ComposeGDK

The goal of Compose Game Development Kit, is to provide a Multiplatform Game SDK based on Compose. It is a 2D Game Engine ideal to build old-school games like Platform, Puzzle or Fight Games.

Please checkout the wiki for latest news and development directions

Disclaimer

This is not a game, this is a development kit to build games.

This is not a Google or JetBrains project, this is not supported by any company (yet). Given the experimental nature of this project, I can't guarantee much support at this stage. I hope we can build a community so that this become a strong library.

Install

Compose GDK requires Java 11 or above. It can be installed with homebrew (MacOS)

$ brew install java11
$ sudo ln -sfn /usr/local/opt/openjdk@11/libexec/openjdk.jdk /Library/Java/JavaVirtualMachines/openjdk-11.jdk

Verify the version is correct

$ /usr/libexec/java_home
$ java -version

then run for MacOS 💻:

$ ./gradlew run

then run for Android 🤖:

$ ./gradlew installDebug

Roadmap 🗺

• [ 20%] Scroll and parallax
• [ 20%] Basic character/object movement (forward, backward, jump)
• [ 30%] Collision support
• [ 40%] Keyboard support
• [ 10%] Score system
• [ 10%] Touch Controller support (Touch screen joystick)
• [ 0%] Introducing more example of game
• [ 0%] Gravity / Physical support
• [ 0%] Performance and optimisations
• [ 0%] Sound support
• [ 0%] Animated image (GIF-like)
• [ 0%] Play/pause
• [ 0%] Save mechanism
• [ 0%] Multi-player (2 people with 1 keyboard, MacOS only)
• [ 0%] Game Controller support (XBox, PS4+)
• [ 0%] Local Multi-player (with multiple Game Controller)
• [ 0%] Network
• [ 0%] Multi-player over Network
• [ 0%] Mouse support
• [ 0%] Accelerometer support

Main principles

CGDKObject (GameObject)

the simplest object is CGDKObject, it has position and size, this can be extended to place more complex object on the screen, such as ImageCGDKObject.

GameCanvas

The GameObjects are placed on the Game Canvas

Animation / Scroll

Both Horizontal and Vertical scroll have been implemented, they support speed which can be use to create a parallax effect

Collision detector

The collision detector is very simple at this stage, it help to determine if 2 objects has entered in collision, this is useful to prevent object going too far, determine if the hero has encourter an ennemie or to implement gravity.

Controllers

• A Simple Keyboard controller that have 4 directions is implemented
• A Draft of Touch and Joystick Virtual Controller (for touch screen) is implemented

Score

A basic score controller has been implemented: ScoreManager

Image / Resource Loader

Image loader leverage expected and actual to load images from different location depending on the platform. Currently, it loads the images as follows:

Compose Desktop

Images are loaded from the resources folder ./common/src/commonMain/resources/

Android

Images are loaded from the assets folder ./android/src/main/assets/ by using a symbolic link to prevent having to duplicate the assets.

Target state

Ideally the images should be place in a single folder accessible from both Desktop and Android.

Known Issues

Any help on the following will be appreciated:

• unable to build the library with ./gradlew build, it's showing Execution failed for task ':common:compileKotlinMetadata' because the some Paint attributes can't be resolved (but works when running, on both Android and MacOS)

  Texture.kt
  Unresolved reference: isAntiAlias
  Unresolved reference: shader
  Unresolved reference: drawPaint
  Unresolved reference: reset
  

How can I help?

Addressing issues

• Check the know issue list and tackle one if you feel like

Creating a simple Game

• Create a simple game and provide feedback on your experience.
  • RPG Game: Zelda-like
  • Fight Game: Street fighter-like
  • Puzzle Game: Candy crush-like
  • Platform Game: Mario-like

Tackle the roadmap

They are still a lot of work to get to a complete GDK.

The top 2 priorities are:

• touch controllers for Android and touch screens. Please see see UIVirtualArrowController
• Physic/Gravity engine this will help to build cool Platform games where the character need to jump and land on piece of decor.

Examples

Platform Game mario-like