1.9 KiB
1.9 KiB
Getting Started
Bootstrap the bindings from your game's entry point and drive a frame loop.
Overview
A Playdate game has a single C entry point, eventHandler, which the
firmware calls with a PlaydateAPI* and an event code. Export it with
@_cdecl, call Playdate/initialize(with:) on the first event, and
install an update callback:
import CPlaydate
import PlaydateKit
@_cdecl("eventHandler")
func eventHandler(
pointer: UnsafeMutableRawPointer,
event: PDSystemEvent,
argument: UInt32
) -> Int32 {
if case .initialize = SystemEvent(event: event, argument: argument) {
Playdate.initialize(with: pointer) // must happen before anything else
Game.shared.start()
}
return 0
}
final class Game {
nonisolated(unsafe) static let shared = Game()
func start() {
Display.setRefreshRate(50)
System.setUpdateCallback {
self.update()
return true // true = redraw the display this frame
}
}
func update() {
let (_, pushed, _) = System.buttonState
if pushed.contains(.a) {
System.log("A pressed")
}
Graphics.clear(color: .white)
Graphics.drawText("Hello, Playdate", x: 8, y: 8)
System.drawFPS()
}
}
Conventions to know
- Initialization. Calling any wrapper before
Playdate/initialize(with:)is a programmer error and will crash. - Errors. Fallible operations use typed throws —
PlaydateErrorgenerally,Network/NetErrorfor network I/O. - Ownership. A wrapper that creates a C object frees it on
deinit; keep the wrapper referenced for as long as you use it. Wrappers vending OS-owned objects don't free them — keep the owner alive instead, as documented on each API. - Threading. The Playdate runtime is single-threaded; don't call the API from other threads.