Question

Right now we have all our code gathered in main.lua. We don’t want to work with object oriented code, but still find an easy way of splitting the different objects up into separated files.

In our main.lua file we have objects like water, boat, boy, island and cloud – all together creating one massive bit of code. We want to have “BEGIN WATER 3” in it’s own lua file and be able to execute that code in main.lua with a simple function instead. How do we do that?

Here an example from our main.lua file, displaying “water3”:

--------------- BEGIN WATER 3 ---------------------------------------------------------

local watere = display.newImage( "water3.png", true )
game:insert( watere )
watere.y = 619
watere.x = 500
watere.xScale = 2

--water sound
local wavesound5 = media.newEventSound("waves.wav")

local function playWave5 (event)
  media.playEventSound(wavesound5)
end

local w,h = display.contentWidth, display.contentHeight

local function callbackFunc()
  print( "Transition 1 completed" )
end

local function mainwater(watere)
end

function loopar()
  local myTween = transition.to(watere, {time=2300, x=(400), y=(h-140), transition=easing.inOutQuad, onComplete=loopar2})
end

function loopar2()
  local myTween = transition.to(watere, {time=2200, x=(w-500), y=(h-120), transition=easing.inOutQuad, onComplete=loopar})
end

local listener2 = function()
  print( "Transition 2 completed" )
end

local myTween = transition.to(watere, {time=2300, x=(w-400), y=(h-140), transition=easing.inOutQuad, onComplete=loopar})

watere:addEventListener("touch", playWave5)

---------------- END WATER 3 ---------------------------------------------------------

Answer 1

On this other answer I’ll try to implement what I think you want. Keep in mind that I have never used CoronaSDK, so it might need some debugging.

First, here’s a file called create.lua . You should place it on the same directory as main.lua.

The main objective of create.lua is building a table called create. That table only has one function for creating water; you can add more functions later, for example for creating ground.

-- file 'create.lua'

local function water(game,x,y,xScale,imagePath,soundPath)

  local image = display.newImage( imagePath )
  game:insert( image )

  image.x, image.y, image.xScale = x, y, xScale

  local w,h = display.contentWidth, display.contentHeight

  -- create two empty local variables and assign functions to them
  local loopar, loopar2
  loopar = function() transition.to(image, {time=2300, x=(400), y=(h-140), transition=easing.inOutQuad, onComplete=loopar2}) end
  loopar2 = function() transition.to(image, {time=2200, x=(w-500), y=(h-120), transition=easing.inOutQuad, onComplete=loopar}) end

  -- start the movement
  transition.to(image, {time=2300, x=(w-400), y=(h-140), transition=easing.inOutQuad, onComplete=loopar})

  local sound = media.newEventSound(soundPath)
  image:addEventListener("touch", function() media.playEventSound(sound) end )
end

local create = { water = water }

return create

Inside main.lua, in order to be able to use create.water first you have to get access to that create table; you use require for that. Like this:

-- file 'main.lua'

local create = require 'create'

<put the code for creating the 'game' group here>

create.water(game, 619, 500, 2, "water3.png", "waves.wav")

Notice that create.water receives parameters. You can change the parameters more easily now:

create.water(game, 200, 100, 2, "water3.png", "waves.wav") -- other initial coordinates
create.water(game, 619, 500, 1, "water3.png", "waves.wav") -- scaleX = 1
create.water(game, 619, 500, 1, "water.png", "waves.wav") -- other water img

Regards!