Our Chris is fully in the Game Boy coding flow now. If you need to catch up, Part 1 is here. This week he explains how to create GB sprites and get them into your game!
In this tutorial I am going to look at one of the most important aspects of creating a game. Sprites! Here we will show the tools to create and animate a simple sprite on the Gameboy. With this in your toolset you will be well on your way to making some great games!
Using the Gameboy Tile Designer
I’ve been creating sprites by using a handy utility called ‘The Gameboy Tile Designer’. It’s fairly simple and allows you to choose a colour for your left mouse button and right button to begin paining to the screen.
You can download this utility here.
When you unzip it and open it you will see the following screen:
To assign a colour to a mouse button, have a look at the bottom of the screen. L stands for your left mouse button and R is your right mouse button. Click either and a colour and you can begin to create a design. For this tutorial’s purposes I have created a basic face:
In fact to show some animation. I have created two faces. On the right of the screen, indicated with the red circle you can see numbers. These numbers indicate the different sprites you can create – similar to a Sprite Sheet idea. So in the Second column I have created a slightly different sprite.
These are basic designs but with some work you can do so much more with this utility!
Exporting our Sprite
After creating our artistic masterpiece we need to export this in a format that the Gameboy Development Kit understands. Go to File->Export To
Choose your Filename and path that you want to save your sprite to. Ensure that you save it as type GBDK. The label is important as this is what the code will use to reference the sprite. As we are exporting two images we need to set the From 0 to 1.
One you click the OK button, you should see a header file and a code file in your chosen folder.
Creating the Code
Make sure that the two Sprite files are in the same folder that you are going to save your code in. I have called my .c file ‘Main’ and have created a ‘Make’ file accordingly.
Contents of the Make file
Contents of the Main file
We use the includes that you should be familiar with at the top of the screen as well as including the sprite code file – here called ‘SmilerSprite.c’. Within this file contains the graphical data in the form of an array and also the label – ‘Smiler’.
In our main function we call a method from the Gameboy development kit to load our data from ‘Smiler’ – our variable in the array. Load from the start of the array 0 and load two tiles – 0-1.
Next we load the first sprite into memory, remember we have two sprites in the array so we want the first sprite contained in it (arrays are zero based).
We then move the sprite to a location on the screen.
Finally we make a call to show the sprites on the screen.
This is the code we need to show our first sprite on the screen. Run your make file and place the appropriate Game Boy file in your emulator and run and you should see:
And there you have it! If you’ve followed Chris’ tutorial you can truly say you’re a Game Boy programmer! Well, sort of. Be sure to bookmark our homepage or follow us on social media to find out more!