Pong | Step-by-step tutorial

The classic game for two players. Each player controls a paddle on each side of the screen. The object of the game is to hit the ball back to your opponent. You score a point if your opponent fails to hit the ball back to you.

This tutorial assumes you have not built a game using Defold before, but have some experience of programming.

• Stage 1: starting a new Defold project.
• Stage 2: importing graphics into the game.
• Stage 3: creating the game objects:
  • 3a: creating player 1's paddle;
  • 3b: creating player 2's paddle;
  • 3c: creating the ball.
• Stage 4: setting keyboard bindings to capture player inputs.
• Stage 5: creating the scripts to move the game objects:
  • 5a: moving player 1's paddle;
  • 5b: moving player 2's paddle;
  • 5c: moving the ball.
• Stage 6: handling objects leaving the screen.
  • 6a: the paddles;
  • 6b: the ball.
• Stage 7: using collision objects to make the ball bounce off the paddles.
  • 7a: creating the collision objects;
  • 7b: creating a script to handle the ball hitting a paddle.
• Stage 8: using a game object to display the score.
  • 8a: creating a font and label;
  • 8b: sending a message from the ball to the score object;
  • 8c: creating a script to update the score.
• Stage 9: adding sound effects.
  • 9a: importing sound files into the game.
  • 9b: creating sound objects.
  • 9c: playing the sounds.
• Stage 10: adding some 'snap'.
• Stage 11: adding some 'crackle'.
• Stage 12: adding some 'pop'.

What you learned in this tutorial

1. The game.project file stores the settings for the game.
   The assets panel is just a handy file explorer. The outline panel actually holds the game objects in the IDE.
2. Sprites are stored in an atlas which is a memory efficient binary store of the image data.
3. A game is built from game objects (go's).
   A game object has components attached to it: sprites, scripts and collision objects.
4. Inputs are bound to actions.
   Actions can be used in scripts to respond to inputs.
5. Lua code called scripts are written in event functions using simple object-oriented techniques.
   Each game object has it's own script that determines it's attributes and methods.
   
6. Collision objects are attached to game objects to give them hit boxes.
   Message passing allows objects to communicate with each other in response to collisions.
7. On-screen text requires a label and font object.
   
8. Sound effects are added to game objects by using sound objects.