xtc/docs/CREATIVE_WORKFLOWS.md

# Creative workflow additions (Phases 90–99)

These features prioritize fast musical experiments and retain the existing
control-thread preparation and project undo model. They introduce no dependency
or project-format change. Each phase is qualified separately in ROADMAP.md.

## Selected track inserts

**Track → Show selected track inserts** (Ctrl+5) opens the sequencer or active
mixer selection directly. Bus inserts are unsupported; no selection leaves the
workspace unchanged. **View → Track inserts** still opens the rack independently.
Ctrl+4 remains the piano-roll command, resolving the earlier shortcut collision.

## Duplicate an effect

Select a slot, then **Rack actions → Duplicate effect**. The copy appears directly
after it, retaining controls, automation, wet amount and bypass. It is an
independent instance with fresh processing history. Eight-slot capacity and
plugin preparation errors preserve the old chain; Undo removes the copy.

## Copy a chain between tracks

**Rack actions → Copy chain** stores an independent metadata snapshot. Select
another track and use **Paste chain (replace)** to replace its complete chain,
including output gain. Copying neither loads modules nor changes undo history;
pasting prepares the candidate and is undoable. The clipboard is internal to
this session and clears on successful New/Open. Preparation errors keep both
the destination and clipboard intact.

## Compare effect configurations

**Rack actions → Compare** captures or recalls A and B. Each slot is bound to the
track where it was captured; Recall is available only on that track. Capturing
copies metadata without affecting undo or loading modules. Recall prepares a
fresh chain and is undoable; histories and opaque plugin states are excluded.
The two comparison slots clear on successful New/Open. Comparisons stop
transport when recalled, following the existing safe insert-edit workflow.

## Creative starting points

**Add effect → Templates (replace)** offers Slapback (80 ms delay), Dub Echo
(375 ms feedback delay into a short reverb), and Ambient Space (long reverb into
500 ms delay). They replace the current chain in one undoable edit and require
no external plugins. All controls remain editable. Times are milliseconds;
feedback and wet levels are deliberate starting points, without automatic
loudness matching or a claim that the presets suit every source.

## Bulk rack actions

**Enable all effects**, **Bypass all effects**, and **Clear chain** each prepare
one undoable edit. Enabling all intentionally enables every slot, including
previously bypassed effects; Undo restores the previous mixed bypass state.
Clear removes slots while preserving chain output gain. No plugin resources
are released in the audio callback. Empty racks return a no-result error.

## Meter while editing effects

The insert workspace shows the selected track's stereo sample peaks after its
fader and before its bus, including the effects' output. Green bars release at
20 dB/s. A sticky red CLIP appears at unity or above; click the display to clear
it. Stopped, offline or missing-track readings show the -90 dBFS floor. Changing
tracks clears the indicator. These are sample peaks, not true-peak or loudness
measurements. The display shares the mixer's existing backend snapshot read.

## Tap tempo

Tap the transport **Tap** button at a quarter-note pulse. The estimator averages
the last four valid intervals and accepts 20–300 BPM. The first tap primes it;
a pause longer than three seconds restarts it. Too-fast or backward timestamps
are ignored. Each accepted tempo is an undoable edit and stops playback before
preparation; tapping is unavailable while recording. New/Open resets tap history.
The estimator uses monotonic control-thread time, with no audio-callback clock
access or allocation. Tap timing is not a beat detector or MIDI clock sync.

## Audio crossfades

Select two partially overlapping audio clips on the same track and choose
**Edit → Audio tools → Crossfade two selected clips**. The earlier clip fades
out across the overlap while the later clip fades in. Gains, positions, source
files and the opposite fades are preserved. Equal boundaries, containment,
adjacency, cross-track selections and MIDI clips reject without partial edits.
This is a linear tick-based crossfade using existing clip envelopes; it does
not move clips, create overlaps or offer equal-power curves. Discrete sample
endpoints retain the engine's existing one-sample boundary convention.