How To Make a Breakout Game with Corona

No Texting in the Zombie Apocalypse

It's now time to create the text box that gives the user feedback and lets them retry a level or move onto the next. Here's the checklist for the text box functionality:

1. Display the text box image in the images folder.
2. Display text that lets the player know if they won or lost.
3. Display text that lets the player retry the level they lost, or move onto the next level if they won.
4. Act as a button to reset or change levels.

Sounds easy enough! But it would be even easier to put all of those elements into their own group. Perhaps the textBoxGroup variable you created in the beginning would be helpful right about now! :]

Paste the following into main.lua and save:

function textBoxScreen(title, message)
	gameListeners("remove");
	
	-- Display text box with win or lose message
	textBox = display.newImage("images/textBox.png");
	textBox.x = 240;
	textBox.y = 160;
	
	-- Win or Lose Text
	conditionDisplay = display.newText(title, 0, 0, "Arial", 38);
	conditionDisplay:setTextColor(255,255,255,255);
	conditionDisplay.xScale = 0.5;
	conditionDisplay.yScale = 0.5;
	conditionDisplay:setReferencePoint(display.CenterReferencePoint);
	conditionDisplay.x = display.contentCenterX;
	conditionDisplay.y = display.contentCenterY - 15;
	
	--Try Again or Congrats Text
	messageText = display.newText(message, 0, 0, "Arial", 24);
	messageText:setTextColor(255,255,255,255);
	messageText.xScale = 0.5;
	messageText.yScale = 0.5;
	messageText:setReferencePoint(display.CenterReferencePoint);
	messageText.x = display.contentCenterX;
	messageText.y = display.contentCenterY + 15;

	-- Add all elements into a new group
	textBoxGroup = display.newGroup();
	textBoxGroup:insert(textBox);
	textBoxGroup:insert(conditionDisplay);
	textBoxGroup:insert(messageText);
	
	-- Make text box interactive
	textBox:addEventListener("tap", restart);
end

This function places a text box sprite near the center of the screen, and sets up some labels on it for the title and message (passed in). It also sets up an event listener to wait for taps (which will call the restart function when one occurs, which you haven't written yet).

Relaunch the app in your simulator, and make your way to level 2!

Now you'll see two different feedback text boxes depending on whether you lost or beat the level.
But wait — there's no way to get rid of the textbox once it's on screen! It sounds like you'll need one more function to wrap up this game.

One Function to Rule them All

The final chunk of code you'll need will determine what to do if the player has won or lost. It's checklist time:

1. If the player wins level 1, go to level 2.
2. If the player wins level 2, tell them they completed the game.
3. If the player loses on level 1, reset the score and replay level 1.
4. If the player loses on level 2, reset the score and replay level 2.
5. If the player completes the game, congratulate them and clean up event listeners.

Judging by the checklist, it's fair to assume you'll need a few if/then statements. Paste the following into main.lua above "main();" and save:

-- See if the player won or lost the level
function restart()
	-- If the player wins level 1, then go to level 2
	if gameEvent == "win" and currentLevel == 1 then
		currentLevel = currentLevel + 1;
		cleanupLevel();
		changeLevel2();
		levelNum.text = tostring("NYC");
	
	-- If the player wins level 2, tell them they won the game
	elseif gameEvent == "win" and currentLevel == 2 then	
		textBoxScreen("  You Survived!", "  Congratulations!");
		gameEvent = "completed";
	
	-- If the player loses level 1, then make them retry level 1 and reset score to 0
	elseif gameEvent == "lose" and currentLevel == 1 then
		cleanupLevel();
		changeLevel1();
	
	-- If the player loses level 2, then make them retry level 2 and reset score to 0
	elseif gameEvent == "lose" and currentLevel == 2 then
		cleanupLevel();
		changeLevel2();
		
	-- If the game has been completed, remove the listener of the text box to free up memory
	elseif gameEvent == "completed" then
		textBox:removeEventListener("tap", restart);
	end
end

This checks to see if the player has won or lost and sets does the appropriate thing (usually changing levels, or restarting the game).

Relaunch the app and start killing those zombies!

And there you have it, a zombie breakout game in two major cities! Look at you, you're now a professional zombie hunter! :]

Where to Go From Here?

Here is the completed source code for the tutorial.

There’s a lot more you can do to make this game more exciting:

• Add more levels and cities with more zombies.
• Add different types of zombies.
• Add animated sprite zombies.
• Add power ups to the bullet.

In addition, if you want to learn more about Corona, there are two more tutorials about Corona on this site that you might enjoy:

• How To Make a Simple Balloon Pop Game with Corona Tutorial
• How To Make a Game Like Jetpack Joyride Using LevelHelper and SpriteHelper [Corona Edition]

Hopefully you will create your own fun Corona games in the future! And if you have any questions or comments about this tutorial or Corona in general, please join the forum discussion below!

This is a post by Tutorial Team Member Greg Pugh, author of the Colin Turtle children's eBook app series. You can also find him on Google+.