Topological Data Structure

Topology defines the relationship between simple geometric entities, which can thus be linked together to represent complex shapes.

Abstract Topology is provided by six packages. The first three packages describe the topological data structure used in Open CASCADE:

- TopAbs

- TopLoc

- TopoDS

Three additional packages provide tools to access and manipulate this abstract topology:

- TopTools

- TopExp

- BRepTools

The TopLoc package provides resources to handle 3D local coordinate systems: Datum3D and Location. A Datum3D describes an elementary coordinate system, while a Location comprises a series of elementary coordinate systems.

The TopoDS package describes classes to model and build data structures that are purely topological.

The TopTools package provides basic tools to use on topological data structures.

The TopExp package provides classes to explore and manipulate the topological data structures described in the TopoDS package.

The BRepTools package provides classes to explore, manipulate, read and write BRep data structures. These more complex data structures combine topological descriptions with additional geometric information, and include rules for evaluating equivalence of different possible representations of the same object, for example, a point.

The TopAbs package provides general resources for topology-driven applications. It contains enumerations that are used to describe basic topological notions: topological shape, orientation and state. It also provides methods to manage these enumerations.