Drystal

About

Drystal is an opensource game engine.

Games are programmed in Lua and can be exported to Javascript seamlessly.

local drystal = require 'drystal'

function drystal.init()
  print('Game initialized!')
end

function drystal.draw()
  drystal.set_color('red')
  drystal.draw_background()
end

Authors

• Jérémy Anger
• Ronny Chevalier

Mailing list

https://groups.google.com/forum/#!forum/drystal

To subscribe, send an e-mail to:

drystal+subscribe@googlegroups.com

To unsubscribe, send an e-mail to:

drystal+unsubscribe@googlegroups.com

To follow via RSS:

https://groups.google.com/forum/feed/drystal/topics/rss.xml

To follow via ATOM:

https://groups.google.com/forum/feed/drystal/topics/atom.xml

License

LGPLv3 for all Drystal code

The external/ folder contains third-party libraries:

• stb_vorbis.c and stb_truetype.h which are in the public domain
• lua/* which is under the MIT License
• box2d/* which is under the zlib License
• lua-cjson/* which is under the MIT License
• wavloader.c which is in the public domain
• miniz.c which is in the public domain
• libpng/* which is under the libpng License
• zlib/* which is under the zlib License

Repository

The main repository of Drystal is hosted on Github at http://github.com/kidanger/Drystal/

You can clone this repository with the following command

git clone --recursive https://github.com/kidanger/Drystal.git

Documentation

The documentation of the current release is available in HTML format and can be found at http://drystal.github.io/

Demos

You can find games made with Drystal at https://github.com/kidanger/drystal-demos

Requirements

To build Drystal, the following tools are needed:

• CMake
• C compiler — Currently, only clang and gcc are supported.
• make or ninja — Or any generators supported by CMake
• C++ compiler (optional)
• patch (optional)

And the following optional libraries:

• SDL2
• OpenAL
• OpenGL
• libpng >= 1.6
• Box2D

When building the documentation, the following additional dependencies are needed:

• sphinx
• pip

When building a web version of Drystal, you also need Emscripten.

To use the test coverage, the following tools are needed:

• gcov
• lcov

First time

Native build

Once you cloned the repository and installed all the requirements, you can build Drystal in native mode (i.e. that will run on your computer).

make native

You can now find the executable in the build directory:

build-native-Debug/src/drystal --help

or install it:

make install-native CMAKE_FLAGS=-DCMAKE_INSTALL_PREFIX:PATH=$HOME/.local/

Web build

In order to compile Drystal to javascript you will also need to install Emscripten, then you can run:

make web

You will find the final javascript code (there will be two files drystal.js and drystal.mem.js) in the build-web-Release-src/ directory.

Build options

You can configure the build to fit to your needs, for example if you do not need the physics engine, you can run:

make native CMAKE_FLAGS="-DBUILD_PHYSICS=OFF"

Here is the list of options, their default and the additional dependencies needed to build:

Option	Default	Additional dependencies
BUILD_MANPAGES	ON	xsltproc
BUILD_ENABLE_COVERAGE	OFF	lcov, gcov
BUILD_LIVECODING	ON
BUILD_PHYSICS	ON	Box2D
BUILD_PARTICLE	ON
BUILD_WEB	ON
BUILD_FONT	ON	SDL2, OpenGL
BUILD_AUDIO	ON	OpenAL
BUILD_STORAGE	ON
BUILD_GRAPHICS	ON	SDL2, OpenGL, libpng
BUILD_UTILS	ON

The additional dependencies listed here are only for a native build. When building with Emscripten, all these dependencies are either provided by Emscripten or recompiled entirely (using a git submodule).

For the web build, removing parts of Drystal that you do not use decrease the size of the final javascript code which helps loading the page of the game faster. (e.g. removing the physics module saves ~273 KiB)