--- /dev/null
+// Created on: 1996-06-06
+// Created by: Philippe MANGIN
+// Copyright (c) 1996-1999 Matra Datavision
+// Copyright (c) 1999-2014 OPEN CASCADE SAS
+//
+// This file is part of Open CASCADE Technology software library.
+//
+// This library is free software; you can redistribute it and/or modify it under
+// the terms of the GNU Lesser General Public License version 2.1 as published
+// by the Free Software Foundation, with special exception defined in the file
+// OCCT_LGPL_EXCEPTION.txt. Consult the file LICENSE_LGPL_21.txt included in OCCT
+// distribution for complete text of the license and disclaimer of any warranty.
+//
+// Alternatively, this file may be used under the terms of Open CASCADE
+// commercial license or contractual agreement.
+
+#ifndef _GeomConvert_CompBezierSurfacesToBSplineSurface_HeaderFile
+#define _GeomConvert_CompBezierSurfacesToBSplineSurface_HeaderFile
+
+#include <Standard.hxx>
+#include <Standard_DefineAlloc.hxx>
+#include <Standard_Handle.hxx>
+
+#include <Standard_Integer.hxx>
+#include <TColStd_HArray1OfInteger.hxx>
+#include <TColStd_HArray1OfReal.hxx>
+#include <TColgp_HArray2OfPnt.hxx>
+#include <Standard_Boolean.hxx>
+#include <TColGeom_Array2OfBezierSurface.hxx>
+#include <Standard_Real.hxx>
+#include <TColStd_Array1OfReal.hxx>
+#include <GeomAbs_Shape.hxx>
+class Standard_DimensionError;
+class Standard_NotImplemented;
+class Standard_ConstructionError;
+
+
+//! An algorithm to convert a grid of adjacent
+//! non-rational Bezier surfaces (with continuity CM) into a
+//! BSpline surface (with continuity CM).
+//! A CompBezierSurfacesToBSplineSurface object
+//! provides a framework for:
+//! - defining the grid of adjacent Bezier surfaces
+//! which is to be converted into a BSpline surface,
+//! - implementing the computation algorithm, and
+//! - consulting the results.
+//! Warning
+//! Do not attempt to convert rational Bezier surfaces using such an algorithm.
+//! Input is array of Bezier patch
+//! 1 2 3 4 -> VIndex [1, NbVPatches] -> VDirection
+//! -----------------------
+//! 1 | | | | |
+//! -----------------------
+//! 2 | | | | |
+//! -----------------------
+//! 3 | | | | |
+//! -----------------------
+//! UIndex [1, NbUPatches] Udirection
+//!
+//! Warning! Patches must have compatible parametrization
+class GeomConvert_CompBezierSurfacesToBSplineSurface
+{
+public:
+
+ DEFINE_STANDARD_ALLOC
+
+
+ //! Computes all the data needed to build a "C0"
+ //! continuous BSpline surface equivalent to the grid of
+ //! adjacent non-rational Bezier surfaces Beziers.
+ //! Each surface in the Beziers grid becomes a natural
+ //! patch, limited by knots values, on the BSpline surface
+ //! whose data is computed. Surfaces in the grid must
+ //! satisfy the following conditions:
+ //! - Coincident bounding curves between two
+ //! consecutive surfaces in a row of the Beziers grid
+ //! must be u-isoparametric bounding curves of these two surfaces.
+ //! - Coincident bounding curves between two
+ //! consecutive surfaces in a column of the Beziers
+ //! grid must be v-isoparametric bounding curves of these two surfaces.
+ //! The BSpline surface whose data is computed has the
+ //! following characteristics:
+ //! - Its degree in the u (respectively v) parametric
+ //! direction is equal to that of the Bezier surface
+ //! which has the highest degree in the u
+ //! (respectively v) parametric direction in the Beziers grid.
+ //! - It is a "Piecewise Bezier" in both u and v
+ //! parametric directions, i.e.:
+ //! - the knots are regularly spaced in each
+ //! parametric direction (i.e. the difference between
+ //! two consecutive knots is a constant), and
+ //! - all the multiplicities of the surface knots in a
+ //! given parametric direction are equal to
+ //! Degree, which is the degree of the BSpline
+ //! surface in this parametric direction, except for
+ //! the first and last knots for which the multiplicity is
+ //! equal to Degree + 1.
+ //! - Coincident bounding curves between two
+ //! consecutive columns of Bezier surfaces in the
+ //! Beziers grid become u-isoparametric curves,
+ //! corresponding to knots values of the BSpline surface.
+ //! - Coincident bounding curves between two
+ //! consecutive rows of Bezier surfaces in the Beziers
+ //! grid become v-isoparametric curves
+ //! corresponding to knots values of the BSpline surface.
+ //! Use the available consultation functions to access the
+ //! computed data. This data may be used to construct the BSpline surface.
+ //! Warning
+ //! The surfaces in the Beziers grid must be adjacent, i.e.
+ //! two consecutive Bezier surfaces in the grid (in a row
+ //! or column) must have a coincident bounding curve. In
+ //! addition, the location of the parameterization on each
+ //! of these surfaces (i.e. the relative location of u and v
+ //! isoparametric curves on the surface) is of importance
+ //! with regard to the positioning of the surfaces in the
+ //! Beziers grid. Care must be taken with respect to the
+ //! above, as these properties are not checked and an
+ //! error may occur if they are not satisfied.
+ //! Exceptions
+ //! Standard_NotImplemented if one of the Bezier
+ //! surfaces of the Beziers grid is rational.
+ Standard_EXPORT GeomConvert_CompBezierSurfacesToBSplineSurface(const TColGeom_Array2OfBezierSurface& Beziers);
+
+ //! Build an Ci uniform (Rational) BSpline surface
+ //! The higest Continuity Ci is imposed, like the
+ //! maximal deformation is lower than <Tolerance>.
+ //! Warning: The Continuity C0 is imposed without any check.
+ Standard_EXPORT GeomConvert_CompBezierSurfacesToBSplineSurface(const TColGeom_Array2OfBezierSurface& Beziers, const Standard_Real Tolerance, const Standard_Boolean RemoveKnots = Standard_True);
+
+ //! Computes all the data needed to construct a BSpline
+ //! surface equivalent to the adjacent non-rational
+ //! Bezier surfaces Beziers grid.
+ //! Each surface in the Beziers grid becomes a natural
+ //! patch, limited by knots values, on the BSpline surface
+ //! whose data is computed. Surfaces in the grid must
+ //! satisfy the following conditions:
+ //! - Coincident bounding curves between two
+ //! consecutive surfaces in a row of the Beziers grid
+ //! must be u-isoparametric bounding curves of these two surfaces.
+ //! - Coincident bounding curves between two
+ //! consecutive surfaces in a column of the Beziers
+ //! grid must be v-isoparametric bounding curves of these two surfaces.
+ //! The BSpline surface whose data is computed has the
+ //! following characteristics:
+ //! - Its degree in the u (respectively v) parametric
+ //! direction is equal to that of the Bezier surface
+ //! which has the highest degree in the u
+ //! (respectively v) parametric direction in the Beziers grid.
+ //! - Coincident bounding curves between two
+ //! consecutive columns of Bezier surfaces in the
+ //! Beziers grid become u-isoparametric curves
+ //! corresponding to knots values of the BSpline surface.
+ //! - Coincident bounding curves between two
+ //! consecutive rows of Bezier surfaces in the Beziers
+ //! grid become v-isoparametric curves
+ //! corresponding to knots values of the BSpline surface.
+ //! Knots values of the BSpline surface are given in the two tables:
+ //! - UKnots for the u parametric direction (which
+ //! corresponds to the order of Bezier surface columns in the Beziers grid), and
+ //! - VKnots for the v parametric direction (which
+ //! corresponds to the order of Bezier surface rows in the Beziers grid).
+ //! The dimensions of UKnots (respectively VKnots)
+ //! must be equal to the number of columns (respectively,
+ //! rows) of the Beziers grid, plus 1 .
+ //! UContinuity and VContinuity, which are both
+ //! defaulted to GeomAbs_C0, specify the required
+ //! continuity on the BSpline surface. If the required
+ //! degree of continuity is greater than 0 in a given
+ //! parametric direction, a deformation is applied locally
+ //! on the initial surface (as defined by the Beziers grid)
+ //! to satisfy this condition. This local deformation is not
+ //! applied however, if it is greater than Tolerance
+ //! (defaulted to 1.0 e-7). In such cases, the
+ //! continuity condition is not satisfied, and the function
+ //! IsDone will return false. A small tolerance value
+ //! prevents any modification of the surface and a large
+ //! tolerance value "smoothes" the surface.
+ //! Use the available consultation functions to access the
+ //! computed data. This data may be used to construct the BSpline surface.
+ //! Warning
+ //! The surfaces in the Beziers grid must be adjacent, i.e.
+ //! two consecutive Bezier surfaces in the grid (in a row
+ //! or column) must have a coincident bounding curve. In
+ //! addition, the location of the parameterization on each
+ //! of these surfaces (i.e. the relative location of u and v
+ //! isoparametric curves on the surface) is of importance
+ //! with regard to the positioning of the surfaces in the
+ //! Beziers grid. Care must be taken with respect to the
+ //! above, as these properties are not checked and an
+ //! error may occur if they are not satisfied.
+ //! Exceptions
+ //! Standard_DimensionMismatch:
+ //! - if the number of knots in the UKnots table (i.e. the
+ //! length of the UKnots array) is not equal to the
+ //! number of columns of Bezier surfaces in the
+ //! Beziers grid plus 1, or
+ //! - if the number of knots in the VKnots table (i.e. the
+ //! length of the VKnots array) is not equal to the
+ //! number of rows of Bezier surfaces in the Beziers grid, plus 1.
+ //! Standard_ConstructionError:
+ //! - if UContinuity and VContinuity are not equal to
+ //! one of the following values: GeomAbs_C0,
+ //! GeomAbs_C1, GeomAbs_C2 and GeomAbs_C3; or
+ //! - if the number of columns in the Beziers grid is
+ //! greater than 1, and the required degree of
+ //! continuity in the u parametric direction is greater
+ //! than that of the Bezier surface with the highest
+ //! degree in the u parametric direction (in the Beziers grid), minus 1; or
+ //! - if the number of rows in the Beziers grid is
+ //! greater than 1, and the required degree of
+ //! continuity in the v parametric direction is greater
+ //! than that of the Bezier surface with the highest
+ //! degree in the v parametric direction (in the Beziers grid), minus 1 .
+ //! Standard_NotImplemented if one of the Bezier
+ //! surfaces in the Beziers grid is rational.
+ Standard_EXPORT GeomConvert_CompBezierSurfacesToBSplineSurface(const TColGeom_Array2OfBezierSurface& Beziers, const TColStd_Array1OfReal& UKnots, const TColStd_Array1OfReal& VKnots, const GeomAbs_Shape UContinuity = GeomAbs_C0, const GeomAbs_Shape VContinuity = GeomAbs_C0, const Standard_Real Tolerance = 1.0e-4);
+
+ //! Returns the number of knots in the U direction
+ //! of the BSpline surface whose data is computed in this framework.
+ Standard_Integer NbUKnots() const;
+
+ //! Returns number of poles in the U direction
+ //! of the BSpline surface whose data is computed in this framework.
+ Standard_Integer NbUPoles() const;
+
+ //! Returns the number of knots in the V direction
+ //! of the BSpline surface whose data is computed in this framework.
+ Standard_Integer NbVKnots() const;
+
+ //! Returns the number of poles in the V direction
+ //! of the BSpline surface whose data is computed in this framework.
+ Standard_Integer NbVPoles() const;
+
+ //! Returns the table of poles of the BSpline surface
+ //! whose data is computed in this framework.
+ const Handle(TColgp_HArray2OfPnt)& Poles() const;
+
+ //! Returns the knots table for the u parametric
+ //! direction of the BSpline surface whose data is computed in this framework.
+ const Handle(TColStd_HArray1OfReal)& UKnots() const;
+
+ //! Returns the degree for the u parametric
+ //! direction of the BSpline surface whose data is computed in this framework.
+ Standard_Integer UDegree() const;
+
+ //! Returns the knots table for the v parametric
+ //! direction of the BSpline surface whose data is computed in this framework.
+ const Handle(TColStd_HArray1OfReal)& VKnots() const;
+
+ //! Returns the degree for the v parametric
+ //! direction of the BSpline surface whose data is computed in this framework.
+ Standard_Integer VDegree() const;
+
+
+ //! Returns the multiplicities table for the u
+ //! parametric direction of the knots of the BSpline
+ //! surface whose data is computed in this framework.
+ const Handle(TColStd_HArray1OfInteger)& UMultiplicities() const;
+
+ //! -- Returns the multiplicities table for the v
+ //! parametric direction of the knots of the BSpline
+ //! surface whose data is computed in this framework.
+ const Handle(TColStd_HArray1OfInteger)& VMultiplicities() const;
+
+ //! Returns true if the conversion was successful.
+ //! Unless an exception was raised at the time of
+ //! construction, the conversion of the Bezier surface
+ //! grid assigned to this algorithm is always carried out.
+ //! IsDone returns false if the constraints defined at the
+ //! time of construction cannot be respected. This occurs
+ //! when there is an incompatibility between a required
+ //! degree of continuity on the BSpline surface, and the
+ //! maximum tolerance accepted for local deformations
+ //! of the surface. In such a case the computed data
+ //! does not satisfy all the initial constraints.
+ Standard_EXPORT Standard_Boolean IsDone() const;
+
+
+
+
+protected:
+
+
+
+
+
+private:
+
+
+ //! It used internaly by the constructors.
+ Standard_EXPORT void Perform (const TColGeom_Array2OfBezierSurface& Beziers);
+
+
+ Standard_Integer myUDegree;
+ Standard_Integer myVDegree;
+ Handle(TColStd_HArray1OfInteger) myVMults;
+ Handle(TColStd_HArray1OfInteger) myUMults;
+ Handle(TColStd_HArray1OfReal) myUKnots;
+ Handle(TColStd_HArray1OfReal) myVKnots;
+ Handle(TColgp_HArray2OfPnt) myPoles;
+ Standard_Boolean isrational;
+ Standard_Boolean myDone;
+
+
+};
+
+
+#include <GeomConvert_CompBezierSurfacesToBSplineSurface.lxx>
+
+
+
+
+
+#endif // _GeomConvert_CompBezierSurfacesToBSplineSurface_HeaderFile
projects / occt.git / blobdiff