Momo Engine

A modern game engine built with Vulkan and C++20, featuring cross-platform support via MoltenVK on macOS.

Features

• Vulkan Renderer: Modern graphics API with MoltenVK support for macOS
• GLFW Integration: Cross-platform window and input management
• Layer-based Architecture: Modular application structure with layer system
• C++20: Modern C++ features and best practices
• CMake Build System: Cross-platform build configuration with presets

Prerequisites

Windows

• Visual Studio 2022 (or Build Tools for Visual Studio 2022) with C++ workload
• CMake (3.21+): Install via cmake.org or winget install Kitware.CMake
• Ninja: winget install Ninja-build.Ninja (or include via Visual Studio)
• LLVM/Clang (optional, for clang presets): winget install LLVM.LLVM
• Vulkan SDK: Download from LunarG
  • Run the installer and ensure "Shader Toolchain Debug Symbols" is selected
  • The installer automatically sets VULKAN_SDK environment variable

macOS

• Xcode Command Line Tools: xcode-select --install
• CMake (3.21+): brew install cmake
• Ninja: brew install ninja
• Vulkan SDK: Download from LunarG
  • Install the macOS SDK (includes MoltenVK)
  • Current tested version: 1.4.328.1

Environment Setup

Windows

The Vulkan SDK installer automatically configures the required environment variables. Verify by opening a new terminal and running:

echo $env:VULKAN_SDK

If using Clang, ensure it's in your PATH:

clang --version

macOS

Add the following to your ~/.zshrc (or ~/.bashrc for Bash):

export VULKAN_SDK="$HOME/VulkanSDK/1.4.328.1/macOS"
export PATH="$VULKAN_SDK/bin:$PATH"
export DYLD_LIBRARY_PATH="$VULKAN_SDK/lib:$DYLD_LIBRARY_PATH"
export VK_ICD_FILENAMES="$VULKAN_SDK/share/vulkan/icd.d/MoltenVK_icd.json"
export VK_LAYER_PATH="$VULKAN_SDK/share/vulkan/explicit_layer.d"

After editing, reload your shell configuration:

source ~/.zshrc  # or source ~/.bashrc

Building

Windows

Use the Clang preset (requires LLVM/Clang installed):

# Configure (Debug)
cmake --preset clang-debug

# Build
cmake --build build/clang-debug

# Or for Release builds
cmake --preset clang-release
cmake --build build/clang-release

The executable will be created at build/clang-debug/application/khclone.exe.

macOS

The project includes macOS-specific build presets that use the system AppleClang compiler:

# Configure (Debug)
cmake --preset macos-debug

# Build
cmake --build build/macos-debug

# Or for Release builds
cmake --preset macos-release
cmake --build build/macos-release

The executable will be created at build/macos-debug/application/khclone.

Alternative: Generic Clang Presets

On macOS, if you prefer to use a different clang installation:

cmake --preset clang-debug
cmake --build build/clang-debug

Running

After building, run the application:

Windows:

.\build\clang-debug\application\khclone.exe

macOS:

./build/macos-debug/application/khclone

You should see output similar to:

[Momo] Starting 'KHClone' (1920x1080)
[VulkanRenderer] Creating Vulkan instance...
[AppLayer] Attached to application.

Technology Stack

• Graphics API: Vulkan 1.3+ (via MoltenVK on macOS)
• Windowing: GLFW 3.4
• Language: C++20
• Build System: CMake 3.21+ with Ninja generator
• Platforms: Windows 10/11, macOS (Apple Silicon and Intel)

Development

Adding New Layers

The engine uses a layer-based architecture. To create a new layer:

class MyLayer : public Momo::Layer
{
public:
    void OnAttach() override
    {
        // Initialize layer resources
    }

    void OnUpdate(float dt) override
    {
        // Update logic
    }
};

// In main.cpp
app.PushLayer<MyLayer>();

CMake Presets

Available presets:

• macos-debug: macOS with system AppleClang (Debug)
• macos-release: macOS with system AppleClang (Release)
• clang-debug: Generic Clang (Debug)
• clang-release: Generic Clang (Release)

Compiler Warnings

The project is configured with strict compiler warnings:

• GCC/Clang: -Wall -Wextra -Wpedantic
• MSVC: /W4 /permissive-

MoltenVK Notes

MoltenVK is a Vulkan Portability implementation that translates Vulkan calls to Metal on Apple platforms. The engine properly configures:

• VK_KHR_portability_enumeration extension
• VK_INSTANCE_CREATE_ENUMERATE_PORTABILITY_BIT_KHR flag
• MoltenVK ICD (Installable Client Driver) detection

These are handled automatically by the engine's Vulkan initialization code.

Troubleshooting

Windows: "clang not found" or CMake can't find compiler

1. Ensure LLVM is installed: winget install LLVM.LLVM
2. Add LLVM to PATH (usually C:\Program Files\LLVM\bin)
3. Open a new terminal after installation

Windows: Vulkan validation layer errors

1. Ensure Vulkan SDK is installed with validation layers
2. Check VULKAN_SDK environment variable is set
3. Try running from Developer Command Prompt for VS 2022

macOS: "ErrorIncompatibleDriver"

If you see this error, ensure:

1. Vulkan SDK is properly installed
2. Environment variables are set correctly (see Environment Setup)
3. You've reloaded your shell configuration or opened a new terminal

macOS: Build Errors with Homebrew Clang

Use the macos-debug or macos-release presets instead of clang-debug/clang-release to use the system AppleClang compiler.

GLFW Extension Errors

Ensure GLFW is being built with Vulkan support. The engine automatically fetches and builds GLFW with the correct configuration.

License

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Contributing

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