Architecture

ratatui-unity is two halves stitched by a thin C ABI:

• Rust core (src/) — wraps ratatui, maintains terminal state, layouts widgets, rasterizes the resulting buffer of cells into RGBA pixels via fontdue.
• Unity C# bindings (Packages/com.farukcan.ratatui.unity/Runtime/) — calls into the native crate via DllImport, marshals a Texture2D per frame.

Frame Flow

sequenceDiagram
    participant U as Unity (C#)
    participant N as Native (Rust)
    participant R as Ratatui buffer
    participant P as Pixel buffer

    U->>N: BeginFrame()
    N->>R: clear cells
    U->>N: DrawBlock / DrawText / DrawChart ...
    N->>R: enqueue widget commands
    U->>N: EndFrame()
    N->>R: render widgets into cell buffer
    N->>P: rasterize cells (font + colors → RGBA)
    N-->>U: pixel ptr + size
    U->>U: Texture2D.LoadRawTextureData(ptr)

Module Map (Rust)

Module	Responsibility
lib.rs	C ABI exports (ratatui_* functions)
terminal.rs	Terminal lifetime, frame state, command queue
commands.rs	Widget builders the C ABI translates into
renderer.rs	Cell buffer → RGBA pixel pipeline
font.rs	fontdue font cache, glyph rasterization
color.rs	Ratatui Color → RGBA conversion

C# Surface (Unity)

Type	Role
RatatuiTerminal	High-level handle: BeginFrame / Draw* / EndFrame
RatatuiRenderer	Texture management & frame pacing
RatatuiNative	Raw DllImport declarations
CanvasBuilder	Fluent builder for the Canvas widget
ChartBuilder	Fluent builder for Chart widget
Constraint	Layout constraints (Length, Min, Percentage …)
StyledText, ITab	Styling and tabular widget helpers

Memory & Lifetime

• Each RatatuiTerminal owns a Rust-side Terminal allocated by ratatui_terminal_new and freed by ratatui_terminal_free.
• The pixel buffer lives in Rust; C# receives a borrowed pointer per frame and must copy via Texture2D.LoadRawTextureData before the next EndFrame().
• RatatuiTerminal.Dispose() is mandatory — using block or explicit call. Letting the C# object get GC'd without Dispose leaks the Rust terminal.

See the Rust API for the exact extern "C" surface, and the C# API for the wrappers Unity code touches.