Game Data Design

This was a series of tweets.

Game Data Design is something I learned best by doing. I’ve released 4 games on the app store (only one is still available). I’ve gotten to a playable game with 4 others. I am by no means an expert but I feel like I’ve learned a lot and now know how it works best for me.

Have a model that holds your data and state. Make it separated from your UI so it changes its own state. Build for serialization (save/open). Write and rewrite in an evolutionary manner. Make the UI an engine that reacts to and drives your model’s data and state.

A good model will ease all scenarios making bugs easier to fix but also the ability to save/resume a game in any state. Practice good naming. Make variable names verbose if that describes them well. Do not reuse terms for unrelated items. Be a bit silly at times.

I start by roughing out a model and to understand state. Understanding data transformations and calculations will suss out player objects vs the model. What holds what, which direction should communication flow. How is a turn kept track of.

This is my current game’s state enumeration:

enum State { 
     case startingGame, 
     win, // network game only 

// My main model variables:

struct GameModel { 
     var players: [Player]
     var state: State 
     //MARK: Potential and Selection Calculated vars 
     var currentSelections: [DiePairing] 
     var gameBoardPotentialKeys: [Int] 
     var availableNumbers: [Int]

Model manipulation and UI interaction

     func isAvailableNumber(_ num: Int) -> Bool 
// MARK: - Mutation for States mutating 
     func rolling() 
     mutating func selectedRoll(_ pairing: [Int]) 
     mutating func stopSelected() 
     mutating func currentPlayerRoll()

// Player turn management
// MARK: Turn Management

     func nextPlayerIndex() -> Int 
     func nextPlayer() -> Player 
     mutating func continueToNextPlayer() 
     mutating func continueSelected() -> Bool 
     mutating func didSomeoneJustWin() -> Player?

// MARK: State Observation

     func isWinningState() -> Bool 
     func isBusted() -> Bool 

I know when the model is changed & how it changes state. It holds an array of Players which encapsulate their own data (If I were on a team more would be private).

// The Player manages its board, potential board & win state. I allow the UI to introspect in to draw.

struct Player { 
     var gameBoard: [Int: Int] 
     var gameBoardPotential: [Int: Int] 
     var hasWon: Bool 
     func winningRowsCount() -> Int 
     func winningRows() -> [Int]

// Then this last bit changes the state of Player

     mutating func addPotentialDie(_ die: Die) { 
     mutating func convertPotential() 
     mutating func convertPotentialToGameBoard() 

Maybe this isn’t the best way but it currently works for me.

Thanks for playing!

I realized after writing that ‘func convertPotential()’ was an exact duplicate and not called. It was more elegant though so I tested it then used that. I should be making a TestFlight build next week for testing. Also all of my structs and enums conform to Codable btw.

Sprite Tour iOS

I’ve updated this somewhat dated Apple example app that really doesn’t seem to be that available anymore (which makes sense since it is from 2013,

It now compiles on Xcode 11. I will probably make a Swift version of this sooner or later.

  • Each scene demonstrates one major concept. You can learn one technique from each sample, then decide which techniques are useful and how to combine them together.
  • APLBasicSprites Shows how to create a default textured or untextured sprite.
  • APLColorizedSprites Shows how to apply a colorization effect to a textured sprite.
  • ColorizedAnimatingSprite Shows animating colorization effect. Originally part of APLColorizedSprites on mac os version.
  • APLResizingSprites Shows how a sprite can be resized, with different scaling effects applied to the texture.
  • APLSpriteAnchors Shows how a sprite’s anchor position can be changed so that the texture image is not centered on the sprite’s position.
  • APLSpriteBlending Shows how an additive blending mode can be used to simulate lights.
  • APLAnimatedSprites Shows how a sprite’s texture image can be animated.