mkxp is a project that seeks to provide a fully open source implementation of the Ruby Game Scripting System (RGSS) interface used in the popular game creation software "RPG Maker XP" (trademark by Enterbrain, Inc.), with focus on Linux. The goal is to be able to run games created with the above software natively without changing a single file.
Matz's Ruby Interpreter, also called CRuby, is the most widely deployed version of ruby. If you're interested in running games created with RPG Maker XP, this is the one you should go for. MRI 1.8 is what was used in RPG Maker XP, however, this binding is written against 2.0 (the latest version). For games utilizing only the default scripts provided by Enterbrain, this binding works quite well so far. Note that there are language and syntax differences between 1.8 and 2.0, so some user created scripts may not work correctly.
mruby is a new endeavor by Matz and others to create a more lightweight, spec-adhering, embeddable Ruby implementation. You can think of it as a Ruby version of Lua.
Due to heavy differences between mruby and MRI as well as lacking modules, running RPG Maker games with this binding will most likely not work correctly. It is provided as experimental code. You can eg. write your own ruby scripts and run them.
Some extensions to the standard classes/modules are provided, taking the RPG Maker XP helpfile as a quasi "reference". These include Marshal, File, FileTest and Time.
**Important:** If you decide to use [mattn's oniguruma regexp gem](https://github.com/mattn/mruby-onig-regexp), don't forget to add `-lonig` to the linker flags to avoid ugly symbol overlaps with libc.
This binding only exists for testing purposes and does nothing (the engine quits immediately). It can be used to eg. run a minimal RGSS game loop directly in C++.
mkxp employs Qt's qmake build system, so you'll need to install that beforehand. Alternatively, you can build with cmake (FIXME: add cmake instructions).
qmake will use pkg-config to locate the respective include/library paths. If you installed any dependencies into non-standard prefixes, make sure to adjust your `PKG_CONFIG_PATH` variable accordingly.
The exception is boost, which is weird in that it still hasn't managed to pull off pkg-config support (seriously?). *If you installed boost in a non-standard prefix*, you will need to pass its include path via `BOOST_I` and library path via `BOOST_L`, either as direct arguments to qmake (`qmake BOOST_I="/usr/include" ...`) or via environment variables. You can specify a library suffix (eg. "-mt") via `BOOST_LIB_SUFFIX` if needed.
**MRI-Binding**: pkg-config will look for `ruby-2.1.pc`, but you can modify mkxp.pro to use 2.0 instead. This is the default binding, so no arguments to qmake needed (`BINDING=MRI` to be explicit).
These depend on the SDL auxiliary libraries. For maximum RGSS compliance, build SDL2_image with png/jpg support, and SDL_sound with oggvorbis/wav/mp3 support.
To run mkxp, you should have a graphics card capable of at least **OpenGL 2.0** with an up-to-date driver installed.
mkxp reads configuration data from the file "mkxp.conf" contained in the current directory. The format is ini-style. Do *not* use quotes around file paths (spaces won't break). Lines starting with '#' are comments. See 'mkxp.conf.sample' for a list of accepted entries.
As of right now, mkxp doesn't support midi files, so to use the default RTPs provided by Enterbrain you will have to convert all midi tracks (those in BGM and ME) to ogg or wav. Make sure that the file names match up, ie. "foobar.mid" should be converted to "foobar.ogg".
## Fonts
In the RMXP version of RGSS, fonts are loaded directly from system specific search paths (meaning they must be installed to be available to games). Because this whole thing is a giant platform-dependent headache, I decided to implement the behavior Enterbrain thankfully added in VX Ace: loading fonts will automatically search a folder called "Fonts", which obeys the default searchpath behavior (ie. it can be located directly in the game folder, or an RTP).
If a requested font is not found, no error is generated. Instead, a built-in font is used (currently "Liberation Sans").
\* There is an exception to this, called *mega surface*. When a Bitmap bigger than the texture limit is created from a file, it is not stored in VRAM, but regular RAM. Its sole purpose is to be used as a tileset bitmap. Any other operation to it (besides blitting to a regular Bitmap) will result in an error.
To alleviate possible porting of heavily Win32API reliant scripts, I have added certain functionality that you won't find in the RGSS spec. Currently this amounts to the following:
* The `Input.press?` family of functions accepts three additional button constants: `::MOUSELEFT`, `::MOUSEMIDDLE` and `::MOUSERIGHT` for the respective mouse buttons.
* The `Graphics` module has two additional properties: `fullscreen` represents the current fullscreen mode (`true` = fullscreen, `false` = windowed), `show_cursor` hides the system cursor inside the game window when `false`.
