4fc6fc35dc1141c8067be4aaf4891fa249200a04
1 #define INKSCAPE_LPE_SKETCH_CPP
2 /** \file
3 * LPE <sketch> implementation
4 */
5 /*
6 * Authors:
7 * Johan Engelen
8 *
9 * Copyright (C) Johan Engelen 2007 <j.b.c.engelen@utwente.nl>
10 *
11 * Released under GNU GPL, read the file 'COPYING' for more information
12 */
14 #include "live_effects/lpe-sketch.h"
15 #include "display/curve.h"
16 #include <libnr/n-art-bpath.h>
18 // You might need to include other 2geom files. You can add them here:
19 #include <2geom/path.h>
20 #include <2geom/sbasis.h>
21 #include <2geom/sbasis-geometric.h>
22 #include <2geom/bezier-to-sbasis.h>
23 #include <2geom/sbasis-to-bezier.h>
24 #include <2geom/d2.h>
25 #include <2geom/sbasis-math.h>
26 #include <2geom/piecewise.h>
27 #include <2geom/crossing.h>
28 #include <2geom/path-intersection.h>
30 namespace Inkscape {
31 namespace LivePathEffect {
33 LPESketch::LPESketch(LivePathEffectObject *lpeobject) :
34 Effect(lpeobject),
35 // initialise your parameters here:
36 //testpointA(_("Test Point A"), _("Test A"), "ptA", &wr, this, Geom::Point(100,100)),
37 nbiter_approxstrokes(_("Strokes"), _("Draw that many approximating strokes"), "nbiter_approxstrokes", &wr, this, 5),
38 strokelength(_("Max stroke length"),
39 _("Maximum length of approximating strokes"), "strokelength", &wr, this, 100.),
40 strokelength_rdm(_("Stroke length variation"),
41 _("Random variation of stroke length (relative to maximum length)"), "strokelength_rdm", &wr, this, .3),
42 strokeoverlap(_("Max. overlap"),
43 _("How much successive strokes should overlap (relative to maximum length)."), "strokeoverlap", &wr, this, .3),
44 strokeoverlap_rdm(_("Overlap variation"),
45 _("Random variation of overlap (relative to maximum overlap)"), "strokeoverlap_rdm", &wr, this, .3),
46 ends_tolerance(_("Max. end tolerance"),
47 _("Maximum distance between ends of original and approximating paths (relative to maximum length)"), "ends_tolerance", &wr, this, .1),
48 parallel_offset(_("Parallel offset"),
49 _("Average distance from approximating path to original path"), "parallel_offset", &wr, this, 5.),
50 tremble_size(_("Max. tremble"),
51 _("Maximum tremble magnitude"), "tremble_size", &wr, this, 5.),
52 tremble_frequency(_("Tremble frequency"),
53 _("Avreage number of tremble periods in an approximating stroke"), "tremble_frequency", &wr, this, 1.),
54 nbtangents(_("Construction lines"),
55 _("How many construction lines (tangents) to draw"), "nbtangents", &wr, this, 5),
56 tgtscale(_("Scale"),
57 _("Scale factor relating curvature and length of construction lines (try 5*offset)"), "tgtscale", &wr, this, 10.0),
58 tgtlength(_("Max. length"), _("Maximum length of construction lines"), "tgtlength", &wr, this, 100.0),
59 tgtlength_rdm(_("Length variation"), _("Random variation of the length of construction lines"), "tgtlength_rdm", &wr, this, .3)
60 {
61 // register all your parameters here, so Inkscape knows which parameters this effect has:
62 //Add some comment in the UI: *warning* the precise output of this effect might change in future releases!
63 //convert to path if you want to keep exact output unchanged in future releases...
64 //registerParameter( dynamic_cast<Parameter *>(&testpointA) );
65 registerParameter( dynamic_cast<Parameter *>(&nbiter_approxstrokes) );
66 registerParameter( dynamic_cast<Parameter *>(&strokelength) );
67 registerParameter( dynamic_cast<Parameter *>(&strokelength_rdm) );
68 registerParameter( dynamic_cast<Parameter *>(&strokeoverlap) );
69 registerParameter( dynamic_cast<Parameter *>(&strokeoverlap_rdm) );
70 registerParameter( dynamic_cast<Parameter *>(&ends_tolerance) );
71 registerParameter( dynamic_cast<Parameter *>(¶llel_offset) );
72 registerParameter( dynamic_cast<Parameter *>(&tremble_size) );
73 registerParameter( dynamic_cast<Parameter *>(&tremble_frequency) );
74 registerParameter( dynamic_cast<Parameter *>(&nbtangents) );
75 registerParameter( dynamic_cast<Parameter *>(&tgtscale) );
76 registerParameter( dynamic_cast<Parameter *>(&tgtlength) );
77 registerParameter( dynamic_cast<Parameter *>(&tgtlength_rdm) );
80 nbiter_approxstrokes.param_make_integer();
81 nbiter_approxstrokes.param_set_range(0, NR_HUGE);
82 strokelength.param_set_range(1, NR_HUGE);
83 strokelength.param_set_increments(1., 5.);
84 strokelength_rdm.param_set_range(0, 1.);
85 strokeoverlap.param_set_range(0, 1.);
86 strokeoverlap.param_set_increments(0.1, 0.30);
87 ends_tolerance.param_set_range(0., 1.);
88 parallel_offset.param_set_range(0, NR_HUGE);
89 tremble_frequency.param_set_range(0.01, 100.);
90 tremble_frequency.param_set_increments(.5, 1.5);
91 strokeoverlap_rdm.param_set_range(0, 1.);
93 nbtangents.param_make_integer();
94 nbtangents.param_set_range(0, NR_HUGE);
95 tgtscale.param_set_range(0, NR_HUGE);
96 tgtscale.param_set_increments(.1, .5);
97 tgtlength.param_set_range(0, NR_HUGE);
98 tgtlength.param_set_increments(1., 5.);
99 tgtlength_rdm.param_set_range(0, 1.);
100 }
102 LPESketch::~LPESketch()
103 {
105 }
107 /*
108 Geom::Piecewise<Geom::D2<Geom::SBasis> >
109 addLinearEnds (Geom::Piecewise<Geom::D2<Geom::SBasis> > & m){
110 using namespace Geom;
111 Piecewise<D2<SBasis> > output;
112 Piecewise<D2<SBasis> > start;
113 Piecewise<D2<SBasis> > end;
114 double x,y,vx,vy;
116 x = m.segs.front()[0].at0();
117 y = m.segs.front()[1].at0();
118 vx = m.segs.front()[0][1][0]+Tri(m.segs.front()[0][0]);
119 vy = m.segs.front()[1][1][0]+Tri(m.segs.front()[1][0]);
120 start = Piecewise<D2<SBasis> >(D2<SBasis>(Linear (x-vx,x),Linear (y-vy,y)));
121 start.offsetDomain(m.cuts.front()-1.);
123 x = m.segs.back()[0].at1();
124 y = m.segs.back()[1].at1();
125 vx = -m.segs.back()[0][1][1]+Tri(m.segs.back()[0][0]);;
126 vy = -m.segs.back()[1][1][1]+Tri(m.segs.back()[1][0]);;
127 end = Piecewise<D2<SBasis> >(D2<SBasis>(Linear (x,x+vx),Linear (y,y+vy)));
128 //end.offsetDomain(m.cuts.back());
130 output = start;
131 output.concat(m);
132 output.concat(end);
133 return output;
134 }
135 */
139 //This returns a random perturbation. Notice the domain is [s0,s0+first multiple of period>s1]...
140 Geom::Piecewise<Geom::D2<Geom::SBasis> >
141 LPESketch::computePerturbation (double s0, double s1){
142 using namespace Geom;
143 Piecewise<D2<SBasis> >res;
145 //global offset for this stroke.
146 double offsetX = parallel_offset-parallel_offset.get_value();
147 double offsetY = parallel_offset-parallel_offset.get_value();
148 Point A,dA,B,dB,offset = Point(offsetX,offsetY);
149 //start point A
150 for (unsigned dim=0; dim<2; dim++){
151 A[dim] = offset[dim] + 2*tremble_size-tremble_size.get_value();
152 dA[dim] = 2*tremble_size-tremble_size.get_value();
153 }
154 //compute howmany deg 3 sbasis to concat according to frequency.
155 unsigned count = unsigned((s1-s0)/strokelength*tremble_frequency)+1;
156 for (unsigned i=0; i<count; i++){
157 D2<SBasis> perturb = D2<SBasis>();
158 for (unsigned dim=0; dim<2; dim++){
159 B[dim] = offset[dim] + 2*tremble_size-tremble_size.get_value();
160 perturb[dim].push_back(Linear(A[dim],B[dim]));
161 dA[dim] = dA[dim]-B[dim]+A[dim];
162 dB[dim] = 2*tremble_size-tremble_size.get_value();
163 perturb[dim].push_back(Linear(dA[dim],dB[dim]));
164 }
165 A = B;
166 dA = B-A-dB;
167 res.concat(Piecewise<D2<SBasis> >(perturb));
168 }
169 res.setDomain(Interval(s0,s0+count*strokelength/tremble_frequency));
170 return res;
171 }
174 // Main effect body...
175 Geom::Piecewise<Geom::D2<Geom::SBasis> >
176 LPESketch::doEffect_pwd2 (Geom::Piecewise<Geom::D2<Geom::SBasis> > const & pwd2_in)
177 {
178 using namespace Geom;
179 //If the input path is empty, do nothing.
180 //Note: this happens when duplicating a 3d box... dunno why.
181 if (pwd2_in.size()==0) return pwd2_in;
183 Piecewise<D2<SBasis> > output;
186 //init random parameters.
187 parallel_offset.resetRandomizer();
188 strokelength_rdm.resetRandomizer();
189 strokeoverlap_rdm.resetRandomizer();
190 tgtlength_rdm.resetRandomizer();
192 // some variables for futur use (for construction lines; compute arclength only once...)
193 // notations will be : t = path time, s = distance from start along the path.
194 Piecewise<SBasis> pathlength;
195 double total_length = 0;
197 //TODO: split Construction Lines/Approximated Strokes into two separate effects?
199 //----- Approximated Strokes.
200 std::vector<Piecewise<D2<SBasis> > > pieces_in = split_at_discontinuities (pwd2_in);
202 //work separately on each component.
203 for (unsigned pieceidx = 0; pieceidx < pieces_in.size(); pieceidx++){
205 Piecewise<D2<SBasis> > piece = pieces_in[pieceidx];
206 Piecewise<SBasis> piecelength = arcLengthSb(piece,.1);
207 double piece_total_length = piecelength.segs.back().at1()-piecelength.segs.front().at0();
208 pathlength.concat(piecelength + total_length);
209 total_length += piece_total_length;
212 //TODO: better check this on the Geom::Path.
213 bool closed = piece.segs.front().at0() == piece.segs.back().at1();
214 if (closed){
215 piece.concat(piece);
216 piecelength.concat(piecelength+piece_total_length);
217 }
219 for (unsigned i = 0; i<nbiter_approxstrokes; i++){
220 //Basic steps:
221 //- Choose a rdm seg [s0,s1], find coresponding [t0,t1],
222 //- Pick a rdm perturbation delta(s), collect 'piece(t)+delta(s(t))' over [t0,t1] into output.
224 // pick a point where to start the stroke (s0 = dist from start).
225 double s1=0.,s0 = ends_tolerance*strokelength+0.0001;//the root finder might miss 0.
226 double t1, t0;
227 double s0_initial = s0;
228 bool done = false;// was the end of the component reached?
230 while (!done){
231 // if the start point is already too far... do nothing. (this should not happen!)
232 if (!closed && s1>piece_total_length - ends_tolerance.get_value()*strokelength) break;
233 if ( closed && s0>piece_total_length + s0_initial) break;
235 std::vector<double> times;
236 times = roots(piecelength-s0);
237 t0 = times.at(0);//there should be one and only one solution!!
239 // pick a new end point (s1 = s0 + strokelength).
240 s1 = s0 + strokelength*(1-strokelength_rdm);
241 // don't let it go beyond the end of the orgiginal path.
242 // TODO/FIXME: this might result in short strokes near the end...
243 if (!closed && s1>piece_total_length-ends_tolerance.get_value()*strokelength){
244 done = true;
245 //!!the root solver might miss s1==piece_total_length...
246 if (s1>piece_total_length){s1 = piece_total_length - ends_tolerance*strokelength-0.0001;}
247 }
248 if (closed && s1>piece_total_length + s0_initial){
249 done = true;
250 if (closed && s1>2*piece_total_length){
251 s1 = 2*piece_total_length - strokeoverlap*(1-strokeoverlap_rdm)*strokelength-0.0001;
252 }
253 }
254 times = roots(piecelength-s1);
255 if (times.size()==0) break;//we should not be there.
256 t1 = times[0];
258 //pick a rdm perturbation, and collect the perturbed piece into output.
259 Piecewise<D2<SBasis> > pwperturb = computePerturbation(s0,s1);
260 pwperturb = compose(pwperturb,portion(piecelength,t0,t1));
261 output.concat(portion(piece,t0,t1)+pwperturb);
263 //step points: s0 = s1 - overlap.
264 //TODO: make sure this has to end?
265 s0 = s1 - strokeoverlap*(1-strokeoverlap_rdm)*(s1-s0);
266 }
267 }
268 }
271 //----- Construction lines.
272 //TODO: choose places according to curvature?.
274 //at this point we should have:
275 //pathlength = arcLengthSb(pwd2_in,.1);
276 //total_length = pathlength.segs.back().at1()-pathlength.segs.front().at0();
277 Piecewise<D2<SBasis> > m = pwd2_in;
278 Piecewise<D2<SBasis> > v = derivative(pwd2_in);
279 Piecewise<D2<SBasis> > a = derivative(v);
280 for (unsigned i=0; i<nbtangents; i++){
281 // pick a point where to draw a tangent (s = dist from start along path).
282 double s = total_length * ( i + tgtlength_rdm ) / (nbtangents+1.);
283 std::vector<double> times;
284 times = roots(pathlength-s);
285 double t = times.at(0);//there should be one and only one solution!
286 Point m_t = m(t), v_t = v(t), a_t = a(t);
287 //Compute tgt length according to curvature (not exceeding tgtlength) so that
288 // dist to origninal curve ~ 4 * (parallel_offset+tremble_size).
289 //TODO: put this 4 as a parameter in the UI...
290 //TODO: what if with v=0?
291 double l = tgtlength*(1-tgtlength_rdm)/v_t.length();
292 double r = pow(v_t.length(),3)/cross(a_t,v_t);
293 r = sqrt((2*fabs(r)-tgtscale)*tgtscale)/v_t.length();
294 l=(r<l)?r:l;
295 //collect the tgt segment into output.
296 D2<SBasis> tgt = D2<SBasis>();
297 for (unsigned dim=0; dim<2; dim++){
298 tgt[dim] = SBasis(Linear(m_t[dim]-v_t[dim]*l, m_t[dim]+v_t[dim]*l));
299 }
300 output.concat(Piecewise<D2<SBasis> >(tgt));
301 }
302 return output;
303 }
305 /* ######################## */
307 } //namespace LivePathEffect (setq default-directory "c:/Documents And Settings/jf/Mes Documents/InkscapeSVN")
308 } /* namespace Inkscape */
310 /*
311 Local Variables:
312 mode:c++
313 c-file-style:"stroustrup"
314 c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
315 indent-tabs-mode:nil
316 fill-column:99
317 End:
318 */
319 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :