xtc/docs/WORKSPACE.md

Flat DAW workspace

Phase 33 presents the existing xtc editors in a consistent flat workspace. It uses FLTK vector drawing and system fonts: no images, shadows, bevels, 3D rendering, external theme packages or new runtime dependencies.

The default window is 1280 × 800; the supported minimum is 1220 × 720. The main editor grows with the window. Use the scrollbars for longer arrangements and larger track counts. The sidebar stays available across Sequencer, Mixer and Modular Graph views. Ctrl+1/2/3 switches those views; Ctrl+4 opens the piano roll.

Create and arrange

• New MIDI track (Ctrl+Shift+M) creates a named track and a one-bar MIDI clip at the cursor. The new clip and mixer track are selected together. Edit MIDI notes opens its piano roll. Creation is one undo step.
• New audio track (Ctrl+Shift+A) creates an empty named track. Import WAV imports into the selected track, or creates one when none is selected.
• Load instrument plugin opens the instrument browser for the selected sequencer track. Unassigned MIDI tracks retain the built-in sine instrument.
• Existing Add track/region/MIDI clip, duplication, trimming, split, rename and delete commands remain available. F2 renames the selection. Drag clips to move them and their edges to trim them; click the ruler to seek while stopped.

Creating a track uses candidate preparation, so module, capacity or allocation failures retain the current project. As with other project replacements, the engine stops and the transport returns to the beginning. Track creation is unavailable while recording. No track type restriction is added to the model: ordinary tracks still accept the existing audio and MIDI workflows.

Track headers show a stable color, name, order and mute/solo state. Clip colors follow track identity through reordering. MIDI previews show real note starts, durations and relative pitches; waveforms continue to show loaded audio data. The selected clip has a light outline. A teal playhead and bar grid make musical time visible. The transport display reads bar : beat : tick (4/4, 960 ticks per beat); BPM follows the project tempo. These displays are read-only.

The sidebar inspector follows the sequencer selection, showing track name, gain/pan, mute/solo and assigned instrument. Use the Mixer for controls, routing, meters and automation; the sidebar is an overview, not another mixer. Status and errors remain visible below the editor. Existing engine connection, transport, recording and keyboard safety behavior is retained.

Example and verification

Open examples/projects/modern-session.xtc for an original four-track, four-bar MIDI arrangement with 16 clips and 128 notes. It needs no media or plugins. It is also installed with the project examples. Connect JACK playback ports before listening. Work on a copy if the installed examples are read-only.

GUI tests exercise sidebar creation, selected clip/editor access, undo/redo, failed preparation, save/reopen and layout at 1220 × 720 and 1600 × 1000. The running example was also inspected at 1280 × 800. Existing GUI plugin, live JACK and workflow tests cover the retained commands. A modern presentation does not add commercial-DAW features: detachable/resizable docks, mixer channel strips, automatic plugin scanning, custom plugin editors and new audio/MIDI features remain outside this phase. Existing plugin and engine limits still apply.

Phase 34 editing controls

The Snap dropdown above the sequencer selects Off, 1/32, 1/16 triplet, 1/16, 1/8 triplet, 1/8, 1/4, 1/2 or one bar. Existing View/Snap commands update the same preference. Bar lines are strongest, beats medium, subdivisions subtle. At low zoom closely spaced lines are coarsened to at least six pixels; snapping still uses the selected division. Clip moves and trim boundaries snap to the nearest absolute grid position (halfway rounds forward), including clips that start off the grid. Off removes musical quantization; pointer resolution and integer model ticks still apply. Invalid trims retain the original clip. Snap is a UI preference, not a project edit or a saved project setting.

Double-click a MIDI clip with the left mouse button to open its piano roll. The clip is selected and the click does not move/trim it. Audio/silent clips retain their existing selection/drag behavior. The piano roll also has a Snap dropdown for its existing note grid; sequencer and piano snap remain independent.

The piano roll has a fixed Velocity lane beneath the keys and a Note velocity slider. Select a note, then drag its bar vertically or release the slider at a value from 1 to 127. Only that note changes; pitch, timing, length, channel and other notes stay intact. One completed drag/slider edit is one undo step; Escape cancels a lane drag. For chord notes sharing a start time, select the desired note in the keys first; its highlighted velocity bar and slider remain individually editable. Horizontal scrolling aligns the lane with note starts; vertical scrolling moves the keys while the lane stays available. Filters apply to lane visibility and selection. Values save with existing note metadata and affect built-in synthesis; plugin patches determine velocity response. This is MIDI velocity, not a per-note audio gain or loudness meter.

Every ordinary track header has an instrument dropdown. Choose Built-in sine, an instrument already assigned elsewhere in the project, or Load plugin... for a trusted CLAP/VST2/VST3 binary. Entries show the format and plugin label. Each assignment creates an independent track instance, selects that track for live MIDI and remains undoable; clear/reorder/reopen use stable track IDs. Bus tracks show their bus label instead. Cancel or failed preparation restores the model's selection in the dropdown. The list is project-local, not a scanner or installed-plugin database. Existing mono/default-configuration host limits apply. Instrument changes stop/reprepare playback and are refused while recording.

Verification includes off-grid move/trim, snap Off, dropdown labels, double-click, coincident notes, per-note slider/lane edits, invalid velocities, undo/reload and instrument reuse/clear/reorder for all three fixture formats. Manual checks use the original modern-session example and the flat sequencer/piano windows.