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1 | // Created on: 1993-03-10 |
2 | // Created by: JCV |
3 | // Copyright (c) 1993-1999 Matra Datavision |
4 | // Copyright (c) 1999-2014 OPEN CASCADE SAS |
5 | // |
6 | // This file is part of Open CASCADE Technology software library. |
7 | // |
8 | // This library is free software; you can redistribute it and/or modify it under |
9 | // the terms of the GNU Lesser General Public License version 2.1 as published |
10 | // by the Free Software Foundation, with special exception defined in the file |
11 | // OCCT_LGPL_EXCEPTION.txt. Consult the file LICENSE_LGPL_21.txt included in OCCT |
12 | // distribution for complete text of the license and disclaimer of any warranty. |
13 | // |
14 | // Alternatively, this file may be used under the terms of Open CASCADE |
15 | // commercial license or contractual agreement. |
16 | |
17 | #ifndef _Geom_OffsetCurve_HeaderFile |
18 | #define _Geom_OffsetCurve_HeaderFile |
19 | |
20 | #include <Standard.hxx> |
21 | #include <Standard_Type.hxx> |
22 | |
23 | #include <gp_Dir.hxx> |
24 | #include <Standard_Real.hxx> |
25 | #include <GeomAbs_Shape.hxx> |
26 | #include <Geom_Curve.hxx> |
27 | #include <Standard_Boolean.hxx> |
28 | #include <Standard_Integer.hxx> |
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29 | #include <GeomEvaluator_OffsetCurve.hxx> |
30 | |
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31 | class Geom_Curve; |
32 | class Standard_ConstructionError; |
33 | class Standard_RangeError; |
34 | class Standard_NoSuchObject; |
35 | class Geom_UndefinedDerivative; |
36 | class Geom_UndefinedValue; |
37 | class gp_Dir; |
38 | class gp_Pnt; |
39 | class gp_Vec; |
40 | class gp_Trsf; |
41 | class Geom_Geometry; |
42 | |
43 | |
44 | class Geom_OffsetCurve; |
45 | DEFINE_STANDARD_HANDLE(Geom_OffsetCurve, Geom_Curve) |
46 | |
47 | |
48 | //! This class implements the basis services for an offset curve |
49 | //! in 3D space. The Offset curve in this package can be a self |
50 | //! intersecting curve even if the basis curve does not |
51 | //! self-intersect. The self intersecting portions are not deleted |
52 | //! at the construction time. |
53 | //! An offset curve is a curve at constant distance (Offset) from |
54 | //! a basis curve in a reference direction V. The offset curve |
55 | //! takes its parametrization from the basis curve. |
56 | //! The Offset curve is in the direction of the normal N |
57 | //! defined with the cross product T^V, where the vector T |
58 | //! is given by the first derivative on the basis curve with |
59 | //! non zero length. |
60 | //! The distance offset may be positive or negative to indicate the |
61 | //! preferred side of the curve : |
62 | //! . distance offset >0 => the curve is in the direction of N |
63 | //! . distance offset <0 => the curve is in the direction of - N |
64 | //! |
65 | //! On the Offset curve : |
66 | //! Value (U) = BasisCurve.Value(U) + (Offset * (T ^ V)) / ||T ^ V|| |
67 | //! |
68 | //! At any point the Offset direction V must not be parallel to the |
69 | //! vector T and the vector T must not have null length else the |
70 | //! offset curve is not defined. So the offset curve has not the |
71 | //! same continuity as the basis curve. |
72 | //! |
73 | //! Warnings : |
74 | //! |
75 | //! In this package we suppose that the continuity of the offset |
76 | //! curve is one degree less than the continuity of the basis |
77 | //! curve and we don't check that at any point ||T^V|| != 0.0 |
78 | //! |
79 | //! So to evaluate the curve it is better to check that the offset |
80 | //! curve is well defined at any point because an exception could |
81 | //! be raised. The check is not done in this package at the creation |
82 | //! of the offset curve because the control needs the use of an |
83 | //! algorithm which cannot be implemented in this package. |
84 | //! |
85 | //! The OffsetCurve is closed if the first point and the last point |
86 | //! are the same (The distance between these two points is lower or |
87 | //! equal to the Resolution sea package gp) . The OffsetCurve can be |
88 | //! closed even if the basis curve is not closed. |
89 | class Geom_OffsetCurve : public Geom_Curve |
90 | { |
91 | |
92 | public: |
93 | |
94 | |
95 | |
96 | //! C is the basis curve, Offset is the distance between <me> and |
97 | //! the basis curve at any point. V defines the fixed reference |
98 | //! direction (offset direction). If P is a point on the basis |
99 | //! curve and T the first derivative with non zero length |
100 | //! at this point, the corresponding point on the offset curve is |
101 | //! in the direction of the vector-product N = V ^ T where |
102 | //! N is a unitary vector. |
103 | //! If isNotCheckC0 = TRUE checking if basis curve has C0-continuity |
104 | //! is not made. |
105 | //! Warnings : |
106 | //! In this package the entities are not shared. The OffsetCurve is |
107 | //! built with a copy of the curve C. So when C is modified the |
108 | //! OffsetCurve is not modified |
109 | //! |
110 | //! Raised if the basis curve C is not at least C1. |
111 | //! Warnings : |
112 | //! No check is done to know if ||V^T|| != 0.0 at any point. |
113 | Standard_EXPORT Geom_OffsetCurve(const Handle(Geom_Curve)& C, const Standard_Real Offset, const gp_Dir& V, const Standard_Boolean isNotCheckC0 = Standard_False); |
114 | |
115 | //! Changes the orientation of this offset curve. |
116 | //! As a result: |
117 | //! - the basis curve is reversed, |
118 | //! - the start point of the initial curve becomes the |
119 | //! end point of the reversed curve, |
120 | //! - the end point of the initial curve becomes the |
121 | //! start point of the reversed curve, and |
122 | //! - the first and last parameters are recomputed. |
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123 | Standard_EXPORT void Reverse() Standard_OVERRIDE; |
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124 | |
125 | //! Computes the parameter on the reversed curve for |
126 | //! the point of parameter U on this offset curve. |
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127 | Standard_EXPORT Standard_Real ReversedParameter (const Standard_Real U) const Standard_OVERRIDE; |
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128 | |
129 | //! Changes this offset curve by assigning C |
130 | //! as the basis curve from which it is built. |
131 | //! If isNotCheckC0 = TRUE checking if basis curve |
132 | //! has C0-continuity is not made. |
133 | //! Exceptions |
134 | //! Standard_ConstructionError if the curve C is not at least "C1" continuous. |
135 | Standard_EXPORT void SetBasisCurve (const Handle(Geom_Curve)& C, const Standard_Boolean isNotCheckC0 = Standard_False); |
136 | |
137 | //! Changes this offset curve by assigning V as the |
138 | //! reference vector used to compute the offset direction. |
139 | Standard_EXPORT void SetDirection (const gp_Dir& V); |
140 | |
141 | //! Changes this offset curve by assigning D as the offset value. |
142 | Standard_EXPORT void SetOffsetValue (const Standard_Real D); |
143 | |
144 | //! Returns the basis curve of this offset curve. |
145 | //! Note: The basis curve can be an offset curve. |
146 | Standard_EXPORT Handle(Geom_Curve) BasisCurve() const; |
147 | |
148 | //! Returns the global continuity of this offset curve as a |
149 | //! value of the GeomAbs_Shape enumeration. |
150 | //! The degree of continuity of this offset curve is equal |
151 | //! to the degree of continuity of the basis curve minus 1. |
152 | //! Continuity of the Offset curve : |
153 | //! C0 : only geometric continuity, |
154 | //! C1 : continuity of the first derivative all along the Curve, |
155 | //! C2 : continuity of the second derivative all along the Curve, |
156 | //! C3 : continuity of the third derivative all along the Curve, |
157 | //! G1 : tangency continuity all along the Curve, |
158 | //! G2 : curvature continuity all along the Curve, |
159 | //! CN : the order of continuity is infinite. |
160 | //! Warnings : |
161 | //! Returns the continuity of the basis curve - 1. |
162 | //! The offset curve must have a unique offset direction defined |
163 | //! at any point. |
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164 | Standard_EXPORT GeomAbs_Shape Continuity() const Standard_OVERRIDE; |
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165 | |
166 | //! Returns the reference vector of this offset curve. |
167 | //! Value and derivatives |
168 | //! Warnings : |
169 | //! The exception UndefinedValue or UndefinedDerivative is |
170 | //! raised if it is not possible to compute a unique offset |
171 | //! direction. |
172 | //! If T is the first derivative with not null length and |
173 | //! V the offset direction the relation ||T(U) ^ V|| != 0 |
174 | //! must be satisfied to evaluate the offset curve. |
175 | //! No check is done at the creation time and we suppose |
176 | //! in this package that the offset curve is well defined. |
177 | Standard_EXPORT const gp_Dir& Direction() const; |
178 | |
179 | //! Warning! this should not be called |
180 | //! if the basis curve is not at least C1. Nevertheless |
181 | //! if used on portion where the curve is C1, it is OK |
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182 | Standard_EXPORT void D0 (const Standard_Real U, gp_Pnt& P) const Standard_OVERRIDE; |
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183 | |
184 | //! Warning! this should not be called |
185 | //! if the continuity of the basis curve is not C2. |
186 | //! Nevertheless, it's OK to use it on portion |
187 | //! where the curve is C2 |
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188 | Standard_EXPORT void D1 (const Standard_Real U, gp_Pnt& P, gp_Vec& V1) const Standard_OVERRIDE; |
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189 | |
190 | //! Warning! this should not be called |
191 | //! if the continuity of the basis curve is not C3. |
192 | //! Nevertheless, it's OK to use it on portion |
193 | //! where the curve is C3 |
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194 | Standard_EXPORT void D2 (const Standard_Real U, gp_Pnt& P, gp_Vec& V1, gp_Vec& V2) const Standard_OVERRIDE; |
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195 | |
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196 | Standard_EXPORT void D3 (const Standard_Real U, gp_Pnt& P, gp_Vec& V1, gp_Vec& V2, gp_Vec& V3) const Standard_OVERRIDE; |
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197 | |
198 | |
199 | //! The returned vector gives the value of the derivative |
200 | //! for the order of derivation N. |
201 | //! |
202 | //! The following functions compute the value and derivatives |
203 | //! on the offset curve and returns the derivatives on the |
204 | //! basis curve too. |
205 | //! The computation of the value and derivatives on the basis |
206 | //! curve are used to evaluate the offset curve |
207 | //! |
208 | //! Warning: |
209 | //! The exception UndefinedValue or UndefinedDerivative is |
210 | //! raised if it is not possible to compute a unique offset |
211 | //! direction. |
212 | //! Raised if N < 1. |
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213 | Standard_EXPORT gp_Vec DN (const Standard_Real U, const Standard_Integer N) const Standard_OVERRIDE; |
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214 | |
215 | //! Returns the value of the first parameter of this |
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216 | //! offset curve. The first parameter corresponds to the |
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217 | //! start point of the curve. |
218 | //! Note: the first and last parameters of this offset curve |
219 | //! are also the ones of its basis curve. |
220 | Standard_EXPORT Standard_Real FirstParameter() const Standard_OVERRIDE; |
221 | |
222 | //! Returns the value of the last parameter of this |
223 | //! offset curve. The last parameter |
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224 | //! corresponds to the end point. |
225 | //! Note: the first and last parameters of this offset curve |
226 | //! are also the ones of its basis curve. |
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227 | Standard_EXPORT Standard_Real LastParameter() const Standard_OVERRIDE; |
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228 | |
229 | //! Returns the offset value of this offset curve. |
230 | Standard_EXPORT Standard_Real Offset() const; |
231 | |
232 | //! Returns True if the distance between the start point |
233 | //! and the end point of the curve is lower or equal to |
234 | //! Resolution from package gp. |
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235 | Standard_EXPORT Standard_Boolean IsClosed() const Standard_OVERRIDE; |
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236 | |
237 | //! Returns true if the degree of continuity of the basis |
238 | //! curve of this offset curve is at least N + 1. |
239 | //! This method answer True if the continuity of the basis curve |
240 | //! is N + 1. We suppose in this class that a normal direction |
241 | //! to the basis curve (used to compute the offset curve) is |
242 | //! defined at any point on the basis curve. |
243 | //! Raised if N < 0. |
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244 | Standard_EXPORT Standard_Boolean IsCN (const Standard_Integer N) const Standard_OVERRIDE; |
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245 | |
246 | //! Returns true if this offset curve is periodic, i.e. if the |
247 | //! basis curve of this offset curve is periodic. |
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248 | Standard_EXPORT Standard_Boolean IsPeriodic() const Standard_OVERRIDE; |
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249 | |
250 | //! Returns the period of this offset curve, i.e. the period |
251 | //! of the basis curve of this offset curve. |
252 | //! Exceptions |
253 | //! Standard_NoSuchObject if the basis curve is not periodic. |
254 | Standard_EXPORT virtual Standard_Real Period() const Standard_OVERRIDE; |
255 | |
256 | //! Applies the transformation T to this offset curve. |
257 | //! Note: the basis curve is also modified. |
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258 | Standard_EXPORT void Transform (const gp_Trsf& T) Standard_OVERRIDE; |
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259 | |
260 | //! Returns the parameter on the transformed curve for |
261 | //! the transform of the point of parameter U on <me>. |
262 | //! me->Transformed(T)->Value(me->TransformedParameter(U,T)) |
263 | //! is the same point as |
264 | //! me->Value(U).Transformed(T) |
265 | //! This methods calls the basis curve method. |
266 | Standard_EXPORT virtual Standard_Real TransformedParameter (const Standard_Real U, const gp_Trsf& T) const Standard_OVERRIDE; |
267 | |
268 | //! Returns a coefficient to compute the parameter on |
269 | //! the transformed curve for the transform of the |
270 | //! point on <me>. |
271 | //! |
272 | //! Transformed(T)->Value(U * ParametricTransformation(T)) |
273 | //! is the same point as |
274 | //! Value(U).Transformed(T) |
275 | //! This methods calls the basis curve method. |
276 | Standard_EXPORT virtual Standard_Real ParametricTransformation (const gp_Trsf& T) const Standard_OVERRIDE; |
277 | |
278 | //! Creates a new object which is a copy of this offset curve. |
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279 | Standard_EXPORT Handle(Geom_Geometry) Copy() const Standard_OVERRIDE; |
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280 | |
281 | //! Returns continuity of the basis curve. |
282 | Standard_EXPORT GeomAbs_Shape GetBasisCurveContinuity() const; |
283 | |
284 | |
285 | |
286 | |
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287 | DEFINE_STANDARD_RTTIEXT(Geom_OffsetCurve,Geom_Curve) |
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288 | |
289 | protected: |
290 | |
291 | |
292 | |
293 | |
294 | private: |
295 | |
296 | |
297 | Handle(Geom_Curve) basisCurve; |
298 | gp_Dir direction; |
299 | Standard_Real offsetValue; |
300 | GeomAbs_Shape myBasisCurveContinuity; |
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301 | Handle(GeomEvaluator_OffsetCurve) myEvaluator; |
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302 | |
303 | }; |
304 | |
305 | |
306 | |
307 | |
308 | |
309 | |
310 | |
311 | #endif // _Geom_OffsetCurve_HeaderFile |