# Kaliber

A simple, cross-platform 2D game engine with OpenGL and Vulkan renderers.
Supports Linux, Windows and Android platforms.
This is a personal hobby project. I've published a little game on
[Google Play](https://play.google.com/store/apps/details?id=com.woom.game)
based on this engine. Full game code and assets are included in this repository.

## Pre-requisites:

GN build system is required for all platforms:\
https://gn.googlesource.com/gn/

## Building from the command-line:

### All platforms except Android:
#### Setup:
Generate build files for Ninja in release and debug modes.
```text
gn gen out/release
gn gen --args='is_debug=true' out/debug
```
#### Building and running:
Build all games in release mode and run "hello_world".
```text
ninja -C out/release
./out/release/hello_world
```
Build only "demo" in debug mode and run.
```text
ninja -C out/debug demo
./out/debug/demo
```
### Android:
Build the default game ("hello_world") in debug mode for all ABIs and install.
GN will be run by Gradle so no setup is required. Both Linux and Windows are
supported as host platforms. The Gradle project can also be
opened in Android Studio.
```text
cd build/android
./gradlew :app:installDebug
```
Build in release mode. The generated APK must be signed before installing.
```text
./gradlew :app:assembleRelease
```
Build configuration can be changed via project properties. The following command
will build "demo" in debug mode for x86_64 ABI and install. "targetArchs"
property can be set to any combination of Arm7, Arm8, X86_64, X86. Location of
gn and ninja executables can also be specified via "gn" and "ninja" properties.
```text
./gradlew :app:installDebug -PtargetArchs="X86_64" -PtargetGame="demo"
```
### Generate Visual Studio solution:
```text
gn.exe gen --args="is_debug=true" --ide=vs2022 out\vs
devenv out\vs\all.sln
```

## Third-party libraries:

[glew](https://github.com/nigels-com/glew),
[jsoncpp](https://github.com/open-source-parsers/jsoncpp),
[minimp3](https://github.com/lieff/minimp3),
[oboe](https://github.com/google/oboe),
[stb](https://github.com/nothings/stb),
[texture-compressor](https://github.com/auygun/kaliber/tree/master/src/third_party/texture_compressor),
[minizip](https://github.com/madler/zlib/tree/master/contrib/minizip),
[glslang](https://github.com/KhronosGroup/glslang),
[spirv-reflect](https://github.com/KhronosGroup/SPIRV-Reflect),
[vma](https://github.com/GPUOpen-LibrariesAndSDKs/VulkanMemoryAllocator),
[vulkan-sdk](https://vulkan.lunarg.com),
[volk](https://github.com/zeux/volk)

## Hello World example:

Shows a smoothly rotating "Hello World!".
```cpp
class HelloWorld final : public eng::Game {
 public:
  ~HelloWorld() final = default;

  bool Initialize() final {
    eng::Engine::Get().SetImageSource(
        "hello_world_image",
        std::bind(&eng::Engine::Print, &eng::Engine::Get(), "Hello World!",
                  base::Vector4f(1, 1, 1, 0)));

    hello_world_.Create("hello_world_image").SetVisible(true);
    animator_.Attach(&hello_world_);
    animator_.SetRotation(base::PI2f, 3,
                          std::bind(base::SmootherStep, std::placeholders::_1));
    animator_.Play(eng::Animator::kRotation, true);
    return true;
  }

 private:
  eng::ImageQuad hello_world_;
  eng::Animator animator_;
};

GAME_FACTORIES{GAME_CLASS(HelloWorld)};
```