Swift :heart: Playdate

Swift package & plugin for building games that run on Playdate's simulator.

Some things to know:

• Requires XCode 13.3+
• Only tested on M1 Mac.
• Useful for exploring what swift development might be like, you cannot build for device (yet).
• This is highly experimental and likely to change - the swift wrapper is barely started.
• You will likely need to kill the simulator between runs, it doesn't seem to pick up on changes very well.
• The plugin isn't very stable / smart, but it can be made to be.

Usage

swift-playdate can be used via swift-package-manager. It only requires a small bit of project structure.

• Must be a package based project with product type of dynamic.
• Must have a Sources/Resources folder with at least a valid pdxinfo file inside.
  • note: other assets (images, sound, lua files) are to be added here too.
• Builds are handled via SPM:
  • swift package --disable-sandbox pdc: creates a pdx file located at .build/plugins/pdc/outputs/artifacts/{PACKAGE_DISPLAY_NAME}.pdx
  • swift package --disable-sandbox pdc --run: creates a pdx file & opens it in the simulator
  • --disable-sandbox is required because we are using plugins outside their typical reach.
• Ideally swizzle the EventCallback in order to install an update handler.

Example

import Playdate

// MARK: Game Loop

func updateCallback() -> Bool {
  Graphics.clear(with: .white)
  processInputs()
  DisplayList.updateAndDrawSprites()

  return true
}

func processInputs() {
  let state = System.currentButtonState
  player.move(
    by: .init(
      x: state.contains(.left) ? -10 : state.contains(.right) ? 10 : 0,
      y: state.contains(.up) ? -10 : state.contains(.down) ? 10 : 0
    )
  )
}

// MARK: Setup

let image = Bitmap("images/player")
let player = Sprite()

func initialize() {
  setupPlayer()
  setupMenu()
}

func setupPlayer() {
  player.setImage(image)
  player.move(to: .init(x: image.size.width, y: image.size.height))
  player.addToDisplayList()
}

func setupMenu() {
  Menu.addCheckmarkItem("inverted", isOn: false) { isEnabled in
    Display.isInverted = isEnabled
  }
}

// MARK: Event Handler

@_dynamicReplacement(for: EventCallback(event:))
func eventCallback(event: SystemEvent) {
  if event == .initialize {
    initialize()
    System.setUpdateCallback(updateCallback)
  }
}

Supported APIs

Below is a list of all the C apis & wether or not there is some sort of equivalent in Playdate.

Display

File

Graphics

Drawing

Bitmap

BitmapTable

Font

Raw Framebuffer

JSON

Note: it may not be worth implementing these since we have JSONDecoder.

Lua

Scoreboards

Note: these are not documented anywhere.

Sound

TODO

Sprite

System

Menu

Miscellaneous