A very simple and inefficient version of Snake written in Ada / SPARK
This is a very simple and inefficient implementation of the famous Snake game in Ada / SPARK. The goal is to control the Snake, eating as much food as possible without crashing into the wall or biting itself into the tail.
This program was created in the context of a programming assignment during the course "Real-Time Programming Languages" at the TUM (Technical University Munich) - http://www.rcs.ei.tum.de/en/courses/lectures/rtpl/
The core game logic is written in SPARK, with some properties/contracts added and verified. As some part of the assignment was to make use of a selected feature set of Ada / SPARK, code quality might not be optimal :)
Please download and install GPS from https://www.adacore.com/download/more to compile to program (optionally also SPARK to verify the code).
For graphical output, GtkAda is used. So be sure to download and install it from https://www.adacore.com/download/more, following the details in README.txt.
For Linux, please use "snake.gpr". For Windows, please use "snake_windows.gpr.
In order to prove with SPARK, 'with "gtkada"' has to be changed to reference the absolute path of "gtkada.gpr" in snake.gpr. E.g. on Linux this usually has to be with "/opt/gnat/lib/gnat/gtkada.gpr";
See "snake_gnatprove.gpr" for an example.
Otherwise SPARK won't be able to locate it and report an error when trying to run gnatprove.
Starting Snake out of GPS works just fine. However, starting it directly from command line usually does not work reliably, as the GtkAda setup (e.g. environment variables) is messed up. Then, it can happen that the game output will not work reliably - esp. showing up with quite some delay. This is usually indicated e.g. by "GdkPixbuf-WARNING".
The game will start immediately after starting the program. To restart, press "r". To quit, press "q". The Snake can be controlled with the arrows on the keyboard or alternatively with a-w-s-d.
David Hildenbrand david.hildenbrand@gmail.com