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nullstare / ReiLua

Lua game development framework based on Raylib.
MIT License
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ReiLua logo

About

Idea of this project was to bring the power and simplicity of Raylib to easy beginner friendly language like Lua in a very straight forward manner. It is loose binding to Raylib, some functions will not be included and some are added. The idea of pointing "main.lua" file and access functions "init", "update" and "draw" are borrowed from Löve game framework.

ReiLua is not planned to be a one-to-one binding to raylib. If you want more direct bindings, there are other projects like https://github.com/TSnake41/raylib-lua.

Reilua means fair in finnish.

Status

ReiLua is WIP and some planned raylib functionality is still missing but it already has over 900. Current Raylib version 5.0.

Included submodules.

List of some MISSING features that are planned to be included. For specific function, check API.

Roadmap

Usage

Application needs 'main.lua' or 'main' file as entry point. ReiLua executable will first look it from same directory. Alternatively, path to the folder where "main.lua" is located can be given as argument. There are five Lua functions that the framework will call, 'RL.init', 'RL.update', 'RL.draw', 'RL.log' and 'RL.exit'.

Example of basic "main.lua" file that will show basic windows with text.

local textColor = RL.BLACK
local textPos = { 192, 200 }
local textSize = 20
local text = "Congrats! You created your first window!"

function RL.init()
    RL.SetWindowTitle( "First window" )
    RL.SetWindowState( RL.FLAG_VSYNC_HINT )
end

function RL.update( delta )
    if RL.IsKeyPressed( RL.KEY_ENTER ) then
        local winSize = RL.GetScreenSize()
        local measuredSize = RL.MeasureTextEx( RL.GetFontDefault(), text, textSize, 2 )

        textColor = RL.BLUE
        textPos = { winSize[1] / 2 - measuredSize[1] / 2, winSize[2] / 2 - measuredSize[2] / 2 }
    end

    if RL.IsKeyPressed( RL.KEY_SPACE ) then
        textColor = RL.RED
        textPos = { 192, 200 }
    end
end

function RL.draw()
    RL.ClearBackground( RL.RAYWHITE )
    RL.DrawText( text, textPos, textSize, textColor )
end

Application folder structure should be...

GameFolder
 \ReiLua.exe
 \main.lua

Application should now start successfully from executable. All functionality can be found in "API".

ReiLua_API.lua can be put into project folder to provide annotations when using "Lua Language Server".

Object unloading

Some objects allocate memory that needs to be freed when object is no longer needed. By default objects like Textures are unloaded by the Lua garbage collector. It is generatty however recommended to handle this manually in more complex projects. You can change the behavior with:

RL.SetGCUnload()

Interpreter Mode

ReiLua can also be used to run single lua file using interpreter mode with arguments -i or --interpret. Given file will be called with dofile. Usage example:

./Reilua -i hello.lua

Generate API

Generate API.md and ReiLua_API.lua from build folder with command.

./Reilua -i ../docgen.lua

Building

I think the simplest way would be to statically link Raylib and Lua to the same executable. Specially on Linux this would simplify distribution of games since different distros tend to use different versions of librarys. Of course if you plan to only experiment with it, this isn't so important.

https://github.com/raysan5/raylib

https://github.com/lua/lua or https://github.com/LuaJIT/LuaJIT

Note! Lua header files are from Lua 5.4.0, if you use different version be sure to replace them.

Linux

Compile Raylib and lua by following their instructions. They will compile to libraylib.a and liblua.a by default.

You need build essential and cmake. If you compiled Raylib you should already have these.

sudo apt install build-essential
sudo apt install cmake

If compiling statically, move libraylib.a and liblua.a to "ReiLua/lib" folder. From "ReiLua" folder...

cd build
cmake ..
make

Run example.

./ReiLua ../examples/snake/

If you now see extremely low res snake racing off the window then you are successfull. Congratulations! You can reset the game by pressing enter.

Windows

mingw32-make
MYCFLAGS= $(LOCAL) -std=c99 -DLUA_USE_LINUX -DLUA_USE_READLINE
# to
MYCFLAGS= $(LOCAL) -std=c99

# And comment out or remove line.
MYLIBS= -ldl -lreadline
mingw32-make
cmake -G "MinGW Makefiles" ..

# Cmake uses NMake Makefiles by default so we will set the Generator to MinGW with -G

mingw32-make

Run example.

./ReiLua.exe ../examples/snake/

If you now see extremely low res snake racing off the window then you are successfull. Congratulations! You can reset the game by pressing enter.

MacOS

Not tested, but I guess it should work similarly to Linux.

Raspberry Pi

Works best when Raylib is compiled using PLATFORM=DRM. See Raylib build instructions for Raspberry Pi. Compile ReiLua with.

cmake .. -DDRM=ON

Note that DRM should be launched from CLI and not in X.

Web

Compile Raylib for web by following it's instructions. https://github.com/raysan5/raylib/wiki/Working-for-Web-(HTML5)#1-install-emscripten-toolchain

Lua can be compiled by making few changes to it's makefile.

MYCFLAGS= $(LOCAL) -std=c99 -DLUA_USE_LINUX -DLUA_USE_READLINE
# to
MYCFLAGS= $(LOCAL) -std=c99

MYLIBS= -ldl -lreadline
# to
MYLIBS= -ldl

CC= gcc
# to
CC= emcc

CFLAGS= -Wall -O2 $(MYCFLAGS) -fno-stack-protector -fno-common -march=native
# to
CFLAGS= -Wall -O2 $(MYCFLAGS) -fno-stack-protector -fno-common

AR= ar rc
# to
AR= emar

# And a little bit more down.
    $(AR) $@ $?
# to
    $(AR) rcs $@ $?

Emscripten builds the resources like lua files and images to "ReiLua.data" file so we will create folder called "resources" that should include all that. "resources" should also be included in all resource paths. "main.lua" should be located in the root of that folder. So we should now have.

ReiLua
 \build
 |\resources
 ||\main.lua

We can now build the game. You can use the command in the top of the "CMakeLists.txt" to use emsdk toolchain with cmake. Remember to replace \ with correct path.

cmake .. -DCMAKE_TOOLCHAIN_FILE=<YOUR PATH HERE>/emsdk/upstream/emscripten/cmake/Modules/Platform/Emscripten.cmake -DPLATFORM=Web
make

You should now have "ReiLua.html", "ReiLua.js", "ReiLua.wasm" and "ReiLua.data". You can test the game by creating localhost with Python.

python -m http.server 8080

You should now be able to access the webpage from browser.

localhost:8080/ReiLua.html