rlevo-core 0.1.0

Core traits and types for rlevo (internal crate — use `rlevo` for the full API)
Documentation 
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//! Rendering abstractions for environment visualization.
//!
//! The [`Renderer`] trait is generic over frame type, so ASCII, image, and
//! no-op renderers all share the same interface. Use [`NullRenderer`] when
//! rendering is not required — all calls are eliminated by the compiler.

/// A renderer for environment `E`.
///
/// The associated `Frame` type makes rendering zero-cost when `NullRenderer` is
/// used — `Frame = ()` means no allocation occurs and the call optimises away.
///
/// ASCII text renderers pick `Frame = String`; image renderers pick
/// `Frame = Vec<u8>` or `Frame = image::RgbImage`.
pub trait Renderer<E> {
    /// The output produced by one render call.
    type Frame;

    /// Render the current state of `env` and return a frame.
    fn render(&self, env: &E) -> Self::Frame;
}

/// A no-op renderer with `Frame = ()`.
///
/// Use this as the default renderer type when rendering is not needed.
/// The compiler eliminates all calls at zero runtime cost.
#[derive(Debug, Clone, Copy, Default)]
pub struct NullRenderer;

impl<E> Renderer<E> for NullRenderer {
    type Frame = ();

    fn render(&self, _env: &E) {}
}