1 #ifndef INKSCAPE_LPE_TANGENT_TO_CURVE_H
2 #define INKSCAPE_LPE_TANGENT_TO_CURVE_H
4 /** \file
5 * LPE <tangent_to_curve> implementation, see lpe-tangent_to_curve.cpp.
6 */
8 /*
9 * Authors:
10 * Johan Engelen
11 * Maximilian Albert
12 *
13 * Copyright (C) Johan Engelen 2007 <j.b.c.engelen@utwente.nl>
14 * Copyright (C) Maximilian Albert 2008 <maximilian.albert@gmail.com>
15 *
16 * Released under GNU GPL, read the file 'COPYING' for more information
17 */
19 #include "live_effects/effect.h"
20 #include "live_effects/parameter/parameter.h"
21 #include "live_effects/parameter/point.h"
23 namespace Inkscape {
24 namespace LivePathEffect {
26 namespace TtC {
27 // we need a separate namespace to avoid clashes with LPEPerpBisector
28 class KnotHolderEntityLeftEnd;
29 class KnotHolderEntityRightEnd;
30 class KnotHolderEntityAttachPt;
31 }
33 class LPETangentToCurve : public Effect {
34 public:
35 LPETangentToCurve(LivePathEffectObject *lpeobject);
36 virtual ~LPETangentToCurve();
38 virtual Geom::Piecewise<Geom::D2<Geom::SBasis> >
39 doEffect_pwd2 (Geom::Piecewise<Geom::D2<Geom::SBasis> > const & pwd2_in);
41 /* the knotholder entity classes must be declared friends */
42 friend class TtC::KnotHolderEntityLeftEnd;
43 friend class TtC::KnotHolderEntityRightEnd;
44 friend class TtC::KnotHolderEntityAttachPt;
46 private:
47 ScalarParam angle;
49 ScalarParam t_attach;
50 ScalarParam length_left;
51 ScalarParam length_right;
53 Geom::Point ptA; // point of attachment to the curve
54 Geom::Point derivA;
56 Geom::Point C; // left end of tangent
57 Geom::Point D; // right end of tangent
59 LPETangentToCurve(const LPETangentToCurve&);
60 LPETangentToCurve& operator=(const LPETangentToCurve&);
61 };
63 } //namespace LivePathEffect
64 } //namespace Inkscape
66 #endif