# AGENTS.md

This file is the quick-start map for agents working in this repository. Keep it
small and point to the live docs instead of duplicating the whole plan.

## Current Modernization Goal

PanoPainter is being incrementally modernized into independently testable C++23
components while preserving current behavior. OpenGL remains the working backend
until the renderer boundary is proven; Vulkan/Metal/WebGPU work waits behind that
boundary.

Read these first:

- `docs/modernization/roadmap.md` - live phase roadmap, recent results, and next
  work queue.
- `docs/modernization/debt.md` - required debt log. Every temporary adapter,
  retained legacy dependency, skipped platform, fallback, or shortcut needs an
  entry with validation and removal conditions.
- `docs/modernization/capability-map.md` - behavior that must be preserved.
- `docs/modernization/build-inventory.md` - current build/component inventory.
- `docs/adr/0001-modernization-boundaries.md` - component boundary decisions.

## Working Rules

- Work on `codex/modernization-cmake-foundation` unless the user says otherwise.
- Commit and push each verified successful progress slice.
- Prefer larger coherent slices over tiny checkpoints, but keep docs/debt updated
  with each slice.
- After a verified slice is committed and pushed, reset conversation context
  before starting the next slice when practical, especially if the thread is
  approaching automatic compaction. Record all needed resume state in committed
  code/docs first so the next thread can restart from `AGENTS.md`, roadmap/debt,
  and git history instead of relying on chat transcript context.
- Do not revert user changes. Unrelated untracked notes, such as
  `docs/human-review-notes.md`, should be left alone unless explicitly requested.
- Use CMake as the source of truth. Legacy Visual Studio project files are not the
  modernization path.
- Use `apply_patch` for manual source/doc edits.

## Build And Test

Primary Windows configure/build:

```powershell
cmake --preset windows-msvc-default
cmake --build --preset windows-msvc-default --config Debug --target PanoPainter pano_cli
```

Quiet checkpoint validation, preferred when working through Codex token-limited
sessions:

```powershell
powershell -ExecutionPolicy Bypass -File scripts\automation\quiet-validate.ps1 -BuildTargets PanoPainter,pano_cli -TestRegex "pp_app_core|pano_cli_plan"
```

The quiet wrapper writes full command logs under `out/logs/quiet-validation`,
prints only a compact summary, and applies editable warning/noise filters from
`scripts/automation/quiet-validation-ignore.txt`. If a step fails, read the
reported log file instead of rerunning with verbose output.

Focused fast validation:

```powershell
ctest --preset desktop-fast --build-config Debug --output-on-failure
```

Useful targeted pattern:

```powershell
ctest --preset desktop-fast --build-config Debug -R "pp_app_core|pano_cli_plan" --output-on-failure
```

Apple compile validation runs through the Mac mini SSH alias `panopainter-mac`:

```powershell
powershell -ExecutionPolicy Bypass -File scripts\automation\apple-remote-build.ps1 -Presets macos,ios-simulator,ios-device
```

This is a headless component/test/tool compile gate for macOS, iOS simulator,
and iOS device. Signed Apple bundles remain tracked in the debt log.

If MSVC reports corrupt debug information or stale PDB/object errors, clean the
generated build tree target before judging source changes:

```powershell
cmake --build --preset windows-msvc-default --config Debug --target clean
```

## Code Navigation

Codex has a repo-specific skill named `panopainter-code-navigation`. Agents must
use it when necessary: follow this path before broad text search when a task is
about C++ symbol identity, symbol families, declarations/definitions, override
groups, or platform/backend boundaries. Use it when
following C++ symbols, finding symbol families with regular expressions, tracing
service/interface wiring, or checking platform/backend boundary usage.
Reach for `--name-regex`,
`--detail-regex`, or `--path-regex` when looking for generated-style name
families, override groups, command/service families, signatures, or
platform/backend path slices. Use normal `rg` for docs, build files, comments,
string literals, generated command names, or exact non-C++ text.

Prefer compiler-aware navigation when following C++ symbols across the legacy
flat source tree and extracted components:

```powershell
python scripts/dev/clangd_nav.py symbols --file src/app_core/brush_ui.h --name execute_brush
python scripts/dev/clangd_nav.py symbols --file src/app_core/brush_ui.h --name-regex "execute_.*preset"
python scripts/dev/clangd_nav.py symbols --file src/app_core/document_export.h --detail-regex "Export.*Plan"
python scripts/dev/clangd_nav.py definition --file src/node_panel_brush.cpp --line 511 --column 39
python scripts/dev/clangd_nav.py references --file src/app_core/brush_ui.h --line 783 --column 45 --path-regex "src[\\/]app_core"
python scripts/dev/clangd_nav.py self-test
```

The helper talks to `clangd` using an existing `compile_commands.json`. It
defaults to `out/build/windows-clangcl-asan` and then `out/build/android-arm64`;
pass `--compile-commands-dir` or set `PP_CLANGD_COMPILE_COMMANDS_DIR` when using
another Ninja build tree. Use `--name` and `--max-results` to keep output small.
Use `--name-regex` for regex filtering against `qualifiedName`,
`--detail-regex` for symbol detail/signature filtering, and `--path-regex` for
definition/declaration/implementation/reference location filtering. Regex
matching is case-insensitive by default, and `--no-ignore-case` makes it
case-sensitive. Run `python scripts/dev/clangd_nav.py self-test` or the
`panopainter_clangd_nav_regex_self_test` CTest before relying on regex behavior
after tool changes.
Treat symbol, hover, declaration, definition, and implementation lookups as the
reliable path. Reference lookups are riskier because a one-shot clangd process
may not have a complete project index; the helper refuses reference queries
unless callers pass `--background-index` for broader best-effort results or
`--allow-incomplete-references` for explicitly current-translation-unit-only
results. Do not use incomplete reference output as proof that a symbol has no
other users.

## Current Architecture Direction

The desired component split is documented in the roadmap. Current extracted or
in-progress boundaries include:

- `pp_foundation`
- `pp_assets`
- `pp_paint`
- `pp_document`
- `pp_renderer_api`
- `pp_renderer_gl`
- `pp_paint_renderer`
- `pp_app_core`
- `pp_panopainter_ui`
- `pp_platform_*`
- `panopainter_app`

Legacy UI/app code still exists and is being reduced through pure planners,
service interfaces, CLI automation, and CTest coverage. When moving behavior out
of a legacy node, preserve current behavior first, add focused tests, document
remaining shortcuts in `docs/modernization/debt.md`, then wire the live adapter.

## Legacy Context

PanoPainter started as a flat C++17 OpenGL panoramic painting app centered on
singletons such as `App::I`, `Canvas::I`, `Settings`, and `WacomTablet::I`.
Rendering uses GLAD/OpenGL and shaders in `data/shaders/`. UI is XML/Yoga based
with many `Node*` subclasses. Project files are PPI, brush packages are PPBR,
and Photoshop brushes import through ABR support.

Exceptions are disabled in app code. Public modernization APIs should return
explicit status/result objects.