Instruction file imported from Brian-scott-bean/ChromaGlow (.cursor/rules/composer.mdc). Copyright stays with the author.

Composer Feature Rules

What's Already Built (DO NOT RECREATE)

• CompositionModels.swift — PaletteConfig, MotionConfig, EnvelopeConfig, ReactionConfig, CodableColor, CompositionPreset
• CompositionEngine.swift — CompositionEngine.render() + CompositionParamBox
• CompositionStore.swift — JSON persistence + 66 built-in presets
• StudioViewModel.swift — .composition(presetID:) strategy + composerStudioCards
• UnifiedOrchestrator.swift — startCompositionMode() with DTLS 25fps / REST 5fps

Key Pattern: Live Slider Updates

Sliders write DIRECTLY to activeCompositionBox:

vm.activeCompositionBox?.palette.saturation = newValue

No debounce. No API call. The render loop reads the box each frame (25-50fps).

activeCompositionBox is a get-only, selection-derived accessor over activeCompositionBoxes: [StudioSelectionKey: CompositionParamBox] — it returns the box for the CURRENTLY SELECTED room (StudioSelectionKey(room:)). Mutation works because CompositionParamBox is a class. There is no single global box: two rooms running compositions at once own separate boxes, and callers holding only bridge + group id resolve through the fail-closed unique-match helper.

Preset Categories

• .ambient — Slow, warm, relaxing (Sunset, Ocean, Aurora, Cozy, Heartbeat)
• .energetic — Fast, vivid, reactive (Bass Drop, Club Mode, Storm Chase)
• .holiday — Seasonal with seasonMonths field (Christmas, Halloween, Valentine's, etc.)
• .myCreations — User-saved compositions

Built-in Preset IDs

Built-in presets use deterministic UUIDs (00000001-... through 00000009-...). Never generate random UUIDs for built-ins.