68 lines
1.9 KiB
Markdown
68 lines
1.9 KiB
Markdown
# Getting Started
|
|
|
|
Bootstrap the bindings from your game's entry point and drive a frame loop.
|
|
|
|
## Overview
|
|
|
|
The firmware calls a game's single C entry point, `eventHandler`, with a
|
|
`PlaydateAPI*` and an event code. Export it with `@c`, call
|
|
``Playdate/initialize(with:)`` on the first event, and install an update
|
|
callback:
|
|
|
|
```swift
|
|
import CPlaydate
|
|
import PlaydateKit
|
|
|
|
@c(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.refreshRate = 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 a wrapper before
|
|
``Playdate/initialize(with:)`` crashes.
|
|
- **Errors.** Typed throws: ``PlaydateError`` in general,
|
|
``Network/NetError`` for network I/O.
|
|
- **Ownership.** A wrapper that creates a C object frees it on `deinit`;
|
|
keep the wrapper referenced while you use it. Objects vended by the OS
|
|
are not freed by their wrapper; keep the owner alive instead.
|
|
- **Buffers.** Audio callbacks, I/O, the framebuffer, and bitmap pixels use
|
|
`Span`/`MutableSpan`, valid only for the duration of the call.
|
|
- **Threading.** The Playdate runtime is single-threaded, except audio
|
|
callbacks. Do not call the API from other threads.
|