Crate retroglyph_core 

retroglyph-core: the no_std-compatible foundation of retroglyph.

Grid, tile, style, color, text, terminal, and event types, plus the Backend trait and the dependency-free Headless test backend, and the App/Flow/Frame game loop contract. Platform backends (retroglyph-crossterm, retroglyph-software) and drawing helpers (retroglyph-widgets) are separate crates that depend on this one.

Architecture

Terminal<B> is the drawing API a game calls into (put, print, layer, …). It owns a double-buffered Grid and diffs the current frame against the previous one in present, sending only changed cells to the Backend. B is the only thing that changes between a headless test and a real window or terminal:

              ┌───────────────────────────┐
              │      App::update(...)      │  game logic, once, generic over B
              └──────────────┬─────────────┘
                             │ put / print / present
                             ▼
              ┌───────────────────────────┐
              │       Terminal<B>          │  double-buffered Grid, cell diff
              └──────────────┬─────────────┘
                             │ draw / draw_layers / poll_event
                             ▼
              ┌───────────────────────────┐
              │      B: Backend            │  the only piece that swaps out
              └──────────────┬─────────────┘
                             │
       ┌─────────────────────┼─────────────────────┐
       ▼                     ▼                      ▼
 Headless (here)      Crossterm                SoftwareRenderer
 in-memory grid,      (retroglyph-crossterm)   (retroglyph-software)
 synthetic events     real TTY, ANSI output    winit window, pixels

Headless stores presented content in memory and lets tests inject synthetic Events with Headless::push_event; nothing here talks to a real terminal or window. Swapping Headless for Crossterm or SoftwareRenderer changes only the B type parameter – App implementations, Terminal calls, and game logic are unchanged. run_blocking drives Terminal<Headless> and Terminal<Crossterm> identically; the software backend’s windowed loop drives Terminal<SoftwareRenderer> through the same App/step contract, inverted because winit owns the event loop instead of handing control back to a driver function.

See examples/headless.rs (cargo run -p retroglyph-core --example headless) for the smallest possible use of Headless, depending on nothing but this crate.

Re-exports

pub use animate::Easing;

pub use animate::Tween;

pub use animate::oscillate;

pub use app::run_blocking;

pub use app::App;

pub use app::Flow;

pub use app::Frame;

pub use app::step;

pub use backend::Backend;

pub use backend::Headless;

pub use camera::Camera;

pub use color::AnsiColor;

pub use color::Color;

pub use color::InvalidAnsiIndex;

pub use event::Event;

pub use event::KeyCode;

pub use event::KeyEvent;

pub use event::KeyEventKind;

pub use event::KeyModifiers;

pub use event::KeyState;

pub use event::MouseButton;

pub use event::MouseEvent;

pub use event::MouseEventKind;

pub use event::PhysicalPos;

pub use event::SystemTheme;

pub use frame_clock::FrameClock;

pub use grid::BlendMode;

pub use grid::Grid;

pub use grid::Pos;

pub use grid::Rect;

pub use grid::Size;

pub use layout::HAlign;

pub use layout::TextLayout;

pub use layout::TextMetrics;

pub use layout::VAlign;

pub use style::Style;

pub use subcell::Glyph;

pub use subcell::quantize_half_block;

pub use subcell::quantize_quadrant;

pub use subcell::quantize_sextant;

pub use terminal::Terminal;

pub use text::Line;

pub use text::Span;

pub use tile::Tile;

Modules

animate

Time-driven value animation: easing curves, a stateful Tween, and a periodic oscillator. Time-driven value animation: Easing curves, a stateful, retargetable Tween, and a periodic oscillate helper.

app

The App-driven game loop. The App-driven game loop.

backend

Pluggable rendering backends. Pluggable rendering backends.

camera

A scrolling viewport into a world larger than the screen. A scrolling viewport into a world larger than the screen.

color

Styling types for character cells.

event

Input event system.

frame_clock

Fixed-timestep accumulator for game loops. Fixed-timestep accumulator.

grid

The layered tile grid: Grid, plus the Size, Pos, and Rect coordinate types used throughout the crate.

layout

Text layout: measurement, word wrapping, and bounded alignment.

style

Text styling: foreground and background color.

subcell

Posterizes small blocks of raw pixels to the best-matching Unicode block-element glyph.

terminal

Stateful terminal management and double-buffering.

text

Styled text primitives: Span and Line.

tile

The atomic drawable unit (glyph, style, sub-cell offsets). Fundamental unit of the grid: a single drawable tile.

Macros

spans

Build a Line from a list of (Style, text) pairs.