000000..c93a034a
--- /dev/null
+++ b/test/coders/rle.cpp
@@ -0,0 +1,48 @@
+#include <gtest/gtest.h>
+
+#include "typedefs.hpp"
+#include "coders/rle.hpp"
+
+TEST(RLE, EncodeDecode) {
+    const int initial_size = 50'000;
+    uint8_t initial[initial_size];
+    uint8_t next = rand();
+    for (int i = 0; i < initial_size; i++) {
+        initial[i] = next;
+        if (rand() % 13 == 0) {
+            next = rand();
+        }
+    }
+    uint8_t encoded[initial_size * 2];
+    auto encoded_size = rle::encode(initial, initial_size, encoded);
+    uint8_t decoded[initial_size * 2];
+    auto decoded_size = rle::decode(encoded, encoded_size, decoded);
+    
+    EXPECT_EQ(decoded_size, initial_size);
+
+    for (int i = 0; i < decoded_size; i++) {
+        EXPECT_EQ(decoded[i], initial[i]);
+    }
+}
+
+TEST(ExtRLE, EncodeDecode) {
+    const int initial_size = 50'000;
+    uint8_t initial[initial_size];
+    uint8_t next = rand();
+    for (int i = 0; i < initial_size; i++) {
+        initial[i] = next;
+        if (rand() % 13 == 0) {
+            next = rand();
+        }
+    }
+    uint8_t encoded[initial_size * 2];
+    auto encoded_size = extrle::encode(initial, initial_size, encoded);
+    uint8_t decoded[initial_size * 2];
+    auto decoded_size = extrle::decode(encoded, encoded_size, decoded);
+    
+    EXPECT_EQ(decoded_size, initial_size);
+
+    for (int i = 0; i < decoded_size; i++) {
+        EXPECT_EQ(decoded[i], initial[i]);
+    }
+}
diff --git a/vcpkg.json b/vcpkg.json
index b53f9d40..05fe48e2 100644
--- a/vcpkg.json
+++ b/vcpkg.json
@@ -11,6 +11,7 @@
       "zlib",
       "luajit",
       "libvorbis",
-      "entt"
+      "entt",
+      "gtest"
     ]
   }