4 Platform-specific scripting

Scripting is a fundamental part of game development, as it defines the logic and behavior of game elements. Different platforms and game engines use different languages and methodologies for scripting. In this section, we’ll explore how scripting is done in some of the most popular game engines: Unity, Unreal Engine, Godot, and Construct.

4.1 Unity and C#

4.1.1 Basic Structure of a C Script#

In Unity, C# scripts are components that can be attached to game objects to define their behaviour.

 

Example of a Basic Script in C#:

 

Script Structure:

1. Importing namespaces: ‘using UnityEngine;’
2. Class declaration: ‘public class SimpleScript : MonoBehaviour’
3. Standard methods: ‘Start()’ and ‘Update()’

 

4.1.2 Component Lifecycle in Unity

Components in Unity have a specific lifecycle that determines when their methods are called. The most important methods include:

1. Awake(): Called when the script first instantiates, before ‘Start()’.
2. Start(): Called before the first frame update.
3. Update(): Called once per frame.
4. FixedUpdate(): Called at fixed intervals of time, ideal for physics.
5. LateUpdate(): Called once per frame, after ‘Update()’.
6. OnEnable(): Called when the object is activated.
7. OnDisable(): Called when the object is disabled.
8. OnDestroy(): Called when the object is destroyed.

 

4.1.3 Event Management and User Inputs

Unity provides several ways to handle events and user input, primarily through the ‘Input’ class.

Example of Ticket Management:

4.2 Unreal Engine and Blueprints/C++

4.2.1 Introduction to Blueprints

Blueprints are a visual scripting system in Unreal Engine that allows developers to create game logic without writing C++ code. They use nodes to represent functions, events, and control flows.

Basics:

1. Event Nodes: Trigger actions in response to events (e.g., ‘Event BeginPlay’).
2. Function Nodes: They execute specific actions (e.g. ‘Print String’).
3. Control Flow Nodes: They direct the execution flow (e.g. ‘Branch’).

 

4.2.2 C++ scripting for Unreal

Scripting in C++ offers more control and performance in Unreal Engine. Here’s a basic example of a C++ script. Example of a Script in C++:

4.2.3 Interaction between Blueprints and C++

 

Unreal Engine enables interaction between Blueprints and C++, providing flexibility to combine visual scripting and high-performance programming.

Example of Exposing C++ Functions to Blueprints:

4.3 Godot and GDScript

4.3.1 Basic Structure of a Script in GDScript

GDScript is Godot’s native scripting language, designed to be simple and efficient.

Example of Basic Script in GDScript:

4.3.2 Scenes and Nodes in Godot

Godot uses an architecture based on scenes and nodes. A scene can be anything from an entire level to a single object.

1. Node: Basic unit in Godot that can be a 2D, 3D, GUI, etc.
2. Scene: Collection of nodes organized hierarchically.

 

Example of Scene Creation:

4.3.3 Signal and Event Management

Signals in Godot are an event system that allows communication between nodes.

 

Example of Signs:

4.4 Construct and Event Sheets

4.4.1 Event Sheets Basics

 

Construct uses “Event Sheets” to define game logic through a system of events and actions without the need to write code.

1. Events: Conditions that trigger actions (e.g., “On Start of Layout”).
2. Actions: Operations that are executed when a condition is met (e.g., “Set position”).

 

4.4.2 Event and Action Logic

Event logic in Construct is based on simple “if-then” rules.

Example of Event Sheet:

1. Event: “On Start of Layout”

   – Action: “Create Object” in a specific position.

2. Event: “Every Tick”

   – Action: “Move Object” in one direction.

 

4.4.3 Behavior and Effects Management

Construct allows you to add predefined behaviors to objects to simplify the creation of game logic.

Example of Behaviors:

1. Platform: Adds platform logic to an object.
2. Sine: Adds oscillatory motion to an object.

 

Example of Effect Configuration:

1. Event: “On Collision with Another Object”

   – Action: “Destroy Object” or “Play Sound”.

 

These sections provide a comprehensive overview of how to script on various popular game development platforms, highlighting the specific methodologies and tools for each.