reasampler/docs/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.

This file holds the current (1.x) cycle's landed milestones only. For all pre-1.0 (version-0) history, see docs/ARCHIVE.md.

Comment-reduction pass (tree-wide, twelve parallel tracks)

Cut source comment volume tree-wide: 209 files changed, net −6,493 lines. Comment-only lines went from 15,073 to ~8,671, a ~42% cut — before the pass, 37% of all source lines were comment-only. Zero code drift, verified across all 209 files by comparing comment-stripped hashes; the sole intentional exception (Daniel-approved) is two user-facing error strings in src/shell/capture/capture.cpp that lost internal milestone IDs (M8, M3, M7+). Build clean, 61/61 ctest pass. Code review surfaced 2 Major + 8 Minor findings — all content cut that should have survived — and all ten were remediated and re-gated before merge. Driver: Daniel's instruction — "Brief concise engineering comments. A little why, and maybe context, never WHAT."

CMake build-system split (ad-hoc, Daniel's request)

Split the 1423-line root CMakeLists.txt into a 91-line root plus 18 per-directory CMakeLists.txt files under src/, with two shared declaration helpers (reasampler_pure_library, reasampler_test) factored into a new cmake/reasampler_targets.cmake. The root now keeps only repo-global concerns: version/channel single-source-of-truth, configure_file, vendor path vars, LICE_SRC, enable_testing(), and the add_subdirectory calls. Comments throughout were rewritten to the project's comment conventions — phase/wave/ticket IDs removed, module semantics already owned by src/**/CLAUDE.md deleted, load-bearing build facts kept.

Also fixed two duplicate-object-code defects surfaced by the split: 18 core/ translation units were previously compiled directly into the reaper_reasampler module while also being linked in as static libraries — those 18 source entries were removed from the module's source list and 3 missing link edges (view_tree, guid_diff, lane_keys) added so every core/ TU now enters through exactly one static-library link edge. A dead bridge_marshal link edge was also dropped from reaper_reasampler, and two inaccurate comments in src/app/CMakeLists.txt were corrected.

No .cpp, .h, tests/, or vendor/ file was touched. Behaviour is unchanged and was verified mechanically: same 130 targets, same 65 tests all passing, reaper_reasampler.dll byte-identical at 3,477,504 bytes, both channels (stable/beta) building to the same artifact names and locations as before.

Θ-W1-T1 — zone-retirement

ReaSampler 9000's zone-mapping system is retired: one loaded capture, one parameter set, playing across the full keyboard repitched from root with key-tracking — no zones, no per-zone divergence, no keymap of captures. The dedicated zone-editing face and its authoring affordances (add/delete zone, per-zone parameter panel, Low/High/Root zone legend) are gone; the root note survives as a first-class parameter. sampler_core split along the note-routing/per-voice-render responsibility seam (no virtual tick() on the per-voice path), and the Sample face split into chrome/waveform/decks bands with a shared band-stack allocator, discharging the wave's two structural deliverables. Migration adopts a saved multi-zone instance's first zone; single-zone instances lift losslessly.

Deviations from spec:

• The key-range open question ([propose]) is answered outright rather than left open: no key-range concept survives at all — KeyZone/lowNote/highNote are gone from the engine, the write format, and the strip. A low/high pair remains re-addable later as two ordinary parameters. Θ-W2-T3 consumes this decision.
• "Which zone is first" ([verify]) confirmed: PerformanceMap::zones was an ordered vector and Keymap::resolve was first-match-in-order, so index 0 was the audible zone. Migration adopts index 0, and that zone's sampleId supersedes the envelope's stored selectionId.
• The control row (root strip, preview, velocity knob, curve button, Mono|Stereo) moved into the chrome band, directly under the title rather than above the deck — user-visible and deliberate; it's what makes Θ-W2's band-disjointness real.
• Loading a capture now clears the three capture-anchored overrides (root, loop span, start frame) while keeping the shaping parameters — strictly less destructive than the previous whole-zone drop.
• The embed strip became a read-only readout; it lost its click handler since with no zones there is nothing to select.
• Migration side-effect: a previously-zoned instance with implicit channel mode and a stereo capture persisted as Mono will reopen as Stereo. It converges on the documented rule and is reachable only for old blobs, but "sounds identical" was an acceptance bar, so it's a real deviation.
• sampler_core.{h,cpp}'s 956-line documented hot-path exception is retired, not relocated — the tree now carries no over-ceiling exception at all.
• note_entry was deleted as dead code (its only consumer was the removed zone editor).
• Still unverified: a real pre-change project reopening through REAPER's setState has not been exercised in the DAW; migration is proven only in the pure domain against hand-laid legacy bytes.

Θ-W1-T2 — capture-handoff-bugs

Fixed both extension-side capture-handoff defects: drag-out now delivers the capture's audio at the drop target every time (previously intermittent, retry-fixable); dropping a capture onto an FX container now loads the instrument with the capture, matching the FX-button drop path.

Deviations from spec:

• Item 5's root cause was three defects, not one: non-atomic COM refcounts racing a drop target's background copy; an unverified assumption that REAPER had already called OleInitialize on the calling thread; and a teardown-before-payload-check ordering bug that let an unresolvable payload consume the gesture.
• Item 6's fix rests on an unconfirmed hypothesis — that a bare instantiate = -1 left placement to REAPER's ambient FX-chain insert point, which a container-focused chain window moves. It is now pinned to an explicit top-level position; nobody could confirm the mechanism without the DAW.
• The opportunistic rider was partly taken: src/ingest.{h,cpp} re-homed to src/shell/actions/. ext_keys.h was declined (most consumers sit in another track's exclusive surface); resource.h was declined (it's a build input paired with src/resource.rc and the SWELL resgen step).
• Neither acceptance criterion has actually been met yet. Item 5's gate is explicitly a soak ("a single pass is not a gate") and item 6 needs a live container drop; both require REAPER and are outstanding. The code is merged; the acceptance gates are not closed.

Θ-W1-T3 — filter-dsp-port

Lands the per-voice resonant filter as a standalone pure module (core/instrument/engine/filter/, five files: filter_params, filter_coeffs, filter_morph, filter_saturate, voice_filter) — concrete VoiceFilter type, no vtable, no allocation in process(). No call site; Θ-W2-T1 wires it into the voice path.

Deviations from spec — the spec itself changed mid-flight, headline first:

• The Cortex-M4 biquad port was superseded entirely by a TPT/SVF topology, Daniel's call. Measurement found the firmware's high-pass resonance feedback tap vestigial: its stated rationale was inverted (the HP numerator approaches 1 as cutoff falls, not zero — it's the LP numerator that collapses), it reduced HP resonance everywhere it ran, and it carried unwanted sample-rate and input-level dependence. It was a Q15 fixed-point workaround for a ~17-bit cancellation float32 doesn't suffer. Daniel's ruling on the resulting level-dependent resonance bloom: "was a feature on the hardware (one knob colorful HP for master FX), wrong choice for this approach."
• Two discrete modes (HP/LP) became a continuous morph, with two selectable morph laws — HP→BP→LP (default) and HP→notch→LP (Oberheim SEM) — chosen at prepare() via a MorphLaw enum on FilterSettings. Zero per-sample cost, verified by diffing emitted assembly (byte-identical between laws).
• A configurable drive stage was added: an in-loop soft limiter on the band-pass integrator state, normalized 0..1, with a radial dial planned for Θ-W2. Drive at 0 is bit-exact linear.
• Biquad1PoleLP was struck (Daniel's call) and never ported.
• Q spans the full 0.1–10 with √2 at the control centre, replacing the firmware's 0.707-floored mapping — as originally specified.
• No reference sample rate exists anywhere in the module — rate reaches the DSP only via g = tan(π·fc/sr). An interim fix that anchored a feedback tap to a 1/48000 constant was superseded by the rewrite.
• The rewrite fixed a float32 conditioning defect the biquad carried: Direct Form I measured −27% peak error at 20 Hz / 192 kHz; TPT measures +0.034%.
• Still open, deliberately: drive's maximum depth (4.0, set by measurement — at 64 the resonant peak inverted below passband) and the absence of makeup gain both await an ear pass against the real dial.
• The module has no call site — integration is Θ-W2-T1, which also carries three recorded decisions of its own: the envelope-order choice (drive is level-dependent, so pre- vs post-envelope placement is sound-defining), the drive dial's calibration, and the fact that drive authority varies ~11 dB across the morph sweep.

Θ-W2-T1 — filter-voice-path

Wires the pure filter module into ReaSampler 9000's per-voice signal path as a new fixed processing point between the pitch envelope and the amp stage, gives it its own knob-deck group, and relays the deck row in signal-flow order (pitch → filter → amp). Each Voice owns its own VoiceFilter and a second AdsrEnvelope instance — per-voice, never shared — and neither adds allocation or virtual dispatch to the per-sample path. Parameters — morph position, cutoff, Q, drive, mod amount (bipolar ±100%, targeting cutoff), velocity and key-tracking modulation, then AHDSR — live in the one parameter set; FilterParams stores the filter module's own FilterSettings by value rather than a parallel copy of the normalized positions. The filter is off by default and bit-exact off — a project saved before the change reopens sounding identical, pinned by a bit-equality test. ComponentState's params payload moves v8 → v9, appending the filter tail; a v8 blob is a strict prefix and lifts to the off/neutral filter default, with non-finite filter fields falling back to neutral, pinned by a golden byte-literal fixture. Deck composition was extracted into a new pure module core/instrument/ui/deck_groups, with the pitch → filter → amp row order pinned by test; the filter's AHDSR ships as its own FILTER ENV group sibling to FILTER, mirroring the existing PITCH / PITCH ENV split, and a morph-law toggle (Band | Notch) ships as the FILTER group's row toggle.

Deviations from spec:

• An initial mod-quantizer was added, then rejected and removed. A kFilterModSteps = 2048 step gate on the coefficient re-solve stair-stepped the corner (~5.8 cents per step); Daniel rejected it. Replaced by a cutoff-only re-solve (VoiceFilter::setCutoffNorm) that re-derives only g = tan(π·fc/sr) — Q's parabola, the morph's cos/sin, and the folded mix are all cutoff-independent and stay cached from prepare(); filter_params hoists its constant logs. Measured at 48 kHz, Release, net of the sweep generator: kernel alone 2.8 ns/frame, full prepare() 56.9 ns, cutoff-only re-solve 15.5 ns — about 1.2% of a core for 16 continuously-swept voices. The corner now sweeps continuously rather than stair-stepping.
• The editor floor was raised to 840×620, which is also its new default size, up from a 560×460 floor at which the grown deck wrapped to four rows and pushed FILTER ENV / AMP ENVELOPE / VOICE / MASTER off-screen with no scroll. kEditorMinWidth/kEditorMinHeight now live in sample_bands, read by both the shell's checkSizeConstraint and the opening ViewRect. Consequence worth recording: a host with a saved editor rect below 840×620 is clamped up on reopen.

Θ-W2-T2 — stereo-waveform-lanes

Delivered as specified: two stacked lanes, L above R, in stereo mode; one lane in mono; overlays draw once at full stacked height.

Deviations from spec:

• A mono source under stereo mode draws one lane, not two — lane count keys off stereoMode && sourceChannels >= 2, not channel mode alone, since a mono capture in stereo mode is dual-mono and a second lane would be the redundant duplicate the spec forbids. Review confirmed this is the only reading consistent with the decode path.
• The full-height overlay contract Θ-W3 and Θ-W4 consume is type-enforced, not merely documented: an OverlayArea wrapper type that lane rects cannot satisfy.
• A single-slot per-channel PCM cache was added to the editor session, invalidating alongside the existing PCM cache.

Θ-W2-T3 — toolbar-and-piano-strip

Delivered as specified: one toolbar font, no zone-count label, full-width piano strip, uniform key widths, note-name tooltips, root displayed and settable.

Deviations from spec:

• The non-uniform key widths were integer quantisation, not aliasing — the old keyEdgeToX truncated an exact rational, alternating 6px/7px. Θ-W6's general antialiasing audit inherits nothing on key widths as a result, though key edges are still drawn unantialiased.
• Uniform integer key widths and gap-free edge-to-edge tiling are mutually exclusive — 75 white keys do not divide an arbitrary width. The residue now lands in symmetric end gutters, 37px each side at the shipped 840px default — the maximum of a sawtooth with period 75px of window width. Daniel accepted this provisionally, pending how it looks in REAPER.
• The whole control run moved into the toolbar row, not just preview and mono/stereo — the full-width strip left the velocity knob and curve button nowhere else to go.
• Root drag became absolute-tracking rather than pixel-delta, since black keys overlaying white give no single pixels-per-semitone rate.
• Width uniformity is guaranteed in client pixels only. Nothing in the instrument consumes a DPI scale factor, so host-side scaling is unverified — Θ-W6 already carries a "confirm the fix survives DPI scaling" item and now genuinely inherits it.
• A stale-hover latch was fixed across all drag kinds and both drag-termination paths, wider than the strip work that surfaced it.

Θ-W3-T1 — live-parameter-delivery

Continuous playback controls are now delivered live to sounding voices instead of being latched at note-on. New src/core/instrument/engine/live_params.{h,cpp} holds a seqlock-published LiveValues block owned at processor-instance scope, above LoadedInstrument, so live_ and draining_ observe the same one (a drain-slot voice tracks the knob, which is the desired behavior). foldLive(const PlayParams&) is the single derivation from the value type; PlayParams stays a plain copyable value type.

Daniel's two decisions, both implemented:

• Reload tier = Grouping B. Continuous knobs live (filter cutoff/Q/morph/drive/mod amount/key-track; every stage time and level on all three envelopes). Root note, loop span, and start frame still trigger a full reload.
• Mid-stage rule = candidate (iv), hold normalized stage position. φ = elapsed/duration held fixed across a duration change, then advancing at 1/newDuration — expressed over normalized position specifically so Θ-W3-T2's per-segment curve exponent composes with it.

Deviations from spec:

• Trigger's %-length and fades are NOT live — they are baked into SampleData at build, so reload is the only tier that can deliver them. Consequence: a Trigger-mode instance gets zero live amp delivery until Θ-W3-T2 folds the fade pair into the AHD. The five non-live exclusions (kKeyTrack, kFilterVel, kTrigLength, kTrigFadeIn, kTrigFadeOut) are documented in src/core/instrument/ui/deck_groups.h, now their single home.
• Open question 3 resolved as F2 + seqlock; open question 4 (sub-block resolution) was not built but not foreclosed — the writer interface assumes no UI thread; open question 5 verified — a live edit still persists, commitLive keeps the setInstrumentParams write.
• A filter envelope only advances while its depth is non-zero (the exact-skip at modAmount == 0), which is what keeps the at-rest path byte-identical.

Θ-W3-T2 — staged-envelope-curves

Grows the envelope-overlay editor from an amp-only fixture into the shared graphical surface for all three envelopes (amp, pitch, filter): a corner radio switch per deck selects which envelope is overlay-active (none by default, exclusive); every sloped stage on every envelope (Attack/Decay/Release — Hold and Sustain stay flat) gets an editable curve exponent (0.1–10, 1.0 the linear neutral) via a paired inner knob dial and a round mid-segment overlay knot, both resolving through the one curve law in src/core/util/curve_law.h; the pitch envelope becomes AHD (Attack → Hold → Decay, Hold a fraction of the time remaining after Attack and Decay, so A+H+D ≤ span holds by construction, no clamp); AHDSR envelopes get a right-anchored release, dragged from its top node with the bottom-right corner fixed; and the Trigger amp/filter fade-in/fade-out pair is retired in favor of a Trigger AHD, consolidating what were two staged-shape mechanisms into one — item 8's rule (pitch always AHD; amp and filter AHDSR in Gate, AHD in Trigger) governs all three. The Trigger × Preserve end-of-sample click is fixed at its root cause: freezeTail() stopping the pitch shifter's writer a full window before the read head arrives.

Open question resolved — per-mode stage-value state. Gate and Trigger keep SEPARATE stored stage values, on both the amp (PlaySeconds::adsr + PlaySeconds::trigAhd) and the filter (FilterSeconds::env + FilterSeconds::trigEnv). Migration forces it: an old instance carries both an AHDSR and a fade pair, and one shared set cannot preserve both modes' prior sound. Cost: ~160 bytes of persisted state per instance, 6 additional DeckParam ids.

Deviations from spec:

• The migration exponent is FITTED, not neutral — Daniel's explicit ruling, resolving a spec contradiction. PLAN.md stated both "pre-existing instances load at exponent 1.0" and "exponents at whatever reproduces the prior fade shape"; those conflict, and the fix resolves toward the second, since it carries the migration guarantee. Attack lifts at p = 0.6133, decay at q = 1.7437; max deviation from the retired equal-power (sin/cos) fade shape drops from 0.2105 to 0.0875. Every non-migrated curve still lifts to the 1.0 neutral.
• Item 4's fix is deliberately WIDER than spec. The spec scoped the end-of-sample click fix to Trigger × Preserve; the landed fix is not mode-scoped, so Gate × Preserve × source-exhaustion also now rings out (~4 ms) where it previously hard-cut. A held Gate note whose source runs out with no loop is cut at sustain level, landing on the same recycled synthetic tail — scoping the fix to Trigger alone would have knowingly left that click.
• Migration is lossy under a sample-rate mismatch — a documented bound, not a bug. The retired fades were source frames; the lift divides by the project rate while the AHD rebuilds at decode rate, so a rate mismatch shifts migrated stage lengths by that ratio. Documented in the v10 version ladder (component_state_io.h) with a test.
• Payload version is v10. component_state_io.cpp was split on the format seam into component_state_io.cpp + a new params_payload.{h,cpp}.
• New pure module: src/core/util/curve_law.h — the one per-segment curve law (exponent domain, normalized-position→level map, the mid-segment inverse an overlay knot drags through, and the knob's norm↔exponent travel with an exact centre detent). The neutral exponent is a bit-identity. Measured cost of a non-neutral exponent: ~4.7 ns per evaluation, +224 ns/output frame worst case at 16 voices — 3.1% → 4.1% of one core at 44.1 kHz.
• OverlayEnv and the overlay-selection state machine live in core/instrument/ui/deck_groups, not the shell.
• The knot-creation gesture differs from spec. Spec said dragging a segment adds a knot; the landed behavior draws the knot unconditionally on every sloped non-zero segment and responds to a drag within the grab radius. Daniel confirmed this reading stands.
• Loop markers moved from AccentTertiary to AccentSecondary — they collided exactly with the envelope trace (RGB delta 0) in the same overlay rect. Daniel ruled. The palette has since settled: AccentSecondary is #38A8A0 (see the palette-rework entry below and src/core/ui/CLAUDE.md).

Left open by this track, resolved later. The envelope overlay's contrast against the waveform (tertiary purple, measured 1.37:1, below the 3:1 indicator floor) awaited Daniel's eye on a build; pinned as a flagged deviation in tests/test_theme.cpp at the time. Resolved by the ad-hoc palette rework below (91f71f9/a19d645): the trace moved off AccentTertiary onto a new Role::OverlayTrace (#816AA6), clearing the floor at 3.07:1 — the mathematical ceiling for the pairing. See the palette-rework entry below and src/core/ui/CLAUDE.md.

Ξ-W1-T1 — tracking-consolidation

Consolidates the provenance/usage territory into one system: the retired owned_manifest gives way to a new src/core/tracking/ directory holding origin_ledger (the record family — OriginRecord/OriginKind, the insertion-ordered OriginLedger, its JSON codec, and the Fresh/Loaded/Unreadable/FutureVersion load classification) and tracking_authority (the one decision surface: pruneProtection and tiedUsageExists). Both prune's protected set and the resample's replace-vs-add decision are computed from one borrowed TrackingState, so the two safety-critical consumers cannot drift apart. isAbsolutePath was hoisted out to a new src/core/util/relative_path.h, shared with bank_model's Sample.relativePath.

Deviations from spec:

• The deferred persisted-instance-identity fix was not folded in — open question 5 resolved as "restate the deferral." docs/TODO.md already carries the sharpened rationale (the session-epoch candidate and its sibling-drop flaw); not duplicated here.
• sample_usage deliberately stays in core/wire — the consolidation is of the decisions, not the codecs.
• A realtime record interrupted by a project switch strands an untracked WAV in the old project's bank folder. Resolved as document-don't-delete (prune is the exclusive deletion authority); docs/TODO.md carries the entry.
• PruneReport fields were renamed; a malformed ledger is now reported as a distinct blocker with its own recovery instructions.

Ξ-W1-T2 — note-program-model

Lands the programmed-capture-signal model as a new pure module directory, src/core/instrument/note/ — a fourth peer of engine//map//ui/ under core/instrument/ — holding musical_division (the 1/64–64/1 ladder with dotted/triplet multipliers, the 39-entry picker order), tempo (validated BPM plus every beats↔seconds↔ms conversion), and note_program (Velocity, the denominated OffsetAmount, the anchored StartOffset/EndOffset, the NoteProgram record, and resolveNote).

Deviations / resolutions from spec:

• Open question "negative offsets" resolved: both directions are legal and the sign is uniform (positive is later in time); only an inverted window is refused, reported via ResolvedNote::windowCollapsed.
• Open question "denomination seam" confirmed: note length is musical-division-only; the ms/beats duality belongs to the offsets alone. An offset stores the denomination it was entered in, deriving the other view on demand, so a beats offset follows a tempo change and a ms offset holds still.
• Module name/location resolved as src/core/instrument/note/ — three modules, not one, with the layering enforced by the CMake link line.
• Beyond spec: every value type closes its domain at construction behind a single normalizing door (makeDivision, offsetOf, Tempo::fromBpm, Velocity::of), with private value constructors. Consequence: resolveNote needs no failure path and ResolvedNote no validity flag, because every returned field is finite for every constructible program and tempo. Junk detection is relocated to the future codec, which sees both the bytes it read and the value construction produced. NoteProgram deliberately carries no MIDI note number — render pitch is deferred to Ξ-W2 as an additive field.

Palette rework — accent/secondary darkening + overlay/trace role (ad-hoc, Daniel's request)

Two commits (91f71f9, a19d645) resolve the envelope-overlay contrast wart Θ-W3-T2 left open (see above). accent/secondary darkened #84D6D0 → #38A8A0; the keyboard strip's spectral mid stop decoupled from accent/secondary into its own constant, since the darkening had inverted the ramp's lo→mid→hi luminance ordering. A new Role::OverlayTrace (#816AA6) was added and the envelope trace + handles repointed onto it: the trace now measures 3.07:1 against the waveform — the mathematical ceiling for any single color sitting between the primary accent and bg/base (9.41:1 apart; sqrt(9.41) ≈ 3.068), #816AA6 landing at 99.94% of that optimum. Two below-floor pairs remain deliberately accepted — the trace inside the 20%-alpha loop-span fill (2.25:1) and against the waveform's line/hairline zero-line (1.92:1) — both asserted as pinned ranges in tests/test_theme.cpp so either direction of drift fails the build.

Separately: the bank panel's region title enlarged into WCAG large class via a new Font::RegionTitle (19px bold); theme.h's large-text thresholds were corrected (a prior revision had them ~25% low, letting 15px semibold self-classify as Large); compositeOver was added to theme (the composited-fill arithmetic the loop-span-fill contrast pair depends on); and the grabbed envelope handle was repointed off hue onto a size + ring treatment, since no two values that clear the overlay-trace ceiling differ enough to carry a state by color alone.

Full detail — the two-neighbour contrast rule, the WCAG threshold correction, and the accepted below-floor pairs — lives in src/core/ui/CLAUDE.md and docs/product/visual-design-language.md §4 Direction B; not duplicated here.

Θ-W4-T1 — gate-loop-sustain

Establishes loop points as a usable feature and makes a Gate-mode loop function as the sustain — indefinite playback until note-off, with a crossfaded seam. The regression half resolved as present but unreachable, not removed: nothing in any capture path ever wrote Sample::loop, so every capture opened with hasLoop == false; the ghost default parked loopStart at frame 0 directly under the start marker, where markerAtPoint's first-in-draw-order tie-break made the handle ungrabbable; and no crossfade existed at all. Fixed by moving the ghost span to defaultLoopBounds (last quarter of the sample, both handles clear), making a collapsed span the explicit OFF gesture, and adding a parameterized crossfade.

New pure module src/core/instrument/engine/loop/ (loop_span, its own CMake target, its own CLAUDE.md, loop_span_tests) holds resolveLoop, defaultLoopBounds, maxCrossfade, crossfadeWeight, lerpSource, crossfadedSource. Params payload bumped to v11 (kParamsLoopVersion), appended at the tail; slot 12 is reserved for Θ-W4-T2.

Open questions resolved:

• Crossfade units and range. Stored in source FRAMES, not ms — deliberately against the plan's ms lean, because sample_map.h's rule keeps source-timeline quantities in source frames and the seconds path is documented lossy under a sample-rate mismatch. Default 0 frames (a hard seam, which is what makes the migration bar hold by construction); range is the derived [0, min(loopStart, loopEnd − loopStart)].
• Editing surface. The waveform markers, plus a new markerHandleRect top-strip grab tab (top 10px, hit-tested before the full-height marker columns) so markers sharing a frame stay independently grabbable — a general fix for the tie-break defect, not a crossfade special case.
• Crossfade shape. Settled during implementation, not specified in the source doc: linear, not equal-power (correlated taps one loop length apart; no transcendental on the per-sample path), with a decorrelated full-mix/stem exception recorded in the module's own CLAUDE.md.

Deviations from spec / code review:

• Code review found one Major: the crossfade normalizer left an avoidable residual seam discontinuity, and the module's own CLAUDE.md had enshrined that limitation as a mathematical impossibility. Remediated — crossfadeWeight now normalizes over crossfade − 1 so the last rendered frame lands exactly on the incoming tap, the false invariant was corrected, and the seam test now asserts against the material's natural one-frame step rather than a proportionality band. Six review minors were also fixed.
• voice.h sits at ~650 lines after lerpSource/crossfadedSource moved out to loop_span.h — still over the ~600-line ceiling under the standing documented hot-path exception.

Left open by this track, deferred to Daniel (not defects): whether the seam sounds smooth on real material, whether the top-strip tab is discoverable, and the LICE rendering of the tab and crossfade fill. Also open: whether the crossfade default should stay 0 (a smooth seam becomes opt-in).

Θ-W4-T2 — velocity-deck-and-bipolar-curves

Gives the three velocity-curve popups (amp, pitch, filter) one home — a new deck group labelled VELOCITY — and makes the pitch and filter transfer curves bipolar. No velocity-curve button remains in MASTER, PITCH, or Filter. Pitch and filter curves now run y range [−1, 1], default flat at 0, so velocity modulation of pitch and filter is off until the user draws a curve; amp stays unipolar [0, 1] with its flat-unity default unchanged. The domain is modelled as a CurveDomain { Unipolar, Bipolar } field on VelocityCurve, with curveYMin/curveNeutral deriving from it; VelocityPoint::amp was renamed to value. A velocity→pitch transfer curve is new — it did not previously exist. Full scale is kVelocityPitchRangeSemitones = 24.0, now the single constant the shell's pitch-depth control also consumes; it folds into baseRatio_ once at note-on, so process() gains no per-frame work. The preview button's text is replaced by a drawn play triangle — previewGlyph() returns three vertices from the pure layer, the shell passes them to LICE_FillTriangle, which was already in the build: no new dependency, no asset. Params payload is v12 (kParamsVelocityVersion = 12), appending the velocity→pitch curve after Θ-W4-T1's loop block.

Daniel's ruling — the depth knob stays. The implementation initially removed FilterParams::velAmount and the kFilterVel depth knob, arguing a bipolar curve is both shape and amount. Daniel rejected that: the knob scalar AND the curve both apply. The depth control was restored, and the filter's velocity contribution is velAmount × curve.eval(v) with the curve bipolar. Consequence: with velAmount surviving, the pre-v12 migration became a pure domain re-tag — a pre-v12 unipolar curve's y values already sit inside [−1, +1], so velAmount and every knot carry forward bit-identically, with no scaling transform and no version branch in the reader. The earlier fold-and-rescale approach (and its degree-1-homogeneity argument, which was only exact to within double rounding) was removed entirely.

kFilterVel also crossed from non-live to live — a user-visible contract change beyond simple restoration. Rationale: it is a depth over a latched value, the same shape as kFilterKeyTrack, live since Θ-W3; the note latches curve.eval(velocity) and the depth multiply happens in applyLive at block boundaries, gliding through the existing cutoff ramp at zero per-sample cost.

Deviations from spec / code review: Code review ran on two surfaces (engine/persistence, UI/editor) and found one Critical plus two actionable Majors and ten Minors, all remediated. The Critical: editedCurve()'s kNone fallback let Esc-during-a-curve-node-drag write the pitch or filter curve — bipolar domain and all — over the amp gain curve and persist it. Fixed on both routes (the popup close now cancels the drag; the mutable accessor refuses kNone). It has no automated regression pin — src/shell/instrument/ has no test target, and the bug is shell state-machine coupling with no pure-layer equivalent.

Θ-W5-T1 — spline-egs

Ships a free-drawn alternative to every staged envelope: the pitch, filter, and amp EGs can each switch Staged → Spline and have their contour drawn directly on the waveform overlay. The one shared monotone-spline implementation (core/instrument/engine/velocity_curve) gained hard points as a per-segment rule — a hard point does no curve smoothing on either adjacent segment, so the natural sharp angle stands instead of a continuous derivative — and the enhancement flows to every consumer, including the existing velocity→amp transfer curve, with no fork.

• Dual state, save-but-inactive. Both the Staged and Spline state persist simultaneously; switching modes never converts or discards the inactive one, so Staged↔Spline round-trips losslessly. Params payload reached v13; v12 projects still load.
• Gate unavailable in Spline mode. A Spline EG's contour always covers the full sample length as a pure time function (the Trigger/one-shot playback model), so Gate is not selectable while it's active.
• Point-editing grammar converged: left-click adds a point, right-click deletes it, control-click toggles hard/smooth — one grammar shared by both spline consumers (the EG overlay and the velocity-curve popup), matching the popup's already-shipped right-click delete.
• Point-count ceiling: 128 — a musical bound, not a performance one. Segment lookup is an indexed binary search (≤7 steps at 128 points); the cap exists so long rhythmic phrases (roughly two points per articulation event) aren't limited, not because the evaluator is expensive.
• Staged controls disabled while Spline is active — that envelope's segment knobs and their inner curve dials render disabled and reject edits; the dormant staged state is edited only by switching back to Staged.
• The overlay's contour is normalized to the full sample length and drawn 1:1 with the sample's time axis; a different-length capture rescales the stored contour proportionally.

A follow-on change in the same track reworked deck cell width: -1 in cellIds changed meaning from "a blank cell holding geometry" to one cell's width, reserved and redistributed — a Trigger face that drops Sustain and Release now gets wider cells instead of 144 px of dead slots. Group widths, row packing, deck height, and Gate-mode cell widths are unchanged.

Deviations from spec / code review:

• A pure resolveWaveformClaim predicate (core/instrument/ui/spline_edit) now resolves competing waveform-band clicks — contour node, crossfade tab, marker column, staged envelope node — by smallest nominal target area among candidates that actually contain the click, replacing resolution by check order.
• The Gate-unavailable-while-drawn rule was consolidated into enforceGateUnavailableWhileDrawn (core/instrument/engine/play_params.h), now the single home of that rule, called by both resolvePlay and the editor's applyControl.

Θ-W6-T1 — legibility-and-antialiasing

Made the editor legible, then audited every drawn surface for high-DPI clean rendering — sequenced sizing first, audit second, since the audit's disposition list needed a surface that had stopped moving.

• Sizing. Knobs grew 28→40 px (inner curve dial 14→20), the deck cell 48×58→60×74, and the label band 12→16 px, now drawn in Font::Label rather than Font::Micro. Group captions and toggle segments deliberately stay Font::Micro — bumping them would grow the per-group captionWidth reserves, and row 1 has only 14 px of headroom at the floor width.
• Editor default/minimum size 840×620 → 980×680, because the deck cannot pack three rows at the old floor with the wider cells. An existing saved instance's window grows on open. The floor is validated by a derived test rather than literals.
• All 14 time-constant labels now read in ms; internal representation untouched (formatEnvTimeMs is display-only). holdFraction knobs and Len % stay % — they are fractions, not times. The bank panel's clip-length readout is a duration, not a parameter time constant, and stayed out of scope.
• Double-click reset, per ring. Outer ring resets the value, inner dial resets the exponent to 1.0, independently. The window class gained CS_DBLCLKS; WM_RBUTTONDBLCLK was added as its peer so the spline right-click delete survives, and both DBLCLK handlers fall through to the ordinary down handler. The chrome's preview-velocity knob answers reset too, resolving against the drawn circle via a shared inKnobFace rule now used by both the deck and the chrome.
• Antialiasing pass. Fixed: knob track/value arcs (widened to 3 px stacked-radius AA arcs), knob needle (LICE_ThickFLine), inner dial arc and needle, staged envelope slopes, spline contour, velocity-popup trace, waveform outline, preview triangle. Already clean: node handles, curve knots, knob discs, buttons, piano keys, loop markers, borders, gradients, text. The full disposition table is a standing artifact in docs/product/visual-design-language.md §8.
• Three LICE facts the audit established: LICE_Line takes integer endpoints so aa=true still quantizes; LICE_FillTriangle has no aa parameter at all; LICE has no thick-arc call, so a wider ring is stacked 1 px arcs.
• Measured cost: the new AA waveform stroke adds ~0.41 ms per full-grid panel repaint (0.070 → 0.48 ms over a 24-card × 2-band × 136-column grid), ~2.5% of a 60 Hz frame. Recorded in the §8 table and annotated as a one-off scratchpad measurement, not a standing regression guard.
• The piano-key open question is answered: not aliasing. Every key is an axis-aligned integer-width LICE_FillRect, so there was no sloped edge for aliasing to act on; the defect was integer-division residue in the tiling, and W2-T3's fix (remainder moved into symmetric end margins) is arithmetic. Above client-pixel scaling it is unverified — nothing implements IPlugViewContentScaleSupport.

Two structural changes forced by review. The waveform column's vertical arithmetic moved into a pure, unit-tested waveformColumnSpan in core/ui/component_geometry — the first pass had silently broken symmetry about the midline in the shared draw_kit primitive that also feeds the docked bank panel and browse thumbnails. And PlaySeconds plus its AdsrSeconds/ AhdSeconds/PitchEnvSeconds/FilterSeconds companions hoisted out of sample_map.h into a header-only play_seconds INTERFACE target, so the new core/instrument/ui/deck_values module stops transitively linking the bank model and WAV codec. deck_values itself is an extraction of controlValue/ applyControl/resetDeckParam/the ms formatter out of the editor shell, making reset semantics unit-testable; editor_controls.cpp dropped 469→293 lines.

All visual outcomes remain pending Daniel's by-eye sign-off on dev — sizes, arc weight, and whether the waveform stroke improves or thickens the docked panel. Not recorded as accepted.

Θ-W7-T1 — arc-and-spline-aa

Two defects Daniel found by eye once Θ-W6-T1's antialiasing pass shipped — diagnosing both corrected the initial reading of each.

• Arcs never reached opacity. LICE_Arc rasterizes a whole circle clipped per 90° chunk and splits ink across two pixels by the fractional part of the radius; rOuter = radius - 0.5f is half-integer, so no pixel in the ring was ever opaque — measured peak alpha 138/255. The three stacked radii also did not tile: spacing dilates from 1.0 px to 1.41 px at 45°, leaving partial-coverage holes. It read as fuzz, but it was a stroke that never fully inked.
• Splines were fully aliased, not gapped. The apparent dotting was not missing ink: LICE_ThickFLine steps the major axis and structurally cannot gap. The paint loop passed integer cx/cy, so LICE had no sub-pixel position to interpolate — every pixel was full or empty with no AA fringe, and integer cy quantized the slope into an alternating 1/2 px staircase that reads as beading at 100%.
• The cheap fix was rejected. Float endpoints plus LICE_ThickFLine fixes opacity and the staircase, but ThickFLine lays width along the minor axis, so perpendicular weight is wid·cosθ — a measured 42% ripple dipping at every 45° diagonal.
• What landed: one pure analytic thick-stroke rasterizer. Coverage is distance-to-polyline, accumulated with max() into a scratch buffer and blended once — the single blend is what structurally prevents the compositing fringe build-up behind the first defect. An arc is just a polyline, so one code path replaces the stacked arcs, both spline traces, and the two needles. Pure coverage math in a new core/ui/stroke_aa; the blend loop in a new shell/instrument/editor_stroke. shell/panel/draw_kit was deliberately not touched, keeping the docked bank panel and browse cards entirely out of the blast radius.
• Measured, before → after: arc peak alpha 138/255 → 255/255; arc perpendicular weight 1.62–3.24 px (67% ripple) → 2.95–3.11 px (5%); spline weight 1.41–2.00 px (29%) → 1.95–2.01 px (3%). Cost: +0.09 ms per full editor repaint (30 arcs 0.113 → 0.169 ms; 500 px contour 0.013 → 0.047 ms), a knowing regression on an interaction-driven surface, measured in Release against real LICE in an uncommitted harness.
• velocity_curve gained subpixelFromPoint — sub-pixel y was unavoidable since integer cy was the root cause. The existing integer map now rounds the new float map rather than forking a second formula, so hit-testing is unchanged.
• Daniel then ruled that every sub-2 px stroker width be enlarged, because the stroker can only guarantee an opaque core at width >= 2 px (an opaque pixel needs d <= halfWidth − 0.5, and the worst-case pixel-centre-to-centreline distance is 0.5). The knob track arc, the inner-dial needle, and the deck's mini velocity trace all moved 1.0 → 2.0 px. A test pinning the sub-opaque behaviour at 1 px was kept as a guard against reintroduction.
• The audit's method was the root failure, not its output. docs/product/visual-design-language.md §8 had claimed stacked 1 px LICE_Arc calls "keep every ring antialiased" — false. The Θ-W6 audit verified which primitive was called rather than what it rasterized, which is how both surfaces were signed off clean while never producing an opaque pixel. That sentence is deleted, the rows are re-dispositioned with measurements, and the methodological lesson is recorded in §8 as a standing blockquote.

All visual outcomes remain pending Daniel's by-eye sign-off on dev — nothing was verified in a live REAPER window; all measurement was against an offscreen bitmap in a standalone harness. Not recorded as accepted.

Ξ-W2-T1 — resample-bake-chain

The one-click in-sampler resample: dial → bake → dial-again, run without leaving the sampler. A single click renders the dialed sound through the instrument's own voice path, banks the result, re-points the instance at it, and hands the parameter set back neutral — with the recapture's superseded predecessor never deleted, only retired to prune's reclaim pool.

The architecture decision was this track's first deliverable, and Daniel ratified both halves of it. Decision 1 (how the click crosses to the extension) is (1b): the editor invokes the extension's bake action directly over the VST-host bridge — NamedCommandLookup on "_" + channelCommandId(...), then Main_OnCommandEx — so there is no request poller, no nonce, and no cross-process handshake. This dissolves the S13 DEGRADED verdict rather than re-litigating it. Decision 2 (what renders the audio) is (2c): the instrument renders in-process and the extension banks the file — taken over the plan's leaning toward (2a) on an engine-version-skew argument: under (2a) the extension's own copy of the voice engine would render audio the user heard through the VST3's separately-installed copy, and the format ladders do not catch a behavioral divergence between the two. (2c) also leaves the extension's link graph untouched, preserving component_state_io's split-out purpose of keeping engine object code out of the extension.

What shipped:

• New pure modules: src/core/instrument/bake/ — a fifth peer of engine//map// note//ui/ under core/instrument/, holding bake_plan, bake_render, and bake_reset — plus core/model/resample_name and core/wire/bake_wire.
• New shells: shell/instrument/instrument_bake (the instrument's half: render, stage the WAV outside the bank, publish one rsbake_<guid> request, invoke the extension's action synchronously, read the outcome back, adopt + reset) and shell/capture/bake_land (the extension's half: scans every open project tab for pending requests, lands the ones belonging to the loaded project, refuses the rest).
• One new ActionTableRow, RESAMPLE_BAKE, registered through main.cpp's existing data-driven table.
• The instrument's guarded ext-state write surface grew from one prefix (rsusage_) to two (+ rsbake_); the read-only-bank invariant holds because a bake request key is not bank state, and the structural prefix guard still refuses banks/view/tail/assign.

Reset-scope classifications made at review, against Daniel's ratified rule — these parameters were absent from both ratified lists, so the classification itself is this track's durable output:

• Play mode → RESET, to Trigger. The bake's product is a finished one-shot carrying its own attack, span, and release; Gate would re-gate it and re-truncate the printed tail on every iteration, breaking "iteration composes indefinitely." The user-visible consequence: after a bake the instance is in Trigger, and a sustained instrument needs Gate re-dialed by hand.
• Start point → RESET.
• Channel mode and preview velocity → SURVIVE.
• resetAfterBake defaults everything and copies back only the survivors, so a parameter added later resets by default.

Two behaviors worth recording because they are user-visible:

• A bake fired from an instance in a background project tab refuses with BakeStatus::WrongProject rather than risking a write into the wrong project's bank — landing requires three-way agreement between the request's tab, the session's loaded project, and the focused tab.
• A crash-stranded bake request is cleared, not landed, past a 30-second staleness window (kMaxRequestAgeSeconds).
• Extension presence: the resample affordance reads cleanly unavailable, not silently lossy, when the extension is not loaded — bakeAvailable gates the editor's paint state and runBake refuses up front with "resample needs the ReaSampler extension loaded" if asked anyway.

Not demonstrated. Nothing was verified in a live REAPER session. The audible-and-faithful, iteration-composes, save/reload, and arrange-untouched acceptance criteria are structural in the code and untested in a DAW. Three facts remain DAW-unverifiable and are handled defensively rather than asserted: NamedCommandLookup's return on an absent command, Main_OnCommandEx's flag semantics, and whether a WM_TIMER-issued invoke is honoured. Daniel's manual verification is still owed.

Naming and lineage — proposed, not ratified, and still open jointly with Ξ-W1-T1's lineage-record question. This track's proposal: Kick → Kick r2 → Kick r3, incrementing rather than stacking; a replace keeps the source's name; machine-readable lineage rides OriginRecord::parentSampleId, written at birth (landed by Ξ-W1-T1). The proposal is implemented (core/model/resample_name) but not itself a ratified decision.

Deferred, not done — logged to docs/TODO.md: Sample::sourceMode has no value meaning "produced by the instrument" (appending one is a forward-incompatible bank-format change under the current deserializer, which fails the whole bank blob on an out-of-range value — it wants its own decision); and instrument_bake copies the interleaved render buffer into a std::vector<double> for the WAV build, roughly doubling peak memory for a large bake.

Ξ-W3-T1 — capture-signal-popup (spec abandoned by ruling; shipped as derived bake window)

Phase Ξ's final track, and Phase Ξ is now complete. What docs/PLAN.md specified was a popup menu letting the user hand-program the capture signal: note length as a musical-division picker (1/64 to 64/1, dotted and triplet), start/end offsets editable in both ms and beats, velocity, and a preview trigger auditioning the programmed note, under the acceptance criterion "preview and bake cannot diverge."

What shipped instead, and why — the spec and the landed code diverge substantially and deliberately, by Daniel's ruling, not by shortfall. The popup was built (~1500 lines) and then abandoned unmerged. Daniel, verbatim: "I didn't realize you had already derived a usable window. The manual stuff for baking a specific midi length was just an idea, if we have a smarter, fewer-clicks way of doing it, that is ideal. I just don't want to lose anything when we bake. We can abandon the whole parameterized bake window if we can safely derive the window in gate and trigger modes." An audit then established, with executable tests (tests/test_bake_window.cpp), that the window derives losslessly everywhere except one irreducible case. What actually shipped, in src/core/instrument/bake/:

• The bake window derives itself. Trigger derives from the play span; Gate without an active sustain loop derives from source exhaustion + release; Gate with an active loop takes one user value, because a loop sounds for as long as it is held and no derivation can supply a duration.
• One control: "Hold," a musical-division picker in the chrome row, visible and settable only when Gate + an active sustain loop. bakeWindowNeedsHold is the predicate and it reads the ENGINE's loop fold (resolveLoop) rather than the loop fields.
• Velocity comes from the instance's persisted preview velocity, not a hard-coded 100 — three velocity curves are live, so the velocity is a property of the sound being printed.
• No preview trigger, and no popup at all. The chrome-row play button stays a pure MIDI trigger; bake parameters are their own thing. Daniel's ruling: "play button is pure MIDI trigger, Bake parameters are their own thing." So the plan's acceptance criterion 2 ("preview and bake cannot diverge") and its preview-trigger behavior bullet are retired by ruling.
• Three truncation bugs that pre-existed on dev were found and fixed: a drawn EG plus a stale stored %-length lost up to the whole take; the Preserve pitch engine's window closed on the exact frame the terminal declick ramp began, ending files on a full-scale hard cut; and the Gate hold length quantized onto a musical ladder that saturated at 384 beats, cutting any source past it mid-sound (at 120 BPM, anything from 192 s up — a full-mix bounce).
• An invariant was deliberately amended: note/CLAUDE.md's "note length stays musical-division-only" is superseded — a note length now carries EITHER an exact duration (every derived path) or a musical division (the Hold picker only). Quantizing a derived length is what caused the saturation truncation.
• Two undefined-behaviour paths closed as fallout: a NaN keyTrack from a corrupt payload reached a narrowing cast on the per-sample audio path, and a misaligned payload tail could fabricate a value rather than degrade to absent.
• Payload rung v14 consumed (the Hold division).

Not verified in a live REAPER session — worth carrying forward as owed: the "Bake Hold" label fitting its 56 px cell, the Hold knob's duration-ordered travel, and the control's appearance/disappearance on the 500 ms sync tick.

Deferred, not done — logged to docs/TODO.md: the loop intrinsic is folded twice (the editor's pickedMarkers resolves it from the live bank blob first, the processor's reloadInstrument resolves it from the instance ref via resolveCapture), so the two can disagree whenever a bank blob's loop for a capture differs from the copy in the instance's own refs table. Pre-existing — bakeWindowNeedsHold is only a new consumer of pickedMarkers, not the origin of the divergence.