# VulkanUI

A walking tour of the V1 widget set. UI-only (no 3D pass), so the entire
visible image comes from one compute dispatch per frame.

## What it shows

- **Layout**: nested `VStack` / `HStack` / `Spacer` / `TabView`, fluent
  builder API, `Length::Px` / `Pct` / `Frac` / `Auto` units, DPI scaling
  (your `Window::scale` flows through automatically).
- **Theming**: `themes::default_dark()` with `theme.primary` / `secondary`
  / `danger` / `input` styles applied per-widget via `.style(...)`.
- **Text**: per-run colour styling via `TextRun`, an em-dash in the
  header to confirm UTF-8 decoding works end-to-end.
- **Buttons**: rounded background (SDF in the shader), centred SDF
  glyphs, `onClick` callbacks. Quit calls `_Exit(0)` so a working click
  visibly closes the window.
- **Progress bar**: a `ProgressBar` at 42 %.
- **TabView**: three tabs (Graphics / Input / Audio); clicking the
  tab bar swaps content.
- **InputField**: focusable text edits with caret blink, UTF-8 typing,
  Backspace / Delete / arrow keys / Home / End, key repeat, horizontal
  scrolling that keeps the caret visible, clipping that prevents
  overflow from drawing past the field's bounds.

## Run

```bash
cd examples/VulkanUI
crafter-build -r
```

## Interactions to try

| Action | Expected |
|---|---|
| Click `Play` / `Options` | Prints `[click] ...` to stderr |
| Click `Quit` | App exits |
| Click a tab label (Graphics / Input / Audio) | Tab body swaps |
| Click an `InputField` | Border turns blue, caret appears and blinks |
| Type | Characters appear at the caret, including multi-byte UTF-8 |
| Hold a letter | After ~500 ms the character starts repeating at ~25 Hz |
| Backspace / Delete | Removes one full UTF-8 codepoint |
| ← / → / Home / End | Moves the caret |
| Type past the right edge | Text scrolls left, caret stays visible |
| Click outside any input | Caret disappears (focus cleared) |

## Notes

The shader (`shaders/ui.comp.glsl` in the library) is compiled to
`ui.comp.spv` next to the binary by the build system.
The font (`Inter.ttf`) is bundled via `cfg.files.push_back`.