Trait tetra::State

pub trait State<E = TetraError> {
    // Provided methods
    fn update(&mut self, ctx: &mut Context) -> Result<(), E> { ... }
    fn draw(&mut self, ctx: &mut Context) -> Result<(), E> { ... }
    fn event(&mut self, ctx: &mut Context, event: Event) -> Result<(), E> { ... }
}

Implemented by types that contain game state and provide logic for updating it and drawing it to the screen.

Error Handling

The methods on State allow you to return a Result, either explicitly or via the ? operator. If an error is returned, the game will close and the error will be returned from the Context::run call that was used to start it. This allows you to propagate errors back to main for reporting/logging.

The error type defaults to TetraError, but this can be overridden by adding a type parameter to your State implementation (e.g. State<MyError>).

Examples

The hello_world example demonstrates a minimal implementation of the State trait.

The error_handling example demonstrates how custom error types can be used to implement more robust error handling.

Provided Methods

fn update(&mut self, ctx: &mut Context) -> Result<(), E>

Called when it is time for the game to update.

fn draw(&mut self, ctx: &mut Context) -> Result<(), E>

Called when it is time for the game to be drawn.

fn event(&mut self, ctx: &mut Context, event: Event) -> Result<(), E>

Called when a window or input event occurs.

Implementors