DIR.Lib

Device-Independent input + Rendering library for .NET. Provides the shared foundation for both GPU (SDL3 + Vulkan) and terminal (Console) applications.

Rendering Primitives

• PointInt — 2D integer point
• RectInt — 2D integer rectangle (upper-left + lower-right)
• RectF32 — 2D float rectangle (x, y, width, height) for pixel-based layout
• RGBAColor32 — 32-bit RGBA color with Lerp, WithAlpha, Luminance
• TextAlign — Near/Center/Far alignment enum
• Renderer<TSurface> — Abstract renderer: FillRectangle, DrawRectangle, FillEllipse, DrawText, MeasureText
• GlyphBitmap — Raw RGBA glyph bitmap with bearing/advance info
• FreeTypeGlyphRasterizer — FreeType2-based glyph rasterizer with COLRv1 color emoji support

Input Handling

• InputKey — Platform-agnostic key codes (letters, digits, function keys, navigation, symbols)
• InputModifier — Modifier flags (Shift, Ctrl, Alt)
• IWidget — Shared interface with HandleKeyDown and HandleMouseWheel for both pixel and terminal widgets

Platform bridges (in downstream packages):

• SdlVulkan.Renderer provides SdlInputMapping (SDL3 Scancode → InputKey)
• Console.Lib provides ConsoleInputMapping (ConsoleKey → InputKey)

Widget System

• IPixelWidget — Extends IWidget with pixel-coordinate hit testing and click dispatch
• PixelWidgetBase<TSurface> — Base class for pixel widgets: clickable regions, text input, buttons, drawing helpers
• PixelLayout + PixelDockStyle — Dock-based layout engine (Top/Bottom/Left/Right/Fill)
• ClickableRegion — Registered during render, walked in reverse for hit testing
• HitResult — Open discriminated union: TextInputHit, ButtonHit, ListItemHit, SlotHit<T>, SliderHit

Text Input

• TextInputState — Single-line text input state machine with cursor, selection, undo
• TextInputKey — Abstract key actions (Backspace, Delete, Left, Right, Home, End, Enter, Escape)
• TextInputRenderer — Renders text input using any Renderer<T> (blinking cursor, selection highlight)
• Callbacks: OnCommit (async), OnCancel, OnTextChanged, OnKeyOverride

Async Operations

• BackgroundTaskTracker — Collects background tasks, checks completions per frame, logs errors via ILogger. Call ProcessCompletions() each frame, DrainAsync() at shutdown.

Usage

using DIR.Lib;

// Rendering
renderer.FillRectangle(rect, new RGBAColor32(0x30, 0x50, 0x90, 0xff));
renderer.DrawText("Hello", fontPath, 14f, white, layout);

// Input handling (SDL3 example)
var key = evt.Key.Scancode.ToInputKey;       // via SdlVulkan.Renderer
var mod = evt.Key.Mod.ToInputModifier;
widget.HandleKeyDown(key, mod);

// Pixel layout
var layout = new PixelLayout(contentRect);
var header = layout.Dock(PixelDockStyle.Top, 28f);
var sidebar = layout.Dock(PixelDockStyle.Left, 200f);
var content = layout.Fill();

// Background tasks
tracker.Run(async () => await SaveAsync(), "Save profile");
if (tracker.ProcessCompletions(logger)) needsRedraw = true;

Dependencies

• SharpAstro.FreeTypeBindings — FreeType2 native bindings
• Microsoft.Extensions.Logging.Abstractions — ILogger interface for BackgroundTaskTracker

License

MIT