C++ Game engine for top-down roguelikes. It also includes an example.

qdu-engine relies on third-party libraries, these can be found under the thirdParty folder.

• ImGui for debug GUI.
• GLFW to create and manage windows and user inputs.
• glad to load OpenGL functions.
• glm for lineal algebra.
• stb_image to load images from disk.
• dr_wav to load .wav sound files from disk.
• OpenAL-Soft to manage audio.

Building the engine requires CMake 3.20+ and OpenGL4.5.

• Clone the repository.
• Build the game engine with Visual Studio 17 2022:
  • mkdir build
  • cd build
  • cmake ..
  • Open the solution: qdu-engine.sln
  • Build the solution in Release x64 mode.
• In a separate directory, build OpenAl soft according to the instructions in: https://github.com/kcat/openal-soft

Building in debug mode allows to access a visual debugger with F5. This requires to build the first solution in Debug x64 mode instead.

• From the build folder, go to and execute the demo:
  • cd Examples/Release
  • Demo.exe
• Add the result of building OpenAL soft to the same directory as Demo.exe (will result in missing .dll file otherwise).

For debug mode, replace Release with Debug.

A new application can be created with CMake by including the engine as a subdirectory of the project. The project structure should be as follows:

• A folder called qdu-engine which contains the repository files.
• A CMakeLists.txt file similar to the one presented below, where MyGame is the name of the project, main.cpp the main file (should include the <QDUEngine.hpp> header), and MyGameDir the root folder of the project.
• Additional headers can be specified after main.cpp.

set(CMAKE_LEGACY_CYGWIN_WIN32 OFF)
get_filename_component(CODE_ROOT ${CMAKE_CURRENT_SOURCE_DIR} DIRECTORY)
cmake_minimum_required(VERSION 3.20)
project(MyGame C CXX)
add_subdirectory(${CODE_ROOT}/MyGameDir/qdu-engine)
link_directories(${CODE_ROOT}/MyGameDir/qdu-engine)
add_executable(MyGame main.cpp)
set_property(TARGET MyGame PROPERTY CXX_STANDARD 20)
target_link_libraries(MyGame PRIVATE QDUEngine)
target_include_directories(MyGame PRIVATE ${QDU_INCLUDE_DIRECTORY} ${THIRD_PARTY_INCLUDE_DIRECTORIES})

Note that executables created this way will also require the OpenAL soft files built before.

The engine seeks to provide utilities according to the Entity-Component-System architecture. What follows is a brief description of it's principal classes.

• Application: Any application created should extend this class, it contains a scene where to put game objects. It also controls global settings, such as key bindings, window size, and temporary directories. Methods to override:

  • userStart() for initialization.
  • onTransition() to handle scene changes.

• GameObject: Entity in ECS. Can have any (or none) of the following components:

  • InputComponent: Allows to handle actions. Methods to override:

    • onAction() to handle keyboard keys and joysticks.
    • onCursorAction() to handle cursor clicks.
    • onUpdate() to handle actions dictated by time.

  • AudioComponent: Allows to play audio from WAV files.

  • VisualComponent: Allows to represent the object in 3D.

• Scene: Contains the active GameObjects. Can be switch, stored, and loaded from JSON files.

• NavigationMesh: Allows to handle pathfinding inside a Scene with the use of A*. It can be loaded from a OBJ file (requires triangular faces).

For more information, review the demo.cpp example inside the examples folder.