Skylicht Engine

Skylicht Engine is an evolution of the Irrlicht Project. We have upgraded many features, including Sound Engine, Physics Engine, Particle Engine...

• Core functionality: Direct3D11, OpenGL 4+, OpenGLES 3+, Google Angle GLES video driver backends.

• Cross-Platform Framework: Android, IOS, Win32/Win64, UWP, Linux, MacOS, HTML5.

• Render pipeline: Forwarder & Deferred.

Skylicht Engine is a super lightweight Game Engine that targets mobile platforms (Android, IOS). And, it's completely free.

How to build the project

Platform	Build Status
Cygwin64
Windows
MacOS, IOS
Linux
Emscripten
Android

Prerequisites

• CMake 3.12 or higher
• Python 3.x
• Visual Studio (2017 or higher if you want to build on Windows OS)

Build source code

• Clone this repo
• Skylicht project have used the Large Files like .tga, .fbx... for demo samples, so you must install Git LFS

# call 'git lfs pull' after checkout
git lfs pull

• Build assets bundle

C:\skylicht-engine>cd Assets
C:\skylicht-engine\Assets>python BuildAssetBundles.py
C:\skylicht-engine\Assets>cd ..

• Run CMake from the current directory to generate visual studio project or xcode project

# Visual Studio 2019
C:\skylicht-engine>cmake -S . -B ./PrjVisualStudio -G "Visual Studio 16 2019" -A x64

# Visual Studio 2022
C:\skylicht-engine>cmake -S . -B ./PrjVisualStudio -G "Visual Studio 17 2022" -A x64

# Xcode
/User/Skylicht/Documents/skylicht-engine$cmake -S . -B ./PrjMac -G Xcode 

# Linux
$ skylicht-engine$ cmake -S . -B ./PrjLinux -G "Unix Makefiles"

• Open the generated solution PrjVisualStudio/SKYLICHT_ENGINE.sln

• Once the solution opens, right click the SampleXXX project, click "Set as StartUp Project" and click the play button at the top to run the Demo App.

• More details: please preview command in BuildCommand folder.

Build data assets

Compress Texture

• Optional, You can skip this step if you don't modify any resource texture.
• This python tool will convert texture .TGA to compressed texture (.DDS, .ETC2, .PVRTC) to optimize gpu memory on runtime.

# Install Tinydb
# https://pypi.org/project/tinydb
C:\skylicht-engine>C:\Python37\Scripts\pip install tinydb

# Install Pillow (Image processing)
# https://pillow.readthedocs.io/en/4.1.x/index.html
C:\skylicht-engine>C:\Python37\Scripts\pip install Pillow

# Compress TGA to DDS, ETC2 texture
C:\skylicht-engine>cd Assets    
C:\skylicht-engine\Assets>python BuildTextureCompressDDS.py
C:\skylicht-engine\Assets>python BuildTextureCompressETC.py
C:\skylicht-engine\Assets>cd ..

Build Shader

• Optional, You can skip this step if you don't modify any shader.
• This python tool use C Preprocessor to inline shader (GLSL, HLSL) script.

# Install pcpp (C Preprocessor tool)
# https://pypi.org/project/pcpp
C:\skylicht-engine>C:\Python37\Scripts\pip install pcpp

# Build shader script
C:\skylicht-engine>cd Assets
C:\skylicht-engine\Assets>python BuildShader.py
C:\skylicht-engine\Assets>cd ..

• You can optimize shader for rendering on IOS, Android by recompiling the shader with HARD_SHADOW.

// Assets\BuiltIn\Shader\Shadow\GLSL\LibShadow.glsl

#define HARD_SHADOW
// #define PCF_NOISE

And re-build the shaders

# Build shader script
C:\skylicht-engine>cd Assets
C:\skylicht-engine\Assets>python BuildShader.py
C:\skylicht-engine\Assets>cd ..

Add your code to Project

Add source code

• Add new source files or subfolders on Projects/{ProjectName}/Source and regenerate project

C:\skylicht-engine>cmake -S . -B ./PrjVisualStudio -G "Visual Studio 17 2022" -A x64

Create application project

• Run Scripts/create_project.py. Example: Create application NewApplication at folder Samples\NewApplication

    C:\skylicht-engine>python Scripts\create_project.py NewApplication Samples\NewApplication

• Edit CMakeProjects.cmake, add new line:"subdirs (Samples/NewApplication)" and regenerate projects
• Open Visual Studio Solution and click NewApplication - "Set as StartUp Project".

Android

Prerequisites

• Install Android Studio and SDK
• Install mingw-w64 for Windows
• Install Android NDK

How to build

Step 1: Build native library

• Edit the file BuildCommand/BuildAndroidNDK.cmd by text editor and update your path MINGW and NDK

# BuildAndroidNDK.cmd
# Set your pc folder, example
set MINGW=C:\MinGW\bin
set NDK=C:\Android\android-ndk-r26d
...

• Run BuildCommand/BuildAndroidNDK.cmd to build android native library

Step 2: Copy native library to Gradle Project

# Make folder jniLibs on Android Project
C:\skylicht-engine>mkdir Projects\Android\app\src\main\jniLibs
C:\skylicht-engine>mkdir Projects\Android\app\src\main\jniLibs\armeabi-v7a
C:\skylicht-engine>mkdir Projects\Android\app\src\main\jniLibs\arm64-v8a

# Copy result native ndk (from step 1) to jniLibs
# Project SampleSkinnedMesh
C:\skylicht-engine>copy Bin\Android\Libs\arm64-v8a\libSampleSkinnedMesh.so Projects\Android\app\src\main\jniLibs\arm64-v8a
C:\skylicht-engine>copy Bin\Android\Libs\armeabi-v7a\libSampleSkinnedMesh.so Projects\Android\app\src\main\jniLibs\armeabi-v7a

Step 3: Copy asset resource to Gradle Project

C:\skylicht-engine\Assets>python BuildTextureCompressETC.py
C:\skylicht-engine\Assets>python BuildAssetBundles.py
C:\skylicht-engine\Assets>cd..

Android APK:

C:\skylicht-engine>SET ASSET_PATH=Projects\Android\app\src\main\assets

Android AAB: Assets will be copied to assetPack: appdata

C:\skylicht-engine>SET ASSET_PATH=Projects\Android\appdata\src\main\assets

And copy command

# Copy built-in asset
C:\skylicht-engine>copy Bin\BuiltIn.zip %ASSET_PATH%

# Copy project asset
# Project SampleSkinnedMesh
C:\skylicht-engine>copy Bin\Common.zip %ASSET_PATH%
C:\skylicht-engine>copy Bin\SampleModelsResource.zip %ASSET_PATH%

# Dont forget copy ETC texture
C:\skylicht-engine>copy Bin\SampleModelsETC.zip %ASSET_PATH%

Step 4: Build APK by Android Studio or Gradle

Open Android Studio and import project Projects\Android

Run command build from Android Studio:

Android development

• You can rename your package name at build.gradle (Projects\Android\app)
• You can rename your application name at string.xml (Projects\Android\app\src\main\res\values)

iOS

Prerequisites

• Apple arm64 device
• Install XCode

How to build

Step 1: Build compress texture ETC and Build Asset Bundles

# Grant permission executive for PVRTexTool
skylicht-engine/Tools/PVRTexTool/darwin$ chmod +x PVRTexToolCLI

# Build compress texture ETC
skylicht-engine/Assets$ python3 BuildTextureCompressETC.py

# Build asset bundles
skylicht-engine/Assets$ python3 BuildAssetBundles.py

Step 2: Generate iOS xCode Project

If you want build samples for iOS device, you should replace the bundleIdentifier in Samples/{ProjectName}/CMakeLists.txt.

elseif (BUILD_IOS)
    # replace your application name
    set(MACOSX_BUNDLE_EXECUTABLE_NAME SampleHelloWorld)
    set(APP_NAME "SampleHelloWorld")
    
    # replace your bundleIdentifier
    set(APP_BUNDLE_IDENTIFIER "com.skylicht.helloword")
    set(CODE_SIGN_IDENTITY "iPhone Developer")
    
else()

And generate iOS xCode Project by this script.

# generate project for iOS device
skylicht-engine/BuildCommand$ ./GenerateXCodeIOS.sh

# or generate for iOS simulator
skylicht-engine/BuildCommand$ ./GenerateXCodeIOSSimulator.sh

Open iOS XCode Project on folder skylicht-engine/PrjIOS/SKYLICHT_ENGINE.xcodeproj

Note: iOS Simulator is not yet support compressed texture and hardware skinning.

Build static or shared library

Skylicht Engine can be compiled into a standalone library to simplify integration into other projects.

Shared library

C:\skylicht-engine>cmake -S . -B ./PrjVisualStudio -G "Visual Studio 17 2022" -A x64 -DINSTALL_LIBS=ON -DBUILD_SHARED_LIBS=ON
C:\skylicht-engine>cmake --build ./PrjVisualStudio --target install --config Debug

Note: Use the parameters "-DINSTALL_LIBS=ON -DBUILD_SHARED_LIBS=ON" with cmake command

Static library

C:\skylicht-engine>cmake -S . -B ./PrjVisualStudio -G "Visual Studio 17 2022" -A x64 -DINSTALL_LIBS=ON
C:\skylicht-engine>cmake --build ./PrjVisualStudio --target install --config Debug

How to integrate

And then copy the resulting InstallLibs folder to another project. See the project example: https://github.com/skylicht-lab/hello-skylicht See the API Reference

Roadmap

• Skylight Engine Core
• Engine Editor

Code example

// INIT SCENE FUNCTION
// init scene/zone
CScene* scene = new CScene();
CZone* zone = scene->createZone();

// camera
CGameObject *camObj = zone->createEmptyObject();
CCamera* camera = camObj->addComponent<CCamera>();
camera->setPosition(core::vector3df(0.0f, 1.5f, 4.0f));
camera->lookAt(
   core::vector3df(0.0f, 0.0f, 0.0f),  // look at target position
   co