< All Topics
Print

Unit 3 – The Game Coordinate System


Items In This Unit

 

  • The Game Coordinate System Tutorial

The Game Coordinate System Tutorial

By now you will have seen the game design environment and where you have placed your first (text) object. One important element of game design is understanding the coordinates. Knowing how and where to place your game graphics is key. There are many game engines that you can use and not all use the same coordinate system.

Objects on the scene have an X and a Y coordinate, corresponding to the horizontal position of the X-axis and the vertical on the Y-axis.

In this tutorial, you will learn how GD’s coordinate system works. Follow the steps in the following table to learn more.

Step

Instructions

1

Download the files using the link below:

Coordinate System Files 

2

On your computer, locate the zip file (most likely in your Downloads folder). Unzipping the file should create a folder called “coordinate system”

3

Open GD

4

This time, instead of clicking on “Create a new project” click on “Open a project”

5

Browse to the “coordinate system” and click on game.json inside the same folder.

6

Click on Open after selecting the game.json file. Soon after, you should see the following screen.

7

Click on the Preview button near the top left corner of the GD window.

8

 

 

 

 

Using your keyboard arrow keys, move the small white square to different corners of your game window screen and observe the coordinates indicator found in the centre bottom of your game screen.

Spend a couple of minutes moving the square and then answer these questions by using the coordinates indicator as per above:

  • What happens to coordinates when you scroll left beyond the viewable area of the game?
  • What happens to coordinates when you scroll right beyond the viewable area of the game?
  • What happens to coordinates when you scroll down beyond the viewable area of the game?
  • What happens to coordinates when you scroll up beyond the viewable area of the game?
  • Can you provide a coordinate point that is very close to the centre of the viewable area?
  • Based on your observations, what is the default game resolution of your game window?

Also notice that when you are designing your game, you can see the X and Y coordinates at the bottom left as indicated in the following screenshot.

When you drag and drop objects to your game design area, their base coordinate will be that of the top left-hand corner. This point is often referred to as the origin point. You can change this origin coordinate of an object easily by going to the properties of the object. We will discuss the object origin point in a later lesson.

The little “coordinate system” game you just used was to prove to yourself what the object origin coordinates are during the actual gameplay. Each image or text object you place will have its GD base origin coordinates. The little white square you used was just a small image or game sprite.

Congrats! You have learned the following in this tutorial:

  • How to open an existing GD game
  • How GD coordinate system works
  • The top left corner of the viewable game screen corresponds to coordinate (0,0)
  • Moving down increases the Y part of the coordinate
  • Moving right increases the X part of the coordinate

Next, we will learn about creating an animated text which you can use in your game intros or game end credits.


Game Files/Resources

You can download the files from the link below. 

Download link 

 

Previous Unit 2 – Hello World
Next Unit 4 – Animated Text

Table of Contents