OpenWare (Minimal RenderWare-Style Engine)

OpenWare is a minimal open-source 3D engine prototype in a retro low-poly style inspired by RenderWare.

Features

• C++17 modular architecture
• OpenGL rendering with SDL2 window/input backend
• Core math (Vec2, Vec3, Mat4, Transform)
• Gameplay foundation:
  • game state machine (Playing / Paused)
  • fixed timestep simulation loop (60 Hz)
• Scene system (Entity, Scene, Camera, DirectionalLight)
• Renderer system (Shader, Mesh, Material, Renderer)
• Physics module with rigid bodies, gravity, impulses, and sphere collision response
• Resource loading:
  • OBJ mesh loader (.obj)
  • PPM texture loader (.ppm)
  • material loader (.mat)
• Optional Lua scripting callbacks (enabled when Lua is installed)
• Optional audio SFX via SDL2_mixer (enabled when installed)
• Debug UI overlay:
  • FPS and frame time
  • Settings menu on Esc

Project Structure

• include/Engine/Core - math and transform
• include/Engine/Renderer - rendering interfaces and OpenGL glue
• include/Engine/Scene - scene, entity, camera, light
• include/Engine/Physics - simple collision system
• include/Engine/Audio - audio wrapper (SDL2_mixer)
• include/Engine/Script - Lua scripting wrapper
• include/Engine/Input - SDL2 input wrapper
• include/Engine/Resource - OBJ/PPM loaders
• include/Engine/UI - debug HUD/settings UI
• src/... - module implementations
• api/ - C shared library API and Python HTTP API examples
• assets/ - demo resources (cube.obj, checker.ppm, .mat, scripts)
• docs/ - engine system and integration docs

Dependencies (Fedora)

sudo dnf install gcc-c++ cmake ninja-build SDL2-devel mesa-libGL-devel pkgconf-pkg-config

Optional packages:

sudo dnf install SDL2_mixer-devel lua-devel

Build (Ninja)

All builds are expected to use the build_ninja directory.

cmake -S . -B build_ninja -G Ninja
cmake --build build_ninja -j4

Run

./build_ninja/OpenWareEngine

API Examples

The project also includes API examples in api/:

• C API in api/c (shared library openware_api)
• Python HTTP API in api/python (uses C API through ctypes)

Run the Python API server:

python3 api/python/server.py

Where To Write Your Game Code

If you are building your own game on top of this engine, start here:

• src/main.cpp - main game entry point and loop.

Recommended places inside src/main.cpp:

• Scene setup block: create your entities, materials, lights, and initial transforms.
• Per-frame update block (inside while (running)): implement gameplay logic, AI, custom controls, and game rules.

Typical workflow:

• Keep engine modules inside include/Engine and src/... reusable.
• Put game-specific logic in src/main.cpp first.
• When your game grows, move game code into your own files (for example src/Game/...) and call them from main.cpp.

Controls

Camera

• W/A/S/D - move
• Q/E - down/up
• Mouse - look around
• Space - apply upward impulse to the dynamic test object
• P - toggle Playing / Paused

Debug / UI

• Esc - open/close settings menu
• F1 - show/hide debug HUD
• F2 - open/close About panel
• F10 - exit

Settings Menu (when open)

• 1 - toggle wireframe
• 2 - toggle VSync
• 3 - cycle shading steps (2/4/8) for stylized low-poly lighting
• 4 - toggle background music on/off (if assets/audio/music.wav exists)
• 5 - toggle PS2 aesthetic mode
• 6 - cycle PS2 color quantization levels (8/12/20)
• 7 - cycle vertex jitter amount
• 8 - cycle fog strength

Notes

• The engine is intentionally minimal and designed to be extended with animation, audio, richer physics, ECS, and tooling.
• In headless environments, runtime may fail with No available video device even though compilation succeeds.
• Detailed docs are in docs/README.md.