Mini Game Jam

14th November, 2014

Theme: Hold The Line

Today we are having a mini "game jam". The idea is to give people a chance to get used to some of the tools and techniques they might need to take part in Ludum Dare (the next Ludum Dare event is from the 5th-8th December 2014).

For this event, we strongly suggest that people use Love2D. Love2D is a game-development framework written using lua, a small and easy-to-learn language.

Running Love2D on departmental machines

Love2D is not installed on the departmental machines. Fortunately, HackSoc has a server set up to provide various useful pieces of software that are not on the departmental machines, including Love2D.

Go to klaxon.hacksoc.org and follow the instructions there to get this working on an ITS Linux machine.

A one-minute guide to Love2D

Create a folder to contain your game:

mkdir mygame

Create a file main.lua inside that directory. The body of main.lua should probably follow the following skeleton:

function love.load()
    -- initialisation code goes here
end

function love.update(dt)
    -- simulate the passing of time---<dt> is the
    -- time (fraction of a second) that has passed
    -- since the last call to love.update
end

function love.draw()
    -- draw the current frame
end

function love.keypressed(key)
    -- handle <key> being pressed
end

function love.keyreleased(key)
    -- handle <key> being released
end

function love.mousepressed(x, y, button)
    -- handle mouse presses
end

function love.mousereleased(x, y, button)
    -- handle mouse button releases
end

(You may not need to handle all of those callbacks)

Run the game:

grprun love mygame

Love2D Resources:

The Love2D website obviously has links to many resources.
Documentation for the love namespace, in which all Love2D modules live. The modules here most likely to be useful are:
A table of all Love2D Key Constants

Lua Resources:

A brief introduction to Lua
There are many tutorials in the Lua tutorial directory. Most of these are either too basic or too sophisticated, however, the tables tutorial, the modules tutorial, and the OO tutorial are worth reading.

Other Resources & Examples:

One of the previous HackSoc Ludum Dare entries was written using Love2D: it can be found on github.

Some HackSoc committee members wrote examples to remind themselves how to use Love2D:

Hints & Tips

Don't use the Love2D physics module---it's massive overkill and lots of work.
If you want physics, it's usually easiest to write something simple from scratch based on velocities and magic numbers. Code like
```
x = x + vx * dt

y = y + vy * dt
```
is very common.
Don't worry too much about good software design.
Some use of Lua's "OO" features will make life easier (but see above about not getting hung up on good design).