A general-purpose game engine for the Nintendo® Game Boy Advance™

Saturn aims at providing a plethora of functionality and toolsets for building 2D video games on the Nintendo Game Boy Advance. It is written in a mixture of C, C++ and assembly, and will provide an Entity–Component–System framework for building applications.

Here is a short list of some of the things Saturn hopes to provide:

• Classes and functions that make working with graphics more human
• A frame-based asynchronous task system
• A mainloop complete with a modifiable set of purposed callbacks
• A console interface that switches between input and output upon Select
• More abstractions for key input, sound, and link cable networking
• a dual-mode topdown graphics layout, either on a grid or unrestricted, plus a sidescrolling platformer layout
• A collection of PC utilities that help make creating Saturn projects easier
• A fully automated and distributed build system used to build GBA titles as well as the engine itself

Saturn is Free Software. That means you can distribute, modify, and use it in any way you please, without restriction. To be specific, Saturn is released under the Apache License 2.0.

We have some notes regarding the usage of this engine to build titles for the GBA. We ask that you read over them to ensure that you enjoy a seamless development experience with our work.

• While the majority of the engine is kept in C++ namespaces to prevent naming collisions, this is not always possible as some of the code must be written in assembly where namespaces do not exist. To alleviate this issue, we have reserved all symbols beginning with _sat__ for internal use by the engine, and ask that you do not create functions bearing this prefix for safety’s sake. This is in addition to ISO C’s reservation of symbols starting with an underscore followed by a capital letter, and ISO C++’s reservation of symbols starting with a double underscore.
• Saturn has a Simplified & Segregated Working Memory Model – a minimum of space is reserved towards the end of IWRAM for things required by hardware, with the remainder left entirely to static code/data and a full decrementing user stack. Likewise, the entirety of EWRAM is reserved for the program heap.