# autosample

Graphical interface for automatically recording samples from existing analog audio hardware.

## Build

Requires MSVC (Visual Studio 2019 Build Tools or later) with the Windows SDK and C++20 support.

Open a Developer Command Prompt, then:

```
cl /nologo nob.c
nob.exe debug
build\autosample.exe
```

The first command is a one-time bootstrap. After that, `nob.exe` detects changes to `nob.c` and rebuilds itself automatically. Pass `debug` for a debug build (default is release). Pass `clean` to wipe the build directory.

## Architecture

The project uses a **unity build**: `src/main.cpp` includes all other `.cpp` files, producing a single translation unit compiled with one `$CC` invocation.

### Base layer (`src/base/`)

Foundational types and utilities shared across the project. Provides sized integer/float typedefs (`U8`, `S32`, `F32`, `B32`, etc.), math primitives (`Vec2F32`), string helpers, and arena allocators. This layer has no dependencies beyond the C standard library.

### Platform layer (`src/platform/`)

Abstracts window creation, event polling, and native handles behind a C-style API with opaque `PlatformWindow` handles. The Win32 backend (`platform_win32.cpp`) implements the interface. Other backends can be added without touching the rest of the code.

### UI layer (`src/ui/`)

A thin wrapper around [Clay](https://github.com/nicbarker/clay) (v0.14), a single-header C layout library. Clay uses macros (`CLAY()`, `CLAY_TEXT()`, etc.) for declarative layout with automatic sizing, flex-like child arrangement, and built-in text measurement.

- `ui_core.h` / `ui_core.cpp` — Defines `UI_Context` and `UI_Theme`, handles Clay initialization, lifecycle (`ui_begin_frame` / `ui_end_frame`), text measurement bridge, and error handling. `CLAY_IMPLEMENTATION` is defined here.
- `ui_widgets.h` / `ui_widgets.cpp` — Widget abstractions (currently stubs, reserved for future use).

The application layout is built in `main.cpp` using Clay macros directly. Panel builder functions (`build_browser_panel`, `build_main_panel`, etc.) compose the UI each frame.

### Renderer (`src/renderer/`)

DirectX 12 renderer with a custom SDF-based pipeline for UI rendering. Processes Clay's `Clay_RenderCommandArray` output directly — no intermediate scene graph.

- **Font atlas**: Built at startup using GDI (`TextOutA` into a DIB section), converted to a single-channel R8 texture. Covers ASCII 32–126 (Segoe UI).
- **Text measurement**: GDI-based (`GetTextExtentPoint32A`), exposed to Clay via the `Clay_SetMeasureTextFunction` callback.
- **Render commands**: Handles `RECTANGLE` (SDF rounded rect with corner radius), `BORDER` (individual sides as thin rects), `TEXT` (glyph quads from the font atlas), and `SCISSOR_START`/`SCISSOR_END` (clip regions).
- **Vertex format**: Position, UV, color, rect bounds, corner radius, border thickness, softness, and mode (0 = SDF rect, 1 = textured glyph). Alpha blending with premultiplied SDF anti-aliasing.

### MIDI (`src/midi/`)

Enumerates MIDI input and output devices via the Win32 multimedia API (`midiInGetDevCapsA` / `midiOutGetDevCapsA`). Provides a simple `MidiEngine` with device listing and refresh.

## Project structure

```
nob.c                              Build script (compiled to nob.exe)
nob.h                              nob build system (vendored, single-header)
src/
  main.cpp                         Entry point, unity build includes, Clay layout
  menus.cpp                        Menu bar setup
  theme.cpp                        Theme stub
  base/
    base_core.h                    Sized types, macros
    base_arena.h / .cpp            Arena allocator
    base_math.h                    Vec2, min/max
    base_strings.h / .cpp          String utilities
    base_inc.h / .cpp              Aggregate include/impl
  platform/
    platform.h                     Window management API (platform-agnostic)
    platform_win32.cpp             Win32 implementation
  renderer/
    renderer.h                     Renderer API (graphics-agnostic)
    renderer_dx12.cpp              DirectX 12 implementation, SDF pipeline, font atlas
  ui/
    ui_core.h                      Clay wrapper types and lifecycle API
    ui_core.cpp                    Clay init, text measurement bridge, theme
    ui_widgets.h / .cpp            Widget stubs (reserved)
  midi/
    midi.h                         MIDI device enumeration API
    midi_win32.cpp                 Win32 multimedia implementation
vendor/
  clay/
    clay.h                         Clay v0.14 (modified for MSVC C++ compatibility)
```

### Modifications to `vendor/clay/clay.h`

Two targeted patches for MSVC C++ compatibility:

1. **`CLAY__CONFIG_WRAPPER` bypass** (lines 158–163): MSVC C++ rejects designated initializers inside function-style casts. In C++ mode, the wrapper struct is bypassed: `(type { __VA_ARGS__ })` instead of `(WrapperType { .field = ... }).wrapped`.

2. **Debug view stub** (lines ~3155–3858): Clay's built-in debug view functions use `CLAY__INIT(type) { .field = ... }` directly (not through `CLAY__CONFIG_WRAPPER`), which also fails in MSVC C++. An `#ifdef __cplusplus` guard stubs out the 4 debug view functions as empty no-ops. The debug overlay is not needed.

These patches allow the entire project (including Clay) to compile as a single C++20 translation unit, avoiding C/C++ ABI mismatches with `CLAY_PACKED_ENUM` (which controls enum sizing differently in C vs C++ mode).

## Code style

This project is written in C-style C++. We use `.cpp` files and a small subset of C++ features (default struct values, function overloading, namespaces where useful) but avoid the rest. No classes, no inheritance, limit templates, no exceptions, no RAII, avoid STL containers or algorithms. Data is plain structs. Functions operate on those structs, or pointers to them.

Memory should be managed with arena allocators where possible rather than individual `malloc`/`free` or `new`/`delete` calls. Arenas make allocation fast, avoid fragmentation, and simplify cleanup.

### Syntax style

- Opening braces go on the same line as the function signature (K&R style), not on the next line.
- Use `CAPS_SNAKE_CASE` for constants, `lower_snake_case` for functions and variables, and `CapsCamelCase` for types.

## Dependencies

All dependencies are vendored as source. Nothing to download or install beyond the Windows SDK.

- [nob.h](https://github.com/tsoding/nob.h) — build system
- [Clay](https://github.com/nicbarker/clay) — single-header C layout library (v0.14, with MSVC C++ patches)