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-- File: GeomAbs.cdl
-- Created: Mon Feb 22 15:03:40 1993
-- Author: Modelistation
-- <model@sdsun2>
---Copyright: Matra Datavision 1993
package GeomAbs
---Purpose: This package gives resources for Geometric applications
--
-- it contains :
-- CurveType enumeration to describe the different type of
-- curves
--
-- SurfaceType enumeration to describe the different type of
-- surfaces
--
-- Shape enumeration to describe the continuity of curve
-- or surface
--
-- CurveForm enumeration to describe the specific form of
-- curve
--
-- SurfaceForm enumeration to describe the specific form of
-- surface
--
-- BSplKnotDistribution enumeration to describe the
-- repartition of set of knots
--
-- UVSense enumeration to describe the orientation of
-- the parametric surface
uses Standard
is
enumeration CurveType
is Line, Circle, Ellipse, Hyperbola, Parabola,
BezierCurve, BSplineCurve,OtherCurve end;
---Purpose:
-- Identifies the type of a curve.
enumeration SurfaceType
is Plane, Cylinder, Cone ,Sphere ,Torus, BezierSurface,
BSplineSurface, SurfaceOfRevolution , SurfaceOfExtrusion,
OffsetSurface,OtherSurface end;
enumeration Shape is C0, G1, C1, G2, C2, C3, CN;
--- Purpose :
-- Provides information about the continuity of a curve:
-- - C0: only geometric continuity.
-- - G1: for each point on the curve, the tangent vectors
-- "on the right" and "on the left" are collinear with the same orientation.
-- - C1: continuity of the first derivative. The "C1" curve is
-- also "G1" but, in addition, the tangent vectors " on the
-- right" and "on the left" are equal.
-- - G2: for each point on the curve, the normalized
-- normal vectors "on the right" and "on the left" are equal.
-- - C2: continuity of the second derivative.
-- - C3: continuity of the third derivative.
-- - CN: continuity of the N-th derivative, whatever is the
-- value given for N (infinite order of continuity).
-- Also provides information about the continuity of a surface:
-- - C0: only geometric continuity.
-- - C1: continuity of the first derivatives; any
-- isoparametric (in U or V) of a surface "C1" is also "C1".
-- - G2: for BSpline curves only; "on the right" and "on the
-- left" of a knot the computation of the "main curvature
-- radii" and the "main directions" (when they exist) gives the same result.
-- - C2: continuity of the second derivative.
-- - C3: continuity of the third derivative.
-- - CN: continuity of any N-th derivative, whatever is the
-- value given for N (infinite order of continuity).
-- We may also say that a surface is "Ci" in u, and "Cj" in v
-- to indicate the continuity of its derivatives up to the order
-- i in the u parametric direction, and j in the v parametric direction.
enumeration SurfaceForm is
PlanarForm, ConicalForm, CylindricalForm, ToroidalForm, SphericalForm,
RevolutionForm, RuledForm, QuadricForm, OtherSurfaceForm;
--- Purpose :
-- This enumeration is used to note specific surface form.
enumeration CurveForm is
PolylineForm, CircularForm, EllipticForm, HyperbolicForm, ParabolicForm,
OtherCurveForm;
--- Purpose :
-- This enumeration is used to note specific curve form.
enumeration BSplKnotDistribution is
NonUniform, Uniform, QuasiUniform, PiecewiseBezier;
--- Purpose :
-- This enumeration is used in the classes BSplineCurve and
-- BSplineSurface to describe the repartition of set of knots.
-- (comments in classes BSplineCurve and BSplineSurface)
enumeration UVSense is SameUV, SameU, SameV, OppositeUV;
--- Purpose :
-- This enumeration is used in the class RectangularTrimmedSurface
-- to compare the orientation of the basic surface and the orientation
-- of the trimmed surface and in the class ElementarySurface to know
-- the direction of parametrization by comparison with the default
-- construction mode.
enumeration IsoType is IsoU,IsoV,NoneIso;
---Purpose: this enumeration describes if a curve is an U isoparaetric
-- or V isoparametric
enumeration JoinType is Arc, Tangent, Intersection;
---Purpose: Characterizes the type of a join, built by an algorithm for
-- constructing parallel curves, between two consecutive
-- arcs of a contour parallel to a given contour.
end GeomAbs;
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