Chapter 2. Managing Scenes and Gideros OOP

Now that we know all the basics, let's create our own game. We will be creating a clone of a Mashballs game, a simple 2D physics puzzler, where the main objective of the game is to drag and launch the main ball in any direction to bounce and hit all other balls on the screen. You can find more information about the game and also download it from: http://jenots.com/mashballs.

We will use Gideros Object Oriented Programming (OOP) and create our own classes, which we will be using throughout the game. As well we will learn to manage multiple scenes and switch between them, and also how to store persistent information for our app.

The following are the topics we will be covering in this chapter:

• Setting up our project

• Introduction to Gideros OOP

• Introduction to scene manager

• Creating your own scenes with Gideros OOP

• Creating a start screen for the game

• Creating an options screen for the game

• Storing persistent information

Setting up our project

Open up Gideros Studio and create a new project. Let's call it MashballsClone. While we are there, let's create the main.lua file for our initial code and also create the images folder to store our images in.

Just to make our project more maintainable, it is better to copy the files of the Gideros project in the same folders as you add them inside Gideros Studio. For example, create the images folder (and any other folder we will be creating) in your filesystem, and before you add images to Gideros project folder, copy them into the corresponding folder and only then add it in Gideros Studio. That way the structure will be the same for both Gideros project and your filesystem.

Now let's do the necessary settings. Right-click on the MashballsClone folder inside the Project pane and select Properties. Click on the iOS tab and select For iPhone and iPad as value for both Retina Display and Autorotation, which means we will support both iPads and iPhones with Retina display...

Creating scenes

Now we should have the main.lua and test.lua files in our project. The first one is empty, and the second one has our experiments with project settings. But note this, if we add some code to main.lua too, the code from both the files (main.lua and test.lua) will be executed. That is because Gideros automatically executes all added Lua files. This might be something new even to experienced Lua developers, as you won't require every file you want to use; and it provides a much more flexible approach in handling projects. But it also has its own limitations.

For example, if all the code is executed automatically, how should we separate different scenes, we want to use in our game, in a better way? Or in what order are the files executed? What if one file depends on another one?

By default, files are executed in the order they were added, but we can assume that the execution order is random and we should not rely on it. The correct way to manage a project is to divide all your...

Summary

We have successfully created the first working scenes of our game. In this chapter we learned how to create Gideros classes, by creating the Button and Settings class. Then we learned how to manage different scenes using Gideros OOP and scene manager. We also learned to use events and store information persistently.

In the next chapter we will start creating the game logic, including managing packs and level loading and unlocking, as well as adding the logic for running the game itself and creating a physics model for our objects.