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OCCTSwift

OCCTSwift Wrapping Status

Coverage

All user-facing OCCT classes are wrapped to method-level completeness: 4,256 operations across 1,166 OCCT headers the bridge includes (of 6,774 shipped in the xcframework).

Both numbers are derived, not maintained by hand: the first is python3 Scripts/count-operations.py’s DERIVED row, which the count-operations gate holds README.md and docs/API_REFERENCE.md to. It does not yet hold this file, which is how the figure here sat at 3,333 from 2026-04-13 until v2.0.0 while the real count grew past 4,200.

What’s Wrapped

Every OCCT toolkit used for modeling, analysis, and data exchange:

  • TKernel / TKMath: Standard, math solvers (Matrix, SVD, BFGS, PSO, GlobOptMin, Newton), OSD utilities
  • TKG2d / TKG3d: Full Geom2d and Geom class coverage (curves, surfaces, all methods)
  • TKGeomBase: GeomLib, GeomConvert, GCPnts, Adaptor classes
  • TKGeomAlgo: GeomFill, GeomPlate, NLPlate, FairCurve, LocalAnalysis, Approx, GccAna, Intf
  • TKBRep / TKTopAlgo: BRepBuilderAPI, BRepLib, TopExp, BRep_Tool, TopoDS_Builder
  • TKPrim: All primitive builders
  • TKBO / TKBool: BOPAlgo (Splitter, CellsBuilder, BuilderFace/Solid), IntTools
  • TKFillet: Fillet, chamfer (2D and 3D), FilletSurf
  • TKOffset: Offset, thick solid, draft, simple offset
  • TKFeat: Feature-based modeling (prism, revolve, pipe, split, glue)
  • TKShHealing: ShapeFix, ShapeAnalysis, ShapeUpgrade, ShapeConstruct, ShapeCustom, ShapeBuild
  • TKMesh: BRepMesh, Poly_Triangulation, Poly_Connect
  • TKHLR: Hidden line removal (HLRBRep, HLRAlgo)
  • TKXSBase / TKDEIGES / TKDESTEP / TKDEOBJ / TKDEPLY / TKDESTL / TKDEGLTF: All I/O formats
  • TKLCAF / TKCAF / TKCDF / TKXCAF: Full OCAF framework (TDF, TDataStd, TDataXtd, TFunction, TNaming, XCAFDoc)
  • TKV3d: Quantity_Color, Graphic3d materials

What’s Not Wrapped (by design)

Category ~Count Reason
STEP/IGES internals ~1,700 Internal protocol/model classes, not user-facing
Visualization/OpenGL ~500 OCCTSwift targets Metal via OCCTSwiftViewport, not OCCT’s OpenGL viewer
NCollection containers ~900 Template-only C++ (no exported symbols); used internally in bridge
Abstract base classes ~200 Cannot be instantiated; only concrete subclasses are wrapped

Classes Not Wrapped (require abstract subclass implementations)

These require implementing C++ abstract classes, which the bridge architecture doesn’t support:

  • ChFi3d_FilBuilder, ChFi3d_ChBuilder — complex stateful builders with protected virtuals
  • Approx_FitAndDivide, Approx_FitAndDivide2d — need AppCont_Function abstract impl
  • BRepBlend_AppSurface — needs Approx_SweepFunction abstract impl

Classes Not Wrapped Directly (reached only through another wrapper)

  • ShapeFix_Shell — no bridge function constructs one. Shell repair is reached through ShapeFix_Shape, which drives ShapeFix_Shell internally; the header is #included by the bridge’s umbrella translation unit but never used. The cross-reference index in OCCTBridge.h claimed an OCCTShapeFixShell wrapper until #510 measured it and removed the entry. Wrapping it directly would mean exposing per-shell orientation/mode control (FixFaceOrientation, SetNonManifoldFlag) that ShapeFix_Shape currently chooses for the caller.
  • ShapeUpgrade_ConvertCurve3dToBezier, ShapeUpgrade_ConvertSurfaceToBezierBasis — reached through ShapeUpgrade_ShapeConvertToBezier, the shape-level driver that owns both. The index entries carry a (via …) aside naming that driver.
  • BOPAlgo_RemoveFeatures — reached through BRepAlgoAPI_Defeaturing, a forwarder to it. #536 deleted the direct wrap that duplicated the forwarder.
  • LProp_AnalyticCurInf — OCCTLPropAnalyticCurInf fills a LProp_CurAndInf from an inline scan of the analytic curve types rather than constructing the OCCT class.

Classes Not Wrapped At All

  • Geom2d_Direction, Geom2d_VectorWithMagnitude — the headers are #included but never used. OCCTDirection2D* and OCCTVector2D* are gp_Dir2d/gp_Vec2d arithmetic on bare doubles, not wrappers for the Geom2d_ handle types; the cross-reference index claimed otherwise until #565 measured it. Wrapping them would mean exposing a reference-counted handle for what is currently a value-type calculation.

Constraint Solver Infrastructure (Complete)

All priority items from the original gap analysis are now wrapped:

  • P1 Math solvers: math_FunctionSetRoot, math_BissecNewton, math_BFGS, math_Powell, math_Matrix, math_SVD, math_Householder, math_PSO, math_GlobOptMin
  • P2 Batch evaluation: GeomEval grid evaluators, EvalD0/D1/D2/D3 for curves and surfaces
  • P3 Adaptor classes: Geom2dAdaptor_Curve, BRepAdaptor_Curve, BRepAdaptor_Surface exposed
  • P4 Geometry analysis: GeomLProp, BRepLProp, GCPnts_AbscissaPoint, ShapeAnalysis
  • P5 Topology exploration: TopExp_Explorer, BRep_Tool, TopTools maps