Acid is an open-source, cross-platform game engine written in modern C++17 with a focus on modularity and simplicity. Features are broken down into modules, modules can be loaded or unloaded from Acid with ease. Acid uses an Entity Component System that breaks entity features between serializable Components.

Vulkan is used as the only rendering API, as a result, Vulkan functions can be used directly in games, but should be avoided. Metal is supported through MoltenVK, eventually, DirectX will be supported in a similar way.

Acid is licensed under the MIT licence and is open to contributions, read Compiling to get started with development.

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Features

This is a list of current features in Acid:

Multiplatform (Windows, Linux, MacOS, 32bit and 64bit)
Multithreaded command buffers and thread safety
On the fly GLSL to SPIR-V compilation and reflection
Graphics and compute pipelines
Deferred rendering (PBR, Simple)
Networking (HTTP, FTP, UDP, TCP)
Serialization (JSON, YAML, XML)
Resource management
Event delegate callbacks
Bullet physics
Entity component system
Particle effect systems
File path searching, and packaging
GUI and SDF font rendering
Audio systems (OGG, WAV)
Shadow mapping
Post effects (Lensflare, Glow, Blur, SSAO, ...)
Model file loading (OBJ)
Animations loading (COLLADA)
Image file loading (JPG, PNG, TGA, BMP, PSD, GIF, HDR, PIC)

Dependencies

Acid uses the following libraries:

Vulkan - Vulkan interface
Glslang - Shader compiling
GLFW - Window creation
OpenAL - Audio interface
Bullet3 - Physics integration
PhysFS - Archive file access
STB - Texture and OGG loading
FastNoise - Noise generation
Freetype2 - Font handling in text objects

Code Snippets

// Imports a 2D texture using nearest filtering.
auto guiBlack = Texture::Create("Guis/Black.png", VK_FILTER_NEAREST);

// Imports a 3D cubemap (face names defined in Cubemap.cpp).
auto skyboxSnowy = Cubemap::Create("Objects/SkyboxSnowy", ".png");

// Imports a OBJ model.
auto dragon = ModelObj::Create("Objects/Testing/ModelDragon.obj");

// Creates a sphere model with 20 latitude and longitude bands with a radius of 1.
auto sphere = ModelSphere::Create(20, 20, 1.0f);

// Plays a 3D sound (sound buffer resource internally managed), at (10, 0, 0), at half volume.
auto jump = Sound("Sounds/Jump.ogg", Transform(10.0f * Vector3f::Right), Audio::Type::Effect, false, true, 0.5f);

// Loads a entity from a prefab file.
auto playerObject = GetStructure()->CreateEntity("Objects/Player/Player.json", Transform::Identity);

// Creates a entity.
auto sphere = GetStructure()->CreateEntity(Transform(Vector3f(6.7f, 6.7f, -8.0f), Vector3f::Zero, 3.0f));
sphere->AddComponent<Mesh>(ShapeSphere::Create(20, 20, 1.0f)); // This will used the sphere buffers created earlier.
sphere->AddComponent<ShapeSphere>(); // Multiple shape components can be added to a single rigidbody.
sphere->AddComponent<Rigidbody>(2.0f); // Will be created weighing 2 units, this will find all shapes attached.
sphere->AddComponent<MaterialDefault>(Colour::White, Texture::Create("Objects/Testing/Albedo.png"), 0.0f, 0.5f,
    Texture::Create("Objects/Testing/Material.png"), Texture::Create("Objects/Testing/Normal.png"));
sphere->AddComponent<MeshRender>(); // A mesh renderer will render the material attached.

// Vector maths.
Vector2f a(3.0f, -7.2f);
Vector2f b(-1.74f, 15.4f);
Vector2f c = a * b;
float dist = a.Distance(b);

// Split a string by spaces.
std::string stringSource = "Hello world!";
std::vector<std::string> stringSplit = String::Split(stringSource, " ");

// Will run a lambda on window resize.
Window::Get()->OnSize() += [](Vector2ui size){
	Log::Out("Hello world: %s\n", size.ToString().c_str());
};

Screenshots

Compiling

All platforms depend on CMake, 3.11 or higher, to generate IDE/make files.

Cmake options (default ON):

BUILD_TESTS
ACID_INSTALL_EXAMPLES
ACID_INSTALL_RESOURCES

If you installed Acid using only system libs, then find_package(Acid) will work from Cmake. Versioning is also supported.
When using find_package(Acid) the imported target Acid::Acid will be created.
The ACID_RESOURCES_DIR variable will also be available, which will point to the on-disk location of Acid/Resources (if installed).

Vulkan SDK, OpenAL, and OpenAL SDK are required to develop and run Acid.

Make sure you have environment variables VULKAN_SDK and OPENALDIR set to the paths you have Vulkan and OpenAL installed into.

Ensure you are using a compiler with full C++17 support, on Windows it is recommended that you use MSVC or MinGW w64.

If using Visual Studio it must be 2015 or later. Use the Visual Studio installer and select both "Desktop development with C++" and "Windows SDK" if they are not already installed. Then on Visual Studio Acid can be opened as a CMake workspace folder.

On Linux Acid requires xorg-dev, libopenal1, and libvulkan1 to be installed. Read about how to setup Vulkan on Linux so a Vulkan SDK is found.

Setup on MacOS is similar to the setup on Linux, a compiler that supports C++17 is required, such as XCode 10.0.

Contributing

You can contribute to Acid in any way you want, we are always looking for help. You can learn about Acids code style from the Documents/GUIDELINES.md.