1 #define INKSCAPE_LPE_POWERSTROKE_CPP
2 /** \file
3 * @brief PowerStroke LPE implementation. Creates curves with modifiable stroke width.
4 */
5 /* Authors:
6 * Johan Engelen <j.b.c.engelen@utwente.nl>
7 *
8 * Copyright (C) 2010 Authors
9 *
10 * Released under GNU GPL, read the file 'COPYING' for more information
11 */
13 #include "live_effects/lpe-powerstroke.h"
15 #include "sp-shape.h"
16 #include "display/curve.h"
18 #include <2geom/path.h>
19 #include <2geom/piecewise.h>
20 #include <2geom/sbasis-geometric.h>
21 #include <2geom/svg-elliptical-arc.h>
22 #include <2geom/transforms.h>
24 namespace Inkscape {
25 namespace LivePathEffect {
27 LPEPowerStroke::LPEPowerStroke(LivePathEffectObject *lpeobject) :
28 Effect(lpeobject),
29 offset_1(_("Start Offset"), _("Handle to control the distance of the offset from the curve"), "offset_1", &wr, this),
30 offset_2(_("End Offset"), _("Handle to control the distance of the offset from the curve"), "offset_2", &wr, this),
31 offset_3(_("End Offset"), _("Handle to control the distance of the offset from the curve"), "offset_3", &wr, this)
32 // offset_points(_("Offset points"), _("Offset points"), "offset_points", &wr, this)
33 {
34 show_orig_path = true;
36 registerParameter( dynamic_cast<Parameter *>(&offset_1) );
37 registerParameter( dynamic_cast<Parameter *>(&offset_2) );
38 registerParameter( dynamic_cast<Parameter *>(&offset_3) );
39 // registerParameter( dynamic_cast<Parameter *>(&offset_points) );
41 /* register all your knotholder handles here: */
42 //registerKnotHolderHandle(new PowerStroke::KnotHolderEntityAttachMyHandle(), _("help message"));
43 }
45 LPEPowerStroke::~LPEPowerStroke()
46 {
48 }
51 void
52 LPEPowerStroke::doOnApply(SPLPEItem *lpeitem)
53 {
54 offset_1.param_set_and_write_new_value(*(SP_SHAPE(lpeitem)->curve->first_point()));
55 offset_2.param_set_and_write_new_value(*(SP_SHAPE(lpeitem)->curve->last_point()));
56 offset_3.param_set_and_write_new_value(*(SP_SHAPE(lpeitem)->curve->last_point()));
57 }
59 static void append_half_circle(Geom::Piecewise<Geom::D2<Geom::SBasis> > &pwd2,
60 Geom::Point const center, Geom::Point const &dir) {
61 using namespace Geom;
63 double r = L2(dir);
64 SVGEllipticalArc cap(center + dir, r, r, angle_between(Point(1,0), dir), false, false, center - dir);
65 Piecewise<D2<SBasis> > cap_pwd2(cap.toSBasis());
66 pwd2.continuousConcat(cap_pwd2);
67 }
69 Geom::Piecewise<Geom::D2<Geom::SBasis> >
70 LPEPowerStroke::doEffect_pwd2 (Geom::Piecewise<Geom::D2<Geom::SBasis> > const & pwd2_in)
71 {
72 using namespace Geom;
74 double t1 = nearest_point(offset_1, pwd2_in);
75 double offset1 = L2(pwd2_in.valueAt(t1) - offset_1);
77 double t2 = nearest_point(offset_2, pwd2_in);
78 double offset2 = L2(pwd2_in.valueAt(t2) - offset_2);
80 double t3 = nearest_point(offset_3, pwd2_in);
81 double offset3 = L2(pwd2_in.valueAt(t3) - offset_3);
83 /*
84 unsigned number_of_points = offset_points.data.size();
85 double* t = new double[number_of_points];
86 Point* offset = new double[number_of_points];
87 for (unsigned i = 0; i < number_of_points; ++i) {
88 t[i] = nearest_point(offset_points.data[i], pwd2_in);
89 Point A = pwd2_in.valueAt(t[i]);
90 offset[i] = L2(A - offset_points.data[i]);
91 }
92 */
94 // create stroke path where points (x,y) = (t, offset)
95 Path strokepath;
96 strokepath.start( Point(pwd2_in.domain().min(),0) );
97 strokepath.appendNew<Geom::LineSegment>( Point(t1, offset1) );
98 strokepath.appendNew<Geom::LineSegment>( Point(t2, offset2) );
99 strokepath.appendNew<Geom::LineSegment>( Point(t3, offset3) );
100 strokepath.appendNew<Geom::LineSegment>( Point(pwd2_in.domain().max(), 0) );
101 strokepath.appendNew<Geom::LineSegment>( Point(t3, -offset3) );
102 strokepath.appendNew<Geom::LineSegment>( Point(t2, -offset2) );
103 strokepath.appendNew<Geom::LineSegment>( Point(t1, -offset1) );
104 strokepath.close();
106 D2<Piecewise<SBasis> > patternd2 = make_cuts_independent(strokepath.toPwSb());
107 Piecewise<SBasis> x = Piecewise<SBasis>(patternd2[0]);
108 Piecewise<SBasis> y = Piecewise<SBasis>(patternd2[1]);
110 Piecewise<D2<SBasis> > der = unitVector(derivative(pwd2_in));
111 Piecewise<D2<SBasis> > n = rot90(der);
113 // output = pwd2_in + n * offset;
114 // append_half_circle(output, pwd2_in.lastValue(), n.lastValue() * offset);
115 // output.continuousConcat(reverse(pwd2_in - n * offset));
116 // append_half_circle(output, pwd2_in.firstValue(), -n.firstValue() * offset);
118 Piecewise<D2<SBasis> > output = compose(pwd2_in,x) + y*compose(n,x);
119 return output;
120 }
123 /* ########################
124 * Define the classes for your knotholder handles here
125 */
127 /*
128 namespace PowerStroke {
130 class KnotHolderEntityMyHandle : public LPEKnotHolderEntity
131 {
132 public:
133 // the set() and get() methods must be implemented, click() is optional
134 virtual void knot_set(Geom::Point const &p, Geom::Point const &origin, guint state);
135 virtual Geom::Point knot_get();
136 //virtual void knot_click(guint state);
137 };
139 } // namespace PowerStroke
140 */
142 /* ######################## */
144 } //namespace LivePathEffect
145 } /* namespace Inkscape */
147 /*
148 Local Variables:
149 mode:c++
150 c-file-style:"stroustrup"
151 c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
152 indent-tabs-mode:nil
153 fill-column:99
154 End:
155 */
156 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :