Game development

From Official Kodi Wiki
Jump to navigation Jump to search
Home icon grey.png   ▶ Games
▶ Development
▶ Game development
Home icon grey.png   ▶ Kodi Game ▶ Game development

This page is about Kodi-Game branch of Kodi which tries to implement a gaming environment for Kodi. The goal is to start, stop and play video games like you can currently play video files. Kodi-Game constist of several addons and subsystems which should be described on this page to minimize confusion. The current development builds are based on Kodi 17 (Krypton) and introduces a lot of changes, and for this reason the information you can find on the forum and here in the wiki might be outdates and may not apply. Official repository is on github.

A related topic is Game OSD skinning.

1 End-users (non-programmers)

You are probably reading this because you would like to download a finished Kodi application or complete OpenELEC image with nice out-of-the-box experience. We are sorry but such build does not yet exist at the moment. This page will be updated with links to available builds if and when such release become available.

You can help still help if you are a more experienced computer user and are able to compile Kodi-Game branch yourself, please see the developers sections below. Also, spread the word about this project to your friends and family, we are sure they will enjoy it too as it matures.

2 Developers (programmers)

If you are a C/C++ developer and like to help then great! Please checkout the Compiling Kodi-Game, Compiling Game Add-ons, and Porting Libretro cores to Game Add-ons articles to get started. Currently this build instruction is for Linux operating-systems on x86/x86-64 based hardware only.

You should be proficient in C/C++ programming language, and although not really required knowledge of OpenGL or other multimedia programming is a plus, as well as prior cross-platform or porting development experience.

3 Technical Overview

Kodi Game is the project name for all infrastructure changes which need to be made in the Kodi source code. This work also includes a highly modified input system ready for gaming requirements.

3.1 RetroPlayer

RetroPlayer is a new player core for Kodi Entertainment Center. It is similar to the video player and audio visualizer, but it plays games instead of movies and music. Player core that plays games using game add-ons. Despite its name, it can play all types of games, not just retro ones. Games can be paused, fast-forwarded, and rewound in realtime. Save states are created similar to bookmarks, allowing for quick browsing of the game's play history. 3D support (for N64, etc) is being worked on.

3.2 Game API

Game API ?

3.3 Game Add-ons

Stand-alone games or emulators that does not use the Libretro API. Possible examples could be, Nvidia GameStream via Limelight or WINE capture could possible through the Game API.

3.4 Libretro API

Libretro is a C-based interface between user-facing frontends and emulator backends. This frontend and backend concept allow several different (non-Kodi) frontend projects to use the same Libretro core emulators.[1]

Kodi's Game API has Libretro Wrapper which is 1:1 compatibility with the libretro API, so all libretro cores are valid game add-ons. Libretro itself is a well defined interface to handle the communication between a frontend (Kodi with RetroPlayer) and an Emulator Core (e.g. nestopia).

By ultilizing libretro, the Kodi Game project will also become a part of the larger software ecosystem based around libretro, this a other third-party projects use libretro as well as all to some degree collaborage and share code with upstream libretro.

3.4.1 Libretro Cores

An Emulator Core for Libretro API ( that does the actual work of emulating a system. Due to the common Libretro API interface it is possible to re-use good working and well tested emulators for the RetroPlayer platform. Every emulator that supports libretro will be relatively easily to integrate once the project matures.

3.5 Peripheral API

A way to interface DIY hardware with Kodi. Currently game controllers, and in the future also media readers for cartridge adapters.

3.6 Peripheral Add-ons

The peripheral add-ons provides access to many joystick and gamepad interfaces across various platforms. An input addon is used to map the buttons/axis on your physical input device, to the buttons/axis of your virtual system. This is necessary because different retro systems usually have different button layouts. A controller configuration utility is also in the works.

4 Subsystem Architecture

  • Game API - ?
    • Game Client Addons - ?
    • Libretro Wrapper - ?
  • Hardware API - ?
    • Peripheral API - ?
      • Peripheral Add-ons - ?
      • Peripheral Buses - ?
      • Input Library - ?
    • Media Readers API - ?
    • Input API - ?
  • RetroPlayer - ?
    • RetroPlayer Savegames - ?

4.1 Architecture development discussions:

5 Game add-ons

6 Communication:

7 FAQ for Kodi-Game branch

Common questions and answers regarding testing and development of Kodi-Game branch.

7.1 Mupen64plus (n64) is not working

Mupen64plus and some other emulators (such as PSP, Dolphin) requires OpenGL / OpenGL ES rendering extensions to libretro which is currently not implemented in the current upstream kodi-game branch. See a1rwulf's repository for his "retrogl" implementations if you would like to help the work being done for these systems.

7.2 Is it possible to support system X on platform Y

Kodi Game branch includes a wrapper for libretro to emulate multiple systems via emulator cores for its common libretro API. The current support matrix can be found in the Game add-ons wiki article.

8 See also

9 External Links

9.1 References