/LowellCorona

Primary LanguageLua

Notes from J.A. Whye’s Mastering CoronaSDK Crash Course

Introduction

Corona is a cross-platform game framework which can build games for iOS, Android, and soon for Windows. Games are built using a language called Lua and a text editor. No fancy drag-and-drop utilities are used. I prefer this, since it allows students to learn real programming and problem solving rather than just how to use as tool. Lua is easy to learn, very similar to JavaScript, and popular in the game industry. Read this blog post for more: http://blogs.msdn.com/b/matt-harrington/archive/2014/04/09/five-reasons-schools-should-teach-corona-sdk.aspx.

Prerequisites

  1. Register on http://coronalabs.com
  2. Download and install Corona. There’s a free version.
  3. Download and install Notepad++ or TextWrangler
  4. If you're on Windows, download and install Lua for Windows from http://lua.org. This isn’t strictly necessary, but it’s nice for testing Lua snippets.
  5. Skim this introduction to Lua: http://docs.coronalabs.com/guide/start/introLua/index.html. For a good introduction to Lua, watch the Lua course on http://www.pluralsight.com by Jon Sonmez.
  6. Read this Hello World tutorial: http://docs.coronalabs.com/guide/start/helloWorld/index.html
  7. Register for J.A. Whyte’s free Game Development Crash Course: http://masteringcoronasdk.com/game-development-crash-course/

Notes from each section of the Game Development Crash Course

Space Oddity

  1. Download zip archive. Show the fully built game.
  2. Rename main-begin.lua to main.lua
  3. Walk through parts of main.lua
  4. display.newImage("background.png") -- don’t put in function
  5. display.newImage("planet.png")
  6. Note that planet is at (0,0)
  7. local planet = display.newImage("planet.png")
  8. planet.x = centerX
  9. planet.y = centerY
  10. Do same for background

Move on Down the Road

  1. transition.to(planet, { time = 2000, y = 300 }) -- put in create playscreen region

Tweaking the Display Objects

  1. planet.alpha = 0.2 -- explain what alpha is
  2. planet.alpha = 0
  3. add alpha = 1 to transition.to(planet…)
  4. Mention that display objects have lots of other properties, like xScale, rotation, etc.

Are You Through Yet?

  1. Add this callback to transition.to(planet, …): onComplete = showTitle
  2. Above transition.to(planet,…) create a showTitle() function
  3. local gameTitle = display.newImage("gametitle.png") – in showTitle()
  4. Run it
  5. gameTitle.alpha = 0; gameTitle:scale(4,4) -- in showTitle()
  6. transition.to(gameTitle, { time = 500, alpha = 1, xScale = 1, yScale = 1}) -- in showTitle()

Touch-a Touch-a, Touch-a, Touch Me

  1. Touch vs. tap: touch events have phases. We’ll use tap

Tap

  1. Put all the code we’ve written so far into a createPlayScreen() function.
  2. In spawnEnemy() put:
local enemy = display.newImage(“beetleship.png”)`
enemy.x = math.random(20, display.contentWidth – 20)
enemy.y = math.random(20, display.contentHeight – 20)
  1. Call spawnEnemy() after startGame(). Run it a few times to see the random enemy position.
  2. Move spawnEnemy() to showTitle(). You’ll get an error if you run. Put local spawnEnemy into forward declaration region. Make spawnEnemy() not local.
  3. enemy:addEventListener(“tap”, shipSmash) -- add to spawnEnemy()
  4. local obj = event.target ; display.remove(obj) -- add to shipSmash()
  5. To stop processing an event listener, put return true in the callback

Bleep, Bloop! Pew, Pew!

  1. Put this in the preload audio region:
local sndKill = audio.loadSound(“boing-1.wav”) – in preload audio
local sndblast = audio.loadSound(“blast.mp3”) – in preload audio
local sndLose = audio.loadSound(“wahwahwah.mp3”) – in preload audio
  1. In shipSmash(), put audio.play(sndKill)

Text

  1. Remove call to spawnEnemy()
  2. Remove call at bottom to startGame()
  3. Put this in startGame():
local text = display.newText("Tap here to start. Protect the planet!", 0, 0, "Helvetica", 24)
text.x = centerX
text.y = display.contentHeight - 30
  1. Call startGame() at end of showTitle()
  2. Add an event listener to dismiss the text: text:addEventListener("tap", goAway)
  3. Create goAway():
	local function goAway(event)
		display.remove(event.target)
		text = nil
		spawnEnemy()
	end