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Horatio

Horatio — Claude Context

Zero-dependency foundation package. Defines the types that all other packages (Enobarbus, Ariel, Touchstone) depend on. No framework imports beyond Foundation, CoreGraphics, and CoreMIDI (AVFoundation only for #if canImport guards).

What Lives Here

InputSource.swift — The core protocol and all concrete source types: - InputSource protocol: id, type, isActive, position (0–1 normalized), intensity (0–1), metadata - HandInputSource — wrist position + finger count + chirality - TouchInputSource — multi-touch slots (always active; inactive = removed) - BodyJointInputSource — 19 body joints with confidence - FaceLandmarkInputSource — face landmarks + expression coefficients - RelationshipInputSource — derived from two sources (distance, angle, delta) - DepthEnrichedInputSource — wraps another source with Z-depth - Legacy EyeInputSource / MouthInputSource — prefer FaceLandmarkInputSource - TrackerCapability enum — vision capabilities (handPose, bodyPose2D, etc.) + ARKit capabilities (arkitFace, arkitBody) + hardware (trueDepth, lidarDepth, multiCam) - TrackerCapabilities struct — runtime detection via available, available(for:) (iOS-only hardware checks)

MIDITypes.swift — MIDI routing and message types: - MIDIRoute — binds a source ID to channel + mapping mode + scale + note range - MappingMode — .notes(axis:), .controlChange(cc:), .pitchBend, .velocity, .depth(cc:) - Scale enum — 12 musical scales with intervals arrays - MIDIMessage enum — noteOn/Off, CC, pitchBend, pressure, programChange - RoutedMIDIMessage — message tagged with source ID - midiToHz() — MIDI note number to Hz conversion (A4 = 440 Hz)

MIDIPacketParser.swift — Raw MIDI packet parsing (moved from Ariel): - ParsedMIDIEvent — parsed channel voice event (status, channel, data1, data2) - MIDIPacketParser — parses MIDIPacket into [ParsedMIDIEvent], handles all channel voice messages (0x80–0xEF)

Source ID Conventions

  • Hands: leftHand, rightHand, leftHand2, rightHand2
  • Body: body.{joint} (e.g., body.leftShoulder, body.root)
  • Face: face.{landmark} (e.g., face.leftEye, face.mouthOpen, face.yaw)
  • Relationships: rel.{metric} (e.g., rel.kneeDistance)
  • Depth: matches underlying source ID
  • Touch: touch0–touch3

Rules

  • No framework dependencies. This package must stay importable by everything — no AVFoundation, UIKit, Vision, ARKit.
  • Hardware detection (isTrueDepthAvailable, isLiDARAvailable) is behind #if os(iOS).
  • Adding a new InputSourceType or TrackerCapability case affects all downstream packages — check Enobarbus trackers and app-level switch statements.
  • All source types are value types (structs/enums) and most conform to Equatable.

Tests

cd Packages/Horatio && swift test
Test files: MIDIRouteTests, InputSourceTests, ScaleTests.