Files
reasampler/docs/PLAN.md
T

202 KiB
Raw Blame History

PLAN

The post-1.0 roadmap. Seventeen queued items consolidated into overlapping areas and sequenced into a Phase → Wave → Track hierarchy that implementation specialists can be dispatched against directly — plus Phase Γ, which did not come from those seventeen (it came from a direct interview, 2026-08-01) and is scoped in docs/product/instrument-control-surface.md, and Phase Ψ, which likewise did not come from the seventeen: it came from a direct list of seven defects and refinements (Daniel, 2026-08-01) and is specified inline in its own section below — there is no backing product doc for it.

What this doc is, and how it relates to the others

  • docs/PLAN.md (this file) — the active on-deck specification list. Each track is written so a specialist brief is writable from this file alone: goal, consolidated source items, surface boundary, behavior, acceptance criteria, open questions, prerequisites.
  • docs/TODO-1.0.md — retained as the verbatim-provenance appendix. It holds Daniel's raw asks and every answer round, unedited; where this plan compresses a behavior bullet, that file is the backing record. Items are cited here by number (e.g. "consolidates items 1, 8, 14"). It is not a work queue any more; this file is.
  • docs/TODO.md — deferred follow-ups with recorded rationale, unrelated to the seventeen (with one flagged intersection: see "Flagged for awareness" below).
  • docs/COMPLETED.md / docs/ARCHIVE.md — doc-keeper's. When a track here finishes, its point is removed from this file and appended to COMPLETED.md with any deviation between landed code and spec noted.
  • docs/product/ — the product-design reasoning behind prior phases. Grep for a cited section rather than reading a file whole.

Worktree slug convention: p<phase>-w<wave>-t<track>-<slug>. Greek phase letters transliterate: Θ → th, Ξ → xi, Γ → g, Ψ → psi. So Θ-W1-T1 dispatches into pth-w1-t1-zone-retirement, Γ-W1-T1 into pg-w1-t1-knob-interaction-law, and Ψ-W1-T1 into ppsi-w1-t1-capture-range-exactness.

Decision state

Everything carried forward from TODO-1.0.md is classified [verify] (answerable by reading code or running the DAW) or [propose] (a design call made at implementation review with a proposal, not a Daniel call); that classification is preserved per question, attached to the track that will answer it.

Θ-W3-T1's two genuine [Daniel] questions — which no amount of code-reading could answer — are both ruled on and the track has landed; see docs/COMPLETED.md for the full narrative. Reload tier = Grouping B (continuous knobs live: filter cutoff/Q/ morph/drive/mod amount/key-track, every envelope stage time and level; 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). Phase Γ opened six [Daniel]-class forks (Γ-F1…Γ-F6) and all six are ruled (Daniel, 2026-08-01) — the rulings are folded into the tracks below and indexed in docs/product/instrument-control-surface.md §8. Γ-F6 closed with a correction to the analysis, not merely a ruling: dynamic reported latency is routine for VST3 instruments and REAPER handles it as a matter of course; what makes the mandated restart expensive here is self-inflicted (setActive(true) calls reloadInstrument), so the cost is ours to reduce and the reduction is filed in docs/TODO.md rather than designed around.

Γ-F3 was subsequently REVERSED and a seventh fork opened AND CLOSED, all by Daniel's later rulings of 2026-08-01. Γ-F3 ("the stage-time ceiling stays 2.0 s") is replaced by "extend the stage lengths to 10s" — the ceiling moves in Γ-W1-T1. Γ-F7 (the VST3 parameter order) is RULED: signal flow"signal flow order." There is now NO unanswered [Daniel]-class question anywhere in this plan.

Ruling 3 (Daniel, 2026-08-01) — real units at the host boundary. "The parameter values exposed to the VST host should be in real units, such that the host automation lanes report usable values." Satisfied through VST3's plain-value layer, not its wire format (which is normalized and cannot be otherwise): toPlain/toNormalized, getParamStringByValue and ParameterInfo::units. Specified at docs/product/parameter-automation.md §6.7 — the per-category unit/precision table, the one-formatter invariant, the stepCount sweep, and the resolution of the apparent conflict with the filter's re-taper prohibition. It lands entirely in Γ-W4-T1 and changes no wave boundary.

Flagged for awareness — not blocking, but decision-grade

  1. Item 15 has an unresolved cross-artifact seam, and it is the phase's largest unknown. The instrument is a read-only bank consumer by invariant (src/shell/instrument/CLAUDE.md), and the one previous attempt at an instrument→extension relay (S13) closed with a DEGRADED spike verdict and was deferred (docs/TODO.md). Resample requires that crossing. Ξ-W2-T1 opens with the architecture decision and this plan names the candidates rather than assuming the deferred relay shape; see that track. Consequence to hold: if every candidate fails verification, item 15's "one click from inside the VST" framing is what gives, not the read-only invariant — the fallback is a bindable extension-side action.

  2. The "Γ before Ξ-W2" ordering is VIOLATED, it was never Daniel's choice, and Γ now owns the correction. Daniel, 2026-08-01: "xi was started before I spun you up, we'll have to correct phase xi inside gamma. wasn't a choice." Ξ-W2-T1 (resample-bake-chain) ran ahead of this plan's sequencing claim, so the bake's settled reset scope — which enumerates parameters by name — ships incomplete: it cannot name rate, pitch offset or the limiter flag, none of which existed when it was written.

    This is no longer a scheduling constraint to honour. It is a correction obligation with a named owner: Γ-W3-T2 bake-reset-amendment. The classification costs no Daniel decision — docs/product/instrument-control-surface.md §3.4 pre-classifies all three against Ξ-W2's own ratified rule (all reset) — but the amendment must be written against what Ξ-W2-T1 actually shipped, not against what this plan predicted it would ship. Ruling 1 adds a second correction of the same shape, homed on Γ-W4-T1 rather than here: see item 3.

  3. The one-way doors are now IN-PHASE, and the sweep for them is a delivered artifact. Ruling 1 (Daniel, 2026-08-01) schedules VST3 parameter reporting inside Phase Γ, as Γ-W4-T1. Everything that participates in a parameter's normalization therefore freezes at the end of this phase rather than at the start of some later one, and anything that ought to move must move first.

    • The taper (Γ-W1-T1) — known, and the reason this phase was ordered as it was.
    • The stage-time ceiling 2.0 → 10.0 s (Γ-W1-T1) — Γ-F3 reversed by Daniel's "extend the stage lengths to 10s." A range endpoint is normalization exactly as much as the curve between the endpoints is.
    • Two further doors that need action, both new, both landing on Γ-W1-T1: every default must have an exact normalized preimage (a host's reset-to-default has no resetDeckParam bypass to use), and the filter's four *Norm controls must not be re-tapered (their laws are already wire-frozen in payload v9).
    • Six more constants freeze without needing to change, and three are already frozen for unrelated reasons; the complete sweep, with dispositions and with what was checked, is docs/product/parameter-automation.md §8. That doc is no longer scoping-only — §§610 are the specification Γ-W4-T1 is built from.

Phase-wide acceptance criteria

These bind every track in all four phases and are stated once here rather than repeated per track. Phase Γ adds a set of its own, stated in its phase header. Phase Ψ adds none — the structural heuristics, performance guardrails, and product invariants below bind it exactly as written (its phase header states its performance posture against the named hot paths).

Structural (root CLAUDE.md, Daniel 2026-07-28)

  • More directories is a must; more files is good; ~600-line file ceiling. The ceiling is the bar; a responsibility seam is the method. Bisection-to-hit-the- number is rejected. sampler_core.cpp (956 lines) is the standing documented hot-path exception — Θ-W1-T1 re-seams it, and any surviving over-ceiling TU must carry the same explicit justification.
  • Templates where earned — compile-time dedup with zero runtime cost, off the hot paths. Not for types that differ in name only.
  • SOLID is great, but saved CPU is better. No dispatch-stack blowouts anywhere; prefer static polymorphism where the types are compile-time-known.

Performance guardrails

Root CLAUDE.md's five extension-side guardrails (peaks envelope compute, audition, realtime-capture tick, JSON, FxBypassGuard) are unchanged by this plan; no track here touches them. The instrument adds a sixth surface that binds every Θ track:

  • process() — the per-voice-per-sample path — takes no new indirection. The filter tick, the envelope evaluation (staged and spline), the pitch-shift read, and the loop read all sit on it. Concrete, inlineable types only: no IEnvelope, no IFilter, no virtual per-voice tick(). A filter with two modes is a branch-predictable switch or a compile-time-known dispatch, never a vtable. Spline evaluation is a binary search over a point array, not a polymorphic curve object.
  • No allocation, no file I/O, no bridge call in process(). The off-audio-thread reloadInstrument + atomic pointer swap stays the only way new state reaches the audio thread. Every new parameter this plan adds follows that path.
  • A split that would add a hot-path indirection is out of scope — rework it or drop it.

Product invariants

  • Capture and placement are separate acts. No track here may place a timeline item. Item 15's bake explicitly must not, and one of its candidate architectures uses a temporary arrange mutation — that candidate must leave the arrange byte-identical.
  • Prune is the single, exclusive file-deletion authority. Item 15's "replace" never deletes bytes; item 17's consolidation may not weaken any protection prune has today.
  • The instrument never writes the bank. Item 15 is the first feature that needs to, and it resolves that by asking the extension, not by breaching the invariant.
  • Migration bar: a project saved before a change reopens sounding identical. Holds everywhere except item 16's genuinely-multi-zone case, where Daniel deliberately relaxed it.
  • Every pure module gets a <module>_tests target that runs without REAPER or a DAW. New pure modules in this plan are not optional-test.

Phase Θ — ReaSampler 9000: one parameter set, a filter, shapeable envelopes, a legible editor

Ships: the instrument with the zone system retired, a resonant HP/LP filter stage in the voice path, curve-shapeable and spline-drawable envelopes on all three EGs, Gate-mode loop sustain, and a re-laid, high-DPI-clean editor — plus the two extension drag/drop defects that block getting captures into it.

Consolidates items 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 16.

All seven waves have landed — Phase Θ is complete. W1 through W7 each carry their own landed note above; see docs/COMPLETED.md for every track's full narrative. Θ-W7 was opened after Θ-W6-T1 shipped, to fix two rendering defects Daniel found by eye; it did not exist in the plan when this phase was originally scoped.

The organizing constraint. Three surfaces in the instrument are single-writer by nature and dictate the wave shape:

  1. The parameter model (zone_params.h + component_state_io) — every parameter addition touches both. Two tracks adding parameters concurrently is a merge fight and two competing ComponentState version bumps.
  2. The voice render path (sampler_core.cpp) — filter insertion, envelope evaluation, loop read, and the Trigger tail all live there.
  3. The Sample face (editor_paint_sample.cpp 516 lines / editor_input_sample.cpp 583 lines) — every UI item repaints it, and both are already at the ceiling.

Parallelism in this phase therefore comes from splitting the Sample face into bands (done once, in Θ-W1-T1) and from extension-side work being genuinely disjoint — not from running two parameter-model tracks at once. Where a wave has one track, the collision is real and the serialization is the correct answer.


Θ-W1 — Collapse and re-seam

All three tracks have landed — Θ-W1-T1 (zone-retirement), Θ-W1-T2 (capture-handoff-bugs), and Θ-W1-T3 (filter-dsp-port) — see docs/COMPLETED.md for the full narrative of each. Between them: the zone subsystem is retired, the wave's two responsibility seams (the sampler_core split, the Sample-face band split) are in place, the two extension-side capture-handoff defects are fixed, and the filter DSP has landed as a standalone pure module — Θ-W2-T1 has since wired it into the voice path (see below).


Θ-W2 — Filter in the voice path; waveform and chrome bands

Depends on W1 for: the one-parameter-set model and the sampler_core seam that T1 writes the filter into; the filter module T1 wires up; the Sample-face band split and band-stack allocator that T2 and T3 fill; and W1-T1's key-range answer, which decides what T3's piano strip displays. Authoring any of this against the per-zone model means writing storage plumbing W1 deletes.

All three tracks have landed — Θ-W2-T1 (filter-voice-path), Θ-W2-T2 (stereo-waveform-lanes), and Θ-W2-T3 (toolbar-and-piano-strip) — see docs/COMPLETED.md for the full narrative of each. Between them: the filter sits in the per-voice signal path with its own deck, the waveform band shows both channels in stereo mode behind a type-enforced full-height overlay contract, and the chrome band's toolbar and piano strip are cleaned up per spec. The three tracks were disjoint by band — T1 owned the parameter model and the deck band, T2 owned the waveform band, T3 the chrome band — and none re-allocated the band stack.


Θ-W3 — Live parameters, then the staged envelope system

Depends on W2 for: the filter envelope's existence — items 1, 8, and 14 govern three envelopes, and the filter is the third; and for the Filter deck, which must exist before it can receive a corner radio switch and inner curve dials. T1 additionally depends on W2-T1 for the filter itself: the filter is the first control set where the latched-at-note-on delivery model fails audibly, and it is what made the defect visible.

Both tracks have landed — Θ-W3-T1 (live-parameter-delivery) and Θ-W3-T2 (staged-envelope-curves) — see docs/COMPLETED.md for the full narrative of each. Between them: every continuous playback control (filter cutoff/Q/morph/drive/mod amount/key-track, every stage time and level on all three envelopes) now reaches a sounding voice live instead of latching at note-on, and the envelope-overlay editor grew from an amp-only fixture into the shared graphical surface for all three envelopes — a corner radio switch per deck (none active by default), curve-shapeable segments on every sloped stage (0.110 exponent, an inner dial paired with an overlay knot), the release-right-anchored AHDSR layout against the pitch envelope's 1:1 AHD, and the Trigger amp/filter fade pair folded into a Trigger AHD, consolidating what were two staged-shape mechanisms into one. The Trigger × Preserve end-of-sample click is fixed; the landed fix is wider than scoped, also ringing out Gate × Preserve × source-exhaustion, previously a hard cut. The ordering was deliberately serial — T1's live-delivery mechanism landed first so T2's new curve exponents and Trigger AHD fields were authored directly into it rather than backfilled afterward.


Θ-W4 — Loop sustain and the velocity deck

Depends on W3 for: the envelope system both tracks compose with — T1's loop-sustain is the Gate-mode sustain the AHDSR releases out of, and T2's bipolar pitch/filter curves modulate targets whose envelopes W3 just reshaped. T2 additionally depends on W2-T1 for the filter's existence and on W2-T3 for the preview button's toolbar position.

Both tracks have landed — Θ-W4-T1 (gate-loop-sustain) and Θ-W4-T2 (velocity-deck-and-bipolar-curves) — see docs/COMPLETED.md for the full narrative of each. Between them: loop points are now a usable feature, with a Gate-mode loop acting as the sustain and a parameterized crossfade at the seam; and the three velocity-curve popups (amp, pitch, filter) now live together in a new VELOCITY deck group, with the pitch and filter curves bipolar and flat-by-default so their modulation is off until drawn, while the amp curve stays unipolar and unchanged, and the preview button's text is replaced by a drawn play-triangle glyph. Params payload reached v11 with T1's loop block and v12 with T2's velocity→pitch curve appended after it.


Θ-W5 — Spline EGs

Depends on W4 for: the bipolar velocity-curve domain (W4-T2) — the spline algorithm is singly implemented and multi-referenced, so its enhancement must land against the final consumer set, and the last consumer to change domain is the pitch/filter velocity curve; and for the Gate-mode loop (W4-T1), since "Gate is unavailable in Spline mode" is only a real, testable rule once Gate has something to be unavailable for. It also depends on W3's radio switch, which is how a spline contour reaches the overlay at all.

Θ-W5-T1 has landedspline-egs — see docs/COMPLETED.md for the full narrative. It shipped a free-drawn alternative to every staged envelope: pitch, filter, and amp EGs can switch Staged → Spline and have their contour drawn directly on the waveform overlay. The one shared monotone-spline implementation gained hard points — sharp corners, no smoothing on either adjacent segment — flowing to every consumer including the existing velocity→amp transfer curve, no fork. Both Staged and Spline state persist simultaneously (saved-but-inactive, lossless round-trip); params payload reached v13, and v12 projects still load. Gate is unavailable while a Spline EG is active; the contour is a pure time function over the full sample length, normalized and drawn 1:1 with the sample's time axis. Point grammar converged on left-click add / right-click delete / control-click hard-smooth toggle, one grammar across both spline consumers. Staged segment knobs and their inner curve dials render disabled and reject edits while Spline is active. Point-count ceiling: 128, a musical bound rather than a performance one. A follow-on change in the same track reworked deck cell width: -1 in cellIds now means one cell's width, reserved and redistributed, rather than a blank cell holding geometry — a Trigger face that drops Sustain and Release gets wider cells instead of dead slots; group widths, row packing, deck height, and Gate-mode cell widths are unchanged.


Θ-W6 — Editor legibility pass

Depends on W5 for: the last change to a drawn surface. Item 13 is an audit whose output is a disposition list over "every class of drawn surface," and item 10's sizing pass is judged by eye over the finished layout — running either while the spline contour, the disabled-knob state, or the deck inventory was still moving would have meant auditing and then re-auditing. Θ-W5-T1 has landed (see docs/COMPLETED.md), so that surface has stopped moving and this dependency is satisfied. The source doc names this sequencing as an observation (item 13 after the layout/knob work); this plan adopts it as the boundary.

One track. Both items repaint essentially every surface in the editor; concurrent tracks would collide everywhere.

Θ-W6-T1 has landedlegibility-and-antialiasing — see docs/COMPLETED.md for the full narrative. It shipped both halves together: 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 stayed Font::Micro, since bumping them would outgrow row 1's headroom at the floor width. The editor's default/minimum size grew 840×620→980×680 to fit the wider deck at floor width; an existing saved instance's window grows on open, and the floor is validated by a derived test rather than literals. All fourteen time-constant labels now read in ms (display-only; internal representation untouched) — holdFraction knobs, Len %, and the bank panel's duration readout stayed out of scope. Double-click resets each ring independently — outer ring resets the value, inner dial resets the exponent to 1.0 — reaching the chrome's preview-velocity knob too via a shared inKnobFace rule.

The antialiasing audit fixed knob arcs and needle, the inner dial arc and needle, staged and spline envelope slopes, the spline contour, the velocity-popup trace, the waveform outline, and the preview triangle; node handles, curve knots, knob discs, buttons, piano keys, loop markers, borders, gradients, and text were already clean. The disposition table is a standing artifact in docs/product/visual-design-language.md §8. The piano-key open question is answered: not aliasing — every key is an axis-aligned LICE_FillRect, so the earlier width defect was integer-division residue in the tiling, not a sloped edge. High-DPI host scaling itself is unverified (deferred, see docs/TODO.md).

All visual outcomes remain pending Daniel's by-eye sign-off on dev.


Θ-W7 — Arc-and-spline antialiasing fix

Depends on W6 for: a drawn surface to find a defect on — this wave did not exist in the plan; it was opened after Daniel found two rendering defects by eye once Θ-W6-T1 shipped, so the audit's own output is what surfaced them.

One track.

Θ-W7-T1 has landedarc-and-spline-aa — see docs/COMPLETED.md for the full narrative. The stacked-LICE_Arc knob and dial rings never reached an opaque core (peak alpha measured 138/255), and the staged/spline envelope and velocity-curve traces were fully aliased rather than gapped, from integer cy quantizing the slope. Both defects, plus the two needles, now route through one pure analytic thick-stroke rasterizer — coverage in a new core/ui/stroke_aa, the single LICE blend in a new shell/instrument/editor_stroke — replacing LICE_Arc and LICE_ThickFLine outright. Measured: arc peak alpha 138/255 → 255/255, arc perpendicular-weight ripple 67% → 5%, spline weight ripple 29% → 3%, at a cost of +0.09 ms per full editor repaint. Daniel then ruled every sub-2 px stroker width up to 2 px, since the stroker only guarantees an opaque core at width ≥ 2 px; the knob track arc, the inner-dial needle, and the deck's mini velocity trace each moved 1.0 → 2.0 px. docs/product/visual-design-language.md §8 is corrected — a false "keeps every ring antialiased" claim is deleted, the rows are re-dispositioned with measurements, and the audit's methodological lesson (verifying which primitive was called is not verifying what it rasterized) is recorded as a standing blockquote. All visual outcomes remain pending Daniel's by-eye sign-off on dev.


Phase Ξ — The resample loop

Ships: one consolidated, fully robust provenance/usage tracking system, and on top of it the one-click in-sampler resample — dial → bake → dial again, with the bank as the medium each iteration passes through.

Consolidates items 15, 17.

Why these two and not more. Item 17 is a prerequisite of meaning for item 15's bank-side half: the replace-vs-add rule is "does provenance-tied usage exist," which denotes nothing until the consolidated lineage records exist. Item 17 is otherwise independent of the editor chain — which is what makes Ξ-W1 concurrency-safe with Θ.

Ξ-W2 onward requires Phase Θ complete. Item 15 presupposes the processing surface it bakes — "filtering, pitching, amp all set up nice" is the instrument items 1, 2, 3, and 14 build — and its settled reset scope enumerates the filter parameters, the spline contours, and the loop points by name. Baking a processing chain that does not exist yet is not a schedule preference; the feature is not expressible. Phase Θ landed as of Θ-W7-T1 (see docs/COMPLETED.md); this gate is satisfied.


Ξ-W1 — Consolidated tracking, and the programmed-note model

Ξ-W1-T1 — tracking-consolidation

Landed — see docs/COMPLETED.md for the full narrative. The provenance/usage territory is now one system: a new src/core/tracking/ directory holds 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), retiring core/model/owned_manifest. 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. sample_usage deliberately stays in core/wire — the consolidation is of the decisions, not the codecs. The deferred persisted-instance-identity fix was not folded in — the deferral is restated in docs/TODO.md, its one home. This track landed OriginRecord's birth-time parentSampleId chain as the lineage mechanism, but Ξ-W2-T1's "naming and lineage" open question (jointly held with this track) is unaffected and still theirs to close — display naming and user-readable iteration lineage were not decided here.

Ξ-W1-T2 — note-program-model

Landed — see docs/COMPLETED.md for the full narrative. The programmed-capture- signal model is a new pure module directory, src/core/instrument/note/ — a fourth peer of engine//map//ui/ under core/instrument/ — holding musical_division, tempo, and note_program (Velocity, the denominated OffsetAmount, the anchored StartOffset/EndOffset, NoteProgram, resolveNote). Both open questions below are answered, for Ξ-W3-T1: negative offsets are legal in both directions (sign uniform, positive is later in time; only an inverted window is refused, reported via ResolvedNote::windowCollapsed), and the denomination seam is confirmed — note length stays musical-division-only, and an offset stores the denomination it was entered in.


Ξ-W2 — The bake chain

Depends on Ξ-W1 for: the consolidated lineage records that make replace-vs-add computable (T1) and the programmed-note record the offline pass renders (T2). Also depends on all of Phase Θ — see the phase note above.

This wave ran AHEAD of Phase Γ, and that was not a choice. The plan asserted Γ must land first so the bake's reset list would be complete on the day it shipped; Ξ-W2-T1 was already live. The consequence is owned, not absorbed: Γ-W3-T2 bake-reset-amendment completes the list afterwards, and Γ-W4-T1 adds the host-notification obligation once parameters exist. Neither is this wave's work, and neither is a defect report against it.

One track. The bake is one gesture and one chain; the architecture decision at its head governs every step after it.

Ξ-W2-T1 — resample-bake-chain

Landed — see docs/COMPLETED.md for the full narrative. The architecture decision (this track's first deliverable) is ratified: Decision 1 = (1b), the editor invokes the extension's bake action directly over the VST-host bridge (NamedCommandLookup/Main_OnCommandEx), no poller/nonce, dissolving the S13 DEGRADED verdict; Decision 2 = (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. Extension presence resolved to cleanly-unavailable, not silently lossy — the affordance refuses up front when the extension is not loaded. Reset-scope edge cases classified against the ratified rule: play mode → RESET to Trigger, start point → RESET, channel mode and preview velocity → SURVIVE. Phase Γ's additions remain NOT this track's — Γ-W3-T2 bake-reset-amendment still amends the reset list for Γ's own new values, unaffected by this landing. Naming and lineage is proposed (KickKick r2Kick r3) but not itself ratified — still open jointly with Ξ-W1-T1's lineage-record question, which Ξ-W1-T1 answered on its own side (OriginRecord::parentSampleId). Nothing was verified in a live REAPER session; Daniel's manual verification is still owed.


Ξ-W3 — The capture-signal popup

Depends on Ξ-W2 for: the bake chain that the popup programs and its preview must not diverge from. The acceptance criterion "preview and bake cannot diverge" requires one render path, which W2 owns — building the preview against a second path is exactly the defect the criterion exists to catch.

One track.

Ξ-W3-T1 — capture-signal-popup

Goal. Let the user program the capture signal — note length, offsets, velocity — and hear it before committing the bake.

Consolidates item 15 (the popup sub-feature).

Surface boundary — owns: core/instrument/ui/curve_popup's sibling — a new pure popup geometry module for the capture-signal sheet (mirror the curve_popup precedent: centered sheet, width/height clamps, title row, Close button rect, outside-sheet dismissal test) — plus the editor's popup paint/input wiring in the deck or chrome band, and the preview trigger's call into W2's render path. Reads Ξ-W1-T2's note-program record; does not re-own it.

Behavior.

  • A popup menu programs the capture signal: note length, start and end offsets — in ms AND in beats — and velocity.
  • A preview trigger button auditions the capture note exactly as currently programmed — the user hears the bake before committing it — and the offline pass renders that same programmed performance.
  • Note length is a musical-division picker spanning 1/64th to 64/1 with dotted and triplet multipliers.
  • Offsets are anchored — start to note-on, end to note-off — and each is readable and editable in both ms and beats, the two views of one stored value.
  • Beat-denominated values resolve against the project tempo under the cursor. The shell reads the tempo; the arithmetic is Ξ-W1-T2's.
  • The programmed velocity is the render velocity — material because the velocity transfer curves modulate amp, pitch, and filter at that velocity.
  • House-consistent: drawn through the shared kit by palette role, geometry pure and CTest-covered, no decorative animation.

Acceptance criteria.

  • The popup exposes: note length as a musical-division picker spanning 1/64th to 64/1 with dotted and triplet multipliers; start and end offsets, each readable and editable in both ms and beats, anchored to note-on and note-off respectively; and velocity.
  • Its preview trigger auditions the capture note exactly as programmed, and the bake renders that same programmed performance — preview and bake cannot diverge. Verify structurally (one render path), not just by ear.
  • Beat-denominated values resolve against the project tempo under the cursor: the same programmed division yields a correspondingly different rendered duration when the tempo at the cursor differs.
  • The programmed signal persists with the instance and round-trips save/reload.
  • The popup's geometry and dismissal test are pure and unit-tested; no hit-test math lands in shell code.

Open questions. Both of Ξ-W1-T2's residuals (negative offsets; the note-length denomination seam) surface here as UI consequences — if T2 answered them, this track implements the answer; if T2 deferred either, this track is where it becomes visible and must be closed.


Phase Γ — The instrument's control surface

Ships: the deck reflowed into two categorical rows with a double-height MASTER bus deck, a PITCH/RATE deck with playback-rate and baseline-pitch controls, a master limiter with dynamic reported latency and a real output meter, one consistent knob interaction/taper law across every variable control over a stage-time range raised 2 s → 10 s, a fix for staged contour traces drawing straight, a re-approached loop/crossfade marker UX under an explicit chrome-row loop enable, the Phase Ξ bake's reset list corrected, and — as the phase's last track — the instrument's first VST3 automatable parameters, reported to the host under a frozen id contract.

Consolidates: none of the seventeen. Phase Γ came from a direct interview with Daniel (2026-08-01); the product reasoning, the measured layout table, the invariant collisions and the fork rulings are in docs/product/instrument-control-surface.md, and the parameter system's is in docs/product/parameter-automation.md §§610. Read §1.2 (the layout table) and §7 (collisions) before dispatching any track here — every number in this phase is derived there, and docs/TODO.md's old deck-rework geometry is superseded.

Fork state — SEVEN ruled, ONE OF THEM LATER REVERSED, NONE OPEN. Indexed at spec §8, folded into the tracks below:

  • Γ-F1kEditorMinHeight stays 680.
  • Γ-F2 — the limiter has lookahead with DYNAMIC reported latency (zero when off, the lookahead when on, reported to host PDC). This inverted the product recommendation; W1-T2's scope grows accordingly — spec §3.1.1.
  • Γ-F3 — RULED, THEN REVERSED THE SAME DAY. First ruled "the ceiling stays 2.0 s in this phase"; then Daniel: "extend the stage lengths to 10s." kEnvTimeMaxSeconds / kGateStageMaxSeconds move 2.0 → 10.0 in Γ-W1-T1, and the docs/TODO.md entry that carried the ambition is discharged rather than deferred. The reversal's cause is Ruling 1 — parameters now ship in-phase, so the ceiling is a one-way door that must be walked through before them, not after. Spec §4.3.1.
  • Γ-F4 — there is an explicit loop enable, and it lives on the chrome row, not in a deck. W2-T2's scope grows accordingly — spec §6.4.
  • Γ-F5 — MASTER's reserved slot is one cell. The 90 px headroom argument behind that is spec §1.6 and governs every future control addition.
  • Γ-F6ship dynamic latency as ruled. The restartComponent(kLatencyChanged) deactivate/reactivate the SDK mandates is accepted: "the limiter will either be on or off on its instance, toggling during playback is not a use case." No constant-latency fallback, no measurement gate. This ruling also corrected the analysis — spec §3.1.1.
  • Γ-F7 — RULED: SIGNAL FLOW. Daniel, 2026-08-01: "signal flow order." The VST3 parameter order — both the frozen id numbering and the getParameterInfo presentation index — is PITCH/RATE → PITCH ENV → FILTER → FILTER ENV → AMP → VELOCITY → VOICE → MASTER, the deck's own sampleDeckGroups rule, with each group's cells in the semantic order the id table freezes. The editor's visual rows after the reflow were the rejected alternative. The reason, because a future reader will ask why the id order does not match the screen: the editor's layout has already moved twice (Θ-W6-T1 grew the floor 840 → 980; Γ-W3-T1 takes it to 1190 and re-rows every group) and within-row order is settled by width fitting, not by meaning — so binding a permanently-frozen id order to a demonstrably mobile layout guarantees the two drift apart, after which the order is neither logical nor matching. Signal flow is the axis that does not move. Full argument and the accepted residual cost: docs/product/parameter-automation.md §6.4; the resulting 44-id table is stated at §6.2.

Ruling 1 (Daniel, 2026-08-01) — VST3 parameter reporting ships in this phase. Verbatim intent: "correct the phase gamma plan to account for complying with the VST3 standard for parameter reporting… by the end of gamma we have the automatable params reported. Make the parameter order logical." docs/product/parameter-automation.md was written as scoping and has been promoted in place: §§15 are the original analysis, §§610 are the specification Γ-W4-T1 is built from. Four things it decides that the scoping pass left open: the blob stays authoritative and parameters are a third surface onto the one model (§6.1); the id space is an independent, hand-assigned, FOREVER-FROZEN table, now stated in full as 44 numbered rows in signal-flow order (§6.2, §6.3); the exposed list is derived from the three-state commit predicate, never hand-maintained (§7); and, under Ruling 3, every parameter's plain unit, range and display precision (§6.7). Today the plugin has zero parameters — ReaSamplerProcessor::initialize (reasampler_processor.cpp:56-73) never populates SingleComponentEffect::parameters, so getParameterCount() returns the SDK default 0.

What the Γ-F6 ruling changed in the analysis, not just in the plan. Dynamic latency reporting is routine for VST3 instruments and REAPER handles it as a matter of course; the SDK's deactivate/reactivate requirement (pluginterfaces/vst/ivsteditcontroller.h:105-108) is the normal contract, not an exotic one. What makes the cycle expensive here is entirely our own doing: ReaSamplerProcessor::setActive(true) calls reloadInstrument() — a bridge read plus a full WAV re-decode (reasampler_processor.cpp:89-97) — where a typical plugin's setActive only allocates and frees buffers, and the deactivate side's freeing of live_/draining_/graveyard (:98-107) is likewise our own design. The cost is therefore ours to reduce if it ever matters, and the reduction is decoupling reload from activation — not abandoning dynamic latency. That improvement is filed as a docs/TODO.md entry with its trigger condition; it is not scheduled in this phase.

Sequencing against Phase Ξ — the ordering claim is RETIRED and replaced by an owned correction. This plan previously asserted that Γ must run before Ξ-W2 and called it "a correctness point, not a preference." Ξ-W2-T1 ran first. That was not a decision anyone took — the track was live before this phase existed (Daniel: "xi was started before I spun you up, we'll have to correct phase xi inside gamma. wasn't a choice."). So:

  1. The bake's reset list is incomplete as shipped, and Γ-W3-T2 amends it. Rate, pitch offset and the limiter flag are all reset under Ξ-W2's own ratified rule (spec §3.4), so no Daniel decision is owed — only the edit, and it must be made against what Ξ-W2-T1 actually shipped rather than against what this plan predicted it would ship.
  2. Ruling 1 adds a second correction of the same shape, and it lands one wave later. Exposing the reset-class values as VST3 parameters means the bake's reset must notify the host, and a host automation lane on a reset-class parameter re-imposes its curve onto already-baked audio. Both are Γ-W4-T1's acceptance criteria — that track creates the condition, so it carries it (docs/product/parameter-automation.md §9).
  3. The payload-ladder half of the old claim needs re-checking, not restating — see the ladder block below, which now states rungs relatively rather than by number.

The organizing constraint. Six surfaces are single-writer and dictate the wave shape: ui/deck_values.cpp and the taper module extracted from it (the taper law and the new ceiling, then the two new controls, then the host normalization — three tracks, three waves), editor_paint_waveform.cpp (the contour trace, then the loop marks), ui/deck_groups.cpp (the row predicate, then the PITCH/RATE descriptor, then the reflow's row consumption — three tracks, three waves), engine/voice.cpp (the Preserve read path, then the rate compounding into it), shell/instrument/reasampler_processor (the limiter chain and latency, then the parameter surface), and the params-payload ladder. Every wave boundary below is one of those collisions, not a preference. Where a wave has more than one track, the tracks are disjoint by surface.

Resequenced 2026-08-01 (Daniel), three changes. The prior four-wave shape put the reflow at W3 and the Preserve stretcher at W4; both moved. Ruling 1 then added a fourth wave — see "The wave shape after Ruling 1" below.

  1. The reflow is split, canvas from arrangement. The window floor and the width budget it is derived from land early (Γ-W1-T4), so every other UI track in the phase is drawn, tested and judged at the final 1190 × 680 window instead of at a size a later wave changes under it. The two-row arrangement stays late (Γ-W3-T1), because it can only be measured once the final PITCH/RATE and MASTER descriptors exist. The seam is stated at Γ-W1-T4.
  2. preserve-time-stretch moved W4 → W1-T5. It is the longest pole in the phase and has zero dependency on any UI work — a pure core/instrument/engine/ module. Scheduling it last was a scheduling error. Consequence: it is no longer Rate's successor but its prerequisite, which retires the interim resample-and-cancel stand-in entirely — see Γ-W2-T1.

Net: four waves become three, and both of the phase's DSP unknowns (the limiter, the stretcher) are exposed in wave 1 rather than one of them landing last.

The wave shape after Ruling 1 — three waves become four. The parameter system cannot be a track inside any existing wave, and the reason is a chain of hard prerequisites, not caution:

  • after W1-T1, because the taper and the 10 s ceiling are the host-facing normalization, and Γ-W1-T1 is also what extracts them into the one module the host will read through;
  • after W1-T2 and W2-T1, because every control that could be a parameter must exist before the list is declared — the list is derived from the control inventory, and an inventory that is still growing produces a list that has to be re-frozen;
  • after W2-T1 specifically, because isLiveDeckParam becoming three-valued is the prerequisite of the classification, not an incidental of it: the exposed set is exactly Live NoteOnLatched;
  • after W3-T1, because MASTER's inventory (the limiter toggle, the GR bubble, the reserved cell) is the last change to what controls exist at all;
  • after W3-T2, so the bake's reset list is already complete when Γ-W4-T1 adds the host-notification obligation over it — one amendment instead of an amendment to an amendment.

The result is a single-track Γ-W4, which is the right shape for it anyway: the storage decision governs every part of the work, exactly as Ξ-W2-T1's crossing decision governs its chain. And it satisfies Daniel's own framing literally"by the end of gamma we have the automatable params reported."

The params-payload ladder — re-checked, and now stated RELATIVELY. The old block named v14 and v15 as absolutes. That is no longer safe to assume, because Ξ ran ahead of its sequencing and this plan is not the record of what Ξ-W2-T1 actually took. On dev today kParamsPayloadVersion is 13 (map/component_state_io.h:154) and Ξ-W2-T1 was specced to take no rung — but the plan's prediction is not evidence. So:

Γ owns the next three rungs above whatever dev carries when Γ-W1-T2 dispatches, and that number is READ, not assumed. In order: the first rung to W1-T2 (the limiter enable flag), the second to W2-T1 (rate + pitch offset), the third RESERVED for W4-T1 — spent only if the storage-architecture verification forces a persisted field, which the specification says it will not (docs/product/parameter-automation.md §6.1, §10). If unspent, that rung falls through to the next phase unclaimed.

On dev as of 2026-08-01 that resolves to v14 / v15 / v16-reserved. If Ξ-W2-T1 landed a bump, every number shifts by one and nothing else about the ownership changes — which is the whole point of stating it relatively.

Every other track in the phase owns no rung: W1-T1 changes no persisted field (the payload stores raw engine doubles, so both the taper and the new ceiling are persistence-neutral), W1-T3, W1-T4 and W1-T5 add no field, W2-T2's loop enable maps onto the already-persisted SampleLoop::hasLoop, W3-T1 is layout only, and W3-T2 changes a reset list, not a format.

The editor's deck is knowingly mis-composed between Γ-W1-T4 and Γ-W3-T1, and that is not a defect report. Raising the floor without the reflow leaves the greedy whole-group wrap packing two ragged left-aligned rows with categorically wrong membership. Γ-W1-T4 states the exact interim layout; do not "fix" it in a track that does not own it.

Phase-wide acceptance criteria (in addition to the ones stated at the top of this file):

  • Bypassed means byte-identical. With the limiter off, the per-sample output path is byte-identical to today's bare ramped multiply — the same discipline that makes live == nullptr byte-identical to the pre-live core and the filter's exact skip at modAmount == 0 hold the at-rest path unchanged.
  • No ComponentState sound change. A project saved before this phase reopens sounding identical: absent rate lifts to 100 %, absent pitch offset to 0 st, absent limiter flag to bypassed. Re-tapering a knob and raising the stage-time ceiling (both Γ-W1-T1) change needle angles only — the payload stores raw engine doubles, so saved values reload bit-identical, and a 3 s stage saved at the old ceiling is simply unreachable-by-hand rather than altered.
  • kVelocityPitchRangeSemitones / kPitchDepthMaxSemis (24.0) does not move. It is load-bearing in the v12 wire format. The new Pitch knob reads it; it does not mint a second ±24 constant. From Γ-W4-T1 it is also a frozen host normalization — one more reason, not a new rule.
  • The taper has exactly ONE home and three consumers, and from Γ-W4-T1 the taper IS the host's toPlain/toNormalized. Γ-W1-T1 extracts it into a pure module; the knob's needle (deck_values), the AHDSR overlay's schematic axis (envelope_overlay + envelope_edit), and the host's normalizedParamToPlain / plainParamToNormalized (Γ-W4-T1) all call the same function. Three functions that agree today is a defect, not an implementation choice — the failure it prevents is a host automation lane that means one value and a needle that draws another. Under Ruling 3 this stops being an analogy: toNormalized is not like the taper, it is the taper (docs/product/parameter-automation.md §6.7.3).
  • ONE formatter per unit category, and the editor and the host are both its callers. The formatter is pure and returns the digits of a plain value in that category's single units string — no embedded unit, no magnitude-switched unit, no width-conditional abbreviation, no caller-side branch. The editor's knob label and getParamStringByValue read the same function. The editor and the host printing different text for the same stored value is a defect class, forbidden structurally rather than caught at review — same discipline, same reason, as the taper criterion above. Consequences (existing formatters stop embedding their unit; cutoff's k abbreviation is retired; the curve dial's ^ is static cell chrome, not value): spec §6.7.2.
  • Every default value has an EXACT normalized preimage under its own taper. Binds Γ-W1-T1 (which designs the taper) and Γ-W4-T1 (which declares ParameterInfo::defaultNormalizedValue). resetDeckParam bypasses the taper; a host's reset-to-default cannot, so exactness in the map itself is the only thing that makes the editor's reset and the host's reset land on the same value. Ruling 3 tightens this twice and adds one non-requirement (§6.7.7): defaultNormalizedValue is computed as toNormalized(default), never written as a normalized literal; the assertion is made on toPlain(defaultNormalizedValue), the pair the host actually calls; and toNormalized(toPlain(n)) == n at arbitrary n is explicitly NOT required — no log map satisfies it in double, and demanding it would over-constrain the taper for nothing.
  • Nothing in this phase may re-map the filter's four normalized controls. Cutoff, Q, morph and drive persist as *Norm doubles in payload v9 — their laws are already wire-frozen, and re-tapering them would re-tune every saved project independently of automation. The snap-unit table names them; that is display, not law. This does NOT conflict with Ruling 3's real-unit requirement, and the two must not be read as a collision: toPlain is a pure read-side mapping that never touches the stored value, so reporting Hz / Q / drive depth means calling filterCutoffHzFromNorm and its peers, not replacing them — which the editor's own labels already do today. The prohibition forbids editing those laws; the requirement is satisfied by calling them. One additive gap: drive has no published inverse and filterNormFromDriveDepth must be added beside the two that exist — the analytic inverse of a frozen law is not a change to it. Spec §6.7.5.
  • Shift-snap is a drag rule; stepCount is a parameter property; they are independent. The editor's snap grid must never be exposed as ParameterInfo::stepCount — that would quantize the parameter itself, permanently and for the host's automation too, freezing the grid into the forever contract and putting continuous cents out of reach from a lane. All 44 exposed parameters ship stepCount = 0, swept and confirmed, and the coincidence is structural: every discrete control is reload or rebuild tier and therefore omitted by the predicate. Spec §6.7.6.
  • From Γ-W4-T1, the parameter-id table is FOREVER-FROZEN, on the same footing as the extension's "STABLE_FOREVER_STRING" command ids, the two VST3 class UIDs, and the params-payload field order. No id is reassigned, reused or re-pointed; no exposed parameter's normalization ever changes; a retired control's id is retired with it. Full wording: docs/product/parameter-automation.md §6.3.
  • The exposed parameter set is DERIVED, never hand-maintained. A control is a parameter if and only if its commit class is Live or NoteOnLatched. There is no second table beside isLiveDeckParam / liveCommitFor, and no list that can drift from it.
  • The window floor is 1190 × 680 and must not exceed 1280 × 720. Γ-W1-T4 sets it, in wave 1; no other track in the phase may move it, and from that point every track is authored and judged at it. A track that pushes the floor past 1280 has failed, not overrun. kEditorMinHeight stays 680 (Γ-F1). The remaining 90 px of width headroom is the budget for the life of this layout — one deck cell is 60 px, so there is room for exactly one more, once. Spec §1.6 states the ledger; read it before adding any control. Chrome-row additions are a separate purse (they are paid for out of the title slot, not the floor) and must not be charged against this one.
  • Reported latency is zero unless the limiter is on. getLatencySamples() returns 0 with the limiter bypassed, in every track and at every point in the phase. Only W1-T2 may introduce a non-zero value, and only under the limiter-on condition.
  • Geometry stays pure. Every new layout, cap, label and hit-test rule lands in a pure CTest-covered module (knob_deck, sample_bands, waveform_view), never in a painter.

Γ-W1 — Foundations

Depends on: nothing in this phase. Five tracks, disjoint by surface — re-verified against this membership rather than carried over from the four-wave shape:

Track Owns
T1 knob-interaction-law a new pure taper module under core/instrument/ui/, ui/deck_values, ui/envelope_overlay + ui/envelope_edit (the AHDSR schematic axis and its drag inverse), ui/param_slider, the three shell/instrument/editor_input_* drag paths, editor_controls.cpp's envClampBounds only, the shared modifier helper in editor_internal.h
T2 master-bus-audio new pure engine/limiter + engine/meter_ballistics, shell/instrument/reasampler_processor + processor_state, map/component_state_io + params_payload (the wave's payload rung)
T3 contour-trace-curves shell/instrument/editor_paint_waveform.cpp's staged trace + a new pure tessellation module
T4 editor-floor-and-row-law ui/sample_bands.h (the floor), ui/knob_deck.h (budget constants + two invalidated header notes), ui/deck_groups (the row predicate only), five test fixtures
T5 preserve-time-stretch engine/pitch_shift + a new pure stretcher module, engine/voice.{h,cpp}'s Preserve read path

Two shared files in the wave, named rather than discovered at merge. src/core/instrument/engine/CMakeLists.txt — T2 declares two new pure libraries and their test targets there, T5 declares one. And, newly, src/core/instrument/ui/CMakeLists.txt — T1 declares the taper module and its test target, T3 declares the tessellation module and its. All four are append-only additions in separate blocks — textual merge adjacency, not semantic contention. Whichever lands second rebases.

Three near-misses that are avoided by construction, and must stay avoided.

(a) T3's tessellation helper lands in a NEW pure module — explicitly NOT ui/envelope_overlay, which T1 now owns, and not in editor_internal.h, which T1 is also editing. The prior wording offered envelope_overlay as an option; Ruling 2 removed it, because T1's schematic-axis work rewrites that module's whole time→x map. This still satisfies the phase's geometry-stays-pure criterion, so it costs nothing.

(b) T1 and T3 are disjoint by file but coupled by data, and the coupling has a stated resolution. T1 owns where an AHDSR's vertices land; T3 owns the stroke between vertices. T3's tessellation is over φ across a segment's pixel span, so the tapered axis changes nothing about the curve it draws — but T3's tests must assert against the returned vertices, not against absolute pixel literals, or they break when T1 lands. Whichever track lands second rebases; expressing T3's assertions relatively makes that rebase free.

(c) T4 touches deck_groups but adds only the new row predicate; it does not touch sampleDeckGroups, which W2-T1 and W3-T1 own in later waves, and it does not touch deck_values, which is T1's.

Two consumption boundaries worth stating, because they look like collisions and are not. T1 consumes engine/master_gain's dB taper for its whole-dB snap and does not edit it; T2 does not touch it either. And T2's payload rung is the wave's only format change — T1's taper and ceiling changes are persistence-neutral by construction (the payload stores raw engine doubles).

Both of the phase's DSP unknowns are in this wave — T2's limiter and T5's stretcher. That is deliberate: they are the two tracks whose gate can fail, and failing in wave 1 is recoverable in a way that failing in the last wave is not.

Γ-W1-T1 — knob-interaction-law

Goal. One consistent, unit-category-driven interaction and taper rule across every variable control, over a stage-time range raised 2 s → 10 s, landed before any new control is added so the new ones are authored into it rather than retro-fitted — and before any parameter is declared, so the law is what the host is handed rather than something the host has to be reconciled with later.

Spec: docs/product/instrument-control-surface.md §4, §4.3.1 (the 10 s ceiling and the overlay-legibility design — new, read it before scoping this track), and docs/product/parameter-automation.md §8 (the one-way-door sweep this track discharges).

Surface boundary — owns: a new pure taper module under core/instrument/ui/ (the ms/semitone/exponent maps, extracted so they have one home), core/instrument/ui/deck_values (the bindings, the snap-unit table, resetDeckParam), core/instrument/ui/envelope_overlay (the ceiling constant and the AHDSR schematic axis) and core/instrument/ui/envelope_edit (its drag inverse), core/instrument/ui/param_slider (the drag law), shell/instrument/editor_input_* (modifier read + re-anchor), shell/instrument/editor_controls.cpp's envClampBounds only (it reads kEnvTimeMaxSeconds), and the modifier-reading helper the three input paths share. Does not own any deck descriptor, any parameter, the waveform painter, or engine/master_gain (consumed, not edited).

Why this track does NOT split, asked and answered. Ruling 2 makes it materially bigger — tapers, modifiers, re-anchor, reset bypass, the ceiling, and the overlay's schematic scale. Two splits were considered and both are serial, not parallel, so neither buys any concurrency: an interaction half (modifiers, snap, re-anchor) needs the domain half's taper and snap-unit table to exist first; and a standalone overlay-axis track needs the taper module and the final ceiling before it can define a stage's slot width. Splitting would therefore cost a wave and gain nothing, while putting the single most identity-critical function in the phase across a wave boundary — the same function the host will normalize against three waves later. The seam that matters is internal and is a deliverable: the taper is extracted into its own pure module, which is what makes "the taper IS the host-facing normalization" structurally true rather than a comment. The ~600-line ceiling is a per-file bar, and the extraction is what keeps every file under it.

Behavior.

  • Shift snaps to whole numbers in the control's displayed unit; Ctrl scales the drag by 0.05; Shift+Ctrl = Shift wins (Ctrl is ignored — with an integer-quantized output a finer drag yields the same sequence, so this is identity, not a compromise).
  • Snap unit by category: ms knobs → whole ms; semitone knobs (incl. Rate, when it arrives) → whole semitones; percent/fraction knobs → whole percent; the 12 curve-exponent inner dials → whole numbers (which puts 1.0, the linear neutral, one snap away); master gain → whole dB; already-integer controls unchanged. Full table in the spec §4.2.
  • Mid-drag modifier transitions re-anchor — on every press and release during an active drag, the current value becomes the anchor value and the current cursor position the anchor position. The value is continuous across the transition; only the rate changes. Without this the grab-anchored absolute drag (kKnobDragRangePixels = 128) jumps by (1 0.05) × the accumulated delta.
  • Millisecond knobs become log-scaled. Exactly 0 s at norm 0 and exactly kEnvTimeMaxSeconds at norm 1, monotone throughout; 10 ms lands within 0.120.20 of travel and 100 ms within 0.420.52.
  • The stage-time ceiling moves 2.0 s → 10.0 s (Daniel, reversing Γ-F3): kGateStageMaxSeconds (envelope_overlay.h:85) and, through it, kEnvTimeMaxSeconds (deck_values.h:22). The two move together or not at alldeck_values.h reads the overlay's constant rather than restating it precisely so they cannot drift (deck_values.h:19-22). The taper's landmarks above are fit against the new ceiling, which is why the ceiling cannot be a follow-up: fitting the taper twice is the only other way to get there.
  • resetDeckParam's bypass becomes MANDATORY rather than merely required-anyway. deck_values.h:42-46 records that exact default recovery depends on the ceiling being a power of two; 2.0 is, 10.0 is not, and the log taper compounds it. Nothing here may be "simplified" back into a norm round-trip under any circumstance.
  • NEW, and the sharpest requirement in the track: every default must have an EXACT normalized preimage under its taper. ParameterInfo::defaultNormalizedValue (Γ-W4-T1) is normalized, so a host's reset-to-default arrives as toPlain(defaultNorm) — and the host has no resetDeckParam bypass to use. The bypass fixes the editor's reset and cannot fix the host's; only exactness in the map itself makes the two land on the same value. This binds the taper's shape, so it belongs here and cannot be handed forward. Master gain's unity (≈ 0.714 norm) is the case where a hair off is audible.
  • The AHDSR overlay's schematic axis becomes the taper — the ceiling's real cost, and it is design work, not a constant change. Each of the four timed stages gets an equal slot and today maps seconds across it linearly (gatePxPerSecond, envelope_overlay.cpp:33-34). At 2 s a 30 ms attack is 1.5 % of its stage's domain; at 10 s it is 0.3 %, under a pixel at the floor width. The fix: a stage's slot width becomes slotPx × taperNorm(seconds) instead of slotPx × seconds / ceiling, so a node's position within its slot is its knob's needle position. Legibility becomes ceiling-independent by construction; the one-model invariant gets stronger rather than strained; and the drawn curve is unaffected, because the taper decides only where a stage's end node lands while φ still runs linearly across the stage's pixel span — so Γ-W1-T3's φ^p trace composes with it rather than fighting it. The AHD policy is untouched: an AHD maps 1:1 onto the waveform's own PCM-aligned time axis and stays linear in seconds. Two alternatives (content-fit auto-scale; a minimum drawn stage width) were considered and rejected — spec §4.3.1 names why, and neither is to be reintroduced as a "simplification."
  • envelope_edit's drag inverse must remain the EXACT inverse of the draw. Both read the same taper module; a node dragged to a pixel and the knob's value at that pixel are one number, not two that agree.
  • The taper is EXTRACTED into its own pure module, with its own <module>_tests target, because it now has three consumers in two different dependency layers: deck_values (which sits above envelope_overlay), envelope_overlay/envelope_edit (which sit below it), and — from Γ-W4-T1 — the host. Leaving it inside deck_values would force an inverted include edge. Do not solve that by copying the map.
  • Semitone knobs become log2/centre-expanded. Symmetric, exactly 0 at centre, exactly ±kPitchDepthMaxSemis at the ends, monotone; ±7 st reached at 5058 % of each half-travel.
  • resetDeckParam bypasses the taper — it writes the default value directly instead of round-tripping through norm → value. This removes the power-of-two dependency the header currently documents rather than working around it; that comment (deck_values.h:42-46) becomes wrong and must be rewritten.
  • Scope is the parameter, not the widget. Deck knobs (outer ring and inner dial), envelope stage nodes and curve knots all honour it — they are surfaces onto one model, and a snap on one but not the others is a divergence. Waveform markers are explicitly excluded: they carry a shipped zero-crossing snap on the same modifier space and their domain is frames.

Acceptance criteria.

  • Every taper change is verified persistence-neutral: a project saved before the change reopens with bit-identical stored values and identical audio; only needle angles move.
  • Holding Shift mid-drag on each unit category lands the documented whole unit; releasing it does not jump the value.
  • Holding and releasing Ctrl mid-drag is continuous — no step at either transition.
  • Double-clicking any knob (outer ring and inner dial independently) lands exactly on its default at every taper, verified against a default-constructed PlaySeconds rather than a round trip.
  • The log/log2 landmark positions above are asserted in the taper module's own tests, and hold at the 10 s ceiling — the fit is against the new ceiling, not the old one.
  • Every default round-trips exactly through norm → value, asserted per unit category against a default-constructed PlaySeconds and against master_gain's unity. This is the criterion Γ-W4-T1 will declare defaultNormalizedValue from; it fails here, not there.
  • A stage time of several seconds is reachable by hand with no loss of resolution below 100 ms, and kEnvTimeMaxSeconds == kGateStageMaxSeconds is asserted, not assumed.
  • A project saved at the 2 s ceiling reloads with identical stored seconds and identical audio — the ceiling change is persistence-neutral for the same reason the taper is.
  • The AHDSR overlay reads legibly at both ends of the new range: a default 3 ms attack is a visible, grabbable node at the floor width, and a 10 s decay still lands its end node at its slot's edge. Assert the node separation, then judge the result by eye in the DAW.
  • The overlay's drag inverse is the exact inverse of its draw at the tapered axis — nodeAtPoint / resolveNodeDrag and buildEnvelopePolyline round-trip.
  • The AHD 1:1 policy is unchanged, asserted: a sustain-less envelope's x-axis stays wall-clock over the waveform.
  • The taper module is pure, CTest-covered, and is the ONLY definition of each map — a grep finds no second copy in deck_values, envelope_overlay, or the shell.
  • The filter's four *Norm controls are untouched by the taper pass — cutoff, Q, morph and drive are already wire-frozen in payload v9; a regression baseline proves their audio is unchanged.
  • One shared modifier-read helper serves all drag surfaces; no second modifier grammar exists.

Open questions.

  • No [Daniel] questions. Fork Γ-F3 is REVERSED: the ceiling moves to 10.0 s, in this track. Daniel's "a horrifically long decay with tight exp" is the case it serves, and the docs/TODO.md entry that carried it is discharged rather than deferred again. The reversal's cause is Ruling 1 — a range endpoint is host-facing normalization, free to move now and permanently expensive after Γ-W4-T1. Both of the prerequisites the deferred entry named are in this track anyway: the log taper (which is what makes a higher ceiling usable at the low end rather than unusable) and the reset bypass (which retires the power-of-two dependency — 2.0 is a power of two, 10.0 is not). The engineer should know the reset bypass is now doing triple duty and must not be "simplified" back into a norm round-trip under any circumstance.
  • [propose at review] the exact shape of the taper, subject to the landmark bounds and the exact-default-preimage requirement. Those two together are tighter than either alone, and the second is easy to satisfy by accident and easy to lose in a refactor — assert it, do not observe it.
  • [propose at review] whether the tapered schematic axis wants a visible tick or gradation cue, now that it is no longer linear in time. The plan's lean is no — the ms labels carry the number and the editor's no-decoration policy stands — but a reader who finds the axis illegible in the DAW should say so rather than silently adding one.

Γ-W1-T2 — master-bus-audio

Goal. The master limiter and the meter's audio and publication halves, plus the plugin's first latency reporting — no editor drawing. Landing the audio ahead of the deck is what lets Γ-W3 draw against real published state instead of a stub.

Spec: docs/product/instrument-control-surface.md §3.1, §3.1.1 (latency — read this first; it was rewritten when Γ-F6 closed, so an older reading of it is wrong), §3.23.3, §3.5, §7.10, §7.11, §8.2.

Surface boundary — owns: a new pure limiter module and a new pure meter-ballistics module under core/instrument/engine/ (each with its own <module>_tests target), shell/instrument/reasampler_processor (the chain, the published block state, and the getLatencySamples / restartComponent(kLatencyChanged) path), and the phase's FIRST params-payload rung (the limiter enable flag). Does not own MASTER's deck geometry or any drawing — that is Γ-W3-T1. Read kParamsPayloadVersion on dev and take the next rung above it rather than assuming the number — Phase Ξ ran ahead of this plan's sequencing, so the plan is not the record of what the ladder currently carries. On dev as of 2026-08-01 that resolves to v14.

Behavior.

  • Chain: voice mixer → master gain (existing ramped multiply) → limiter (bypassable) → output bus, with the meter tapped at the bus output, post-limiter.
  • Limiter: a single toggle, no configurable controls. Baked ceiling 0.3 dBTP. Default off. No makeup gain, ever, of any kind — transparent at rest. Stereo-linked detection (max |L|,|R| drives one gain) so the image is not moved.
  • True-peak detection is sidechain-only — an oversampled detector in the sidechain, never oversampling the signal path. Factor is the engineer's call under the measure gate.
  • Lookahead, with DYNAMIC reported latency (Γ-F2, ruled). getLatencySamples() returns 0 when the limiter is off and the lookahead in samples when it is on; the toggle calls IComponentHandler::restartComponent(kLatencyChanged). None of this exists today — there is no getLatencySamples override, no kLatencyChanged, and no restartComponent call site anywhere in src/; the plugin ships the SDK default of 0. This track introduces the plugin's first latency reporting.
  • The restart is routine; the fencing is against a standing scar, not against the flag. Dynamic latency reporting is ordinary VST3-instrument behaviour and REAPER handles it as a matter of course. The SDK's deactivate/reactivate requirement (pluginterfaces/vst/ivsteditcontroller.h:105-108) is the normal contract. What makes the cycle expensive here is this plugin's own setActive — reactivate calls reloadInstrument(), a bridge read plus a full WAV re-decode (reasampler_processor.cpp:89-97), where a typical plugin only allocates buffers; deactivate frees live_/draining_/graveyard (:98-107) for a documented reason (ghost sustained voices). Γ-F6 is ruled: ship it — the toggle is a patch-design gesture, not a during-playback one. Do not build a constant-reported-latency fallback and do not gate the deliverable on a measurement. The reduction of that self-inflicted cost is filed in docs/TODO.md ("Decouple the instrument reload from VST3 activation") with its trigger condition; it is out of scope here. The four requirements below survive as engineering hygiene against the kIoChanged scar, and all four are acceptance criteria:
    1. Verify the whole call sequence against the vendored Steinberg SDK before writing it, including the ordering rule that the new latency is what getLatencySamples returns after setActive(true) — so the reported value must derive from persisted state, not from a transient the deactivate clears.
    2. Prove the restart does not disturb the output bus arrangement. The output stays one permanently-stereo bus, never renegotiated.
    3. Ship a regression test in the spirit of testDualMonoStereoSampleRendersCentered — a dual-mono capture rendered across a limiter toggle stays centered, L ≡ R.
    4. restartComponent is never called from process(). Main/UI thread only, and coalesced so repeated clicks produce one restart per settled state. This is NOT the change reasampler_processor.cpp:66-68 forbids. That warning is against reintroducing per-mode bus renegotiation (kIoChanged class), which panned a dual-mono capture hard right in the host's pin re-routing; kLatencyChanged is a different flag and the bus is untouched. But the precedent — mid-session restartComponent in this plugin has already shipped one real regression — is exactly why (2) and (3) are non-negotiable.
  • Flipping the toggle during playback: apply immediately, do NOT defer to a transport boundary (product ruling, spec §3.1.1). A deferred restart leaves the plugin misaligned by the lookahead with no visible cue, which is worse than a visible interruption; and the host, not the plugin, schedules the deactivate/reactivate anyway. Daniel has accepted the interruption outright (Γ-F6) — it is not a case to design for. Two things remain in scope, and neither is a mitigation for it:
    • A short (≤ 10 ms) equal-gain crossfade over the engage/disengage. Kept as a quality measure, not a mitigation: a limiter engaging is a gain-path change, and this codebase already ramps every gain-path change (kGainRampSeconds, ValueRamp). It also earns its keep independently of the restart, because we do not control when the host acts on the request — our own transition must be clean in the window before it does.
    • The limiter enable is classified NOT automatable (docs/product/parameter-automation.md §3.8) so nothing can flip it at rate. It is also not the plugin's kIsBypass parameter.
  • Per block the processor publishes, as relaxed atomics: per-channel peak max|x|, a latched clip flag, and the block's maximum gain reduction. No dB conversion, no ballistics, no hold timers on the audio thread — the UI converts and runs ballistics from block peaks and elapsed time. This widens the existing advisory-peak pattern (reasampler_processor.h:109-113), which is not reusable as-is.
  • Meter ballistics (pure, unit-tested): instantaneous rise; fall 20 dB/s; peak-hold latched at the running max, held 1.5 s, then falling at the same rate; scale linear in dB over 60…+6 dBFS; clip latches at block peak ≥ 0 dBFS and is cleared on request.
  • The ComponentState payload rung appends the limiter flag as a strict suffix on the existing discipline; the preceding version's blob is a strict prefix and lifts to bypassed.

Acceptance criteria.

  • With the limiter bypassed the rendered output is byte-identical to the pre-change build, asserted by a regression baseline, not by ear.
  • With the limiter engaged, no output sample exceeds the ceiling on program material that exceeds it by up to +12 dB; with it bypassed and gain driven, the output does exceed 0 dBFS (proving the toggle is doing the work).
  • Nothing is louder at rest with the limiter on. A signal that never reaches the threshold is bit-identical engaged and bypassed.
  • No allocation, no lock, no transcendental on the per-sample path; the measure-and-report gate reports per-voice-block CPU with the limiter engaged at 32 voices.
  • The meter-ballistics module is pure and CTest-covered: rise, 20 dB/s fall, 1.5 s hold, clip latch/clear, and the dB↔pixel map are all asserted without a host.
  • A project saved before this change reopens with the limiter bypassed and sounding identical.
  • getLatencySamples() returns exactly 0 with the limiter off, and the lookahead in samples with it on — asserted against the persisted flag, and correct across a deactivate/reactivate cycle.
  • A dual-mono capture rendered across a limiter toggle stays centered (L ≡ R), and the output bus arrangement after a latency-change restart is identical to before it.
  • The plugin emits no hard step at the toggle — the engage/disengage crossfade is asserted on a rendered signal, not judged by ear.

Open questions.

  • No [Daniel] questions. Fork Γ-F6 is ruled — dynamic latency ships as specced, the deactivate/reactivate is accepted, and there is no fallback design and no measurement gate. Do not reintroduce either; the constant-reported-latency option is closed, not shelved.
  • [verify] temp_cortex/ has already been assessed and rejected (spec §3.5) — do not re-litigate it, and do not transplant from it.
  • [record, not a gate] While the limiter is in REAPER under your hand, note what the restart actually costs — do notes cut, is the re-decode perceptible, does transport hiccup — and record it in this track's review. It is not a gate on shipping and no outcome changes the design; it is the trigger-condition evidence for the docs/TODO.md entry "Decouple the instrument reload from VST3 activation," which is where that cost gets reduced if it ever matters. Do not restructure setActive here: its destructive shape is deliberate and its reasoning (ghost sustained voices on reactivate) is documented at the call site.

Γ-W1-T3 — contour-trace-curves

Goal. Staged envelope segments draw as the curve their exponent defines, so the mid-segment knot stops floating off its own trace.

Spec: docs/product/instrument-control-surface.md §5.

Surface boundary — owns: shell/instrument/editor_paint_waveform.cpp's staged-envelope trace and a new pure tessellation module for it. Does not own the loop/crossfade marks (Γ-W2-T2), envelope_overlay's vertex model, or the drawn-EG (spline) trace.

The helper's home is now constrained, not a choice. ui/envelope_overlay was previously offered as a candidate home for the tessellation helper; Γ-W1-T1 now owns that module (the AHDSR schematic axis, per Ruling 2), so the helper lands in a new pure module under core/instrument/ui/. T1 also owns where an AHDSR's vertices land — this track owns only the stroke between vertices, and tessellates over φ across a segment's pixel span, so the tapered axis changes nothing about the curve drawn. Express this track's assertions against the returned vertices, not against absolute pixel literals, and the rebase onto T1 is free.

Behavior. The defect is verified: editor_paint_waveform.cpp:218 drops knots (if (v.knot) continue;) and joins the remaining vertices with straight strokes, and curveMap is never called in the paint path even though the exponent is in scope at :211. Knot positioning already honours the exponent via curveMidLevel (envelope_overlay.cpp:94-105) — that divergence is the visible symptom. The fix draws each sloped stage through the same curveMap the audio uses, so trace and sound cannot diverge; tessellation approach is the engineer's call.

Acceptance criteria.

  • At every exponent the knot's centre lies on the trace, within 1 px — the reported defect, stated as the gate.
  • At exponent 1.0 the segment is visually identical to today's straight line.
  • No visible faceting at the widest segment the canvas can produce; a fixed low tessellation count is not acceptable at full width.
  • All three envelopes, both play modes, all sloped stages (attack/decay/release) — one paint path, one fix.
  • The established trace grammar is unchanged: one weight, kEnvTracePx = 2.0, through the analytic stroker. Both overlay layout policies (AHDSR right-anchored schematic, AHD 1:1) are honoured unchanged. The spline overlay's own trace is untouched.
  • Audio is unchanged — this is a drawing defect only; a regression baseline proves it.

Γ-W1-T4 — editor-floor-and-row-law

Goal. Commit the canvas — the window floor, the width budget it is derived from, and the row every deck group belongs to — so every other UI track in the phase is drawn, tested and judged at the final window size. The arrangement inside that canvas is Γ-W3-T1's.

Spec: docs/product/instrument-control-surface.md §1.1 (the two categories), §1.2 (the floor arithmetic block), §1.6 (the headroom ledger), §7.1 and §7.4 (the two invalidated knob_deck.h notes).

Surface boundary — owns: core/instrument/ui/sample_bands.h (kEditorMinWidth), core/instrument/ui/knob_deck.h (the declared budget constants and the two invalidated header notes), core/instrument/ui/deck_groups.{h,cpp} (the new row predicate only), and the five test fixtures that read the floor — test_sample_bands.cpp, test_deck_groups.cpp, test_knob_deck.cpp, test_sample_chrome.cpp, test_keyboard_strip.cpp. Does not own layoutDeck / deckRowCount / deckHeight behaviour, the justification law, any descriptor, MASTER's inventory or interior, any painter, or any parameter. It changes no drawing code at all.

Behavior — what it commits.

  • kEditorMinWidth 980 → 1190. kEditorMinHeight stays 680 (Γ-F1).
  • Three declared budget constants in knob_deck.h: the row block both rows will justify inside (1020), the right-anchored spanning deck's reserved width (MASTER 142), and the ceiling (1280). These are declarations of budget, not measurements — nothing computes them from a descriptor, and Γ-W3-T1's job is to prove its content fits inside them.
  • The floor is derived, not asserted as a literal. 1020 + kDeckGroupGap(12) + 142 + 2·kPad(8) = 1190. kEditorMinWidth stays a literal in sample_bands.hdo not add an include edge from sample_bands to knob_deck, which would invert the allocator's deliberate independence from the deck (it takes deckHeight as a parameter for exactly that reason). The identity is asserted in test_deck_groups.cpp, which already includes both headers. This is the Θ-W6-T1 derived-floor precedent, landed once and never rewritten.
  • Row membership becomes a property of the group id: DeckRow { Sound, Contour, Spanning }
    • deckRowFor(DeckGroupId) in deck_groups, an exhaustive switch on the isLiveDeckParam discipline, so a future group is a compile error rather than a silent default. Partition: Sound = PITCH/RATE, FILTER, VELOCITY, VOICE; Contour = PITCH ENV, FILTER ENV, AMP ENVELOPE; Spanning = MASTER. Nothing consumes it until Γ-W3-T1 — that is the seam, and it is why the predicate is safe to land now: membership is a property of the group, width is a property of the descriptor, and only the widths are still moving.
  • Γ adds no new deck group, so no later track amends this predicate.

The seam, stated as what this track can and cannot assert.

Can assert today:

  • The derived floor identity above, and kEditorMinWidth ≤ 1280 with 90 px of headroom.
  • kEditorMinHeight == 680, asserted so no later track drifts Γ-F1's ruling.
  • deckRowFor is total over DeckGroupId and yields exactly the partition above.
  • Row 2's natural width already fits the block, in both play modes: 252 + 312 + 312 = 876 ≤ 1020, leaving both its gutters ≥ kDeckGroupGap. Mode-stable because FILTER ENV's and AMP's reserve slots hold them at 312 in Gate and Trigger alike.
  • MASTER's reserve is not yet spent: deckGroupWidth(MASTER) == 72 ≤ 142.
  • At the floor, deck band 216 and waveform band 358 — the reflow's 112 px arrives here, two waves early (see the interim layout below).

Cannot assert yet, and must not force:

  • Row 1's natural width does not fit the block. Today it is PITCH 150 + FILTER 524 + VELOCITY 192 + VOICE 164 = 1030, against the 1020 block. The 50 px deficit is exactly what the two descriptor changes buy: PITCH → PITCH/RATE +42 (Γ-W2-T1) and FILTER's Band|Notch moving to the caption corner 92 (Γ-W3-T1), netting 980. Record the target and the two contributions as a test comment; assert the fit in Γ-W3-T1, and do not pre-empt either descriptor change to close it early.
  • Gutter distribution, the filter tie-line at x = 636, flush outer edges, MASTER's interior and its meter — all Γ-W3-T1. Every one of them measures a descriptor that does not exist yet.

The interim editor, stated exactly so it is not filed as a defect. At the new floor, availWidth = 1190 2·kPad = 1174, and the unchanged greedy whole-group wrap packs:

row 1  PITCH 150 · PITCH ENV 252 · FILTER 524        =  950 used, 224 px ragged right
row 2  FILTER ENV 312 · AMP 312 · VELOCITY 192 ·
       VOICE 164 · MASTER 72                         = 1100 used,  74 px ragged right

Two rows, not three — so the deck band is already 216 and the waveform already draws at its final 358 px, in both Gate and Trigger. After Γ-W2-T1 lands PITCH/RATE the pack is row 1 = 992, row 2 unchanged; still two rows. The composition is wrong in exactly the way the reflow exists to fix — PITCH ENV sits up with the sound decks, VOICE and MASTER sit down with the envelopes, MASTER is still a single-height 72 px box, and both rows are left-packed with dead space at the right. Worse than today in composition, better in proportion. That is the accepted transitional state for the rest of the phase.

Do not convert the two-row interim into a claim. It is a coincidence of the greedy wrap at exactly this width, not a guarantee — which is precisely why Γ-W3-T1's criterion is "two rows by construction, asserted against the group inventory, not observed as a wrap outcome." testDeckFitsInsideTheEnforcedMinimumWindow currently asserts deckRowCount == 3; relax it to an upper bound (<= 2), which is a real regression canary throughout the interim and is subsumed by Γ-W3-T1's exact claim. An exact == 2 here is acceptable only with a comment naming it as a wrap outcome the reflow replaces.

Acceptance criteria.

  • The floor is 1190 × 680, reached by a derived test over the three budget constants, not by a literal — and the derivation is the one Γ-W3-T1 later reads rather than a second copy.
  • Headroom is exactly 90 px against the 1280 ceiling, asserted.
  • deckRowFor is exhaustive over DeckGroupId; adding a group without classifying it fails to compile.
  • Row 2's natural width and MASTER's unspent reserve are asserted, in both play modes.
  • All five floor-reading test fixtures pass at the new floor — including the chrome row, whose title slot gets more room at 1190, not less.
  • No drawing code changes, no descriptor changes, no parameter changes, no audio change. A regression baseline proves the last of those trivially.
  • The two invalidated knob_deck.h notes (§7.1's fourteen-pixel headroom figure, §7.4's cells-and-floor pairing) are re-derived against the new floor, not deleted — §7.4's restatement is the deck's cell metrics AND its group/row composition both drive kEditorMinWidth; none of the three may move alone.

Open questions. No [Daniel] questions. [propose at review] whether the three budget constants belong in knob_deck.h (the deck owns the row block and the spanning-deck reserve) or in sample_bands.h (the allocator owns the floor they derive). The plan's lean is knob_deck.h with the identity in the test, because it adds no include edge; either is defensible, but the derivation must live in exactly one place.

Γ-W1-T5 — preserve-time-stretch

Goal. A real pitch-preserving time-stretcher for Preserve mode, written from established state-of-the-art literature — landed before the control that drives it, so Rate ships onto a finished engine rather than onto a disposable stand-in.

Spec: docs/product/instrument-control-surface.md §2.5.

Moved from Γ-W4-T1 (Daniel, 2026-08-01). It is the longest pole in the phase and has zero dependency on any UI work. The consequence is the interesting one: it inverts the relationship with Rate. Under the old order the stretcher was Rate's quality upgrade and Γ-W2-T1 shipped an interim resample-and-cancel path to make Rate complete on day one; under this order the stretcher is Rate's prerequisite and the interim path is not built at all. Skipping a stand-in that was only ever going to be deleted is the win; see Γ-W2-T1's named contingency for what happens if this track's gate slips.

Precedent for landing a DSP module ahead of its consumer: Θ-W1-T3 (filter-dsp-port) landed the filter DSP as a standalone pure module a wave before Θ-W2-T1 wired it into the voice path, for the same reason — the unknown is the DSP, not the wiring.

Surface boundary — owns: core/instrument/engine/pitch_shift and whatever new pure module the stretcher needs (each with its own <module>_tests target), plus voice.{h,cpp}'s Preserve read path. Does not own any parameter, any UI, the varispeed path, or the deck. It adds no ComponentState field and takes no rung of the payload ladder.

Behavior and constraints. The algorithm is the engineer's call under a measure-and-report gate — this plan deliberately names none. The constraints:

  • The stretch ratio is an argument, not a parameter. Nothing publishes a non-unity ratio until Γ-W2-T1's Rate knob does. Until then the Preserve read path runs at ratio 1.0 and must be bit-identical to the shipped Preserve read — a stronger and cheaper regression gate than the old plan's A/B-against-an-interim-path, because the baseline is a build that exists.
  • CPU stance (Daniel, verbatim intent): "we should be efficient but accept the cost of high-quality algorithm choices. It's 2026, most people's computers can handle audio with ease. Just don't be wasteful."
  • RT-safe: no allocation, no I/O, no lock in process(); buffers sized at voice allocation or at the off-audio-thread reload, on pitch_shift's existing pre-warm precedent.
  • Per-voice state, holding up at the 32-voice ceiling. The gate is 32 simultaneous Preserve voices at 50 % and 200 %, not one voice at 100 %.
  • No new third-party dependency (pitch_shift's standing property).
  • No dispatch on the per-sample path — concrete, inlineable types; no IStretcher.
  • Onset behaviour is a regression surface. GA2 eliminated Preserve's ~25 ms onset latency by priming the ring with the actual upcoming source. A stretcher that reintroduces an onset delay or a first-frame smear is a regression, not a trade-off.

Acceptance criteria.

  • Ratio 1.0 with no shift is bit-identical to the shipped Preserve read, asserted by a regression baseline — the null case, and the criterion that makes landing this ahead of Rate safe.
  • Preserve speaks on frame 0 — no added onset latency, no first-frame smear, in any ratio/shift combination.
  • No audible metallic or phasey artefacting on sustained tonal material at ±6 st and 75133 % ratio; transient material at 50 % / 200 % is no worse smeared than varispeed playback at the equivalent ratio — the honest "what does preserving pitch cost" reference, and the one that needs no disposable implementation built to serve the comparison.
  • The Gate sustain-loop contract is unchanged: loop the source, shift the output — loop points remain source-frame facts.
  • Measure and report before the algorithm is final: per-voice CPU at 32 voices, added latency (must be zero at the onset), and A/B recordings on three material classes (one-shot, tonal sustain, full-mix bounce). Report to Daniel; the choice is not final until he has heard the A/Bs.

Open questions. [propose, with a measurement step] the algorithm family itself. [verify] that core/instrument/CLAUDE.md's "WDL_Resampler is not a Preserve engine — never wire it as the duration-preserving path" is honoured: under Preserve, Rate legitimately changes duration, so a resampled read is an explicit duration control — but the pitch-preserving mechanism must not be a resampler. No [Daniel] questions.


Γ-W2 — New controls, and the overlay's marks

Depends on Γ-W1 for — four dependencies, two of them new:

  1. T1 ← W1-T1 (taper law). Rate and Pitch must be authored into the finished taper/modifier law, not retro-fitted into it, and the semitone taper must exist before a second semitone knob does.
  2. T1 ← W1-T5 (the stretcher) — NEW, and the reason the interim path is gone. Preserve Rate has no engine without it. Under the prior four-wave order this dependency ran the other way and was paid for with a disposable resample-and-cancel stand-in; the resequencing inverts it. Rate must not ship before its Preserve engine.
  3. T2 ← W1-T3 (the contour trace). Both write editor_paint_waveform.cpp; running them together is a merge fight in one file.
  4. T2 ← W1-T1 and W1-T4, weakly. W1-T1 also edits editor_input_waveform.cpp (the modifier read), which T2 rewrites for marker hit-test routing — serial, so not a conflict, but T2 rebases onto it. And T2's "the enable costs no window width" criterion is now asserted against W1-T4's derived floor test rather than one this track has to write.

T1 additionally inherits engine/voice.{h,cpp} from W1-T5 — a hand-off, not a conflict: W1-T5 defines the Preserve ratio seam, and T1 feeds it. Serial across waves by construction.

Disjointness — re-verified against this wave's membership, not carried over. Both tracks stayed in W2 and nothing entered or left it, so the prior finding is re-checked and stands. T1 owns the parameter model, the engine and the deck descriptors; T2 owns the waveform band's marks and their pure geometry and the chrome row's loop enable. The two are disjoint at the module level with one named exception: shell/instrument/editor_session.cpp. T1 may touch it for the third commit tier's routing; T2 owns pickedMarkers and applyMarkers there and nothing else. The partition is by function and the two do not overlap — textual merge adjacency, not semantic contention — but it is a shared file in a phase whose wave boundaries are otherwise single-writer surfaces, so it is stated rather than discovered at merge. Whichever track lands second rebases onto the first. No new in-wave adjacency was created by the resequencing: T2 touches neither deck_values nor deck_groups nor voice.

One cross-wave hand-off, new with Ruling 2 and NOT a contention. Rate's taper — linear in semitones over ±12, the stated exception to the centre-expansion law — belongs in the taper module Γ-W1-T1 extracts, since that module is the one home of every map. T1 therefore appends a law to a module a previous wave created. Serial across waves by construction, the same shape as its engine/voice.{h,cpp} hand-off from W1-T5. What would be wrong is a second taper defined inside deck_values' binding — one home, appended to, not forked.

The format ladder stays clean. The loop enable maps onto the existing SampleLoop::hasLoop, which is already persisted and whose start/end are already written unconditionally — no new field, no version bump — so T1 keeps sole ownership of the phase's second payload rung exactly as specced (v15 on dev as of 2026-08-01; read the ladder rather than assuming the number).

Γ-W2-T1 — pitch-rate-deck

Goal. PITCH becomes PITCH/RATE: three knobs (Key Trk | Rate | Pitch) under the existing Varisp|Presrv toggle, with both new controls wired through the engine.

Spec: docs/product/instrument-control-surface.md §2.

Surface boundary — owns: core/instrument/engine/play_params.h + core/instrument/map/play_seconds.h (the two new fields), core/instrument/map/component_state_io + params_payload (the phase's SECOND payload rung — v15 on dev as of 2026-08-01; read the ladder, do not assume the number), core/instrument/engine/voice.{h,cpp} (the compounding and the note-on latch), core/instrument/ui/deck_groups (the PITCH/RATE descriptor and the three-state live predicate), core/instrument/ui/deck_values (the two new bindings). Does not own the deck's row layout — that is Γ-W3-T1 — nor the time-stretcher itself (Γ-W1-T5, already landed by the time this track runs).

Behavior.

  • Rate: 50 %200 %, default 100 % at true knob centre, exponential taper — 50 % = 12 st, 200 % = +12 st, musically symmetric. This is linear in semitones over ±12 and is the stated exception to W1-T1's centre-expansion law (which applies to semitone knobs whose throw exceeds ±12).
  • Pitch: a baseline pitch offset, ±24 semitones, centred, on W1-T1's centre-expanded semitone taper. Reads kPitchDepthMaxSemis; does not mint a second constant.
  • Varispeed: keytrack ratio × rate ratio × pitch-offset ratio compound into a single read-increment multiply; the rate offset applies to the varispeed pitch. Composes with the pitch envelope's existing per-frame ratio_ multiply — no new per-sample stage.
  • Preserve: rate is an absolute value driving duration only; keytrack and pitch offset drive the pitch shifter. Rate drives the stretch ratio Γ-W1-T5's stretcher already consumes — there is no interim path. The stretcher is this track's prerequisite, not its successor; the resample-and-cancel stand-in the prior plan carried is retired unbuilt (see Open questions for the contingency). core/instrument/CLAUDE.md's "never wire WDL_Resampler as the duration-preserving path" is honoured by construction.
  • Rate is latched at note-on, delivered by a third commit class: published into the live block like any live parameter, read only by snapLive, never by applyLive. isLiveDeckParam/liveCommitFor widens from two states to three (Live / NoteOnLatched / Reload) in that one predicate — not a second table, and not the reload tier (a swept knob must never trigger a WAV re-decode). Record the reason in the header: loop resolution and contour mapping are note-on folds, so live rate means re-folding a resolved loop and re-mapping a contour mid-note.
  • Pitch is live — under Varispeed one more factor in a multiply the pitch envelope already performs; under Preserve an addend to a shift the pitch envelope already modulates.
  • Loop points scale with rate; contours scale with rate. Neither rewrites stored values: the loop is source-frame facts traversed at the new increment (Varispeed) or the new read rate (Preserve), and a contour is a function of normalized position. Staged envelope stage times do NOT scale — 30 ms is 30 ms at any rate. That asymmetry is deliberate: a contour is of the sample, a staged envelope is of the performance.
  • Deck descriptor: three cells; captionWidth 70, hard ceiling 80 (above that the caption row overtakes the 180 px knob row and the group exceeds 192). If the text will not fit at 80, narrow the Varisp|Presrv segments 48 → 44 (ceiling becomes 88) — do not widen the group.
  • The payload rung appends both fields as a strict suffix; the preceding version's blob lifts to rate 100 % / pitch 0 st, bit-identical playback.
  • Both new DeckParams are classified in the three-state predicate, and that classification is what puts them in the VST3 parameter list three waves later — Rate NoteOnLatched, Pitch Live. Γ-W4-T1 derives the exposed set from this predicate rather than from a list of its own, so a mis-classification here is a mis-declared parameter there.

Acceptance criteria.

  • Rate at 50 % plays an octave down and half speed under Varispeed; at 200 %, an octave up and double speed. Under Preserve the same settings change duration only — pitch is unchanged within the stretcher's tolerance. Preserve Rate is a finished feature the day this lands, because Γ-W1-T5 already shipped its engine; a degraded or inert Preserve Rate is a failed track, not an acceptable interim.
  • Rate at exactly 100 % and Pitch at exactly 0 st render bit-identical to the pre-change build, in both engines.
  • Shift-drag on Rate lands on whole semitones (so an octave and a fifth are reachable by hand); Shift-drag on Pitch lands on whole semitones; Ctrl gives cents on both.
  • A Rate change while a note sounds does not alter that note; the next note-on takes it. It does not trigger a reload or an engine rebuild — assert the tier, not just the sound.
  • A Pitch change does move a sounding note, in both engines.
  • With a loop set, changing Rate changes the loop's audible period without moving either waveform marker.
  • The PITCH/RATE group measures exactly 192 px; adding the two DeckParams produces a compile error in isLiveDeckParam's exhaustive switch until they are classified.
  • A project saved at the preceding payload version reopens at rate 100 % / pitch 0 st and sounds identical.

Open questions.

  • None [Daniel].
  • [propose at review] Rate's clamp behaviour at the range extremes as it meets the stretcher's own ratio bounds — one clamp, resolved where the two meet, not two that can disagree.
  • Named contingency, not a plan item, and not to be taken silently. If Γ-W1-T5's measure-and-report gate has not passed when this track is ready to dispatch, the pre-agreed fallback is the resample-and-cancel composition spec §2.5 records — a resampled read with the resulting pitch change cancelled in the existing SOLA shifter — shipped as an interim Preserve path with the stretcher as its later quality upgrade, i.e. a return to the prior four-wave order. Escalate to Daniel rather than taking it: it revives a disposable implementation and re-opens the WDL_Resampler guardrail conversation, and the whole point of the resequencing was to avoid building it.

Γ-W2-T2 — loop-crossfade-ux

Goal. Give the loop an explicit enable, make the loop and crossfade marks legible, and paint the crossfade where it is actually heard.

Spec: docs/product/instrument-control-surface.md §6 — read §6.1 (the diagnosis), §6.4 (the enable) and §6.5 (trade-offs) in full before starting. This is the phase's one genuinely designed surface; the sections are the brief.

Surface boundary — owns: shell/instrument/editor_paint_waveform.cpp's marker/loop draw, shell/instrument/editor_input_waveform.cpp's marker hit-test routing, core/instrument/ui/waveform_view (cap rects, label boxes, the label-suppression rule — all pure, all CTest-covered), and — new, from the Γ-F4 rulingcore/instrument/ui/sample_chrome (the enable's rect in the toolbar control run), shell/instrument/editor_paint_chrome + editor_input_chrome (its draw and hit-test), and shell/instrument/editor_session.cpp's pickedMarkers / applyMarkers only (the retention rule — see the wave header for the shared-file partition). Does not own loop_span, the crossfade model, any parameter, or any ComponentState version. This track changes drawing, hit-testing and one editor-state retention rule — no format change.

Behavior.

  • An explicit loop enable on the CHROME ROW (Γ-F4, ruled). A two-segment Loop Off|On toggle joins the toolbar row's right-anchored control run, immediately left of the Mono|Stereo toggle, with Browse still rightmost. Loop is a waveform-overlay concept and has no deck — a deck cell was never the right home. Because the run is right-anchored and the title slot absorbs it, this costs zero window width and none of the 90 px headroom; if the title will not hold its text at the 1190 floor, the enable's segments narrow — the floor does not move.
  • The enable IS SampleLoop::hasLoop. No new field, no version bump. The field already exists (play_params.h:210), is already what resolveLoop refuses on (loop_span.cpp:12), and is already persisted in the payload's loopOverride block — where start/end are written unconditionally whatever hasLoop says (params_payload.cpp:31-36), so the wire can already carry "off, with a span remembered." What changes is the field's provenance: today it is derived from the marker gesture, and after this track it is user-owned, with the gestures as shortcuts onto it.
  • Collapse-to-off survives as a shortcut, not as a second state machine. hasLoop is the single authority; four gestures reach it:
    Gesture Enable Span Crossfade
    Enable → On on retained retained
    Enable → Off off retained retained
    Collapse the span onto itself off destroyed, re-parked at defaultLoopBounds zeroed
    Drag either loop mark while off on takes the drag retained, re-clamped
  • Two consequent behaviour changes, each with its reason. (a) pickedMarkers' re-park (editor_session.cpp:221-226) currently triggers on !hasLoop; it must become conditional on the span being invalid (collapsed / inverted / out of range) rather than on the enable being off — a toggle whose off→on does not restore what was there is a delete button, not a toggle. (b) applyMarkers' crossfade zeroing (:240-243) moves from "the enable is off" to "the span was destroyed." The original reasoning is preserved, not overruled: it zeroes so a stale length cannot silently re-apply against a span that no longer exists; with the span retained, its clamp bound is retained too and there is nothing stale.
  • The "drag me" affordance splits into two off-states. Off with no span ever set — pair parked at defaultLoopBounds, Disabled, caption DRAG TO SET LOOP. Off with a span retained — pair Disabled at its own positions, caption LOOP OFF (there is nothing to "set"). In both, dragging a mark turns the enable on — the shipped drag-to-create gesture survives and now teaches the enable by demonstration.
  • In Trigger the enable draws Disabled and inert, and does NOT clear hasLoop — Disabled-not-hidden, the same grammar as the marks, with its state restored on the return to Gate. This transitively covers the drawn-EG case via enforceGateUnavailableWhileDrawn (play_params.h:198-205), which forces Trigger whenever an envelope is drawn — one predicate, not a second rule. Disabled-but-grabbable (the off marks) vs. Disabled-and-inert (Trigger) is deliberate: the user's own off is reversible by the very gesture on offer; Trigger's refusal comes from the engine and no drag can talk it out of it.
  • One mark grammar: line + shaped cap + label. The cap IS the grip. Four marks: START (accent/primary, solid right-pointing triangle cap, solid line — the only primary-ink mark, because it is the only one always in effect); LOOP (accent/secondary, L-cap opening right); END (accent/secondary, L-cap opening left); XFADE (accent/secondary reduced alpha, ramp cap, dashed line — a soft boundary). This replaces the bare 10 px orphan tab that today marks the crossfade with no line of its own.
  • Labels in Font::Micro/TextDim, drawn beneath the trace and handles in z-order. A mark's label re-draws on top on hover or drag of that mark. A label is suppressed if its box would overlap one already placed; placement order is grabbed/hovered first, then START, LOOP, END, XFADE. Occlusion by an envelope node is accepted and named — the cap shape carries the identity permanently, the label is for learning.
  • The crossfade moves to [loopEnd crossfade, loopEnd) — where it is audible. The handle moves to the loop-end side; drag direction is unchanged (left lengthens), so the muscle memory survives.
  • The crossfade region draws as a top-and-bottom edge wedge, NEVER as a second fill. A triangular band at the overlay's top and bottom edges growing from zero at loopEnd crossfade to ~10 px at loopEnd. This is a hard constraint: the region is now inside the loop span, where a translucent fill would stack on the 0.20 loop fill, and the envelope trace crossing that fill is a known, accepted under-floor pair at 2.25:1 (editor_paint_waveform.cpp:28-34), whose own note says the FILL is what changes if it is ever resolved. The loop fill's peak alpha must stay exactly 0.20.
  • The ingredient draws as a ghost. [loopStart crossfade, loopStart) draws the mirror wedge at half alpha, no handle — a hairline dashed outline at rest, filling in on hover or drag of the crossfade handle. This makes the crossfade ≤ min(start, loopLength) clamp self-explanatory: the fade stops growing exactly when the ghost's left edge reaches START or LOOP, so the user sees the reason instead of hitting an invisible wall.
  • Trigger mode: the loop pair and the crossfade mark draw Disabled and are not grabbable, with a dim LOOP — GATE ONLY caption — Disabled rather than hidden, matching the editor's existing Gate-segment grammar, and because hiding a set loop on a mode flip destroys information the user put there. START stays fully live.

Acceptance criteria.

  • The four marks are distinguishable by ink and cap shape with the labels suppressed, and named when they are not.
  • The shaded crossfade region sits over the frames where the fade is audible — verify against a rendered loop, not by reading the code.
  • Every mark is grabbable by its cap; grabbing a mark shows its label.
  • The crossfade at its clamp shows the ghost's left edge coincident with the bounding mark.
  • The loop fill's peak alpha is unchanged at 0.20 and the accepted 2.25:1 trace pair is neither improved nor worsened.
  • In Trigger, no loop mark accepts a grab, the chrome enable is Disabled and inert, and the reason is on screen. Returning to Gate restores the enable's prior state.
  • Turning the enable off and on again restores the loop exactly — same span, same crossfade, no re-park. Collapsing the span instead turns it off, re-parks at defaultLoopBounds and zeroes the crossfade. Both paths asserted.
  • Dragging a loop mark while the enable is off turns it on, in both off-states.
  • The enable costs no window width: kEditorMinWidth is unchanged by this track, asserted by the same derived test that guards the floor.
  • No ComponentState version moves; no new persisted field; resolveLoop is untouched; audio is unchanged. The enable round-trips save/reload through the existing loopOverride block, in both states, with the span retained across an off.
  • All cap/label/suppression geometry is pure and unit-tested; no hit-test math in the painter. The enable's rect lands in sample_chrome alongside the rest of the control run.

Open questions.

  • [propose at review, then verify by hand] The claim-arbitration inputs change: markerHandleRect today gives a tab to the crossfade only, and resolveWaveformClaim breaks ties by smallest nominal target area. Giving every mark a cap-grip changes the candidate set and every nominal area in it. The arbitration must be re-derived, and docs/TODO.md's open entry "Pre-existing staged-envelope-node shadow at zero-attack" must be re-evaluated against the new cap geometry and its outcome recorded — resolved or worsened, either is acceptable, silence is not.
  • No [Daniel] questions. Fork Γ-F4 is ruled — there is an explicit enable and it is on the chrome row, in this track. The prior framing ("an enable needs a cell, so it is a Γ-W3 layout decision") was wrong and is retired: loop has no deck, so it never needed one.
  • [propose at review] every site that currently infers hasLoop — two in editor_input_waveform (:255, :258), two in editor_session (:222, :236) — is now writing to a user-visible control rather than to an internal flag. Re-read each in that light; "it still compiles" is not a disposition.
  • Named escalation, not a fallback to take silently: if the top strip reads crowded in the DAW, the pre-designed answer is the marker rail (spec §6.2, Direction 2) — a larger build that would also dissolve the arbitration problem structurally. Escalate; do not improvise a half-rail.

Γ-W3 — The reflow, and the bake correction

Depends on Γ-W2 for: the PITCH/RATE descriptor (W2-T1) — the reflow measures the real three-cell group, and laying it out against a forecast of that group means re-measuring afterward. This is the whole reason the arrangement is late, and it is why the canvas was split out of it into W1-T4. T2 depends on the same wave for a different reason: rate and pitch offset must exist before the bake's reset list can name them.

Depends on Γ-W1 for: W1-T2's published meter/GR/clip state, which MASTER's deck draws (drawing against a stub would mean building the meter twice), and W1-T4's floor, budget constants and row predicate, which T1 consumes rather than re-derives. T2 depends on W1-T2 for the limiter enable flag, the third of the three values it must add.

Depends on Phase Ξ for T2 — the phase's only EXTERNAL gate. Ξ-W2-T1 (resample-bake-chain) must have landed on dev before T2 dispatches. T2 amends what that track shipped; it cannot amend a branch.

Two tracks, disjoint by surface — but T2's disjointness is CONDITIONAL and must be confirmed, not assumed. T1 owns ui/knob_deck, ui/deck_groups (row-predicate consumption, FILTER's caption move, MASTER's inventory) and shell/instrument/editor_paint_deck. T2 owns the bake's reset step wherever Ξ-W2-T1 put it. T2's first act is to read what actually shipped and confirm its reset surface touches none of T1's three modules. If the shipped reset enumerates controls through deck_groups or deck_values, the two are not disjoint and T2 serializes behind T1 inside the wave — a named contingency, taken openly, not discovered at merge. That risk is real precisely because this plan cannot predict the shipped shape; predicting it is what put the phase in this position.

Why T1 is one track. The row law, the group inventory and the double-height deck are one geometry decision spread over knob_deck, deck_groups and the deck painter. Splitting it would put two tracks in the same pure modules. The window floor is no longer part of it — W1-T4 set it two waves ago, and this track must not move it.

Neither track takes a payload rung. T1 is layout only; T2 changes a reset list, not a format.

Γ-W3-T1 — deck-reflow

Goal. Two categorical rows plus a double-height MASTER bus deck, inside a 1280 × 720 ceiling, returning 112 px to the waveform.

Spec: docs/product/instrument-control-surface.md §1 (the whole section, incl. the §1.2 measured table and §1.6, the headroom ledger) and §3.23.3 (what MASTER draws). §7 lists the invariants this track invalidates or widens — read it before touching knob_deck.h.

Surface boundary — owns: core/instrument/ui/knob_deck (the row law, the double-height group, the justification — consuming W1-T4's budget constants, not restating them), core/instrument/ui/deck_groups (consumption of W1-T4's row predicate, FILTER's Band|Notch caption move, MASTER's inventory), and shell/instrument/editor_paint_deck (the MASTER meter/limiter/bubble draw). Does not own kEditorMinWidth or any budget constant — those are W1-T4's and are read, never moved — nor any parameter, the limiter DSP, or the waveform band.

Behavior.

  • Row 1 (sound), one row, non-negotiable: PITCH/RATE 192 · FILTER 432 · VELOCITY 192 · VOICE 164 = 980 natural.
  • Row 2 (contour): PITCH ENV 252 · FILTER ENV 312 · AMP ENVELOPE 312 = 876 natural.
  • MASTER is double-height (216 px) and right-anchored, outside both rows, 142 px wide.
  • FILTER's Band|Notch moves from its row-toggle position to the caption corner, taking the group 524 → 432 (92 px). It occupies FILTER's currently-unused captionToggle2 slot — no new geometry is required.
  • VOICE keeps its Retrig|Legato row toggle. Moving it to the caption makes VOICE wider (226, not narrower), because its caption row is the binding side. Verified; do not "fix" it.
  • Justification law, applied to BOTH rows: space-between within the row block; slack divided equally among the row's (n1) gutters, integer residue to the leftmost; no gutter narrower than kDeckGroupGap (12). Decks are never stretched. MASTER is not part of either row's justification.
  • Row block = 1020 px at the floor, giving row 1 gutters 12/14/14 and row 2 gutters 72/72, at which width FILTER's right edge and FILTER ENV's right edge both land on x = 636. That tie-line, row 2's equal gutters, and row 1's minimum gutter being exactly kDeckGroupGap all hold at 1020 and only at 1020 — this is why the floor is 1190 and not 1186. Above the floor the tie-line drifts and that is accepted (spec §1.3).
  • The floor is already 1190 × 680 and the bands are already 216 / 358 — Γ-W1-T4 landed all four in wave 1, and the greedy wrap happened to reach two rows at that width. This track changes none of those numbers; it makes them true by construction instead of by coincidence. Row 1's natural width fits the block only after this track's Band|Notch move: 1030 today, +42 from W2-T1's PITCH/RATE, 92 here, = 980. That is this track's fit assertion and W1-T4 deliberately left it open.
  • The 90 px of remaining headroom is the budget for the life of this layout, and one deck cell is 60 px. This is why MASTER's reserved slot is ONE cell (Γ-F5, ruled): two would spend 60 of the 90 up front on a control nobody has named, leaving 30 — which would freeze row 1 forever, since any later row-1 addition needs 60. Widening MASTER later costs the same 60 it would cost now, and by then the trade is against a real control instead of a guess. State this ledger where a future reader will hit it — spec §1.6 is its home, and a reader proposing a new knob needs to see it before they propose.
  • MASTER's interior (spec §1.4, exact to the pixel): caption row with the limiter toggle and a round 12 px warn GR bubble in the far corner (non-interactive — the same slot the envelope decks' radio uses; round so it reads as a lamp, not a control); gain knob in the upper-left cell at box-relative y = 26 and a reserved empty slot at y = 138 — i.e. the two cells land on row 1's and row 2's knob baselines exactly, which is what stitches the spanning deck to both rows; meter column 62 px wide × 186 px tall on the right.
  • Three rules not to generalise wrongly: MASTER's left column uses fixed cell slots at the two baselines, NOT the horizontal run-division law (that law would stretch one knob over 186 px); the reserved slot draws nothing (blank reads as breathing room, a dashed placeholder reads as unfinished); the meter is one rect spanning both baselines, not two per-row meters.
  • The meter draws W1-T2's published state, with the ballistics run on the UI timer. Bar count follows the same LaneSplit decision waveformSurface already folds (channel mode ∧ source channel count) — one wide bar when the waveform draws one lane, two skinnier bars when it draws two. Not a second rule: a mono source in stereo mode is dual-mono, and two identical bars would be a lie.
  • Meter appearance: bar in accent/primary; peak-hold tick 2 px in text/primary; clip cap in warn, latched, click-to-clear; scale linear in dB over 60…+6 with ticks every 6 dB and numerals at 0/12/24/36/48/60, the 0 dB tick heavier. No green/yellow/red segmentationwarn stays reserved for clip states.

Acceptance criteria.

  • At the floor width the deck lays out in exactly two rows plus the spanning MASTER, by construction — asserted against the group inventory, not observed as a wrap outcome.
  • Every group's width matches the §1.2 table exactly, in both Gate and Trigger (row 2's natural width is mode-stable at 876 because the reserve slots hold FILTER ENV and AMP at 312 in both modes — assert it).
  • Row 1 and row 2 are flush left and flush right; at the floor width the filter tie-line is exact (both edges at x = 636) and row 2's two gutters are equal.
  • Row 1's natural width is 980 and fits the 1020 block — the fit Γ-W1-T4 could not yet assert, closed here by the Band|Notch move.
  • kEditorMinWidth is still 1190 and the floor is still ≤ 1280 × 720 — unchanged by this track, verified against Γ-W1-T4's derived test rather than a second copy of it.
  • The waveform band is 358 px at the floor, and the deck band is 216 — unchanged from the interim, now reached by construction: deckRowCount at and above the floor is 2 because the row predicate says so, not because a wrap landed there. Assert against the group inventory.
  • MASTER's gain knob shares a knob baseline with FILTER's knobs; its reserved slot shares one with AMP ENVELOPE's.
  • The meter reads correctly in mono and stereo, the peak-hold tick holds 1.5 s, the clip cap latches and clears, and the GR bubble lights only while the limiter reduces gain.
  • With the limiter engaged the clip cap never latches on material the limiter is catching; if it does, that is a defect report against W1-T2, not a user error.
  • knob_deck's and sample_bands' tests are updated to the new law, and the invalidated notes in knob_deck.h (the fourteen-pixel headroom figure; the cells-and-floor pairing) are re-derived, not deleted — spec §7.1, §7.4.

Open questions.

  • [propose at review] Whether the greedy whole-group wrap survives at all as a sub-floor degrade, or is replaced outright by explicit row assignment. What is not optional: at and above the floor width the layout is the specified arrangement, reached by construction. DeckLayout::rowCount/::height change meaning either way (spec §7.3).
  • No [Daniel] questions. Forks Γ-F5 (one cell) and Γ-F1 (680 stays) are both ruled; they are stated in Behavior above, not carried here as options.
  • [verify] deck_groups.cpp's kEnvModeSegW = 23 ceiling rises to 47 once PITCH ENV is on row 2 (AMP binds at 55). No change is required; the comment stating the old ceiling stops being true and must be corrected (spec §7.2).

Γ-W3-T2 — bake-reset-amendment

Goal. Complete the resample bake's reset list against the control surface that now exists — the correction Phase Γ owes Phase Ξ because Ξ-W2-T1 shipped ahead of the sequencing this plan asserted.

Consolidates: nothing from the seventeen. It is a correction obligation, not a feature (see "Flagged for awareness" item 2).

Spec: docs/product/instrument-control-surface.md §3.4, and Ξ-W2-T1's own "Reset scope" block above — which is the ratified rule this track applies, not a rule it may reinterpret.

Surface boundary — owns: the bake's parameter-reset step, wherever Ξ-W2-T1 landed it, and its tests. Does not own the bake chain, the crossing architecture, the replace-vs-add decision, the capture path, any deck module, any painter, any parameter, or any ComponentState version. It changes what a shipped list contains — nothing else.

Behavior.

  • Three values join the reset list, all classified against Ξ-W2's own ratified rule ("reset what the bake baked in"), all reset, none of them a new Daniel decision: rate, pitch offset, and limiter enabled. The limiter's reasoning is worth carrying rather than re-deriving: master gain is already on the reset list, so the bake includes the master stage, so the limiter's effect is in the audio.
  • Verified against what shipped, not against what was predicted. This plan named three values before either the bake or the controls existed. Read Ξ-W2-T1's landed reset list first and reconcile: if it already anticipated any of the three, say so and drop it; if it classified something differently from docs/product/instrument-control-surface.md §3.4, the landed code is the fact and this plan is the prediction — escalate the difference, do not silently overwrite either.
  • Re-run Ξ-W2-T1's own "genuinely new parameter" check over everything Phase Γ added, not just the three named. Γ also ships the loop enable (W2-T2) and raises the stage-time ceiling (W1-T1). Classify each against the rule: the loop enable is a loop fact whose effect is in the rendered audio (reset, with the loop points it travels with); the ceiling is not a parameter at all. State each disposition; silence is not one.
  • Root note still survives. The bake's most load-bearing exception is untouched by this track — capturing at root is what makes root survivable, and resetting it would detune every subsequent iteration.

Acceptance criteria.

  • After a bake, rate reads 100 %, pitch offset 0 st, and the limiter reads bypassed — and the root note, key-tracking and the VOICE group are still untouched.
  • The bake stays audible and faithful with the new controls dialled in: dial rate, pitch offset and the limiter, bake, and the neutral instrument playing the programmed note sounds as the dialled one did — the criterion Ξ-W2-T1 already carries, now actually exercised over Γ's controls.
  • A reconciliation note in the track's review stating, per value, whether the landed code already covered it, and recording any difference between what shipped and what §3.4 predicted.
  • No format change, no new field, no version bump, no change to the crossing architecture or the replace-vs-add decision. A regression baseline proves the bake's audio is otherwise unchanged.

Open questions.

  • No [Daniel] questions. The rule is ratified and §3.4's classification is derived from it.
  • [verify, FIRST] the disjointness contingency in the wave header: read the shipped reset step and confirm it touches none of Γ-W3-T1's modules. If it does, serialize behind T1 and say so.
  • Explicitly NOT this track's: the two consequences automation adds to the bake — the reset having to notify the host, and a host lane re-imposing its curve onto baked audio. Both are Γ-W4-T1's, because that track creates them. Doing this correction once, before automation, and letting Γ-W4-T1 add its own obligation on top is deliberate: the alternative is an amendment to an amendment.

Γ-W4 — VST3 parameters

Depends on every earlier wave, and each dependency is a hard prerequisite rather than a courtesy:

  1. ← W1-T1. The taper and the 10 s ceiling are the host-facing normalization, and W1-T1 is also what extracts them into the one pure module the host reads through. Declaring parameters against a taper that is still moving is the one-way door this whole phase is ordered around.
  2. ← W1-T2 and W2-T1. Every control that could be a parameter must exist before the list is declared. The list is derived from the control inventory; an inventory still growing produces a list that has to be re-frozen, and it cannot be.
  3. ← W2-T1 specifically. isLiveDeckParam becoming three-valued is the prerequisite of the classification, not an incidental: the exposed set is exactly Live NoteOnLatched.
  4. ← W3-T1. MASTER's inventory (limiter toggle, GR bubble, reserved cell) is the last change to what controls exist at all.
  5. ← W3-T2. The bake's reset list must already be complete, so this track adds the host-notification obligation once rather than amending an amendment.

One track. The storage decision governs every part of the work — the projection rule, the migration path, what getParamNormalized returns, and what the bake's reset must do — exactly as Ξ-W2-T1's crossing decision governs its chain. Every candidate split (a pure model/classification half and a host-wiring half) is serial, so it buys no concurrency and puts the decision on one side of a boundary and its consequences on the other.

Γ-W4-T1 — vst3-parameter-set

Goal. The instrument reports its automatable parameters to the host, under a frozen id contract and a logical order — which also hands it REAPER's whole per-parameter modulation block (LFO, envelope follower, MIDI link, parameter linking) for free.

Consolidates: nothing from the seventeen. Ruling 1 (Daniel, 2026-08-01): "correct the phase gamma plan to account for complying with the VST3 standard for parameter reporting… by the end of gamma we have the automatable params reported. Make the parameter order logical."

Spec: docs/product/parameter-automation.md§§610 are the specification; §§15 are the analysis behind it. Read §6.1 (storage), §6.3 (the freeze), §7 (the classification) and §8 (the one-way-door sweep) before scoping. Today the plugin has zero parameters: ReaSamplerProcessor::initialize (reasampler_processor.cpp:56-73) never populates SingleComponentEffect::parameters, so getParameterCount() returns the SDK default 0. This track introduces the whole surface.

Surface boundary — owns: a new pure parameter-identity module (the frozen id table, the DeckParamParamID mapping, the derived exposed set, the unit assignment — with its own <module>_tests target), shell/instrument/reasampler_processor + processor_state (the IEditController parameter surface and the IParameterChanges read), shell/instrument/editor_controls.cpp and the editor's drag-commit sites (the beginEdit/performEdit/endEdit bracketing), and the bake's reset step for the notification path only. Does not own the taper (W1-T1's module, consumed), any control's value semantics, any deck geometry, or the bake's reset membership (W3-T2's).

Behavior.

  • The blob stays authoritative; a parameter is a THIRD SURFACE onto the one model — a peer of the deck knob and the overlay node, not a second copy of the value. docs/product/parameter-automation.md §6.1 states the load, host→plugin, plugin→host and save rules, and the two verified findings that closed the fork: this plugin is a SingleComponentEffect, where the SDK itself collapses IComponent::setState and IEditController::setState (vstsinglecomponenteffect.h:41-47), so there is one state and §3.3's drift hazard describes a split-component design we do not use; and the blob is a cross-artifact contract the extension's instrument_drop writes, which parameters-as-truth would silently make partial.
  • ParamID is an independent, hand-assigned, FOREVER-FROZEN table — blocks of 100 per deck group in signal-flow order (Γ-F7), steps of 10 within a block, a curve dial at its outer knob's id + 1, blocks starting at 1000. The full 44-id assignment is stated at §6.2 and is to be transcribed, not re-derived. §6.2 also for why hand-assignment beats derivation and why the within-block order is seeded ONCE rather than tracked against cellIds; §6.3 for the freeze invariant, which is to be stated in the table's header with the same force as the command-id strings, the class UIDs and the payload field order.
  • The exposed set is DERIVED from isLiveDeckParam / liveCommitFor, never hand-maintained — a control is a parameter iff its class is Live or NoteOnLatched. 44 parameters at the end of Γ-W3, enumerated by group in §7.1.
  • Everything else is OMITTED from the list entirely, not exposed-and-flagged: the reload and rebuild tiers, all structural state, and the limiter enable (§3.8, settled). §7.2 states why omission beats kIsReadOnly, and names the limitation plainly — the user cannot automate filter on/off, play mode, the pitch engine, Staged↔Spline or polyphony, and the unlock is to give the control a live path first.
  • Every exposed parameter reports REAL UNITS to the host (Ruling 3). Each declares a plain range, a units string, and a display precision; the complete eight-category table covering all 44 — ranges, units, precision, and which taper each category carries — is docs/product/parameter-automation.md §6.7.1, and it is a specification, not a suggestion. VST3's wire format stays normalized (it cannot be otherwise); the requirement is met through the plain-value layer the SDK provides, whose direct precedent in the vendored tree is public.sdk/samples/vst/common/logscale.h:221-229 overriding toPlain/toNormalized for a log law — the exact shape our log ms and log2 semitone knobs need.
  • normalizedParamToPlain / plainParamToNormalized / getParamStringByValue / getParamValueByString route through W1-T1's taper module and the ONE formatter per unit category. Three functions that agree today is a defect; the host's normalization, the needle angle and the overlay node must be the same function. toNormalized IS the taper — §6.7.3 — which is what makes the phase's one-way-door ordering structurally true rather than a warning someone has to remember.
  • stepCount = 0 on all 44, and the editor's shift-snap is never exposed as stepCount. Snapped drag and parameter continuity are independent axes; stepCount quantizes the parameter permanently, including for the host's automation, and freezes into the forever contract. The sweep is done and clean (§6.7.6) — every discrete control is reload or rebuild tier and therefore already omitted, so continuity is structural rather than lucky.
  • IParameterChanges is observed at BLOCK boundaries, stated in the header — the last point in a block wins. Sample-accurate application would put a per-sample "did anything change" question on the per-voice-per-sample path, which the phase-wide guardrail forbids.
  • A host parameter change takes the control's existing commit tier and no other. Nothing on the automation path may reach reloadInstrument or rebuildVoiceEngine — which §7.2's omissions guarantee structurally rather than by care.
  • IUnitInfo: one unit per deck group, mirroring the group inventory rather than the editor's rows. Order is signal flow — Γ-F7, RULED (§6.4). Presentation index order is ascending id, so identity and presentation agree by construction.
  • The filter's four report plain units WITHOUT being re-tapered. toPlain is read-side only; reporting Hz / Q / drive depth means calling filterCutoffHzFromNorm, filterQFromNorm and filterDriveDepthFromNorm — the filter module's own frozen laws, which deckValueLabel already calls today — not restating them. The one additive piece: filterNormFromDriveDepth does not exist and must be added in filter_params, beside the two inverses that do; the analytic inverse of a frozen law is not a change to it. §6.7.5.
  • No kIsBypass on anything. The plugin is an instrument and exposes no bypass parameter; the limiter is a safety device, not a bypass, and binding it there would hand the host a control that restarts the component.
  • The bake's reset gains a notification obligation (§9): every internal writer of a value that is an exposed parameter must go through the one beginEdit/performEdit/endEdit path, and the bake's reset is the codebase's first non-gesture writer. Enumerating those sites is part of this track, not a follow-up.
  • Two adjacent SDK surfaces are assessed, with dispositions, so they are not re-surveyed: IMidiMapping is in scope and nearly free (a CC → ParamID map, one function); IParameterFunctionName is not implemented (its vocabulary is compressor/panner semantics that name nothing here); IAutomationState is not implemented (it reports the host's automation mode for the whole plug-in, not per parameter, so it cannot answer the one question §9 would have wanted it for).

Acceptance criteria.

  • The host lists exactly the derived set, in the ruled order, with no parameter the predicate does not classify Live or NoteOnLatched — asserted against the predicate, not against a literal count.
  • Every id in the table is asserted unique, in its group's block, and on its step — and a test fails if any id changes value, which is what makes the freeze mechanical rather than cultural. The asserted values are §6.2's table verbatim, including the signal-flow block sequence; a test that recomputes the ids from cellIds would defeat the freeze it exists to hold.
  • toPlain(info.defaultNormalizedValue) compares EXACTLY equal to the default, per parameter, against a default-constructed PlaySeconds (and against master_gain's unity), so a host's reset-to-default and the editor's double-click land on the same value. defaultNormalizedValue is computed as toNormalized(default), not written as a literal — a grep finds no normalized default constant. If the exactness fails, it is a W1-T1 defect surfacing here, not a defect of this track. Round-trip exactness at arbitrary values is NOT asserted — it is not required (§6.7.7) and asserting it would over-constrain the taper.
  • getParamStringByValue prints what the editor's knob label prints, digit for digit, at the same stored value, across every unit category — asserted by calling the same formatter from both sides in one test, not by comparing two independently produced strings. A grep finds exactly one formatter per unit category and no snprintf of a parameter value outside it.
  • Every exposed parameter's units and plain range match §6.7.1, asserted per parameter; stepCount is asserted zero on all 44.
  • A host automation lane moving a Live parameter moves a sounding note; a lane moving a NoteOnLatched parameter takes effect on the next note and does NOT trigger a reload or an engine rebuild — assert the tier, not just the sound.
  • No automation path reaches reloadInstrument or rebuildVoiceEngine.
  • A project saved before this change opens with every parameter reading the blob's value and sounds identical; a project saved by this build opens in an older binary with its sound intact; and a project with automation drawn, saved and reopened, replays against the same plain values.
  • process() takes no new indirection and no new per-sample work — the parameter read is a block-boundary act, on the existing live-publish path.
  • The bake's reset notifies the host, verified by the host's displayed value following it rather than snapping back on next touch.
  • The double-processing limitation is documented, not discovered — a bake whose reset-class parameter carries a host lane is a named boundary of the bake's fidelity claim (§9), stated in the product doc and in this track's review.
  • The lane-linearity consequence is stated in the header, not left to be found — under a tapered parameter a straight line drawn in a host automation lane is not linear in the plain unit (exponential in ms, linear in octaves on cutoff, linear in dB on master gain). This is standard and desirable, it follows directly from Ruling 3 plus the taper, and §6.7.4 gives it per category. Writing it down is the acceptance criterion; changing the taper to avoid it is not an option.
  • The filter's four are proven untouched: a regression baseline shows their audio unchanged, and their persisted *Norm values are byte-identical across a save/reload that passes through the parameter surface. Reporting Hz/Q/depth changed display only.

Open questions.

  • No [Daniel] questions. Γ-F7 is RULED — signal flow (2026-08-01, "signal flow order."), and Ruling 3 (real units) arrived specified rather than forked. There is no unanswered [Daniel]-class question in this track or anywhere in this plan.
  • [verify, FIRST] that REAPER calls setState (not setComponentState) on a single-component plug-in, and the ordering of setState against the first IParameterChanges block after a project load. §6.1 is built on the SDK's own name-collapse; verify it in the DAW before wiring, and do not build on the paragraph alone.
  • [verify] whether REAPER renders ParameterInfo::units beside the string getParamStringByValue returns, or shows the string alone. We ship the SDK's own convention — digits in the string, unit carried separately, which is what RangeParameter::toString and the Parameter constructor's signature both express. If REAPER shows no unit at all, the fallback is to append the unit inside the one formatter: a one-line change in one place, touching neither the frozen id table nor the editor, because display strings are explicitly not frozen (§6.7.1). Do not discover this after shipping.
  • [propose at review] promoting key-track and Trigger length from Reload to NoteOnLatched (§7.4). Both are excluded from the live set for the note-on-latch reason in the predicate's own words, so the promotion aligns routing with documented semantics — and it is what makes them automatable at all. If either promotion is refused, that control simply drops out of the parameter list. The list follows the predicate; the predicate is never bent to fill the list. Consequence for the frozen table: a refusal drops ids 1000 and 1260 (key-track) or 1450 (Trigger length) and the count falls below 44. Those slots are then simply never issued — not retired, since nothing shipped under them — and remain available to the same control if it is promoted later. No other id moves; that is what the block-and-step scheme buys.
  • [propose at review] whether to ship a default IMidiMapping CC table here or leave MIDI control to REAPER's host-side learn. Either is defensible; skipping it silently is not.
  • [propose at review] whether this track spends the reserved payload rung. §6.1 says nothing new is persisted and therefore it should not; if the setState verification says otherwise, it takes the reserved rung and says so.
  • Closed, do not reopen: Rate lifted from latched to live (§3.5 records the cost); the limiter enable made automatable (§3.8 — its one reopening condition is the docs/TODO.md reload/activation decoupling, and the answer is to do that first, not to re-litigate the classification).

Phase Ψ — The extension trust pass: exact bounds, disjoint solo surfaces, reachable actions, honest drops, real names, true mono

Ships: capture ranges that mean what was asked — a time selection or razor area over a longer item captures the selection, both scopes; per-mode solo surfaces that cache, clear, and restore across the Design/Arrange switch, with the switch itself refused while the transport runs; the Media-Explorer import action registered into the Media Explorer action section so it can live on that toolbar; a drag-out gesture law that resolves its target from what is actually under the cursor, continuously and reversibly, with no silent no-op release anywhere; captures labeled after their source track instead of the literal "item"/"track", surfaced on the panel card; and lossless mono collapse for new captures whose channels are bit-identical.

Consolidates: none of the seventeen. Phase Ψ came from a direct list of seven defects and refinements (Daniel, 2026-08-01). There is no backing product doc — the design content lives inline in the tracks below, and the seven are recorded here as the phase's provenance, cited throughout as Ψ.1–Ψ.7:

Ψ.1 — item and track captures should be named (labeled) after their source track name, plus a discriminator (date, etc.); currently they aren't named anything useful. Ψ.2 — Design vs. Arrange modes: any SOLO state in one mode is cached and removed when switching to another mode, disjoining the solo surfaces. Ψ.3 — the Design/Arrange active-mode toggle is gated if playback is running; only allow the switch when the project is not playing. Ψ.4 — the action that moves a Media Explorer item to a new ReaSampler on the selected track is not in the Media Explorer action category, so it cannot be added to the Media Explorer toolbar; fix this. Ψ.5 — drag-and-drop targets are inexact: sometimes dropping into the arrange doesn't work, sometimes dropping into the FX area doesn't work; dragging between banks is fine. Ψ.6 — capture into mono: if the left and right channels of a new capture are bit-identical, collapse to mono — one channel of data, mono arrange items, ReaSamplers load in mono mode. Ψ.7 — capture item / capture track with a small time selection on a large item captures the entire item, not the selection/razor; make capture regions consistent and correct.

Where the seven land:

Ψ-item Track Worktree slug
Ψ.7 Ψ-W1-T1 ppsi-w1-t1-capture-range-exactness
Ψ.2 + Ψ.3 Ψ-W1-T2 ppsi-w1-t2-mode-switch-discipline
Ψ.4 Ψ-W1-T3 ppsi-w1-t3-media-explorer-section
Ψ.5 Ψ-W1-T4 ppsi-w1-t4-drop-target-resolution
Ψ.1 Ψ-W2-T1 ppsi-w2-t1-capture-naming
Ψ.6 Ψ-W2-T2 ppsi-w2-t2-mono-collapse

Ψ.2 and Ψ.3 share one track deliberately: they share one chokepoint — applyMode, the sole mode mutator (shell/view/view.cpp:380-469) — and one discriminator (targetModeId != model.activeModeId(), the test that distinguishes a real switch from a reapply). Splitting them is two tracks fighting over the same function.

Concurrency with Γ and Ξ. Phase Ψ is extension-side. Γ and Ξ-W3 live in core/instrument/ + shell/instrument/; the surfaces are disjoint with ONE named exception — Ψ-W2-T2 touches shell/instrument/processor_reload.cpp for a stale comment and an index/file consistency check, and that touch is bounded to the minimum in its surface boundary precisely because Γ is live in that directory.

Three invariant amendments are DELIVERABLES of this phase, not asides. Each is scheduled in — and an acceptance criterion of — its owning track. This spec schedules them; the implementing track performs them:

  1. The never-touch-solo rule (Ψ-W1-T2): src/shell/view/CLAUDE.md:14-17, src/core/view/CLAUDE.md:10, and docs/product/design-view.md:160-165 + :588-592. Ψ.2 requires writing I_SOLO; the amended form is stated in the track. A track that lands solo writes without the amendment reads as an invariant breach in review.
  2. The action-registration contract (Ψ-W1-T3): root CLAUDE.md §"REAPER extension contract" documents only the main-section 4-step pattern; the second, non-main mechanism (custom_action + hookcommand2 + -custom_action mirror) must be added beside it.
  3. The channel-count-preserved rule (Ψ-W2-T2): root CLAUDE.md:208 — "channel count preserved (no silent stereo fold)" — is contradicted in text (not in spirit) by a lossless bit-identical collapse, and was already untrue in the other direction (a mono source renders at RENDER_CHANNELS=2 today). The amended form is stated in the track.

Performance posture. Every Ψ surface is cold — per-capture, per-click, per-mode-switch, per-mouse-move. None of the named hot paths (peaks envelope compute, audition, realtime-capture tick, instrument process()) is touched. Two disciplines carry anyway: the realtime tick's single-pointer-test idle fast path is untouched by Ψ-W1-T1's render work, and Ψ-W1-T4 keeps the inside-client drag path free of SDK hit-tests, exactly as today (panel_drag.cpp:273-274 — "costs nothing on the common internal-drag path").


Ψ-W1 — Exact bounds, disciplined switches, reachable actions, resolved drops

Depends on: nothing in this phase. Four tracks, disjoint by surface:

Track Owns
T1 capture-range-exactness core/capture/render_settings, shell/capture/capture.cpp's render-configuration block, shell/capture/scope_resolve (source-mode selection only), tests/test_render_settings.cppplus, as landed: the new pure core/capture/render_window + core/capture/track_topology, the new shells shell/capture/render_selection + shell/capture/render_isolation, and renderOffline's guard block in shell/capture/capture_orchestrator.cpp (the one seam a fresh capture and a recipe replay both cross, so the refusal and the transient guards had to live there rather than in scope_resolve)
T2 mode-switch-discipline core/view/view_mode_model (solo cache), shell/view/view.cpp (applyMode seams + WANT block), shell/actions/design_view_actions.cpp (refusal feedback), shell/panel/panel_input.cpp footer mode-segment block only (:300-309), the mode segment's disabled state in core/ui/footer_bar + shell/panel/panel_render.cpp
T3 media-explorer-section shell/actions/ingest.cpp (register/dispatch/unregister), the registration block in src/app/main.cpp (the hookcommand2 hook + unload mirror), the root-CLAUDE.md contract amendment
T4 drop-target-resolution core/ui/drag_out, core/wire/instrument_drop, shell/panel/panel_drag.cpp, shell/actions/instrument_drop_win.cpp, shell/actions/drag_out_win.cpp (hand-off timing), tests/test_drag_out.cpp

Why these four are parallel. T1 is capture core/shell; T2 is view core/shell plus one fenced block of panel_input.cpp; T3 is action registration; T4 is the drag chain. No two tracks own the same function anywhere.

Two shared-file adjacencies, named rather than discovered at merge. (a) shell/panel/panel_input.cpp: T2 owns the footer mode-segment block (:300-309) only; T4 may touch the drag-arm block (:382-402) only. Separate blocks — textual adjacency, not semantic contention; whichever lands second rebases. (b) src/app/main.cpp is T3's exclusively. T4 must not touch main.cpp — its whole redesign lives in the drag chain and registers nothing. T2 also does not touch it: the playback gate lives inside applyMode conditioned on the real-switch discriminator, so main.cpp:173's project-load reapply passes through unchanged.

Ψ-W1-T1 — capture-range-exactness

Goal. A capture over a time selection or razor area on a source item substantially longer than the selection produces exactly the requested range — both scopes, no whole-item widening. (Ψ.7)

What is already correct, so the fix does not wander. Range resolution is correct end to end: scope_resolve.cpp:100-112 (resolveRange) → razor union (render_settings.cpp:135-170) or GetSet_LoopTimeRange (scope_resolve.cpp:35-40), passed verbatim (capture_orchestrator.cpp:221-222), landed as RENDER_BOUNDSFLAG=0 + exact RENDER_STARTPOS/RENDER_ENDPOS (capture.cpp:320-322). There is no item-bounds fallback in RunCapture. The widening decision point is the source-mode bit: item scope maps to kRenderSelItems (&32) | kRenderSingleFile (render_settings.cpp:82-86), and the repo's own comments treat &32 as item-extent-driven (capture_batch.cpp:64-66, :98-99 — the entire reason batch transiently selects one item per render). The working inference — unverified without a DAW — is that REAPER's "selected media items" render source overrides the custom time bounds. Track scope uses &128 (selected tracks via master), a normal time-bounded render, and no code path was found that widens it.

Behavior.

  • The track opens with a DAW repro matrix, before any code change [verify]: item scope × {time selection, razor} and track scope × {time selection, razor}, over a source item substantially longer than the selection, tail mode None. This confirms the &32-overrides-bounds inference, and disambiguates Ψ.7's "item/track both" claim — the candidates are: the reporter saw only the item scope; or a non-None panel tail mode was active (capture_orchestrator.cpp:217; Auto adds an 8 s window, render_settings.cpp:28-37). If track scope reproduces with tail None, the analysis above is wrong and the track says so before proceeding.
  • The fix architecture is a design call at implementation review [propose], with the two candidates named now:
    • (a) Re-source the ranged item capture. When item scope carries an explicit range, render time-bounded (e.g. selected-track source &128 over the item's own track, with the item-scope FX-bypass plan unchanged — it already neutralizes the track's own track-FX chain and everything above). Semantic edge to resolve: another item on the same track overlapping the range would now be audible in the capture, where &32 excluded it.
    • (b) Render-then-trim. Keep &32 (only the selected item's audio, REAPER's own semantics) and trim the rendered file to the requested range afterward with the pure wav_codec tools, sample-exactly (offset = requested start rendered start at the file's sample rate). Precedent: trimAutoTailInPlace (capture_realtime_finalize.cpp:55-125). Cost: renders more than needed; requires knowing the rendered file's start time exactly. Whichever candidate lands, the choice is judged against the acceptance criteria below, not against convenience.
  • Ripple surfaces if the item-scope source mode changes, enumerated so none is discovered late: capture_batch.cpp:98-99's select-one mechanism, item-scope FX fingerprinting reading CountSelectedMediaItems (scope_resolve.cpp:199-207), and core/model/provenance recipes storing sourceMode as an int (scope_resolve.cpp:186) — a recorded recipe must replay to the same audio.
  • Batch semantics are deliberately different and stay so: RunBatchCaptureItems is one sample per item at item extent (capture_batch.cpp:177-179) — that is its meaning, not this defect. Stated so nobody "fixes" it.

Acceptance criteria.

  • The bounds equality, stated as a number: the captured file's frame count equals the requested range's duration at the project sample rate — exactly, no rounding — for BOTH scopes, with both a time selection and a razor area, over a source item substantially longer than the selection, tail None. [verify — DAW]
  • The null test holds for a ranged item capture: re-inserted at the range start, it nulls against the source over the range. [verify — DAW]
  • Bit-identical repeats hold for the ranged capture.
  • Full-item captures (no time selection/razor, or bounds equal to the item) are byte-identical to today's output.
  • Recapture-from-source of a ranged capture reproduces it (the provenance recipe stays truthful under the chosen fix).
  • tests/test_render_settings.cpp pins the chosen mapping (today :44-47 asserts only that the &32 bit is chosen — never its bounds interaction); any new pure trim/window arithmetic lands in core/capture with unit tests.
  • DAW-verification obligation: Daniel observes the four-cell matrix above, plus one razor-union case (two disjoint razor areas — the union rule at render_settings.cpp:135-170 is bounds-driven and must not regress).
  • Root CLAUDE.md:208's "Exact bounds" invariant needs no amendment — this track makes the code honor it; the invariant was always the spec.

Open questions. [verify] the override inference and the track-scope repro (the matrix above). [propose] fix candidate (a) vs (b), including (a)'s overlapping-item semantic edge and (b)'s rendered-start-time derivation.

Ψ-W1-T2 — mode-switch-discipline

Goal. Switching the active mode caches and clears the outgoing mode's solo state and restores the incoming mode's — disjoint solo surfaces per mode — and the switch itself is refused, visibly, while the transport is playing or recording. (Ψ.2 + Ψ.3)

The invariant amendment comes first, because without it this track is a breach. The never-touch-solo rule is stated three times: src/shell/view/CLAUDE.md:14-17 ("Never touches master or B_MUTE/I_SOLO… User mute/solo survives every toggle untouched"), src/core/view/CLAUDE.md:10, and docs/product/design-view.md:160-165 (framed as the analog of capture's non-destructive invariant) + :588-592. The amended form: the tool never loses the user's solo state — solo is cached per mode on a real switch and restored verbatim on return, the snapshot sense of non-destructive, exactly as the park/restore snapshots already treat visibility and FX state. B_MUTE stays untouched absolutely; the master track stays untouched absolutely (and survives for free — handleByGuid is built from GetTrack's index space, which excludes master, view.cpp:90-91). All three files are amended by this track.

Surface boundary — owns: core/view/view_mode_model (the solo cache: storage, serialize/deserialize, reconcile participation — mirroring the existing snapshots_ map, view_mode_model.h:284-358), shell/view/view.cpp (the applyMode seams and its REAPERAPI_WANT block, :21-41), shell/actions/design_view_actions.cpp (refusal feedback on the action path), shell/panel/panel_input.cpp's footer mode-segment block ONLY (:300-309), the segment's disabled state in core/ui/footer_bar (pure predicate, transport bool passed IN from the shell) and its paint in shell/panel/panel_render.cpp (:110-125 region), the three invariant-amendment files, tests/test_view_mode_model.cpp. Must not touch: panel_drag.cpp (T4's), src/app/main.cpp (the gate's discriminator makes the project-load reapply pass through unchanged), B_MUTE, master, and the park/restore planner's existing semantics.

Behavior.

  • The discriminator is the hinge for both halves. applyMode is also the reapply path — called with targetModeId == activeModeId() from reapplyActiveMode (design_view_actions.cpp:106-108, reached from tag/untag/show-both at :187,197,206) and from project load (main.cpp:173). A real switch is targetModeId != model.activeModeId(). Only a real switch caches/clears/restores solo, and only a real switch is playback-gated — reapply during playback (tagging, project load) keeps working, and there is no cache/clear/restore flicker on reapply.
  • Solo cache semantics. On a real switch: read I_SOLO for every track in the live enumeration (handleByGuid, keyed by GUID — all non-master tracks, not just managed leaves: a mode's solo surface is the whole project as seen in that mode); store the non-zero values into the model keyed by the OUTGOING mode id (model.activeModeId() is still the outgoing mode at the capture seam); write I_SOLO = 0 on every track that had it set; after setActiveMode (view.cpp:455), restore the INCOMING mode's cached entries verbatim and consume them (clear-on-restore, mirroring storeSnapshot/clearSnapshot). Values are cached and restored verbatim as the raw I_SOLO int — never collapsed to a boolean (solo-in-place and safe-solo variants survive the round trip).
  • Seams in applyMode: capture after handleByGuid is populated (:386) and before Undo_BeginBlock2 (:399); the clear and restore writes both ride the existing single undo block (clear at its head, restore after setActiveMode :455 and before TrackList_AdjustWindows :460) — one mode toggle stays one Ctrl-Z.
  • Storage is pure, shell touches only the API pair. The cache lives in ViewModeModel beside snapshots_ with the same deserialize(serialize(x)) == x contract (view_mode_model.h:347-350); only the GetMediaTrackInfo_Value/SetMediaTrackInfo_Value pair lives in view.cpp, exactly as snapshotTrack (:121-134) does. core/ includes no REAPER headers.
  • Reconcile participation — decided: the solo cache prunes on dead GUIDs, like snapshots and unlike membership (view.cpp:389-395). The hazard it removes: a stale entry restoring onto a reused GUID. A pruned entry is simply lost solo state for a track that no longer exists — correct.
  • Persistence rides the one blob. ViewModeModel::serialize()SetProjExtState(proj, "reasampler", "view_state") (ext_state_io.cpp:156-158, key ext_keys.h:31). parseModel skips unknown keys (view_mode_model.cpp:603), so the new key is backward-safe: an older build reading newer state drops the solo cache silently and nothing else breaks. Stated, accepted.
  • The playback gate. Inside applyMode, when the discriminator says real switch and GetPlayStateEx(proj) & (1|4) (bit 1 playing, bit 4 recording — the precedent is capture_realtime_shell.cpp:284, project-scoped *Ex variants deliberately, comment :192), refuse before touching anything: return false, no partial apply (the same fail-closed shape as the mode-exists guard at :381). Add REAPERAPI_WANT_GetPlayStateEx to view.cpp's WANT block.
  • The refusal is visible, not a silent no-op. The footer [Arrange|Design] segment renders a disabled state while the transport runs, following the one existing disabled precedent end to end: pure predicate (mode_enable-style, transport bool passed IN so core/ui stays REAPER-free) → layout/paint state → no-op click. The action path's refusal (doToggleMode/doActivateMode) reads applyMode's false and skips persist/invalidate.
  • The panel's direct-call divergence is closed in this track — decided. The footer segment click calls applyMode directly (panel_input.cpp:300-309, passing nullptr project), skipping the persistViewState() + bankPanelInvalidate() the action path does (design_view_actions.cpp:165-180) — a pre-existing defect: a panel-initiated switch does not persist. The segment click now routes through Main_OnCommand of the activate actions, exactly as the bottom-bar tag buttons already do (panel_input.cpp:74-75). One path, one gate, one persist.

Acceptance criteria.

  • The disjoint-surface matrix, DAW-observed: solo two tracks in Arrange; switch to Design → no track is soloed; solo a third track in Design; switch back → exactly the two Arrange solos are restored (raw I_SOLO values verbatim, including solo-in-place) and the Design solo is gone; switch forward again → the Design solo is restored.
  • Reapply paths (tag/untag/show-both, project load) neither clear nor flash solo state — before or after this track, during playback or stopped.
  • With the transport playing or recording: the switch is refused on EVERY path (action, panel segment), the segment visibly renders disabled, and project state is untouched by the refused attempt. Stopped → the switch works. Recording gates identically to playing.
  • A panel-initiated switch now persists (the divergence closure): switch via the footer segment, save, reload → the project reopens in the switched mode.
  • Solo cache round-trips save/reload: save mid-disjunction, reload → the inactive mode's cached solos restore on the next switch.
  • One mode toggle remains one Ctrl-Z; B_MUTE is never written; master is never touched.
  • The three invariant-amendment files land amended, in this track.
  • Pure model changes covered in tests/test_view_mode_model.cpp (store/consume, serialize round-trip, reconcile pruning); the enable predicate is pure and tested.
  • DAW-verification obligation: Daniel runs the solo matrix, the playback-gated refusal (playing AND recording), and the panel-persist case.

Open questions. [verify] I_SOLO is settable via SetMediaTrackInfo_Value and its value domain — against vendor/reaper-sdk/sdk/reaper_plugin_functions.h, per root CLAUDE.md's API-verification rule (settability is inference today). [verify] adding REAPERAPI_WANT_GetPlayStateEx to view.cpp alone compiles (main.cpp:15 does not define REAPERAPI_MINIMAL, so it should — inference, one compile answers it). [propose] the repaint trigger for the disabled segment (the panel must notice transport transitions; lean: poll play state in the panel's existing timer tick and invalidate on change). [propose] restore-onto-parked-track edge: a track soloed in mode B, then re-tagged so it is parked when B next activates, would on verbatim restore solo a silent track and mute the mix — lean: restore skips tracks parked in the incoming mode and drops those entries, with the alternative (retain until the track re-enters) named and rejected as zombie state.

Ψ-W1-T3 — media-explorer-section

Goal. The Media-Explorer import action appears in the Media Explorer action section, so it can be bound and placed on the Media Explorer toolbar. (Ψ.4)

Why it lands in Main today (SDK-verified): the action registers via "gaccel" (ingest.cpp:457-468), and gaccel_register_t registers into the main keyboard section only — the struct has no section field (vendor/reaper-sdk/sdk/reaper_plugin.h:1106-1117). The supported mechanism (SDK-verified): custom_action_register_t (reaper_plugin.h:1090-1103) — {uniqueSectionId, idStr, name, extra}, with Media Explorer = section 32063 (:1099, corroborated reaper_plugin_functions.h:3467); Register("custom_action", &ca) returns the command id or 0; idStr must be unique across all sections (:1100). Dispatch for non-main sections MUST come from "hookcommand2" (reaper_plugin.h:212-221) — "hookcommand" runs only for the main section (:200-205), and main.cpp:309 registers only "hookcommand" today. custom_action_register_t carries no ACCEL, so the non-Main entry ships no default keybinding — acceptable; toolbar placement is the ask.

Settled, not a fork: the action registers in BOTH Main and Media Explorer. Ψ.4 asks for reach, not relocation, and a bare move would orphan any existing Main-section keybinding — a half-fix. Because idStr is unique across all sections, the Media Explorer registration mints a second FOREVER-STABLE command-id suffix: INGEST_IMPORT_MEDIA_EXPLORER_MX, composed per channel via channelCommandId like every other id (core/version/app_version.cpp:43-47,84-86) — a new permanent entry in each channel's id family, never to change after shipping. The existing INGEST_IMPORT_MEDIA_EXPLORER string is preserved unchanged for the Main entry, so root CLAUDE.md:180-183's never-change contract is honored literally. Both registrations share the one handler (doImportFromMediaExplorer, ingest.cpp:317-395).

Surface boundary — owns: shell/actions/ingest.cpp (the second registration, the hookcommand2 claim, the -custom_action unload mirror beside the existing mirrors at :476-481), the registration block in src/app/main.cpp (registering the "hookcommand2" hook beside "hookcommand" at :309, and its unload mirror at the rec == nullptr path), and the root-CLAUDE.md §"REAPER extension contract" amendment (the second registration mechanism, documented beside the 4-step main-section pattern). Must not touch: any other action family's registration, panel_*, capture*. T4 must not touch main.cpp; this track is why.

Behavior.

  • Main-section registration byte-identical to today: same id string, same gaccel, same keybindings surviving.
  • Second registration: custom_action_register_t{32063, channelCommandId(new suffix), channelActionName(same display phrase — decided: identical phrase in both sections, for findability), nullptr} via Register("custom_action", ...). A 0 return is tolerated gracefully (the Main entry still works; a console note, not a failure).
  • hookcommand2 claims ONLY the new MX command id and returns false otherwise — hookcommand2 fires for every section including Main, and the Main id stays claimed by the existing hookcommand path (ingest.cpp:470-474 via main.cpp:222-230); the two ids differ, so no double dispatch is possible. Stated as a criterion, not an accident.
  • Unload mirrors everything: -custom_action with the same struct/pointer, alongside the existing -gaccel/-command_id.
  • Beta channel forks both ids automatically through channelCommandId — each channel gains exactly one new permanent id.

Acceptance criteria.

  • The Actions list, section "Media Explorer", shows the channel-prefixed action; it can be added to the Media Explorer toolbar; firing it from that toolbar imports the last played Media Explorer file into a ReaSampler on the selected track — identical behavior to the Main-section entry. [verify — DAW]
  • The Main-section entry is unchanged: same command id, existing keybindings intact.
  • Extension unload unregisters both entries cleanly; reload re-registers both.
  • The new suffix INGEST_IMPORT_MEDIA_EXPLORER_MX is recorded as FOREVER-STABLE, per channel, in the same breath as the registration lands.
  • Root CLAUDE.md's "REAPER extension contract" section gains the non-main mechanism (custom_action / hookcommand2 / -custom_action mirror) — a deliverable of this track.
  • DAW-verification obligation: Daniel adds the action to the Media Explorer toolbar and imports from it; also confirms the Main-section binding still fires. Also: unload, reload, confirm no duplicate Media Explorer entry — the -custom_action unload mirror is unconfirmed against the SDK header (root CLAUDE.md §"REAPER extension contract", [verify — DAW]), and if unsupported the entry leaks across a reload.

Open questions. [verify] re-verify custom_action_register_t and hookcommand2 argument order/types against the SDK headers at implementation time (root CLAUDE.md rule; the section ids and struct shapes above are already header-verified, the rule applies regardless). None classified [propose] — the ruling above is settled.

Ψ-W1-T4 — drop-target-resolution

Goal. Dragging cards out of the panel resolves its target from what is actually under the cursor — continuously, reversibly, with a defined outcome and a visible cue for every surface, and no silent no-op release anywhere. (Ψ.5)

The root causes, so the redesign is judged against them. The current chain locks a drag's fate at its first processed move outside the client rect (core/ui/drag_out.cpp:18-26): a single-card drag over ANY REAPER surface — GetThingFromPoint returns non-empty info for the arrange too (instrument_drop_win.cpp:84-86) — locks to InstrumentDrop and returns before the OS hand-off is ever evaluated (panel_drag.cpp:285-294); over the arrange the info string fails the FX-hotspot rule, so release falls to a silent no-op (root cause A — the verified headline: single-card arrange drops do nothing, while multi-card drags skip the FX resolve (:276) and work via OS drag, which is exactly Ψ.5's "sometimes"). The OsDrag branch is irreversible — ReleaseCapture + resetDragState + modal DoDragDrop (:299-335) — and WM_MOUSEMOVE coalescing makes the deciding exit pixel vary with drag speed (root cause B). The FX "hotspot" is only the FX-button glyph family (fx_*/tcp.fx*/mcp.fx*, core/wire/instrument_drop.cpp:90-95) — TCP body/name, or a TCP too narrow to draw the button, yields "tcp" and a cue-less no-op (root cause C). Multi-card drags can never instrument-drop (root cause D). One unresolvable hand-off evaluation sets dragOsHandoffBlocked for the remainder of the drag (:320, cleared only in resetDragState — root cause E). Coordinate spaces and DPI are NOT causes (verified); bank-to-bank never leaves the client and is CTest-covered (tests/test_drag_out.cpp:33-112) — consistent with "dragging between banks seems fine", and it must stay byte-identical.

The redesign is a gesture law, not a patch. The law: the target class is resolved from what is under the cursor on every move, every class transition is reversible until release or until the pointer leaves REAPER entirely, and the OS hand-off is reserved for leaving REAPER — every REAPER-internal target is executed natively on release. The minimal patch (re-evaluating the hotspot per move but keeping the early irreversible OsDrag fork) is named and rejected: it re-creates root cause B — a drag that crosses the arrange en route to an FX button would still lose the instrument drop forever.

The class enumeration and its defined outcomes (single-card / multi-card):

Under the cursor Single card Multi card
Inside the panel client Internal drag (unchanged, byte-identical) Internal drag (unchanged)
FX hotspot (fx_* window, or track panel — see below) Instrument drop (existing .vstpreset path) Refuse-with-cue (no instrument drop for a multi payload — root cause D becomes a defined, cued outcome)
TCP/MCP, whole panel (not just the FX glyph; *.fxembed still excluded) Instrument drop — decided: the whole track panel is the hotspot. Root cause C IS the FX-glyph-only rule; a capture dropped on a track's panel means "sampler on this track." The rejected alternative — TCP drop = item at edit cursor — is silent-placement-adjacent and has no time coordinate; the arrange owns placement. Refuse-with-cue
Arrange Timeline item at the pointer's track/time — native insertion on release Native insertion, shape at review (see open questions)
Elsewhere in REAPER (ruler, transport, docker chrome) Refuse-with-cue Refuse-with-cue
Outside REAPER entirely OS drag-out (DoDragDrop, CF_HDROP, copy-only — unchanged mechanics, new trigger condition) OS drag-out
  • Every release either performs the resolved action or visibly refuses — the cue (cursor via the existing applyDragCursor precedent, plus the panel's drag paint state) tracks the resolved class continuously, so "will this work" is visible before release, and no cell in the matrix is a silent nothing.
  • The blocked flag is retired as a drag-lifetime latch (root cause E): an unresolvable evaluation refuses that evaluation, not the rest of the drag.
  • The arrange outcome does not violate the load-bearing principle, and the spec says so where a reviewer will look: the item is placed because the USER dragged it to that spot — user-initiated placement, the same class of act as RunInsertSelected, not a capture auto-insert. Root CLAUDE.md's "capture and placement are separate acts" is about capture never placing; a deliberate drop is placement on demand.
  • The pure decision stays pure. The class enumeration, its precedence, and the single/multi split land in core/ui/drag_out (the law) + core/wire/instrument_drop (the info-string classification), CTest-covered over the full matrix; the shell reads live pointer/window state and executes outcomes, exactly the discipline card_drag already follows.
  • Hot-path discipline: the inside-client path stays free of SDK hit-tests (GetThingFromPoint is evaluated only outside the client rect, as today — panel_drag.cpp:273-274); per-move resolution outside the client now runs for multi payloads too, which is new but still per-mouse-move cold.

Surface boundary — owns: core/ui/drag_out (the gesture law, rewritten), core/wire/instrument_drop (classification), shell/panel/panel_drag.cpp (routing + release dispatch), shell/actions/instrument_drop_win.cpp (hit-test shell), shell/actions/drag_out_win.cpp (hand-off trigger timing), tests/test_drag_out.cpp. May touch panel_input.cpp's drag-arm block (:382-402) only — T2's footer block is fenced. Must not touch: src/app/main.cpp (T3's — this track registers nothing), core/ui/card_drag and the in-grid reorder/replace semantics (bank-to-bank stays byte-identical), the capture pillar, the insert action's own semantics.

Acceptance criteria.

  • The full matrix above, DAW-observed, single AND multi: every cell produces its defined outcome with its cue, and in particular — a single-card drop onto the arrange lands an item at the pointer's track and time (the headline defect); a single-card drop onto a track panel (not just the FX glyph) loads the instrument; a multi-card drop onto the arrange still lands items; every refuse cell visibly refuses.
  • Reversibility: leave the client, cross the arrange, reach an FX window → instrument drop still available; return into the panel client → internal drag resumes. One unresolvable evaluation does not change any later evaluation's outcome.
  • Drag speed does not change outcomes: fast flicks and slow drags to the same release point resolve identically (the coalescing hazard is designed out with the early lock, not mitigated).
  • Bank-to-bank drags are byte-identical to today; tests/test_drag_out.cpp:33-112 (or their successors) stay green with unchanged semantics.
  • The pure law's CTest matrix covers every class × single/multi combination, including the *.fxembed exclusions and the null-track/non-empty-info cases the SDK documents for GetThingFromPoint (reaper_plugin_functions.h:3440-3446).
  • No new SDK hit-test inside the client rect.
  • DAW-verification obligation: Daniel runs the matrix, explicitly including the narrow-TCP case (root cause C's trigger), fast-flick drags, and a drag that crosses the arrange before reaching an FX window.

Open questions. [verify] pointer→(track, time) for the native arrange insertion — candidate API GetSet_ArrangeView2 (pixel-column → time mapping) plus GetThingFromPoint's track; verify signatures and behavior against the SDK header before building on them; if no exact pixel→time mapping exists, the arrange outcome's mechanism (not its existence) is re-proposed. [verify] what REAPER does with a CF_HDROP drop re-entering its windows during our DoDragDrop (the accepted residual once the pointer has left REAPER and returns mid-modal-loop — confirm it is REAPER's own file import, then state it). [propose] the multi-card arrange insertion shape (lean: one item per file mirroring REAPER's own multi-file drop convention; alternative: retain the OS hand-off for the multi-arrange cell only — costs a second delivery mechanism and a modal fork, named to be rejected on uniformity unless the native shape fails verification). [propose] the exact refuse-with-cue rendering (cursor-only vs cursor + panel status text).


Ψ-W2 — Names and channels, over the settled render block

Depends on Ψ-W1 — specifically Ψ-W1-T1, which rewrites the capture render-configuration block in shell/capture/capture.cpp and core/capture/render_settings.cpp; both W2 tracks edit adjacent regions of those same TUs, so W2 dispatches only after W1-T1 is on dev. (T2T4 of W1 gate nothing here; the wave boundary is the file collision, not a semantic dependency.)

Two tracks, parallel, disjoint by field family: T1 owns the naming fields (baseName / uniqueTag / displayName / capture_paths), T2 owns the channel fields (channelCount / PCM / wav_codec). The known collision seam, named now: both tracks touch shell/capture/capture.cpp and shell/capture/capture_realtime_finalize.cpp at adjacent lines. In capture.cpp, T1 owns the tag/paths mint (:310-314) and the Sample id/label lines (:398-402); T2 owns RENDER_CHANNELS (:353-354), the new post-render collapse step inserted between the exists-check (:390-395) and the Sample population (:398), and stampCaptureSample's channel echo (:207). In capture_realtime_finalize.cpp, T1 owns the label site (:195); T2 owns the layout-parse/channel lines (:188-198) and the collapse insertion. Adjacent lines, disjoint fields — textual merge adjacency, not semantic contention; whichever lands second rebases.

Ψ-W2-T1 — capture-naming

Goal. Captures are labeled after their source track's name plus a discriminator, on every mint site — and the name is visible where the user looks. (Ψ.1)

Today, and why it reads as broken: every offline capture's displayName is the literal "item" or "track" (CaptureActionDefrender_settings.cpp:175-183capture.cpp:402), the filename is "item_<epoch>-<counter>.wav" (makeUniqueTag, capture.cpp:187-199; deriveBankPaths, core/capture/capture_paths.cpp:48-72) — and the source track name is read nowhere in the tree (repo-wide: zero hits for P_NAME/GetTrackName; the capture path holds MediaTrack* and GUIDs but never a name). Worse, the label barely surfaces: the panel card draws no name at all (panel_render.cpp:23-63 — waveform, bars.beats, seconds.ms only); the sample name appears only inside the VST3 editor. A good name nobody can see is a half-fix, so this track also surfaces it.

Surface boundary — owns: shell/capture/scope_resolve (the ONE place already walking source tracks before the FX-bypass guard — gains the name read, plumbed through ResolvedSource, scope_resolve.h:33), shell/capture/capture.h (CaptureRequest), capture_orchestrator.cpp's naming lines (:229, :405), capture.cpp's mint/label lines (:310-314, :398-402), capture_batch.cpp's mint sites (:220, :284, :395), the realtime label chain (capture_realtime_shell.cpp:309-310, capture_realtime_finalize.cpp:195, core/capture/capture_realtime.cpp:31-32), core/capture/render_settings only for CaptureActionDef::baseName semantics (render_settings.h:170-175 — the literals become fallbacks), and the card name surface: pure geometry in core/ui (bank_grid / card_meta) + its draw in shell/panel/panel_render.cpp. Must not touch: channelCount/PCM/wav_codec (T2's), the render-configuration block W1-T1 landed (read-only here), core/capture/capture_paths's purity — it stays REAPER-free path arithmetic with no filesystem access (core/capture/CLAUDE.md); any collision handling stays makeUniqueTag's, shell-side.

Behavior.

  • The name is resolved shell-side in scope_resolve, before the FX-bypass guard, alongside the GUID walk it already does (scope_resolve.cpp:53-72, :114-127): track scope → the selected track's name; item scope → the selected item's owning track's name. [verify] the read API (GetSetMediaTrackInfo_String with "P_NAME" vs GetTrackName) against the SDK header before use.
  • Label composition: displayName = "<TrackName> <discriminator>". The discriminator's exact format is [propose] (lean: a compact date-time derived from the capture's own createdTimestamp, e.g. Bass 08-01 1432 — Daniel's "date, etc." names it); displayName remains explicitly NOT unique, per the existing rule (core/model/CLAUDE.md §resample_name) — the discriminator serves legibility, not uniqueness.
  • The filename becomes meaningful too: baseName = the sanitized track name, so the stem is "Bass_<tag>.wav" via the existing sanitizeStem + makeUniqueTag pipeline — stem uniqueness remains entirely makeUniqueTag's job, unchanged. A name the sanitizer reduces to nothing (non-ASCII) falls back to "capture" for the stem (capture_paths.cpp:24-46's existing rule) while displayName keeps the real name.
  • Fallback for an unnamed track: deterministic, matching REAPER's own display convention ("Track N" by index at capture time) — never the old literals on the interactive paths.
  • All five mint sites covered, each stated: offline (above); realtime — same resolution at begin time (the action has a selected track); batch — per-unit owning-track name, the batch ordinal retained as an additional discriminator ("Bass 1", "Bass 2"… exact composition settled with the discriminator format); recapture — decided: preserves the existing entry's displayName (it regenerates an entry, it does not mint a new identity; only the file stem re-mints); ingest — unchanged (already meaningful: the source file's stem, ingest.cpp:249-266); bake — unchanged (model::nextIterationName, the Kick r2 precedent). The bake's naming-and-lineage open question is Ξ's, jointly held with Ξ-W1-T1, and this track does not close or touch it.
  • The card shows the name — decided in-scope: one truncated name line on the panel card, geometry pure (bank_grid/card_meta, CTest-covered), drawn by palette role through the kit. Truncation is display-only; the stored value is never shortened. If review finds the card too crowded at the smallest cell size, the fallback is name-in-tooltip — [propose] at review, with on-card as the lean.
  • Existing bank entries are untouched — new captures only; no retroactive rename.
  • displayName already flows to the instrument (component-state copy + one-way refresh, component_state_io.cpp:74-88, sample_map.cpp:96) — no instrument-side work.

Acceptance criteria.

  • An item capture from a track named Bass yields displayName Bass <discriminator> (format as settled at review) and a file Bass_<tag>.wav; a track capture likewise; the literals "item"/"track" never appear as labels on any interactive capture path again. [verify — DAW]
  • Realtime and batch captures follow the same scheme (batch retains per-unit ordinals); recapture preserves the entry's existing name; ingest and bake naming are unchanged.
  • An unnamed source track produces the deterministic Track N fallback.
  • The panel card shows the name, truncated to its cell, pure-geometry tested; the instrument's browse list shows the same name with no mechanism change.
  • File-stem uniqueness is still solely makeUniqueTag's; capture_paths gains no filesystem access; existing entries' labels are byte-identical after the track lands.
  • DAW-verification obligation: Daniel captures from a named track, an unnamed track, and a multi-item selection; sees the labels on the card and in the instrument.

Open questions. [verify] the track-name read API against the SDK header. [propose] the discriminator format (lean above). [propose] multi-track item selections (items spanning several tracks in one capture — lean: first source track's name plus a +N marker; alternatives: joined names, or the scope literal as fallback). [propose] card-name fallback to tooltip only if the card proves too crowded.

Ψ-W2-T2 — mono-collapse

Goal. A new capture whose channels are bit-identical is collapsed losslessly to one channel — one channel of data on disk, a mono arrange item on insert, the instrument loading in Mono mode. (Ψ.6)

The invariant amendment is part of this track. Root CLAUDE.md:208 — "channel count preserved (no silent stereo fold)" — is honored in spirit (the parenthetical forbids a LOSSY fold; this collapse is lossless by predicate) but contradicted in text. The amendment: channel count is preserved except that bit-identical channels may collapse losslessly to mono; a lossy fold remains forbidden. Noted in the amendment: the old text was already untrue in the other direction — a mono source renders at RENDER_CHANNELS=2 today (capture_orchestrator.cpp:227, hardcoded and never measured). [verify — DAW] "lossless" is proven at the file-bytes level; it is not the same claim as the null test's playback-chain property (whether REAPER sums a 1-channel item on a stereo track at the same unity gain as a dual-mono 2-channel item) — see the acceptance criteria's own [verify — DAW] on that bullet below.

Surface boundary — owns: core/capture/wav_codec (the pure bit-identity predicate + collapse plan, with wav_codec unit tests), shell/capture/capture.cpp (the post-render collapse step between the exists-check :390-395 and the Sample population :398, plus stampCaptureSample's channel echo :207 — derive from the FILE, the bake_land.cpp:105,131,177 / ingest.cpp:199,268 precedent), shell/capture/capture_realtime_finalize.cpp (the collapse on the realtime path, and the same echo fix — it parses the layout at :188-198 and STILL echoes the request value), the root-CLAUDE.md:208 amendment, and — minimally, because Phase Γ is live in shell/instrument/shell/instrument/processor_reload.cpp only for the stale "always 2 for extension captures" comment (:64-77 vs :150-157) and any index/file consistency fix that falls out; nothing else instrument-side. Must not touch: the naming fields (T1's), capture_paths, the panel, the instrument's channel-mode logic (sample_map.cpp:58-62 already maps channelCount == 1 → Mono, explicit user toggle winning — no change needed).

Behavior.

  • The predicate is pure and bit-exact: all channels bit-identical per frame (float bit patterns, never epsilon) → collapse to 1 channel. Generalized to N channels (all-identical → mono; no partial collapse, e.g. never 4→2) — N-channel captures are not reachable today (channelCount hardcoded 2), so the generalization is future-proofing the predicate, stated as such.
  • The collapse mirrors the one existing rewrite precedenttrimAutoTailInPlace (capture_realtime_finalize.cpp:55-125): parseWavLayoutextractFloatFramesbuildFloat32Wav(1, …) → truncating rewrite, all with the existing wav_codec tools (wav_codec.h:48-89buildFloat32Wav already takes arbitrary nch). There is no PCM assembly on the offline path today (REAPER writes the file; the extension only stats and hashes it) — this step is the first, and it lives shell-side at the named insertion point with its plan pure.
  • Scope — decided: every extension capture path — offline, realtime, batch, recapture (batch and recapture route through the same backends). Ingest is excluded — imported files are the user's bytes, not our capture; rewriting them is a mutation this tool has no license for. Unconditional, no user opt-out — Ψ.6 asks for the behavior, not a preference; dual-mono stereo carries zero information the mono file lacks. New captures only, never retroactive — existing bank entries and files are untouched.
  • The file and the index value are written together — the stated hazard. A collapsed file with Sample::channelCount left at 2 still plays (the instrument's extractChannel clamps out-of-range to the last channel, sample_map.cpp:174-186, yielding dual-mono) but the mono/stereo toggle and the waveform lane count would read Stereo — so the criterion is equality with the file's fmt on every path, not absence of crashes.
  • Insert needs no change, stated so nobody invents work: insert.cpp:129-152 passes only a path to InsertMedia; REAPER derives the item's channel count from the file — a 1-channel WAV yields a mono item for free.
  • Behavior change, stated and accepted: hashWavContent covers the fmt body + data payload, so a collapsed capture will NOT hash-dedup against a pre-existing stereo twin of the same audio (bank_model.h:143-148). Accepted — the predicate is deterministic, so repeats of the same request still dedup against each other.
  • Bit-identical repeats survive: a deterministic predicate over deterministic bytes; identical requests still produce identical files (now identically-collapsed ones).

Acceptance criteria.

  • A capture of dead-center mono content yields a 1-channel float32 WAV whose PCM is bit-identical to either source channel and whose frame count is unchanged — losslessness asserted by extractFloatFrames equality in the pure tests, observed in the DAW on the real path. [verify — DAW]
  • A capture with ANY differing sample pair is byte-identical to today's 2-channel output — the not-collapsed path is unchanged, the same discipline as "bypassed means byte-identical."
  • Sample::channelCount equals the produced file's fmt channel count on EVERY capture path — including realtime, whose finalize currently parses the layout and echoes the request anyway; that defect is fixed here.
  • Inserting a collapsed capture yields a mono arrange item; the instrument loads it in Mono channel mode with a single waveform lane, explicit user toggle still winning. [verify — DAW]
  • The null test holds for a collapsed capture re-inserted at its source position. [verify — DAW: REAPER's mono-item-on-stereo-track summing at unity is the thing to confirm]
  • Bit-identical repeats hold across the collapse; realtime and batch behave identically to offline; ingest is demonstrably untouched (an imported dual-mono file stays stereo).
  • The predicate + collapse plan are pure with wav_codec test coverage, including the N-channel all-identical case and the one-sample-differs case.
  • Root CLAUDE.md:208 lands amended, in this track; the processor_reload.cpp touch is the comment + consistency fix only.
  • DAW-verification obligation: Daniel captures a dead-center source and a true-stereo source, inserts both, loads both into the instrument, and runs the null test on the collapsed one.

Open questions. [propose] whether bake landings collapse too (lean YES — the bake "writes a file plus an index entry, like every other capture", bake_land already derives channel count from the file, and a dead-center instrument render is exactly the dual-mono case; it is [propose] rather than decided only because bake_land is Ξ-W2's freshly-landed surface and the collapse there should be confirmed against what actually shipped). [verify] REAPER's mono-item summing for the null test (above). Decided, not open: unconditional; new-captures-only; ingest excluded; N-generalized predicate; no partial collapse.


Traceability — all seventeen items

The check that nothing was dropped. Every row points at a track that exists above.

# Item (short) Phase-Wave-Track Worktree slug
1 Envelope editor: radio switch, curve dials, overlay recolor Θ-W3-T2 pth-w3-t2-staged-envelope-curves
2 MM preamp Filter — resonant HP/LP stage Θ-W1-T3 (DSP) + Θ-W2-T1 (integration) pth-w1-t3-filter-dsp-port, pth-w2-t1-filter-voice-path
3 Alternative Spline EGs Θ-W5-T1 pth-w5-t1-spline-egs
4 Bug: end-of-sample click, Trigger × Preserve Θ-W3-T2 pth-w3-t2-staged-envelope-curves
5 Bug: drag-out sometimes lands without audio Θ-W1-T2 pth-w1-t2-capture-handoff-bugs
6 Bug: FX-container drop loses the capture Θ-W1-T2 pth-w1-t2-capture-handoff-bugs
7 Stereo waveform shows both channels Θ-W2-T2 pth-w2-t2-stereo-waveform-lanes
8 Release anchoring; the Pitch AD becomes AHD Θ-W3-T2 pth-w3-t2-staged-envelope-curves
9 Loop points — regression + Gate loop-sustain Θ-W4-T1 pth-w4-t1-gate-loop-sustain
10 Knob/label sizing, ms units, double-click reset Θ-W6-T1 pth-w6-t1-legibility-and-antialiasing
11 Preview glyph; VELOCITY deck; bipolar curves Θ-W4-T2 pth-w4-t2-velocity-deck-and-bipolar-curves
12 Toolbar cleanup; full-width piano strip; tooltips Θ-W2-T3 pth-w2-t3-toolbar-and-piano-strip
13 Antialiased rendering audit for high-DPI Θ-W6-T1 pth-w6-t1-legibility-and-antialiasing
14 Trigger amp/filter fade → AHD consolidation Θ-W3-T2 pth-w3-t2-staged-envelope-curves
15 One-click in-sampler resample Ξ-W1-T2 (note model) + Ξ-W2-T1 (bake chain) + Ξ-W3-T1 (popup) pxi-w1-t2-note-program-model, pxi-w2-t1-resample-bake-chain, pxi-w3-t1-capture-signal-popup
16 Retire the zone mapping system Θ-W1-T1 pth-w1-t1-zone-retirement
17 Consolidate provenance/usage tracking Ξ-W1-T1 pxi-w1-t1-tracking-consolidation

Work in this plan that is not one of the seventeen

The table above is a completeness proof over TODO-1.0.md — every row points at a track, so nothing from the source was dropped. It is deliberately not an index of the plan: work that did not come from the source doc has no row, and inventing one would weaken the proof it exists to give.

  • Θ-W3-T1 — live-parameter-delivery (pth-w3-t1-live-parameter-delivery). Arose from Θ-W2-T1's implementation review, not from TODO-1.0.md. The first such track in this plan; see Θ-W7-T1 below for the second.
  • Θ-W7-T1 — arc-and-spline-aa (pth-w7-t1-arc-and-spline-aa). Opened after Θ-W6-T1 shipped, when Daniel found two rendering defects by eye in the editor — not from TODO-1.0.md, and not a track this plan originally scoped. The second such track in this plan today; if others appear, they belong on this list rather than in the table.
  • All of Phase Γ (pg-*). Ten tracks across four waves, from a direct interview with Daniel (2026-08-01) and his four later rulings the same day, not from TODO-1.0.md. Listed here as a block rather than per track, because the whole phase is outside the source doc; the product reasoning lives in docs/product/instrument-control-surface.md and the parameter system's in docs/product/parameter-automation.md §§610. Two docs/TODO.md entries are discharged by this phase, not deferred again: Γ-W3-T1 discharges the deck-rework entry (whose original "one row of taller decks with within-deck stacking" shape Daniel explicitly superseded), and Γ-W1-T1 discharges "Raise the stage-time ceiling above 2 s" (Γ-F3 reversed).
  • All of Phase Ψ (ppsi-*). Six tracks across two waves, from a direct list of seven defects and refinements (Daniel, 2026-08-01), not from TODO-1.0.md. Listed here as a block, like Γ; unlike Γ it has no backing product doc — the seven are recorded verbatim in the phase header as its provenance (Ψ.1–Ψ.7), and the design content lives inline in its tracks.
  • Γ-W3-T2 bake-reset-amendment is a CORRECTION, not a feature, and belongs on this list for a different reason from the others: it exists only because Ξ-W2-T1 shipped ahead of this plan's sequencing claim. If more corrections of this shape appear, they belong here rather than in the table — the table is a completeness proof over TODO-1.0.md, and a correction has no source row to point at.

Deliberate compressions

Recorded so a reader of TODO-1.0.md can see what this plan did to the source, rather than discovering it later:

  • Item 2 is split across two waves. The DSP port (Θ-W1-T3) is deliberately separated from the integration (Θ-W2-T1) so the external-input dependency on Daniel's Cortex-M4 code sits on a standalone, disjoint track instead of blocking a wave. Item 2's acceptance criteria are split accordingly — the range/resonance assertions land in W1-T3's tests, the audible/pipeline/deck criteria in W2-T1.
  • Item 2's filter envelope ships twice. W2-T1 ships it in the existing staged AHDSR shape; W3-T2 gives it the curve treatment and the mode-driven Gate→AHDSR / Trigger→AHD shape. This is deliberate: waiting would put the filter behind the whole envelope system.
  • Item 4 lands in Θ-W3, not Θ-W1. Its fix region is the region item 14 retires, and the only earlier instrument-side track owns the entire engine. Its acceptance gate is stated as the post-consolidation gate. It is not gated behind the whole editor chain — three waves of six — and the source doc itself requires re-verification under the surviving mechanism either way.
  • Item 11's filter velocity curve is split from item 2's filter velocity modulation. W2-T1 wires the modulation path (following the amp/pitch precedents); W4-T2 sets the curve's bipolar domain and default and homes its button. Neither track can do the other's half.
  • Item 15's undo/recovery is carried as a note, not a criterion — Daniel set it at exactly "a plus." The guaranteed recovery floor (the superseded file surviving until prune) is a criterion.
  • Nothing else was compressed. Every other item's behavior bullets and acceptance criteria are carried at full strength into the track that owns it.

Outline at a glance

Phase Θ — ReaSampler 9000: one parameter set, filter, shapeable envelopes, legible editor
  W1  Collapse and re-seam
      T1 zone-retirement ......................... 16
      T2 capture-handoff-bugs .................... 5, 6
      T3 filter-dsp-port ......................... 2 (DSP)      [needs Daniel's M4 code]
  W2  Filter in the voice path; waveform and chrome bands
      T1 filter-voice-path ....................... 2 (integration)
      T2 stereo-waveform-lanes ................... 7
      T3 toolbar-and-piano-strip ................. 12
  W3  Live parameters, then the staged envelope system      [T1 before T2 — serial]
      T1 live-parameter-delivery ................. (not one of the seventeen)
      T2 staged-envelope-curves .................. 1, 8, 14, 4
  W4  Loop sustain and the velocity deck
      T1 gate-loop-sustain ....................... 9
      T2 velocity-deck-and-bipolar-curves ........ 11
  W5  Spline EGs
      T1 spline-egs .............................. 3
  W6  Editor legibility pass
      T1 legibility-and-antialiasing ............. 10, 13
  W7  Arc-and-spline antialiasing fix
      T1 arc-and-spline-aa ....................... (not one of the seventeen)

Phase Ξ — The resample loop            (W1 concurrency-safe with Θ from Θ-W2 onward)
  W1  Consolidated tracking, and the programmed-note model
      T1 tracking-consolidation .................. 17
      T2 note-program-model ...................... 15 (model)
  W2  The bake chain            [ran AHEAD of Γ; its reset list is corrected by Γ-W3-T2]
      T1 resample-bake-chain ..................... 15 (chain)
  W3  The capture-signal popup
      T1 capture-signal-popup .................... 15 (popup)

Phase Γ — The instrument's control surface      (none of the seventeen; ends with VST3 params)
  W1  Foundations                            [5 tracks, disjoint by surface]
      T1 knob-interaction-law ....... modifiers + ONE taper module + reset bypass
                                      + 10 s ceiling + AHDSR schematic axis   [Ruling 2]
      T2 master-bus-audio ........... limiter + meter ballistics + dynamic PDC [rung 1]
      T3 contour-trace-curves ....... staged traces draw curved, knot on its trace
      T4 editor-floor-and-row-law ... floor 1190x680 + budget constants + row predicate
      T5 preserve-time-stretch ...... real stretcher      [measure-and-report gate]
  W2  New controls, and the overlay's marks  [2 tracks]
      T1 pitch-rate-deck ............ Rate + Pitch, Varisp/Presrv compounding  [rung 2]
      T2 loop-crossfade-ux .......... four-mark grammar; fade painted where it is heard
  W3  The reflow, and the bake correction    [2 tracks]
      T1 deck-reflow ................ two rows + double-height MASTER, by construction
      T2 bake-reset-amendment ....... the Xi correction Gamma owns  [needs Xi-W2-T1 on dev]
  W4  VST3 parameters                        [1 track]
      T1 vst3-parameter-set ......... 44 derived params, frozen id table     [Ruling 1]
                                      [rung 3 RESERVED, spent only if verify says so]
                                      [OPEN: Gamma-F7, the parameter order — Daniel]

  Resequenced 2026-08-01, three times: the reflow split canvas (W1-T4) from arrangement
  (W3-T1); preserve-time-stretch moved W4 -> W1-T5, retiring Rate's interim stand-in; then
  Ruling 1 added W4 and Ruling 2 grew W1-T1.
  Payload rungs are RELATIVE, not absolute — read kParamsPayloadVersion on dev and take the
  next three above it. On dev at 2026-08-01 that is v14 / v15 / v16-reserved.
  Shared files, named: engine/CMakeLists.txt (W1-T2 | W1-T5), ui/CMakeLists.txt
  (W1-T1 | W1-T3), editor_session.cpp (W2-T1 | W2-T2) — all textual adjacency, not
  semantic contention. W3-T2's disjointness from W3-T1 is CONDITIONAL: confirm it against
  what Xi-W2-T1 shipped, and serialize behind T1 if it does not hold.

Phase Psi — The extension trust pass          (none of the seventeen; a direct list of seven)
  W1  Exact bounds, disciplined switches, reachable actions, resolved drops  [4 tracks]
      T1 capture-range-exactness ..... Psi.7   [opens with a DAW repro matrix]
      T2 mode-switch-discipline ...... Psi.2 + Psi.3   [one chokepoint: applyMode]
      T3 media-explorer-section ...... Psi.4   [BOTH sections; new FOREVER-STABLE id]
      T4 drop-target-resolution ...... Psi.5   [gesture law, not a patch]
  W2  Names and channels, over the settled render block   [gated on W1-T1's render block]
      T1 capture-naming .............. Psi.1   [+ the card shows the name]
      T2 mono-collapse ............... Psi.6   [lossless only; ingest excluded]

  Three invariant amendments are track deliverables: never-touch-solo (W1-T2, three
  files), the action-registration contract (W1-T3, root CLAUDE.md), channel-count-
  preserved (W2-T2, root CLAUDE.md:208).
  Shared files, named: panel_input.cpp (W1-T2 footer block | W1-T4 drag-arm block);
  capture.cpp + capture_realtime_finalize.cpp (W2-T1 naming lines | W2-T2 channel
  lines) — all textual adjacency, not semantic contention. main.cpp is W1-T3's
  exclusively.