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OCCTSwift

OCCT Upgrade History

Documents breaking changes and migration steps for each OCCT version upgrade.

Version Timeline

OCCTSwift OCCT Version Date Notes
v1.0.0 8.0.0 GA May 2026 Current — SemVer-stable; PointSetLib removed, EdgeRegularity consolidated
v0.170.x 8.0.0-beta2 May 2026 Last pre-GA release
v0.157.0 8.0.0-beta1 May 2026 BRepGraph BuilderView → EditorView reshape
v0.128.0+ 8.0.0-rc5 Apr 2026 Analytical geometry, thread safety improvements
v0.27.0 8.0.0-rc4 Feb 2026 111 improvements, 4 breaking changes
v0.26.0 8.0.0-rc3 Feb 2026 Initial OCCT 8.0 adoption
v0.16.0 7.8.1 Feb 2026 Original release

Beta2 to GA (v0.170.x → v1.0.0)

Breaking Changes

Change Migration
PointSetLib_Props / PointSetLib_Equation removed Module rolled back before GA. Swift PointSetLib enum + bridge wrappers deleted. No upstream replacement — port consumers to NumPy/Accelerate.
BRepGraph::EditorView::CoEdgeOps::SetContinuity removed Replaced by EditorView::EdgeOps::SetRegularity(edge, face1, face2, continuity). Continuity now lives on BRepGraph_LayerRegularity (per (edge, face1, face2)), not per coedge.
BRepGraph::EditorView::CoEdgeOps::SetSeamContinuity removed Use SetRegularity(edge, face, face, continuity) — face1 == face2 expresses seam continuity across a closed-surface seam.
BRepGraph::EditorView::CoEdgeOps::SetSeamPairId removed No setter — seam-pair-id is structural in GA (two coedges on same (edge, face) with opposite orientations). Read via BRepGraph_Tool::CoEdge::SeamPair.
TopTools_IndexedMapOfShape deprecated (warning only) Use NCollection_IndexedMap<TopoDS_Shape, TopTools_ShapeMapHasher>. Not yet migrated; warning is non-blocking.
Standard_True / Standard_False deprecated (warning only) Use C++ true / false directly. Bridge call sites flagged but not yet migrated; warnings non-blocking.

New APIs in GA

The headline GA additions (BRepGraph, Gordon Surfaces, TKHelix, ExtremaPC) all landed in earlier RCs/betas and are already wrapped. GA itself was a stabilization release — see OCCT discussion #1275.

Stability

  • STEP read/write: now safe under the contract of one reader or writer per thread (per the GA announcement).
  • SEGV fixes: chamfer, fillet, and pipe-shell operations received multiple stability patches in the rc5→GA window.

OCCTSwift API consolidation in v1.0.0

Pre-1.0 v1.0.0
setCoEdgeContinuity(_:continuity:) setEdgeRegularity(_:face1:face2:continuity:) -> Bool
setCoEdgeSeamContinuity(_:continuity:) setEdgeRegularity(_:face1:face2:continuity:) (face1 == face2)
setCoEdgeSeamPairId(_:seamPairCoedgeIndex:) Removed — seam-pair-id is structural; read via coedgeSeamPair
occurrenceParentOccurrence(_:) occurrenceParentProduct(_:) (deprecated since v0.157.0)
PointSetLib.{properties,inertiaMatrix,barycentre,equation} Removed — no OCCT replacement

RC4 to RC5

Breaking Changes

Change Migration
GeomGridEval_Curve renamed to GeomEval_RepCurveDesc Updated bridge includes
LProp3d module absorbed into BRepLProp Changed LProp3d_CLProps.hxx to BRepLProp_CLProps.hxx
Geom2dLProp_CLProps2d constructor parameter reordering Verified constructor calls match RC5 signatures
TColGeom_Array1OfCurve typedefs removed Already using NCollection_Array1<Handle(Geom_Curve)>
.pxx implementation headers not shipped in xcframework GeomBndLib wrapping deferred

New APIs in RC5

  • GeomEval analytical curves: CircularHelixCurve, SineWaveCurve
  • GeomEval analytical surfaces: Ellipsoid, Hyperboloid, Paraboloid, Helicoid, HypParaboloid
  • Geom2dEval spirals: Archimedean, Logarithmic, CircleInvolute, SineWave
  • GeomFill_Gordon: Transfinite interpolation surface from crossing curve networks
  • PointSetLib: Point cloud centroid, inertia tensor, PCA analysis
  • Approx_BSplineApproxInterp: Constrained least-squares B-spline fitting
  • GeomEval TBezier/AHTBezier: Trigonometric and algebraic-hyperbolic-trigonometric basis curves/surfaces
  • GeomAdaptor_TransformedCurve: Rigid transformation adaptor for curves

Thread Safety Improvements

  • Reduced mutable global state in geometry evaluators
  • final keyword on evaluation methods enables devirtualization
  • Grid evaluation batch methods avoid per-call virtual dispatch

Not Wrappable

  • GeomBndLib: .pxx implementation headers not distributed in xcframework. Deferred until OCCT ships them.

RC3 to RC4

Breaking Changes

Change Migration
SelectMgr_ViewerSelector3d removed Replaced with SelectMgr_ViewerSelector.hxx
TopTools_ListIteratorOfListOfShape removed Replaced with TopTools_ListOfShape::Iterator
BRepExtrema_MapOfIntegerPackedMapOfInteger removed Migrated to NCollection_DataMap<int, TColStd_PackedMapOfInteger>
TColStd_MapIteratorOfPackedMapOfInteger removed Replaced with TColStd_PackedMapOfInteger::Iterator
RWObj_CafWriter::Perform() signature changed Migrated to 5-arg overload
RWPly_CafWriter::Perform() signature changed Same fix as OBJ

Deprecated Typedefs

OCCT 8.0 deprecates many collection typedefs. Key replacements:

Deprecated Replacement
TColgp_Array1OfPnt NCollection_Array1<gp_Pnt>
TColStd_Array1OfReal NCollection_Array1<double>
TopTools_ListOfShape NCollection_List<TopoDS_Shape>
TopTools_IndexedMapOfShape NCollection_IndexedMap<TopoDS_Shape, TopTools_ShapeMapHasher>
Standard_Integer / Standard_Real / Standard_Boolean int / double / bool

Full list of deprecated typedefs is available in the OCCT 8.0 migration scripts at Libraries/occt-src/adm/scripts/migration_800/.

Performance Improvements (automatic)

  • Devirtualized geometry evaluation on hot paths
  • Direct array members in BSpline/Bezier (no heap indirection)
  • Thread-local error handling
  • Contiguous TShape child storage
  • Robin Hood hash maps for internal collections

Rebuilding After Upgrade 

cd Libraries
rm -rf occt-src occt-build-* occt-install-*
cd ../Scripts && ./build-occt.sh

Build time: ~30-60 minutes. See guides/building-occt.md for details.