reasampler/COMPLETED.md

COMPLETED.md — ReaSampler landed milestones

Completed milestone entries removed from PLAN.md. Each entry preserves its original Goal, Verify, and checklist points with boxes marked done.

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Milestone 0 — Transition scaffold: reaper_mpeview → ReaSampler

Goal: Retire the MPE scaffold and stand up the sampler's pure core in its place, preserving the pure-core / REAPER-shell split. Verify: cmake -B build -S . configures clean; cmake --build build builds the renamed extension target and the pure-core test target; ctest --test-dir build is green with the new bank_model + peaks suites present.

• Delete src/mpe_model.{h,cpp} and src/mpe_view.{h,cpp}; remove tests/test_mpe_model.cpp.
• Rename the CMake project() and the extension MODULE target from reaper_mpeview to reaper_reasampler (binary OUTPUT_NAME likewise); update PREFIX "" / platform SUFFIX blocks to the new target name.
• Replace the pure mpe_model static lib + mpe_model_tests executable with bank_model (pure static lib) + bank_model_tests; keep the CTest wiring.
• Repoint src/main.cpp: drop the mpe_view.h include and all MpeView_* calls (toggle / IsOpen / OnTimer / Cleanup); stub the extension entry so it loads, logs to console, and registers nothing MPE-specific. The command_id / gaccel / hookcommand registration pattern is preserved for reuse (CLAUDE.md §REAPER extension contract) — the MPE action string is removed.
• Choose and record the persistent action-id prefix for the sampler family (replaces CEREBELLUM_MPEVIEW_TOGGLE); this string is forever-stable once shipped (CLAUDE.md §action registration).
• Refresh README.md layout/next-step sections to the sampler module set. (Landed-work reflection is doc-keeper's; this point exists so the stale MPE README does not mislead the first implementer.)

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Milestone 1 — bank_model + JSON round-trip (pure)

Goal: The Sample metadata struct and BankIndex (add / remove / query / tier moves / dedup-by-hash) with JSON serialize/deserialize to std::string. CONTEXT.md §Data model, §Module architecture. Verify: CTest green. Round-trip is lossless (deserialize(serialize(x)) == x) across all fields; dedup-by-hash and tier filtering asserted; relative paths only invariant enforced at the model boundary (no absolute path accepted/stored).

• Define Sample with the full field set (id, display name, relative path, source mode, source range in project time + PPQ, track GUID(s), wet/dry, channels, SR, length sec + beats, capture tempo, optional key, peak/RMS/LUFS, clip flag, tier, content hash, provenance, created ts). CONTEXT.md §Data model.
• BankIndex: ordered collection keyed by id; add / remove / query.
• Hash lookup for dedup-by-content-hash.
• Tier model (scratch | archive) + tier-move + tier filtering; scratch marked auto-prunable.
• JSON serialize/deserialize to/from std::string.
• Tests: full-field round-trip lossless; dedup collapses equal-hash adds; tier filter/move correct; relative-path invariant rejects absolute paths; empty-index and malformed-JSON edge cases.

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Milestone 2 — peaks (pure)

Goal: Compute waveform min/max bins from raw PCM, dependency-free (not REAPER's peak API). CONTEXT.md §Module architecture, §Non-goals. Verify: CTest green. Fed a known signal (full-scale sine, ramp), asserted min/max envelope per bin matches expected within tolerance; channel count preserved; bin count honored for arbitrary sample lengths (incl. remainder bin).

• Min/max bin computation from interleaved PCM given a target bin count.
• Multi-channel handling (per-channel envelope; no silent fold).
• Tests: sine envelope ≈ ±amplitude; ramp envelope monotonic; DC/silence → zero envelope; short-buffer and non-divisible-length edge cases.

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Milestone 3 — Offline capture spike (REAPER shell)

Goal: Offline-render the time-selection master mix to a wav in the project bank folder, add a Sample, log it. The render-driving spike. CONTEXT.md §REAPER API surface (offline render), Build order 3. Verify (in DAW): Render runs via Main_OnCommand(42230) ("Render using most recent settings") — REAPER always shows its offline-render progress window; no stock/header-documented fully-headless path exists. File lands in the project-relative bank folder at 32-bit float WAV at project rate (lossless, dither-free → enables bit-identical/null-test). A Sample is added to the in-memory BankIndex. Non-destructive. Unsaved-project state triggers a Save-As prompt; capture is refused if the user cancels (no default-location fallback). Bit-identical repeats: two identical requests produce byte-identical files. Exact bounds: rendered length matches the requested range (no rounding, no added silence without an explicit tail).

• ICaptureBackend interface + CaptureRequest (source mode, time range, wet/dry, tail, SR/bit-depth/channels, output path). CONTEXT.md §capture.
• OfflineRenderBackend: drive GetSetProjectInfo render settings + GetSetProjectInfo_String file/pattern/format; verify every flag against vendor/reaper-sdk/sdk/reaper_plugin_functions.h.
• Resolve the no-dialog render command/flag on the current REAPER build (open question) and confirm it runs headless.
• Populate a Sample from the finished file; hand to bank_model; console-log.
• Verify bit-identical repeats and exact-bounds by hand on a known range.

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Milestone 4 — persist (index ↔ project ext state)

Goal: Write the BankIndex JSON to project ext state, reload on project open; project-relative path resolution. CONTEXT.md §persist, §Persistence & paths. Verify (in DAW): Index survives Save / Save As / close+reopen; bank travels with the .rpp; relative paths only in the persisted index (Save As to a new folder still resolves the bank).

• SetProjExtState / GetProjExtState under namespace "reasampler".
• Bank-folder resolution from the current project path (EnumProjects / GetProjectPathEx); store under a project-relative subfolder.
• Reload-on-open; confirm survival across Save / Save As.

Notes/decisions:

• Storage: SetProjExtState / GetProjExtState, namespace "reasampler", keys bank_index (serialized JSON) and project_guid; relative paths only in the persisted index.
• Project identity: keyed off a minted GUID stored in ext state (REAPER exposes no native per-project GUID), not the raw ReaProject* — a recycled pointer cannot misread a project switch as a Save-As.
• Save-As: copy semantics (Daniel's decision) — the reasampler_bank/ folder is copied under the new .rpp; the old project's bank stays intact. Every ext-state write calls MarkProjectDirty so captures/GUID changes flush on the normal save.
• Save-As collision — fixed (DAW-verified): project identity is GUID-primary — the stored per-project GUID is the identity of record; a different stored GUID always means a different project (Load its bank), immune to REAPER recycling ReaProject* addresses across close/open. The ReaProject* pointer is a secondary signal that disambiguates the same-GUID case only: a different object with the same GUID = a Save-As fork (Load + re-GUID to diverge); the same object with the same GUID + a new path = a genuine Save-As in progress (relocate bank). This replaced two earlier iterations: GUID-only (mis-detected forks sharing a copied GUID) and pointer-primary (mis-detected reopen/new-project because it ignored the GUID on address recycling). Non-destructive preserved.

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Milestone 5 — bank_panel (docked grid)

Goal: Docked LICE-drawn grid: thumbnails (from peaks), audition, multi-select, keyboard navigation. Reuses the docking setup from the retired mpe_view.cpp. CONTEXT.md §bank_panel. Verify (in DAW): Grid docks; thumbnails render from computed peaks; audition plays selected sample; multi-select + keyboard nav work.

• Docked window + LICE grid render loop.
• Thumbnail draw from peaks bins.
• Audition (play selected sample) + stop.
• Multi-select + keyboard navigation.

Notes/decisions:

• Thumbnail cache: in-memory recompute keyed by (sampleId, drawWidth, bankGeneration); peak bins are NOT persisted alongside the index. Cache is discarded on bank change and rebuilt on next draw. (Closes the PLAN "thumbnail cache" open question.)
• Audition: stock PlayPreview / StopPreview API, read-only — display + select + audition only, never inserts into the arrange. Single stop-funnel ensures a leak-free preview lifecycle. Flagged undocumented assumption: StopPreview detaches the source before returning; mitigated by the single-funnel design. Escalation path if a runtime pop appears: switch to StartPreviewFade + deferred free.

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Milestone 6 — insert (placement)

Goal: "Insert selected sample at edit cursor" via InsertMedia. CONTEXT.md §insert, Build order 6. Verify (in DAW): Selected sample inserts at the edit cursor wrapped in Undo_BeginBlock2 / Undo_EndBlock2; conform-to-tempo is an explicit flag — no silent time-stretch when off.

• InsertMedia(path, mode) at edit cursor (verify mode bits against SDK).
• Conform-to-project-tempo vs literal as an explicit flag (never silent).
• Undo-block wrapping.

Notes/decisions:

• Placement target: inserts the focused bank sample onto the currently selected track(s) at the edit cursor (Daniel's directive — not a new track). Uses InsertMedia base mode 0; for multiple selected tracks the sample is placed on each at the same cursor position, then the original track selection and edit-cursor position are restored — non-destructive to editing state. The entire operation is one undo block.
• No silent time-stretch: the &4 stretch-to-time-selection bit is never set; a pure insert_plan test asserts this across all mode combinations. Conform-to-project-tempo is an explicit separate action (&8), never on the default path.
• Non-destructive to the bank: insert only adds arrange items — no bank/file/ext-state writes.

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D1 — view_mode_model (pure)

Goal: REAPER-free mode registry + membership index + folder-tree-aware visibility derivation + parking/restore planner + JSON round-trip. The heart of the phase; mirror of bank_model. CONTEXT.md §Design View (Module architecture — pure). Verify: CTest green. N-mode model (not a boolean); Arrange + Design seeded. Restore-planner round-trip (snapshot → park → restore) returns every driven flag to its captured value. Parent-derivation correct against a supplied folder tree. JSON round-trip lossless across modes + membership + show-both + snapshots + active mode.

• Mode registry: ordered (id, display name, ordinal); Arrange + Design seeded; add/query more modes (prove N-mode, not binary).
• Membership index: GUID → { mode ids } + per-track show-both flag; add / remove / retag / query; untagged = Arrange.
• Folder-tree-aware visibility derivation: given a supplied parent↔child tree + active mode, compute the visible set (active leaves, derived-visible parents, show-both leaves, master always in).
• Parking/restore planner: emit exact (track, flag, value) op-lists for park and restore from active mode + snapshot record.
• JSON round-trip: modes + membership + show-both + snapshots + active mode.
• Tests: N-mode add/query; parent follows tagged leaf (multi-mode parent); restore-round-trip returns snapshot values (never hardcoded "on"); show-both leaf never parked; unknown/stale GUID tolerated; JSON lossless.

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D2 — view shell (apply flags in the DAW)

Goal: Read the folder tree and drive REAPER flags per the planner. CONTEXT.md §Design View (view shell, REAPER API surface). Verify (in DAW): Toggling active mode hides + parks inactive leaves (B_SHOWINTCP/B_SHOWINMIXER/B_MAINSEND/I_FXEN + per-FX offline) and restores active ones from snapshot. Master untouched. B_MUTE/I_SOLO untouched. Untagged tracks untouched. Parents follow their tagged descendants.

• Build parent↔child tree from I_FOLDERDEPTH; feed to view_mode_model.
• Snapshot prior flag values (GetMediaTrackInfo_Value) before parking.
• Apply park/restore ops (SetMediaTrackInfo_Value for the four flags; TrackFX_GetCount + per-FX TrackFX_SetOffline). Verify flag names/signatures.
• GUID resolution: GetTrackGUID / guidToString / stringToGuid (never index).
• Review gate: no path touches master visibility or B_MUTE/I_SOLO, or any untagged track's owned flags.

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D3 — persist slice (view state ↔ project ext state)

Goal: Serialize the view section into the "reasampler" namespace alongside the bank; reapply the active mode on project open. CONTEXT.md §Design View (persist). Verify (in DAW): Membership + active mode + snapshots survive Save / Save As / close+reopen; on open, the active mode's visibility + processing is reapplied. Saved-while-parked project restores parked tracks from persisted snapshots (not to a guessed "on").

• Serialize/deserialize the view section under "reasampler" (shared blob, distinct section from the bank index).
• Reapply active mode on project open (rebuild tree, run the planner).
• Confirm survival across Save / Save As; snapshot durability across save-while-parked.

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D4 — actions

Goal: Bindable action set for the mode workflow. CONTEXT.md §Design View (actions). Verify (in DAW): Each action registered (bindable in Actions list); toggle + mode-jumps MIDI-bindable; tag/untag acts on the current track selection.

• Toggle active mode (cycle; extensible to cycle-all for >2 modes).
• Activate mode: Arrange / Activate mode: Design (direct jumps).
• Tag selected tracks → Design / → Arrange; Untag selected (= → Arrange).
• Show-both for selected tracks (toggle).
• Register each (command_id/gaccel/hookcommand); toggle + jumps MIDI-bindable.

Notes/decisions:

• New src/actions.{h,cpp} — the Design View action family registered via the command_id/gaccel/hookcommand contract in main.cpp; MIDI-bindable.
• New src/track_guid.{h,cpp} — shared MediaTrack* → canonical GUID-string formatter; used by both the view shell and the actions layer (single source of truth for membership keys).
• Wiring: actions drive the D2 view shell and D3-persisted model; saved active mode is reapplied on project load via a load-signal seam in persist (loadFromProject raises it; main.cpp's timer drains it) — persist stays model-only.
• A pure nextModeId free function added to view_mode_model (the N-mode cycle decision behind "toggle"), unit-tested in the existing view_mode_model_tests.

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D5 — in-window toggle affordance (UI)

Goal: The segmented mode switch in the ReaSampler / bank_panel window header. CONTEXT.md §Design View (UI). Verify (in DAW): Segmented control shows current mode (lit segment), one click flips modes via the D4 toggle action, per-mode membership count visible, offlined-FX caveat surfaced as a tooltip.

• Segmented mode switch [ Arrange | Design ] in the window header; active lit.
• Wire the switch to the toggle/activate actions from D4.
• Per-mode membership count display.
• Offlined-FX re-init caveat as a tooltip on the switch.

Notes/decisions:

• New PURE module src/mode_switch.{h,cpp} — REAPER-free layout math for the Design View mode switch: divides a header rectangle into N equal segments (one per registered mode) and hit-tests a point to a segment. Unit-tested via a new mode_switch_tests CTest target. Mirror of bank_grid.
• src/bank_panel.cpp — segmented [ Arrange | Design ] control drawn in the panel header (one lit segment per registered mode, click activates that mode via view::applyMode), with the grid offset below the header.

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D2-W1 — view_mode_model lane extension (pure)

Goal: Extend D1's pure planner to item level for the two-canvas sub-phase: lane↔mode mapping, a managed-vs-manual lane-ownership index, managed-only item-lane ops in the toggle planner, the "which lanes may this toggle touch" query, the auto-tag decision (manual-lane items exempt; pre-existing ⇒ Arrange), and JSON round-trip of the lane index. REAPER-free, unit-tested; mirror of D1. CONTEXT.md §Two-canvas sub-phase (Module architecture — pure). Verify: CTest green; D1 behavior and tests unchanged.

• Lane↔mode mapping: which lane maps to which mode, which C_LANEPLAYS value per mode.
• Lane-ownership index: per (track GUID, lane) managed-which-mode vs manual; managed-only item-lane op family alongside the existing track-flag op family.
• "Which lanes may this toggle touch" query (managed only) — planner emits lane ops for managed lanes only, never for manual lanes.
• Auto-tag decision (pure): new track/item GUIDs + active mode ⇒ membership writes; manual-lane items exempt; pre-existing ⇒ Arrange.
• JSON round-trip of the lane-ownership index.
• Tests: managed/manual partition; toggle-touches-managed-only; auto-tag exemption for manual-lane items; JSON lossless; D1 behavior/tests unchanged.

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Milestone 7 — capture action family

Goal: Bindable capture actions for master / selected tracks / selected items / razor area, each with wet-dry + tail options. CONTEXT.md §actions, Build order 7. Verify (in DAW): Each action registered (bindable in Actions list), routes to the offline backend, and honors wet/dry + tail. Load-bearing principle: none auto-inserts into the arrange.

• Source resolvers: master mix, selected tracks, selected items, razor area (GetSet_LoopTimeRange, P_RAZOREDITS, CountSelectedMediaItems, etc.).
• Register each as a bindable action (command_id/gaccel/hookcommand).
• Wet-dry + tail options per action.
• Review gate: confirm no capture path touches the timeline.

Notes/decisions:

• Four wet bindable capture actions — master mix, selected tracks, selected items, razor area — registered under the CEREBELLUM_REASAMPLER_CAPTURE_* command-id prefix. Each routes to OfflineRenderBackend (RENDER_* snapshot/restore, dither/normalize off, 32-bit float), produces a Sample, adds it to the bank, persists, and calls MarkProjectDirty. The M3 spike action was retired.
• Wet-only decision (Daniel): REAPER offline render has no true pre-FX "dry" bit — the only wet/dry-adjacent lever (&8192 pre-fader stems) is post-FX. Approximate-dry action variants were removed rather than ship a "dry" that isn't. CaptureRequest.wetDry is retained as the seam for true dry (M10).
• Pure render_settings module maps source mode → RENDER_SETTINGS bits and parses P_RAZOREDITS (union of track-audio areas), unit-tested. No capture path inserts into the arrange (load-bearing gate); non-destructive (selection/razor read-only).

Superseded / reworked (post-landing):

• The four wet source-mode actions (master/tracks/items/razor) were replaced by three FX-scope actions — capture item, capture track, capture master — with range (razor-else-time-selection) inferred orthogonally. This fixed the defect where item captures were rendered through the parent FX chain.
• FX-scope semantics (initial rework): item = item/take FX only; track = item FX + the selected track's own track FX; master = full chain. For item/track, the out-of-scope chain (ancestors + master, plus the item's own track for item scope) is neutralized during the render.
• Master scope subsequently removed: capture is now two scopes — item and track only. CAPTURE_MASTER and CAPTURE_MASTER_REALTIME are retired (to capture the master, render a track instead). The master track is still neutralized as out-of-scope chain for both item and track captures; it is a bypass target, not a capture scope. The realtime backend taps the selected track (track scope only; item realtime deferred).
• FxBypassGuard (RAII): snapshot → neutralize (FX bypassed via I_FXEN; gain zeroed via D_VOL; pan/width/pan-law/mode set to unity via D_PAN/D_WIDTH/D_PANLAW/I_PANMODE) → render → restore. Non-destructive. This guard is the reusable mechanism M8 (realtime backend) and M10 (null-test / true dry) build on.