OCCTSwiftInteraction

Identity, selection, and the assembled CAD viewport service for the OCCTSwift stack.

Part of the OCCTSwift ecosystem.

Status: 0.x, heading for 1.0.0 once the picking consolidation (ecosystem#43) has landed and settled.

Three targets, one package

OCCTSwiftTools      kernel-to-renderer bridge: Shape into ViewportBody with picking metadata,
                    plus the identity tables that give a picked ordinal a durable
                    topological identity. No UI framework of any kind.
  └─ OCCTSwiftAIS   interactive services: selection state, modes, schemes, filters, area
                    selection, manipulator widgets, dimensions. Modeled on OCCT's own AIS_*.
       └─ OCCTSwiftCADKit    the assembled SwiftUI CAD viewport service: import, picking,
                             clipping, camera framing.

import OCCTSwift
import OCCTSwiftTools

let box = Shape.box(width: 10, height: 5, depth: 3)!
let body = ViewportBody.from(box)!

Why one package instead of three

These were three repositories until ecosystem#42. The boundaries between them are real; the packaging of them was not. Three version lines that only ever moved together, three release cuts that had to happen in strict order, three CI setups. A single cross-cutting change needed six sequenced pull requests across three repositories with a release between each. OCCTSwiftTools was 1,123 lines across 9 files, carrying more repository overhead than code.

The merge does not collapse the modules. Each is still a SwiftPM target, so the layering stays enforced by the compiler exactly as strictly as it was across package boundaries. Depending on this package does not pull SwiftUI into a headless build: SwiftPM compiles only the targets reachable from the products you name, and OCCTSwiftTools imports no UI framework.

This follows OCCTSwiftUX, which has vended six targets from one package since well before this.

Migrating

Your import lines do not change. See docs/MIGRATION.md.

Documentation

• docs/MIGRATION.md, moving from the three old packages
• docs/reference/, per-type reference across all three targets
• docs/guides/, getting started and cookbook
• Historical changelogs: OCCTSwiftTools, OCCTSwiftAIS

Face identity

Face identity keys on OCCT's TopoDS_Shape::IsSame: same TShape, same Location, orientation may differ (#1). So faces(), the enumeration deduplicated through TopTools_IndexedMapOfShape, is what FaceIdentityTable is built from, and a face shared between two shells is one selectable thing rather than two. A caller that needs to know which use of a shared face was picked reads orientation off the returned shape, which is how OCCT answers the same question.