raysan5/game_porting_adventures.md

This article details my adventures and disadventures while porting my +9 years old XNA games (originally for Windows Phone) to MonoGame framework (Android and Desktop platforms).

At the beginning of 2012 I decided to create emegeme and start developing games. I got some experience with XNA framework so I decided to develop games for the new Windows Phone platform that was recently published and it was supported by the framework.

First game I developed was DART that TARGET, a darts arcade game. It took me about 3 months of work to create all the graphics and write all the code, it was released by April 2012. Sales were terrible.

DART that TARGET XNA game screenshots. I really put a lot of care in details, you can touch the neons for some sparks!.

DART that TARGET XNA source code development cost estimation analyzed with scc 3.0.0. A really motivational tool to evaluate my productivity.

Despite DART that TARGET did not work as expected, I decided to develop a second game, FLIPS, a memory cards game. FLIPS development took me about 4 months and it was released at the beginning of September. I put a lot of effort on localization (9 languages supported), it delayed the release a bit.

FLIPS XNA game screenshots. Again, I put a lot of care in details. I draw the 64 veggies cards available by hand!.

FLIPS XNA source code development cost estimation analyzed with scc 3.0.0. It does not reflect the amount od work it ook me to create all the art!

Again, sales were terrible but thanks to that game I got a job offer to teach some videogames development lessons at a private educational institution, only for a couple of weeks... that turn into a 6 years full-time job!. During that time, I started a new project called raylib but that's another story.

By the end of 2014, I decided to give emegeme another try and, with the help of some of my students, we started working on games development again. By that time raylib was already a thing and some of the development efforts were put on it, actually, some of those efforts were the origin of raygui and several raylib features.

Beside raylib, two videogames project were started, one was Koala Seasons, a raylib game for Android that was never released on that platform but open-sourced and released for web later on.

Second videogame project was a port of FLIPS to other platforms. XNA was discontinued by Microsoft and MonoGame seemed to be the best alternative but it has many dependencies and the custom content processor tool was not ready yet, so, I decided to use SharpDX, a lightweight alternative to support Windows desktop platform; actually, MonoGame was using SharpDX internally at that moment.

FLIPS port from XNA to SharpDX started on November 2014 and it was done in parallel with another two big game changes: a redesign from portrait to landscape mode (to better accomodate on Windows desktop) and a code split for Engine and Game, the engine was called geme. The plan was using that engine for future projects... never happened.

geme game engine logo and structure. It was a very simple engine with just a bunch of classes, intended for 2D games.

By the end of 2014 FLIPS was already running on Windows desktop, it was nice, it allowed the project to live a bit longer than on a Windows-Phone-only platform but from a business point of view, Windows desktop was not the best platform for that kind of game (or that was what I thought at that moment). I decided to port the game again to a new platform: PSVita, using PlayStation Mobile (PSM).

PlayStation Mobile platform had been around for some time and it was intended for independent developers, the most interesting feature was that it supported C# to code games (using Mono), so, it seemed a really nice fit for FLIPS.

PSM API was similar in some aspects to XNA but it required more work than SharpDX to port so, this time the port approach was a bit different, instead of replacing all XNA functionality by PSM equivalents, I decided to create an auxiliar library to map XNA to PSM, that library was called XNA2PSM.

I'm not an expert on games porting but during those ports I realized that, usually, porting a game between platforms requires reviewing some common elements. I thing most SDKs provide this kind of base elements:

• Graphics Device Manager: Functions for Graphic Device initialization and drawing on it.
• Content Manager: Functions to manage loading/unloading assets data.
• Inputs Manager: Functions to read and manage inputs, usually Keyboard, Mouse, Gamepad and Touch inputs.
• Storage Manager: Functions to access some persistent storage system to save and load game info.
• System-specific features: For example networking, ads, trophies, system-level error messages, etc.

Porting FLIPS to PSM took longer than expected, about 5 months and it was finally released on June 2015. Worth noting that I was working full-time as a teacher while developing those projects.

Unfortunately, Sony announced that the PSM store was closing by 15 July 2015, so, FLIPS was on the market for about 1 month until it dissapeared forever. At that moment I stopped XNA/SharpDX/PSM development and I focused on raylib.

FLIPS on PSVita Video

It was more than 6 years since FLIPS last release and more than 9 years since last DART that TARGET release. I had not touched those projects in that time; emegeme was mostly abandoned and all my efforts on those years were put on raylib and raylib technologies, where I developed several tools using raylib and raygui.

A couple of weeks ago I released raylib 4.0, it's been 8 years working on that project, mostly coding in C and last week I decided to take a raylib small break and try something different. I decided to review and publish FLIPS and DART that TARGET again.

I decided to port them to latest MonoGame, this framework has improved a lot and now it supports multiple platform seamlessly.