1 #define INKSCAPE_LPE_ANGLE_BISECTOR_CPP
2 /** \file
3 * LPE <angle_bisector> implementation, used as an example for a base starting class
4 * when implementing new LivePathEffects.
5 *
6 * In vi, three global search-and-replaces will let you rename everything
7 * in this and the .h file:
8 *
9 * :%s/ANGLE_BISECTOR/YOURNAME/g
10 * :%s/AngleBisector/Yourname/g
11 * :%s/angle_bisector/yourname/g
12 */
13 /*
14 * Authors:
15 * Johan Engelen
16 *
17 * Copyright (C) Johan Engelen 2007 <j.b.c.engelen@utwente.nl>
18 *
19 * Released under GNU GPL, read the file 'COPYING' for more information
20 */
22 #include "live_effects/lpe-angle_bisector.h"
24 // You might need to include other 2geom files. You can add them here:
25 #include <2geom/path.h>
26 #include <2geom/sbasis-to-bezier.h>
28 namespace Inkscape {
29 namespace LivePathEffect {
31 namespace AB {
33 class KnotHolderEntityLeftEnd : public LPEKnotHolderEntity
34 {
35 public:
36 virtual void knot_set(Geom::Point const &p, Geom::Point const &origin, guint state);
37 virtual Geom::Point knot_get();
38 };
40 class KnotHolderEntityRightEnd : public LPEKnotHolderEntity
41 {
42 public:
43 virtual void knot_set(Geom::Point const &p, Geom::Point const &origin, guint state);
44 virtual Geom::Point knot_get();
45 };
47 } // namespace TtC
49 LPEAngleBisector::LPEAngleBisector(LivePathEffectObject *lpeobject) :
50 Effect(lpeobject),
51 length_left(_("Length left"), _("Specifies the left end of the bisector"), "length-left", &wr, this, 0),
52 length_right(_("Length right"), _("Specifies the right end of the bisector"), "length-right", &wr, this, 250)
53 {
54 show_orig_path = true;
56 registerParameter( dynamic_cast<Parameter *>(&length_left) );
57 registerParameter( dynamic_cast<Parameter *>(&length_right) );
59 registerKnotHolderHandle(new AB::KnotHolderEntityLeftEnd(), _("Adjust the \"left\" end of the bisector"));
60 registerKnotHolderHandle(new AB::KnotHolderEntityRightEnd(), _("Adjust the \"right\" of the bisector"));
61 }
63 LPEAngleBisector::~LPEAngleBisector()
64 {
65 }
67 std::vector<Geom::Path>
68 LPEAngleBisector::doEffect_path (std::vector<Geom::Path> const & path_in)
69 {
70 using namespace Geom;
72 std::vector<Geom::Path> path_out;
74 // we assume that the path has >= 3 nodes
75 ptA = path_in[0].pointAt(1);
76 Point B = path_in[0].initialPoint();
77 Point C = path_in[0].pointAt(2);
79 double angle = angle_between(B - ptA, C - ptA);
81 dir = unit_vector(B - ptA) * Rotate(angle/2);
83 Geom::Point D = ptA - dir * length_left;
84 Geom::Point E = ptA + dir * length_right;
86 Piecewise<D2<SBasis> > output = Piecewise<D2<SBasis> >(D2<SBasis>(Linear(D[X], E[X]), Linear(D[Y], E[Y])));
88 return path_from_piecewise(output, LPE_CONVERSION_TOLERANCE);
89 }
90 namespace AB {
92 // TODO: make this more generic
93 static LPEAngleBisector *
94 get_effect(SPItem *item)
95 {
96 Effect *effect = sp_lpe_item_get_current_lpe(SP_LPE_ITEM(item));
97 if (effect->effectType() != ANGLE_BISECTOR) {
98 g_print ("Warning: Effect is not of type LPEAngleBisector!\n");
99 return NULL;
100 }
101 return static_cast<LPEAngleBisector *>(effect);
102 }
104 void
105 KnotHolderEntityLeftEnd::knot_set(Geom::Point const &p, Geom::Point const &/*origin*/, guint /*state*/)
106 {
107 LPEAngleBisector *lpe = get_effect(item);
109 Geom::Point const s = snap_knot_position(p);
111 double lambda = Geom::nearest_point(s, lpe->ptA, lpe->dir);
112 lpe->length_left.param_set_value(-lambda);
114 sp_lpe_item_update_patheffect (SP_LPE_ITEM(item), false, true);
115 }
117 void
118 KnotHolderEntityRightEnd::knot_set(Geom::Point const &p, Geom::Point const &/*origin*/, guint /*state*/)
119 {
120 LPEAngleBisector *lpe = get_effect(item);
122 Geom::Point const s = snap_knot_position(p);
124 double lambda = Geom::nearest_point(s, lpe->ptA, lpe->dir);
125 lpe->length_right.param_set_value(lambda);
127 sp_lpe_item_update_patheffect (SP_LPE_ITEM(item), false, true);
128 }
130 Geom::Point
131 KnotHolderEntityLeftEnd::knot_get()
132 {
133 LPEAngleBisector *lpe = get_effect(item);
134 return lpe->ptA - lpe->dir * lpe->length_left;
135 }
137 Geom::Point
138 KnotHolderEntityRightEnd::knot_get()
139 {
140 LPEAngleBisector *lpe = get_effect(item);
141 return lpe->ptA + lpe->dir * lpe->length_right;
142 }
144 } // namespace AB
146 /* ######################## */
148 } //namespace LivePathEffect
149 } /* namespace Inkscape */
151 /*
152 Local Variables:
153 mode:c++
154 c-file-style:"stroustrup"
155 c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
156 indent-tabs-mode:nil
157 fill-column:99
158 End:
159 */
160 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :