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Version: 0.7.1

Hello World

Your first UntoldEngine program - logging a message every frame.

Overview​

This tutorial shows you how to add custom code to your game's update loop and log output to the console.

Prerequisites​

This tutorial assumes you have:

  • Created a project using the 'Untold Engine Studiooruntoldengine-create`
  • Opened the project in Xcode
  • Located GameScene.swift in your project

Step 1: Open GameScene.swift​

In Xcode, navigate to:

Sources/YourProjectName/GameScene.swift

Step 2: Add Your First Game Logic​

Find the update(deltaTime:) method in GameScene.swift:

func update(deltaTime: Float) {
    // Skip logic if not in game mode
    if gameMode == false { return }
    
    // Add your custom update logic here
}

Replace the comment with:

func update(deltaTime: Float) {
    // Skip logic if not in game mode
    if gameMode == false { return }
    
    // Your first game code! 🎉
    Logger.log(message: "Hello World! Delta: \(deltaTime)")
}

Step 3: Build and Run​

Press Cmd+R in Xcode.

Open the Debug Console (Cmd+Shift+Y) to see:

Hello World! Delta: 0.016
Hello World! Delta: 0.017
Hello World! Delta: 0.016
...

The message appears every frame! 🚀

What Just Happened?​

The Update Loop​

update(deltaTime:) is called every frame by the engine:

  • 60 FPS = called 60 times per second
  • deltaTime = time since last frame (in seconds)

All game logic goes here: movement, input handling, collision detection, etc.

Logging​

Logger.log(message: "Hello World!")

Use Logger.log() to print debug messages. It's better than print() because:

  • Engine-aware logging
  • Can be filtered/disabled in production
  • Consistent formatting

Other Logging Methods​

Logger.logWarning(message: "Something might be wrong")
Logger.logError(message: "Something went wrong!")

Logging every frame creates spam. Let's log once per second instead:

class GameScene {
    var elapsedTime: Float = 0.0  // Add this property
    
    func update(deltaTime: Float) {
        if gameMode == false { return }
        
        // Accumulate time
        elapsedTime += deltaTime
        
        // Log once per second
        if elapsedTime >= 1.0 {
            Logger.log(message: "Hello World! One second passed.")
            elapsedTime = 0.0  // Reset
        }
    }
}

Now you'll see:

Hello World! One second passed.
Hello World! One second passed.
...

Much cleaner!

Summary​

You've learned:

✅ The update(deltaTime:) method runs every frame
✅ deltaTime is the time between frames
✅ Logger.log() prints messages to the console
✅ How to accumulate time for periodic actions

This is the foundation of game development: write code that runs every frame.