BRepGraph Class Reference

Topology-geometry graph over TopoDS / BRep. More...

#include <BRepGraph.hxx>

Data Structures
class	CacheView
	Non-const view for managing transient cache values on nodes. More...
class	EditorView
	Non-const view for programmatic graph construction and structural editing. More...
class	MeshView
	Read-only view over mesh data with cache-first, persistent-fallback priority. More...
class	RefsView
	Read-only view for RefId/RefUID-based reference storage. More...
class	ShapesView
	Read-only view for TopoDS_Shape reconstruction from graph data. More...
class	TopoView
	Unified read-only view over topology definitions, adjacency, and representations. More...
class	UIDsView
	Read-only view for persistent unique identifiers. More...

Public Types
using	ReconstructCache = NCollection_DataMap<BRepGraph_NodeId, TopoDS_Shape>
	Shared cache for edge/vertex shapes during multi-face reconstruction.

Public Member Functions
	BRepGraph (const BRepGraph &)=delete
BRepGraph &	operator= (const BRepGraph &)=delete
	BRepGraph ()
	Default constructor. Creates an empty graph with default allocator.
	BRepGraph (const occ::handle< NCollection_BaseAllocator > &theAlloc)
	Construct with a custom allocator for internal collections.
	~BRepGraph ()
	Destructor.
	BRepGraph (BRepGraph &&) noexcept
	Move constructor.
BRepGraph &	operator= (BRepGraph &&) noexcept
	Move assignment operator.
void	Clear ()
	Reset the graph to an empty state. Increments generation and regenerates the graph GUID.
bool	IsDone () const
	Return true if the graph was successfully built.
bool	ValidateReverseIndex () const
	Verify reverse-index consistency against forward entity / reference-entry tables. Intended for debug builds and regression tests of incremental mutation paths.
const NCollection_DynamicArray< BRepGraph_ProductId > &	RootProductIds () const
	Return root product identifiers (products not referenced by any active occurrence). Maintained incrementally by Editor/EditorView mutations. Returns empty vector if the graph has not been built.
void	SetAllocator (const occ::handle< NCollection_BaseAllocator > &theAlloc)
	Replace the internal allocator and re-create all storage.
const occ::handle< NCollection_BaseAllocator > &	Allocator () const
	Return the current allocator.
const TopoView &	Topo () const
	Access topology definitions, representation access, adjacency queries, raw Product/Occurrence definition storage, and assembly classification.
const UIDsView &	UIDs () const
	Access unique identifiers.
CacheView &	Cache ()
	Access transient cache values through the stable grouped-view API. This is the only public cache interface.
const CacheView &	Cache () const
	Access transient cache values (const, read-only Get/Has/CacheKinds). This is the only public cache interface.
const RefsView &	Refs () const
	Access reference entries and their UIDs.
const ShapesView &	Shapes () const
	Access cached and fresh shape reconstruction.
EditorView &	Editor ()
	Access programmatic graph construction and mutation.
const EditorView &	Editor () const
	Const access to editor-specific state queries. Exposes IsDeferredMode() and ValidateMutationBoundary() on a const graph. All structural mutation methods require the non-const Editor() overload.
const MeshView &	Mesh () const
	Access mesh data with cache-first, persistent-fallback priority. For mesh cache writes and rep creation, use BRepGraph_Tool::Mesh.
BRepGraph_History &	History ()
	Access history subsystem directly. History is returned directly rather than through a lightweight view because it is already a self-contained query and recording subsystem with no per-view cached state.
const BRepGraph_History &	History () const
	Access history subsystem directly (const).
BRepGraph_LayerRegistry &	LayerRegistry ()
	Access registered graph layers.
const BRepGraph_LayerRegistry &	LayerRegistry () const
	Access registered graph layers (const).

Detailed Description

Topology-geometry graph over TopoDS / BRep.

Stores B-Rep topology as flat entity vectors (incidence-table model) with integer cross-references, enabling cache-friendly traversal, O(1) upward navigation via reverse indices, and parallel face-level geometry extraction.

Key design concepts:

• NodeId (Kind + Index): lightweight typed address into per-kind vectors.
• UID (Kind + Counter): persistent identity surviving compaction/reorder.
• RepId (Kind + Index): separate geometry/mesh addressing (Surface, Curve3D, Curve2D, Triangulation, Polygon) decoupled from topology nodes.
• CoEdge: half-edge entity owning PCurve data for each edge-face binding; seam edges use paired CoEdges with opposite Orientation (Parasolid convention).
• Lifecycle: BRepGraph_Builder::Add() populates from TopoDS_Shape; Editor() is the single mutation entry point for both structural creation/removal (Add*, Remove*, Append*) and field-level RAII-scoped mutation (Mut*()) with automatic cache invalidation and upward SubtreeGen propagation.

Per-occurrence data (orientation, location) lives on incidence refs. Definition types are aliases to BRepGraphInc entity structs.

Grouped View API

Related methods are grouped behind lightweight view objects. Include the corresponding header (e.g. BRepGraph_TopoView.hxx) to use.

Thread safety

Const query methods are safe for concurrent reads. Concurrent reads during active mutation still require external synchronization. Deferred invalidation (BRepGraph_DeferredScope) batches SubtreeGen propagation; concurrent Editor().Mut*() calls during deferred mode still require external serialization. BRepGraph_Builder::Add() is internally parallel when requested.

UID persistence

UIDs use monotonic counters (not vector indices), persisting across Compact() and node removal. Only BRepGraph::Clear() resets counters (new generation). See BRepGraph_UID.hxx for the serialization contract.

Extension model

Extend via BRepGraph_Layer (per-node attributes) or BRepGraph_TransientCache (algorithm-computed caches). Direct storage extension is not supported.

ID systems

Four ID types with different stability guarantees:

• NodeId (Kind + per-kind Index): fast graph-local address. NOT stable across Compact(). Use for in-graph traversal and short-lived algorithm temporaries.
• UID (Kind + monotonic Counter): persistent identity surviving Compact() and node removal. Use for cross-session storage, history tracking, and external references.
• RefId (Kind + per-kind Index): same stability as NodeId, but addresses reference entries (Shell->Solid binding, Face->Shell binding, CoEdge->Wire binding) rather than defs.
• RepId (Kind + per-kind Index): addresses geometry/mesh representation objects (Surface, Curve3D, Curve2D, Triangulation, Polygon) independently of topology nodes.

Iterator guide

Choose the iterator that matches your traversal need:

• BRepGraph_Iterator<NodeType>: flat sequential scan of ALL definitions of one kind (e.g. every FaceDef, skipping removed). Use for bulk per-kind algorithms.
• BRepGraph_DefsIterator / BRepGraph_RefsIterator: single-level typed children of one parent (e.g. active shells of one solid, coedge refs of one wire). Zero allocation. Use when you have a specific parent and need its direct children.
• BRepGraph_ChildExplorer: depth-first downward walk from a root with accumulated location/orientation per step. Use when visiting descendants across multiple levels or when the global transform matters. Supports Recursive and DirectChildren modes.
• BRepGraph_ParentExplorer: upward walk via reverse indices from a starting node. Use when tracing which shells/solids/compounds contain a given face or edge.
• BRepGraph_RelatedIterator: single-level semantic neighbors (adjacent faces, boundary edges, incident vertices). No structural descent; no location accumulation.
• BRepGraph_WireExplorer: ordered edge traversal within a single wire, following connectivity order (graph equivalent of BRepTools_WireExplorer).

Member Typedef Documentation

ReconstructCache

using BRepGraph::ReconstructCache = NCollection_DataMap<BRepGraph_NodeId, TopoDS_Shape>

Shared cache for edge/vertex shapes during multi-face reconstruction.

Constructor & Destructor Documentation

BRepGraph() [1/4]

BRepGraph::BRepGraph ( const BRepGraph & )

delete

BRepGraph() [2/4]

BRepGraph::BRepGraph

(

)

Default constructor. Creates an empty graph with default allocator.

BRepGraph() [3/4]

BRepGraph::BRepGraph ( const occ::handle< NCollection_BaseAllocator > & theAlloc )

explicit

Construct with a custom allocator for internal collections.

Parameters

[in]

theAlloc

allocator for internal collections (null uses CommonBaseAllocator)

~BRepGraph()

BRepGraph::~BRepGraph

(

)

Destructor.

BRepGraph() [4/4]

BRepGraph::BRepGraph ( BRepGraph && )

noexcept

Move constructor.

Member Function Documentation

Allocator()

const occ::handle< NCollection_BaseAllocator > & BRepGraph::Allocator

(

)

const

Return the current allocator.

Cache() [1/2]

CacheView & BRepGraph::Cache

(

)

Access transient cache values through the stable grouped-view API. This is the only public cache interface.

Cache() [2/2]

const CacheView & BRepGraph::Cache

(

)

const

Access transient cache values (const, read-only Get/Has/CacheKinds). This is the only public cache interface.

Clear()

void BRepGraph::Clear

(

)

Reset the graph to an empty state. Increments generation and regenerates the graph GUID.

Editor() [1/2]

EditorView & BRepGraph::Editor

(

)

Access programmatic graph construction and mutation.

Editor() [2/2]

const EditorView & BRepGraph::Editor

(

)

const

Const access to editor-specific state queries. Exposes IsDeferredMode() and ValidateMutationBoundary() on a const graph. All structural mutation methods require the non-const Editor() overload.

History() [1/2]

BRepGraph_History & BRepGraph::History

(

)

Access history subsystem directly. History is returned directly rather than through a lightweight view because it is already a self-contained query and recording subsystem with no per-view cached state.

Returns

history subsystem for tracking modifications

History() [2/2]

const BRepGraph_History & BRepGraph::History

(

)

const

Access history subsystem directly (const).

Returns

history subsystem for tracking modifications

IsDone()

bool BRepGraph::IsDone

(

)

const

Return true if the graph was successfully built.

LayerRegistry() [1/2]

BRepGraph_LayerRegistry & BRepGraph::LayerRegistry

(

)

Access registered graph layers.

Returns

layer registry for managing attribute layers

LayerRegistry() [2/2]

const BRepGraph_LayerRegistry & BRepGraph::LayerRegistry

(

)

const

Access registered graph layers (const).

Returns

layer registry for managing attribute layers

Mesh()

const MeshView & BRepGraph::Mesh

(

)

const

Access mesh data with cache-first, persistent-fallback priority. For mesh cache writes and rep creation, use BRepGraph_Tool::Mesh.

operator=() [1/2]

BRepGraph & BRepGraph::operator= ( BRepGraph && )

noexcept

Move assignment operator.

operator=() [2/2]

BRepGraph & BRepGraph::operator= ( const BRepGraph & )

delete

Refs()

const RefsView & BRepGraph::Refs

(

)

const

Access reference entries and their UIDs.

RootProductIds()

const NCollection_DynamicArray< BRepGraph_ProductId > & BRepGraph::RootProductIds

(

)

const

Return root product identifiers (products not referenced by any active occurrence). Maintained incrementally by Editor/EditorView mutations. Returns empty vector if the graph has not been built.

SetAllocator()

void BRepGraph::SetAllocator

(

const occ::handle< NCollection_BaseAllocator > &

theAlloc

)

Replace the internal allocator and re-create all storage.

Shapes()

const ShapesView & BRepGraph::Shapes

(

)

const

Access cached and fresh shape reconstruction.

Topo()

const TopoView & BRepGraph::Topo

(

)

const

Access topology definitions, representation access, adjacency queries, raw Product/Occurrence definition storage, and assembly classification.

UIDs()

const UIDsView & BRepGraph::UIDs

(

)

const

Access unique identifiers.

ValidateReverseIndex()

bool BRepGraph::ValidateReverseIndex

(

)

const

Verify reverse-index consistency against forward entity / reference-entry tables. Intended for debug builds and regression tests of incremental mutation paths.

Returns

true when every forward ref has a matching reverse entry.

---

The documentation for this class was generated from the following file:

• BRepGraph.hxx