CommitLineData
b311480e 1-- Created on: 1991-10-28
2-- Created by: Remi LEQUETTE
3-- Copyright (c) 1991-1999 Matra Datavision
5--
6-- The content of this file is subject to the Open CASCADE Technology Public
7-- License Version 6.5 (the "License"). You may not use the content of this file
10--
11-- The Initial Developer of the Original Code is Open CASCADE S.A.S., having its
12-- main offices at: 1, place des Freres Montgolfier, 78280 Guyancourt, France.
13--
15-- distributed on an "AS IS" basis, without warranty of any kind, and the
16-- Initial Developer hereby disclaims all such warranties, including without
17-- limitation, any warranties of merchantability, fitness for a particular
18-- purpose or non-infringement. Please see the License for the specific terms
19-- and conditions governing the rights and limitations under the License.
20
7fd59977 21
22
23package TopTrans
24
25 ---Purpose: This package provides algorithms to compute
26 -- complex transitions. A transition is the status of
27 -- geometry near the boundary of a Shape. An example
28 -- is the intersection of a curve and a surface
29 -- enclosing a solid , the transition tells if the
30 -- parts of the curve just before and just after the
31 -- intersection are inside, outside or on the
32 -- boundary of the solid.
33 --
34 -- The difficulty with transitions arise when dealing
35 -- with trimmed geometries like edges and faces. When
36 -- the geometric intersections are inside the trimmed
37 -- geometry the transition is usually computed by the
38 -- intersection algorithms as the trimming can be
39 -- safely ignored. If the intersection falls on the
40 -- trimming boundaries one must consider the
41 -- neighbouring entities. Consider as an example the
42 -- intersection of a curve and a solid, if the
43 -- intersection falls on an edge of the solid it does
44 -- not falls inside the two faces adjacent to the
45 -- edge, a complex transition occurs.
46 --
47 -- This package provides two classes :
48 --
49 -- * CurveTransition is used to compute complex
50 -- transitions with an other curve.
51 --
52 -- * SurfaceTransition is used to compute complex
53 -- transitions in 3D space.
54 --
55 -- The curves and surfaces are given by a first or
56 -- second order approximation around the intersection
57 -- point. For a curve, the tangent vector or the
58 -- osculating circle. For a surface the normal vector
59 -- or the osculating quadric.
60
61uses
62 Standard,
63 TCollection,
64 TColStd,
65 gp,
66 TopAbs
67
68is
69
70 class Array2OfOrientation instantiates
71 Array2 from TCollection (Orientation from TopAbs);
72
73 class CurveTransition;
74
75 class SurfaceTransition;
76
77end TopTrans;