Legato

A Lua/Allegro5 based gaming framwork

What is Legato?

Take the famous scripting language Lua and bind it together with the powerful game framework Allegro. The result is a very flexible and fun to work with framework called Legato. So in short:

Legato = Lua + Allegro

The idea behind Legato is, to ship only a single executable which contains a Lua interpreter, Allegro 5 game framework, PhysFS virtual filesystem and the robust UDP networking library enet. If you write the game on one system, it will work on every system which is supported by Legato.

What is Legato not?

Legato is a framework which provides various functions and objects to create multimedia applications and games. It's not a ready to run game engine or a full featured 3D engine. You have to implement everything yourself.

What's implemented so far?

Almost every function and module of Allegro 5. There are only a few things, which are not implemented right now. All function calls for Allegro 5 have the same name and arguments, so take a look to http://alleg.sourceforge.net/a5docs/5.0.10/index.html and compare it to the list below.

Allegro 5

Configuration files - implemented
Display - implemented (some icons stuff is missing)
Events - implemented
File I/O - not implemented (use PhysFS instead)
Filesystem - not implemented (use PhysFS instead)
Fixed point math - not implemented (Lua uses numbers which are implemented as doubles -> makes no sense)
Fullscreen modes - implemented
Graphics - implemented (bitmap locking is missing right now)
Joystick - implemented
Keyboard - implemented
Memory - not implemented (Lua uses a dynamic memory management -> makes no sense)
Monitor - implemented (some bits missing)
Mouse - implemented
Path - implemented
State - implemented
System - implemented (some bits missing)
Threads - not implemented (and probably will never be)
Time - implemented (timeout missing)
Timers - implemented
Transformations - implemented
UTF-8 - not implemented (Lua has strings / use legato UTF8 functions)
Miscellaneous - not implemented (nothing of value here)
Platform-specific - not implemented
Direct3D - not implemented
OpenGL - not implemented

Allegro 5 - Addons

Audio addon - implemented (with audio codecs)
Color addon - implemented (missing some color to hsl etc.)
Font addons - implemented (no way to create bitmap fonts right now)
Memfile addon - not implemented
Native dialogs - not implemented (this will add even more dependencies on Linux/Unix)
PhysicsFS addon - implemendted (Legato forces the use of PhysFS)
Primitives addon - implemented (low level drawing functions missing)

PhysicsFS

Nearly all functions are implemented. Manual is here: http://www.icculus.org/physfs/docs/html/

enet (UDP networking)

Implemented all core functions. It should be useable. Manual is here: http://enet.bespin.org/

legato.core (some core functionality)

get_version()
get_version_string()
load_script(filename)
encode_UTF8_codepoint(codepoint)
get_UTF8_length(string)
split_UTF8_string(string)

How to use?

Hmm. Compile legato.c on your computer (you will need Allegro 5+dependencies, PhysFS, Lua and enet). If you don't know how to do this, ask a nice person to do it. You can use the executable for every game you going to create.

Windows 32bit http://lauter-helden.de/legato/download/current/Legato.exe
Linux 32/64bit (will come soon)
MacOS X builds....sorry I can't do that

Next step. Create a directory called "data" in the directory of your executable.

Fire up your favourite editor and create a file in the "data" directory called "boot.lua".

Write some lines like:

local al = legato.al -- improve speed
local display = al.create_display(800, 600)
local event_queue = al.create_event_queue()
al.register_event_source(event_queue, display)

while true do
    local event = al.get_next_event(event_queue)
    if event then
        if event.type == 'display_close' then
            return -- stop running if display get's closed
        end
    end
    al.clear_to_color(al.map_rgb(0, 0, 0))
    al.flip_display()
    al.rest(0.1)
end

Sorry there's no real manual yet. I'm going to create some in the future :(

Bugs ?!

There may be many of them. I just started to convert some examples over to Legato. If you find something please don't hesitate and write me a mail.

Last famous words...

This project is still work in progress. But you can still use a lot of things right now. Prototyping a small game is very very efficient with that framework. Please feel free to modify and improve this code, share it with your friend and do whatever you want (even exploit it commercially if you like). But it would be nice to hear from you and let me see, what amazing stuff you going to create with it.

Thanks! Have fun and happy hacking!

Sebastian Steinhauer s.steinhauer@yahoo.de

southdy / legato